Robert Paul Locke

US Patent:

39931803, Nov 23, 1976

Filed:

Aug 7, 1975

Appl. No.:

5/602728

Inventors:

Robert A. Locke - Lansdale PA

Assignee:

Sperry Rand Corporation - New York NY

International Classification:

B41J 132

US Classification:

197 49

Abstract:

A tabulation drive mechanism is described for use with an asynchronous printer mechanism of the sort including a rotating type wheel which has its characters arranged thereon along a helical path. The wheel is rotated continuously about the axis of the helical path during printing and a print drive mechanism includes a lead screw which is coupled to the wheel. A rack and pawl mechanism selectively holds the print wheel at columnar printing positions. The tabulation drive mechanism is basically independent of, and in addition to, the lead screw for driving the print wheel to the right or left during tabulation. The tabulation drive mechanism includes two oppositely acting motors which are linked to the print wheel via magnetic particle clutches. A logic circuit activating the magnetic clutches coordinates the print and tabulation drive mechanisms.