John P Gilliland

US Patent:

46497269, Mar 17, 1987

Filed:

Sep 9, 1985

Appl. No.:

6/774283

Inventors:

William M. Trammell - Claremore OK
Criswell G. Hutchens - Tulsa OK
John R. Gilliland - Tulsa OK
Stanton R. Hill - Tulsa OK

International Classification:

B21C 124
B21C 5100

US Classification:

72 34

Abstract:

A system for determining the bend in a section of a pipe which comprises supporting the pipe section on a conventional pipe bending apparatus which consists essentially of a device for holding the pipe section in a relatively horizontal position, for maintaining a first end of the pipe section in a relatively fixed position and for exerting a transverse force against a second and opposite end of the pipe section for creating a bend in the pipe section between the two ends thereof; mounting a first transducer on the first end of the pipe section, the first transducer providing a variable voltage depending upon the angle of the first end of the pipe section relative to the horizontal, mounting a second transducer on the second end of the pipe section, the second transducer providing a variable voltage depending upon the angle of the second end of the pipe section relative to the horizontal, exerting a bending force at the second end of the pipe section to create a bend in the pipe section between the two ends thereof, converting the voltage produced by the first transducer into a first radio frequency signal whose frequency varies with the strength of the voltage produced by the first transducer, converting the voltage produced by the second transducer into a second radio frequency signal whose frequency varies with the strength of the voltage produced by the second transducer, receiving the first and second radio frequency signals in a receiver capable of determining the difference in frequency between the two signals, differentiating the two radio frequency signals in the receiver, and providing a readout based upon this differentiation in terms of the angular difference between the two ends of the pipe section.