Abstract: A road vehicle is disclosed having a bumper assembly fitted to the rear end of the vehicle. The bumper assembly includes a beam extending across the rear end of the vehicle and supported by an arm from the vehicle so that the beam is displaceable from a rest position in a direction towards or beneath the vehicle in the event of contact with an obstacle.

Abstract: An underrun guard for a road transport vehicle is disclosed comprising a beam intended to be supported across the rear of the vehicle by a support mechanism which yields under a force which would otherwise be likely to cause damage to the vehicle. The support mechanism comprises at least one first for attachment to the beam and at least one second plate for attachment to the vehicle, and a clamping member for clamping the plates together while permitting relative sliding movement between said first and second plates when a substantial force is applied to the bean. A high friction element may be sandwiched between the first and second plates to increase the sliding friction generated on relative movement of the plates, thereby increasing the reaction force restaining such movement.

Abstract: Disclosed herein is a manually operated control valve wherein a pressure regulating valve and exhaust valve are contained in the same housing with intercommunicating passages, both valves having actuating plungers which are operated by a single manual operating means, such as a lever. The invention includes apparatus for testing vehicle pneumatic braking systems wherein the manually operated control valve is used in conjunction with a pressure gauge to test the system by controlling the supply and exhaust of air to and from the vehicle braking system and observing accompanying variations in pressure.

Abstract: An anti-skid control system for use with vehicle brakes which system comprises a control device which actuates a valve to interrupt the passage of brake pressure to a brake chamber in a cyclic manner should the wheel associated with the brake chamber tend to lock or skid. A pump generates a control signal according to the rotational speed of the wheel and the device compares this signal with a signal derived from the brake pressure. The control device operates in conjunction with a number of further valve devices to initiate the aformentioned cyclic interruption of brake pressure to the brake chamber should the control signal fall below a pre-set threshold level and this control sequence repeats itself so the brakes are successively applied and released until the wheel ceases to skid so that the control signal again rises above the threshold level.