US3742722A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermostatic expansion valve for refrigeration systems
Assignee: Spartan Valve Co
•
Filing: 1972-02-08
•
Granted: 1973-07-03
•
Expires: 1992-02-08
Abstract
Abstract A thermostatic expansion valve for a refrigeration system including a piston movable in a cylindrical chamber formed in the valve body, a first plastic seal carried by the piston and slidably yet sealably engaging the chamber wall, a second plastic seal carried by the piston and selectively engaging a valve seat to close the valve port, the piston having opposed first and second pressure surfaces, the first pressure surface being defined by the valve port and subjected to the pressure in the valve passage at one side of the valve port tending to move the piston toward the open position, and means subjecting the second pressure surface to the same pressure exerted on the first pressure surface and tending to urge the piston toward the closed position. The piston is provided with a nose, constituting at least a part of the first pressure surface, which extends beyond the second plastic seal and through the valve port, the nose being selectively shaped and contoured to vary the nominal capacity of the valve. The piston nose is detachably connected to the piston so that noses of different shapes and contours can be selectively attached to change such nominal valve capacity. The piston assembly includes adjacent first and second piston bodies, the first plastic seal being located against one end of the first piston body, and the second plastic seal being sandwiched between the other end of the first piston body and the second piston body, and the nose being provided with a threaded shank threadedly engaging the first and second piston bodies to clamp the piston bodies and seals together. A push rod extends through a body bore and operatively interconnects a flexible motor element with the valve means for moving the valve means. The body includes a guide portion through which the rod bore extends, the guide portion extending into the valve passage and spaced from the valve means, and being provided with an annular edge about the body bore and push rod. A seal collar of plastic material is slidably yet sealably mounted with a close fit on the push rod between the guide portion and the valve means. A spring about the push rod urges the seal collar against the annular edge to seal the clearance of the body bore between the push rod and the guide portion.
Inventors
- 👤 J Leimbach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:52
CPC Classifications
F; F25; F25B; F25B41/00; F25B41/30; F25B41/31; F25B41/33; F25B41/335
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
345 words
In a refrigeration system having a compressor, condenser and evaporator operatively interconnected: a. an expansion valve comprising a body having an inlet and an outlet interconnected by a passage for flow therethrough, the outlet being connected to a line leading to the evaporator, and the inlet being connected to the high pressure side of the system, b. a valve seat defining a valve port in the passage, c. the valve body being provided with a cylindrical chamber at one side of the valve port, d. a valve means movably mounted in the chamber for movement toward or away from the valve seat to control flow through the valve port, e. a spring means tending to urge the valve means toward a closed position, f. a flexible motor element carried by the body and operatively connected to the valve meanS for moving the valve means, g. thermal-sensing means subjecting one side of the motor element to a pressure that is a function of the temperature of the refrigerant at the evaporator outlet and tending to move the valve means to an open position, h. means subjecting the other side of the motor element to a pressure of the refrigerant at some point of the system and tending to move the valve means to the closed position, and i. the valve means including: 1. a piston movably mounted in the cylinder, 2. a first plastic seal carried by the piston and slidably yet sealably engaging the wall of the cylindrical chamber, 3. a second plastic seal carried by the piston and selectively engaging the valve seat to close the valve port, 4. opposed first and second pressure surfaces on the piston, the first pressure surface being defined by the valve port and subjected to the pressure in the valve passage at one side of the valve port, and tending to move the valve means toward the open position, and 5. means subjecting the second pressure surface to the same pressure exerted on the first pressure surface and tending to urge the valve means toward the closed position.
Claim 2
Dependent Claim
345 words
In a refrigeration system having a compressor, condenser and evaporator operatively interconnected: a. an expansion valve comprising a body having an inlet and an outlet interconnected by a passage for flow therethrough, the outlet being connected to a line leading to the evaporator, and the inlet being connected to the high pressure side of the system, b. a valve seat defining a valve port in the passage, c. the valve body being provided with a cylindrical chamber at one side of the valve port, d. a valve means movably mounted in the chamber for movement toward or away from the valve seat to control flow through the valve port, e. a spring means tending to urge the valve means toward a closed position, f. a flexible motor element carried by the body and operatively connected to the valve meanS for moving the valve means, g. thermal-sensing means subjecting one side of the motor element to a pressure that is a function of the temperature of the refrigerant at the evaporator outlet and tending to move the valve means to an open position, h. means subjecting the other side of the motor element to a pressure of the refrigerant at some point of the system and tending to move the valve means to the closed position, and i. the valve means including: 1. a piston movably mounted in the cylinder, 2. a first plastic seal carried by the piston and slidably yet sealably engaging the wall of the cylindrical chamber, 3. a second plastic seal carried by the piston and selectively engaging the valve seat to close the valve port, 4. opposed first and second pressure surfaces on the piston, the first pressure surface being defined by the valve port and subjected to the pressure in the valve passage at one side of the valve port, and tending to move the valve means toward the open position, and 5. means subjecting the second pressure surface to the same pressure exerted on the first pressure surface and tending to urge the valve means toward the closed position.
Claim 3
Dependent Claim
19 words
a first plastic seal carried by the piston and slidably yet sealably engaging the wall of the cylindrical chamber,
Claim 4
Dependent Claim
19 words
a first plastic seal carried by the piston and slidably yet sealably engaging the wall of the cylindrical chamber,
Claim 5
Dependent Claim
30 words
In a refrigeration system as defined in claim 1, in which: j. the opposed first and second pressure surfaces on the piston having areas to provide a substantially pressure-balanced piston.
Claim 6
Dependent Claim
19 words
a second plastic seal carried by the piston and selectively engaging the valve seat to close the valve port,
Claim 7
Dependent Claim
19 words
a second plastic seal carried by the piston and selectively engaging the valve seat to close the valve port,
Claim 8
Dependent Claim
78 words
In a refrigeration system as defined in claim 2, in which: k. the means subjecting the said other side of the motor element to a pressure of the refrigerant at some point of the system is an external tube communicating the said other side of the motor element with the system downstream of the valve outlet, the piston remaining pressure-balanced even if a pressure drop occurs between the valve outlet and the external tube connection to the system.
Claim 9
Dependent Claim
47 words
opposed first and second pressure surfaces on the piston, the first pressure surface being defined by the valve port and subjected to the pressure in the valve passage at one side of the valve port, and tending to move the valve means toward the open position, and
Claim 10
Dependent Claim
47 words
opposed first and second pressure surfaces on the piston, the first pressure surface being defined by the valve port and subjected to the pressure in the valve passage at one side of the valve port, and tending to move the valve means toward the open position, and
Claim 11
Dependent Claim
57 words
In a refrigeration system as defined in claim 1, in which: j. the piston includes a nose constituting at least a part of the first pressure surface, the nose extending beyond the second plastic seal and through the valve port, and k. the nose is selectively shaped and contoured to vary the nominal capacity of the valve.
Claim 12
Dependent Claim
44 words
In a refrigeration system as defined in claim 4, in which: l. the piston nose is detachably connected to the piston so that noses of different shapes and contours can be selectively attached to the piston to change the nominal capacity of the valve.
Claim 13
Dependent Claim
27 words
means subjecting the second pressure surface to the same pressure exerted on the first pressure surface and tending to urge the valve means toward the closed position.
Claim 14
Dependent Claim
27 words
means subjecting the second pressure surface to the same pressure exerted on the first pressure surface and tending to urge the valve means toward the closed position.
Claim 15
Dependent Claim
80 words
In a refrigeration system as defined in claim 4, in which: l. the piston includes adjacent first and second piston bodies, m. the first plastic seal is located against one end of the first body, n. the second plastic seal is sandwiched between the other end of the first piston body and the second piston body, and o. the nose includes a threaded shank threadedly engaging the first and second piston bodies to clamp the piston bodies and seals together.
Claim 16
Dependent Claim
33 words
In a refrigeration system as defined in claim 6, in which: p. the said means subjecting the second pressure surface to a pressure includes a hole extending through the piston nose and shank.
Claim 17
Dependent Claim
32 words
In a refrigeration system as defined in claim 6, in which: p. the piston nose engages and clamps the first plastic seal to the said one end of the first piston body.
Claim 18
Dependent Claim
73 words
In a refrigeration system as defined in claim 6, in which: p. the plastic seals are provided with holes therethrough, q. the piston bodies are provided with threaded bores therethrough axially aligned with the seal holes, and r. the threaded shank extends through the seal holes and is threadedly attached in the threaded bores to draw the piston nose against the first plastic seal and thereby clamp the piston bodies and seals together.
Claim 19
Dependent Claim
56 words
In a refrigeration system as defined in claim 6, in which: p. the plastic seal includes a down-turned peripheral flange sealably yet slidably engaging the wall of the cylindrical chamber, and q. the sEcond piston body is provided with a peripheral recess extending behind the peripheral flange of the second plastic seal for a pressure compartment.
Claim 20
Dependent Claim
145 words
In a refrigeration system as defined in claim 3, in which: j. a push rod extends through a body bore and into the valve passage to operatively interconnect the flexible motor element and the valve means for moving the valve means, k. the valve body includes a guide portion in the valve passage through which the said body bore extends, the guide portion being provided with an annular edge about the body bore and push rod and being spaced from the valve means in the valve passage, l. a seal collar of plastic material slidably yet sealably mounted with a close fit on the push rod between the guide portion and the valve means, and m. a spring means about the push rod urging the seal collar against the annular edge to seal the clearance of the bore between the push rod and guide portion.
Claim 21
Dependent Claim
54 words
In a refrigeration system as defined in claim 11, in which: n. the guide portion is countersunk about the body bore internally of the annular edge so that during normal motion of the valve means, the portion of the push rod that engages the guide portion will not rub also on the seal collar.
Claim 22
Dependent Claim
318 words
In a refrigeration system having a compressor, condenser and evaporator operatively interconnected: a. an expansion valve comprising a body having an inlet and an outlet interconnected by a passage for flow therethrough, the outlet being connected to a line leading to the evaporator, and the outlet being connected to the high pressure side of the system, b. a valve seat defining a valve port in the passage, c. a valve means movably mounted in the body for movement toward or away from the valve seat to control flow through the valve port, d. a spring means tending to urge the valve means toward a closed position, e. a flexible motor element carried by the body, f. a push rod extending through a body bore and operatively interconnecting the flexible motor element and the valve means for moving the valve means, g. a thermal-sensing means subjecting one side of the motor element to a pressure that is a function of the temperature of the refrigerant at the evaporator outlet and tending to move the valve means to an open position, h. means subjecting the other side of the motor element to a pressure of the refrigerant at some point of the system and tending to move the valve means to the closed position, i. the body including a guide portion through which the said body bore extends, the guide portion extending into the valve passage and spaced from the valve means, the guide portion being provided with an annular edge about the body bore and push rod, j. a seal collar of plastic material slidably yet sealably mounted with a close fit on the push rod between the guide portion and the valve means, and k. a spring means about the push rod urging the seal collar against the annular, substantially knife edge to seal the clearance of the body bore between the push rod and the guide portion.
Claim 23
Dependent Claim
318 words
In a refrigeration system having a compressor, condenser and evaporator operatively interconnected: a. an expansion valve comprising a body having an inlet and an outlet interconnected by a passage for flow therethrough, the outlet being connected to a line leading to the evaporator, and the outlet being connected to the high pressure side of the system, b. a valve seat defining a valve port in the passage, c. a valve means movably mounted in the body for movement toward or away from the valve seat to control flow through the valve port, d. a spring means tending to urge the valve means toward a closed position, e. a flexible motor element carried by the body, f. a push rod extending through a body bore and operatively interconnecting the flexible motor element and the valve means for moving the valve means, g. a thermal-sensing means subjecting one side of the motor element to a pressure that is a function of the temperature of the refrigerant at the evaporator outlet and tending to move the valve means to an open position, h. means subjecting the other side of the motor element to a pressure of the refrigerant at some point of the system and tending to move the valve means to the closed position, i. the body including a guide portion through which the said body bore extends, the guide portion extending into the valve passage and spaced from the valve means, the guide portion being provided with an annular edge about the body bore and push rod, j. a seal collar of plastic material slidably yet sealably mounted with a close fit on the push rod between the guide portion and the valve means, and k. a spring means about the push rod urging the seal collar against the annular, substantially knife edge to seal the clearance of the body bore between the push rod and the guide portion.
Claim 24
Dependent Claim
54 words
In a refrigeration system as defined in claim 13, in which: l. the guide portion is countersunk about the body bore internally of the annular edge so that during normal motion of the valve means, the portion of the push rod that engages the guide portion will not rub also on the seal collar.
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) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |