US3874728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dental patients chair with a parallelogram supporting arm
Assignee: Siemens AG
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Filing: 1973-10-17
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Granted: 1975-04-01
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Expires: 1993-10-17
Abstract
Abstract A dental patient''s chair with a parallelogram supporting arm having one end linked to a base and another end carrying the seat of the chair and with an adjusting device for the height shifting of the chair. The invention is particularly characterized in that the adjusting device is a spindle drive actuated by electromotor and engaging the supporting arm preferably between two diagonally opposed link axes of the arm ends.
Inventors
- 👤 Rolf-Jurgen Weiland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:40
CPC Classifications
A; A61; A61G; A61G15/00; A61G15/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
105 words
A dental patients'' chair, comprising a base, a seat, a parallelogram carrying arm having one end connected with said base and the other end carrying said seat, the ends of said arm having diagonally opposed axles, and a device for height shifting of the seat, said device comprising an electrically driven spindle drive engaging said arm between said axles, said spindle drive comprising a motor, a rotary spindle driven by said motor, a bearing for the spindle connected with one of said axles and a screw nut engaging said spindle and connected with that end of the arm having the other one of said axles.
Claim 2
Dependent Claim
105 words
A dental patients'' chair, comprising a base, a seat, a parallelogram carrying arm having one end connected with said base and the other end carrying said seat, the ends of said arm having diagonally opposed axles, and a device for height shifting of the seat, said device comprising an electrically driven spindle drive engaging said arm between said axles, said spindle drive comprising a motor, a rotary spindle driven by said motor, a bearing for the spindle connected with one of said axles and a screw nut engaging said spindle and connected with that end of the arm having the other one of said axles.
Claim 3
Dependent Claim
41 words
A chair according to claim 1, wherein said bearing for the spindle is connected with the one axle which is connected with said base and wherein said driving motor for the spindle is located outside of said arm on said base.
Claim 4
Dependent Claim
24 words
A chair according to claim 2, having an intermidiate shaft connected with said motor and transmitting the drive of said motor to said spindle.
Claim 5
Dependent Claim
23 words
A chair according to claim 3, having an axle supporting said intermidiate shaft, the last-mentioned axle being in alignment with said one axle.
Claim 6
Dependent Claim
19 words
A chair according to claim 4, wherein the last-mentioned axle and said one axle form a continuous axle bearing.
Claim 7
Dependent Claim
16 words
A chair according to claim 4, wherein said intermediate shaft is removable from said one axle.
Claim 8
Dependent Claim
33 words
A chair according to claim 6, comprising a plug axle and two opposed bearings for said one axle and supporting said plug axle, said intermediate shaft being rotatably mounted upon said plug axle.
Claim 9
Dependent Claim
37 words
A chair according to claim 7, wherein said opposed bearings are axially movable and wherein said plug axle is a clamping screw for connecting the bearings of said one axle with the bearings of said intermediate shaft.
Claim 10
Dependent Claim
27 words
A chair according to claim 8, wherein said spindle drive comprises a safety switch operable when subjected to tension for interrupting the circuit of said driving motor.
Claim 11
Dependent Claim
39 words
A chair according to claim 9, wherein said spindle has transversely separated non-rotary portions, means interconnecting said portions when subjected to rotary moment and separating said portions when subjected to pull, said safety switch being located between said portions.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |