US 5,490,758 A · Pit-mounted load elevator

Abstract

A self-adjusting pneumatic load elevator is adapted for mounting in a pit so that it can be used with pallet trucks. The elevator has a base, a rotatable, horizontal load platform, a vertically expandable scissors linkage mechanically coupled between the load platform and the base, and an air actuator chamber. To accommodate a rectangular pit opening, the load platform has a circular, rotatable portion surrounded by a rectangular, non-rotatable transition frame which fits with small clearance in the pit opening. An automatic brake prevents the rotation of the load platform when it is flush with the floor, and lightweight, vertically movable skirts on the load platform can strike a worker's toe to warn of danger. To prevent dangerous rebounds, when the elevator fully descends, it automatically releases the air in the air actuator chamber.

Claims21

Dependent claims

A self-adjusting load elevator for mounting in a pit in a floor, comprising:

a base, a rotatable load platform, and a vertically expandable scissors linkage mechanically coupled between the load platform and the base;
a fluid actuator chamber mechanically coupled to said scissors linkage and adapted to actuate the scissors linkage, said actuator chamber being expandable and contractible;
an isobaric fluid system fluidly coupled to said actuator chamber to provide a fluid to the actuator chamber when it expands and to receive back fluid therefrom when it contracts, said fluid system comprising a fluid reservoir and a fluid source coupled thereto;
a fluid inlet/outlet valve fluidly coupled to the fluid system to control a pressure thereof;
and
means for preventing a rotation of the load platform when it is approximately flush with the floor.

3 more elements

Dependencies are inferred from the claim text.

Pit-mounted load elevator

Life of this patent

Pit-mounted load elevator

Life of this patent

Abstract

Claims21