Patent US3729020A successfully refreshed from Google Patents.
US3729020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure relief and drain valve
Assignee: Individual
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Filing: 1971-04-26
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Granted: 1973-04-24
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Expires: 1991-04-26
Abstract
Abstract A locomotive cooling system has radiators mounted above the normal coolant level during engine shutdown in the engine and water tank so as to drain the radiators when the engine stops to avoid the possibility of freezing the water therein. An automatic pressure relief and overflow valve is provided which is open during engine shutdown to drain excess water from the cooling system so as to prevent the retaining of any coolant in the radiators. When the engine is operating, the valve is normally closed by engine lubricating oil pressure to permit normal pressure buildup in the engine cooling system. However, the valve opens to relieve excess pressure in the cooling system. Manual opening means are also provided to relieve system pressure during engine operation.
Inventors
- 👤 L Koci
- 👤 H Suarez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:10
CPC Classifications
F; F01; F01P; F01P11/00; F01P11/14; F01P11/20; F16; F16K; F16K15/00; F16K15/02; F16K15/06; F16K15/063; F16K15/18; F16K15/182; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7837; Y10T137/7876; Y10T137/7904; Y10T137/7905
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
196 words
A pressure relief and automatic drain valve for use in an engine cooling system to control the level and pressure of the coolant, said valve comprising: a valve body, a valve element reciprocably movable in said body between open and closed positions, first biasing means urging said valve element in a closing direction and yieldable to permit said valve to be opened in response to a predetermined pressure of fluid acting against said valve element, actuating means connectable with said valve element to move it in an opening direction, said valve element and said actuating means being arranged for limited relative movement to permit opening movement of said valve element without a corresponding movement of said actuating means, and second biasing means yieldably acting on said actuating means and urging it in a valve opening direction so as to cause said actuating means to open said valve irrespective of the aCtion of said first biasing means, said actuating means being responsive to a secondary fluid pressure to move said actuating means in a valve closing direction against the force of said second biasing means and thereby permit closing of said valve by said first biasing means.
Claim 2
Dependent Claim
196 words
A pressure relief and automatic drain valve for use in an engine cooling system to control the level and pressure of the coolant, said valve comprising: a valve body, a valve element reciprocably movable in said body between open and closed positions, first biasing means urging said valve element in a closing direction and yieldable to permit said valve to be opened in response to a predetermined pressure of fluid acting against said valve element, actuating means connectable with said valve element to move it in an opening direction, said valve element and said actuating means being arranged for limited relative movement to permit opening movement of said valve element without a corresponding movement of said actuating means, and second biasing means yieldably acting on said actuating means and urging it in a valve opening direction so as to cause said actuating means to open said valve irrespective of the aCtion of said first biasing means, said actuating means being responsive to a secondary fluid pressure to move said actuating means in a valve closing direction against the force of said second biasing means and thereby permit closing of said valve by said first biasing means.
Claim 3
Dependent Claim
210 words
A pressure relief and drain valve for use in an engine cooling system to control the level and pressure of the engine coolant, said valve comprising: a valve body, a valve element reciprocably movable in said body between open and closed positions, a first spring urging said valve element in a closing direction and yieldable to permit the valve to be opened by excessive coolant pressure acting on the valve element, an actuator connectable with said valve element and adapted to move it in an opening direction, said valve element and said actuator being arranged for limited relative movement to permit opening movement of said valve element without a corresponding movement of said actuator, a second spring acting on said actuator and urging it in a valve opening direction so as to cause said actuator to open said valve irrespective of the action of said first spring, said actuator including a hydraulic piston responsive to fluid pressure from a second source to overcome the force of said second spring and move said actuator in a valve closing direction to thereby permit the closing of said valve by said first spring, and a manual actuator in said body and actuable to open said valve against the force of said first spring.
Claim 4
Dependent Claim
210 words
A pressure relief and drain valve for use in an engine cooling system to control the level and pressure of the engine coolant, said valve comprising: a valve body, a valve element reciprocably movable in said body between open and closed positions, a first spring urging said valve element in a closing direction and yieldable to permit the valve to be opened by excessive coolant pressure acting on the valve element, an actuator connectable with said valve element and adapted to move it in an opening direction, said valve element and said actuator being arranged for limited relative movement to permit opening movement of said valve element without a corresponding movement of said actuator, a second spring acting on said actuator and urging it in a valve opening direction so as to cause said actuator to open said valve irrespective of the action of said first spring, said actuator including a hydraulic piston responsive to fluid pressure from a second source to overcome the force of said second spring and move said actuator in a valve closing direction to thereby permit the closing of said valve by said first spring, and a manual actuator in said body and actuable to open said valve against the force of said first spring.
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) | 1976-04-23 | 1976-10-23 | 1977-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-23 | 1980-10-23 | 1981-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-23 | 1984-10-23 | 1985-04-24 | $7700.00 | Window Closed / Lapsed |