Method of measuring long shaft torque

Claim 1

A method of measuring long shaft torque comprising the steps of: (a) pre-recording a pair of magnetic tapes with similar sine wave signals in the audio frequency range and without shaft skew errors, said tapes having lengths for looping around said long shaft with respective ends meeting and the sine wave signal of each loop being continuous and said pre-recording comprising the steps of: mounting said magnetic tapes on a recording wheel having a larger circumference than said long shaft; rotating said recording wheel on a short shaft mounted to turn without skew; and gating an audio generator and amplifier to simultaneously record a sine wave signal on both said tapes for one turn only of said recording wheel; (b) fixing said pre-recorded magnetic tapes in loops and mounting said tapes spaced longitudinally around said long shaft with the sine wave signals of the loops in phase; (c) rotating said long shaft under a torque load; (d) picking up phase shifts in the sine wave signals at two diametrically opposed sides of the longitudinally spaced, pre-recorded tape loops with two pairs of magnetic playback heads; (e) electronically generating analog voltages from said phase shifted sine wave signals and long shaft skew at each side of said rotating long shaft and tape loops that are respectively proportional to half said torque load plus and minus long shaft skew errors; and (f) electronically adding said half torque analog voltages to obtain their sum less the plus and minus skew errors which cancel in the summing to give an analog voltage proportional to the full torque load for reading directly from a voltmeter calibrated in torque.

Claim 2

A method of measuring long shaft torque comprising the steps of: (a) pre-recording a pair of magnetic tapes with similar sine wave signals in the audio frequency range and without shaft skew errors, said tapes having lengths for looping around said long shaft with respective ends meeting and the sine wave signal of each loop being continuous and said pre-recording comprising the steps of: mounting said magnetic tapes on a recording wheel having a larger circumference than said long shaft; rotating said recording wheel on a short shaft mounted to turn without skew; and gating an audio generator and amplifier to simultaneously record a sine wave signal on both said tapes for one turn only of said recording wheel; (b) fixing said pre-recorded magnetic tapes in loops and mounting said tapes spaced longitudinally around said long shaft with the sine wave signals of the loops in phase; (c) rotating said long shaft under a torque load; (d) picking up phase shifts in the sine wave signals at two diametrically opposed sides of the longitudinally spaced, pre-recorded tape loops with two pairs of magnetic playback heads; (e) electronically generating analog voltages from said phase shifted sine wave signals and long shaft skew at each side of said rotating long shaft and tape loops that are respectively proportional to half said torque load plus and minus long shaft skew errors; and (f) electronically adding said half torque analog voltages to obtain their sum less the plus and minus skew errors which cancel in the summing to give an analog voltage proportional to the full torque load for reading directly from a voltmeter calibrated in torque.

Claim 4

A method of pre-recording a pair of magnetic tapes with similar sine wave signals in the audio frequency range, said tapes having signals for looping around a long shaft with respective ends meeting and the sine wave signal of each loop being continuous, comprising the steps of: (a) mounting said magnetic tapes on a recording wheel having a larger circumference than said long shaft; (b) rotating said recording wheel on a short shaft mounted to turn without skew; (c) producing an audio signal and recording said signal simultaneously on both tapes for one turn only of said recording wheel; and (d) mounting said pre-recorded magnetic tapes in loops spaced longitudinally of said long shaft with signals recorded on said tapes in phase.

Claim 5

A method of pre-recording a pair of magnetic tapes with similar sine wave signals in the audio frequency range, said tapes having signals for looping around a long shaft with respective ends meeting and the sine wave signal of each loop being continuous, comprising the steps of: (a) mounting said magnetic tapes on a recording wheel having a larger circumference than said long shaft; (b) rotating said recording wheel on a short shaft mounted to turn without skew; (c) producing an audio signal and recording said signal simultaneously on both tapes for one turn only of said recording wheel; and (d) mounting said pre-recorded magnetic tapes in loops spaced longitudinally of said long shaft with signals recorded on said tapes in phase.

Claim 7

A method of measuring long shaft torque comprising the steps of: (a) affixing sine wave signals at longitudinally spaced locations about the periphery of said long shaft with the sine wave signals in phase; (b) rotating said long shaft under a torque load; (c) picking up phase shift signals in the sine wave signals at two diametrically opposed sides of the longitudinally spaced signals with two pairs of magnetic playback heads; (d) independently integrating each of said phase shifts; (e) electronically adding said integrated phase shifts.

Claim 8

A method of measuring long shaft torque comprising the steps of: (a) affixing sine wave signals at longitudinally spaced locations about the periphery of said long shaft with the sine wave signals in phase; (b) rotating said long shaft under a torque load; (c) picking up phase shift signals in the sine wave signals at two diametrically opposed sides of the longitudinally spaced signals with two pairs of magnetic playback heads; (d) independently integrating each of said phase shifts; (e) electronically adding said integrated phase shifts.