US3873808A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Combination temperature and pressure relief valve with energy cutoff switch
Assignee: Individual
•
Filing: 1974-06-13
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Granted: 1975-03-25
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Expires: 1994-06-13
Abstract
Abstract A device for limiting the temperature and pressure of a fluid by controlling the electric current to a heating element. The device is mounted within a tank in which the fluid is heated and includes a pressure responsive piston movable within a cylinder against a compression spring opposing movement of the piston. When the pressure exceeds that for which the spring is designed, the piston compresses the spring and operates an actuator for a microswitch to break the electric circuit to the heating element. A temperature responsive element having an expansible core within the tank is connected to the piston and causes it to compress the spring and operates the actuator of the microswitch to break the electric circuit.
Inventors
- 👤 Thayer E Patton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:00
CPC Classifications
H; H05; H05B; H05B1/00; H05B1/02; H05B1/0202; H05B1/0216; H01; H01H; H01H35/00; H01H35/24; H01H35/38
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
157 words
A device for limiting the temperature and pressure of a fluid by controlling the electric current to an element (9) for heating the fluid which comprises a tank (10), a support assembly (13) for the device adapted to be inserted through a wall of the tank, the assembly including a cylinder (14) a pressure responsive piston (15) movable within the cylinder, a compression spring (16) opposing movement of the piston, an actuator (19) extending within the cylinder through the support assembly and adapted to be operated by movement of the piston, a microswitch (17) operable by the actuator to break an electric circuit (11) to the heating element, and a temperature responsive element (24) mounted within the tank, the element being connected to the piston to push the piston against the actuator of the microswitch to break the electric circuit to the heating element and a discharge conduit (20) for the overflow of fluid from the cylinder.
Claim 2
Independent Claim
157 words
A device for limiting the temperature and pressure of a fluid by controlling the electric current to an element (9) for heating the fluid which comprises a tank (10), a support assembly (13) for the device adapted to be inserted through a wall of the tank, the assembly including a cylinder (14) a pressure responsive piston (15) movable within the cylinder, a compression spring (16) opposing movement of the piston, an actuator (19) extending within the cylinder through the support assembly and adapted to be operated by movement of the piston, a microswitch (17) operable by the actuator to break an electric circuit (11) to the heating element, and a temperature responsive element (24) mounted within the tank, the element being connected to the piston to push the piston against the actuator of the microswitch to break the electric circuit to the heating element and a discharge conduit (20) for the overflow of fluid from the cylinder.
Claim 3
Dependent Claim
28 words
The device according to claim 1 in which the movement of the piston within the cylinder is lubricated and sealed against fluid pressure by durable plastic O-rings (23).
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) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |