US3743905A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adjustable hospital beds
Assignee: Individual
•
Filing: 1971-09-14
•
Granted: 1973-07-03
•
Expires: 1991-09-14
Abstract
Abstract An electrical control system comprising a selector switch and a control switch in circuit with each other, said selector switch being movable to and from a position establishing a circuit between said control switch and said actuating means, said actuating means being a reversible electric motor, said electric motor having opposed windings, each of which is connected to the secondary of a transformer, the control circuit from each winding to the transformer, including a bi-directional gate, said gate being in circuit with a high frequency generator and with at least one capacitor interposed between said gate and said control switch.
Inventors
- 👤 R Goodman
- 👤 D Kilpatrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:41
CPC Classifications
F; F16; F16D; F16D11/00; F16D11/08; F16D11/10; A; A61; A61G; A61G7/00; A61G7/002; A61G7/018; H; H02; H02P; H02P23/00; H02P23/24
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
118 words
An electrical control system comprising a selector switch and a control switch in circuit with each other, said selector switch being movable to and from a position establishing a circuit between said control switch and an actuating means, said actuating means being a reversible electric motor, said electric motor having opposed windings, each of which is connected to the secondary of a transformer, the control circuit from each winding to the transformer, including a bi-directional gate, said gate being in circuit with a high frequency generator and with at least one capacitor interposed between said gate and said control switch, there being a plurality of 60 cycle per second-isolating capacitors interposed between said gate and said control switch.
Claim 2
Dependent Claim
118 words
An electrical control system comprising a selector switch and a control switch in circuit with each other, said selector switch being movable to and from a position establishing a circuit between said control switch and an actuating means, said actuating means being a reversible electric motor, said electric motor having opposed windings, each of which is connected to the secondary of a transformer, the control circuit from each winding to the transformer, including a bi-directional gate, said gate being in circuit with a high frequency generator and with at least one capacitor interposed between said gate and said control switch, there being a plurality of 60 cycle per second-isolating capacitors interposed between said gate and said control switch.
Claim 3
Dependent Claim
51 words
The system of claim 1 wherein said transformer comprises a primary winding positioned radially outward of the secondary winding, the secondary winding being electrically connected to a device to be controlled, a grounded copper foil shield encompassing said secondary winding, and low dielectric-constant spacers between said shield and said primary winding.
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) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |