US4238698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnetic devices
Assignee: ZF International UK Ltd
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Filing: 1978-04-24
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Granted: 1980-12-09
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Expires: 1998-04-24
Abstract
Abstract An electromagnetic device comprises an outer annular member and an inner member, the two members each having a helical rib on their presented surfaces. Two presented side faces of the ribs define working surfaces and on one of the working surfaces is defined a groove which extends the length of the rib and the groove accommodates an electrical winding which when energized creates a pair of magnetic poles on the one working surface. The magnetic circuit of the poles includes the other working surface and the two surfaces move towards each other to reduce the magnetic reluctance thereby causing relative movement of the members.
Inventors
- 👤 Alec H. Seilly
- 👤 Dorian F. Mowbray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:56
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/16; H01F7/1653
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
121 words
An electromagnetic device comprising a pair of relatively movable members one of which is of annular form and surrounds the other member, said members defining opposed substantially cylindrical surface, a single helical magnetizable element on each of said surfaces respectively, each of said elements defining a working surface facing the working surface of the other element a groove formed in one working surface and an electrical conductor accommodated in said groove whereby when said conductor is energised said one working surface will form a pair of magnetic poles and the two members will move relative to each other in one direction so as to reduce the reluctance of the magnetic circuit formed between said poles and including the other working surface.
Claim 2
Dependent Claim
121 words
An electromagnetic device comprising a pair of relatively movable members one of which is of annular form and surrounds the other member, said members defining opposed substantially cylindrical surface, a single helical magnetizable element on each of said surfaces respectively, each of said elements defining a working surface facing the working surface of the other element a groove formed in one working surface and an electrical conductor accommodated in said groove whereby when said conductor is energised said one working surface will form a pair of magnetic poles and the two members will move relative to each other in one direction so as to reduce the reluctance of the magnetic circuit formed between said poles and including the other working surface.
Claim 3
Dependent Claim
53 words
A device according to claim 1 including a pair of grooves in said one working surface and a conductor in each of said grooves, said conductors forming an electrical winding extending from one end of the device along one groove and returning to said one end of the device along the other groove.
Claim 4
Dependent Claim
29 words
A device according to claim 1 in which the groove accommodates a plurality of conductors, the current flow in the conductors in said groove being in the same direction.
Claim 5
Dependent Claim
20 words
A device according to claim 1 in which said working surfaces extend substantially normal to the axis of the device.
Claim 6
Dependent Claim
16 words
A device according to claim 4 in which the groove extends substantially parallel to said axis.
Claim 7
Dependent Claim
47 words
A device according to claim 4 in which the element which defines said one working surface also defines a further working surface having a further groove locating a further conductor, whereby energisation of the further conductor will affect relative movement of the members in the opposite direction.
Claim 8
Dependent Claim
23 words
A device according to claim 1 in which said working surfaces are inclined relative to the normal to the axis of the device.
Claim 9
Dependent Claim
16 words
A device according to claim 7 in which said groove extends substantially normal to said axis.
Claim 10
Dependent Claim
31 words
A device according to claim 1 in which said working surfaces extends substantially parallel to the axis of the device, said groove extending substantially normal to the axis of the device.
Claim 11
Dependent Claim
21 words
A device according to claim 1 in which said one working surface is defined by the element on said other member.
References Cited (Backward Citations)
US3353040A
Cited
US4003013A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-09 | 1984-06-09 | 1984-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-09 | 1988-06-09 | 1988-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-09 | 1992-06-09 | 1992-12-09 | $7700.00 | Window Closed / Lapsed |