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US3883796A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Proximity probe with output proportional to target distance
Assignee: Acme Cleveland Corp
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Filing: 1972-09-05
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Granted: 1975-05-13
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Expires: 1992-09-05
Abstract
Abstract A proximity probe circuit is disclosed which is responsive to the distance between a proximity probe and a conductive or an inductive target, and has an output directly proportional to the distance between the probe and a conductive target. An amplifier is connected as an oscillator in a bridge circuit with the probe in one arm of the bridge and variations of probe to target distance change the input to the amplifier. An output circuit is connected to the output of the amplifier and has a variable negative feedback to decrease the input to the amplifier as the output of the amplifier increases. This is accomplished by light emitting diodes and light sensitive resistors in one embodiment of the invention and the output circuit provides a means for determining an output voltage proportional to the probe to target distance.
Inventors
- 👤 Frederick R Holt
- 👤 Noah Flueckiger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:26
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/12; B; B07; B07C; B07C5/00; B07C5/04; B07C5/08; B07C5/086; G01B7/02; G01B7/023
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
128 words
A proximity probe circuit, comprising in combination, an amplifier having an output and an input, feedback means connecting said amplifier output to said amplifier input, a proximity probe, means connecting said probe as part of said feedback means to produce a signal at said input of said amplifier which is gradually variable in accordance with the change of distance from said probe to a conductive target, a bridge circuit having arms as part of said feedback means, variable means in said feedback means and included in two of said arms of said bridge circuit, and output means connected to said amplifier and including means controlling said variable means in accordance with said amplifier output to decrease the input signal to said amplifier upon an increase of amplifier output.
Claim 2
Dependent Claim
128 words
A proximity probe circuit, comprising in combination, an amplifier having an output and an input, feedback means connecting said amplifier output to said amplifier input, a proximity probe, means connecting said probe as part of said feedback means to produce a signal at said input of said amplifier which is gradually variable in accordance with the change of distance from said probe to a conductive target, a bridge circuit having arms as part of said feedback means, variable means in said feedback means and included in two of said arms of said bridge circuit, and output means connected to said amplifier and including means controlling said variable means in accordance with said amplifier output to decrease the input signal to said amplifier upon an increase of amplifier output.
Claim 3
Dependent Claim
29 words
A proximity probe circuit as set forth in claim 1, wherein said output means establishes an output directly proportional to the distance between said probe and a conductive target.
Claim 4
Dependent Claim
18 words
A proximity probe circuit as set forth in claim 1 wherein said variable means is a passive means.
Claim 5
Dependent Claim
31 words
A proximity probe circuit as set forth in claim 1, wherein said feedback means includes negative and positive feedback means, and said variable means is included in said negative feedback means.
Claim 6
Dependent Claim
18 words
A proximity probe circuit as set forth in claim 1, wherein said variable means includes variable impedance means.
Claim 7
Dependent Claim
20 words
A proximity probe circuit as set forth in claim 1, wherein said variable means is a light sensitive variable means.
Claim 8
Dependent Claim
34 words
A proximity probe circuit as set forth in claim 6, including light-emitting means optically coupled to said light sensitive means, and said output means including means connecting said light-emitting means to said amplifier output.
Claim 9
Dependent Claim
26 words
A proximity probe circuit as set forth in claim 7, wherein said output means connecting said light-emitting means to said amplifier output includes differential amplifier means.
Claim 10
Dependent Claim
25 words
A proximity probe circuit as set forth in claim 7, wherein said light sensitive means is a photoresistor and said light-emitting means is a photodiode.
Claim 11
Dependent Claim
57 words
A proximity probe circuit as set forth in claim 9, wherein said light-emitting means is connected to said amplifier output to effect an increase in light emission upon an increased amplifier output, and said light sensitive means is connected in said feedback means to increase negative feedback to said amplifier upon illumination by said increased light emission.
Claim 12
Dependent Claim
126 words
A proximity probe circuit, comprising, in combination, an amplifier having an output and an input, feedback means connecting said amplifier output to said amplifier input, a proximity probe, means connecting said probe as part of said feedback means to produce a signal at said input of said amplifier which is gradually variable in accordance with the change of distance from said probe to a conductive target. variable means in said feedback means, output means connected to said amplifier and including means controlling said variable means in accordance with said amplifier output to decrease the input signal to said amplifier upon an increase of amplifier output, said variable means including first and second light sensitive means, and means connecting said light sensitive means to act in push-pull.
Claim 13
Dependent Claim
126 words
A proximity probe circuit, comprising, in combination, an amplifier having an output and an input, feedback means connecting said amplifier output to said amplifier input, a proximity probe, means connecting said probe as part of said feedback means to produce a signal at said input of said amplifier which is gradually variable in accordance with the change of distance from said probe to a conductive target. variable means in said feedback means, output means connected to said amplifier and including means controlling said variable means in accordance with said amplifier output to decrease the input signal to said amplifier upon an increase of amplifier output, said variable means including first and second light sensitive means, and means connecting said light sensitive means to act in push-pull.
Claim 14
Dependent Claim
144 words
A proximity probe circuit, comprising, in combination, an amplifier having an output and an input, feedback means connecting said amplifier output to said amplifier input, a proximity probe, means connecting said probe as part of said feedback means to produce a signal at said input of said amplifier which is gradually variable in accordance with the change of distance from said probe to a conductive target, variable means in said feedback means, output means connecting to said amplifier and including means controlling said variable means in accordance with said amplifier output to decrease the input signal to said amplifier upon an increase of amplifier output, said amplifier having both an alternating and a direct current output, said feedback means including alternating current feedback means feeding back alternating current to said amplifier input, and said output means including means responsive to the direct current output.
Claim 15
Dependent Claim
144 words
A proximity probe circuit, comprising, in combination, an amplifier having an output and an input, feedback means connecting said amplifier output to said amplifier input, a proximity probe, means connecting said probe as part of said feedback means to produce a signal at said input of said amplifier which is gradually variable in accordance with the change of distance from said probe to a conductive target, variable means in said feedback means, output means connecting to said amplifier and including means controlling said variable means in accordance with said amplifier output to decrease the input signal to said amplifier upon an increase of amplifier output, said amplifier having both an alternating and a direct current output, said feedback means including alternating current feedback means feeding back alternating current to said amplifier input, and said output means including means responsive to the direct current output.
Claim 16
Dependent Claim
144 words
A proximity probe circuit, comprising, in combination, an amplifier having an output and an input, feedback means connecting said amplifier output to said amplifier input, a proximity probe, means connecting said probe as part of said feedback means to produce a signal at said input of said amplifier which is gradually variable in accordance with the change of distance from said probe to a conductive target, variable means in said feedback means, output means connected to said amplifier and including means controlling said variable means in accordance with said amplifier output to decrease the input signal to said amplifier upon an increase of amplifier output, means supplying a direct current input to said amplifier wherein said amplifier acts as an oscillator and has both an alternating and a direct current output, and said output means including means responsive only to the direct current output.
Claim 17
Dependent Claim
144 words
A proximity probe circuit, comprising, in combination, an amplifier having an output and an input, feedback means connecting said amplifier output to said amplifier input, a proximity probe, means connecting said probe as part of said feedback means to produce a signal at said input of said amplifier which is gradually variable in accordance with the change of distance from said probe to a conductive target, variable means in said feedback means, output means connected to said amplifier and including means controlling said variable means in accordance with said amplifier output to decrease the input signal to said amplifier upon an increase of amplifier output, means supplying a direct current input to said amplifier wherein said amplifier acts as an oscillator and has both an alternating and a direct current output, and said output means including means responsive only to the direct current output.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |