US4004262A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electromagnet for providing balanced friction face pressures on an armature in a vehicle electric brake system
Assignee: Individual
•
Filing: 1975-03-11
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Granted: 1977-01-18
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Expires: 1995-03-11
Abstract
Abstract An electromagnet for use in electric brakes and similar type clutches which will apply balanced friction face pressure against a rotating armature face despite the additional, externally imposed, pressures which are directed to its leading edge by tipping moments existing at its point of restraint. The electromagnet departs from conventional design in that a non-magnetic wear or friction face replaces a sufficient area of the outer magnetic pole face on the leading edge of the electromagnet to insure that the externally imposed forces on the leading edge of the electromagnet are balanced by the magnetic linkage forces existing in the rest of the electromagnet faces. Balanced friction face pressure greatly increases the performance and useful life of an electromagnet and the electric brake or clutch system which it actuates.
Inventors
- 👤 Leroy K. Grove
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:24
CPC Classifications
F; F16; F16D; F16D63/00; F16D63/002; H; H01; H01F; H01F7/00; H01F7/06; H01F7/08
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
170 words
An electromagnet for use in electric brakes, clutches and the like having an armature rotating relative to said electromagnet and an actuating arm attached to and restraining said electromagnet, comprising a body of low reluctance magnetic material having an inner pole and an outer pole defining a cavity and having leading and trailing edges relative to the normal forward rotation of the armature, an electric coil disposed in said cavity, said poles having planar faces for engaging the armature, with the leading edge of said outer pole which first engages the oncoming armature face having a recess therein forming a non-magnetic sector, and a nonmagnetic wear member in said cavity and recess for engaging the armature, said non-magnetic sector on the leading edge of said outer pole being of a size of at least 45° taken from a point on the center line spaced from the leading edge equal in distance to the distance from the center line to the lateral side edges at right angles to said center line.
Claim 2
Dependent Claim
170 words
An electromagnet for use in electric brakes, clutches and the like having an armature rotating relative to said electromagnet and an actuating arm attached to and restraining said electromagnet, comprising a body of low reluctance magnetic material having an inner pole and an outer pole defining a cavity and having leading and trailing edges relative to the normal forward rotation of the armature, an electric coil disposed in said cavity, said poles having planar faces for engaging the armature, with the leading edge of said outer pole which first engages the oncoming armature face having a recess therein forming a non-magnetic sector, and a nonmagnetic wear member in said cavity and recess for engaging the armature, said non-magnetic sector on the leading edge of said outer pole being of a size of at least 45° taken from a point on the center line spaced from the leading edge equal in distance to the distance from the center line to the lateral side edges at right angles to said center line.
Claim 3
Dependent Claim
36 words
An electromagnet for brakes and clutches as defined in claim 1 in which said non-magnetic wear member projects beyond the leading edge of said outer pole and is seated in a recess in said leading edge.
Claim 4
Dependent Claim
29 words
An electromagnet for brakes and clutches as defined in claim 1 in which said outer pole is cylindrical in shape and said wear member projects beyond the periphery thereof.
Claim 5
Dependent Claim
27 words
An electromagnet for brakes and clutches as defined in claim 3 in which the armature contact face of the poles is provided with alternate lands and recesses.
Claim 6
Dependent Claim
157 words
An electromagnet for brakes and clutches having an armature, comprising a cylindrical center pole and an annular outer pole spaced from said center pole and forming a recess therebetween, leading and trailing edges on said outer pole relative to the normal forward rotation of said armature with the leading edge of said outer pole first engaging the oncoming armature face, and electric coil in said recess, a flat friction member disposed in said recess and having its outer surface on substantially the same plane as the armature contact surfaces of said poles, a recess in the face of the leading edge of the outer pole of a depth approximately the same as the thickness of said friction member and extending throughout at least 45° of said annular outer pole, and an extension on said friction member disposed in said recess in the face of said outer pole and forming a substantially nonmagnetic sector in said leading edge.
Claim 7
Dependent Claim
157 words
An electromagnet for brakes and clutches having an armature, comprising a cylindrical center pole and an annular outer pole spaced from said center pole and forming a recess therebetween, leading and trailing edges on said outer pole relative to the normal forward rotation of said armature with the leading edge of said outer pole first engaging the oncoming armature face, and electric coil in said recess, a flat friction member disposed in said recess and having its outer surface on substantially the same plane as the armature contact surfaces of said poles, a recess in the face of the leading edge of the outer pole of a depth approximately the same as the thickness of said friction member and extending throughout at least 45° of said annular outer pole, and an extension on said friction member disposed in said recess in the face of said outer pole and forming a substantially nonmagnetic sector in said leading edge.
Claim 8
Dependent Claim
28 words
An electromagnet for brakes and clutches as defined in claim 5 in which lands and recesses are provided in the armature contact surface in one of said poles.
Claim 9
Dependent Claim
28 words
An electromagnet for brakes and clutches as defined in claim 5 in which lands and recesses are provided in the armature contact surfaces of both of said poles.
Claim 10
Dependent Claim
29 words
An electromagnet for brakes and clutches as defined in claim 5 in which said coil is on a bobbin and said friction member is formed integrally with said bobbin.
Claim 11
Dependent Claim
27 words
An electromagnet for brakes and clutches as defined in claim 5 in which said extension on said friction member projects beyond the periphery of the outer pole.
Claim 12
Dependent Claim
31 words
An electromagnet for brakes and clutches as defined in claim 7 in which said lands and recesses in said poles are curved and are concentric with the center of the magnet.
Claim 13
Dependent Claim
62 words
An electromagnet for brakes and clutches as defined in claim 5 in which the recess in the contact face of the outer pole and the thickness of the friction member in said recess are sufficient to reduce the magnetic forces at the forward edge of the magnet to a point substantially less than the magnetic forces throughout the remainder of the magnet.
Claim 14
Dependent Claim
26 words
An electromagnet for brakes and clutches as defined in claim 7 in which the friction material consists of polycarbonate plastic material impregnated with an abrasive material.
Claim 15
Dependent Claim
174 words
An electromagnet for use in electric brakes, clutches and the like having an armature rotating relative to said electromagnet and an actuating arm attached to and restraining said electromagnet, comprising a ferrous body having a cavity defines by an inner pole and an outer pole and having leading and trailing edges relative to the normal forward rotation of the armature, said poles having planar faces for engaging the armature with the leading edge section, the leading edge of said outer pole first engaging the oncoming armature face having a recess forming a non-magnetic sector, an electric coil assembly disposed in said cavity in said body, and a non-magnetic friction member disposed in said cavity and recess for engaging the armature, said non-magnetic sector on the leading edge of said outer pole being of a size of at least 45° taken from a point on the center line spaced from the leading edge equal in distance to the distance from the center line to the lateral side edges at right angles to said center line.
Claim 16
Dependent Claim
174 words
An electromagnet for use in electric brakes, clutches and the like having an armature rotating relative to said electromagnet and an actuating arm attached to and restraining said electromagnet, comprising a ferrous body having a cavity defines by an inner pole and an outer pole and having leading and trailing edges relative to the normal forward rotation of the armature, said poles having planar faces for engaging the armature with the leading edge section, the leading edge of said outer pole first engaging the oncoming armature face having a recess forming a non-magnetic sector, an electric coil assembly disposed in said cavity in said body, and a non-magnetic friction member disposed in said cavity and recess for engaging the armature, said non-magnetic sector on the leading edge of said outer pole being of a size of at least 45° taken from a point on the center line spaced from the leading edge equal in distance to the distance from the center line to the lateral side edges at right angles to said center line.
Claim 17
Dependent Claim
23 words
The electromagnet as set forth in claim 13 wherein the armature contact face of the poles is provided with alternate lands and recesses.
Claim 18
Dependent Claim
118 words
The electromagnet as set forth in claim 13 wherein said non-magnetic friction material disposed in the annular cavity extends outward toward the leading edge of the electromagnet to serve as the non-magnetic friction material, said non-magnetic friction material being seated on said outer pole in said recess, and said non-magnetic friction material consists of a slow wearing, high coefficient of friction, brake lining type of material and the lands in the armature contact faces of the poles are relatively narrow to provide that the faces of the poles are wearable on contact with said armature at a rate greater than said friction material for maintaining said friction material as the primary contact of the electromagnet with the armature.
References Cited (Backward Citations)
US3476223A
Cited
US3760909A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-01-18 | 1980-07-19 | 1981-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-18 | 1984-07-19 | 1985-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-18 | 1988-07-19 | 1989-01-18 | $7700.00 | Window Closed / Lapsed |