Counterbalance actuator having an extended stroke

摘要

A counterbalance actuator is disclosed for reducing the energy required in weight lifting operations. The counterbalance actuator includes a piston and a flexible bellows attached to the piston. A bellows extension is attached to the top of the bellows with a gas impervious seal. The bellows extension permits the counterbalance actuator to achieve an extended stroke while allowing the counterbalance actuator to be collapsed to a reduced size.