Patent ID: 11859423
Assignee: nan
Field: Transport (Mechanical engineering)
Classification: CPC E  B | IPC B  E

Claim 0:
1. A counterbalance mechanism for a lift door system, comprising:
an adjustable length torque shaft positionable above a lift door, wherein length of the torque shaft is selected to extend at least proximate to a width of the lift door;
two cable drums mounted proximate to opposite ends of the adjustable length torque shaft for rotation with the torque shaft, the cable drums supporting flexible cables that connect to the lift door to support at least a portion of weight of the lift door; and
two torsion springs disposed around the adjustable length shaft and operably connected to the adjustable length torque shaft, wherein the two torsion springs exert a torsional force on the adjustable length torque shaft to counterbalance at least a portion of the weight of the lift door and assist in movement of the lift door, where each of the torsion springs are anchored to a mounting bracket; and
wherein the adjustable length torque shaft comprises a plurality of shaft lengths, wherein the shaft lengths are assembled end to end to form the adjustable length torque shaft.