AS/NZS 4968.1:2003 pdf free.Heavy-road vehicles – Mechanical coupling between articulated vehicle combinations – Part1:Design criteria and selection requirements for fifth wheel, kingpin and associated equipment.
This Standard sets out the attachment design forces for fifth wheel assembly and equations to determine the required D-value of components for various combinations. This Standard applies to fifth wheel assemblies used with 50 mm, 75 mm and 90 mm kingpins, and associated equipment for articulated vehicle combination, used in heavy road vehicles, B doubles and road trains. in normal use on both sealed and unsealed roads.
3 DEFINITIONS
For the purpose of this Standard, the definitions below apply.
3.1 Axle
One or more shafts, positioned in a line across a vehicle, on which one or more wheels are intended to support the vehicle to move.
3.2 Axle group
A single, tandem, twinsteer, tri, or quad axle group 3.3 B-double
A combination consisting of a prime mover towing two semi-trailers
3.4 Combination
A group of vehicles consisting of a motor vehicle connected to one or more vehicles.
3.5 Converter dolly
A trailer with one axle group or single axle, and a fifth wheel coupling, designed to convert a semi-trailer into a dog trailer.
3.6 Coupler plate
The part of the fifth wheel which houses the closing jaw system that engages the kingpin of the semi-trailer, and which provides a turning base or support for the skid plate of the semitrailer. The coupler plate is mounted on feet which permit limited pivoting about the transverse axis (see Figure 3.1 in AS/NZS 4968.2).
3.7 D-value
A value based upon the dynamic longitudinal force experieiiced by the fifth wheel and kingpin for a particular vehicle combination and load.
3.8 Dog trailer
A trailer (including a trailer consisting ofa semi—trailer and converter dolly) with—
(a) one axle group or single axle at the front that is steered by connection to the towing vehicle by a drabar; and
(b) one axle group or single axle at the rear.
3.9 Fifth wheel
A device fitted to a towing vehicle to permit quick coupling and uncoupling of a semitrailer, provide articulation for the combination, and provide stability and support to the semi-trailer. Where a fifth wheel is specially designed to have a turntable base as an integral part, the term fifth wheel includes that turntable base. It does not include the skid plate and kingpin, which are parts of the semi-trailer.