Donnie L Martin

US Patent:

48077240, Feb 28, 1989

Filed:

Mar 31, 1988

Appl. No.:

7/176062

Inventors:

Donnie L. Martin - Mercersburg PA

Assignee:

D. L. Martin Company - Mercersburg PA

International Classification:

B66B 904

US Classification:

187110

Abstract:

In an energy efficient hydraulic elevator driving system, a substantially constant amount of pressurized fluid is displaceable within a closed system between two hydraulic jacks with a piston-cylinder combination interconnected by a piping system. The translational movement of a shaft engaging the piston in the first cylinder is transmitted through fluid to the second cylinder to effect movement of the hydraulic jack for lowering and raising the elevator car. A counter-weight is provided at the opposite end of the shaft which constantly compresses the pressurized fluid in the first cylinder and balances the weight of the elevator car which is supported by a hydraulic jack plunger. Therefore only a relatively small amount of additional energy is necessary to lower and raise the elevator car.