Patent US3622747A successfully refreshed from Google Patents.
US3622747A
Expired / Lapsed
US
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Hydraulic transmission systems
Assignee: Cibie Projecteurs SA
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Filing: 1969-07-09
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Granted: 1971-11-23
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Expires: 1989-07-09
Abstract
Abstract A hydraulic transmission circuit includes an electric-heating circuit within it. The heating circuit includes a heating wire and a temperature-responsive switch for opening and closing the heating circuit in response to the temperature of the hydraulic liquid. The switch may comprise bimetallic strips having magnets which attract each other at the ends of the strips carrying the switch contacts.
Inventors
- 👤 Pierre Cibie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:41
CPC Classifications
F; F15; F15B; F15B7/00; F15B7/06; F15B7/10; Y; Y10; Y10T; Y10T137/00; Y10T137/6416; Y10T137/6606
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
128 words
A hydraulic transmission circuit comprising: a. two spaced-apart liquid displacement members, b. means for transmitting displaced liquid between said members, said means including I. a tube extending between said members, II. said tube being filled with hydraulic liquid, and c. means for maintaining liquid displaced within said hydraulic transmission circuit substantially immune to ambient temperature variations, said means including: I. an electric-heating element within said tube and extending for substantially the entire length of said tube, and II. thermostatically controlled switch means, responsive to small temperature variations in the hydraulic liquid in said tube for controlling the energization of said heating element, whereby the temperature of the hydraulic liquid is substantially maintained within a narrow temperature range determined by said thermostatically controlled switch regardless of ambient temperature variations.
Claim 2
Dependent Claim
128 words
A hydraulic transmission circuit comprising: a. two spaced-apart liquid displacement members, b. means for transmitting displaced liquid between said members, said means including I. a tube extending between said members, II. said tube being filled with hydraulic liquid, and c. means for maintaining liquid displaced within said hydraulic transmission circuit substantially immune to ambient temperature variations, said means including: I. an electric-heating element within said tube and extending for substantially the entire length of said tube, and II. thermostatically controlled switch means, responsive to small temperature variations in the hydraulic liquid in said tube for controlling the energization of said heating element, whereby the temperature of the hydraulic liquid is substantially maintained within a narrow temperature range determined by said thermostatically controlled switch regardless of ambient temperature variations.
Claim 3
Dependent Claim
58 words
A hydraulic transmission circuit as defined in claim 1 wherein said thermostatically controlled switch means comprises at least one bimetallic strip having a free end, a first electric contact mounted at said end connected to said electric heating element, and a second electric contact connnected to said heating element and adapted to be engaged by said first contact.
Claim 4
Dependent Claim
37 words
A hydraulic transmission circuit as defined in claim 2 including a magnetic element fixed with respect to said second contact, and a permanent magnet carried by said bimetallic strip adapted to be attracted to said magnetic element.
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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) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |