US4994738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Proximity switch for detecting a magnetic inductive field
Assignee: Soyck GmbH
•
Filing: 1989-01-17
•
Granted: 1991-02-19
•
Expires: 2009-01-17
Abstract
Abstract An inductive proximity switch comprises a high-frequency oscillator, an oscillator coil and an oscillator core. An analyzing circuit detects the inclination amplitude depending on the degree of core saturation. The analyzing circuit triggers a switching process when a certain threshold value of amplitude is reached. The core consists, for example, of ferrite. A yoke-like body is assigned to the core. The use of such a soft-magnetic material for the yoke-like body, allows the construction of smaller sensors with a higher sensitivity and a more cost-advantageous production. Their permeability curve in relation with one quadrant of the coordinate system is clearaly S-shaped.
Inventors
- 👤 Gerno Soyck
- 👤 Peter Dahlheimer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:53
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/94; H03K17/945; H03K17/95; H03K17/952; H03K17/9537; H03K17/9542; H03K17/9547; G; G01; G01V; G01V3/00; G01V3/08; G01V3/10; G01V3/101; G01V3/102; H03K17/9505; F; F16; F16B; F16B15/00; F16B15/0023; F16B15/003; F16B15/0046; F16B15/0053; F16B2015/0069; F16B2015/0076
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
144 words
Inductive proximity switch comprising a high-frequency oscillator, wherein an oscillator coil is provided with an open core, saturation-sensitive to a magnetic field to be detected, in connection with an evaluation circuit, which detects the oscillation amplitude depending on the degree of the core saturation, and which, upon reaching of a certain amplitude value, triggers a switching process, wherein a foil-shaped anchor plate (4), made of a soft-magnetic metal alloy with a certain permeability, is coordinated to the open core (1) of the oscillator coil (2) under formation of an air gap (3), which anchor plate allows an oscillator current (I o ) to rise in a defined way upon intensification of the magnetic field from the damped state of said high frequency oscillator (10) or, respectively, upon a weakening of this field allows in a defined way to drop again in a damp state.
Claim 2
Dependent Claim
144 words
Inductive proximity switch comprising a high-frequency oscillator, wherein an oscillator coil is provided with an open core, saturation-sensitive to a magnetic field to be detected, in connection with an evaluation circuit, which detects the oscillation amplitude depending on the degree of the core saturation, and which, upon reaching of a certain amplitude value, triggers a switching process, wherein a foil-shaped anchor plate (4), made of a soft-magnetic metal alloy with a certain permeability, is coordinated to the open core (1) of the oscillator coil (2) under formation of an air gap (3), which anchor plate allows an oscillator current (I o ) to rise in a defined way upon intensification of the magnetic field from the damped state of said high frequency oscillator (10) or, respectively, upon a weakening of this field allows in a defined way to drop again in a damp state.
Claim 3
Dependent Claim
34 words
Inductive proximity switch according to claim 1, wherein the anchor plate (4), disposed at an air-gap distance, is provided with a particular geometric shape for the influencing the eddies of the magnetic flux lines.
Claim 4
Dependent Claim
32 words
Inductive proximity switch according to claim 1, wherein the anchor plate (4), disposed at an air-gap distance, has coordinated to itself or in its proximity at least one permanent magnet piece (7).
Claim 5
Dependent Claim
73 words
Inductive proximity switch according to claim 1, wherein the anchor plate, disposed at an air-gap distance, is formed to a wedge-shaped structure (8), which is directed with its wide side toward the magnetic field to be detected, and which is, by way of the oppositely disposed tip, supported like a point or like a line on the core wherein the core is shaped as a three-armed core or as a pot-shaped magnet core.
Claim 6
Dependent Claim
38 words
Inductive proximity switch according to claim 1, wherein the sensor coil is formed as an inserted air-gap inductor (13) switched on the input side or on the output side into a feed-back circuit of the high-frequency oscillator (10).
References Cited (Backward Citations)
US3271204A
Cited
DE1175327B
Cited
DE2829880A1
Cited
DE3244507A1
Cited
US4587486A
Cited
US4618823A
Cited
DE3423724A1
Cited
DE3423722A1
Cited
US4678994A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-02-18 | 1994-08-20 | 1995-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-18 | 1998-08-20 | 1999-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-18 | 2002-08-20 | 2003-02-19 | $7700.00 | Window Closed / Lapsed |