Patent US3604960A successfully refreshed from Google Patents.
US3604960A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dental drill handle
Assignee: Siemens AG
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Filing: 1970-01-26
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Granted: 1971-09-14
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Expires: 1990-01-26
Abstract
Abstract A dental drill handle has a small electric direct-current motor located in the handle and driven by an electronic commutator. The motor is cooled by compressed air. The structural part of the electronic commutator are all located within the handle in such manner that they are at least partly exposed to the flow of compressed air used for cooling the motor.
Inventors
- 👤 Erich Krestel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:03
CPC Classifications
H; H02; H02K; H02K29/00; H02K29/06; H02K29/08; A; A61; A61C; A61C1/00; A61C1/02; A61C1/06; H02K11/00; H02K11/30; H02K11/33
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
73 words
In a dental drill, a handle, a small electric direct-current motor located within said handle, an electronic commutator located within said handle, switch means located within said handle and operatively connecting said electric motor with said electronic commutator, and means connected with one end of said handle and supplying cooling compressed air to said electric motor and said electronic commutator, said compressed air flowing at least partly around portions of said electronic commutator.
Claim 2
Dependent Claim
73 words
In a dental drill, a handle, a small electric direct-current motor located within said handle, an electronic commutator located within said handle, switch means located within said handle and operatively connecting said electric motor with said electronic commutator, and means connected with one end of said handle and supplying cooling compressed air to said electric motor and said electronic commutator, said compressed air flowing at least partly around portions of said electronic commutator.
Claim 3
Dependent Claim
35 words
A device in accordance with claim 1, wherein said switch means are so located within the handle that they are exposed to at least a part of the compressed air flowing to cool said motor.
Claim 4
Dependent Claim
22 words
A device in accordance with claim 2, wherein said switch means are located between said electric motor and said compressed-air supplying means.
Claim 5
Dependent Claim
43 words
A device in accordance with claim 3, wherein said handle has a central passage for the flow of compressed air and wherein said switch means comprise transistors located circularly around said passage and having cooling surfaces exposed to the flow of compressed air.
Claim 6
Dependent Claim
13 words
A device in accordance with claim 4, wherein said cooling surfaces extend inwardly.
Claim 7
Dependent Claim
55 words
A device in accordance with claim 5, wherein said electric motor comprises a stator and a rotor and wherein said electric commutator comprises steering electrodes mounted upon the front side of said motor and catcher plates connected with said steering electrodes, said catcher plates receiving the stray flow at the front side of the rotor.
Claim 8
Dependent Claim
29 words
A device in accordance with claim 6, wherein said switch means further comprise means producing a constant voltage for said steering electrodes and amplifiers connected with the last-mentioned means.
Claim 9
Dependent Claim
35 words
A device in accordance with claim 7, further comprising a switch carried by said handle and means connecting said switch with said steering electrodes for reversing the direction of current flow in said steering electrodes.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |