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US4488822A
Expired / Lapsed
US
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Time/temperature indicator
Assignee: Andover Monitoring Systems Corp
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Filing: 1982-01-04
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Granted: 1984-12-18
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Expires: 2002-01-04
Abstract
Abstract This invention is directed to a time/temperature indicator wherein a fluid is frozen in one compartment and subjected to the pressure of a compressible fluid through a flow control device. When the frozen fluid melts, it is forced from its compartment and the time/temperature indicator at a control rate by the compressible fluid acting through the flow controlled device.
Inventors
- 👤 Timothy A. Brennan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:27
CPC Classifications
G; G01; G01K; G01K3/00; G01K3/02; G01K3/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
66 words
A time/temperature indicator comprising: a first compartment having an input passage and a spaced-apart exit passage; a freezable fluid filling said first compartment; a second compartment having pressurizing means, a second exit passage in fluid communication with said first input passage, and a compressible fluid in said second compartment; and means for controlling the flow of compressible fluid from said second compartment to said first compartment.
Claim 2
Dependent Claim
66 words
A time/temperature indicator comprising: a first compartment having an input passage and a spaced-apart exit passage; a freezable fluid filling said first compartment; a second compartment having pressurizing means, a second exit passage in fluid communication with said first input passage, and a compressible fluid in said second compartment; and means for controlling the flow of compressible fluid from said second compartment to said first compartment.
Claim 3
Dependent Claim
24 words
A structure as set forth in claim 1 wherein there is indicia means to measure the volume of compressible fluid in said first compartment.
Claim 4
Dependent Claim
39 words
A structure as set forth in claim 1 wherein means for controlling the flow of compressible fluid from said second compartment to said first compartment is a filter intermediate of said second exit passage and said first input passage.
Claim 5
Dependent Claim
33 words
A structure as set forth in claim 1 wherein there are piston means complementing said second compartment configured to form a piston and cylinder for pressurizing said compressible fluid in said second compartment.
Claim 6
Dependent Claim
128 words
A time/temperature indicator comprising: a pressure chamber comprising a tubular wall closed at one end with an intermediate opening defined through said wall; a tubular piston for containing a freezable fluid configured to fit within said tubular wall and to move longitudinally relative to said tubular wall to compress a compressible fluid in said pressure chamber; said piston having a closed end adjacent to said closed end of the tubular wall having a passage defined through said closed end in fluid communication with said pressure chamber; control means positioned in said passage of said piston for controlling the flow of compressible fluid from said pressure chamber to the interior of said piston; and indicia means on said piston for indicating the volume of freezable fluid in said piston.
Claim 7
Dependent Claim
128 words
A time/temperature indicator comprising: a pressure chamber comprising a tubular wall closed at one end with an intermediate opening defined through said wall; a tubular piston for containing a freezable fluid configured to fit within said tubular wall and to move longitudinally relative to said tubular wall to compress a compressible fluid in said pressure chamber; said piston having a closed end adjacent to said closed end of the tubular wall having a passage defined through said closed end in fluid communication with said pressure chamber; control means positioned in said passage of said piston for controlling the flow of compressible fluid from said pressure chamber to the interior of said piston; and indicia means on said piston for indicating the volume of freezable fluid in said piston.
Claim 8
Dependent Claim
23 words
A time/temperature indicator as defined in claim 5 wherein said tubular wall and piston are cylindrical and said means is an "O" ring.
Claim 9
Dependent Claim
17 words
A time/temperature indicator as defined in claim 6 wherein the fluid flow control means is a filter.
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) | 1987-12-18 | 1988-06-18 | 1988-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-18 | 1992-06-18 | 1992-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-18 | 1996-06-18 | 1996-12-18 | $7700.00 | Window Closed / Lapsed |