BRITISH STANDARD BS AU 50 1 4 4b 1992 ISO 4251 5 1992 Incorporating Amendment No 1 to BS AU 50 1 4 4a 1992 (Renumbers the BS as BS AU 50 1 4 4b 1992), not published separately Tyres and wheels — Part[.]
BRITISH STANDARD BS AU 50-1 -4.4b:1 992 ISO 425 -5 : 992 Tyres and wheels — Part : Tyres — Section 4: Agricultural tractor and machine tyres — Subsection 4.4b: Specification for ply rating marked series tyres for log skidders IC S 65 60 ; 83 60 Incorporating Amendment No to BS AU 50-1 -4 4a:1 992 (Renumbers the BS as BS AU 50-1-4 4b: 1992), not published separately BS AU 0-1 -4.4b:1 992 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Automobile Standards Policy Committee (AUE/- ) to Technical Committee AUE/4, upon which the following bodies were represented: Agricultural Engineers’ Association Automobile Association British Industrial Truck Association British Pressure Gauge Manufacturers’ Association British Rubber Manufacturers’ Association Bus and Coach Council Department of Transport Freight Transport Association Institute of Road Transport Engineers (Inc) Motor Cycle Industry’s Association of Great Britain Ltd Motor Industry Research Association National Tyre Distributors’ Association Retread Manufacturers’ Association Road Haulage Association Ltd Royal Automobile Club Society of Motor Manufacturers and Traders Ltd This British Standard, having been prepared under the direction of the Automobile Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on October 992 Amendments issued since publication © BSI 03- 2000 Amd No Date Comments The following BSI references 0363 May 999 Indicated by a sideline in the margin relate to the work on this standard: Committee reference AUE/4 Draft for comment 90/82455 DC ISBN 80 21 1 BS AU 0-1 -4.4b:1 992 Contents Page Committees responsible Inside front cover National foreword ii Scope Normative references Definitions Marking Dimensions and tolerances Tyre load ratings Rims Tubes Table — Tyre sizes, rim width codes and dimensions Table — Basic tyre loads (BTL) and corresponding inflation pressures (IP) Table — Tyre loads at different speeds (load- speed relationship) Table — Approved rim contours List of references © BSI 03- 2000 Inside back cover i BS AU 0-1 -4.4b:1 992 National foreword This Subsection of this Part of BS AU 50, prepared under the direction of the Automobile Standards Policy Committee, is identical with ISO 4251 - 5: 992 Tyres (ply rating marked series) and rims for agricultural tractors and machines — Part 5: Log skidder tyres , published by the International Organization for Standardization (ISO) This edition supersedes BS AU 50- - 4a: 992, which is withdrawn BS AU 50 is issued in four Parts: — Part 1: Tyres; — Part 2: Wheels and rims; — Part 3: Valves; — Part 4: Rim profiles and dimensions ISO 4251 cover requirements for tyres and rims for agricultural tractors and machines Other Parts of ISO 4251 have been implemented as British Standards as Subsections of BS AU 50 as follows: ISO 425 BS AU Part : Tyre designations and dimensions Part : Subsection Part 2: Tyre load ratings Part : Subsection Part 3: Rims Part 4: Subsection Part 4: Tyre classification and nomenclature Part : Subsection Cross-references The Technical Committee has reviewed the provisions of ISO 4223- to which normative reference is made in the text and has decided that they are acceptable for use in conj uction with this standard A British Standard does not purport to include 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 Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages and 2, 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 amendment table on the inside front cover ii © BSI 03- 2000 BS AU -1 -4 b: 992 3.1 S cope This part of ISO 4251 sets out the designation, dimensions, load ratings and rim coordination of ply special design agricultural tyre suitable for forestry rating marked series of log skidder tyres of diagonal application construction Rim dimensions are given in ISO 4251-3 maximum load of total vehicle mass with accessories plus load increases due to log winching The following standards contain provisions which, or grappling loads and mass transfer that is through reference in this text, constitute provisions imposed on an individual tyre due to total radial of this part of ISO 4251 At the time of publication, forces during operation the editions indicated were valid All standards are subject to revision, and parties to agreements based on this part of ISO 4251 are encouraged to The marking of ply rating marked series of tyres for investigate the possibility of applying the most log skidders shall consist of designations of the tyre recent editions of the standards indicated below size and ply rating and the distinctive marking LS; Members of IEC and ISO maintain registers of additional information shall be as specified in currently valid International Standards ISO 4251-1 ISO 4223-1:1989, Definitions of some terms used in logging se rvice tyre 3.2 b asic tyre load for log skidde rs Normative references Marking the tyre industry — Part 1: Pneumatic tyres ISO 4251-1:1992, Tyres (ply rating marked series) and rims for agricultural tractors and machines — Part 1: Tyre designation and dimensions ISO 4251-3:1985, Tyres and rims (existing series) for agricultural tractors and machines — Part 3: Rims D imensions and tolerances Standard sizes, measurement rims, design dimensions of new, diagonal construction log skidder tyres, of both normal and low section height, and maximum tyre dimensions in service shall be as given in Table Tyre load ratings D efinitions For the purposes of this part of ISO 4251, the definitions given in ISO 4223-1 and the following definitions apply Basic tyre loads for log skidder tyres of diagonal construction, and normal and low section height, for a maximum speed of 30 km/h are given in Table The loads given are maximum values and are valid for the inflation pressures indicated Tab le — Tyre siz es, rim width code s and dimensions Dimensions in millimetres D e sign ne w tyre Tyre siz e Me asure me nt rim de signation w id th cod e 18.4 – 26 LS 18.4 – 34 LS 23.1 – 26 LS 24.5 – 32 LS 16 16 20 21 28 L – 26 LS 25 30.5 L – 32 LS 27 S e ctio n width 467 467 587 622 714 775 O ve rall diame te r Normal se ction he ight tyre s 476 679 632 831 Low se ction he ight tyre s 644 847 In se rvice b a Maximum o ve rall Maximum ove rall width diame te r 504 504 634 672 525 728 691 892 771 837 703 909 a Skidder manufacturers should recognize that specialized tyres with deeper tread and corresponding increased overall diameter may be used b Minimum new tyre overall diameter is calculated on the basis of a tolerance of – % on design section height © BSI 03-2000 BS AU 50-1 -4.4b:1 992 Table — Basic tyre loads (BTL) and corresponding inflation pressures (IP) PR Tyre size designation 18.4 – 26 LS 18.4 – 34 LS 23.1 – 26 LS 24.5 – 32 LS BTL PR IP kg BTL kPa 580 920 250 170 170 140 kg PR IP BTL kPa 250 210 495 170 Table — Tyre loads at different speeds (load-speed relationship) 15 25 30 40 BTL kPa IP kg kPa Normal section height tyres 28 L – 26 LS 760 30.5 L – 32 LS 710 6.2 For logging operations with a maximum speed of km/h, tyre loads may be increased to 110 % of the values given in Table with no increase in inflation pressure 6.3 For transport service and operations which not require sustained high torque, the loads at various speeds given in Table apply with no change in inflation pressure km/h IP kg Low section height tyres Maximum speed PR Maximum tyre load a 120 110 100 90 a Expressed as a percentage of the basic tyre loads given in Table 140 140 720 260 285 170 370 170 Tubes Whenever an inner tube is required, it shall be identified by the same designation as the size of the tyre in which it is to be mounted Table — Approved rim contours Tyre size Measurement rim Approved rim designation width code contours 18.4 – 26 LS 18.4 – 34 LS 23.1 – 26 LS 24.5 – 32 LS Normal section height tyres 16 16 20 21 DW 16 A DW 16 A DW 20 A DW 21 A DH 21 Low section height tyres 28 L – 26 LS 25 30.5 L – 32 LS 27 DW 25 A DW 27 A DH 27 Rims 7.1 Rim contours See ISO 4251-3 7.2 Rim coordination In addition to the measurement rim width given in Table 1, the approved rim contours are given in Table for tyres for log skidders with normal and low section height Consult rim and wheel manufacturer for confirmation of the strength of rim/wheel for the intended service © BSI 03-2000 BS AU 0-1 -4.4b:1 992 List of references See national foreword © BSI 03- 000 BS AU 0-1 -4.4b:1 992 ISO 425 -5 : BSI — British Standards Institution 992 BS I is the indep endent national b ody res p ons ib le for p rep aring Britis h S tandards It p res ents the UK view on s tandards in E urop e 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