Bennie Of Chappell

US Patent:

44279329, Jan 24, 1984

Filed:

Mar 22, 1982

Appl. No.:

6/360218

Inventors:

Bennie Chappell - Menlo Park CA

International Classification:

H02P 706

US Classification:

318574

Abstract:

A drafting machine which employs two variable speed and one constant speed motors. A pencil is moved along both X- and Y-axes by means responsive to the speed differentials of the motors. Speeds of the motors are controlled by an electrical circuit having a plurality of off-on switches and a plurality of rocking switches. The latter load counters from a pulse generator into counters for straight line, circle, spiral and logarithmic spiral controls which control activation of resistors which govern the speeds of the two variable speed motors. Indicators indicate to the operator the direction in which the pencil is moving, the diameter of a circle being drawn, the increment (or decrement) of a spiral being drawn as compared with a circle and the increment (or decrement) of a logarithmic spiral being drawn as compared with a spiral.