Patent ID: 8851237
Filing Date: 2014-10-07
Classification: B66F

Abstract:
1. A load elevator comprising: a base; a load platform mechanically coupled to the base and moveable between an extended position and a retracted position with respect to the base; a pneumatic actuator adapted to support the platform between said retracted and extended positions, said pneumatic actuator being pressurized at an actuator pressure; and a pneumatic system with a plurality of reservoirs connected to the pneumatic actuator through a direct pneumatic connection; wherein said reservoirs include respective valves for alternative uninterrupted pneumatic connection to the pneumatic actuator during operation with correspondingly alternative fixed volume capacities of the pneumatic system for different closed-pneumatic-system modes of operation of the load elevator, each of said reservoirs being pneumatically pressurized to said actuator pressure when pneumatically connected to the pneumatic actuator and during each of said different modes of operation of the load elevator.