US4028688A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refrigeration unit air temperature detection alarm system
Assignee: Individual
•
Filing: 1975-10-10
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Granted: 1977-06-07
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Expires: 1995-10-10
Abstract
Abstract A compact alarm system is provided by a temperature sensing switch within a refrigeration unit, the temperature of which actuates the switch when temperature rises to a predetermined level. Change of condition of the contacts induces a pulse which triggers an integrated circuit timer. The timer imposes a predetermined delay before activating a communications linkage. No permanent wiring and, at most, only light wiring is required in the location of the refrigeration unit and wiring may be eliminated entirely by employing individual transmitters in each case. Remote alarm means provides a predetermined alarm indicating abnormal conditions in the refrigeration unit, preferably in response to a radio signal transmitted from the location proximate to the refrigeration unit. The receiver activates an automatic telephone dialer which dials pre-programmed telephone number and plays a pre-recorded message.
Inventors
- 👤 Joel B. Goleman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:03
CPC Classifications
H; H04; H04M; H04M11/00; H04M11/04; H04M11/045; F; F25; F25D; F25D29/00; F25D29/008
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
188 words
An alarm system for a refrigeration unit whose enclosure contains an energy permeable portion, which may be an opening, comprising a temperature sensing means within the refrigeration unit including a switch device effectively employing a change of state of contacts, opening or closing, for directly sensing air temperature in the refrigeration unit and producing an indication when air temperature reaches or exceeds a predetermined level, an integrated circuit timer means containing its own power source independent of a general power source required to operate said refrigeration unit, and directly actuated by the contacts of said temperature sensing means when the air temperature in the refrigeration unit reaches or exceeds the predetermined level and terminated and reset when the temperature drops below the predetermined level, a communication link means employing energy to which said enclosure portion is permeable responsive to said timer means transmitting an actuating signal to initiate the remote alarm means after the timer means has been actuated continuously for a set predetermined time, and remote alarm means responsive to said communication linkage means providing a predetermined alarm indicating an abnormal temperature condition in the refrigeration unit.
Claim 2
Dependent Claim
188 words
An alarm system for a refrigeration unit whose enclosure contains an energy permeable portion, which may be an opening, comprising a temperature sensing means within the refrigeration unit including a switch device effectively employing a change of state of contacts, opening or closing, for directly sensing air temperature in the refrigeration unit and producing an indication when air temperature reaches or exceeds a predetermined level, an integrated circuit timer means containing its own power source independent of a general power source required to operate said refrigeration unit, and directly actuated by the contacts of said temperature sensing means when the air temperature in the refrigeration unit reaches or exceeds the predetermined level and terminated and reset when the temperature drops below the predetermined level, a communication link means employing energy to which said enclosure portion is permeable responsive to said timer means transmitting an actuating signal to initiate the remote alarm means after the timer means has been actuated continuously for a set predetermined time, and remote alarm means responsive to said communication linkage means providing a predetermined alarm indicating an abnormal temperature condition in the refrigeration unit.
Claim 3
Dependent Claim
73 words
The alarm system of claim 1 in which the temperature sensing means is a thermometer having a bore and a bulb having good heat exchange characteristics containing an electrically conductive fluid expandable in response to temperature increases, with at least a pair of conductive leads extending into said bore such that at a predetermined temperature level said electrically conductive fluid completes a circuit between said leads and actuates the integrated circuit timer means.
Claim 4
Dependent Claim
49 words
The alarm system of claim 1 in which the system employs as the communication linkage means a radio transmitter portion and a receiver portion, with said transmitter portion actuated by said actuating signal and sending a signal to said receiver portion which in response activates said remote alarm means.
Claim 5
Dependent Claim
26 words
The alarm system of claim 3 in which the transmitter portion is an RF transmitter suitable for location within or immediately adjacent to the refrigeration unit.
Claim 6
Dependent Claim
24 words
The alarm system of claim 4 in which the receiver portion is responsive to different signals from different transmitters for actuating different alarm responses.
Claim 7
Dependent Claim
26 words
The alarm system of claim 1 in which the communication linkage means includes an automatic dialing means for dialing a preprogrammed number representing said remote location.
Claim 8
Dependent Claim
67 words
The alarm means of claim 1 in which said timer means responds to said changed state of said switch when said predetermined air temperature level is reached or exceeded and terminated and reset when the temperature falls below the predetermined level and providing an activating signal to initiate the remote alarm means only after the timer has been activated continuously for a set predetermined period of time.
References Cited (Backward Citations)
US2741099A
Cited
US2923786A
Cited
US3028586A
Cited
US3148363A
Cited
US3196286A
Cited
US3852740A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-06 | 1980-12-06 | 1981-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-06 | 1984-12-06 | 1985-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-06 | 1988-12-06 | 1989-06-07 | $7700.00 | Window Closed / Lapsed |