US3858611A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Step opening thermostatic control device
Assignee: Robertshaw Controls Co
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Filing: 1973-05-07
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Granted: 1975-01-07
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Expires: 1993-05-07
Abstract
Abstract A step opening thermostatic control device includes a main valve and a step valve for controlling flow through a flow passage between inlet and outlet ports of a casing, the main valve including a main valve stem carrying a valve seat for the step valve, and the step valve including a step valve stem extending through the main valve stem and carrying a step valve member biased toward the step valve seat such that movement of the step valve stem by temperature responsive means initially opens the step valve with opening of the main valve being delayed after the initial opening of the step valve.
Inventors
- 👤 George L Thayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:44
CPC Classifications
F; F16; F16K; F16K31/00; F16K31/44; F16K31/56; F03; F03G; F03G7/00; F03G7/06; F03G7/061; F03G7/06114; G; G05; G05D; G05D23/00; G05D23/19; G05D23/1919; G05D23/1921; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86928; Y10T137/86936; Y10T137/86944; Y10T137/86976; Y10T137/86984
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
400 words
A step opening thermostatic control device comprising a casing having inlet and outlet means and a flow passage therebetween; main valve means movable between open and closed positions to control flow through said flow passage, said main valve means including a main valve seat disposed in said flow passage, a main valve member cooperating with said main valve seat and a hollow main valve stem carrying said main valve member; step valve means movable between open and closed positions to control flow through said flow passage, said step valve means including a step valve seat carried on said main valve stem, a step valve member cooperating with said step valve seat and a step valve stem carrying said step valve member and extending through said main valve stem; temperature responsive means having an actuated state and a released state; a first coiled spring mounted in compression between said casing and said step valve member and biasing said main valve means and said step valve means toward said closed positions; and closed positions; and a second coiled spring mounted in compression between said main valve stem and said step valve stem and biasing said step valve member toward said step valve seat, said main valve member having a movement away from said main valve seat to open said main valve means, which movement causes said step valve seat to engage said step valve member to close said step valve means; said temperature responsive means moving said step valve stem to move said step valve member away from said step valve seat against the force of said first and second spring means to initially open said step valve means when said temperature responsive means moves to said actuaTed state, and said main valve member being moved away from said main valve seat by said second spring means and said temperature responsive means after said initial opening of said step valve means to open said main valve means whereby said thermostatic control device has a step opening characteristic with the opening of said main valve means delayed after the initial opening of said step valve means, said temperature responsive means includes snap acting means mounted on said casing and a heat-motor thermostat operating said snap acting means, said heat-motor operator including a rod having a high thermal coefficient of expansion engaging said snap acting means and a heating coil for heating said rod.
Claim 2
Dependent Claim
400 words
A step opening thermostatic control device comprising a casing having inlet and outlet means and a flow passage therebetween; main valve means movable between open and closed positions to control flow through said flow passage, said main valve means including a main valve seat disposed in said flow passage, a main valve member cooperating with said main valve seat and a hollow main valve stem carrying said main valve member; step valve means movable between open and closed positions to control flow through said flow passage, said step valve means including a step valve seat carried on said main valve stem, a step valve member cooperating with said step valve seat and a step valve stem carrying said step valve member and extending through said main valve stem; temperature responsive means having an actuated state and a released state; a first coiled spring mounted in compression between said casing and said step valve member and biasing said main valve means and said step valve means toward said closed positions; and closed positions; and a second coiled spring mounted in compression between said main valve stem and said step valve stem and biasing said step valve member toward said step valve seat, said main valve member having a movement away from said main valve seat to open said main valve means, which movement causes said step valve seat to engage said step valve member to close said step valve means; said temperature responsive means moving said step valve stem to move said step valve member away from said step valve seat against the force of said first and second spring means to initially open said step valve means when said temperature responsive means moves to said actuaTed state, and said main valve member being moved away from said main valve seat by said second spring means and said temperature responsive means after said initial opening of said step valve means to open said main valve means whereby said thermostatic control device has a step opening characteristic with the opening of said main valve means delayed after the initial opening of said step valve means, said temperature responsive means includes snap acting means mounted on said casing and a heat-motor thermostat operating said snap acting means, said heat-motor operator including a rod having a high thermal coefficient of expansion engaging said snap acting means and a heating coil for heating said rod.
Claim 3
Dependent Claim
85 words
A step opening thermostatic control device as recited in claim 1 wherein said flow passage in said casing includes an inlet chamber disposed on an opposite side of said main valve seat from said outlet means, and said main valve member is disposed in said inlet chamber such that the pressure differential across said main valve member maintains said main valve member in engagement with said main valve seat after initial opening of said step valve means to delay opening of said main valve means.
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) | 1978-01-06 | 1978-07-08 | 1979-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-06 | 1982-07-08 | 1983-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-06 | 1986-07-08 | 1987-01-07 | $7700.00 | Window Closed / Lapsed |