US3800423A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for measuring pitch or indexing errors in toothed members
Assignee: Goulder J and Sons Ltd
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Filing: 1972-10-26
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Granted: 1974-04-02
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Expires: 1992-10-26
Abstract
Abstract The described apparatus for measuring pitch errors in a gear wheel consists of a motor-driven continuously-rotable support for the gear wheel, to which support is coupled a circular grating type pulse generator whose electrical pulse output is electronically processed by a multiplier and a divider to produce a reference pulse train whose count is directly proportional to the tooth pitch of the gear wheel. These pulses are then shaped to produce a train of clearly defined reference signals. A reciprocatory probe carrier is provided for inserting a probe successively into the spaces between adjacent gear teeth synchromously with rotation of the gear. A sample-and-hold amplifier passes a probe deflection signal to a recorder on each occurrence of a reference signal. A trigger device connected to the probe output is used during the initial probe deflection to make the first reference pulse coincide with the arbitary value of probe deflection signal selected conveniently on approximately 50 percent of the maximum value of probe deflection signal. Thereafter, the probe deflection signals are measured on the occurence of each subsequent reference signal and deviation from the selected value is recorded.
Inventors
- 👤 R Munro
- 👤 R Hale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:04
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/28; G01B11/00; G01B11/24; G01B3/00; G01B3/02; G01B5/00; G01B5/14; G01B5/16
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
318 words
Apparatus for measuring errors in the tooth pitch of a gear wheel, comprising a continuously rotatable support whereon a gear wheel may be mounted co-axially with the support for rotation therewith, a pulse generator connected to the rotatable support and adapted to produce a train of source pulses whose count is proportional to angular displacement of the rotatable support, digital processing means connected to the pulse generator and adapted to convert the source pulse train to a train of reference signals which are mutually spaced according to the specified tooth pitch of a gear wheel and including means operable to synchronise the reference signals with an external event, a measuring probe having a stylus which can be influenced so as to produce a tooth position signal of amplitude proportional to the amount by which the stylus is influenced, means co-operatevely associated with the support and with the measuring probe and adapted to insert from a fixed station adjacent the periphery of the rotatable support the stylus a selected radial distance into successive tooth spaces of a gear wheel when mounted on and rotated continuously by the rotatable support and to withdraw the stylus from each tooth space after the stylus has been influenced by a tooth flank, a trigger device connected to the probe and to the synchronising means of the digital processing means and sensitive to a selected intermediate amplitude value of the tooth position signal and operative on a first single occurence of the said intermediate amplitude value to synchronise the train of reference signals with the event of said intermediate amplitude value, a sampling device connected to the probe and to the digital processing means and adapted to measure the instantaneous amplitude value of the tooth position signal on the occurrence of each reference signal, and means connected to the sampling device for indicating or recording the instantaneous amplitude values measured by the sampling device.
Claim 2
Dependent Claim
318 words
Apparatus for measuring errors in the tooth pitch of a gear wheel, comprising a continuously rotatable support whereon a gear wheel may be mounted co-axially with the support for rotation therewith, a pulse generator connected to the rotatable support and adapted to produce a train of source pulses whose count is proportional to angular displacement of the rotatable support, digital processing means connected to the pulse generator and adapted to convert the source pulse train to a train of reference signals which are mutually spaced according to the specified tooth pitch of a gear wheel and including means operable to synchronise the reference signals with an external event, a measuring probe having a stylus which can be influenced so as to produce a tooth position signal of amplitude proportional to the amount by which the stylus is influenced, means co-operatevely associated with the support and with the measuring probe and adapted to insert from a fixed station adjacent the periphery of the rotatable support the stylus a selected radial distance into successive tooth spaces of a gear wheel when mounted on and rotated continuously by the rotatable support and to withdraw the stylus from each tooth space after the stylus has been influenced by a tooth flank, a trigger device connected to the probe and to the synchronising means of the digital processing means and sensitive to a selected intermediate amplitude value of the tooth position signal and operative on a first single occurence of the said intermediate amplitude value to synchronise the train of reference signals with the event of said intermediate amplitude value, a sampling device connected to the probe and to the digital processing means and adapted to measure the instantaneous amplitude value of the tooth position signal on the occurrence of each reference signal, and means connected to the sampling device for indicating or recording the instantaneous amplitude values measured by the sampling device.
Claim 3
Dependent Claim
13 words
Apparatus according to claim 1, wherein the source pulses are electrical source pulses.
Claim 4
Dependent Claim
48 words
Apparatus according to claim 2, wherein the pulse generator comprises a light source, a photo-electRic transducer, a circular grating rotatable with the support, and one or more stationary indexing gratings co-operating with the circular grating to interrupt a light beam between the light source and the photo-electric transducer.
Claim 5
Dependent Claim
13 words
Apparatus according to claim 1, wherein the reference signals are electrical reference signals.
Claim 6
Dependent Claim
51 words
Apparatus according to claim 4, wherein the digital processing means comprises an electronic multiplier for multiplying the source pulse count by the number of teeth in a gear wheel, and an electronic divider for dividing the multiplier quotient by the source pulse count, the electronic divider incorporating the said synchronising means.
Claim 7
Dependent Claim
23 words
Apparatus according to claim 1, wherein the measuring probe comprises a mechanical-to-electrical transducer, said tooth position signal being an electrical tooth position signal.
Claim 8
Dependent Claim
36 words
Apparatus according to claim 1, wherein the said selected intermediate amplitude value is approximately equal to one-half of the maximum amplitude value of the stylus tooth position signal capable of being produced by the measuring probe.
Claim 9
Dependent Claim
25 words
Apparatus according to claim 1, including a pulse shaper associated with the digital processing means for improving the sharpness of definition of the reference signals.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |