1、BRITISH STANDARD BS 4831:1985 ISO 1082:1984 Specification for Shackle type connector units for chain conveyors for mining ISO title: Mining Shackle type connector units for chain conveyors UDC 622.647.222:621.85.055.7BS4831:1985 This British Standard, having been prepared under the directionof the M
2、ining and Quarrying Requisites StandardsCommittee, was published under the authorityofthe Board of BSIandcomes into effect on 31 May 1985 BSI 11-1999 First published May 1972 First revision May 1985 The following BSI references relate to the work on this standard: Committee reference MQE/6 Draft for
3、 comment 82/79441 DC ISBN 0 580 14432 1 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Mining and Quarrying Requisites Standards Committee (MQE/-) to Technical Committee MQE/6, upon which the following bodies were represented: Associati
4、on of British Mining Equipment Companies British Chain Manufacturers Association British Valve Manufacturers Association Ltd. Health and Safety Executive Institution of Mining Engineers National Coal Board Amendments issued since publication Amd. No. Date of issue CommentsBS4831:1985 BSI 11-1999 i C
5、ontents Page Committees responsible Inside front cover National foreword ii 1 Scope and field of application 1 2 References 1 3 Definitions 1 4 Components of connector units 1 5 Sampling and testing 2 6 Inspection procedure 3 Figure Connector unit 4 Table 1 Dimensions of connectors 5 Table 2 Dimensi
6、ons and mechanical properties of the connector bolt and nut 6 Table 3 Mechanical properties of shackle type connectors 6 Publications referred to Inside back coverBS4831:1985 ii BSI 11-1999 National foreword This British Standard has been prepared under the direction of the Mining and Quarrying Requ
7、isites Standards Committee and is identical with ISO1082:1984 “Mining Shackle type connector units for chain conveyors” published by the International Organization for Standardization (ISO). The United Kingdom has taken part in the preparation of the International Standard through Sub-committee2 of
8、Technical Committee82 of the International Organization for Standardization (ISO). This standard supersedes BS4831:1972 which is now withdrawn. Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard without deviation. S
9、ome terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. Wherever
10、 the words “International Standard” appear, referring to this standard, they should be read as “British Standard”. It should be noted that where reference is made in the Figure to an “l” bar leg, this should read “I” bar to indicate the shape of the section. A British Standard does not purport to in
11、clude all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references International Standard Corresponding British Standard ISO/R 147:1
12、960 BS 1610:1964 Methods for the load verification of testing machines (Technically equivalent) ISO 610:1979 BS 2969:1980 Specification for high tensile steel chains (round link) for chain conveyors and coal ploughs (Identical) ISO 5612:1984 BS 6591:1985 Specification for scraper bars for chain conv
13、eyors for mining (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the
14、amendment table on the inside front cover.BS4831:1985 BSI 11-1999 1 1 Scope and field of application This International Standard specifies the requirements for a range of shackle type connector units for use with chain conveyors. Each unit consists of the following components: a) shackle type connec
15、tor; b) connector bolt; c) connector nut. This International Standard is not intended to indicate a complete design, but it gives sufficient detail to ensure dimensional compatibility with chains complying with ISO610 and scraper bars complying with ISO5612. The connector units specified are intende
16、d for use as part of14,18,22,24 and26mm diameter chain assemblies in which the connectors are fitted tightly on to scraper bars. The Figure illustrates the connector; critical dimensions are specified inTable 1. 2 References ISO/R 147, Load calibration of testing machines for tensile testing of stee
17、l. ISO 610, High-tensile steel chains (round link) for chain conveyors and coal ploughs. ISO 5612, Mining Scraper bars for chain conveyors. 3 Definitions For the purpose of this International Standard, the following definitions apply. 3.1 size the nominal size of the chain for which the connector is
18、 made 3.2 test force the specified force to which a sample finished connector unit shall be subjected without exceeding the stated percentage elongation inTable 3 3.3 breaking force the maximum force which a sample finished connector unit withstands during the course of a tensile test to destruction
19、 3.4 percentage elongation the extension expressed as a percentage of the outside length 3.5 processing any treatment of the connector units subsequent to forging; for example heat treatment, machining or surface treatment 3.6 inspector the representative of the purchaser 4 Components of connector u
20、nits 4.1 Shackle type connector 4.1.1 Material The steel used shall be fully killed, of forgeable quality and of a type not liable to embrittlement, including strain age embrittlement. Within these limitations, and unless otherwise specified, it shall be the responsibility of the connector manufactu
21、rer to select the steel so that the finished connector, suitably heat-treated, meets the specified mechanical properties. 4.1.2 Heat treatment Connectors conforming to this International Standard shall be heat treated in the course of manufacture. Heating to an appropriate temperature above the crit
22、ical point (Ac 3 ) of the steel used shall form part of such heat treatment. 4.1.3 Workmanship All finished connectors shall be sound and free from cracks, surface flaws, laminations and other harmful defects. All flashes or fins produced in manufacture shall be removed. 4.1.4 Surface condition Unle
23、ss otherwise agreed between purchaser and manufacturer, connectors shall be supplied unpolished and free from any coating. 4.1.5 Identification marking Where identification marking is applied during forging, the marks shall comply with6.2.1 and be positioned on the connector body so that the mechani
24、cal properties of the connector are unaffected and the marking is not readily removed by abrasion in use. 4.1.6 Dimensions The connector (see the Figure) shall be produced to the dimensions shown inTable 1 for the appropriate size of chain. All other dimensions shall be chosen to ensure correct mati
25、ng between the connector and the associated sprocket, scraper bar and conveyor pan.BS4831:1985 2 BSI 11-1999 4.2 Connector bolt and nut The essential dimensions and mechanical properties of bolts and nuts shall comply with Table 2 and appropriate International Standards. 5 Sampling and testing 5.1 G
26、eneral The dimensions and mechanical properties of connectors shall be as stated inTable 1 andTable 3. The testing procedure shall be as follows. 5.2 Selection of samples Unless otherwise specified by the purchaser, the following sampling arrangements shall apply, but this shall not preclude the ins
27、pector asking for such further samples as he may deem necessary: a) test samples shall be selected at random; they shall be in the same condition as the bulk of the connectors; b) for sampling purposes, the connectors shall be divided into lots, a lot comprising500 connectors; any fraction shall be
28、considered as a complete lot; c) for the dimensional test, five samples shall be taken from each lot; d) for the static tensile test, one sample shall be taken from each lot; e) for the fatigue test, one sample shall be taken from each lot. 5.3 Dimensional test The finished connector dimensions shal
29、l be verified as being in accordance with those specified in Table 1. 5.4 Static tensile test 5.4.1 Test conditions For the purpose of the test, the finished connector shall be assembled with a) a suitable spacer; b) a connector bolt and nut of the type described inTable 2 of this specification; c)
30、two lengths of chain of the appropriate size in ISO610 in the same grade or better than the connector under test and to suit the requirements of the testing machine. Alternatively special anchorages, with dimensions corresponding to those of the appropriate size of chain, may be used to anchor the c
31、onnector in the testing machine. The spacer shall have the same profile as the scraper bar that is to be used with the connector. With the spacer in position the bolt/nut shall be tightened to the relevant value of torque given inTable 2. The type and accuracy of the testing machine shall be in acco
32、rdance with class1 of ISO/R147 or equivalent national standard. The testing machine shall be used only within its appropriate range as shown by the test certificate. 5.4.2 Elongation at test force The connector unit shall be subjected to a force equal to half of the test force stated inTable 3. The
33、force shall then be reduced to the setting force stated inTable 3 and the outside length of the connector (C inTable 1) measured. The force shall then be increased, at a rate of approximately20MPa/s 20(N/mm 2 )/s, to the test force specified inTable 3 and the outside length of the connector again me
34、asured. The total elongation so determined shall not exceed the relevant percentage stated inTable 3. 5.4.3 Breaking force Following application of the test force, the force shall then be increased further until the sample breaks. The ultimate breaking force determined by the test shall be not less
35、than the appropriate value stated inTable 3. If, during the test, the sample does not reach the ultimate breaking force stated inTable 3, because of prior failure of the connector bolt or nut, the test is void and shall be repeated on another sample. 5.4.4 Permanent elongation after fracture After t
36、he test break, the broken parts of the connector shall be fitted together and the outside length of the connector (C inTable 1) measured. The permanent elongation determined by the test shall be not less than the minimum percentage given inTable 3. 5.5 Fatigue test 5.5.1 General The fatigue test is
37、not mandatory. It is an optional test which may be used as an additional acceptance criterion subject to agreement between purchaser and manufacturer at the time of order. 5.5.2 Description of test The test involves subjecting a connector/chain assembly, as previously described in5.4.1, to repeated
38、forces (between a lower and an upper limit, seeTable 3) at a given frequency. The number of cycles sustained before the sample breaks constitutes the fatigue resistance (or endurance) of the sample. 5.5.3 Conditions of test Fatigue tests should be performed under the following conditions.BS4831:1985
39、 BSI 11-1999 3 5.5.3.1 Testing machine The type and accuracy of the testing machine shall be suitable for applying the forces specified in Table 3. The machine shall be calibrated statically, where appropriate, in accordance with class1 of ISO/R147 or an equivalent national standard. Compensation fo
40、r dynamic effects should not be based on calculations, but the actual forces on the test piece should be checked occasionally by some electrical measuring device that can be mounted on the machine in series with the sample. 5.5.3.2 Frequency of force application The frequency of force application sh
41、all be not less than200cycles per minute and not greater than1000 cycles per minute. In case of dispute check tests shall be carried out at500cyclesperminute. 5.5.3.3 Criteria of acceptance Each sample tested shall be deemed satisfactory if its fatigue resistance/endurance is not less than40000cycle
42、s. If a result is less than40000cycles, two further samples shall be subjected to the same test; both shall have an endurance of not less than40000cycles. The purchaser and manufacturer may, by agreement, determine the acceptance level for fatigue resistance by using a statistical method as outlined
43、 inAnnexE of ISO610. 6 Inspection procedure 6.1 Acceptance A connector lot shall be deemed to comply with this International Standard if each of the samples taken from the lot fulfils all the specified test requirements. Should any of the samples fail to meet any one of the specified tests, two furt
44、her samples shall be selected from the same lot. If both these additional samples meet all the specified tests, the lot shall be deemed to comply with this International Standard. Should either of the two further samples fail any one of the specified tests, the connector lot shall be rejected. 6.2 M
45、arking 6.2.1 Identification marking All finished connectors shall be legibly marked to indicate the manufacturer and, by agreement between the purchaser and the manufacturer, any other relevant information. 6.2.2 Inspection marking Provided all specified tests are satisfactory and a lot has been acc
46、epted, the inspector shall signify his acceptance. The precise extent and nature of the inspection marking to be used shall be subject to agreement between the purchaser and the manufacturer. 6.3 Test certificate At the option of the purchaser, the manufacturer shall supply a representative certific
47、ate(s) of test and examination with every consignment of connector units supplied as conforming to this International Standard; when so agreed between the purchaser and the manufacturer, identification of the cast number of the steel shall be stated. This shall also apply in instances where connecto
48、r units are supplied as part of a complete conveyor chain assembly. The certificate shall be signed by the manufacturer and by the inspector if he witnessed the inspection test. 6.4 General inspection For the purpose of witnessing the tests and inspecting the testing machines and methods of examinat
49、ion, the inspector shall be given access to the relevant parts of the works of the manufacturer at all reasonable times. BS4831:1985 4 BSI 11-1999 NOTEThe connector illustrated is a short leg connector. Figure Connector unitBS 4831:1985 BSI 11-1999 5 Table 1 Dimensions of connectors Dimensions and tolerances in millimetres Size and pitch of chain Connector pitch Material diameter Length Chain centre to outside pad Chain centre to hole centre Pad Outer radius Hole diameter Bolt diameter Inner radius Leg height Hole centre from datum Leg width Chamfer loca
