Michael B Grace

US Patent:

39596087, May 25, 1976

Filed:

Dec 10, 1974

Appl. No.:

5/531291

Inventors:

Thomas J. Finlayson - Palos Hills IL
Michael H. Grace - Griffith IN
George H. Smith - Hazelcrest IL

Assignee:

Allis-Chalmers Corporation - Milwaukee WI

International Classification:

H02G 1100

US Classification:

191 122R

Abstract:

The operator's station of a lift truck is optionally elevatable with the carriage and the electric control interconnection between the operator's station, and the truck main frame includes a novel reel mechanism for the multiple lead electric conduit which does not use slip rings. The reel mechanism includes two drums which rotate together on a stationary shaft secured to the main frame. One drum is for coiling a flexible multi-lead round conduit which has its free end connected to the electric control console at the operator's station. The other drum contains a multiple lead flexible ribbon having its outer end connected to the inner end of the round conduit. The ribbon is coiled about the stationary shaft with its radially inner end passing through a hollowed portion of the stationary shaft and thence to a point of connection to a terminal block on the main frame. As the operator's station is raised with the carriage the round conduit is reeled out from the primary drum thereby rotating it against the bias of a windup spring. As the round conduit is reeled out from the primary drum the secondary drum is coiling the loosely wound ribbon about the shaft thus increasing the number of turns of its coil.

US Patent:

39939421, Nov 23, 1976

Filed:

Sep 11, 1975

Appl. No.:

5/612537

Inventors:

Harvey E. Schmidt - Chicago Heights IL
Michael H. Grace - Griffith IN
Howard G. Murphy - Greendale WI

Assignee:

Allis-Chalmers Corporation - Milwaukee WI

International Classification:

H02P 706

US Classification:

318317

Abstract:

A forced commutation chopper control for regulating speed of a DC series tractive motor limits peak motor current by sensing the voltage across the commutation capacitor during the on-time of the current pulses and gating the commutation SCR on in response to a predetermined magnitude of sensed voltage to thereby terminate current pulses to the motor.