ELEVATORSafety Buffers

LEADING THE WORLD IN ENERGY ABSORPTION

GBR

KeepingPeople SafeOleo leads the world in energy absorption inmany critical applications, often as the lastline of protection for people and equipment.

Every day millions of people around theworld rely on Oleo to provide their safety.

It is our responsibility to ensure all interna-tional standards for the industries we supplyare adhered to, but we strive for more thanthat – to enable our partners to provide thesafest energy absorption solutions remainsa core principle.

Our mission is clearly and simply to keeppeople safe.

1

The Elevator IndustryThe elevator industry is constantly developing all overthe world, from small passenger lifts to high massfreight elevators, low speed applications covering afew floors to ultra high speed systems moving swiftly tothe penthouse.

Elevators form the core of the transport system formany modern structures and with building sizes andpassenger volumes increasing, the need for elevatorsto handle more people, travelling over increasingdistances and moving at higher speeds, whilstensuring safety is maintained at the highest levels hasnever been greater.

Oleo elevator buffers are designed to protect peopleand equipment from forces generated by an impactresulting from equipment failure or operator error.

Irrespective of your requirements, Oleo has a completerange of globally certified buffers to suit elevatorsoperating with wide mass ranges at almost any speed.By choosing Oleo, your elevator system can benefitfrom ultimate protection with buffers that offerlightweight construction, extreme durability andminimum life-cycle costs.

OLEO PROVIDES ELEVATOR PASSENGER SAFETY IN THE WORLDS MOST ICONIC BUILDINGS

2

SimulationComplex mathematical algorithms developed by ourdedicated simulations team are used in combination with FEAmodelling and CFD software enabling Oleo to developproducts with optimised performance characteristics thatensure maximum passenger safety. Moreover, our ability tosimulate buffer performance in conjunction with otherelevator components allows us to work closely with elevatormanufacturers to ensure the ultimate level of protection forequipment and passengers.

ELEVATOR SIMULATION TOOL

ConsultancyConsultancy is a growing part of our business. We regularlyundertake projects to produce bespoke energy absorptionsolutions for customers including design, analysis andtesting services.

Our experience, simulation and test facilities enable Oleo tooffer partnership opportunities for elevator manufacturers whowish to benefit from our profound knowledge and expertise.

DESIGN AND ANALYSIS

Research and DevelopmentOur purpose is to provide the highest levels of protection inorder to keep people safe. We pride ourselves on beinginnovative in response to both industry standards andcustomer demands. Continuous investment in research anddevelopment, state of the art technology and modernmanufacturing processes has made Oleo leading experts inenergy absorption.

All buffers are tested and validated internally prior toobtaining accreditation from the relevant standardsauthorities. Our independent test facility is accredited toISO 17025 and offers state of the art test rigs and diagnosticequipment to ensure the most accurate performance datais obtained during arduous test programmes.

OLEO TEST TOWER,UK HEADQUARTERS

3

Global CertificationDocumentation and certification form an important part ofcustomers’ requirements in the elevator industry. To make lifesimple Oleo products are available with all the necessarydocuments required to ensure a smooth transition from orderto installation.

For applications in Europe, North America, China, Russia orKorea, Oleo can offer certified products to meet your needs.

WORLDWIDE COMPLIANCE

E-commerceConvenience at your fingertips – placing orders for elevatorbuffers has never been easier!

Our online configurator allows the selection of the ideal unitto suit your requirements and the ability to purchase bufferswith a quick delivery.

EASY, ONLINE ORDERING

Global PresenceThe elevator industry is a global business, but a localpresence is required to ensure the highest levels of customersatisfaction and reduce the total elevator cost.

Oleo has manufacturing sites and distribution centres invarious strategic locations around the world to ensureproducts are available quickly and at competitive prices.

GLOBAL PRESENCE, LOCAL SUPPORT

4

CONVENIENCE AT YOUR FINGERTIPS

“Products selected using Oleo’sConfigurator can be purchasedimmediately using our E-Commerce platform on theOleo website.

Giving you what you want, whenyou want it.

5

Elevator SafetyElevator buffers are safety devices which arerequired to be mounted at the base of an elevatorshaft underneath the elevator car or counterweight.As with any safety device, elevator buffers have tomeet detailed specifications in order to satisfyinternational standards.

Since the very early days of elevators, a variety ofsafety systems have been employed to ensure that theelevator will not free fall. The purpose of elevatorbuffers is to provide protection against themalfunction of an elevator control system resulting inthe lift continuing to travel past the lowest stop to thebase of the elevator shaft.

The most important aspect of the global standards isthe manner in which the buffers must bring animpacting elevator car to rest. There are differencesbetween the various technical standards however allemploy the same basic performance criteria.

Although freefall is not a realistic event for anelevator, the specification and code requirements arebased on the assumption of freefall as this is worstcase scenario.

Our hydraulic buffers are classified as ‘energy dissipationbuffers’ and they dissipate the energy from an impactin the form of heat during the travel of the buffer. Thistype of buffer can be used for all rated speeds, but aregenerally used for speeds of 1.0m/s or over.

The buffers are specified for installation in accordancewith the rated speed and mass of the elevator.

Buffer performance criteria – energy dissipation buffers

Performance criteria in all the standards is governedby two underlying rules which state that the buffermust arrest a freefalling mass travelling at 115% of therated speed of the elevator:

• With an average deceleration not exceeding 1g.

• Without exceeding a deceleration of 2.5g for a timeperiod greater than 0.04 seconds.

A further requirement states that the buffer stroke mustbe at least as great as the free fall distance required toreach 115% of the rated elevator velocity. It is thisrequirement that dictates the stroke and subsequentlythe installation height of elevator buffers. Due tocustomer demands, Oleo elevator buffers do notdeviate far from the minimum stroke requirement.

KEEPING PEOPLE SAFE

6

Oleo Buffer PerformanceThe minimum stroke for an elevator buffer is specified(within EN81-20 and ASME A17.1), as the necessarydistance to bring an impacting mass, travelling at 115%of the buffer's rated speed, to rest with a uniformdeceleration of 1g. However, this is only true if the bufferexerts a constant retardation force over its entire stroke.

A hydraulic buffer can be designed to closely matchthis idealised performance. This is achieved by precisecontrol of hydraulic oil flow across an orificethroughout the buffer stroke. However, this can only beachieved for one specific impact mass. The same

performance is not achievable for the range of elevatormasses that are encountered in the real world wherethe elevator car mass varies with passenger load.

In the elevator application, where there is a need toprotect passenger safety, it is important to try tominimise the deceleration experienced duringstopping. This can be easily resolved when theelevator is fully loaded but at low loads the sameretardation force will slow the elevator more quicklyand therefore initially result in higher decelerationfor the passenger.

THE BURJ KHALIFA TOWERS OVER DOWNTOWN DUBAI

Fully loaded elevatorElevator Speed 3m/sMaximum Mass 5500kg Oleo MLB25 Alternative SupplierThe performance of the Oleo and the alternative supplier ’s elevator buffer is similar.

Lightly loaded elevatorElevator Speed 3m/sMinimum Mass 450kg Oleo MLB25 Alternative SupplierThe performance of the Oleo buffer design shows its benefits with a much lower peakdeceleration force of 2.6g in comparison to 10g for the alternative supplier ’s elevator buffer.

0.05 0.1 0.15 0.2 0.25 0.3 0.350

10.00

9.0

8.0

7.0

6.0

5.0

4.0

3.0

2.0

1.0

0.0

-1.0

G F

orce

Time in seconds

7

The graph above compares test data from twohydraulic buffers that both meet the elevator codespecification requirement being used to stop anelevator car travelling at 3m/s. This shows the g-forcethat will be experienced by passengers travelling infully and lightly loaded conditions.

Oleo units incorporate special metering designs thatallow the energy to be dissipated in a controlled fashion.

In both load conditions both buffers keep the averagedeceleration below 1g and do not allow 2.5g for morethan 40 milliseconds and therefore areboth fully compliant with elevator codespecification requirements.

The limiting of peak deceleration force isnot required by any elevator code orindustry specification.

Alternative buffers achieve the average 1gcriterion by an initial period of highdeceleration followed by extending thefinal stages as the elevator is coming torest. The other key elevator bufferspecification requires that passengers donot experience more than 2.5g for morethan 40 milliseconds but within thisperiod g-forces are not limited (for energydissipation buffers). However, asillustrated above, in certain conditions

very high instantaneous g-forces occur and the effectson elevator passengers are unproven.

Oleo has an overall passenger safety aware approachand seeks to avoid the passenger discomfort that mayarise from instantaneous deceleration that may evenexceed 10g in some circumstances. Many years ofin-house testing and the development of mathematicalalgorithms that accurately simulate the performance ofhydraulic buffers enable Oleo to provide buffers withunsurpassed energy absorption performance.

Oleo refine the metering design to ensure energy is absorbed evenly through an impact.

Plunger

Gas spring

Mechanical spring

Metering tube

Passenger/Residential ElevatorsPassenger elevators are commonlyfound in low rise residential buildings,normally operating at low speed withlow passenger loads.

Elevators operating in residentialbuildings often transport very fewpassengers meaning the performanceof the safety devices at low mass iscritical. We design our buffers aroundthe concept of protecting theequipment in an emergency situation,irrespective of mass, keeping g-forcesto a minimum and ensuring optimumpassenger safety.

Express ElevatorsWith buildings getting ever taller,express elevators are in increasingdemand. These elevators aredesigned to move people quicklyfrom the ground floor directly to thesky lobby, observation deck orpenthouse apartment.

In recent years the industry has seenhuge leaps in the velocity of theseelevators and Oleo has beeninvolved in enabling this trend byoffering ultra high speed, telescopicbuffer technology.

TYPICAL PASSENGER ELEVATOR

ONE WORLD TRADE CENTER

28

Commercial ElevatorsService elevators are primarily found in commercialbuildings such as office and mixed use structures,industrial and large residental buildings.

They are similar in design to passenger elevators withregard to ride comfort but need to operate at highercapacities and often faster speeds. Service elevators canhave more than one elevator car working in a singleshaft to improve people flow through a large building,thus increasing the working mass of a single shaft.

Shopping malls, airports, stadiums, office blocks andconvention centres are all typical locations to findservice elevators, where it is essential to move largeamounts of people quickly and efficiently.

Oleo has a full range of buffers covering all the speedand load requirements of service elevators.

9

A TYPICAL COMMERCIAL ELEVATOR USED IN HOSPITALS

Freight/Service ElevatorsFreight elevators are typicallyheavy duty elevators, designedfor very high masses, meaningthey are strong in structure,moving at slow speed.Primarily these elevators areused in commercial buildingsincluding offices, retail, hotel,public transportation andairport facilities.

Oleo elevator buffers areemployed as safety devices tolimit the damage to stock andfreight being carried in theseelevators, should there be asystem malfunction or failure.

SERVICE ELEVATOR IN A HOTEL

10

Vehicle ElevatorsVehicle elevators are fast becoming apopular choice in heavily populatedareas and high end residentialcomplexes.

The lifts are designed to movevehicles safely and efficiently. Onceagain, due to the potential massesand speeds involved, Oleo buffers areoften considered the ideal choice forthis application.

For years Oleo has offered theultimate protection for elevatorpassengers and we now do the samefor their prize possessions!

AUTOMATED CAR PARKING SYSTEM

1 1

ModernisationAfter many years in operation your elevator mayrequire replacing or modernising. This can be achallenging process to install a new elevator systemwhich has to satisfy the latest legal requirements whilstincreasing carrying capacity, and improving comfortand efficiency at higher speeds.

Oleo can help you by offering solutions to replace yourcurrent buffers in order to allow improved speed andcapacity of the lifts, helping the end customer toincrease the efficiency of people flow in their building.

UPGRADES AND REFURBISHMENT

12

Special ApplicationsThere are, of course, many other applications whereexternal or non–standard requirements have to beconsidered and these have a significant bearing onthe design and potential performance of the buffer.

In the case of some drop tower rides, Oleo elevatorbuffers are used in an emergency event should theride fail during normal operation, in which case it isable to absorb this extra energy in the samecontrolled manner as an everyday elevator.

Oleo is also able to customise designs in order tomeet extremely aggressive service conditions.Examples include the “explosion-proof” and “outdoor”specifications which are both non-standard buffersthat incorporate specially customised parts in order tomeet the demands of their intended application.

TOWER OF TERROR

Some examples of special applications includeamusement rides, outdoor industrial applications,marine vessels and the mining industry.

Typically, where harsher environmental conditionshave to be considered for the elevator design andits components.

MARINE VESSELS

INDUSTRIAL APPLICATIONS

OLEO INTERNATIONALGrovelandsLongford RoadExhallCoventryUnited KingdomCV7 9NEE sales@oleo.co.ukT +44 (0)24 7664 5555F +44 (0)24 7664 5900W oleo.co.uk

Oleo International is a division of T A Savery and Co Limited,whose ultimate parent is Brigam Limited. T A Savery and CoLimited is a company incorporated in England and Wales undercompany number 00272170 and whose registered office is atGrovelands, Longford Road, Exhall, Coventry, CV7 9NE, UK

OLEO BUFFERS INDIA PVT. LTD.Plot No. 32 and 33KIADB Hi-Tech Hardware Park7th Main RoadMahadevakodigehalliBengaluruKarnataka – 562149IndiaE indiasales@oleo.co.ukT +91 961 132 8249W oleo.co.in

OLEO INTERNATIONAL GMBHHildesheimerstr. 331188 Holle/GrasdorfE sales@oleo.com.deT +49 (0) 5062 9657 - 635F +49 (0) 5062 9657 – 638W oleo.com.de

OLEO BUFFERS SHANGHAI COMPANY LTDPlant A15No. 3802 Shengang RoadSongjiangShanghaiE sales@oleo.cnT +86 21 6776 0688F +86 21 6776 0689W oleo.cn

OLEO INC.Agility ATL3505 Naturally Fresh BoulevardAtlanta GA 30349United States of AmericaE sales@oleoinc.comF 404-806-3698W oleoinc.com

Issue 6 – September 2017

LEADING THE WORLD IN ENERGY ABSORPTION