Patent ID: 7429061
Filing Date: 2008-09-30
Classification: B60S

Abstract:
1. A trailer lift assembly comprising: a frame; first and second legs each including an upper part connected to the frame and a lower part movable with respect to the upper part to shorten and lengthen the legs; a motor rigidly mounted to the frame and including a rotatable motor shaft; a gearbox rigidly mounted to the frame and having first and second gear arrangements, a rotatable input shaft having a longitudinal axis and being supported for translational axial movement between a first position in which the input shaft engages and rotates the first gear arrangement and a second position in which the input shaft engages and rotates the second gear arrangement, and a rotatable output shaft rotating at first and second different speed ratios with respect to the speed of rotation of the input shaft in response to the input shaft rotating the respective first and second gear arrangements; and a coupling mechanism including inner and outer couplers coupled for rotation together, the inner coupler being received within the outer coupler to permit telescopic movement of the inner and outer couplers with respect to each other, one of the inner and outer couplers being mounted for rotation with the motor shaft and the other being mounted for rotation with the input shaft, one of the inner and outer couplers including at least one slot and the other of the inner and outer couplers including at least one bearing received in and slidable along the at least one slot to accommodate movement of the input shaft between the first and second positions and to transfer torque from the motor shaft to the input shaft to cause rotation of the input shaft in response to rotation of the motor shaft; wherein the output shaft is operably interconnected with both the first and second legs to cause the lower parts of the legs to move with respect to the upper parts at a first rate in response to the input shaft rotating the first gear arrangement, and at a second rate in response to the input shaft rotating the second gear arrangement.