US3699778A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal expansion valve with rapid pressure equalizer
Assignee: Eaton Corp
•
Filing: 1971-03-29
•
Granted: 1972-10-24
•
Expires: 1991-03-29
Abstract
Abstract The thermostatic expansion valve is provided with an internal by-pass capable of providing rapid equalization of the pressure between the condenser and evaporator when the compressor shuts down. The valve controlling the refrigerant flow has an internal cavity in communication with the condenser pressure and a by-pass port in communication with the evaporator. The valve, urged towards the closed position by a spring, is actuated by the diaphragm through push pins. The push pins normally close the bypass port, either by the lower end of one or more of the push pins cooperating with a seat located at the by-pass port outlet or a valve means (e.g. a flanged collar which guides the valve) interposed the push pins and the by-pass port. With the valve in the closed position, the push pin(s) or valve means can be lifted off the by-pass port by condenser pressure in the cavity, as forces across the diaphragm equalize after shutdown of the compressor. The system pressure is then rapidly equalized through the by-pass port.
Inventors
- 👤 Charles D Orth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:37
CPC Classifications
F; F16; F16K; F16K17/00; F16K17/18; F16K17/19; F25; F25B; F25B41/00; F25B41/30; F25B41/31; F25B41/33; F25B41/335
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
197 words
In a thermostatic expansion valve having a body provided with an inlet and an outlet separated by a first seat, a control valve cooperating with the first seat to regulate flow from the inlet to the outlet, a diaphragm having one side subjected to a pressure which is a function of evaporator outlet temperature and its other side subjected to the pressure in said valve outlet means connecting the diaphragm to the valve to actuate the valve, a spring biasing the valve in the closing direction in opposition to the diaphragm, the improvement comprising: a chamber in said control valve; a conduit between the chamber and said inlet whereby inlet pressure prevails in said chamber; a port leading from said chamber to said valve outlet; a by-pass valve means controlling flow through said port, the pressure in said chamber acting on the by-pass valve means in a valve opening direction; and said by-pass valve means being held closed by the diaphragm force until the spring closes the control valve on the first seat and the pressures across the diaphragm equalize sufficiently for the chamber pressure to open the by-pass valve means and equalize inlet and outlet pressures.
Claim 2
Dependent Claim
197 words
In a thermostatic expansion valve having a body provided with an inlet and an outlet separated by a first seat, a control valve cooperating with the first seat to regulate flow from the inlet to the outlet, a diaphragm having one side subjected to a pressure which is a function of evaporator outlet temperature and its other side subjected to the pressure in said valve outlet means connecting the diaphragm to the valve to actuate the valve, a spring biasing the valve in the closing direction in opposition to the diaphragm, the improvement comprising: a chamber in said control valve; a conduit between the chamber and said inlet whereby inlet pressure prevails in said chamber; a port leading from said chamber to said valve outlet; a by-pass valve means controlling flow through said port, the pressure in said chamber acting on the by-pass valve means in a valve opening direction; and said by-pass valve means being held closed by the diaphragm force until the spring closes the control valve on the first seat and the pressures across the diaphragm equalize sufficiently for the chamber pressure to open the by-pass valve means and equalize inlet and outlet pressures.
Claim 3
Dependent Claim
52 words
A thermostatic expansion valve according to claim 1 in which the control valve includes a second seat located at the outlet of said port and the means connecting the diaphragm and the control valve includes push pins, one of which cooperates with said second seat to act as said by-pass valve means.
Claim 4
Dependent Claim
31 words
A thermostatic expansion valve according to claim 2 in which the control valve is in the general form of a needle valve and the conduit is central of the needle valve.
Claim 5
Dependent Claim
58 words
A thermostatic expansion valve according to claim 1 in which the means connecting the diaphragm and the control valve includes push pins, said by-pass valve means being positioned between the push pins and the control valve whereby the spring acting on the control valve holds the by-pass valve means closed until the control valve closes on its seat.
Claim 6
Dependent Claim
20 words
A thermostatic expansion valve according to claim 4 in which the by-pass valve means comprises a plate overlying the port.
Claim 7
Dependent Claim
35 words
A thermostatic expansion valve according to claim 5 in which the control valve is in the general form of a needle valve and the conduit is central of the needle valve, said plate being annular.
References Cited (Backward Citations)
US2967403A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |