US3673811A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control device for pressure lubricated compressors
Assignee: Robertshaw US Holding Corp
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Filing: 1970-09-15
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Granted: 1972-07-04
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Expires: 1990-09-15
Abstract
Abstract Operation of an electric motor driving a refrigerant compressor having forced oil lubrication is controlled by a solenoid operated switch, the solenoid circuit including a thermostatic switch in series with a parallel connected timer switch and oil pressure differential responsive switching means. The timer switch is operated by a relay coil energized by a timing circuit which includes voltage biased switching means having alternate output circuits, one of which includes the relay coil. The switching means is controlled by a capacitor which when charged, causes the timing switching means to change the effective flow of current from one output circuit to the other. In one form of the invention the relay coil is connected in initially energized output circuit of the switching means and is shunted to open the timer switch when the switching means is biased to change energization of the output circuits. The pressure differential responsive switch shunts the timer switch to provide a holding circuit for the solenoid after opening of the timer switch and simultaneously deenergizes the timing circuit. In another form of the invention, the relay coil is connected in the other output circuit and is not energized for a period determined by charging of the capacitor to a given voltage. In this form the pressure responsive switch does not shunt the timer switch and is effective to deenergize the timer circuit in response to normal oil pressures.
Inventors
- 👤 Jay C Adams
- 👤 Russell E Cook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:00
CPC Classifications
F; F25; F25B; F25B49/00; F25B49/02; F04; F04B; F04B39/00; F04B39/02; F04B39/0207; F04B49/00; F04B49/06; F04B49/10; F25B31/00; F25B31/002; F25B49/005
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
206 words
In a refrigerating system having a refrigerant compressor including a lubrication pump for circulating lubricant in said compressor and a motor for driving said compressor, control circuitry for said motor including a condition responsive switching means and electrically powered means including energizing circuitry controlled by said condition responsive switch and operative to energize said motor when said electrically powered means is energized, second and third switching means in said energizing circuitry, said second switching means having first and second alternate switching positions, said third switching means normally open and including electrically energized means to close said third switching means and cooperate with said condition responsive switch to complete said energizing circuit, electrically responsive timer means to deenergize said electrically energized means a period after energization of said electrically energized means, said electrically responsive timer means having an energizing circuit including said first alternative switching position of said second switching means, said second switching means being operative in its second alternative switching position to deenergize said timer means and complete a shunt circuit around said third switching means, and means responsive to lubrication oil pressure conditions in said pump and compressor for shifting said second switching means from said first alternate position to said second alternate position.
Claim 2
Dependent Claim
206 words
In a refrigerating system having a refrigerant compressor including a lubrication pump for circulating lubricant in said compressor and a motor for driving said compressor, control circuitry for said motor including a condition responsive switching means and electrically powered means including energizing circuitry controlled by said condition responsive switch and operative to energize said motor when said electrically powered means is energized, second and third switching means in said energizing circuitry, said second switching means having first and second alternate switching positions, said third switching means normally open and including electrically energized means to close said third switching means and cooperate with said condition responsive switch to complete said energizing circuit, electrically responsive timer means to deenergize said electrically energized means a period after energization of said electrically energized means, said electrically responsive timer means having an energizing circuit including said first alternative switching position of said second switching means, said second switching means being operative in its second alternative switching position to deenergize said timer means and complete a shunt circuit around said third switching means, and means responsive to lubrication oil pressure conditions in said pump and compressor for shifting said second switching means from said first alternate position to said second alternate position.
Claim 3
Dependent Claim
23 words
A refrigerating system as defined in claim 1 in which said electrically powered means and said electrically energized means each comprises a solenoid.
Claim 4
Dependent Claim
36 words
A refrigerating system as defined in claim 1 in which said timer means is automatically reset in response to interruption of its energizing circuit whereby conditions are established for initiating a time period upon reenergization thereof.
Claim 5
Dependent Claim
56 words
A refrigerating system as defined in claim 3 in which said electrically responsive timer means includes a transistor controlling energization of said electrically energized means, a biasing circuit for said transistor including a capacitor and resistor regulating the charging rate of said capacitor, and means to discharge said capacitor when said electrically responsive timer is deenergized.
Claim 6
Dependent Claim
25 words
A refrigerating system as defined in claim 3 including normally closed manually operated switching means for selectively interrupting the energizing circuit of said timer means.
Claim 7
Dependent Claim
142 words
In a refrigerating system comprising a refrigerant compressor including a lubricating system having a lubricant pump and a motor for driving said compressor, a control system for said motor including condition responsive means to initiate and terminate operation of said compressor, timer means operative to terminate operation of said compressor after a limited period following initiation of operation of said compressor means forming a cylinder, a piston movable in said cylinder, means urging said piston towards one end of said cylinder, means connecting said one end of said cylinder with the discharge of said lubricant pump, means connecting the other end of said cylinder with the intake of said pump, and means operated by movement of said piston to a predetermined position away from said one end of said cylinder for rendering said timer means ineffective to terminate operation of said compressor.
Claim 8
Dependent Claim
142 words
In a refrigerating system comprising a refrigerant compressor including a lubricating system having a lubricant pump and a motor for driving said compressor, a control system for said motor including condition responsive means to initiate and terminate operation of said compressor, timer means operative to terminate operation of said compressor after a limited period following initiation of operation of said compressor means forming a cylinder, a piston movable in said cylinder, means urging said piston towards one end of said cylinder, means connecting said one end of said cylinder with the discharge of said lubricant pump, means connecting the other end of said cylinder with the intake of said pump, and means operated by movement of said piston to a predetermined position away from said one end of said cylinder for rendering said timer means ineffective to terminate operation of said compressor.
Claim 9
Dependent Claim
121 words
In a control system for apparatus requiring maintenance of a fluid pressure differential during operation thereof, electrically powered means operative to effect anD maintain operation of said apparatus when said means is energized, an energizing circuit for said electrically powered means, switch means to control energization of said circuit, said circuit including timer means to provide an effective energizing current to said electrically powered means when said circuit is initially energized by closure of said switch means and after a period of energization to render said circuit ineffective to energize said electrically powered means, and means responsive to the presence of said fluid pressure differential for maintaining operation of said apparatus irrespective of the ineffective condition of said electrically powered means.
Claim 10
Dependent Claim
121 words
In a control system for apparatus requiring maintenance of a fluid pressure differential during operation thereof, electrically powered means operative to effect anD maintain operation of said apparatus when said means is energized, an energizing circuit for said electrically powered means, switch means to control energization of said circuit, said circuit including timer means to provide an effective energizing current to said electrically powered means when said circuit is initially energized by closure of said switch means and after a period of energization to render said circuit ineffective to energize said electrically powered means, and means responsive to the presence of said fluid pressure differential for maintaining operation of said apparatus irrespective of the ineffective condition of said electrically powered means.
Claim 11
Dependent Claim
58 words
A control system for apparatus as defined in claim 7 further characterized by said electrically powered means comprising a solenoid, said timer means comprising a field effect transistor, a transistor having its base connected with the emitter of said field effect transistor, and an RC circuit including a condenser connected with the base of said field effect transistor.
Claim 12
Dependent Claim
41 words
A control system for apparatus as defined in claim 7 further characterized by the means responsive to the pressure of said fluid differential being operative to interrupt the circuit to said timer means substantially simultaneously with maintaining operation of said apparatus.
Claim 13
Dependent Claim
198 words
In a motor driven mechanism having lubricated moving parts and including a lubrication pump for circulating lubricant, control circuitry for said motor including a condition responsive switching means and electrically powered means including energizing circuitry controlled by said condition responsive switch and operative to energize said motor when said electrically powered means is energized, second and third switching means in said energizing circuitry, said second switching means having first and second alternate switching positions, said third switching means normally open and including electrically energized means to close said third switching means and cooperate with said condition responsive switch to complete said energizing circuit electrically responsive timer means to deenergize said electrically energized means a period after energization of said electrically energized means, said electrically responsive timer means having an energizing circuit including said first alternative switching position of said second switching means, said second switching means being operative in its second alternative switching position to deenergize said timer means and complete a shunt circuit around said third switching means, and means responsive to lubrication oil pressure conditions in said pump and mechanism for shifting said second switching means from said first alternate position to said second alternate position.
Claim 14
Dependent Claim
198 words
In a motor driven mechanism having lubricated moving parts and including a lubrication pump for circulating lubricant, control circuitry for said motor including a condition responsive switching means and electrically powered means including energizing circuitry controlled by said condition responsive switch and operative to energize said motor when said electrically powered means is energized, second and third switching means in said energizing circuitry, said second switching means having first and second alternate switching positions, said third switching means normally open and including electrically energized means to close said third switching means and cooperate with said condition responsive switch to complete said energizing circuit electrically responsive timer means to deenergize said electrically energized means a period after energization of said electrically energized means, said electrically responsive timer means having an energizing circuit including said first alternative switching position of said second switching means, said second switching means being operative in its second alternative switching position to deenergize said timer means and complete a shunt circuit around said third switching means, and means responsive to lubrication oil pressure conditions in said pump and mechanism for shifting said second switching means from said first alternate position to said second alternate position.
Claim 15
Dependent Claim
24 words
A motor driven mechanism as defined in claim 10 in which said electrically powered means and said electrically energized means each comprises a solenoid.
Claim 16
Dependent Claim
223 words
In a refrigerating system having a refrigerant compressor including a lubrication pump for circulating lubricant in said compressor, and a motor for driving said compressor, control circuitry for said motor including a control switching means and electrically powered means including energizing circuitry controlled by said control switching means and operative to energize said motor when said electrically powered means is energized, second and third switching means in said energizing circuitry, said second switching means having first and second alternate switching positions, said third switching means normally open and including electrically energized means to close said third switching means to thereby cooperate with said condition responsive switch to complete said energizing circuit, electrically responsive timer means having alternative parallel circuits, one of which parallel circuits includes said electrically energized means, said timer means comprising switching means operative in response to energization of said timer means for a period to change the flow of current From one of said parallel circuits to the other parallel circuit and thereby control the energization of said electrically energized means, an energizing circuit for said electrically responsive timer means including said first alternative switching position of said second switching means, and means responsive to lubrication oil pressure conditions in said pump and compressor for shifting said second switching means from said first alternative position to said second alternative position.
Claim 17
Dependent Claim
223 words
In a refrigerating system having a refrigerant compressor including a lubrication pump for circulating lubricant in said compressor, and a motor for driving said compressor, control circuitry for said motor including a control switching means and electrically powered means including energizing circuitry controlled by said control switching means and operative to energize said motor when said electrically powered means is energized, second and third switching means in said energizing circuitry, said second switching means having first and second alternate switching positions, said third switching means normally open and including electrically energized means to close said third switching means to thereby cooperate with said condition responsive switch to complete said energizing circuit, electrically responsive timer means having alternative parallel circuits, one of which parallel circuits includes said electrically energized means, said timer means comprising switching means operative in response to energization of said timer means for a period to change the flow of current From one of said parallel circuits to the other parallel circuit and thereby control the energization of said electrically energized means, an energizing circuit for said electrically responsive timer means including said first alternative switching position of said second switching means, and means responsive to lubrication oil pressure conditions in said pump and compressor for shifting said second switching means from said first alternative position to said second alternative position.
Claim 18
Dependent Claim
38 words
A refrigerating system as defined in claim 12 further characterized by said second switching means being operative in its second alternative switching position to deenergize said timer means and complete a shunt circuit around said third switching means.
Claim 19
Dependent Claim
28 words
A refrigerating system as defined in claim 12 further characterized by said electrically energized means being connected in said other parallel circuit of said electrically energized timer means.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-04 | 1976-01-03 | 1976-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-04 | 1980-01-03 | 1980-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-04 | 1984-01-03 | 1984-07-04 | $7700.00 | Window Closed / Lapsed |