US5726567A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Network-connectable displacement sensor with stored ID
Assignee: Weston Aerospace Ltd
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Filing: 1995-04-03
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Granted: 1998-03-10
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Expires: 2015-04-03
Abstract
Abstract A displacement sensor comprises a measuring head which measures displacement by variation in frequency of an oscillator due to movement of a core in a coil. The signal from the oscillator is used to gate a high frequency crystal clock into a counter. The count is representative of the change in frequency of the oscillator and thus the displacement to be measured. The count is compared by a microprocessor with a look-up table stored in the memory during initial calibration. The operating and processing electronics connected to the sensor head are mounted in a connector which can be directly coupled to connectors of other sensors to form a bus connecting multiple sensors to a data logger or computer.
Inventors
- 👤 Adrian Vivian Lewis
- 👤 Stephen Tony Kuc
- 👤 Douglas Dennis Weller
- 👤 Robert Stuart Burridge
- 👤 Kevin Anthony Snoad
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:11
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/16; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/20; G01D5/22; G01D5/2208; G01D5/2216; G01B7/02; G01D3/00; G01D3/02; G01D3/022; G01B2210/00; G01B2210/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
112 words
Apparatus for measuring displacement comprising a sensor head for varying the frequency of an oscillator in response to the displacement to be measured, means for measuring the frequency change, and a microprocessor for converting the measured frequency change to a digital output representing the displacement by reference to stored calibration coefficients specific to the sensor head, wherein the frequency measuring means and microprocessor are mounted in a connector remote from the sensor head, said connector being adapted to enable the connector to be plugged directly into similar connectors of other sensor heads, and the microprocessor contains a unique ID for that sensor head, allowing a host computer to identify each sensor head.
Claim 2
Dependent Claim
112 words
Apparatus for measuring displacement comprising a sensor head for varying the frequency of an oscillator in response to the displacement to be measured, means for measuring the frequency change, and a microprocessor for converting the measured frequency change to a digital output representing the displacement by reference to stored calibration coefficients specific to the sensor head, wherein the frequency measuring means and microprocessor are mounted in a connector remote from the sensor head, said connector being adapted to enable the connector to be plugged directly into similar connectors of other sensor heads, and the microprocessor contains a unique ID for that sensor head, allowing a host computer to identify each sensor head.
Claim 3
Dependent Claim
22 words
Apparatus as claimed in claim 1, in which the core is displaceable within a coil of the oscillator to vary the frequency.
Claim 4
Dependent Claim
36 words
Apparatus as claimed in claim 2, in which the core is displaceable between two coils which are alternately connected to the oscillator and the frequency change between the two coils provides a measure of the displacement.
Claim 5
Dependent Claim
41 words
Apparatus as claimed in claim 3, comprising a first counter coupled to the output of the oscillator and arranged to switch the connection between the coils and the oscillator after a time interval comprising at least n cycles of the oscillator.
Claim 6
Dependent Claim
49 words
Apparatus as claimed in claim 4, in which the means for measuring the frequency change comprises a second counter gated by the output of the first counter to count clock pulses, and means for generating a difference count corresponding to the difference of oscillator frequency betwen the two coils.
Claim 7
Dependent Claim
51 words
Apparatus as claimed in claim 4, in which the means for measuring the frequency change comprises a counter arranged to supply counts to the microprocessor corresponding to the two frequencies of the oscillator, the microprocessor being designed to calculate the difference in the frequencies for comparison with the stored calibration coefficients.
Claim 8
Dependent Claim
51 words
Apparatus as claimed in claim 4, in which the means for measuring the frequency change comprises a counter arranged to supply counts to the microprocessor corresponding to the two frequencies of the oscillator, the microprocessor being designed to calculate the ratio of the frequencies for comparison with the stored calibration coefficients.
Claim 9
Dependent Claim
18 words
Apparatus as claimed in claim 4, wherein the first counter and the oscillator are mounted in said connector.
References Cited (Backward Citations)
US3181961A
Cited
US3790910A
Cited
US4041470A
Cited
GB2060897A
Cited
US4349746A
Cited
US4335442A
Cited
GB2097536A
Cited
US4401351A
Cited
EP0079086A1
Cited
GB2115930A
Cited
WO1988000364A1
Cited
US4831558A
Cited
US4930096A
Cited
GB2207512A
Cited
GB2207511A
Cited
US4914610A
Cited
GB2207765A
Cited
US5006797A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-03-09 | 2001-09-08 | 2002-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-03-09 | 2005-09-08 | 2006-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-03-09 | 2009-09-08 | 2010-03-10 | $7700.00 | Window Closed / Lapsed |