Patent ID: 7721850

Claim:
A height adjustment mechanism for a lift device, the lift device including a base, a movable lift car, and a lifting mechanism that selectively elevates the lift car relative to the base from a lowered position to an elevated position, the height adjustment mechanism serving to adjust the maximum height to which the lift car can be elevated, the height adjustment mechanism comprising in combination: a) a rail that extends between first and second opposing ends, the rail being secured to the lift car, and the rail being elevated and lowered in accordance with raising and lowering of the lift car; b) an actuator supported for movement along the rail generally between the first and second ends thereof, the actuator being disposed generally proximate to the first end of the rail when the lift car is in its lowered position, the actuator being biased away from the second end of the rail; c) an elongated flexible cable having first and second ends, the first end of such cable being coupled to the actuator, and the second end of the cable being coupled to an anchor point, the cable urging the actuator toward the second end of the rail as the lift car is elevated; and d) a first proximity sensor adjustably mounted to the rail, the first proximity sensor detecting that the actuator is proximate thereto, and generating an electrical signal indicative thereof; e) the lifting mechanism of the lift device being responsive to the electrical signal generated by the first proximity sensor for halting any further elevation of the lift car when the actuator is proximate to the first proximity sensor.