Abstract: A brake control mechanism is adapted to operate trailer brakes in an overrun manner, and to incorporate a handbrake mechanism. A draw shaft of a towing coupling acts on a first arm of an overrun brake link, which has a second arm on which there is provided a connection point for a brake rod. When the brakes are actuated in an overrun manner, the brake link is activated by the draw shaft and pivots about a first pivot point. When the handbrake mechanism is activated, the overrun brake link is caused to pivot about a second pivot point, such that the maximum travel of the aforementioned connection point for the brake rod is greater than in an overrun braking action. The overrun brake link is resiliently biased into a brake actuating position.

Abstract: The invention relates to towing couplings of a type comprising a fixed part and a moveable keeper which are together adapted to clamp on a tow-ball when the keeper is in a locking position but which are adapted to release the tow-ball when the keeper is moved to an unlocking position. A towing coupling according to the invention has a cam engaged with the keeper, a single spring urging the keeper away from its locking position into engagement with the cam, the spring also urging the cam in the direction of motion which causes it to apply a force to the keeper urging the keeper towards the locking position, and a lever connected to the cam for moving the latter against the action of the spring to allow the keeper to move away from the locking position.