Patented Dec. 28, 1971 3,631,443

(1)

> *

XR 3 : 63.1 s 443

[11] 3,631,443

[72]

[21]

[22]

[45]

[73]

[54]

[52]

[51]

[50]

Inventors Martin O. Halfhill;

Timothy W. Martin, both of San Jose, Calif.

Appl. No. 842,942 Filed July 18, 1969 Patented Dec. 28, 1971

Assignee Information Storage Systems, Inc.

Cupertino, Calif.

UNSAFE VELOCITY DETECTION SYSTEM 4 Claims, 11 Drawing Figs.

U.S. Cl... 340/263, 340/282

Int. Cl... ... G08b5/22

Field of Search... 340/263, 268,271, 282

[56] References Cited

UNITED STATES PATENTS

2,913,662 11/1959 Hogan... 340/271 UX 3,146,432 8/1964 Johnson ... 340/.263 3,465,326 9/1969 Weir et al... 340/263 Primary Examiner—John W. Caldwell

Assistant Examiner—Michael Slobasky Attorney–Robert B. Crouch

ABSTRACT: An unsafe velocity detection system for use with a servo-controlled actuator connected to a movable load, in cluding a transducer for generating a signal indicating traverse by the load of a predetermined increment of the effective working area of the load, circuitry for developing a time-based signal from the traverse signal and means for comparing the traverse signal with the time-based signal to detect any exces sive velocity condition.

Patented Dec. 28, 1971 3,631,443

XR 3 : 63.1 s 443

[11] 3,631,443

THRESHOLD DETECTOR