Patent US4006637A successfully refreshed from Google Patents.
US4006637A
Expired / Lapsed
US
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Electro-mechanical displacement transducer
Assignee: Individual
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Filing: 1976-05-07
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Granted: 1977-02-08
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Expires: 1996-05-07
Abstract
Abstract An electro-mechanical displacement transducer comprises a probe on which shunt capacitance and series inductance are uniformly distributed to form a distributive constant circuit. The probe includes a nonconductive central member coaxially covered by cylindrical inner and outer conductor members insulated and separated from each other, at least one such conductor member being a coil. A pulse source connects to the sending end of the probe and a circuit element having an impedance related to the characteristic impedance of the distributed constant circuit connects the inner and outer conductor members at the receiving end of the probe. In use, the probe is displaceable with respect to a wave reflecting means such that the duration, between the time when a pulse is applied to the sending end of the probe and the arrival of the reflected wave at the sending end of the probe, varies in direct proportion to the relative displacement of the probe and wave reflecting means.
Inventors
- 👤 Yohei Kinosita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:49
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/28; G01F23/284
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
176 words
An electro-mechanical displacement transducer comprising a probe on which shunt capacitance and series inductance are uniformly distributed lengthwise to form a distributive constant circuit, said probe including elongate substantially coaxial hollow conductor members with annular insulating means interposed therebetween, at least one of said conductor members being a tightly wound coil extending lengthwise of said probe, means having an impedance equivalent to the characteristic impedance of the distributive constant circuit and connecting said inner and outer conductor members at the receiving end of the probe, said conductor members having sending ends, remote from said receiving end, connectible to an electrical wave generating means, said probe including a hollow space extending longitudinally thereof for receiving relatively movable means introducing an impedance variation shiftable therein lengthwise of said probe, whereby the position of such impedance variation means movable inside said probe is detectable by the span of time during which an electromagnetic wave emitted from the sending end of the distributive constant circuit travels to and back from the location of said impedance variation means in said probe.
Claim 2
Dependent Claim
176 words
An electro-mechanical displacement transducer comprising a probe on which shunt capacitance and series inductance are uniformly distributed lengthwise to form a distributive constant circuit, said probe including elongate substantially coaxial hollow conductor members with annular insulating means interposed therebetween, at least one of said conductor members being a tightly wound coil extending lengthwise of said probe, means having an impedance equivalent to the characteristic impedance of the distributive constant circuit and connecting said inner and outer conductor members at the receiving end of the probe, said conductor members having sending ends, remote from said receiving end, connectible to an electrical wave generating means, said probe including a hollow space extending longitudinally thereof for receiving relatively movable means introducing an impedance variation shiftable therein lengthwise of said probe, whereby the position of such impedance variation means movable inside said probe is detectable by the span of time during which an electromagnetic wave emitted from the sending end of the distributive constant circuit travels to and back from the location of said impedance variation means in said probe.
Claim 3
Dependent Claim
133 words
An electro-mechanical displacement transducer as claimed in claim 1 in which said probe includes a nonconductive hollow pipe disposed within said conductor members, said one conductor member being a coil tightly wound around said nonconductive hollow pipe, the other conductor member being a cylindrical outer conductor insulatingly and coaxially disposed close to said coil, said coil and outer conductor being connected at the receiving ends by said impedance means, said impedance variation means comprising a ferromagnetic inner core slidably fitted in said hollow pipe, whereby the position of said inner core moving inside said hollow pipe is detected by said span of time during which said electromagnetic wave emitted from the sending end of the distributive constant circuit travels within said coil to and back from the position corresponding to said inner core.
Claim 4
Dependent Claim
139 words
An electro-mechanical displacement transducer as claimed in claim 1 in which said probe includes a nonconductive hollow pipe, said conductor members comprising an inner coil wound tightly on said hollow pipe and an outer coil tightly wound coaxially with and oppositely with respect to said inner coil and being insulated therefrom, said inner and outer coils being connected to each other at said receiving end through said impedance means, said impedance variation means comprising a ferromagnetic inner core slidably fitted in said hollow pipe, whereby the position of said inner core moving inside said hollow pipe is detected by means of the span of time during which an electromagnetic wave applied to the sending end of said distributive constant circuit travels within either the inner or the outer coil to and back from the position of said inner core.
Claim 5
Dependent Claim
84 words
An electro-mechanical displacement transducer as claimed in claim 1 in which said probe includes a nonconductive hollow pipe disposed inside said conductor members, said impedance variation means comprising a ferromagnetic inner core slidably fitted in said hollow pipe, and including a float connected to said inner core and arranged with respect to said pipe for keeping such inner core afloat above a liquid entering such hollow pipe, whereby said span of time provides an indication of liquid level along the length of such probe.
Claim 6
Dependent Claim
151 words
An electro-mechanical displacement transducer as claimed in claim 1 in which said probe comprises a nonconductive solid cylinder at the center thereof, the inner of said conductor members being a coil tightly wound on said nonconductive solid cylinder, the remaining said conductor member being a cylindrical outer conductor disposed coaxially around and radially spaced from said coil, said cylindrical outer conductor having a longitudinal slit for entry of a liquid therethrough into the space between said conductor members, said impedance means being connected to the receiving ends of said coil and outer conductor, whereby the distance between sending end of the distributed constant circuit and the surface of a liquid entering the outer conductor through its slit is detected by means of the span of time during which an electromagnetic wave applied to the sending end travels within the coil to and back from the position corresponding to the liquid surface.
Claim 7
Dependent Claim
77 words
An electro-mechanical displacement transducer as claimed in claim 1 including a constant voltage source and a circuit having an impedance equivalent to the characteristic impedance of the distributed constant circuit normally connecting said constant voltage source across the sending ends of said conductor members, said circuit including electronic valve means actuable to short circuit the sending ends of said conductor members so as to apply a voltage step constituting said electromagnetic wave to the distributive constant circuit.
Claim 8
Dependent Claim
167 words
An electro-mechanical displacement transducer as claimed in claim 6 including an instrumentation circuit for measuring the relative displacement of said probe and said impedance varying means, said instrumentation circuit including a source of clock pulses and a counter and an AND gate interconnecting same, electronic switch means actuable simultaneously with application of said voltage step to said probe sending end for turning on said AND gate and thereby causing said counter to accumulate clock pulses, current switch means responsive to reflection of said voltage step from the location along said probe of said impedance variation means for producing an output, flip-flop means controlling a further input of said AND gate in response to said current switch means output for turning off said AND gate, such that the number of pulses accumulated by said counter corresponds to the separation of said impedance variation means from said sending end of said probe and hence is a measure of relative displacement as between said impedance variation means and said probe.
Claim 9
Dependent Claim
72 words
An electro-mechanical displacement transducer as claimed in claim 7 in which said instrumentation circuit further includes reset switch means operable to reset said counter and set said flip-flop means for a further cycle of operation, and including manual switch means in series with a voltage source and operable for simultaneously applying said voltage step to said probe sending end and to enable said AND gate in cooperation with the set flip-flop means.
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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) | 1980-02-08 | 1980-08-09 | 1981-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-08 | 1984-08-09 | 1985-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-08 | 1988-08-09 | 1989-02-08 | $7700.00 | Window Closed / Lapsed |