US3686892A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compressor protector responsive to low refergerant charge
Assignee: Motors Liquidation Co
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Filing: 1971-05-05
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Granted: 1972-08-29
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Expires: 1991-05-05
Abstract
Abstract A compressor protector system for an air conditioning system having a compressor driven by an automobile engine through an electromagnetic clutch. When the refrigerant charge level falls below a level necessary for compressor cooling and lubrication, a thermally responsive fuse in the clutch energization circuit is made to open by a resistance wire heater. The wire heater is energized by the closing of a superheat switch responsive to the refrigerant temperature in the compressor inlet.
Inventors
- 👤 Arthur T Bassett Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:40
CPC Classifications
B; B60; B60H; B60H1/00; B60H1/00642; B60H1/00978; F; F25; F25B; F25B49/00; F25B49/005; F25B2500/00; F25B2500/22; F25B2500/222
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
184 words
In an automobile having an air conditioning system including a refrigerant compressor and an engine, a compressor protector comprising: an electromagnetic clutch for interconnecting said engine and said compressor for rotation together when said clutch is electrically energized; circuit means including a power source and a fuse for electrically energizing said clutch; said fuse having a fusible pellet which maintains a closed circuit through said fuse for energizing said clutch; spring means in said fuse for opening said closed circuit when said fusible pellet is melted by being heated; an electric resistance heater in heat transfer relation to said fusible pellet for selectively applying thermal energy to said pellet; a temperature responsive switch in heat transfer relation to refrigerant entering said compressor and in electrical connection with said resistance heater and said power source for energizing said resistance heater whenever the refrigerant temperature exceeds a predetermined value whereby after a delay during which said fusible pellet is heated and finally melted, said fuse is opened to disconnect said electromagnetic clutch from said power source and render said compressor inactive until said fuse is replaced.
Claim 2
Dependent Claim
184 words
In an automobile having an air conditioning system including a refrigerant compressor and an engine, a compressor protector comprising: an electromagnetic clutch for interconnecting said engine and said compressor for rotation together when said clutch is electrically energized; circuit means including a power source and a fuse for electrically energizing said clutch; said fuse having a fusible pellet which maintains a closed circuit through said fuse for energizing said clutch; spring means in said fuse for opening said closed circuit when said fusible pellet is melted by being heated; an electric resistance heater in heat transfer relation to said fusible pellet for selectively applying thermal energy to said pellet; a temperature responsive switch in heat transfer relation to refrigerant entering said compressor and in electrical connection with said resistance heater and said power source for energizing said resistance heater whenever the refrigerant temperature exceeds a predetermined value whereby after a delay during which said fusible pellet is heated and finally melted, said fuse is opened to disconnect said electromagnetic clutch from said power source and render said compressor inactive until said fuse is replaced.
Claim 3
Dependent Claim
243 words
In an automobile having an air conditioning system including a refrigerant compressor and an engine, a compressor protector comprising: an electromagnetic clutch for interconnecting said engine and said compressor for rotation together when said clutch is electrically energized; circuit means including a power source and a fuse for electrically energizing said clutch; said fuse having a thin walled housing enclosing an elongated space; a reciprocal piston in said housing; a first spring and a fusible pellet on one side of said piston and a second spring on the other side of said piston; a conductor insulated from said housing and extending into said elongated space into contact with said piston and thereby completing a circuit from said housing through said piston to said conductor; an electric resistance heater in heat transfer relation to said housing and said fusible pellet for selectively applying thermal energy to said pellet; a temperature responsive switch in heat transfer relation to refrigerant entering said compressor and in electrical connection with said resistance heater and said power source for energizing said resistance heater whenever the refrigerant temperature exceeds a predetermined value and whereby after a delay during which said fusible pellet is heated and finally melted, said first spring relaxes by extension into the now liquefied pellet and said second spring moves said piston out of contact with said conductor to disconnect said electromagnetic clutch from said power source and render said compressor inactive until said fuse is replaced.
Claim 4
Dependent Claim
243 words
In an automobile having an air conditioning system including a refrigerant compressor and an engine, a compressor protector comprising: an electromagnetic clutch for interconnecting said engine and said compressor for rotation together when said clutch is electrically energized; circuit means including a power source and a fuse for electrically energizing said clutch; said fuse having a thin walled housing enclosing an elongated space; a reciprocal piston in said housing; a first spring and a fusible pellet on one side of said piston and a second spring on the other side of said piston; a conductor insulated from said housing and extending into said elongated space into contact with said piston and thereby completing a circuit from said housing through said piston to said conductor; an electric resistance heater in heat transfer relation to said housing and said fusible pellet for selectively applying thermal energy to said pellet; a temperature responsive switch in heat transfer relation to refrigerant entering said compressor and in electrical connection with said resistance heater and said power source for energizing said resistance heater whenever the refrigerant temperature exceeds a predetermined value and whereby after a delay during which said fusible pellet is heated and finally melted, said first spring relaxes by extension into the now liquefied pellet and said second spring moves said piston out of contact with said conductor to disconnect said electromagnetic clutch from said power source and render said compressor inactive until said fuse is replaced.
Claim 5
Dependent Claim
278 words
In an automobile having an air conditioning system including a refrigerant compressor and an engine, a compressor protector comprising: an electromagnetic clutch for interconnecting said engine and said compressor for rotation together when said clutch is electrically energized; circuit means including a power source and a fuse for electrically energizing said clutch; said fuse having a thin walled housing enclosing an elongated space; a reciprocal piston in said housing; a first spring and a fusible pellet on one side of said piston and a second spring on the other side of said piston; a conductor insulated from said housing and extending into said elongated space into contact with said piston and thereby completing a circuit from said housing through said piston to said conductor; an electric resistance heater in heat transfer relation to said housing and said fusible pellet for selectively applying thermal energy tO said pellet; a temperature responsive switch in heat transfer relation to refrigerant entering said compressor and in electrical connection with said resistance heater and said power source for selectively energizing said resistance heater; said switch including a refrigerant filled expandable bellows portion of conductive material which expands with increases in refrigerant temperature in the inlet of the compressor to contact a conductor and energize said resistance heater whenever the refrigerant temperature exceeds a predetermined value and whereby after a delay during which said fusible pellet is heated and finally melted, said first spring relaxes by extension into the now liquified pellet and said second spring moves said piston out of contact with said conductor to disconnect said electromagnetic clutch from said power source and render said compressor inactive until said fuse is replaced.
Claim 6
Dependent Claim
278 words
In an automobile having an air conditioning system including a refrigerant compressor and an engine, a compressor protector comprising: an electromagnetic clutch for interconnecting said engine and said compressor for rotation together when said clutch is electrically energized; circuit means including a power source and a fuse for electrically energizing said clutch; said fuse having a thin walled housing enclosing an elongated space; a reciprocal piston in said housing; a first spring and a fusible pellet on one side of said piston and a second spring on the other side of said piston; a conductor insulated from said housing and extending into said elongated space into contact with said piston and thereby completing a circuit from said housing through said piston to said conductor; an electric resistance heater in heat transfer relation to said housing and said fusible pellet for selectively applying thermal energy tO said pellet; a temperature responsive switch in heat transfer relation to refrigerant entering said compressor and in electrical connection with said resistance heater and said power source for selectively energizing said resistance heater; said switch including a refrigerant filled expandable bellows portion of conductive material which expands with increases in refrigerant temperature in the inlet of the compressor to contact a conductor and energize said resistance heater whenever the refrigerant temperature exceeds a predetermined value and whereby after a delay during which said fusible pellet is heated and finally melted, said first spring relaxes by extension into the now liquified pellet and said second spring moves said piston out of contact with said conductor to disconnect said electromagnetic clutch from said power source and render said compressor inactive until said fuse is replaced.
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) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |