US3707851A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refrigeration system efficiency monitor
Assignee: MACH ICE CO
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Filing: 1970-10-28
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Granted: 1973-01-02
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Expires: 1990-10-28
Abstract
Abstract A monitor for monitoring and comparing the efficiency of operating conditions in a refrigeration system is disclosed. The monitor includes a first and second sensing means, such as thermistors, for sensing and comparing the values of two conditions in the system, such as an ambient temperature condition and the temperature of the refrigerant in the system, where these temperatures have a known relationship. A first alarm signal or indication is provided when the difference between these temperatures exceeds a predetermined amount, and a second alarm signal or indication is provided when the differences between these temperatures is less than a predetermined amount. The monitor also includes a delay circuit for delaying the application of voltage to the mechanism until a preset period after start up of said refrigeration system, and an alarm is also given in the event electric power is lost to the refrigeration system.
Inventors
- 👤 R Mcashan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:29
CPC Classifications
F; F25; F25B; F25B49/00; F25B49/005; F25B2700/00; F25B2700/21; F25B2700/2106
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
233 words
A monitor for monitoring and comparing different operating conditions in a refrigeration system to indicate an abnormal system condition, wherein said different operating conditions in said refrigeration system differ nonlinearly as said conditions are varied between lower and upper limits comprising, in combination: first means responsive to an ambient first condition in said refrigeration system; second means responsive to a second condition in said refrigeration system having a known relationship to said ambient first condition to provide a second electrical signal having an electrical value proportional to said second condition, said first and second electrical signals having a nonlinear relationship between limits proportional to said lower and upper limits; third means responsive to said first and second means and providing a substantially constant third electrical signal when the difference between said first and second electrical signals between said limits proportioned to said lower and upper limits represents substantially normal deviations in said conditions; and fourth means for providing first indication when said third electrical signal is greater than a first predetermined value to represent such an abnormal system condition, and a second indication distinctive of said first indication when said third electrical signal is less than a second predetermined value different from said first predetermined value to also represent an abnormal system condition whereby said first and second indications are not provided in response to substantially normal deviations between said different operating conditions.
Claim 2
Dependent Claim
233 words
A monitor for monitoring and comparing different operating conditions in a refrigeration system to indicate an abnormal system condition, wherein said different operating conditions in said refrigeration system differ nonlinearly as said conditions are varied between lower and upper limits comprising, in combination: first means responsive to an ambient first condition in said refrigeration system; second means responsive to a second condition in said refrigeration system having a known relationship to said ambient first condition to provide a second electrical signal having an electrical value proportional to said second condition, said first and second electrical signals having a nonlinear relationship between limits proportional to said lower and upper limits; third means responsive to said first and second means and providing a substantially constant third electrical signal when the difference between said first and second electrical signals between said limits proportioned to said lower and upper limits represents substantially normal deviations in said conditions; and fourth means for providing first indication when said third electrical signal is greater than a first predetermined value to represent such an abnormal system condition, and a second indication distinctive of said first indication when said third electrical signal is less than a second predetermined value different from said first predetermined value to also represent an abnormal system condition whereby said first and second indications are not provided in response to substantially normal deviations between said different operating conditions.
Claim 3
Dependent Claim
14 words
The monitor of claim 1 wherein said first and second sensing means are thermistors.
Claim 4
Dependent Claim
77 words
The monitor of claim 1 wherein said last mentioned means includes means producing an electrical control voltage proportional to the difference between said first and second electrical signals, and a first indication control circuit responsive to said control voltage and providing said first indication when said control voltage exceeds a preset level, and a second indication control circuit responsive to said voltage and providing said second indication when said voltage is less than a second preset level.
Claim 5
Dependent Claim
54 words
The monitor of claim 3 further including voltage supply means providing an electrical supply voltage, and whereiN said means producing an electrical control voltage includes a voltage divider network connected to said voltage supply means, said first and second sensing means being thermistors connected to and forming a part of said voltage divider network.
Claim 6
Dependent Claim
28 words
The monitor of claim 4 wherein said voltage divider network includes means connected to one of said thermistors to vary the effective resistance thereof at different resistance levels.
Claim 7
Dependent Claim
34 words
The monitor of claim 5 wherein said last mentioned means includes a first relatively low resistance resistor connected to said one thermistor, and a second relatively high resistance resistor connected to said first resistor.
Claim 8
Dependent Claim
40 words
The monitor of claim 4 wherein said voltage supply means includes a voltage delay circuit for delaying the application of said electrical supply voltage to said voltage divider network until a preset time after said refrigeration system has been activated.
Claim 9
Dependent Claim
21 words
the monitor of claim 7 further including means for varying said delay automatically in response to outside refrigeration system temperature conditions.
Claim 10
Dependent Claim
98 words
The monitor of claim 7 further including means providing an input voltage to said delay circuit in response to the activation of said refrigeration system, and wherein said delay circuit includes a first oscillator responding to said input voltage to provide a series of pulses at a predetermined repetition rate, a second oscillator responsive to said pulses and providing an output pulse upon receipt of a predetermined number of said pulses, and switching means connected to said input voltage means and the output of said second oscillator and providing said supply voltage in responses to said output pulse.
Claim 11
Dependent Claim
34 words
The monitor of claim 9 wherein said second oscillator includes an unijunction transistor, and further including means connected between said first and second oscillators for reducing the peak point firing current of said unijunction.
Claim 12
Dependent Claim
22 words
The monitor of claim 9 further including voltage regulating means connected to said switching means to provide a substantially constant supply voltage.
Claim 13
Dependent Claim
48 words
The monitor of claim 9 further including a thermistor connected between said input voltage means and said first oscillator, said thermistor adapted to be exposed to outside refrigeration system temperature conditions to automatically vary said repetition rate in response to variations in said outside refrigeration system temperature conditions.
Claim 14
Dependent Claim
30 words
The monitor of claim 1 further including delay means for automatically applying a supply voltage to said first and second means a predetermined time after activation of said refrigeration system.
Claim 15
Dependent Claim
47 words
The mechanism of claim 13 further including a thermistor connected between said input voltage means and said first oscillator, said thermistor adapted to be exposed to outside refrigeration system temperature conditions to automatically vary said repetition rate in response to variations in said outside refrigeration system temperatures.
Claim 16
Dependent Claim
28 words
The monitor of claim 1 wherein said first and second means are resistors the resistance of which varies in response to changes in said first and second conditions.
Claim 17
Dependent Claim
23 words
The monitor of claim 15 wherein said first and second conditions are temperatures and each of said resistors has a negative temperature coefficient.
Claim 18
Dependent Claim
19 words
The monitor of claim 1 wherein said first and second means are disposed exteriorly of said closed refrigerant system.
Claim 19
Dependent Claim
218 words
A monitor for monitoring and comparing different operating conditions in a refrigeration system to indicate an abnormal system condition, wherein said refrigeration system includes a heat exchanger between a first relatively cool cooling medium and a second relatively warm cooling medium to cool said second medium, while warming said first medium, comprising, in combination: first means responsive to the temperature of said first medium to provide a first electrical signal having an electrical value proportional to said temperature of said first medium; secoNd means responsive to the temperature of said second medium in said refrigeration system to provide a second electrical signal having an electrical value proportional to said temperature of said second medium; and third means responsive to said first and second means and providing a first indication when the difference between the electrical values of said first and second electrical signals and between the temperatures of said first and second mediums, is greater than a first predetermined value to represent such an abnormal system condition, and second indication distinctive of said first indication when said difference is less than a second predetermined value different from said first predetermined value to also represent an abnormal system condition, whereby said first and second indications are not provided in response to substantially normal deviations between said different operating conditions.
Claim 20
Dependent Claim
218 words
A monitor for monitoring and comparing different operating conditions in a refrigeration system to indicate an abnormal system condition, wherein said refrigeration system includes a heat exchanger between a first relatively cool cooling medium and a second relatively warm cooling medium to cool said second medium, while warming said first medium, comprising, in combination: first means responsive to the temperature of said first medium to provide a first electrical signal having an electrical value proportional to said temperature of said first medium; secoNd means responsive to the temperature of said second medium in said refrigeration system to provide a second electrical signal having an electrical value proportional to said temperature of said second medium; and third means responsive to said first and second means and providing a first indication when the difference between the electrical values of said first and second electrical signals and between the temperatures of said first and second mediums, is greater than a first predetermined value to represent such an abnormal system condition, and second indication distinctive of said first indication when said difference is less than a second predetermined value different from said first predetermined value to also represent an abnormal system condition, whereby said first and second indications are not provided in response to substantially normal deviations between said different operating conditions.
Claim 21
Dependent Claim
44 words
the monitor of claim 18 wherein said heat exchanger is a condenser and said first cooling medium is air passed over said condenser, and said second medium is a liquid-gaseous coolant passing through said condenser and changing from a gaseous state at the inlet.
Claim 22
Dependent Claim
221 words
A monitor for monitoring and comparing different operating conditions in a refrigeration system to indicate an abnormal system condition, comprising, in combination: first means responsive to an ambient first condition in said system to provide a first electrical signal having an electrical value proportional to said ambient first condition in said refrigeration system; second means responsive to a second condition in said refrigeration system having a known relationship to said ambient first condition to provide a second electrical signal having an electrical value proportional to said second condition; and third means responsive to said first and second means and providing a first indication when the difference between the electrical values of said first and second electrical signals is greater than a first predetermined value to represent such an abnormal system condition, and a second indication distinctive of said first indication when said difference is less than a second predetermined value different from said first predetermined value to also represent an abnormal system condition whereby said first and second indications are not provided in response to substantially normal deviations between said different operating conditions; delay means for automatically applying a supply voltage to said first and second means a predetermined time after activation of said refrigeration system; and means for varying said delay automatically in response to outside refrigeration system temperature conditions.
Claim 23
Dependent Claim
221 words
A monitor for monitoring and comparing different operating conditions in a refrigeration system to indicate an abnormal system condition, comprising, in combination: first means responsive to an ambient first condition in said system to provide a first electrical signal having an electrical value proportional to said ambient first condition in said refrigeration system; second means responsive to a second condition in said refrigeration system having a known relationship to said ambient first condition to provide a second electrical signal having an electrical value proportional to said second condition; and third means responsive to said first and second means and providing a first indication when the difference between the electrical values of said first and second electrical signals is greater than a first predetermined value to represent such an abnormal system condition, and a second indication distinctive of said first indication when said difference is less than a second predetermined value different from said first predetermined value to also represent an abnormal system condition whereby said first and second indications are not provided in response to substantially normal deviations between said different operating conditions; delay means for automatically applying a supply voltage to said first and second means a predetermined time after activation of said refrigeration system; and means for varying said delay automatically in response to outside refrigeration system temperature conditions.
Claim 24
Dependent Claim
100 words
The monitor of claim 20 wherein said delay means is a delay circuit including means providing an input voltage to said circuit in response to the activation of said refrigeration system, a first oscillator responding to said input voltage to provide a series of pulses at a predetermined repetition rate, a second oscillator responsive to said pulses and providing an output signal upon receipt of a predetermined number of said pulses, and switching means connected to said input voltage means and the output of said second oscillator and switching to provide said supply voltage in response to said output signal.
Claim 25
Dependent Claim
34 words
The monitor of claim 21 wherein said second oscillator includes a unijunction transistor and further including means connected between said first and second oscillators for reducing the peak point firing current of said unijunction.
Claim 26
Dependent Claim
225 words
A monitor for monitoring and comparing different operating conditions in a refrigeration system to indicate an abnormal system condition, said refrigeration system being connected to a source of electrical power,comprising, in combination: first means responsive to an ambient first condition in said system to provide a first electrical signal having an electrical value proportional to said ambient first condition in said refrigeration system; second means Responsive to a second condition in said refrigeration system having a known relationship to said ambient first condition to provide a second electrical signal having an electrical value proportional to said second condition; and third means responsive to said first and second means and providing a first indication when the difference between the electrical values of said first and second electrical signals is greater than a first predetermined value to represent such an abnormal system condition, and second indication distinctive of said first indication when said difference is less than a second predetermined value different from said first predetermined value to also represent an abnormal system condition whereby said first and second indications are not provided in response to substantially normal deviations between said different operating conditions; and means connected to said source of electrical power and said third means and responding to the interruption of said power to said refrigeration system to alternatively provide said first and second indications.
Claim 27
Dependent Claim
225 words
A monitor for monitoring and comparing different operating conditions in a refrigeration system to indicate an abnormal system condition, said refrigeration system being connected to a source of electrical power,comprising, in combination: first means responsive to an ambient first condition in said system to provide a first electrical signal having an electrical value proportional to said ambient first condition in said refrigeration system; second means Responsive to a second condition in said refrigeration system having a known relationship to said ambient first condition to provide a second electrical signal having an electrical value proportional to said second condition; and third means responsive to said first and second means and providing a first indication when the difference between the electrical values of said first and second electrical signals is greater than a first predetermined value to represent such an abnormal system condition, and second indication distinctive of said first indication when said difference is less than a second predetermined value different from said first predetermined value to also represent an abnormal system condition whereby said first and second indications are not provided in response to substantially normal deviations between said different operating conditions; and means connected to said source of electrical power and said third means and responding to the interruption of said power to said refrigeration system to alternatively provide said first and second indications.
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) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |