Landing legs for trailers.

摘要

A landing leg operating system for a trailer landing leg (10) having an upper part (12) fixed to the trailer and a lower part (14) which is displaced vertically to increase or decrease the length of the leg (10) includes a reversible air motor (62). Air is caused to flow through the motor (62) one way to raise the leg (10) and the other way to lower the leg (10). Quick release valves (68,70) are connected to the motor (62) on opposite sides thereof. Air can flow through either valve (68,70) to the motor (62) but air reaching either valve (68,70) from the motor (62) is dumped to atmosphere. Air for raising the leg (10) is taken from the trailer's emergency brake line (120) as the trailer is coupled to a tractor. Air for lowering the leg (10) is taken either manually or automatically from the emergency air brake reservoir (124) to which said emergency brake line (120) is connected as the trailer is uncoupled from the tractor. <IMAGE>