US3668596A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic keys
Assignee: Rafi Raimund Finsterholzl Elektrotechnische Spezialfabrik
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Filing: 1970-10-26
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Granted: 1972-06-06
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Expires: 1990-10-26
Abstract
Abstract A magnetic key suitable for use with electronic equipment comprises a magnetically controllable semiconductor device mounted between two soft iron pole pieces, and a permanent magnet movable relative to the device. The magnet is carried by a slide movable between two positions and biased by a spring towards one of the positions. In one position only a substantial part of the magnetic flux of the magnet passes through the device, so the condition of the device can be controlled by movement of the slide.
Inventors
- 👤 Rudolf Hubrich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:24
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/94; H03K17/965; H03K17/97; H03K17/972; H03K17/51; H03K17/90; H03K3/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
139 words
A magnetic key comprising a casing, a slide mounted in the casing for linear movement between two positions, spring means urging the slide towards one of said positions, a permanent magnet carried by the slide and having a North pole and a South pole aligned in the direction of said movement of the slide, two pole pieces mounted within the casing, a magnetically controllable semiconductor device mounted between the pole pieces, the arrangement being such that in one of said positions of the slide said two poles of the magnet are adjacent to the two pole pieces respectively whereby a substantial part of the magnetic flux of the magnet passes through said device, and in the other of said positions of the slide said two poles of the magnet are both adjacent to one of the two pole pieces.
Claim 2
Dependent Claim
139 words
A magnetic key comprising a casing, a slide mounted in the casing for linear movement between two positions, spring means urging the slide towards one of said positions, a permanent magnet carried by the slide and having a North pole and a South pole aligned in the direction of said movement of the slide, two pole pieces mounted within the casing, a magnetically controllable semiconductor device mounted between the pole pieces, the arrangement being such that in one of said positions of the slide said two poles of the magnet are adjacent to the two pole pieces respectively whereby a substantial part of the magnetic flux of the magnet passes through said device, and in the other of said positions of the slide said two poles of the magnet are both adjacent to one of the two pole pieces.
Claim 3
Dependent Claim
14 words
A key according to claim 1 wherein the casing is made of plastics material.
Claim 4
Dependent Claim
33 words
A key according to claim 2 wherein the casing has on the inside two grooves disposed parallel to said direction, and the slide is provided with two rib-like projections slidable in respective grooves.
Claim 5
Dependent Claim
14 words
A key according to claim 3 wherein the slide is made of plastics material.
Claim 6
Dependent Claim
12 words
A key according to claim 1 wherein the magnet is generally U-shaped.
Claim 7
Dependent Claim
19 words
A key according to claim 1 wherein the two pole pieces are plate-shaped and made of magnetically soft iron.
Claim 8
Dependent Claim
58 words
A key according to claim 6 wherein one pole piece, as measured in said direction, is substantially longer than the other pole piece, and said one pole piece is arranged in the casing such that in said other of said positions of the slide said two poles of the magnet are both adjacent to said one pole piece.
Claim 9
Dependent Claim
48 words
A key according to claim 7 wherein the end faces of the two pole pieces, which face towards one another, are parallel with one another and substantially perpendicular to said direction, said device in plate-shaped, and the two large surfaces of said device extend perpendicular to said direction.
Claim 10
Dependent Claim
22 words
A key according to claim 8 wherein the cross section of one pole piece is tapered in the direction of said device.
Claim 11
Dependent Claim
32 words
A key according to claim 9 wherein the end face of the tapered pole piece has at most one third of the cross-sectional area of the non-tapered part of said pole piece.
References Cited (Backward Citations)
US3571774A
Cited
US3590134A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |