* GB785533 (A)

Description: GB785533 (A) ? 1957-10-30

A method and apparatus for improving the physical properties of metalmembers

Description of GB785533 (A)

PATENT SPECIFICATION 785,533 Date of Application and filing Complete Specification Jan 18, 1954. No 1373/54. Application made in Canada on June II, 1953. 9 9 / Complete Specification Published Oct30, 1957. Index at Acceptance:-Classes 83 ( 2), A( 116: 163 A); and 83 ( 4), M( 2: 3 C: 9 N: 15 A: 19 D), V 2, X. International Classification: -B 21 b B 23 p F 06 b. COMPLETE SPECIFICATION A method and Apparatus for improving the'Physical Properties of Metal Members I, TADEUSZ WLADYSLAW WLODEK of 297 Fifth Avenue, Ottawa, Ontario, Canada, of Canadian nationality, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described by the following statement:- This invention relates to a method of improving the physical properties of metal members; tneir welds, joints, fillets, threads, metallurgical notches, and the like; and to different types of apparatus for carrying out the method. It is well known that the physical or mechanical properties of metal constituting preformed elements may be strengthened and improved by various treatments such as shot-peening, regular cold rolling, carburizing or nitriding of steel, induction hardening, heat treatment, and others The fields in which the various methods have been employed depend on the nature of the metal to be treated, the shape of the element, and the economy of the treatment A common method of improving the surface properties of steel axles or the like is to roll the entire surface of the axle under fairly high pressure Such

opeartion affords a small increase in the physical properties of the metal constituting the axle, and, because of longer time required is a relatively costly operation. It has now been discovered that surprisingly improved properties are produced in metals constituting structural elements, rails, plates, bars, rods, tubes, drill pipes drill pipe connectors-tool joints, thin airplane sheeting and channels and the like, of simple and complicated form, their welds, joints, fillets, threads, etc, on like elements which are disclosed in the Specification of our co-pending Application No 34358 of 1955 (Serial No 785,534) by creating within the material locked-in residual stresses which work against the stresses imposed upon the structural element as it is used, thus increasing the useful life of the element, or the load which it is capable of carrying These locked-in residual stresses are created by different types of apparatus devellPrice 3 an 6 D C I i; oped for the purpose of applying pressure to portions of the material to give it permanent or so-called plastic deformation and leaving 51 adjacent portions of the material in its normal or elastic form It appears that the alternate juxtaposition of these xegions jof plastically deformed material with those in the normal elastic form or practically normal elastic form 5 results in an interlocking of the internal stresses in the treated areas of the material to enable the structural element to withstand heavier loads or have a longer useful life. This new treatment is based on the creation 6 of locked-in residual stresses through the introduction of mainly plastically deformed regions in alternate juxtaposition with regions substantially plastically deformed In general, juxtaposition of regions plastically deformed 6 with regions of lesser plastic deformation, both regions being arranged in a regular or irregular pattern is the topic of this treatment The transition between these two regions may be gradual or abrupt, and the built-in residual -7 stresses are substantially perpendicular to the direction of plastically deformed regions, i e. direction of pattern It should be also emphasized that impression of grooves and depressions provides, through so-called mutual interlock 7 ing phenomena, a controllable mechanism of plastic deformation of treated surfaces, resulting in greatly improved physical qualities of material treated by this invention. It is an object of this invention to provide a method for greatly increasing the physical properties of metallic elements by rolling or otherwise impressing grooves or depressions of various patterns and shapes on the surface of such elements and an effective apparatus for carrying out this method. It is a particular object of this invention to provide an apparatus for improving the physical properties, particularly resistance to

fatigue, of a drill rod, drill rod bit attachment, drill pipe, drill bits, shafts and similar elements, and connectors of all these elements, by rolling on or impressing on the outside or on the inside or on both surfaces a plurality of shal'), 11 r. a? is low grooves or depressions, or both, on the engaging end of these elements, threaded connections, and, if desired, on other parts thereof. The invention will be described with reference to the accompanying drawings, in which Figure 1 is an illustration of a structural element showing sections of plastically deformed metal, each in juxtaposed relation to a section of metal substantially in its normal elastic form, as produced by the invention. Figure 2 is a diagrammatic illustration of one pattern of treatment of a metal bar as produced by my apparatus. Figures 3, 4, 5, 6 and 8 are diagrammatic views showing various examples of patterns of treatment, as produced by the apparatus. Figure 7 is a section view along the line 7-7 of the pattern shown in Figure 6, as produced by the apparatus. Figures 9, 10 and 11 are enlarged views in section of a piece of metal showing various examples of shapes of grooves and depressions, as produced by the apparatus. Figures 12, 13, and 13 a, b, c, d, are elevation views partly in section of various forms of apparatus for carrying out the method of the invention. Figure 12 a, b, c, d, e, f, g, hi, and i are elevation of different examples of rollers used in our apparatus. Figure 14 is a diagrammatic elevation view, partly in section, illustrating another form of apparatus for carrying out the invention. Figure 15 is a side elevation view, partly in section, of another form of apparatus. Figure 16 is a front elevation view of the apparatus shown in Figure 15. Figure 17 is a section view taken on the line 17-17 of Figure 15. Figure 18 is a section of a drill rod bit attachment with attached bit treated in accordance with the invention and in our apparatus. Figure 19 is a section view along the line 19-19 of Figure 18. Figure 20 is a blown up side elevation view of a drill rod, with conical drill rod attachment, thimble and bit, treated in our apparatus. Figure 21 is a cross section view of the drill rod taken on the line 21-21 of Figure 20; and Figure 22 is an enlarged sectional view of a portion of a drill rod bit attachment assembly Figure 22 a is a view of a threaded drill rod attachment, treated in our apparatus. In accordance with the invention the physical properties, specially

fatigue, corrosion fatigue, stress corrosion static and dynamic strength; resistance against fretting, wear and erosion of structural metal members are greatly improved by impressing shallow hollows, grooves or depressions at spaced intervals thereon, said intervals being so spaced as to leave between adjacent pairs of grooves or depressions or the like a portion of metal which has not been directly subjected to deformation. The effect produced by the method of the invention is characterized by the magnitude and direction of the locking residual stresses which are produced in the metal of the struc 70 tural element under treatment by the different combinations of: force used, direction of the applied force, patterns and their sequence, and the depth, shape and cross-section of the depressions and grooves In order to increase 75 the effect of our treatment the structural element, if required, could be treated while under stress The residual stresses thus creatjd are directed against the working stresses imposed on the structural element, with the result that 80 the element has longer useful life and greater capacity to resist the strain caused by the load imposed on the element. The hollows, grooves or depressions may be of any desired shape and may be applied by 85 any desired means to various types of metal structural members, their welds and joints, fillets, threads, metallurgical notches, and the like, in a variety of patterns The grooves or depressions may be impressed by rolling, heli 90 cal rolling, extruding, pressing, stamping, hammering, squeezing, drawing and twisting or the like, depending upon the character or the form of the memoer to be treated In the case of tubular metal members, pressure 95 vessels, cylinders and other hollow members, the grooves or depressions may be impressed on the outer or inner surface or both; these impressed grooves and crests, the surface of which may be either machined or not, may 100 serve also as guides for other moving elements or serve as a -grip" for paint, plastic and other surface protective material It will be appreciated that the crests and troughs of the depressions or grooves may be subjected to 105 any subsequent treatment such as machining, grinding, or the like Furthermore, the grooves may be so designed as to provide guides for elements arranged to move along the surface thereof For example, the rifling of a gun bar 110 rel may be produced by the method of the present invention The grooves so formed partly i e after pre-machining, or completely by this method not only greatly improve the physical properties of the gun barrel, through 115 the "auto-frettage-rolling" described in my applications, but at the same time provide the necessary rifling It will be obvious that there are many other practical adaptations of the present invention 120 In the enlarged view of Figure 1 there is

illustrated pictorially the effect of forming on the surface of a metal member 1 valleys or grooves 2 leaving crests or untreated portions 3 As a result of the pressure applied to make 125 the grooves or depressions 2 there is produced in the areas A metal of substantially all plastic or permanent deformation whereas the metal of areas B remains substantially in its original elastic form The mutual interlocking stresses 130 785,533 or Figure 5, applied on the outside, inside or both surfaces where the pitch is small, are 60 recommended Performed measurements of the ratio of longitudinal and transverse locked-in compression stresses, gave for this pattern a factor larger than one This results in the reduction of working stresses in bending, mak 65 ing possible a substantial saving in material. To strengthen a structural element against torsional loads, e g drill pipes, suspension springs, torsion bars and tubes, shafts, where the tension compression stresses are directed at 70 degrees from the axis of the element, the grooves or depressions are preferably formed in a pattern having a relatively large pitch as in Figures 3 and 4 By using a pitch, or times the diameter of the element to be treated, on 75 the outside, inside or both surfaces, a 45 degree direction of forming the depression will create locked-in compression stresses directly opposed to the direction of the working torsion stresses. In order to achieve the object of the inven 80 tion the grooves or depressions made in the metal surtace of the element under treatment should be at least 0 001 " ( 0 025 mm) in depth, and not more than 1/1,' ( 1 59 mm) In extremely hard metal the depressions, formed 85 by the pressure applied at spaced intervals, are very shallow The preferred range of depth is l/200 ( O 12 mm) to 1/4 ( 0 4 mm) It wil be apparent that the spacing of grooves or depressions and the depth used will be depen 90 dent on the form of the groove employed The preferred distance between the grooves is l/J ( 32 mm) to '/" ( 0 4 mm) and for general application '/24 " 1 08 mm) is preterred 95 The illustrative examples of the benefits obtained by the invention are given below, using standard American " Almen " strip or split-ring method for hollow elements, as a direct indication of the magntiude of locked 100 in compression stresses and as proof of the improvement of physical properties of structure and machine elements treated (by our method and apparatus. ( 1) Plates 0938 " thick, 3 inches long and 105 /, inch wide, made of high grade steel, were treated by application to one flat surface there of 700 pounds pressure to form transversal grooves as indicated in the following tabulation which shows the permanent deflection created 110 in each plate The amount of this deflection is a direct indication of the magnitude of lockedin compression stresses and of

the improvement of the physical properties of the metal as previously described This is a well known 115 standard test, the so-called " Almen " strip. thus created in the metal are responsible for the great increase in the physical properties of the structural element treated by the invention. The magnitude of the locked-in compressionstresses is controlled by the extend to which the plastically deformed metal is formed in areas A and by the relative width of the intervening elastic metal in areas B with lesser amount of plastic deformation When pressure is applied equally to the whole surface of the the metal element as in the ordinary cold rolling treatment, the mutually interlocking stresses produced by the present invention are not developed. Figure 2 shows diagrammatically a round metal bar 4 which has been treated to form on the surface of the bar helical grooves or depressions 5 and 6 or any other multiple arrangement of helices. In Figure 3 the metal surface 7 has a plurality of spaced parallel grooves or depressions 8 diagonally impressed thereon In Figure 4 the metal surface 7 has two series of spaced parallel grooves or depressions 9 and 10, impressed thereon In this figure the two series of grooves are almost diagonally opposite in direction In Figure 5 the metal surface 7 has a plurality of spaced parallel grooves or depressions 11 In Figures 6 and 7 the metal surface ^ 9 7 has a plurality of spaced grooves or depressions 12 In Figure 8 the metal surface 7 has impressed thereon a plurality of concentric grooves or depressions 13 The grooves or depressions may be applied to the metal member in a great variety of patterns. Representative illustrations of the shapes or contours of the hollows, grooves or depressions are shown in Figures 9, 10, and 11 In Figure 9 the metal element 14 has a U-shaped groove therein In Figure 10 the groove 16 is V-shaped and in Figure 11 the groove 17 is rhombohedral, similar to the internal rifling of hollow elements. The physical properties produced by impressing grooves or depressions or both in metal elements are also governed by the angle between the axis of the groove or depression and the axis of the element under treatment, or, in the case of single or multiple helicalrolling, the pitch of the pattern To strengthen a bar, pipe or other element against reverse bending stresses, considerable locked-in compression stresses parallel to the longitudinal axis of the rod or element should be built up. In such cases the presence of locked-in compression stresses in the transverse direction is not essential but longitudinal stresses as obtained with the pattern shown in Figure 2 795,533 785,533 Untreated portion Space between Width of Deflecgrooves groove Width Surface tion

Inches m M mm mm 'j' 1/It OU Untreated 100 0 l/8 3 17 0 6 2 57 81 6 0 l/AG 1 59 0 6 0 99 62 6 0 l/21 1 06 0 6 0 46 43 10 5 /32 0 80 0 6 0 20 24 13 5 ( 2) Tests of the effect of shot-peening and pattern-rolling on SAE 1060 steel gave the follo-ving comparative results:At a stress of 60000 p s i the untreated metal failed on 56000 cycles, the shot-peening sample failed on 65000 cycles, and the patternrolled sample on 465,000 cycles. Bars of one inch quarter octogan Cr-Ni Mo drill steel were treated by helical rolling at a pressure of 700 pounds to form grooves 20 /,' ( O 4 mm) deep and spaced apart 1/37 k ( 1.06 mm) The bars were then loaded and subjected to reversed bending stresses with the results indicated below:Cycles to failure Endurance Load, in -lb Stress, p s i Untreated Treated Increased 7000 57500 350,000 Unbroken 17 times at 6 x 106 8000 65800 282,000 Unbroken 21 5 times at 6 x 10 ' 9000 74000 80,000 Unbroken 75 times at 6 x 10 e, ( 4) A similar test on 7 " quarter octagon SAE 1080 (carbon steel) drill rod gave the following results:Cycles to failure Endurance Load, in -lb Stress, p s i Untreated Treated Increased 5000 61500 90,000 1,055,000 11 5 times ( 5) Plates O ' 5 " thick of aluminum alloy and magnesium alloy were treated as in Example 1 the pressure applied being 45 pounds, with the following results:ALUMINUM ALLOY Space Width Deflecbetween grooves of groove Untreated portion tion Inches mm mm Widthmm o ll Untreated 100 0 3/32 2 38 O 5 1 88 79 2 5 O 3/G-X 1 19 0 5 0 69 58 8 0 l/32 0 80 O 5 0 30 36 7 11 0 MAGNESIUM ALLOY Untreated 100 0 3/32 2 38 0 6 1 78 74 8 5 O 3/G 1 1 19 0 6 0 58 49 6 12 0 /32 080 0 6 0 2 24 1 18 0 795,533 5 Similar indications on the magnitude of locked-in residual stresses, on the surfaces of eieiilents treated according to this invention, have been obtained using the split-ring method en hollow elements. One example of an apparatus is shown in Figure 12 Tlhis apparatus could be adapted as an attachment to an ordinary lathe or other workshop machine; it comprises a base 18, an upright fixed support 19, and an upright movable support 20 which is sidably adjustable on the base 18 by screw means 21 Thte supports 19 and 20 each carry a removable sleeve 22 which is retained in position by set screws 23. Guided and slidably mounted in each sleeve 22 is a roller support 24 one end 25 of which is tubular in shape to engage a spring 26 and the opposite end of which carries a roller 27 on an axle 28 The compression on the spring 26 may be adjustably varied as desired by a threaded plug 29 The structural member 30 under treatment is, in this case, a quarteroctagon bar Each roller has a peripheral contour complementary to the shape of groove or depression and of pattern which it is proposed to impress in the surface of the element being treated, as for instance is shown in Figures 2 to 11 The periphery of the roller may be smooth as is shown in Figure 12 or notched as shown

at 31 on roller 32 in Figure 12 a. It will be apparent since the rollers 27 are resiliently urged towards each other they may be employed to impress grooves or depressions in the surface of elements of varying crosssectional shapes. In Figure 12 b a roller 32 has a plurality of grooves 31 parallel to the axis of rotation of the roller. In Figure 12 d is shown a roller 32, having -40 where are at an angle of about 450 to the axis of rotation of the roller is shown. In Figure 12 d is shown a roller 32, having two spaced grooved sections carrying grooves 31 which are parallel to the axis of rotation of the roller. Figure 12 e shows a roller 32 similar to that shown in Figure 12 d except that the grooves 31 are at an angle of approximately 45 to the axis of rotation of the roller. In Figure 12 f there is illustrated a roller 32 having a surface parallel rto the axis of rotation of the roller This type of roller is especially adapted for rolling a rod or the like having a tapered end portion; for example, the conical attachment section of a drill rod. It will be understood that the conical, parallel and otherwise shaped surfaces may be provided on two or more separate rollers instead of the single roller shown It may be stated that the loading edge of any of the rollers may be tapered or shaped to facilitate engagement with the article to be treated. In Figure 12 g a roller 32 having grooves 31 inclined at a very steep angle to the axis of rotat on af the roller is shown. Figure 12 h illustrates a roller 32 having grooves 31 substantially parallel to the axis of rotation of the roller Type of rollers shown in Figures 12 g and 12 h are especially adapted for treating the crests and troughs of threads 70 of drill rod attachments in accordance with the method of the invention and as shown in Figure 22 a and Figure 12 i. Any of the above described rollers either in matched or unmatched pairs or groups of 75 two or more may be provided in any of the various forms of apparatus to carry out the method of the present invention It will be apparent that the angular relation of the grooves with respect to the axis of rotation of 80 the roller may vary from 00 to 9-0 depending on the nature of the desired treatment It should also be noted that the types of rollers illustrated are examples only, and any variation as to number and direction of depressions 85 or grooves, or combination of rollers may be used If required all or some of the rollers may be mutually synchronized or interlocked in order to obtain a regularly reproduced pattern 90 In some instances it may be preferable to use only one of the pair of rollers for impressing the necessary depressions or grooves, the other roller having a smooth

periphery and employed to balance the pressure of the first 95 roller and guide the treated element or a Dparatus used The smooth roller is used for smoothing or over-rolling the pattern impressed by the first roller If more than two rollers are employed in any one operation, 100 at least one of the rollers may be used for impressing the necessary depressions and at least one of the remaining rollers employed for smoothing or over-rolling Treatment of structural elements by a method which 105 includes over-rolling is effective in building up and regulating locked-in residual stresses. It may be stated here that the leading edge of any of the rollers may be tapered or shaped to facilitate engagement with the article to be 110 treated. Another form of apparatus is illustrated in Figures 13, 13 a, 13 b, 13 c and 13 d The apparatus in Figure 13 is similar in all respects to that shown in Figure 12 except that the 115 pressure on roller supports 33 is obtained by hydraulic pistons 34 and cylinders 35 which are supplied with fluid through tubes 36. The apparatus for treating the interior surfaces of hollow members, e g, cylinders, 120 hollow-shafts, marine-shafts, tubes, gun barrels, drill pipes and the like and connectors of all these elements, are illustrated in Figures 13 a, 13 b, 13 c and 13 d. The apparatus shown in Figure 13 a com 125 prises a frame 18 having a bore in which is mounted a lazy-tong arrangement supporting a pair of rotatable rollers 27 on axle 28 A spring 26 mounted in the frame 18, and which is adjustable by means of a threaded plug 29, 130 provides the necessary force to the rollers. The apparatus shown in Figure 13 b comprises a frame 35 having a transverse cylindrical bore in which is mounted a pair of pistons 34 Each piston carries an axle 28 on which is rotatably mounted a roller 27. Hydraulic pressure is applied through opening 36 to the pistons 34 and thus supplies the necessary force on the pistons and rollers 27. If desired this apparatus may be altered to one having a fixed diameter by simply removing the hydraulic line and placing the required number of shims, plates or flat springs between the inner ends of the pistons It will be obvious that any suitable arrangement to maintain the rollers in proper relation to the surface to be treated and to prevent the pistons from expanding beyond a safe limit, if required could be provided. A portion of a fixed diameter apparatus is shown in Figures 13 c and 13 d, and comprises a supporting head 24 carrying a pair of rotatably mounted rollers 27 on axle 28, in fixed spaced relation to each other. All apparatus described in this invention may be pushed, pulled and/or rotated along the structural member under treatment.

In Figure 14 a variation of the apparatus shown in Figures 12 and 13 is illustrated The roller 37 is spring loaded as in Figure 12 and the roller 38 is mounted on a support 39 through an axle 40 The required pressure is applied to the support 39 through the lever arm 41 by a spring arrangement 42 The lever arrangement allows the use of a lighter spring in order to obtain the desired pressure on the rollers The apparatus is adapted to be mounted on the ordinary lathe having a driving head 43 and a supporting spindle 44 or in other workshop machines The bar 45 is rotated and moved relatively forward by the head 43 between the rollers 37 and 38 to form a pattern 46 Hydraulic cylinders as shown in Figure 13 may be used to replace the springs. In Figures 15, 16 and 17 another form of suitable apparatus is shown The apparatus comprises a base 47 adapted for attachment to the bed of an ordinary lathe or other workshop machine, a fixed frame member 48 mounted on the base 47 and a movable frame member 49 slidably carried by the fixed frame member and adjustable relative thereto by set screws 50 The movable frame has a lower supporting arm 51 and an upper portion 52 having a bore 53 extending throughout A tubular sleeve or roller supporting member 54 carrying an axle 55 and a roller 56 is slidably mounted in the lower end of the bore 53, guided by a key fixed by means of set screws 57 A threaded cup 58 in the upper end of the bore 53 controls the pressure on a spring 59 in bore 53 Spring 59 is interposed between sleeve 54 and cup 58 A roller 60 on an axle 61 is carried by the supporting arm 51 When a treated object 62 is inserted between the rollers 56 and 60 the rollers are forced apart the pressure on the roller 56 being transferred by the sleeve 54 to the lower end of the spring 59 and the pressure on the roller 70 through the movable member 49 and the cup 58 to the upper end of the spring 59. In use, the above apparatus is mounted on an ordinary lathe and the object to be treated is clamped in the lathe chuck or driving head 75 of the lathe or any other machine used for that purpose The desired pressure is applied to the bar by the rollers 56 and 60 through the spring 59 or by hydraulic means 34, 35 and 36 as shown in Figures 13 and 13 b As 80 the lathe is operated the treated element is rotated and the desired pattern is formed on the element. The different types of apparatus described above could be used for longitudinal, trans 85 verse or helical pattern rolling after adjusting correspondingly the direction of rollers, its feed and relative movement of treated elements If desired, one or more of the rollers could be used, by the angular arrange 90 ment of the pattern of the roller or the position of the roller as a feeding device of the apparatus during the treatment. It will be understood that each pair of iollers in each form of

apparatus illustrated 95 may be arranged with their peripheries in alignment or in offset non-overlapping substantially parallel relation depending upon the pitch and multiplicity of the grooves or depressions and their pressure patterns to be 100 applied to the element under treatment. Furthermore, a plurality of rollers and their combinations of different shapes, dimensions with different patterns and with smooth surfaces if required may be used in each or any 105 form of apparatus above described; one or more of these rollers could have a smooth periphery and be used to balance the pressure of the other pattern-roller or used for the smoothing and over-rolling operation of the 110 pattern impressed by the other roller. With particular reference to the results obtained from the measurements of the m Iagnitude of locked-in residual stresses as produced by the method of this invention, it will 115 be observed that the invention is of far-reaching importance in the treatment of drill rods, drill rod bit attachments, oil drill pipes, drill bits, shafts, pipes, gun barrels and the like, and connectors of all these parts The portion 120 of the element which engages the drill bit or other eleennt is normally most vulnerable to breakage and the application of the present treatment with the apparatus invented to thatportion increases the useful life of the element 125 by at least 70 ' In some tests the life of the rod was increased as much as 700: and in many cases the drill rod failed in the untreated section. A particularly useful form of drill red, drill 130 785,533 195,533 rod bit attachment, and similarly, drill pipe, t shaft and the like, is shown in Figures 18 to 22 a, inclusive The bit end or connector end f 63 of the red 64 using the apparatus described, s is treated over a length required to form e grooves or depressions 65 of various patterns 1 The treated end of the rod may be surrounded s by a wrapping or a continuous unsplitted thimble 66 pressed from one piece of homogeneous or plated metal When the rod, or the like, so wrapped or capped, is forced into I the socket of the bit 67 or other connector, the metal from the thimble enters the grooves and protects the latter from fretting and corroding, I thus maintaining the desired physical pro l perties of the treated rod Similarly, for threaded, push-on, and other types of bit attachments or connector ends, the metal thimbles or shaped ring 66 has a shape conforming with the whole or part of the engaging portions of these elements, to provide a mechanical and electrochemical protection. Referring to Figure 20, for some purposes it is best to treat the rod, and similarly drill pipe, shaft, tubes and the like, with helical grooving or other various patterns at other desired zones Such zones may be, as indicated at 68, at the driving end of the rod which is

subjected to additional stresses and, as indicated at 69, at the area adjacent to the heat treated bit or connecting end 63 of the drill rod or other element This latter area 69 of heat transition zone is commonly termed the metallurgical notch. An additional object of this invention and application of our apparatus is to roll, either on the outside or on the inside, the whole surface of drill pipes; drill rods; conical, threaded or push-on drill rod bit attachments, and connectors of these elements, at a least one zone along its length, using apparatus and rollers developed for this purpose in this invention In order to obtain, at least vartially, the beneficial effect of typical helicalrolling or pattern-rolling according to the main idea of my patent application, the surface of these elements should be rolled in the transverse, circumferential direction, i e in substantially perpendicular direction to the main working stresses. The same apparatus is recommended for treating the interior surface of hollow members, cylinders, hollow shafts (marine shafts), pressure tubes, gun barrels drill pipes and the like and connectors of all these elements by rolling at least one zone, using different combinations of rollers, the whole surface of these elements in order to obtain the beneficial effect similar to the so-called " auto-frettage " This new method of mechanical auto-frettage by internal rolling or internal over-rolling of hollow members is based on plastic deformation by rolling or squeezing of the interior of these structural elements to a depth as required by dimensions and future applicaions and loading conditions of these elements. Auto-frettage is a known process for manuacturing pressure vessels, in which the innerurface layers of a plain tube are stressed by expansion beyond the yield strength by 70 hydraulic pressure, so that residual compresive stresses are created.

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* GB785534 (A)

Description: GB785534 (A) ? 1957-10-30

Metal members having improved physical properties

Description of GB785534 (A)

PATENT SPECIFICATION 785,534 Date of Application and filing Complete Specification Jan 18, 1954. No 34358/55. Application made in Canada on June I I, 1953. (Divided out of No 785,533). Complete Specification Published Oct 30, 1957. Index at Acceptance: -Classes 20 ( 2), F 1 83; 83 ( 4), V 2; 85, AIC; 99 ( 1), G 24 A 2, R; and 124, C 6 (A: H). International Classification: -1323 k B 25 d E 04 c E 21 b F 06 b, l. COMPLETE SPECIFICATION Metal Members having improved Physical Properties I, TADEUSZ WLADYSLAW WLODEK, of 297, Fifth Avenue, Ottawa, Ontario, Canada, of Canadian Nationality, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described by the following statement:- This invention relates to metal members, their welds, joints, fillets, threads, metallurgical notches, and the like; having improved physical properties brought about by the method and apparatus as disclosed in our copending application No 1373 of 1954 (Serial No 785,533). It is well known that the physical or mechanical properties of metal constituting preformed elements may be strengthened and improved by various treatments such as shotpeening, regular cold rolling, carburizing or nitriding of steel, induction hardening, heat treatment, and others The fields in which the various methods have been employed depend on the nature of the metal to be treated, the shape of the element, and the economy of the treatment A common method of improving the surface properties of steel axles or the like is to roll the entire surface of the axle under fairly high pressure. Such operation affords a small increase in the physical properties of the metal constituting the axle, and, because of longer time required, is a relatively costly operation. It has now been discovered that surprisingly improved properties are produced in metals constituting structural elements, rails, plates, bars, rods, tubes, drill pipes, drill pip-.

connectors-tool joints, thin airplane' sheeting and channels and the like, of simple and complicated form their welds joints, fillets, threads, etc, by creating within the material locked-in residual stresses which work against the stresses imposed upon the structural element as it is used, thus increasing the useful life of the element, or the load which it is capable of carrying These locked-in reilPrice 3 S 6 d l dual stresses are created by different types oi apparatus developed for the purpose of applying pressure to portions of the material to give it permanent or so-called plastic deformation and leaving adjacent portions of the material in its normal or elastic form It appears that the alternate juxtaposition of these regions of plastically deformed material with those in the normal elastic form or practically normal elastic form results in an interlocking of the internal stresses in the treated areas of the material to enable the structural element to withstand heavier loads or have a longer useful life. This new treatment is based on the creation of locked-in residual stresses through the introduction of mainly plastically deformed regions in alternate juxtaposition with regions substantially plastically deformed In general, juxtaposition of regions plastically deformed with regions of lesse plastic deformation, both regions being arranged in a regular or irregular pattern, is the topic of this treatment The transition between these two regions may be gradual or abrupt, and the built-in residual stresses are substantially perpendicular to the direction of plastically deformed regions i.e, direction of pattern It should be also emphasized that impression of grooves and depressions provides, through so called mutual interlocking phenomena, a controllable mn.echanism of plastic deformation of treated surfaces, resulting in greatly improved physical qualities of material treated by this invention. It is an object of this invention to provide a method for greatly increasing the physical properties of metallic elements by rolling or otherwise impressing grooves or depressions of various patterns and shapes on the surface of such elements and an effective apparatus for carrying out this method. It is a particular object of this invention to provide an apparatus for improving the physil cal properties, particularly resistance to fatigue, e U IMI,1 1'i 1, ' 7 785,534 of a drill rod, drill rod bit attachment, drill pipe, drill bits, shafts and similar elements, and connectors of all these elements by rolling on or impressing on the outside or on the inside or on both surfaces a plurality of shallow grooves or depressions, or both, on the engaging end of these elements, threaded connections, and, if desired, on other parts thereof The invention will be described with reference to the

accompanying drawings in which Figure 1 is an illustration of a structural element showing sections of plastically deformed metal, each in juxtaposed relation to a section of metal substantially in its normal elastic form, as produced by the invention. Figure 2 is a diagrammatic illustration of one pattern of treatment of a metal bar as produced by my apparatus. Figures 3 4, 5, 6 and 8 are diagrammatic views showing various examples of patterns of treatment as produced by the apparatus. Figure 7 is a section view along the line 7-7 of the pattern shown in Figure 6, as produced by the apparatus. Figures 9, 10 and 11 are enlarged views in section of a piece of metal showing various examples of shapes of grooves and depressions, as produced by the apparatus. Figures 12, 13, and 13 a, b, c, d, are elevation views partly in section of various forms of apparatus for carrying out the method of the invention. Figure 12 a, b, c, d, e, f, g, It, and i, are elevation of different examples of rollers used in our apparatus. Figure 14 is a diagrammatic elevation view, partly in section, illustrating another form of apparatus for carrying out the invention. Figure 15 is a side elevation view, partly in section of another form of apparatus. Figure 16 is a front elevation view of the apparatus shown in Figure 15. Figure 17 is a section view taken on the line 17-17 of Figure 15. Figure 18 is a section of a drill rod bit attachment with attached bit treated in accordance with the invention and in our apparatus. Figure 19 is a section view along the line SC 19-19 of Figure 18. Figure 20 is a blown up side elevation view of a drill rod, with conical drill rod attachment, thimble and bit, treated in our apparatus. Figure 21 is a cross section view of the drill rod taken on the line 21-21 of Figure 20, and Figure 22 is an enlarged sectional view of a portion of a drill rod bit attachment assenmb v. Figure 22 a is a view of a threaded drill rod attachment, treated in our apparatus. In accordance with the invention the physical properties, specially fatigue, corrosion fatigue, stress corrosion, static and dynamic strength; resistance against fretting, wear and erosion of structural metal members arc greatly improved by impressing shallow hollows, grooves or depressions at spaced intervals thereon, said intervals being so spaced as to leave between adjacent pairs of grooves or 70 depressions or the like a portion of metal which has not been directly subjected to deformation.

The effect produced by the method of the invention is characterized by the magnitude 75 and direction of the locked-in residual stresses which are produced in the metal of the structural element under treatment by the different combinations of: force used, direction of the applied force, patterns and their sequence, 80 and the depth, shape and cross-section of the depressions and grooves In order to increase the effect of our treatment the structural element, if required, could be treated while under stress The residual stresses thus 85 created are directed against the working stresses imposed on the structural element, with the result that the element has longer useful life and greater capacity to resist the strain caused by the load imposed on the ele 90 ment. The hollows, grooves or depressions may be of any desired shape and may be applied by any desired means to various types of metal structural members, their welds and joints, 95 fillets, threads, metallurgical notches, and the like, in a variety of patterns The grooves er depressions may be impressed by rolling, helical rolling, pressing, stamping, hammering, squeezing, drawing and twisting or the like, 100 depending upon the character of the form of the rilober to be treated In the case of tubular metal members, pressure vessels, cylinders and other hollow members, the grooves or depressions may be impressed on 105 the outer or inner surface or both; these impressed grooves and crests, the surface of which may be either machined or not, may serve also as guides for other moving elements or serve as a "grip" for paint, plastic and 110 other surface protective material It will be appreciated that the crests and troughs of the depressions or grooves may be subjected to any subsequent treatment such as machining, grinding, or the like Furthermore, the 115 grooves may be so designed as to provide guides for elements arranged to move along the surface thereof For example, the rifling of a gun barrel may be produced by the mathod of the present invention The grooves 120 so formed partly, i e after pre-machining, or completely by this method not only greatly improve the physical properties of the gun barrel, through the " auto-frettage-rolling " described in my applications, but at the same 125 time provide the necessary rifling It will be obvious that there are many other practical adaptations of the present invention. In the enlarged view of Figure 1 there is illustrated pictorially the effect of forming on 130 785,534 the surface of a metal member 1 valleys or grooves 2 leaving crests or untreated portions 3 As a result of the pressure applied to make the grooves or depressions 2 there is produced in the areas A metal of substantially all plastic or permanent deformation whereas the metal of areas B remains substantially in its original elastic form The mutual interlocking

stresses thus created in the metal arc responsible for the great increase in the physical properties of the structural element treated by the invention The magnitude of the locked-in compression stresses is controlled by the extent to which the plastically deformed metal is formed in areas A and by the relative width of the intervening elastic metal in areas B with lesser amount of plastic deformation. When pressure is applied equally to the whole surface of the metal element as in the ordinary cold rolling treatment, the mutually interlocking stresses produced by the present invention are not developed. Figure 2 shows diagrammatically a round metal bar 4 which has been treated to form on the surface of the bar, helical grooves or depressions 5 and 6 or any other multiple arrangement of helices. In Figure 3 the metal surface 7 has a plurality of spaced parallel grooves or depressions 8 diagonally impressed thereon In Figure 4 the metal surface 7 has two series of spaced parallel grooves or depressions 9 and 10, impressed thereon In this figure the two series of grooves are almost diagonally opposite in direction In Figure 5 the metal surface 7 has a plurality of spaced parallel grooves or depressions 11 In Figures 6 and 7 the metal surface 7 has a plurality of spaced grooves or depressions 12 In Figure 8 the metal surface 7 has impressed thereon a plurality of concentric grooves or depressions 13. The grooves or depressions may be applied to the metal member in a great variety of patterns. Representative illustrations of the shapes or contours of the hollows, grooves or depressions are shown in Figures 9, 10 and 11 In figure 9 the metal element 14 has a U-shaped groove therein In Figure 10 the groove 16 is V-shaped and in Figure 11 the groove 17 is rhombohedral, similar to the internal rifling of hollow elements. The physical properties produced by impressing grooves or depressions or both in metal elements are also governed by the angle between the axis of the groove or depression and the axis of the element under treatment, or, in the case of single or multiple helicalrolling, the pitch of the pattern To strengthen a bar, pipe or other element against reverse bending stresses, considerable lockedin compression stresses parallel to the longitudinal axis of the rod or element should be built up In such cases the presence of locked-in compression stresses in the trans 65 verse direction is not essential, but longitudinal stresses as obtained with the pattern shown in Figure 2 or Figure 5, applied on the outside, inside or both surfaces where the pitch is small, are recommended Performed 70 measurements of the ratio of longitudinal and transverse lock-in compression stresses, gave for this pattern a factor larger than one This results in the reduction of

working stresses in bending, making possible a substantial saving 75 in material. To strengthen a structural element against torsional loads, e g drill pipes, suspension springs, torsion bars and tubes, shafts, where the tension compression stresses are directed 80 at 45 degrees from the axis of the element, the grooves or depressions are preferably formed in a pattern having a relatively large pitch as in Figures 3 and 4 By using a pitch, jr times the diameter of the element to be treated, on 85 the outside, inside or both surfaces, a 45 degree direction of formnig the depression will create lock-in compression stresses directly opposed to the direction of the working torsion stresses 90 In order to achieve the object of the invention the grooves or depressions made in the metal surface of the element under treatment should be at least 0 001 " ( 0:'025 mm) in depth and not more than '/,(" ( 1 59 mm) 95 In extremely hard metal the depressions, formed by the pressure applied at spaced intervals, are very shallow The preferred range of depth is l/200 ( 0 12 mm) to '/6, ( 0 4 mm.) It will be apparent that the spacing 100 of grooves or depressions and the devpth used will be dependent on the form of the groove employed The preferred distance between the grooves is l/8 ( 3 2 mm) to '/J 4 " ( 0 4 mm.) and for general application l/24 " ( 1 08 105 mm.) is preferred. The illustrative examples of the benefits obtained by the invention are given below, using standard American "Almen" strip or split-ring method for hollow elements, as a 110 direct indication of the magnitude of lockedin compression stresses and as proof of the improvement of physical properties of structure and machine elements treated by our method and apparatus 115 ( 1) Plates 0938 " thick, 3 inches long and l/2 inch wide, made of high grade steel, were treated by application to one flat surface thereof of 700 pounds pressure to form transversal grooves as indicated in the following 120 tabulation which shows the permanent deflection created in each plate The amount of this deflection is a direct indication of the magnitude of locked-in compression stresses and of the improvement of the physical proper, 125 ties of the metal as previously described This is a well known standard test the so-called " Almen " strip. 785,534 Space between grooves Width of groove Untreated portion Deflection Width Surface inches mm mm mm /1000 Untreated 100 0 l/8 3 17 0 6 2 57 81 6 0 1.59 0 6 0 99 62 6 0 1.06 0 6 0 46 43 10 5 l/32 080 0 6 0 20 24 13 5 ( 2) Tests of the effect of shot-peening and pattern-rolling on SAE 1060 steel gave the following comparative results:At a stress of 60,000 p s i the untreated metal failed on 56,000 cycles, the shotpeening sample failed on 65,000 cycles, and the pattern-rolled sample on 465,000 cycles r Bars of one inch quarter

octagon Cr-Ni-Mo drill steel were treated by helical rolling at a pressure of 700 pounds to form grooves I/,j 20 ( 0.4 mm) deep and spaced apart '/24 " ( 1 06 mm.) The bars were then loaded and subjected to reversed bending stresses with the results indicated below:o Cycles to tailure Endurance Load, in -lb Stress, p s i Untreated Treated increased 7000 57500 350,000 Unbroken 17 times at 6 X 106 8000 65800 282,000 Unbroken 21 5 times at 6 x 106 9000 74000 80,000 Unbroken 75 times at 6 X 106 ( 4) A similar test on following results: A/&t quarter octagon SAE 1080 (carbon steel) drilled rod gave the Cycles to failure Endurance Load, in -lb Stress, p s i Untreated Treated increased 5000 61,500 90,OG O 1,055,000 11 5 times ( 5) Plates 005 " thick of aluminium alloy Example 1, th, pressure applied being 45 and magnesium alloy were treated as in pounds with the following results:Space between grooves inches mm. ALUMINUM ALLOY Width of Untreatec groove portion mm. Width mm. Deflection Surface 1/11001 Untreated 100 O 3/3 A -,2 38 0 5 1 88 79 2 5 0 V/4 1 19 0 5 0 69 58 8 0 /,2 0 80 0 5 O 30 36 7 11 0 MAGNESIUM ALLOY Untreated 100 0 3/32 2 38 0 6 1 78 74 8 5 0 /64 1 19 0 6 0 59 49 6 12 0 l/32 0 80 0 6 0 2 24 1 18 0 785,534 Similar indications on the magnitude of locked-in residual stresses, on the surfaces of elements treated according to this invention, have been obtained using the split-ring method on hollow elements. One example of an apparatus is shown in Figure 12 This apparatus could be adapted as an attachment to an ordinary lathe or other workship machine; it comprises a base 18, an upright fixed support 19, and an upright movablel support 20 which is slidably adjustable on the base 18 by screw means 21 The supports 19 and 20 each carry a removable sleeve 22 which is retained in position by set screws 23 Guided and slidably mounted in each sleeve 22 is a roller support 24 one end 25 of which is tubular in shape to engage a spring 26 and the opposite end of which carries a roller 27 on an axle 28 The compression on the spring 26 may be adjustably varied as desired by a threaded plug 29 The structural member 30 under treatment is, in this case, a quarter-octagon bar Each roller has a peripheral contour complementary to the shape of groove or depression and of pattern which it is proposed to impress in the surface of the element being treated, as for instance is shown in Figures 2 to 11 The periphery of the roller may be smooth as is shown in Figure 12 or notched as shown at 31 on roller 32 in Figure 12 a L It will be apparent since the rollers 27 are resiliently urged towards each other they may be employed to impress grooves or depressions in the surface of elements of varying cross-sectional shapes. In Figure 12 b a roller 32 has a plurality of grooves 31 parallel to

the axis of rotation of the roller. In Figure 12 c a roller 32 having grooves 31 which are at an angle of about 450 to the axis of rotation of the roller is shown. In Figure 12 d is shown a roller 32, having two spaced grooved sections carrying grooves 31 which are parallel to the axis of rotation of the roller. Figure 12 e shows a roller 3 i similar to that shown in Fig 12 d except that the grooves 31 are at an angle of approximately 450 to the axis of rotation of the rollert In Figure 12 f there is illustrated a roller 32 having a surface parallel to the axis of rotation of the roller This type of roller is especially adapted for rolling a rod or the like having a tapered end portion; for example, the conical attachment section of a drill rod It will be understood that the conical, parallel and otherwise shaped surfaces may be provided on two or more separate rollers instead of the single roller shown It may be stated that the loading edge of any of the rollers may be tapered or shaped to facilitate engagment with the article to be treated. In Figure 12 g a roller 32 having grooves 31 inclined at a very steep angle to the axis of rotation of the roller is shown. Figure 12 h illustrates a roller 32 having grooves 31 substantially parallel to the axis of rotation of the roller Type of rollers shown in Figures 12 and 12 h are especially 70 adapted for treating the crests and troughs of threads of drill rod attachments in accordance with the method of the invention and as shown in Figure 22 a and Figure 12 i. Any of the above described rollers either in 75 matched or unmatched pairs or groups of two or more may be provided in any of the various forms ot apparatus to carry out the method of the present invention It will be apparent that the angular relation of the grooves 80 with respect to the axis of rotation of the roller may vary from 00 to 900 depending on the nature ot the desired treatment It should also be noted that the types of rollers illustrated are examples only, and any varia 85 tion as to number and direction of depressions or grooves, or combination of rollers may be used If required all or some of the rollers may be mutually synchronized or interlocked in order to obtain a regularly reproduced 90 pattern. In some instances it may be preferable to use only one of the pair of rollers for impressing the necessary depressions or grooves, the other roller having a smooth periphery and 95 employed to balance the pressure of the first roller and guide the treated element or apparatus used The smooth roller is used for smoothing or over-rolling the pattern impressed by the first roller If more than two 100 rollers are employed in any one operation, at least one of the rollers may be used for impressing the necessary depressions and at least one of the

remaining rollers employed for emoothing or over-rolling Treatment of 105 structural elements by a method which includes over-rolling is effective in building up and regulating locked-in residual stresses. It may be stated here that the leading edge of any of the rollers may be tapered or shaped 110 to facilitate engagement with the article to be treated. Another form of apparatus is illustrated in Figures 13, 13 a, 13 b, 13 c and 13 d The apparatus in Figure 13 is similar in all res 115 pects to that shown in Figure 12 except that the pressure on roller supports 33 is obtained by hydraulic pistons 34 and cylinders 35 which are supplied with fluid through tubes 36 120 The apparatus for treating the interior surfaces of hollow members, e g, cylinders, hollow-shafts, marine-shafts, tubes, gun barrels, drill pipes and the like and connectors of all these elements, are illustrated in Figures 125 13 a, 13 b, 13 c and 13 d. The apparatus shown in Figure 13 a comprises a frame 18 having a bore in which is amounted a lazy-tong arrangement supporting a pair of rotatable rollers 27 on axle 28 A 130 spring 26 mounted in the frame 18, and which is adjustable by means of a threaded plug 29, provides the necessary force to the rollers. The apparatus shown in Figure 13 b comprises a frame 35 having a transverse cylindrical bore in which is mounted a pair of pistons 34 Each piston carries an axle 28 on which is rotatably mounted a roller 27. Hydraulic pressure is applied through opening 36 to the pistons 34 and thus supplies the necessary force on the pistons and rollers 27. If desired this apparatus may be altered to one having a fixed diameter by simply removing the hydraulic line and placing the required number of shims, plates or flat springs between the inner ends of the pistons It will be obvious that any suitable arrangement ta maintain the rollers in proper relation to the surface to be treated and to prevent th-w pistons from expanding beyond a safe limit, if required could be provided. A portion of a fixed diameter apparatus is shown in Figures 13 c and 13 d, and comprises a supporting head 24 carrying a pair of rotatably mounted rollers 27 on axle 28 in fixed spaced relation to each other. All apparatus described in this invention may be pushed, pulled and/or rotated along the structural member under treatment. In Figure 14 a variation of the apparatus shown in Figures 12 and 13 is illustrated The roller 37 is spring loaded as in Figure 12 and the roller 38 is mounted on a support 39 through an axle 40 The required pressure is applied to the support 39 through the lever arm 41 by a spring arrangement 42 The lever arrangement allows the use of a light spring in order to obtain the desired pressure on the Yellers The

apparatus is adapted to be mounted on the ordinary lathe having a driving head 43 and a supporting spindle 44 or in other workshop machines The bar 45 is rotated and moved relatively forward by the head 43 between the rollers 37 and 38 to form -45 a pattern 46 Hydraulic cylinders as shown in Figure 13 may be used to replace the springs. In Figures 15, 16 and 17 another form of suitable apparatus is shown The apparatus comprises a base 47 adapted for attachment to the bad of an ordinary lathe or other workshop machine, a fixed frame member 48 -mounted on the base 47 and a movable frame -member 49 slidably carried by the fixed frame memrber and adjustable relative thereto by set screws 50 The movable frame has a lower supporting arm 51 and an upper portion 52 having a bore 53 extending throughout A tubular sleeve or roller supporting member 54 carrying an axle 55 and a roller 56 is slidably mounted in the lower end of the bore 53, guided by a key fixed by means of set screws 57 A threaded cup 58 in the upper end of the hore 53 controls the pressure on a spring 59 in bore 53 Spring 59 is interposed between sleeve 54 and cup 58 A roller 60 on an axle 61 is carried by the supporting arm 51 When a treated object 62 is inserted between the rollers 56 and 60 the rollers are forced apart, the pressure on the roller 56 being transferred by the sleeve 54 to the lower end of the spring 70 59 and the pressure on the roller 60 through th movable member 49 and the cup 58 te tht upp'Er end of the spring 5 Q In use, the above apparatus is mounted on an ordinary lathe and the object to be treated 75 is clamped in the lathe chuck or driving head of the lathe or any other machine used for that purpose The desired pressure is applied to the bar by the rollers 56 and 60 through the spring 59 or by hydraulic means 34, 35 and 80 36 as shown in Figures 13 and 13 b As the lathe is operated the treated element is rotated and the desired pattern is formed on the el ment. The different types of apparatus described 85 above could be used for longitudinal, transverse or helical pattern rolling after adjusting correspondingly the direction of rollers, its seed and relative movement of treated el rgents If desired, one or more of the rollers 90 could b used, by the angular arrangement of dhe pattern of the roller or the position of the Loller as a feeding device of the apparatus during the treatment. It will be understood that each pair of 95 rollers in each form of apparatus illustrated may be arianged with their peripheries in alignment or in ofset non-overlapping substantially parallel relation depending upon the pitch and inultiplicity of the grooves or 100 depressions and their pressure patterns to he applied to the element under treatment. Furthermore, a plurality of rollers and their combinations of

different shapes, dimensions with diiefelen L patterns and with smooth sur 10 faces if required may be used in each or any form of apparatus above described; one or more of these rollers could have a smooth periphery and be used to balance the pressure of the other pattern-roller or used for the 110 smoothing and over-rolling operation of the pattern impressed by the other roller. With particular reference tr the results obtained from the measurements of the magnitude of locked-in residual stresses as produced 115 by the method of this invention, it will be observed that the invention is of far-reaching importance in the treatment of drill rods, drill rod bit attachments, oii drill pipes, drill bits, shafts, pipes, gun barrels and the like, and 12 C connectors of all these parts The portion of the element which engages the drill bit or other element is normally most vulnerable to breakage and the application of the present treatment with the apparatus invented to that 12; portion increases the useful life of the element by at least 70 ' In some tests the life of therod was increased as much as 700 3 and in many cases the drill rod failed in the untreated section 13 ( 785,534 785,534 A particularly useful form of drill rod, drill 1 rod bit attachment, and simliarly, drill pipe, shaft and the like, is shown in Figures 18 to 22 a, inclusive The bit end or connector end 63 of the rod 64 using the apparatus described, is treated over a length required to form grooves or depressions 65 of various patterns. The treated end of the rod may be surrounded by a wrapping or a continuous unsplitted thimble 66 pressed from one piece of homogeneous or plated metal When the rod, or the like, so wrapped or capped, is forced into the socket of the bit 67 or other connector, the metal from the thimble enters the grooves and protects the latter from fretting and corroding, thus maintaining the desired physical properties of the treated rod Similarly, for threaded, push-on, and other types of bit attachments or connector ends, the metal thimble or shaped ring 66 has a shape conforming with the whole or part of the engaging portions of these elements, to provide a mechanical and electrochemical protection. Referring to Figure 20, for some purposes it is best to treat the rod, and similarly drill pipe, shaft, tubes and the like, with helical grooving or other various patterns at other desired zones Such zones may be, as indicated at 68, at the driving end of the rod which is subjected to additional stresses and, as indicated at 69, at the area adjacent to the heat treated bit or connecting end 63 of the drill rod or other element This latter area 69 of heat transition zone is commonly termed the metallurgical notch. An additional object of this invention and application of our apparatus is to roll, either on the outside or on the inside, the

whole surface of drill pipes; drill rods; conical, threaded or push-on drill rod bit attachments, and connectors of these elements, at least one zone along its length, using apparatus and rollers developed Zor this purpose in this invention. In order to obtain, at least partially, the beneficial effect of typical helical-rolling or patternrolling according to the mains idea of my patent application, the surface of these elements should be rolled in the transverse, circumferential direction, i e in substantially perpendicular direction to the main working stresses. The same apparatus is recommended for treating the interior surface of hollow members, cylinders, hollow shafts (marine shafts), pressure tubes, gun barrels, drill pipes and the like and connectors of all these elements by rolling at least one zone, using different combinations of rollers, the whole surface of these elements in order to obtain the beneficial effect similar to the so-called " auto frettage ". This new method of mechanical auto-frettage by internal rolling or internal over-rolling of hollow members is bases on plastic deformation by rolling or squeezing of the interior of these structural elements to a depth as 65 required by dimensions and future applications and loading conditions of these elements. Auto-frettage is a known process for manufacturing presssure vessels, in which the innersurface layers of a plain tube are stressed by 70 expansion beyond the yield strength by hydraulic pressure, so that residual compressive stresses are created.

* Sitemap * Accessibility * Legal notice * Terms of use * Last updated: 08.04.2015 * Worldwide Database * 5.8.23.4; 93p

* GB785535 (A)

Description: GB785535 (A) ? 1957-10-30

Improvements in the production of footwear

Description of GB785535 (A)

PATENT SPECIFICATION Date of filing Complete Specification: Jaly 1, 1954. Application Date: Jan 9, 1954 N\ o 675 /54. Complete i S'pecofication Publighed: Oct 30 1957. Index at Acceptance:-Class 17 ( 2), B 1 (A 4: 08: C 5: K). International Classification:-A 43 d. COMPLETE SPECIFICATION. Improvements in the Production of Footwear. We, NU-STILO FOOTWEAR LIMITED, a British Company, of George Street, Trading Estate, Bridgend, Glamorgan, and SAMUEL BLACK, a British Subject, of the Company's address, 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:- The present invention relates to improvements relating to the production of footwear and to new constructions of footwear so produced. More especially the present invention is concerned with the production of welted footwear by a method which eliminates many of the operations involved in the conventional methods of production of welted footwear and at the same time provides a construction which has improved properties. The features of the present invention are applicable to the production of various types of footwear, including those types which are commonly produced in welted form, as well as other types of footwear, and all of which are characterised by the provision of a welt, thus conferring the advantages of the welted construction. Heretofore the production of welted footwear, that is footwear having a welt strip which underlies and projects outwardly of the marginal portion of the upper and is stitched thereto and to which in turn a sole is directly or indirectly attached, has required numerous working operations and in consequence footwear produced by this method has been expensive and difficult to produce at an acceptable price. The present invention is more specifically directed to a new method of footwear production wherein a true welt is used which, just as in conventional types of welted constructions, is stitched to the upper and in lPrice 3 s 6 d l turn a sole is directly or indirectly sewn or otherwise attached to the welt so that the resulting construction of the footwear is similar to that obtained by the conventional welted construction and the well-recognised advantages of this construction are obtained despite the fact that only comparatively few working

operations are concerned. A further object of the invention is to provide a method of footwear production which does not require the use of an insole of the normal character and more specifically does not require the use of a channelled insole. A still further object of the invention is to provide a method of producing welted footwear of various types by the slip-lasting method, thus combining the well-known advantages of this method with the advantage of being able to produce a true welted construction. Another object of the invention is to provide a method of footwear construction wherein fitting of a welt strip is effected without the article being fixed to a last, further and subsequent stages in the production involving slip-lasting the upper with the, welt strip fixed thereto, the welt strip being thereafter turned to its final position. A method of producing footwear according to the present invention comprises assembling a pre-formed upper and a welt strip, the latter being skived and serrated at one edge and stitching the welt strip to the upper along a line extending parallel and comparatively close to the other edge of the welt strip and thereafter turning the welt inwardly so that the major part of the welt strip including the skived edge lies beneath the upper and as a result of such skiving is capable of receiving normal soling material, and the minor portion thereof forms an outwardly extending welt. In the preferred method the formation of 7855535 785,535 the footwear article is effected by the sliplasting process and the stitching of the welt to the edge of the upper also serves to secure the edge of a sock within the upper, these parts being subsequently forced on to a last before the welt is turned to lie parallel to the bottom of the last. A suitable filler is of course incorporated in the construction which lies beneath the sock and it may either lie at its edges beneath the welt strip as turned inwardly to under-lie the sock or it may terminate short of the edge of the welt strip After such a filler has been applied any suitable type of sole such as a through sole or part sole is fitted to the base of the footwear and is attached at its edges to the outwardly projecting portion of the welt strip, being for example secured either exclusively by adhesive solution or in some cases with the addition of appropriate stitching or other fastening. According to the position of the width of the welt strip at which stitching to the upper and to the sock is effected it is possible to produce footwear with various amounts of welt strip showing according to prevailing fashion and the type of footwear being produced If this projection is reduced to a very low value there may be practically no projection and the so-called "pump-edge" shoe is or can be produced.

The stitching of the welt strip to the upper and to the sock is conveniently effected in such a manner that the position of the line of stitching is defined by the marginal edges of the welt strip, permitting the stitching to be correctly effected and giving a uniform appearance to the finished article Since such stitching is effected away from the last the advantage is obtained that normal types of footwear sewing machines can be used with a guide whereby guidance of the stitching is effected solely from the edges of the welt strip Such a guide may for example consist of a pair of guide elements the spacing of which is equal to the width of the welt strip so that the footwear being produced can be presented to the machine with o the welt strip fed into the guide, the welt strip lying approximately at right angles to the plane occupied by the sole later to be attached to the article, that is with the welt lying in approximately the same direction as the edge of the upper so that stitching through the welt strip and the upper, and preferably also a sock fitted therein, can be readily effected in a simple and straightforward manner. The welt strip may be formed of any suitable firm and flexible material including leather, plastic composition, fabric, laminated materials, the so-called reconstituted materials or combinations of any of these materials. The features of the present invention are shown by way of example on the accompanying drawings in which:Figs 1 to 3 are sections through an article of footwear according to the invention show 70 ing different stages in the production; Fig 4 is a view corresponding to Fig 2 showing a slightly modified form of construction; Fig 5 is a view showing in elevation and 75 section the form of the welt strip used; and Fig 6 is a view, corresponding to Fig 2 showing a different form of footwear which may be produced according to the invention. Referring to Figs 1, 2 and 3 of the drawing SO an upper 8 is formed in a usual way and a sock 9 is provided which has a turned edge which is to be sewn thereto conveniently at the same operation by which a welt strip 10 is sewn to the upper 8 85 The welt strip 10 is formed of any suitable material which has the characteristics of firmness, flexibility and stitch holding qualities For exnample it may be formed of leather, one of the plastic materials used 90 in the footwear trade, fabric or bonded fabric, laminated materials, the so-called reconstituted materials or compositions, i e. bonded leather comminutes which may be mixed with rubber or rubber-like composi 95 tions or combinations of the aforesaid materials It is of uniform width throughout and the lower edge, as seen in Fig 1, is skived or thinned as indicated at 11 and said edge is also deeply serrated as will be 100 more clearly apparent from Fig 5 This welt strip is described and claimed in Specification No 6156/56

(Serial No 785,536). It will be seen that the welt strip 10 is applied against the lower edge of the upper 1 oo and is sewn thereto by a line of stitching 12 which preferably also traverses the depending edge portion of the sock 9 Thus the welt strip runs initially in a direction perpendicular to that which it will occupy in 11 o the finished shoe and parallel to and against the edge of the upper, which permits stitching to be readily effected by a simple attachment to the existing types of footwear sewing machines After the stitching has been in carried out right around the edge of the upper, the footwear is forced onto a last as in the slip-lasted method and the welt strip is turned inwardly to underlie the edge of the sock 9 and the outer edge of the upper 120 8, which obviously involves a turning movement through approximately 900 to the position shown in Fig 2 The deep serrations in the lower edge of the welt permit the latter to conform readily with the curved i 23 edge configuration of the sole. Thus it will be seen that the primary features of the present invention are the manner in which the welt 10 is stitched to the uppzr The position of the stitching 12 130 185,535 is chos en so that only the width 6 f the welt which will be seen at the edge of the finished article lies above the feather line or corner between the upper and the welt, allowing of course for the thickness of the material of the upper, as will be apparent from Figs 1 and 2. The part-formed footwear is then sliplasted; during this operation the last, indicated in position at 13 of Fig 1, brings the article to the intended shape after which adhesive solution is applied to the inside of the sock 9, being carried well into the corners at the edges In the case of Fig 2 la a filler 14 of suitable material is now laid beneath the sock 9, the said filler having been initially treated with adhesive solution, and after application is given a further coat of adhesive solution on its outer surface. When the adhesive solution has dried the welt edge is turned over on to the base of the filler to occupy the position shown in Fig 2 in which the formerly upwardly extending part of the welt strip is now turned outwardly in the position normally occupied by a welt in normal types of welted footwear construction, the base of the upper is turned inwardly over the welt strip and the edge of the sock 9 is turned re-entrantly upon itself Due to the serrations and the skiving the welt strip can be readily made to lie smoothly beneath the filler without surplus material to provide a flat surface to receive the soling material. Sole material may now be applied to the under side of the footwear so formed and one or more soles of the normal type may be applied according to the character and type of footwear involved In the case

of Fig. 3 a middle sole 15 is first applied to the under side of the welt strip and to the portion of the filler 14 not covered by the lower edge of the welt strip and this may be followed by a through sole 16, or alternatively a middle and through sole may be utilised This sole or these soles can be struck, welded or otherwise attached to the edge of the welt strip in the manner known in this art The soles may be formed of any suitable material for example leather, rubber or compositions of leather and rubber, crepe rubber, fine cellular rubber or the like. Fig 4 shows an alternative construction which differs from that shown in Figs 1 and 3 only in that the filler 14 is applied after the welt strip 10 has been turned to underlie the article; the filler 14 then occupies the space defined by the inner edge of the welt strip as will be clearly apparent on Fig 4 Thereafter a middle sole and a through sole or alternatively a combined nmiddle and through sole may be applied and the footwear completed as above described. It will be realised that an important advantage of the present invention is that the completion of the footwear from the stage of closing the upper to the application of the main sole may be effected in relatively 70 few operations and consequently the production of articles of footwear, which are indeed true welted footwear, is simplified and cheapened It will of course be realised that stitching of the welt to the upper and 75 the sock can be effected on ordinary types of footwear sewing machines by the provision of guide means co-operating with the welt strip which may be fed to the machine at the same time as the preformed 80 upper is presented. Fig 6 represents how it is possible according to the invention to produce an article of footwear according to the invention having a slightly different appearance It is 85 assumed in this case that it is desired to produce a pump-edge shoe, that is a shoe having substantially no visible welt To do this it is merely necessary to adjust the guide means so as to run the line of stitching 90 through the welt substantially nearer the edge of the welt strip so that when the latter is turned the outer edge thereof does not substantially project beyond the edge of the upper 95

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* GB785536 (A)

Description: GB785536 (A) ? 1957-10-30

Improved welt for footwear

Description of GB785536 (A)

PATENT SPECIFICATION Date of filing Complete Specification: July 1, 1954. Application Date: Jan 9, 1954 No 6156/56. (Divided out of No 785,535). Complete Specification Published: Oct 30, 1957. Index at Acceptance:-Class 17 ( 2), B 105. International Classification:-A 43 d. COMPLETE SPECIFICATION. Improved Welt for Footwear. We, Nu-STI Lo FOOTWEAR LIMITED, a British Company, of George Street, Trading Estate, Bridgend, Glamorgan, and SAMUEL BLACK, a British Subject, of the Company's address, 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:- The present invention relates to welt-strips for use in the production of footwear more particularly by the method described and claimed in Specification No 675/54 (Serial No 785,535), the object of the invention being to provide a welt strip element capable of being stitched to an upper along a line extending parallel and comparatively close to the outer edge of the welt strip and of being thereafter turned inwardly so that the major portion thereof lies beneath the upper and the minor portion forms an outwardly extending welt. It will be realised that such a welt strip must be capable of following the curved configuration of the edge of the footwear without wrinkling or buckling and in accordance with the present invention a welt strip is provided for this purpose which is skived near one edge and said edge is also provided with a series of deep serrations wherein both the tips and the recesses of the serrations are of

V-pointed form so that the strip can be readily bent within a plane containing its major axis to follow the curved configuration of the outer edge of the footwear after the welt strip has been turned to a position lying parallel to the under side of the footwear. One construction of welt strip is shown by way of example on the drawing accompanying the Provisional Specification which illustrates the strip in elevation and also in seclPrice 3 s 6 d l tion The welt strip 10 C may be formed from any suitable material which has the characteristics of firmness, flexibility and stitch holding qualities For example it may be formed of leather, one of the plastic materials used in the footwear trade, fabric or bonded fabric, laminated materials, the so-called reconstituted materials or compositions i e bonded leather comminutes which may be mixed with rubber or rubber-like compositions or combinations of the aforesaid materials It is of uniform width throughout and one edge, 10 D, is skived or thinned as indicated at 11 D and said edge is also provided with deep continuous serrations as will be more clearly apparent from the drawing The other edge is left plain. The manner in which the welt strip shown and described may be used in the production of footwear is described and claimed in the aforesaid Specification.

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* GB785537 (A)

Description: GB785537 (A) ? 1957-10-30

Improvements in or relating to transistor circuits

Description of GB785537 (A)

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BE524722 (A) CH318659 (A) DE924328 (C) FR1095001 (A) NL91993 (C) US2870413 (A) BE524722 (A) CH318659 (A) DE924328 (C) FR1095001 (A) NL91993 (C) US2870413 (A) less Translate this text into Tooltip

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PATENT SPECIFICATION Date of Application and filing Complete Specification: Nov 27, 1953, I' F Application made in Netherlands on Dec 1, 1952. Complete Specification Published: Oct 30, 1957. 785,537 No 33002/53. Index at Acceptance:-Class 40 ( 5), M. International Classification:-H 03 d. COMPLETE SPECIFICATION Improvements in or relating to Transistor Circuits We, PHILIPS ELECTRICAL INDUSTRIES Li MITED, of Spencer House, South Place, Finsbury, London, E C 2, a British Company, do hereby declare the invention, for which we -5 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 transistor circuits for demodulating frequency-modulated signals. The invention comprises a frequencydemodulating circuit -embodying a transistor which has at least one emitter electrode, at least one collector electrode, and two base electrodes which are symmetrically connected to the same zone on the transistor, and further embodying means for deriving from a frequency-modulated signal a first oscillation and a second oscillation which differ in phase from one another by an amount which depends on the instantaneous frequency of the frequency-modulated signal, the said first oscillation being applied between a neutral point and the said emitter electrode-while the said second oscillation is applied in opposite phases to the said base electrodes in symmetrical relation to the said neutral point. In order that the invention may be readily carried into effect, embodiments thereof will now be described by way of example with

reference to the accompanying diagrammatic drawing in which:Figure 1 shows a circuit for demodulating a frequency-modulated signal, Figures 2 (a) and 2 (b) show current/time curves for explaining the operation of the circuit shown in Figure 1. Figure 3 represents a modification of the circuit shown in Figure 1; and Figure 4 -shows schematically a pointcontact transistor for use in the circuit shown -lPrice 3 s 6 d l in Figure 1. Figure 1 shows a circuit according to the invention for demodulating a frequency 45 modulated input I F signal which is supplied to a mesh 8 tuned to the central frequency thereof The mesh 8 is closely coupled to an inductance 9 and is coupled to a tuned circuit with approximately critical coupling The 50 voltage V 1 across the inductance 9 constitutes a first oscillation, while the voltage V 2 across the circuit 10 constitutes a second oscillation. The voltage V 1 is applied to the emitter electrode e -and the voltage V, is applied to the 55 two base electrodes bl and b 2 in phase opposition By the intermodulation of these -two signals there is set up between the two base electrodes bl and b, a potential difference which is substantially proportional to the frequency 60 swing of the signal in the mesh 8 and is supplied through -an intermediate-frequency smoothing filter 11 to output terminals 12. Although the voltages V 1 and V 2 are of-the same frequency they differ in phase; hence 65 -mixing occurs as in known frequency-demodulators -such as those described in, for instance, U S A specifications Nos 2,343,263 and 2,231,997. In order to prevent the output oscillation at 70 the terminals 12 from being affected by any amplitude modulation of the input signal, the impedance arm 13 connecting the inductance 9 to the emitter electrode e is tuned to have a comparatively high impedance at the frequen 75 cies of the amplitude modulation which is to be -suppressed but a comparatively low impedance at the signal frequencies. The operation of this circuit depends upon the properties of the emitter-base junction, 80 associated with the voltage-drop along the zone p and with the current-multiplication in the transistor The emitter current and collector current are nearly equal; i,= cie where cc is slightly less than 1; hence i 4 = ccibl(l-cc), and voltage-amplification is effected owing to the high internal resistance of the collector circuit The operation will now be explained more fully with reference to Figures 2 (a) and 2 (b) in which the emitter electrode is assumed to be unbiased, transistor action occurring, however, whenever V 1 or V 2 is positive in relation to the emitter The voltages across. the inductance 9 and mesh 10 are relatively displaced in phase by 90 at the central frequency of the frequency-modulated input signal in

the mesh 8 The currents 4 e, ib 1 and ib 2 then vary with time t in the manner shown in Figure 2 (a) on different scales The directcurrent component of the current (ibi-ib 2), which flows from one base electrode b, to the other base electrode b 2, is zero If the phasedifference between the oscillations across the inductance 9 and mesh 10 is smaller than 900, the curves change to those shown in Figure 2 (b), where the current (bil-ib 2) contains a positive direct-current component corresponding to a positive voltage across the terminals 12. Similarly, a negative potential-difference appears between the terminals 12 if the abovementioned phase-difference exceeds 900 The potential-difference between terminals 12 is consequently a measure of the phase-difference between the above-mentioned oscillations and hence of the frequency swing of the input signal in the mesh 8. On the other hand the D C component of the current ie is a measure of the amplitude of the signal in the mesh 8 so that by stabilizing this current by means of the tuned impedance 13 the output voltage across the terminals 12 is made practically independent of variations of the amplitude in question. Interaction between the oscillations V 1 in the inductance 9 and those V 2 in the mesh 10 would result in an asymmetrical demodulation curve, and hence in undue distortion Such interaction is avoided by arranging that the current component originating from the oscillation in the mesh 10 and flowing through the inductance 9, and that originating from the oscillation in the inductance 9 and flowing in the mesh 10 shall both be zero Coil 9 is accordingly connected to a middle tapping on the mesh 10 so that decoupling ensues from the fact that the currents in the two halves of the coil in mesh 10 are equal and, in relation to coil 9, opposite. It will be seen that the circuit resembles a Foster-Seeley discriminator, the diodes used in that device corresponding to the baseemitter inputs of a transistor tetrode, but the transistor gives amplification not obtainable with diodes, in virtue of the fluctuating potential-gradient between b, and b 2, The circuit shown in Figure 3 is a modification of the circuit shown in Figure 1, wherein the transistor is of a kind described in British Patent Specification No 741,267 and is provided with two collector electrodes c, and c 2 associated with separate p zones in addition to an emitter electrode e and the two base electrodes b, and b With this arrangement an amplified and demodulated oscillation 70 is produced between the output terminals 12, the intermediate-frequency component being smoothed out by the filter between terminals 12 and collector electrodes c, and c 2. Instead of transistors of the junction type, 75 transistors of the

point-contact type and having each two base electrodes may alternatively be used in the circuit shown in Figure 1 Figure 4 is a plan view of such a transistor The two ends of the transistor crystal, the whole of 80 which constitutes a base region, are connected to the two base electrodes b, and b 2 and on the top of the crystal are placed an emitter electrode e and a collector electrode c with the requisitely close spacing, so that the line connecting the 85 contact points of the electrodes e and c extends substantially at right angles to the direction of the electrical field F which is produced in the neighbourhood of the electrodes e and c when a potential difference is set up between 90 the electrodes b, and b

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