Patent US3900952A successfully refreshed from Google Patents.
US3900952A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical motor, particularly for driving dental handpieces and angular pieces
Assignee: Siemens AG
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Filing: 1973-11-19
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Granted: 1975-08-26
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Expires: 1993-11-19
Abstract
Abstract An electric motor for driving dental handpieces, comprising a rotary part consisting of a rotary body and rotary shaft. The said rotary part is carried by an air cushion formed by the introduction of compressed air into an air space between the rotary part and a fixed part of the said motor.
Inventors
- 👤 Hermann Landgraf
- 👤 Eugen Hohmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:46
CPC Classifications
H; H02; H02K; H02K7/00; H02K7/08; H02K7/086; H02K7/088; A; A61; A61C; A61C1/00; A61C1/02; A61C1/06; A61C1/08; A61C1/18; A61C1/181; H02K7/14; H02K7/145; F; F16; F16C; F16C2380/00; F16C2380/26
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
125 words
An electric motor for driving dental hand-pieces, comprising a permanent magnet stator arranged in a substantially cYlindrical housing, and a rotor body carrying a rotor shaft and mounted in a compressed air bearing, wherein said permanent magnet stator is formed by several annular discs of permanent magnetic non ductile material and intermediate rings of material softer than that of said discs and arranged therebetween, said intermediate rings having conduits for supplying compressed air to said compressed air bearing arranged in radial direction, and wherein the air gap of said air bearing lies predominantly in the magnetic air gap between said rotor body and said stator, the compressed air for the formation of said bearing being conducted into said air gap through said radially arranged conduits.
Claim 2
Dependent Claim
125 words
An electric motor for driving dental hand-pieces, comprising a permanent magnet stator arranged in a substantially cYlindrical housing, and a rotor body carrying a rotor shaft and mounted in a compressed air bearing, wherein said permanent magnet stator is formed by several annular discs of permanent magnetic non ductile material and intermediate rings of material softer than that of said discs and arranged therebetween, said intermediate rings having conduits for supplying compressed air to said compressed air bearing arranged in radial direction, and wherein the air gap of said air bearing lies predominantly in the magnetic air gap between said rotor body and said stator, the compressed air for the formation of said bearing being conducted into said air gap through said radially arranged conduits.
Claim 3
Dependent Claim
38 words
The electric motor of claim 1, wherein the discs and the intermediate rings form, with their generated surfaces in the said housing, a gap extending along the motor housing for supplying compressed air to the compressed air bearing.
Claim 4
Dependent Claim
72 words
The electric motor according to claim 1, to whose rear end a feed means is connectable by a connecting means to supply compressed air and electrical energy, and wherein between said housing and stator guide means are arranged to return the air flowing out of the compressed air bearing between said housing and stator, and separately from the supplied compressed air, to the end of the motor directed towards said connecting means.
Claim 5
Dependent Claim
61 words
The electric motor according to claim 1, wherein at least one of the end faces of the said rotor body forms one half of an additional compressed air bearing axially supporting the said rotor, and whose other half is a ring fitting it, fixed in the said stator housing, and containing compressed air feed conduits for the additional compressed air bearing.
Claim 6
Dependent Claim
23 words
The electric motor of claim 4, wherein the said ring has means for adjustment of the bearing gap of the said additional bearing.
References Cited (Backward Citations)
US3124962A
Cited
US2905149A
Cited
US3243238A
Cited
US3439422A
Cited
US3582228A
Cited
US3472323A
Cited
US3586397A
Cited
US3584629A
Cited
US3578872A
Cited
US3677351A
Cited
US3758228A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |