BS AU 50-1-4.4b:1992 pdf free download.Tyres and wheels — Part 1: Tyres — Section 4: Agricultural tractor and machine tyres — Subsection 4.4b: Specification for ply rating marked series tyres for log skidders.
1 Scope
This part of Iso 4251 sets out the designation, dimensions, load ratings and rim coordination of ply rating marked series of log skidder tyres of diagonal construction.
Rim dimensions are given in ISO 4251-3.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO 4251. At the time of publication, 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 investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
ISO 4223-1:1989, Definitions of some terms used in 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: Runs.
3 Definitions
For the purposes of this part of ISO 4251, the definitions given in ISO 4223-1 and the following definitions apply.
3.1
logging service tyre
special design agricultural tyre suitable for forestry application
3.2
basic tyre load for log skidders maximum load of total vehicle mass with accessories plus load increases due to log winching or grappling loads and mass transfer that is imposed on an individual tyre due to total radial forces during operation
4 Marking
The marking of ply rating marked series of tyres for log skidders shall consist of designations of the tyre size and ply rating and the distinctive marking LS; additional information shall be as specified in
ISO 4251-1.
5 Dimensions 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 1.
6 Tyre load ratings
6.1 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 2.
The loads given are maximum values and are valid
for the inflation pressures indicated.
6.2 For logging operations with a maximum speed of 8 km/h. tyre loads may be increased to 110 % of the values given in Table 2 with no increase in inflation pressure.
6.3 For transport service and operations which do not require sustained high torque, the loads at various speeds given in Table 3 apply with no change in inflation pressure.
7 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 4 for tyres for log skidders with normal and low section height.
Consult rim and wheel manufacturer for confirmation of the strength of rimlwheel for the intended service.
8 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.