1、Unit Handling ConveyorsSLAT CONVEYORSCEMASTANDARDNO. 405-2003ISBN 978-1-891171-33-8Conveyor EquipmentManufacturers AssociationANSI / CEMA 405-2003 (R2009)Reaffirmation of ANSI /CEMA 405-2003( Approved January 22, 2009)SAFETY NOTICEThe Conveyor Equipment Manufacturers Association has developed Indust
2、ry Standard Safety Labelsfor use on the conveying equipment of its member companies.The purpose of the labels is to identify common and uncommon hazards, conditions, and unsafepractices which can injure, or cause the death of, the unwary or inattentive person who is workingat or around conveying equ
3、ipment.The labels are available for sale to member companies and non-member companies.A full description of the labels, their purpose, and guidelines on where to place the labels on typicalequipment, has been published in CEMAs Safety Label Brochure No. 201. The Brochure is availablefor purchase by
4、members and non-members of the Association. Safety Labels and Safety LabelPlacement Guidelines, originally published in the Brochure, are also available free on the CEMAWeb Site at http:/www.cemanet.org/CEMA_Safety_Pg.htmPLEASE NOTE: Should any of the safety labels supplied by the equipment manufact
5、urer becomeunreadable for any reason, the equipment USER is then responsible for replacement and locationof these safety labels.Replacement labels and placement guidelines can be obtained by contacting your equipmentsupplier or CEMA.For Information on Company Membershipvisit the CEMA Web Site athttp
6、:/www.cemanet.orgConveyorChainCEMA ORGANIZATIONAL CHARTControls PalletizersMeet in March and/or SeptemberConferenceStrategic PlanningInsuranceMeetingsMarketing / MembershipStatisticsFinance and BudgetPast PresidentsBulk HandlingSectionCommitteesUnit HandlingSectionEngineering ConferenceConveyor Chai
7、nPerformance TerminologyUnit Handling StandardsIdlersPulleysBeltSystemsScrewConveyorsBeltManualAccessoriesSafety ControlsTerms andDefinitionsInternationalStandardsMeets Each JuneScrewConveyorsBulk HandlingComponentsand SystemsGeneral Bulk Handling SectionBulkAccessoriesUnit Handling Conveying Sectio
8、nCOMMITTEES BOARD OF DIRECTORS OFFICERSDISCLAIMERThe information provided in this document is advisory only. These recommendations areprovided by CEMA in the interest of promoting safety in the work place. Theserecommendations are general in nature and are not intended as a substitute for a thorough
9、safety program. Users should seek the advise, supervision or consultation of qualifiedengineers or other safety professionals.Any use of this document, the information contained herein, or any other CEMA publicationmay only be made with the agreement and understanding that the user and the userscomp
10、any assume full responsibility for the design, safety, specifications, suitability andadequacy of the system component, or mechanical or electrical device designed ormanufactured using this information.The user and the users company understand and agree that CEMA, its member companies,its officers,
11、agents and employees shall not be liable in any manner under any theory ofliability for the user or users reliance on these recommendations.The users and the users company agree to release, hold harmless and indemnify CEMA,its member companies, successors, assigns, officers, agents and employees fro
12、m anyand all claims of liability, costs, fees (including attorneys fees), or damages arising in anyway out of the use of this information.CEMA and its member companies, successors, assigns, officers, agents and employeesmake no representations or warranties whatsoever, either express or implied, abo
13、ut theinformation contained in this document, including, but not limited to, representations orwarranties that the information and recommendations contained herein conform to anyfederal, state or local laws, regulations, guidelines or ordinances.iFOREWORDSlat conveyors are used for the controlled mo
14、vement of a great variety of regular or irregular shapedcommodities. The conveyor may be level, inclined, declined, or curved, limited only by the stability of thecommodity, the frictional relation of the slats and the commodity, and the strength of the conveyor ele-ments. Slat conveyors can be oper
15、ated at the speed best suited for the work being performed. They arefrequently used for conveying commodities through assembly and testing operations. Their use simplifiesthe coordination of varied operations.The purpose of this work is to establish minimum standards for use in manufacturing and app
16、lying unithandling slat conveyors.For additional information relating to definitions and selection of common components, see the latest edi-tion of the following publications: CEMA Standard No. 102, Conveyor Terms and Definitions; CEMA Stan-dard No. 401, Roller Conveyors - Non Powered; CEMA Standard
17、 No. 402, Belt Conveyors; CEMA Stan-dard No. 403, Belt Driven Live Roller Conveyors; CEMA Standard No. 404, Chain Driven Live Roller Con-veyors; and CEMA Standard No. 406, Lineshaft Driven Live Roller Conveyors.The illustrations throughout this book are schematic in nature and represent the general
18、nature of a par-ticular device. The illustrations are not intended to represent the recommended safety configurations sinceguarding has been omitted to permit clarity in showing the operational characteristics of the device. Referto the current editions of ANSI/ASME B20.1, Safety Standard for Convey
19、ors and Related Equipment;ANSI/ASME B15.1, Safety Standard for Mechanical Power Transmission Apparatus; and ANSI Z244.1,American National Safety Standards for Lockout/Tagout of Energy Sources - Minimum Safety Require-ments; Title 29, Code of Federal Regulations (29 C.F.R.) Part 1910.147, The Control
20、 of Hazardous Energy(lockout/tagout); Title 29, Code of Federal Regulations (29 C.F.R.) Part 1910 Subpart O, Machinery andMachine Guarding. Consult ASME or ANSI for the latest editions.CONVEYOR EQUIPMENT MANUFACTURERS ASSOCIATION6724 Lone Oak BlvdNaples, Florida 34109Web Site: http:/www.cemanet.orgS
21、tandard No. 405 - Copyright 2009Printed in the U.S.A.ISBN 978-1-891171-33-8Section Page PDFDEFINITIONS 1 1 5APPLICATIONS 2 2 6TECHNICAL DATA 3 3 9TABLE OF CONTENTSNote - CEMA Has Reaffirmed the 2003 Edition.This 2009 Edition is Identical to the 2003 EditionSUMMARY OF CHANGES IN 2003 EDITION All illu
22、strations have been redrawn. Foreword has been updated to include new information and new Safety References. A Safety Notice regarding Industry Standard Safety Labels has been added. Terms and Definitions have been modified to conform with ANSI/CEMA 102: Conveyor Termsand Definitions. Chart 1 “Shaft
23、s for Combined Tension and Bending“ has been expanded to cover morecombinations of moment. Additional clarification in the section on “Selecting Chains and Sprockets for Conveyor Service“. “Note“ added to Table 5 “Service Factors“.iiCEMA Standard No. 405-2003 (R2009)Reviewed by theUnit Handling Sect
24、ionof theCEMA Engineering ConferenceSection 1DEFINITIONSFor general definitions, see also latest edition of ANSI/CEMA 102, Conveyor Terms and Definitions.Chain - A series of links pivotaIly joined together to form a medium for conveying or transmitting motion,with provisions for attaching the slats.
25、Conveyor Length - Length center to center of sprockets as measured at the conveying surface.Conveyor Width - The length of the slat. When auxiliary guards are required, the distance between theguards should be specified.Drive - An assembly of the necessary structural, mechanical, and electrical part
26、s which provide motivepower for a conveyor.Frame - The structure which supports the machinery components of the conveyor.Grade (Slope) - The rate of incline or decline in terms of degrees from the horizontal; percent of rise to thehorizontal distance; or inches of vertical rise per foot of horizonta
27、l projection.Intermediate Frame - The structural track and supports over which the chain and slats travel.Slat Conveyor - A conveyor employing one or more endless chains to which non-overlapping, non-inter-locking, spaced slats are attached. Only dual strand slat conveyors are considered in this sta
28、ndard.Sprocket - A wheel with suitably shaped and spaced cogs or teeth to engage with the links of a chain.Take-Up - An assembly of the necessary structural and mechanical parts which provides the means toadjust the length of the conveyor to compensate for chain wear or other causes.Vertical Curves
29、- Those portions of a conveyor partly horizontal and partly inclined, or at two differentangles of inclination connected by a radius; a section of track bent in the desired curve to change thedirection of a conveyor in a vertical plane.12Section 2APPLICATIONSlat conveyors are used primarily for hand
30、ling commodities of such nature or weight as would make othertypes of conveyors unsuitable. For example, if a belt conveyor is suitable for conveying a certain kind ofcommodity, it might not be satisfactory for diverting a commodity with an abrasive surface, protruding nailheads, or anything which m
31、ight damage the belt.Slat conveyors are frequently used in various assembly operations, special fixtures being attached directlyto the slats. Special features such as turntable assemblies can be applied. Shaped slats are also availablefor the handling of cylindrical objects.Slat conveyors can be lev
32、el or inclined, declined or curved, or a combination of any of these. The declinedtype is furnished with or without cleats as conditions dictate. Cleats are used on the main surface of theconveyor to prevent sliding of commodities when the degree of grade is greater than an uncleated conveyorwill ha
33、ndle. The average wood box will travel on a wood slat without cleats at a grade of 12 degreesmaximum. The handling of average metal commodities should be confined to a 9 degree grade maximumusing wood slats. The grade of a metal slat conveyor for handling any commodities having a metal conveyingsurf
34、ace should be established by test or prior knowledge.When cleats are used, there is practically no limit to the steepness of the conveyor; but there are factorswhich make cleated units undesirable. Special care must be exercised to load them automatically. Theconnection between conveyors at either e
35、nd of the slat conveyor is complicated because additional spacemust be provided to clear the cleats, and additional space may affect the minimum size commodity whichwill transfer satisfactorily.When commodities overhang the ends of the slats or have to be pulled over the side of the conveyor, it isn
36、ecessary that the top of slats be above the framework.On level to inclined and declined to level conveyors, beveling of the slats may be required to eliminatepinching.Abrasive Carborundum surface slats may be satisfactory for oil drums or metal containers at slopes of 12degrees. Such slats do not ha
37、ve the life of the cleated design nor the disadvantages of the same.The handling of small commodities over the receiving and discharge ends of slat conveyors must alwaysbe given careful attention. A small box might transfer satisfactorily when in one position but not another.Back-travel of inclined
38、conveyors when stopped under load is overcome by use of motor brakes, anti-reversing devices or self-locking gears. Simple ratchets contacting the chain are satisfactory on inclinedunits but are not suitable on declined or reversible conveyors.Roller slat conveyors consist of rollers instead of wood
39、 or steel slats mounted between the chains andshould provide at least three rollers under the shortest length of commodity. Roller slat conveyors willpermit stoppage of a line of commodities without stopping the conveyor. The rollers revolve under thestopped commodities.Roller slat conveyors are sui
40、table for diverting and for conveying on slight inclines. In either case, strips arepositioned underneath the rollers to provide positive rotation and increased speed, thus permitting divertingand negotiation of incline.The use of strips increases the velocity of the commodity to twice the conveyors
41、peed. The maximum grade is approximately 6 degrees or 1 inches per foot.3There are many special purpose slat conveyors made for diverting, dividing, or combining loads. However,most such construction is proprietary or patented.Limitations as to length, width, and loading of slat conveyors are not qu
42、ite so critical as for other types of unithandling conveyors.Lengths are flexible and are dependent upon the strength of the chain selected. Chains are usually of theroller type for less chain pull.Widths are equally flexible, however, seldom less than 12“ for the double strand chain construction. B
43、yusing multiple idler roller supports attached to the slat, for breaking the span between the side chains,widths up to several feet are possible. Single chains are not often used. When they are used the load isgenerally supported by wheels attached at each end of the slat. When two strands of chain
44、are used, theload is usually carried by slats supported by the chain rollers riding upon angle or T-rail track.Speeds can be that required to suit conditions. Extremely slow speeds for assembly operations can bearranged, and variable speed drive units are also available.Maximum speed is usually dete
45、rmined by the chain pitch, the noise level that can be tolerated, and themethod of transfer from the conveyor. The pitch diameter of the driving sprocket is an important factor. Fordetermination of speed with selected sprocket and pitch combination see table 2 on page 7.Minimum speeds are generally
46、indicated by a condition known as surge. At speeds below 5 F.P.M., shortpitch chains and sprockets of 12 or more teeth are suggested. Special compensating sprockets will tend tominimize pulsation.Maximum loading is determined by the strength of the chain and the unit loading which the individual cha
47、inrollers will carry without undue wear. Unit loads of several thousand pounds are not uncommon and must besupported by enough slats to keep the chain loading below the recommended values.Figure 11/3 LengthVertical Line ThruCenter of GravityDesired Angleof Incline LineCenter of Gravity(Not Necessari
48、ly TheGeometrical Center)LengthHeight4Grade - The maximum angle of incline or decline is limited by the following principal factors:1. The proportions of the commodities handled, (see Figure 1).2. Resistance to slippage of the commodities on the slat surface.3. Speed and vibration of the conveyor.4.
49、 On critical inclines powered feeds may be required.NOTES RELATIVE TO DIAGRAMThe relationship of the height of the package to its base length is defined in above diagram. A safe ruleis to make the grade such that a perpendicular line drawn through the center of gravity of the packagewill fall within the middle one-third of its base length. Assuming that the package is of uniform densitythroughout its volume, the maximum grade angle can be calculated thus:Tangent of the maximum grade angle =length3 x heightUse less grade angle for safety.Section 3TECHNICAL DATASafety
