Patent attributes
A self-tensioning tie down assembly (2) for tightening retaining straps (70) about winches (64) securing cargo (71) on a carrier (73). The assembly (2) has an actuator (15) connected to a pneumatic circuit (61) and providing reciprocating linear motion to a torque linkage (60) connected to the winch (64). The torque linkage (60) has a wrap spring clutch (17) connectable to the ratchet wheel (7) of the winch (64) and a connector arm (11) connected to the actuator (15). The torque linkage (60) transmits the linear motion to the winch (64) as a corresponding rotational motion. The required tension level of the retaining strap (70) is pre-set. Pressure within the circuit (61) drives the actuator (15) thereby actuating the torque linkage (60) which tightens the strap (70) on the winch (64) until the tension level is reached. The flow of pressure to the actuator (15) is controlled by a control valve (18) having a valve lever (19) that is toggled back and forth between an extend position and a retract position by a pair of opposed trip mounts (31, 32) mounted on the connector arm (11).
