US4238699A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electro-magnetic devices
Assignee: ZF International UK Ltd
•
Filing: 1979-07-20
•
Granted: 1980-12-09
•
Expires: 1999-07-20
Abstract
Abstract An electro-magnetic actuator includes a pair of magnetizable members, the one member being hollow and surrounding the other member. The other member defines a plurality of axially spaced circumferentially extending first ribs which are of reducing diameter towards one end of the member. The one member is generally of tapering construction and defines second ribs complementary to the first ribs. Recesses are defined between adjacent pairs of first ribs and accommodate windings. When electric current is applied to the windings the members move axially relative to each other to reduce the reluctance of the magnetic paths defined by the two members.
Inventors
- 👤 Alec H. Seilly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:41
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/06; H01F7/08; H01F7/16; H01F7/1653
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
191 words
An electromagnetic actuator comprising a pair of members formed from magnetisable material, one of said members being hollow and being located about the other member, a plurality of circumferential ribs defined on the peripheral surface of the other member, the diameter of said ribs reducing from one end of the member to the other, recesses defined between adjacent ribs, windings disposed in some or all of said recesses, electrical connections between said windings, the windings or connections thereto being such that when electric current is passed therethrough the direction of current flow in one winding will be opposite to the direction of current flow in a winding in an adjacent recess, surfaces complementary to said ribs defined on the internal surface of the one member whereby when the other member is placed within the one member, the ribs on the other member will lie in close proximity to the surfaces respectively on the one member and when said windings are energised the adjacent ribs on said other member will be magnetically polarised and the two members will move to reduce the reluctance of the magnetic paths defined between the two members.
Claim 2
Dependent Claim
191 words
An electromagnetic actuator comprising a pair of members formed from magnetisable material, one of said members being hollow and being located about the other member, a plurality of circumferential ribs defined on the peripheral surface of the other member, the diameter of said ribs reducing from one end of the member to the other, recesses defined between adjacent ribs, windings disposed in some or all of said recesses, electrical connections between said windings, the windings or connections thereto being such that when electric current is passed therethrough the direction of current flow in one winding will be opposite to the direction of current flow in a winding in an adjacent recess, surfaces complementary to said ribs defined on the internal surface of the one member whereby when the other member is placed within the one member, the ribs on the other member will lie in close proximity to the surfaces respectively on the one member and when said windings are energised the adjacent ribs on said other member will be magnetically polarised and the two members will move to reduce the reluctance of the magnetic paths defined between the two members.
Claim 3
Dependent Claim
15 words
An actuator according to claim 1 in which said one member is of tapering form.
Claim 4
Dependent Claim
43 words
An actuator according to claim 1 in which said one member is provided with a plurality of ribs on its internal peripheral surface, the ribs on the one member being complementary to the ribs on the other member and defining said surfaces respectively.
Claim 5
Dependent Claim
22 words
An actuator according to claim 3 in which the internal and external surfaces of said one member are of stepped cylindrical form.
Claim 6
Dependent Claim
16 words
An actuator according to claim 3 in which said one member is of hollow truncated form.
Claim 7
Dependent Claim
19 words
An actuator according to claim 4 in which the ribs are located at the steps in the internal surface.
Claim 8
Dependent Claim
28 words
An actuator according to claim 3 in which the side surfaces of the ribs on the two members are spaced from each other by radially extending air gaps.
Claim 9
Dependent Claim
24 words
An actuator according to claim 3 in which the crests of the ribs are tapered on the sides thereof remote from the associated ribs.
Claim 10
Dependent Claim
22 words
An actuator according to claim 3 in which the associated ribs on the two members are spaced by longitudinally extending air gaps.
Claim 11
Dependent Claim
24 words
An actuator according to claim 2 in which said surfaces are defined by steps formed in the internal peripheral surface of said one member.
Claim 12
Dependent Claim
26 words
An actuator according to claim 1 in which the recesses are dimensioned so that the winding areas remain substantially constant throughout the length of the member.
Claim 13
Dependent Claim
23 words
An actuator according to claim 1 in which the circumferential area of each rib is substantially constant throughout the depth of the ribs.
Claim 14
Dependent Claim
22 words
An actuator according to claim 1 including a cover surrounding the one member, said cover defining bearing surfaces for said one member.
Claim 15
Dependent Claim
24 words
An actuator according to claim 13 in which said bearing surfaces are defined on longitudinal ribs defined on the internal surface of said cover.
References Cited (Backward Citations)
US3312842A
Cited
US3353040A
Cited
US4145625A
Cited
US4003013A
Cited
US4123691A
Cited
US4090097A
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 |