John E Waddington, 67Cranston, RI

4384665, May 24, 1983

May 4, 1981

6/260039

John E. Waddington - Warwick RI

Waddington Electric, Inc. - Cranston RI

B65H 2322
B65H 5900

226 42

A stock loop controller is disclosed which measures the round trip time of an ultrasonic signal transmitted to the stock loop and its return echo to generate a digital signal proportional to such time. The digital signal is converted to an analog signal and compared with a voltage reference across an amplifier. The resultant difference signal is used to control a motor operating the stock loop "take-up" or "feed-out" mechanism.

5150022, Sep 22, 1992

Mar 5, 1991

7/664655

John E. Waddington - Richmond RI

Waddington Electronics, Inc. - Cranston RI

G05B 902

318563

A pilot release for a press feeder has a spring-loaded support for one of two pinch rollers through which stock material is fed. A cam follower attached to the support engages a cam which is driven by a servo motor. During operation of the press, a position sensor on the press outputs a signal indicative of the position of the press crankshaft. The signal is input to a signal processor which includes a motor control circuit which drives the servo motor of the press feeder. A position sensor on the servo motor also inputs a signal to the signal processor which compares the position of the press to the position of the servo motor, and drives the servo motor to synchronize the motor to the press. The synchronization is such that as pilot pins of the press contact the stock material in the press, an eccentricity of the cam engages the cam follower. The spring-loaded support is thereby pivoted against the tendency of the spring, and the pinch rollers are momentarily separated, removing tension from the stock material and allow alignment by the pilot pins.