* GB785658 (A)

Description: GB785658 (A) ? 1957-10-30

Gasket

Description of GB785658 (A)

PATENT SPECIFICATION Invrentor: JOSEPH BENJAMIN VICTOR V Date of Application and filing Complete Specification: Sept 14, 1955. Hi -a/'No 26331/55. Complete Specification Published: Oct 30, 1957. Index at acceptance:-Class 122 ( 3), N 1 C. International Classification:-FO 61. ICOLMIPLETE SPECIFICATION Gasket We, VICTOR MANUFACTURING AND GASKET COMPANY,, a corporation duly organzed under the laws of the State of Iliinois, United States of America of 5,750 Roosevelt Road, Chicago, State of Illlinois, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is t be performed, to be particularly described in and iby the following statement: - This invention relates to gaskets, more particularly it relates to metal faced gaskets, of compressible material, and has for its principal object 'a new and improved gasket of this type. It is a main object of the invention to provide a metal faced oompressible material gasket that is highly flexible and highly compressible and capable of tightly sealing two abutting surfaces against high pressures at high temperatures, even, though those surfaces contain irregularities and are not truly planar. Another object of the invention is to provide a highly flexible metal faced gasket that is unitary and capable of being handled without damage. Another object of the invention is to provide a metal faced compressible material cylinder head gasket that is highly flexible and highly compressible and is impervious, to oils, gas, coolants and heat, and is capable of forming and maintaining a tight seal between

the iblock and head of an internal combustion engine. Another object of the invention is to provide a metal faced asbestos cylinder head gasket possessing good thermal characteristics so that heat transfer from a block to the head of an internal combustion engine will not be interfered with by the gaskets. Another object of the invention is to provide a metal faced asbestos gasket that can be manufactured at low cost without sacrificing quality. Further objects of the invention not specifically mentioned here will be apparent from the detailed description and, dlaims which follow, reference being had to the accompanying V 1 drawings in which a preferred emibodiment of the invention is shown by way of example and in, which: Fig 1 is a fragmentary plan view of a cylinder head gasket showing the invention;' Fig 2 is a cross sectional view taken along the line 2-2 of Fig 1 looking in: the direction of the arrows and drawn to, an enlarged scale; Fig 3 is a cross sectional view along the line 3-3 ' of Fig, 1, looking in the direction of the arrows andi also drawn to an enlarged scale;' Fig 4 is a plan view of a modified form of cylinder head gasket showing the invention; and Fig 5 is a fragmentary cross sectional view along the line 5-5 of Fig, 4, looking in the direction of the arrows and, drawn to, an enlarged scale. Metal faced asbestos gaskets are commonly employed to seal two abutting machine parts so as to provide a tight joint itherebetween, particularly when those parts are subjected to high pressures and temperatures Thus, for example, cylinder head gaskets in an internal combustion engine interposed between the block and head frequently consist of a sheet of heatproof material, such as asbestos, sandwiched between thin metal facings usually composed of steel or copper The present invention relates to gaskets of this type, and in the embodiment sho wnby way of example a cylinder head gasket is illustrated. Although the sealing surface of the head and block Ware supposed, to be planar and smooth, and when the head is drawn tightly down onto the block are supposed to be truly parallel, it frequently happens that these surfaces are not truly planar, nor are they brought to truly parallel position. In the prior art of which we are aware, in most instances metal faced gaskets of this type have been provided with numerous' grommets or fiangelike portions which hold the members together and which also stiifen the gasket so that it becomes difficult to form, and maintain a pressure fluid-tight joint in cases where the block or head contains small imperfections. 85,658 s O Furthenmore, cylinder heads frequently war slightly so that

the surfaces of the head an, block can never be brought into true parallel ism. Also in the prior art of which we are awar 4 are gaskets of this type in which the metr facings are cut away exposing large areas o the compressible material, such as asbestos into direct contact with the block and head Although such material is treated to preven its sticking or adhering to the block or head nevertheless it may stick to these members; anc when a large area of compressible material i: exposed to the metal parts and sticks thereto. removal of the gasket results in tearing out o: large areas of the compressible material whice must be removed from the block or head before a new gasket can be placed. The present invention provides a metal faced gasket consisting of a central sheet of compressible material, preferably an asbestos which has been treated in the making of the sheet with resinous organic binders such as urea formaldehyde or phenol formaldehyde, or inorganic binders such as Portland cement or sodium silicate, which render it impervious to oils, water, gas and coolants, without impairing its flexibility The sheet of material is cut to fit accurately with the engine block and-contains openings registered with the cylinder, coolant passages, oil passages and bolt holes. Registered with and engaging the opposite faces of this compressible sheet are thin metallic facing members, preferably copper or steel, having the same shape as the sheet of asbestos. In addition to the service openings, these metal facings also contain a plurality of small perforations spaced close together and extending over the entire area of the facing, the diameter of the perforations being preferably approximately equal to the thickness of the gasket when compressed. These numerous small perforations have been found to add flexibility uto the gasket, better enabling itto accurately conform to and for-n a tight seal between the machine parts even when, those parts contain imperfections and irregularities As the head is being tightened onto the block and the gasket compressed, the asbestos may be forced into and through the perforations in ithe facings thereby to come into direct contact with the engine parts. Should the asbestos thus engaging the engine parts stick thereto, the points of sticking will be separated and the gasket can be peeled off of the engine part without difficulty No large sections of asbestos being in contact with the metal, the sheet will not be torn, and cleaning of the machine parts preparatory to the insertion of a new gasket is therefore held to a minimum. In order that the sheet of compressible material and two facing members forming the gaskets can be handled as a unit, it is necessary

that they be securely fastened together. p In the preferred form of the present invend tons the parts of the gasket are secured 1-together either by grommets spaced in certain ones of the centermost abolt holes in the gasket e or by cylinder opening flanges In either event, 70 1 the securing means are relatively few in numf ber and are so located as not to impair the :, compressibility of the gasket. Referring now to the drawings in more det tail it will be seen that the cylinder head gas 75 1, ket shown by way of example consists of a dcentral sheet of compressible material 1, pres ferably asbestos treated with a resinous organic >binder such as urea formaldehyde or phenol f formaldehyde that renders it impervious to oil, 80 1 gas and coolants, without impairing the ability of the asbestos to withstand heat Located on the upper and lower faces of the central sheet 1 1 are facing members 2 which are thin sheets of metal, either copper or steel 85 As will be seen in Fig 1, the gasket contains combustion openings 3 coolant openings 4, the particular size and shape of which forms no part of the present invention and will be )varied to adapt the gaskets to various engine 90 specifications The gasket also contains an oil hole 5 and bolt holes 6 which likewise will be varied. The metal facings 2 contain a plurality of small perforations 7 located in uniformly 95 spaced rows, with the perforations uniformly spaced in the row In one embodiment of the invention the perforations 7 are 1/16 of an inch in diameter and are spaced ten to the inch in the row and the rows spaced like 100 wise ten to the inch In this embodiment it will be seen that 10/16 of the length of the row will be accompanied by perforations and 6/16 by the metal remaining between adjacent ones of the perforations With an arrange 105 ment of this kind, slightly over 30 % of each square inch of the metal facing is occupied by perforations. gin the embodiment of the invention shown in Fig 1, the compressible sheet 1 and facings 110 2 are held together by the flanges 8 which surround the combustion openings 3 These flanges, which may likewise be formed of steel or copper are, preferable when the gasket is to be used in high compression ratio engines 115 such as are frequently encountered. En the embodiment of the invention shown in Fig 4, the compressible material 1 and facings 2 are held together by grommets 9 located in, alternate ones of the bolt holes 6 120 disposed on the longitudinal median lines of the gasket The combustion openings 3 are not faced, this type of gasket being satisfactory for use in internal combustion engines having relatively low compression ratios In both embodi 125 ments the fastening means are located in regions where the bolt pressure is highest, and consequently there is no interference to the

forming of a tight seal between the engine and the block 130 78 + 55518 785,658 3 With the central compressible sheet 1 composed of resin treated asbestos that is impervious to oils, gas and coolants' and capable of withstanding high heat, the gasket of the present invention is capable of forming and maintaining a tight seal betweenthe block and head, even though one or both of the gasket engaging surfaces contains irregularities rendering it non-planar As the gasket is compressed between these plarts, the compressible material may flow through the perforations into direct engagement with ithe head or block. Because of the flexibility added to the thin sheet metal facings by the perforations therein, the gasket ca readily conform to irregulartities in the surfaces and form a tight seal therewith Should the asbestos which has flowed through the perforations stick to the block or head, the separation of the points of sticking produced by the thin waft of metal, intervening between adjacent perforations permits peeling the gasket off of the head or block notwithstanding the sticking of the asbestos thereto, Cleaning of the surfaces preparatory to the insertion of a new gasket is therefore While we have chosen to illustrate our invention by showing and describing it as applied to a cylinder head gasket composed of asbestos and sheet metal facings, we have done so by way of example, as She gasket may be put to other uses and the compressible material may be material other than asbestos.

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* GB785659 (A)

Description: GB785659 (A) ? 1957-10-30

Method of purifying benzene

Description of GB785659 (A)

COMPLETE SPECIFICATION Method of Purifyilag Benzene We, UNITED STATES STEEL CORPORATION, a Corporation organized and existing under the Laws of the State Gf New Jersey, United States of America, doing business at 525, William Penn Place, Pittsburgh 30, State of Pennsylvania, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the fo1- lowing statement: This invention relates to the production of benzene of high purity by removal of the contaminants associated with the product as derived from coke-oven light oil. Benzene is a basic commodity of the chenii- cal industry. When derived from coke-oven light oil, however, it contains objectionable contaminants, even after the crude product has been washed with sulphuric acid, neutralized and fractionally distilled. These contaminants include thiophene, carbon disulphide and various olefins (principally cyclohexane) and paraffins or naphthenes (principally methylcyclohexane), the presence of which lowers the freezing point to between 4.83 and 5.23 C. Such contaminants cannot be tolerated in most chemical processes using benzene and users therefore specify thiophene and carbon disulphide contents of less than 0.1 ppm., the absence of any detectable olefins and a freezing point of 5.40 C. or higher. It has been possible to meet such specifications, using benzene from light oil, only at great cost with low yields. Much eltort has accordingly been devoted to the development of improved purification methods but none of those proposed has, to our knowledge, been successful in producing a high yield of high-purity product without excessive cost or serious operating difliculties. We have invented a novel method for benzene purification which is simple, relatively inexpensive and highly effective, yet gives amazingly high yields. The product of our method easily meets the rigid specifications set by benzene users, e.g., the freezing point exceeds 5.40 C., the thiophene and carbon disulphide present are less than 0.1 ppm. and the presence of olefins is not detectable. According to the invention there is provided a method of removing contaminants from benzene including the steps of bringing a controlled amount of free chlorine into contact with the benzene, promoting halogenation of the impurities in the benzene by irradiating the latter with ultra-violet light, subjecting the benzene to alkaline extraction with water, decanting the benzene from the water, and then

distilling the benzene, while maintaining the benzene free from contact with iron at least until substantially all the free chlorine has reacted, and maintaining the benzene after extraction free from contact with iron compounds until distilled, characterised in that the step of alkaline extraction includes intro ducing the chlorinated, irradiated benzene into the chamber of a multistageontactor in one direction and introducing water thereinto in the other direction in a votume ratio of benzene to water of from 0.5 to 4, maintaining the PH of the water from 7 to 12 and the tedl- perature from 4u to 80 G, thereby hydrolyzing the unstable chlorinated contaminants in the benzene into thermally stable compounds which remain as bottoms on distillation of the benzene, and maintaining a continuous water phase at the end of the chamber at which the benzene enters and a continuous benzene phase at the end at which the water enters. Benzene of industrial grade which has been acid-washed, neutralised and fractionally dis tilled, is first chlorinated by direct contact with chlorine in a packed column. This chlorinates the thiophene and the olefins. The benzene with chlorine in solution is then sub.- jected to irradiation for a short time by ultraviolet light. This causes chlorination of the paraffins and naphthenes and the conversion of carbon disulphide to carbon tetrachloride. The carbon tetrachloride polymerizes with other contaminants. The 'benzene thus treated is washed with warm water in a packed column to remove dissolved hydrogen chloride formed by the chlorination and to hydr- lyze some of the chlorinated contaminants, the water having a pH value of from 7 to 12 and a temperature from 40 to 800 C. After gravity separation of water from the benzene, the latter is fractionaily distilled giving pure product overhead and leaving all remaining contaminants as residue. A condition essential to the achievement of the high yields of 98 or 99% obtainable by our method, is the maintenance of the benzene in the chlorinating steps, free from contact with ferrous metal. Such contact cata- lyzes the chlorination of benzene which is, of course, undesirable. The extraction and distillation steps must be carried out in vessels of corrosion-resistant metal, e.g., stainless steel. A complete understanding of the invention may be obtained from the following detailed description and explanation which refer to the accompanying drawings illustrating the present preferred practice. In the drawings : - Figure 1 is a diagrammatic represnrtion of a system for carrying out our method; and Figure 2 is an axial section through the irradiation chamber. Referring in detail to the drawing, we deliver industrial-grade benzene from a tank 10 to the top of a packed column 12 at a

temperature of from 20 to 40" C. by a pump 11. The column and packing are of glass, stenewafe or other non-metallic materiaL The raw benzene is that resulting from crude benzone distilled from coke-oven light oil, after acid washing, neutralization and fractional distillation thereof. It may contain contaminants such as thiophene up to 1560 ppm., carbon disulphide up to 1C00 ppm., olefins up to 0.2%, paraffins up to 0.4%, and have a freezing point between 4.85 and 5.40" C. We supply gaseous chlorine from a source 13 through a meter and control valve 14 and a diffuser 15, also non-metallic, located at a point above the bottom of column 11. The amount of chlorine added to the benzene in column 12 may be from .5 to 2.0% of the weight of benzene. Ordinarily, about 1% is sufficient to produce a substantially pure prb duct benzene. As the benzene descends the column, the chlorine is dissolved therein and reacts with the dissolved thiophene, forming hydrogen chloride. Absorption of chlorine by the benzene imparts a distinct yellow coloration thereto. The height of the column abve the diffuser should be sufficient to retain the hydrogen chloride dissolved in the benzene, for reaction with the contaminants, and thus reduce the chlorine consumption. A height of from three to fifteen feet is adequate. The pressure of the source of chlorine, of course, must exceed the head of benzene. Diffuser 15 should be from two to six feet above the bottom of the column and the rate of benzene feed to the column such that a period of from one to three minutes is spent in travel from the level of the diffuser to the bottom of the column. This not only allows time for chlorination of thiophene by normal substitution, but also for some chlorination of ole- fins by addition of chlorine and hydrogen chloride. If the benzene feed is at a temperature of 30 C., the temperature at the bottom of the column will be about 35 C as a result of the chlorination reactions taking place n the column. Any hydrogen chloride not retained in the benzene is conducted from the top of column 12 to a vapor scrubber 16 for absorption in a lime slurry or a caustic soda solution. Alternatively, the hydrogen chloride may be recovered in any cenvem.ent manner, if desired. In order to promote chlorination of the contaminants remaining unreacted in the solution -of chlorine and hydrogen chloride in benzene at the bottom of column 12, we subject the solution to irradiation by ultra-violet light. To this end, the solution is delivered by a pump 17 to the inlet 18 of a double-walled chamber 19, the details of v;hich are shown in Fibre 2. The temperature of the solution for best irradiation results should be between 25 and 75 O C. Lower temperatures reqliuoe longer exposure to ultra-violet light.

Eighel temperatures reduce the yield of pure benzene. It may therefore be desirable to heat the solution slightly as it flows from column 1 to chamber 19 and a heat-exchanger 20 is provided for optional use. A ternperature of 45" C. is preferred, to prepare the solution for irradiation. Referring to Figure 2, the inner wall of chamber 19 is a glass tube 21 transparent to ultra-violet light, and open at both ends. The outer wail 2Z of glass or other non-meta.lic material has its ends sealed to tube 21 and is provided with an outlet 23. A fluorescent tube 24 emitting light of a wavelength from 30cud to 45000 angstrorns extends loosely through tube 21. Such light-tmimng tubes are available comnercially. The preferred wavelength is 3500 angstloms. Tne ditter- ence between the diameters of tube 21 and wall 22 may be from one to four inches, affording a layer of benzene solution of from one-half to two inches deep for penetration by ultra--ciolet light. The time of exposure should be from two to five minutes depend; ing on the, light intensity and temperature of the benzene. A series of chambers 19 may conveniently be arranged in cascade to afford the desired time of exposure. A connection 25 from the chamber 19 conducts to scrubber 16 any hydrogen chloride escaping from the solution during irradiation. A distinct color change occurs in the benzene as a result of irradiation. The radiation dissociates the chlorine into atomic form and it then readily combines with the contaminants remaining unchlorinated, such as the paraffins. The yellow coloration of the benzene is lost as a result of the disappearance of monocular chlorine and the effluent is water, white. Atomic chlorine also converts the carbon disulphide into carbon tetrachloride. The latter apparently polymerizes with other contaminants under the ultra-violet radiation, since it is not detectable in the final product, although its boiling point is near that of benzene After irradiation, the benzene is conducted through a connection 26 to the bottom of a packed column 27. Connection 26 is designed to allow several minutes, i.e., one to five and preferably t-wo, travel time between chamber 19 and column 27. This permits the final reactions initiated by the irradiation to proceed to compjetion. As stated above, all portions of the apparatus in which free chlorine is in contact with the benzene must be of ceramic material such as stoneware or glass, and kept free of metallic iron, in order to avoid the catalytic effect thereof producing chlorination of benzene. These portions include column 12, heat-exchanger 20, chamber 19 and all connections to, from and between them. Wash water is supplied to the top of column 27 at a temperature between 40 and 80" C. and preferably at about 600 C., from a heat-exchanger 28. The water should be alkaline, i.e., with

a pR of from 7 to 12 and preferably about 10. The volume ratio of benzene to water may vary from .5 to 4 and is preferably about 2. Water is maintained as the continuous phase in the bottom one-third of the height of the column and benzene as the continuous phase in the remainder of the height. As the benzene ascends through the continuous water phase, the hydrogen chloride is extracted. Some of the chlorinated contaminants in the benzene are hydrolyzed, forming a visible Aoc at the plane of phase separation between water and benzene. This hydrolysis occurs in the upper portion of the column in which the water is dispersed in the benzere phase. The floc and any hydrogen chloride formed during hydrolysis are extracted and carried down with the water descending the column. Waste water is taken off at the bottom of the column and washed benzene flows from the top into a settling tank 29 for gravity separation of any water carried over. The hydrolysis occurring in column 27 is essential because, otherwise, the hydrolyzable chlorinated contaminants left in the benzene, which are heat sensitive, will decompose on subsequent distillation to recover pure benzene, yielding hydrogen chloride as an impurity. This does not occur with proper hydrolysis of the chlorinated contaminants. The hydrolysis can be effected with water at room temperature but this requires a longer period of contact Benzene decanted from tank 29 is substantially water-free (less than 0.01% water) and is delivered by pump 30 to a fractional distillation column 31. The liquid benzene is vaporized in a boiler 32 connected to the bottom of the column and provided with heating means such as to steam coil 33. Benzene vapour is taken off overhead from the column and, after condensation in condenser 34 and cooling in atter-cooler 35, collects in tank 36, as pure product benzene which meets the rigid customers' specifications given above. Column 31 is of conventional construction and should provide about ten theoretical plates of fractionating power. Any chlorinated contaminants left in the benzene after it leaves the extraction column 27, by reason of their higher boiling points, collect as a residue in boiler 32 and may be removed periodically through a connection 37. The washed benzene contains organic chlorine compounds which will decompose in the presence of iron oxides or salts, leaving hydrogen chloride. It is thus imperative that the boiler 32 and the column 31 be of corrosionresistant metal such as stainless steel. The condenser 34 and after cooler 35 may safely be constructed of ordinary steel. Specific examples of the process described are given below. The raw benzene used had the following contaminants and characteristics: Thiophene 500 to llOU ppm. Carbon disulphide 2 to 5 ppm.

Olefins 0.03 to U.08n/o Solidification point 5.02 to 5.10 C, Boiling range 0.6 to 0.8 C. including 80.1 Refractive index nD less than 1,5ago at 20 C. The benzene fed from tank 1u to the column 12 was at 390 C. A ten-foot height of benzene was maintained above the diffuser 15 in the chlorine-addition column 12. In four different runs, amounts of 0.5, 0.75, 1.0 and 1.15% chlorine, respectively, were added, by weight of the benzene. The system was designed to allow two minutes travel time between diffuser 15 and chamber 19. No additional heat was supplied to the benzene chlorine-hydrogen chloride solution, the temperature of which was 35 C. leaving column 12., With a 40-watt fluorescent light as the source of ultra-violet radiation (3500 angstroms wave length), and a one-inch thick layer of benzene, three minutes travel time through the irradiation apparatus was maintained. This may reduce to 1.7 minutes by heating the benzene to 45" C. before irradiation. Travel time of one minute was allowed between chamber 19 and column 27 to complete reactions. Using a column 27 twenty feet high, the benzene was washed with 60D C. water of 9.9 PH at a 2:1 benzene-to-water volume ratio. In the bottom cne-third of this column the water was the continuous phase. In the top two-thirds of the column, benzene was the continuous phase. The washed benzene from the extractin tower was settled for two hours in tank 29. The settled benzene was fed to the fractionating still 31, and the refined benzene was ten off overhead. The yield of relined benzene obtained was 98.5 based on the benzene content of the original industrialgrade benzene. The water from the extraction column 27 contained about 7 grams per liter of hydrogen chloride. About 0.097 grams of hydrogen chloride per liter of benzene processed was collected in the vapor scrubber 16. The product benzene resulting from the foregoing examples had the following characteristics: - Per cent chlorine used 0.50 0.75 1.00 1.15 Thiophene, ppm. - - - - 0.0* 0.0 0.0 0.0 Carbon disulphide, ppm. - - - 0.0* 0.0 0.0 0.0 Olefins, % - - - - - N.D.** N.D. N.D. N.D. Solidification point, C. - - - 5.40 5.49 5.51 5.53 Boiling range, including 80.1 C. - - 0.5 0.4 0.4 0.4 Refractive Index n1) at 20 C. - - 1.5007 1.5009 1.5010 1.5011 *0.0: less than 0.1 **N.D.: none detected Chlorine may be added in liquid form to the benzene but the use of gaseous chlorine is preferred.

The advantages of our invention are readily apparent. In the first place, all the con taminants are rendered easily removable by treatment in one continuous operation with a single reagent. The process is simple and inexpensive and does not impose any necessary conditions not easily met. The amount of reagent used is small because a substantial economy results from retention of the hydrogen chloride formed in process, which also acts as a chlorinating agent. The outstanding advantages, however, are the substantially complete removal of contaminants and the very high yields of 98 or 99%, based on the amount of benzene present in the raw benzene being purified. What we claim is: - 1. A method of removing contaminants from benzene including the steps of bringing a controlled amount of free chlorine into contact with the benzene, promoting halogenation of the impurities in the benzene by irradiating the latter with ultra-violet light, subjecting the benzene to alkaline extraction with water, decanting the benzene from the water, and then distilling the benzene, whil maintaining the benzene free from contact with iron at least until substantially all the free chlorine has reacted, and maintaining the benzene after extraction free from contact with iron compounds until distilled, characterised in that the step of alkaline extraction includes introducing the chlorinated, irradiated benzene into the chamber of a multistagecontactor in one direction and introducing water thereinto in the other direction in a voluixie ratio of benzene to water of from 0.5 to 4, maintaintog the Pit of the water from 7 to 12 and Kle tem-veraturz from 40 to 80 C. rLherevy hydrolyzing the unstable chlorinated contaminants in the benzene into thermally stable compounds which remain as bottoms on distillation of the benzene, and maintaining a continuous water phase at the end of the chamber at which the benzene enters and a continuous benzene i phase at the end at which the water enters. 2. A method according to Claim 1, characterised by maintaining the piane of phase separation such that the water phase occupies about one-third the length of the chamber and the benzene phase the remainder. 3. A method according to Claim 1 or 2, characterised by erecting the extraction in a packed tower. 4. A method according to any of Claims 1 to 3, characterised by introducing the water in a volume ratio of benzene to water of about 2, maintaining the pH of the water at about 10 and the temperature at about 60 C. 5. A method of removing contaminants from benzene substantially as set forth and described hereinbefore.

* GB785660 (A)

Description: GB785660 (A) ? 1957-10-30

Fractionating solution containing more than one solute

Description of GB785660 (A)

COMPLETE SPECIFICATION Fractionating Solution containing more than One Solute We, FOOD MACHINERY AND CHEMICAL CORPORATION, a corporation organized and existing under the laws of the State of Dela- ware, United States of America, located at 1105 Coleman Street, San Jose, State of California, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a method of fractionating a solution containing more than one solute dissolved in a solvent common to said solutes so as to separate one solute from another, and more particularly to the separation by fractional crystallization or by interchange in crystal composition of components of such a solution in which the solutes have different degrees of solubility in a solvent common to said solutes and saturated with one or more of the solutes and wherein the solution is characterized by the solid and liquid phases tending to establish equilibrium with each other in said common solvent with the more soluble solute tending to predominate in the liquid phase and the less soluble solute tending to. predominate lin the solid phrase. With solutes having these particular charac- teristics, the present invention represents an entirely novel approach to their separation, the separation being continuous from a solution containing both solid and liquid phases of such solutes and the separation being la func- tion of the relative solubility of the solutes, and being effected by maintaining a concentration gradient of the solutes in the liquid phase, and hence a varying environment as to solubility which causes

an exchange of the less soluble component to the solid phase and the more soluble component to the liquid phase as the two phases slowly pass in countercurrent relation to each other through this varying environment. Examples of such solutions are potassium persulfate and ammonium petauifate in water or a sulfuric acid solution; an aqueous solution of potassium and ammonium sulfates; and an aqueous solution of barium and lead nitrates. The invention is applicable only to that type of solution which contains two or more solutes dissolved in a common solvent for said solutes .and which exhibits the characteris- tics of crystallizing out both solutes at the same time but in different proportion of one solute to the other in solid form than' the proportion simultaneously existent of such solutes in the liquid form. Such solutions have the characteristic ,that at a given temperature only one solid phase mixture of the solutes is in equilibrium with one liquid phase mixture of the said solutes in said 'common solvent. Each phase contains both solutes, that is, the solid phase consists of crystals of both solutes and the corresponding liquid phase in equilibrium therewith 'also consists of both solutes, but the proportion of the solutes in 'the solid phase is different from that fin the liquid phase. If the proportion of the solutes in either phase is changed from that which obtains when both the solid and liquid phases are in equilibrium with each other, there is a drive or tendency exerted which motivates a change in the proportion of the solutes in the other phase to restore equilibrium. In other words, when :a condition of equilibrium obtains, it may be considered that the solid phase represents an increasing concentration of one solute which automatically means an increasing concentration of the other solute in the liquid phase. As long as two or more solutes in a common solvent have relative proportions in their liquid and solid phases when in equilibrium with each other which are different, then there can be fractionation or separation of the two solutes in accordance with the present invention. Accordingly, one of the principal objects of the present invention is to provide a method for separating two for more solutes dissolved in a common solvent which have different equilibrium ratios in their solid and liquid phases. Another important object is to provide such a method by which the solutes are separated according .to their variable solubilities. Another object lis to provide such a process in which the fraotiona;tion icae take place under optimum controlled temperature conditions, tits being of value where the relative solubili- ties of the solutes become greater under either high or low temperatures as

compared with ambient temperatures. Fig. 1 is a vertical section through one form of apparatus suitable for carrying out the present invention for fruationation of a solution containing two solutes dissolved in a common solvent and in which the ratio of the solutes in the solid phase of such solution is different from the ratio of the solutes in the liquid phase when in equilibrium with said solid phase. Fig. 2 is a similar view of another form of apparatius. Fig. 3 is a fragmentary vertical section of the lower portion of the column shown in Fig. 1 but showing the same modified to include a heat exchange jacket. Fig. 4 is a fragmentary vertical section of the upper portion of the column shown in Fig. 1 but showing the same modified to include an internal wall scraper. In the practice of the present invention solid and liquid phases of two or more solutes having different degrees of solubility in a common solvent are established in the common solvent are established in lithe common solvent, the solution being characterized by tendency lof the two phases to establish equilibrium with each other with the more soluble solute tending to predominate in the liquid phase and the less soluble solute tending to predominate in the solid phase. Advantageously this can be done in a vertical tube or leg so that the solid phase, when having a greater specific gravity than the liquid phase, settles to the bottom .of the leg in the form of a loose mass in which the componen'ts or crystals of the solid phase are in closely associated relation and contact and support one 'another but which are readily disturbed to swirl about in the loose mass. The solid and liquid phases can be established by feeding one or both of the solutes in solid form or by feeding the solutes in the form of a highly concentrated or saturated solution and cooling the same to effect crystallization. With the solid phase settling in the liquid phase, the cooling is advantageously effected by having the upper part of the tube or leg in the form of a crystallizer the walls of which are chilled to promote crystallization. A feature of the invention resides in moving the solid and liquid phases in countercurrent relation with each other and in introducing solvent into that end of the loose mass toward which the solid phase is moving. Advantageously this is done by introducing the solvent into the lower end of the loose mass where the specific gravity of the solid phase is greater than that of the liquid phase and withdrawing the liquid phase from above the loose mass as one end product of the process. The solid phase, as the other end product of the process, is removed from that end of the loose mass adjacent the introduction of

'the solvent, this being the lower end of the loose musks where the solid phase settles in the liquid phase. The essential functioning of the process is in the exchange of the more soluble solute from the solid to the liquid phase and of the less soluble solute from the liquid to the solid phase continuously as the phases move in countercurrent contact with each other and with the solid phase progressively encountering a more and more dilute liquid. The discharging liquid phase is enriched with the more soluble solute and depleted in the less soluble solute and the discharging solid phase is enriched in the less soluble solute and depleted in the more soluble solute. These end products have readily been obtained in excess of 99% purities using various solute pairs, and over .a wide range of solute mixtures introduced as feed. In the apparatus shown in Fig. 1 for carrying out the invention with a solution wherein the solid phase is more dense than the liquid phase and wherein the solution to be fractionated is supplied as a feed liquor, the numeral 10 represents an elevated cylindrical crystallizer having in its upper part a liquid outlet line 11 through which the liquid phase, enriched in the more soluble solute and impover- ished in the less solube solute, is withdrawn. This crystallizer is shown as having a jacket or heat exchanger 12 provided with la supply line 13 and a return line 14 for a cooling medium The crystallizer 10 is shown as having a conical bottom 15 the lover reduced end of which connects with the upper end of -aver- tical tube or leg 16. The mixture to be fractionated is fed in the form of a liquid solution to the upper end of this tube or leg 16 through a feed line 18 and the common solvent for the two solutes is supplied to the lower end of this tube or leg 16 through a supply line 19. The tube or leg 16 is shown as having a conical bottom 20 terminating in a vertical outlet pipe 21 through which the crystals pass into a crystal separator indicated generally at 22. This crystal separator can be of any form and is conventionally illustrated as having an enlarged cylindrical body 23 provided with a dome 24 and a conical bottom 25, the latter terminating in a crystal outlet line 26 through which the solid phase, enriched in the less soluble solute and impoverished in the more soluble solute, is withdrawn. The dome 24 is shown as having a central upward extension 28 of greatly reduced cross sectional area as compared with the body of the crystal separator and the vertical outlet pipe 21 from the leg or tube 16 extends through this upward extension 218 and downwardly into the body of the crystal separator. A circular horizontal baffle 29 is shown as secured to the lower end of the outlet pipe 21 and as arranged with its perimeter in closely spaced relation with the body 23 so that the crystal laden

liquor is required to flow at low velocity through the crystal separator to give the crystals an opportunity to settle out. This flow is maintained by a pump 30 which withdraws liquid through a line 31 from the upward extension 28 of the crystal separator dome 24 and returns it to the conical bottom 20 of the leg or tube 16 through a line 32. With solutions having supersaturation characteristics there is a tendency for crystals to form on the cylindrical wall of the crystallizer 10. In such event the crystallizer would be provided with a scraper 33 as illustrated in Fig. 4. This scraper is conventionally shown as comprising a pair of helical blades 34 in engagement with this cylindrical wall and as connected by upper and lower cross bars 35 and 36. The upper cross bar 35 is shown as fast to a vertical shaft 38 extending through the top of the crystallizer and rotated in any suitable manner. Also with some solutions the relative solubility of the two solutes is influenced by temperature. For such solutions the lower part of the tube or leg 16 can be provided with a jacket or heat exchanger 40 which can be supplied with either a heating or a cooling medium from a line 41 and which leaves the jacket through an outlet line 42. In the event the materials to be rectified are in solid form, it would be unnecessary to provide a crystallizer and the apparatus would be modified as shown in Fig. 2 where the solids or crystals to be rectified are shown as introduced to the tube or leg 16a through an inclined tube 43 extending above the level of the liquid in this tube or leg land where this tube or leg is unprovided at its upper end with the crystallizer 10 the liquid outlet line 11 for the liquid phase enriched in the more soluble solute and impoverished in the less soluble solute being shown as connecting with the top wall 44 of the leg or tube 16a. Since in other respects the form of the invention shown in Fig. 2 is identical with that shown lin Fig. 1, the same reference numerals have been employed. The practice of the present invention will be particularly described in connection with the fractionation of ammonium persulfate and potassium persulfate which can be readily separated in a continuous process particularly since, in equilibrium, the ratio of potassium persulfate and ammonium persulfate in the liquid phase, to the potassium persulfate and ammonium persulfate in the solid phase, is about 1 to 10. The greater the differential in this ratio the easier the separation of the solutes and the closer the approach to unit the grreater the time of contact required between the solid and the liquid phases in effecting fractionation. The solution, preferably saturated or at high concentration, of these

solutes is supplied to the apparatus through the inlet line 18 or if supplied in solid form are supplied through the inlet tube 43. With potassium persulfate and ammonium persulfate the feed mixture is preferably at room temperature and the leg or tube 16 or 16a is not heated or cooled as the above equilibrium ratio of these solutes in the solid and liquid phases remains practically constant at all temperatures. The solvent employed is preferably water although aqueous sulfuric acid solutions have also been used. The proportion of potassium persulfate and ammonium' persulfane in the solids or liquid fed to the apparatus is not critical, a proportion of two parts of ammonium persulfate to one part of potassium persulfate having generally been employed. For maximum efficiency, but not critical to the operation of the process, the feed is preferably at that point in the height of the tube or leg 1'6 or 16a where the same ratio obtains as in the material being fed. That is, when fed as a liquid solution the solution is preferably supplied at that point along the tube or leg 16 where the same proportions of potassium persulfate and ammonium persulfate obtains in the liquid phase and when fed as a solid solution or mixture the solids are preferably supplied at that point along the tube or leg 116a where the same proportion of potassium persulfate and ammonium persulfate obtains in the solid phase. IIn the practice of the invention it is essen- tial that the solutes ;be present in both solid and liquid form and that the solid and liquid phases be in contact with each other for a sufficient length of time !and under a progressively changing concentration of the liquid phase to effect an interchange of the solutes from one phase to the other to enrich one phase in one solute and to deplete the other phase in that solute and hence enrich it in the other solute. To this end it is necessary to establish liquid and solid phases. If the solutes to be fractionated are fed in solid form to a solvent contained in the tube or leg 16a, as illustrated in Fig. 2, these phases are established without the necessity for crystallization, but if the solutes are fed as a liquid solution as illustrated in Fig. 1 the formation of crystals of the two solutes is required. To this end the jacket 12 of the crystallizer is preferably supplied with a cooling medium at a temperature sufficient to initiate crystallization, a temperature of from 5 to 10 C. in this illustration. At that temperature crystals of both the potassium and ammonium persulfates form and settle down the leg or tube 16, the crystals containing a large proportion of potassium persulfate as compared with ammonium persulfate and there being a .constant drive to establish a liquid.phase-soSid phase equilibrium ratio between the potassium and ammonium persulfates of about 1 to 10. The crystals settling from the -crystallizer 10 build up in the itube

or leg 116 as .a loose mass which is readily disturbed to swirl about When introduced in crystal form as in Fig. 2, the loose crystal mass likewise builds up in the tube or leg 16a. In either event .the crystals contained as a mass in the tube or leg is not in the form of a bed or packed mass of crystals but are loosely suspended and easily placed in motion and are more accurately described as a loose mass in which the crystals are supported by one another but are readily disturbed. It is desirable that this loose mass occupy substantially the full height of the tube or leg 16 since there is little interchange of solutes between the liquid and the solid phases while the crystals are settling and such interchange occurs in the loose mass. Accordingly to operate with a ;tube or leg of minimum height, substantially the full height must be eccupied .by the loose mass. With ammonium and potassium persulfates the height of the tube or leg 116 or 16a can be from three to four feet whereas with solutes such as barium and lead nitrates a leg or tube height of about nine feet is required. An essential feature of the invention is the introduction of solvent, which for fractionating ammonium .and potassium persulfates can be water or a sulfuric acid solution through the solvent inlet line 19. The rate of introduction of this solvent is determined Iby the cross sectional area of the fluidized mass, the greater this cross sectional area the greater the rate of inflow of the solvent at 19, it also being impottant, however, to avoid undue disturbance of the loose mass and particularly channelling uf this fluid mass in such manner as would permit any substantial quantity of solvent to rise without percolating through .the loose mass in intimate contact with all of the crystals thereof. The maximum rate of inflow lof the solvent, for a loose mass of given cross sectional area is also determined by the degree of fraction a- ;tion desired as well as the desired degree of dilution of the' liquid phase leaving the outlet 11. The rate of inflow of the solvent must be sufficient, however, to establish a gradient in the concentration of the solutes in the liquid phase by which the concentration of the solutes in the liquid phase increases toward the top of the loose mass contained within the leg or tube 116 or 16a. The crystals from the bottom of the fluidize mass in the leg or tube 16 or 16a are constantly being removed through the conical bottom 20 and outlet pipe 21 thereof. The rate of withdrawal of the crystals is dependent on the cross sectional area of the loose mass and by the necessity of maintaining this loose mass at the height required to provide the necessary time of contact between the solid and liquid phases to insure iotershange of the solutes from one phase to the other. With potassium and ammonium persulfates this time of contact is

in the order of one hour and twenty minutes. Accordingly it will be seen that the crystals of the loose mass in the ,tube or leg 16 or 16a slowly settle and are removed while fresh crystals are continuously being supplied to the top of this loose m!ass. It will further be seen that as each crystal set-ties it progressively encounters a more dilute solution due to the continuous supply of solvent from the solvent inlet line 19. In a mixture of potassium persulfate and ammonium persulfate the ammonium persulfate is more readily soluble, and tends to run to excess in the liquid form while conversely the potassium persulfate is less readily soluble and tends to run to excess in the solid form. With potassium and ammonium persulfates and mixtures of other solutes to which this invention relates, there is only one solid phase mixture which is in equilibrium with one liquid phase mixture and any change in the ratio of these persulfates in the liquid phase effects a corresponding change in the ratio of these persulfates in the solid phase to reestablish equilibrium. With these persulfates, as generally with mixtures of solutes to which the present invention is applicable, the ratios of the solutes in the solid and liquid phases change proportionally in response to a change in the ratio in the liquid phase so that the ratio of the solutes in the liquid phase to the solutes in the solid phase is such that the same solute predominates in the same phase throughout the system. For explanation, where <img class="EMIRef" id="026473784-00040001" /> represents concentrations of components A and B in the liquid phase in the system two solutes, A and B, and where <img class="EMIRef" id="026473784-00040002" /> represents the ratio of the s components A and B in the solid phase in contact with the liquid phase <img class="EMIRef" id="026473784-00040003" /> need not be 'a constant but must be greater than one throughout its range. If the ratio changes from more than one or less than one or lin other words, passes through one, then the limit of fractionation is at the eutetic when the ratio is one. When this equilibrium is disturbed, there is always a pressure to restore the equilibrium so if an excess of, ay, ammonium persulfate were added in the solid phase, the liquid would tend to dissolve some of the ammonium persulfate from the solid phase and precipitate some of the potassium persulfate from the liquid phase to reestablish equilibrium. Conversely, if solvent were added to the liquid phase of this equilibrium mixture, the added solvent tends to dissolve some of

the solid phase, and the pressure exerted 'to- ward maintaining equilibrium tends to dissolve some of the more soluble ammonium persulfate from the solid phase and to precipitate some of the less soluble potassium persulfate from the liquid phase in order to restore the equilibrium condition of having more aimmon- ium persuifate than potassium persulfate in the liquid phase and having more potassium persulfate than ammonium persulfate in the solid phase. In the loose mass of potassium and ammon ium persulfates contained in the leg or tube 16 or 16a, the descending crystals encounter a rising unsaturated liquid which tends to dissolve the crystals and the pressure exerted to wring the ratio of the solutes in each phase and the ratio of the solutes in the two phases into equilibrium tends to dissolve some 'of the more soluble ammonium persulfate from the solid phase and to precipitate some of the less soluble potassium persulfate from the liquid phase thereby to effect tan interchange of ammonium persulfate from the solid to the liquid phase and of potassium persulfate from the liquid to the solid phase. Before equilibrium can be restored, the descending crystals encounter a still more dilute rising liquid which again rends to dissolve the crystals and in which process the pressure exerted toward establishing equilibrium again tends to dissolve some of the more soluble ammonium persul fate from the solid phase and tot precipitate some iof the less soluble potassium persulfate from the liquid phase thereby to effect a further interchange of tammonium persulfate from the solid to the liquid phase and of potassium persulfate from the liquid to the solid phase. At no point do the solid and liquid phases actually reach a state of equilibrium, but exert a constant effort to reach this state. As a result of this extended contact between the descend ing loose mass of crystals and the rising column of liquid supplied by the introduction of solvent at the end of the loose mass opposite the introduction of crystals, the crystals be come progressively impoverished in the more soluble solute, namely, the ammonium persul phate, land enriched in the less soluble solute, namely the potassium

persulfate, as they approach the source of the solvent while the liquid becomes progressively impoverished in the less soluble solute, namely the potassium persulfate, and enriched in the more soluble solute, namely the ammonium persulfate, as it approaches the other end of the system from which the crystals are supplied. For each successive lower zone in the loose mass of crystals, the concentration of the crystals in the less soluble potassium persulfate becomes progressively greater, the crystals setting down to ;be depleted in the more soluble ammonium persulfate and the upwardly mov- ing contacting liquid phase receiving this ammonium persulfate and also precipitating a part of its less' soluble potassium persulfate It will be seen that at any one point in the loose mass contained in the leg or tube there are two feeds, one of solids setting from above, and one of liquor passing upwardly from below and that by virtue of the liquor being initially supplied as a solvent the interchange of the solutes between the phases is a function of the relative solubility of the solutes, the changing concentration of both solutes in the liquid phase and the pressure exerted by both phases to establish an equilibrium in which 'the solid phase is pre illustrated. To remove the solid phase as a scurry, liquid is recirculated by the pump 30, the return liquid being of the same composi tion as the removed liquid and hence not affecting the process. With screw feeders, filters or other types of separators it would also be desirable to return the liquid to the conical bottom 20 but such is merely incidenral to and is not lan essential part of the process. In the event that the solutes being fractiona red have supersaturation characteristics, and were fed as a liquid solution, they would tend to form a crystal coating on the chilled wall of the cryStallizer 10. Under such circum stances the scraper 33 shown in Fig. 4 would be used to continuously remove such coating. The use of such a scraper is not essential to the practice of the process. The invention is not essentially concerned with maintaining a temperature gradient and, as indicated, can be practiced with the ad mission of the solids to be rectified and the solvent at room temperature and without heat

ing or cooling any part of the apparatus, the cooling jacket 12 in the form of the inven tion shown in Figs. 1 and 4 being merely to cool the solution sufficiently low to induce crystallization. However where the relative solubility of the solutes is affected by tem perature, there would be an advantage, of course, in maintaining such temperature en vironment for .the loose mass as would provide an increased solubility of the one solute as compared with the other solute. For such solute either a heating or a cooling medium of appropriate value would be circulated though the jacket 40, Fig. 3, to maintain the optimum temperature "-of the fluidized mass which it surrounds. If the solubility curves of the two solutes spread with increase in temperature over room temperature it would be desirable to use a heating medium in the jacket 40 and 'if 'ther'e curves come together with rising temperature it would be desirable to use a cooling medium in'the jacket 40. It nvill also be .understood that the solutes to be fractionated are not necessarily intro duced to the tube or leg 116 or 16a as such but that - one can be in whole or part formed in the tube or leg. Thus assuming that there is available a solution containing a large amount of !ammonium persulfate and a small amount of p.otassium persulfate but that the desired end product is potassium persulfate, advantageously the leg ,or tube could be supplied with the solution and in addition a quantity of a potassium salt other than potassium persulfate. Such other potassium salt reacts with the ammonium persulfate to produce potassium persulfate, the desired end product, and which is separated from the remaining ammo- nium persulfate in the same manner as previously described. From the foregoing it will be seen that the present invention provides either continuous or periodic solid-liquid fractionation on a com mercial scale of flvo or more solutes in a com mon solvent where the solution and solvents have the characteristics discussed. It will be apparent that changes and modifications can be made which will nevertheless fall within the scope of the invention. For instance, mech

anical means such as a conveyer could be prod vided to insure the counterssow movement of the solid phase relative to the liquid phase instead of employing the difference in density between the solid and liquid phases for this purpose. By the term " fractiona,ting " as used in the accompanying claims is meant the progressive interchange of solutes from the liquid to the solid Phase and vice versa, regardless of whether this is done by the fractionation of a feed liquid as illustrated in Fig. 1, or by stripping from a solid feed as shown in Fig. 2. What we claim is: - 1. A method of fractionating two or more solutes from a solution which contains the solutes in a common solvent characterized by establishing solid and liquid phases of the solutes in a common solvent medium, the solid and liquid phases being moved countercurrent to each other, the common solvent being intro duced into that end of the medium toward which the solid phase tends to move, to pro vide .a concentration gradient in the liquid phase of the solutes with respect to the com mon solvent, removing the solid phase from the body adjacent the place of introduction of the solvent and removing the liquid phase from the end of the medium opposite that from which the solid phase is removed. 2. A method in which potassium persulfate and ammonium persulfate are introduced into a common solvent medium according to Claim 1 the solid phase which is removed being en riched in potassium persulfate and depleted in ammonium persulfate by the countercurrent movement of the phases, the removed liquid phase being enriched in ammonium persulfate and depleted in potassium persulfate by the countercurrent movement of the phases. 3. A method according to claim 1 our 2 in - which the solutes are introduced into the body at a point intermediate the ends ;thereof.

4. A method according to Qaim 3 in which the end of the body opposite to the intro ductory end of the solvent is cooled to establish solid and liquid phases therein, gather ing the components of the solid phase with the components in closely associated relation with one another, moving the liquid phase through the closely associated solid phase in countercurrent relation with the solid phase and toward the opposite end of the body. 5. A method according to any of the preceding claims in which a potassium salt other than potassium persulfate is introduced intermediate the ends of the body to react with

* GB785661 (A)

Description: GB785661 (A) ? 1957-10-30

Wire printer

Description of GB785661 (A)

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PATENT SPECIFICATION NW o, 7859,661 C Date of Application and filing Complete Specification: Oct 10, 1955. No 28799/ 55.

Application made in United States of America on Oct 13, 1954. Complete Specification Published: Oct 30, 1957. Index at acceptance:-Class 100 ( 4), C 20 (B 9: G 2 BX: Y 4), C 27 L. International Classification:-B 41 j. COMPLETE SPECIFICATION Wire Printer We, INTERNATIONAL BUSINESS MACHINES CORPORATION, a Corporation organised and existing under the laws of the State of New York, United States of America, of 590 Madison Avenue, New York 22, New York, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement - This invention relates to wire printers wherein the ends of a group of print wires are moved against recording material to form each character impression. Wire printing mechanisms of this type are disclosed in our Specification No 763,407. In the printer disclosed therein, the print ends of a group of preset print wires, mounted in curved flexible tubes, are moved against a recording material backed up by a platen by a print head to which the ends of the curved tubes are affixed adjacent the protruding print ends Such a wire printing mechanism rapidly prints single characters of high uniformity and clarity. An object of this invention is to provide an economical apparatus which can rapidly print large numbers of characters of high uniformity and clarity. According to the invention, we provide a wire printer having a plurality of wire printing mechanisms each comprising a plurality of print wires gathered at one end into a group at a print head and movable endwise relative to a platen to effect a printing stroke, including means for simultaneously moving the respective print heads laterally of the platen to enable successive printings in successive character positions. The print heads may be operated together to print a number of characters simultaneously, then adjusted laterally in small increments equal to the spacing between adjacent characters, with a printing stroke after each increment Through a series of such adjustlPrice 3 s 6 d l ments and printing strokes, a complete line of printing is rapidly effected by a small, economical number of wire printing mechanisms Any well known way may be uti 50 lised to present sequentially the different characters to each wire printing mechanism. Preferably the print wires of each mechanism are guided in flexible tubes extending in sweeping curves to the corresponding 55 print head to which the tubes are attached.

The print wires of each mechanism may be arranged to be preset by wire setting mechanisms mounted in a bank in the same order that the corresponding wire groups are dis 60 posed opposite the platen Said wire setting mechanisms may include code means adjustable to various settings, certain of said code means being interconnected for simultaneous adjustment so that printing of cer 65 tain characters is duplicated. The groups of print wires may be disposed in several rows to effect simultaneous multiline printing. Various other features of the invention 70 will be apparent from the following description of preferred embodiments thereof, referring to the accompanying drawings. In the drawings: Fig 1 is a diagrammatic view showing one 75 embodiment of the invention. Fig 2 is a schematic detail view of apparatus for operating the embodiment of Fig 1. Fig 3 is a subcycle chart depicting the 80 timing of the wire printing mechanism elements of the Fig 1 and 2 embodiment. Fig 4 is a chart depicting the main cycle of the apparatus. Fig 5 is a diagrammatic view showing an 85 embodiment of the invention as employed for multi-line address printing. Referring more particularly to Fig 1, the invention is shown therein as being embodied for use in an interpreter In such an inter 90 preter, data recorded as perforations on a card is sensed and thereafter printed on the 9 d: / i l same card for easy reading Conventionally, the printing is effected in a line along a long edge of the card In addition, other data such as an identifying number is often printed in bold form across the end of the card for easy recognition when the card resides upright in a vertical slot. The wire printing mechanisms are shown as having their wire setting mechanisms, generally indicated by the numeral 10, arranged in a bank Each wire setting mechanism is shown as being supported upon a base 12 which is provided with a guide member 14 through which the print wires 16 extend and to which the flexible tubes 18 for guiding the individual print wires are attached The print wires extend from the guide member and into a housing 20 carried by a reciprocable common support element or bail 22 The housing 20 mounts the vertically extending code rod 24, which is adjustable up and down through a collet 26 fixed to it by a forked lever 28 and rotatable to different positions through a gear 30 fixed to it by a rack 32 After the code rod 24 is positioned, the housing 20 is reciprocated so that the code rod moves against the end of the pre-aligned print wires to preset them by selective longitudinal displacement The pre-aligning is effected by a bail 34 slotted to receive the print wires and located

between the guide member 14 and the housing 20 where it acts upon inertia slugs 36 affixed to the respective print wires. From the wire set up mechanism the guide tubes 18 and encompased print wires 16 of each wire printing mechanism extend in broad sweeping curves to where they are gathered together to form a cable The cable terminates at its upper end in print head 38 to which the respective tubes are rigidly attached The print ends 16 a of the print wires, however, extend out of the tubes and beyond the uppper end of the print head as well as above the upper edge of a bail 40 to which the print heads are rigidly attached. The bail is formed of a pair of spaced vertical plates 40 a and 40 b rigidly interconnected by spacer bars 42 and between which the print heads 38 are mounted It is supported so that normally the print ends 16 a of the print wires are in spaced relationship to a platen-backed recording material, such as the card 44 shown, by a pair of synchronously rotatable single-lobed cams 46 These cams are operated in synchronism with the wire set-up mechanisms 10 and so that the lobes on the cams move against the bail after the print wires have been preset to impart a printing stroke to the print head. The lateral adjustment of the bail relative to the platen to effect printing in the card spaces between the normal positions of the print head is effected through an arm 48 a carried by a link 48 The upperly extending portion of the arm 48 a is received between the plates of the bail 40 and carries a forwardly and rearwardly extending stud 50. This stud is received in aligned verticallyextending slots 52 formed in the bail mem 70 ber plates 40 a and 40 b One end of the link 48 is attached to the upstanding arm of a bell crank 49 (Fig 2) The other or horizontal arm of the bell crank is provided with a roller 49 b which rides on the surface of a 75 continuously rotatable cam 51 operative to rotate the bell crank through small increments enabling printing in adjacent positions. It should be observed that the vertical slots 52 in the bail plates permit a printing stroke 80 to take place without effecting the aligned relationship to which the bail has been adjusted. Duplicate printing is shown as being advantageously utilised for effecting end 85 printing in bold form upon a card For example, in employee attendance cards the employee number may be recorded along with other data in a line along the long edge of the card and, in addition, along the end of 90 the card where it may be readily recognised in an attendance rack Duplicate printing of the employee number is obtained by providing a common set-up mechanism for code rods 24 of respective print mechanisms Thus 95 the levers 28 for operating on the collets 26 on the respective code rods may be interconnected by an element 54 for uniform up and down movement while

the racks 32 meshing with the gears 30 on the upper ends 100 of the respective code rods may be interconnected by an element 56 for uniform rotational movement Only one positioning mechanism would be needed for these racks and levers Thus, the same setting would be 105 applied at all times to the print wires of the respective wire printing mechanisms. The print head of the wire printing mechanism for effecting end printing may be supported by a separate bail 58, though it may 110 be supported by a bail formed integral with the bail 40 As shown, the bail 58 is provided with an aperture in which an enlarged print head 38 a is mounted The bail may rest upon a single-lobed cam 60 which is rotat 115 able synchronously with the cams 46 for the bail 40 A bell crank 62 (Fig 2) has the end of one lever formed with ball 62 a which is received in a slot 64 formed in the bail 58. The other lever of the bell crank is con 120 nected by a link 66 to the bell crank 49. Thus, adjustment of this bell crank 62 is effected simultaneously with the adjustment of the link 48, and it can be seen that the bail 58 would thus be operated in the same 125 fashion as the bail 40 to effect serial printing. The operation of the arrangement shown in Fig 1 may be effected as follows: In an interpreter, a number of spaced columns of 130 785,661 785,661 3 index point positions on the card 44 may be sensed simultaneously by columns of E brushes B (Fig 2) on a shiftable brush plate i BP and electrically connected to the adding t linkage latch tripping magnets such as A, B, C, D, E, and F of the respective wire setting mechanisms Circuits from a contact plate CP underlying the card and also constituting 1 the platen are completed through magnets for corresponding card perforations at the j start of each printing of subeycle by the closing of cam contacts Cl This may be completed by 45 of subcycle time (Fig 3) The code rod set-up bails (not shown) may then be operated upon the respective tripped magnet latches to impart rotational and translational displacement to the respective code rods 24 as in the above identified patent specification Code rod movement may be completed by 90 of subcycle time; at this time the wire setting bail 22 is operated to move the housings 20 so that the code rods move against the print wires 16 of the respective wire printing mechanisms The print wires to be preset may be displaced by 1350, after which the housings 20 restore. The print heads then undergo a printing stroke from 1571 ' to 2021 subcycle time. Thereafter the code rods and their set-up bails may be restored At 2250, the bails 34 move toward the housings 20 to engage the inertia slugs 36 of the preset print wires and fully restore them to realigned

condition At 2700 of subcycle time a stepped cam 51, which completes one revolution in each main cycle, begins to move the follower roller 49 b from the first to the second step. This operates through the bell crank 49 and the links 48 and 66 and bell crank 62 so that the print heads 38 and 38 a are adjusted to the next adjacent character positions Concurrently therewith, the cam 51 adjusts the brush plate BP so that the brushes B will sense the next adjacent columns The following printing or subcycle would automatically ensue. If the print heads are spaced four character positions apart so that initially only the 1, 5, 9, etc, character positions are printed, it can be seen that each main cycle must comprise four printing cycles and the cam 51 must have four steps In addition, the main cycle is lengthened to include one additional subcycle to accomplish ejection of the old card and the feeding of a new one In this manner a large number of cards can be rapidly interpreted. In Fig 5 there is disclosed a four-line address label printing arrangement In such an arrangement the labels are preferably joined end to end to form a tape 67, and this tape would be moved in increments to present successive labels to the printing mechanism. Any suitable mechanism (not shown) may be employed to effect such tape feeding. The wire set-up mechanisms for the wire printing mechanisms employed are mounted n a bank as in Fig 1 However, in between he wire set-up mechanisms for successive print heads on the same line may be inter 70 spersed the wire setting mechanisms for the vire printing mechanisms for printing underlying characters on the other lines of the address Thus, in a four-line address printing machine, the wire setting mechanism for the 75 print heads for printing underlying characters on the second, third, and fourth lines would be mounted in that order alongside the wire setting mechanism for the print head in the first line With such arrangement the 80 print wire cables converge to the cables for the respective print heads in successive orders so as to eliminate any interference therebetween. The print heads 38 for a four-line address 85 printer may be mounted in a five-plate bail 68-those print heads for a given line being mounted between the same pair of plates while those for the underlying characters are mounted directly underneath between adja 90 cent plates The bail may be supported upon a pair of cams 70 to effect printing strokes. A bell crank 72 for operating this bail may consist of two upstanding arms 72 a and 72 b which are interconnected by a pin 74 slid 95 ably received in vertically extending openings 76 formed in each of the bail plates.

Printing strokes may be effected by the cams in the usual way without disturbing the setting of the bail while the bell crank may 100 be adjusted to each of the character positions between the adjacent print heads. The operation of the mechanism described in Fig 5 is substantially like that for the mechanism disclosed 'in Fig 1 Instead of 105 feeding a new card to the print heads after each complete printing, the tape 67 is adjusted endwise to dispose a new label opposite the print heads As before, data would be serially presented to the various wire 110 printing mechanisms from whatever constituted the source of the data For example, such addresses could be obtained from successive record cards or from magnetic tapes or drums 115 While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitu 120 tions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art, without departing from the scope of the invention It is the intention, therefore, to be 125 limited only as indicated by the scope of the following claims.

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* GB785662 (A)

Description: GB785662 (A) ? 1957-10-30

Improvements in valve actuator assemblies for internal combustion engines

Description of GB785662 (A)

PATENT SPECIFICATION 785,662 Date of Application and filing Complete Specification Oct 20 '955.

No 30000/55. Application made in United States of America on Nov 9, 1954. Complete Specification Published Oct 30, 1957. Index at Acceptance: -Class 135, VD 14 A. International Classification: -FO 6 k. COMPLETE SPECIFICATION Improvements in Valve Actuator Assemblies for Internal Combustion Engines We, GENERAL MOTORS CORPORATION, a company incorporated under the laws of the State of Delaware in the United States of America, of Grand Boulevard, in the City of Detroit, State of Michigan, in the United States of America (Assignees of JERAR ANDON, Bo R Is JOHN MITCHELL and RALPH ERIC Scnw IND) do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be nerformed to be particularly described in and by the following statement: - This invention relates to actuator assemblies for poppet valves of internal combustion is engines. In internal combustion engines of the overhead valve type for, example in which the valves are actuated in the valve opening direction by rockers and returned to the closed position after each orening stroke by springs reacting against a fixed part of the engine, an objectionable valve "squawk" noise is frequently experienced during engine operation. This valve " squawk " is to be distinguished from the so-called " clicking " noise resulting from the taking up of the valve lash or operating clearances in the valve actuator mechanism, and which is avoidable through the use of self-adjusting valve lifters Valve " squawk ", on the other hand, is caused by sticking of the valve stems in their guides, and although this sticking condition might appear to be easily avoidable by better lubrication of the stem in the guide, such an expedient would result in the additional lubricant being drawn into the engine combustion chamber where it would burn and create a smoky exhaust, as well as increasing the engine oil consumption rate Also, in the case of exhaust valves a minimum of lubrication is preferred because their high operating temperatures tend to cause the oil to burn on the sliding surfaces of the valve stem and guide. By the invention such sticking of the valve stems and the consequent " squawk " noise are eliminated by isolati the valve stem from lateral forces tending to act on it during reciprocation Such lateral thrust forces are produced by coil return springs which, because they are out of square or for other reasons, 50 do not move coaxially with the valve, and by the horizontal component of the valve rocker movement as it oscillates about its axis which is necessarily spaced a considerable distance to one side of the valve stem 55 The scope of

the invention is indicated by the appended claims; and how it can be carried into effect is hereinafter particularly described with reference to the accompanying drawings in which: 60 Fig 1 is a part sectional elevation of a rortion of an internal combustion engine having a poppet valve actuator mechanism according to the invention; Fig 2 is an enlarged detail of Fig 1 show 65 ing in section the parts of the valve spring retainer and rocker thrust transmitter means, Figs 3, 5 and 6 are views, similar to Fig. 2 of modified embodiments of the invention; and 70 Fig 4 is a section on line 4-4 of Fin 3. Referring first to Figs 1 and 2, there is shown an internal combustion engine 1 havring a poppet valve 2 reciprocably mounted in the engine cylinder head 19 and one rated by 75 valve gear including a rocker 3, push rod 4. tappet 5 and engine driven cam 6 all of conventional design The valve 2 has a stem 7 slidably guided by a bushing 8 fixed in the cylinder head 19, and biasing the valve to its 80 closed position (shown) is a coil return spring 9 embracing the valve stem and reacting at one end against the cylinder head. A device 10 (Fig 1) forms a connection between the other end of the spring 9, the 85 valve stem 7 and the valve end of the rocker 3, and, as shown in Fig 2, serves both to isolate the valve stem 7 fromn any movements laterally thereof by the rocker 3 or spring 9 A and to relieve the valve stem substantially of 90 all forces tending to restrain its axial rotation during reciprocation, and particularly during 785,662 the valve opening stroke As shown in Fig 2 _ a washer 11 embraces the valve stem and provides a seat for the upper end of the spring 9 _ the size of the opening 12 in this washer being such that its radial clearance with the periphery of the stem 7 will accommodate the horizontal component of movement of the valve driving surface 13 of the rocker during its oscillatory movement about the rocker bearing 14 (Fig 1) Seated on the washer 11 in a counterbore 15 thereof is a dished cap member 16 which overlies the end face 17 of the valve stem 7, the latter having a device to abut the washer 11 and transmit the valve spring thrust from the washer 11 to the stem 7 during the valve closing movement which follows each lift stroke of the cam 6 This abutment device is removable from the stem and includes the conventional split wedge section locks 18 and a tapered keeper sleeve 20 which secures the locks 18 on the stem 7, such wedging engagement being assisted bir radially extending tongue portions 21 on the locks 18 which are received in an annular groove 2 ? formed in the periphery of the stem and terminating in a shoulder 23 forming a positive stop for the tongue portions 21. Outwardly of the opening 12 the washer 11 is flanged upwardly to form

side walls 24 of an enclosure 25 about the sleeve 20 and the cap member 16, the latter forming a continuation of the enclosure 25 about the wall and end face 17 of the valve stem 7 Since the abutment means including the locks 18 and sleeve 20 are self-retained on the stem 7, no lateral support therefor is required or provided by either the washer 11 or the cap member 16 and ample clearance can be provided between the washer walls 24 and the sleeve 20, and between the cap member 16 and the sleeve 20, to accommodate the full lateral movement of the washer and cap member with the rocker surface 13 The lower end face 26 of the sleeve 20 extends sufficiently laterally of the stem to ensure that it will always overlie the opposing surface 27 of the washer 11 throughout the range of lateral movements of the washer relative to the stem 7 A predetermined clearance 28 (of the order of 0 002 inches) is provided between the cap member 16 and the valve stem end face 17 w'hen the valve is closed and the sleeve face 26 arid washer surface 27 are in abutment with each other, this clearance 28 being taken up during the initial portion of each valve opening movement of the rocker 3 before any positive driving movement is imparted to the valve by the rocker As a result, the valve stem 7 is relieved of its spring pressure during each valve opening stroke, and after the clearance 28 is taken up the valve merely follows the downward movement of the cap member 16, without any lateral forces being transmitted to the stem 7 other than that incident to frictional engagement of the slidably engageable thrust surfaces of the cap member 16 and the stem end face 17 As a result, the stem 7 is substantially isolated from all forces acting laterally thereof and tending to cause its binding and sticking in the valve guide 8 and is also relieved of 70 substantially all frictional forces tending to restrain its axial rotation during valve opening On the return stroke, the washer acts under the thrust of the spring against the sleeve 20 and the locks 21 to move the valve to 75 its closed position, while the cap member 16 operates against the surface 13 of the rocker in returning the latter to its valve closed position. The embodiment shown in Figs 3 and 4 20 operates in the same manner as that previously described and differs in structure therefrom essentially only in the washer abutment device and the cap member The abutment device for this form consists simply of a U-shaped kev 85 with a tapered throat 122 whose internal periphery 121 has a a close fit with the bottom of the stem groove 22 and extends circumferentially thereof somewhat more than 1800 The key 120 is thereby self-retained 90 laterally of the stem, and its removal and installation on the stem 7 is effected b' s's 7 expanding the throat with a suitable tool (not shown) to permit the grooved portion 22 of the stem to pass through the throat For greater 95 siinplicit r of

manufacture the cat member is made as a flat disk 116 but the washer 111 does not differ significantly in design from the previously described washer 11. Fig 5 shows twvo further refinements in 100 construction which simplify the installation and removal of a U-shaped valve keeper 120. and reduce the manufacturing cost of a washer 211 In this embodiment a valve stem 207 has the bottom of its groove 22 relieved annularly 105 below the keeper 120, as shown at 222, whereby the keeper 120 can be inserted and removed over the relieved portion 222 of the groove, and when positioned against the shoulder 23 is secured against lateral displacement t; 110 restricted throat of the keeper Instead of the cap member 116 being directly seated on the bottom of the counterbore 15 it rests on a bushing 240 which, in turn, seats on the washer thrust surface 27 It will be noted that 115 ample radial clearance is provided betreen the bushing 240 and the keeper 120 to accommodate full lateral movement of the washer and cap member with rocker 3. In the embodiment shown in Fig 6 the 120 valve stem has a groove 322 which terminates at the valve head end with a shoulder 341 which cooperates with the upper shoulder 23 to lock the keeper 120 positively against movement in either direction longitudinally of 125 the valve stem Also in this form, the predetermined clearance taken up between the cap member and the valve stem during the initial valve opening stroke is provided at 342 between a cap member 316 and the keeper 120 130 of the washer engageable by said abutment or 55 keeper that a predetermined axial clearance is maintained between said valve stem and member when the washer engages said abutment or keeper. 6 An actuator assembly for a poppet valve 60 for an internal combustion engine, comprising a valve spring retaining washer having its axial opening of a size accommodating full lateral movement of the washer by the valve rocker relative to the valve, a surface on said washer 65 facing in one axial direction thereof for seating the valve spring, said washer having a counterbore facing in the opposite axial direction and forming a shoulder disposed radially inward of said surface, a keeper within said 70 counterbore said counterbore being of a diameter accommodating full lateral movement of the washer relative to the keeper, and said keeper having means adapted to interengage and positively transmit thrust to the valve in 75 said opposite axial direction and a surface facing in said one axial direction and overlying said shoulder in all operative positions of the washer laterally of the valve, and a member seated on said washer surface and forming a 80 closure for the open end of said counterbore, said member having a valve engageable surface so spaced axiallv of said shoulder that a predetermined axial clearance exists between said member and the valve when said keeper sur 85 face is in abutment with the

shoulder. 7 An actuator assembly for a poppet valve of an internal combustion engine, substantially as hereinbefore particularly described and as shown in Figs 1 and 2 of the accompanying 90 drawings. 8 An actuator assembly for a poppet valve of an internal combustion engine substantially as hereinbefore particularly described and as shown in Figs 3 and 4 of the accompanying 95 drawings. 9 An actuator assembly for a poppet valve of an internal combustion engine, substantially as hereinbefore particularly described and as shown in Fig 5 of the accompanying draw 100 ings. An actuator assembly for a poppet valve of an internal combustion engine, substantially as hereinbefore particularly described and as shown in Fig 6 of the accompanying draw 105 ings. E WILLIAMSON, Chartered Patent Agent. The operation is otherwise the same as that of the previously described embodiments shown in Figs 2, 3 and 5, and has some disadvantage with respect to those in that the thrust force acting between the cap member and keeper are at a larger radius from the valve stem and hence less able to isolate the stem from the lateral component of rocker movement and friction tending to restrain valve rotation Some advantage however, is gained in reducing the requirements for maintaining close manufacturing tolerance since the width of the groove 322 and the thickness of the keeper 120 are the only dimensions requiring close control Maintenance of the clearance 342 can be periodically adjusted as necessary by varying the relative axial positions of the cap member and washer at their threaded connection 343 Wrench flats 344 are provided on the upper end of the cap member 316 for this purpose.

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