AS 4177.2-2004 pdf free.Caravan And Light Trailer Towing Components – Part2:50 Mm Towballs.
This Standard is Part 2 of AS 41 77. Caravan and light trailer towing components, which is published in Parts as follows:
Part 1: Towbars and towing brackets
Part 2: 50 mm towballs (this Standard)
Part 3: Coupling body for ball couplings
Part 4: Safety chains up to 3500 kg capacity
Part 5: Electrical connectors
This Standard is for towballs, including those complying with ISO 1103:1996, Road vehicles—Coup/mg halls ftr caravans and light traikrs—Dimensions, and ISO 3853: I 994, Road vehicles—Towing vehicle coup/lug device to tow caravans or light trailers— Mechanical sI rengi Ii test.
The objective of this Standard is to provide manufacturers with design dimensions of 50 mm towballs for towing vehicles of tip to 5 t towing vehicle mass, intended for towing trailers and caravans up to 3.5 t aggregate trailer mass, for use on public roads.
In this revision, the material specification which allowed compliance with a performance criteria without having to conduct static or dynamic test, has been deleted.
Also in this revision, this Standard limits the use of the towball to vehicles with a towing vehicle mass up to 5 t.
This Standard specifies requirements for towballs for towing vehicles of up to 5 t towing vehicle mass. The towballs are intended for towing trailers and caravans of up to 3.5 t aggregate trailer mass, for use on public roads.
The method of determining the static strength of a shank-type towball is given in Appendix A and the dynamic strength of a towball is given in Appendix B.
NOTES:
1 Towbars and coupling bodies are specified in AS 4177.1 and AS 4177.3 respectively.
2 Requirements for off-road applications are beyond the scope of this Standard.
3 Requirements for shank-type 50 mm towballs only are specified.
4 Towing bracket and towballs complying with ISO 1103 and ISO 3853 are also acceptable.
3 DEFINITIONS
For the purpose of this Standard, the definitions below apply.
3.1 Aggregate trailer mass
The total mass of the laden trailer when carrying the maximum load recommended by the manufacturer. This includes any mass imposed on the towing vehicle when the combination vehicle is resting on a horizontal supporting plane.
3.2 Ball coupling
A coupling comprising a towball and a complementary coupling body.