Patent US4553040A successfully refreshed from Google Patents.
US4553040A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inductive proximity switch
Assignee: Individual
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Filing: 1983-07-06
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Granted: 1985-11-12
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Expires: 2003-07-06
Abstract
Abstract The invention relates to an inductive proximity switch having a feeler head with a feeler coil as a component of an LC oscillator circuit of a high frequency oscillator, the feeler head serving to generate a directionally oriented, alternating magnetic field, whereby the feeler coil of the feeler head is coupled with a closed circuit loop comprising an inductance and an ohmic resistance such that the oscillator is damped when the field is undisturbed and its damping is reduced when the field is disturbed by a nonmagnetic object such that an oscillation occurs.
Inventors
- 👤 Dirk Truper
- 👤 Klaus Hermle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:29
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/94; H03K17/945; H03K17/95; H03K17/952; H03K17/9537; H03K17/9542; H03K17/9547
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
132 words
Inductive proximity switch comprising a feeler head with a feeler coil as a component of an LC oscillator circuit of a high frequency oscillator with said feeler coil being disposed in the interior of a cup core being open at one end thereof, said feeler head serving to generate a directionally oriented, alternating magnetic field, wherein the feeler coil of the feeler head is coupled with a closed circuit loop being disposed at the open end of the cup core and adjacent to its outer wall, said closed circuit loop comprising an inductance and an ohmic resistance such that the oscillator is damped when the field is undisturbed and such that damping of the oscillator is reduced when the field is disturbed by a non-magnetic metal object such that an oscillation occurs.
Claim 2
Dependent Claim
132 words
Inductive proximity switch comprising a feeler head with a feeler coil as a component of an LC oscillator circuit of a high frequency oscillator with said feeler coil being disposed in the interior of a cup core being open at one end thereof, said feeler head serving to generate a directionally oriented, alternating magnetic field, wherein the feeler coil of the feeler head is coupled with a closed circuit loop being disposed at the open end of the cup core and adjacent to its outer wall, said closed circuit loop comprising an inductance and an ohmic resistance such that the oscillator is damped when the field is undisturbed and such that damping of the oscillator is reduced when the field is disturbed by a non-magnetic metal object such that an oscillation occurs.
Claim 3
Dependent Claim
31 words
The proximity switch of claim 1, wherein the ohmic resistance is selected such that the coupling present when the field is undisturbed results in a power matching which damps the oscillator.
Claim 4
Dependent Claim
17 words
The proximity switch of claim 1, wherein the closed circuit loop is formed by a metal ring.
Claim 5
Dependent Claim
15 words
The proximity switch of claim 3, wherein the metal ring consists of a magnetized material.
Claim 6
Dependent Claim
15 words
The proximity switch of claim 3, wherein the metal ring consists of a metal foil.
Claim 7
Dependent Claim
17 words
The proximity switch of claim 1, wherein the closed circuit loop comprises a resistor and an inductor.
Claim 8
Dependent Claim
17 words
The proximity switch of claim 6, wherein the inductance of the closed circuit loop is a coil.
Claim 9
Dependent Claim
39 words
The proximity switch of claim 7, wherein said closed circuit loop comprises a normally closed switch which can be selectively opened by control means in order to detect, instead of non-magnetic metal objects, objects made of a magnetizable material.
Claim 10
Dependent Claim
39 words
The proximity switch of claim 8, wherein said switch is periodically openable by the control means and wherein separate outputs are provided for evaluation of the output signals obtained from the closed circuit loop and an open circuit loop.
Claim 11
Dependent Claim
21 words
The proximity switch of claim 1, wherein evaluating means are provided for evaluating the voltage induced in the closed circuit loop.
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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) | 1988-11-11 | 1989-05-13 | 1989-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-11 | 1993-05-13 | 1993-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-11 | 1997-05-13 | 1997-11-12 | $7700.00 | Window Closed / Lapsed |