US4038873A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature monitor and indicator
Assignee: Tempil Corp
•
Filing: 1975-06-18
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Granted: 1977-08-02
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Expires: 1995-06-18
Abstract
Abstract A time/temperature device for monitoring and indicating variations in the ambient temperature of a space being monitored above a predetermined temperature level is encapsulated in a plastic bag, and uses a carrier to be impregnated with a fusible diffusing medium having a sharp melting point at the predetermined temperature being monitored adapted above the melting point to change from the solid phase to substantially the molten or liquid phase and vice versa below the melting point, a dye composition is formed into a mixture in a given concentration so that it can be coated at one end of the carrier, and the concentration will be in ratio to the volume of the diffusing medium so that the dye composition has a finite and reproducible diffusion rate through the diffusing medium whenever the diffusing medium is in the liquid state and exhibits no diffusion when the diffusing medium is in the solid state, and an indicating section on the face of the carrier for the time/temperature device will provide a visible measurement of the time period of days or weeks over which diffusion of the dye occurs.
Inventors
- 👤 Elias Kimmel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:27
CPC Classifications
G; G01; G01K; G01K11/00; G01K11/06; G01K3/00; G01K3/02; G01K3/04
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
45 words
A time/temperature indicator for providing a time history of a monitored space above a predetermined temperature comprising: a. carrier means formed from a sheet of porous material having, longitudinally extending indicating means thereon, b. a dye composition coated on the carrier adjacent said indicating means,
Claim 2
Dependent Claim
45 words
A time/temperature indicator for providing a time history of a monitored space above a predetermined temperature comprising: a. carrier means formed from a sheet of porous material having, longitudinally extending indicating means thereon, b. a dye composition coated on the carrier adjacent said indicating means,
Claim 3
Dependent Claim
136 words
c. a diffusing medium having a sharp melting point at the predetermined monitoring temperature, d. holder means connected to said carrier means for maintaining the diffusing medium inactive and disposed to substantially full impregnate the carrier means initially with diffusing medium when the holder means is activated for use, e. said dye composition to diffuse through said diffusing medium as a function of the rate of transfer of said dye composition in the diffusing medium whenever the diffusing medium is above its melting point to provide progressive coloration along said indicating means on the carrier means as an irreversible record of the time said time/temperature indicator is exposed to temperature in excess of said predetermined monitored temperature, and f. clear envelope means disposed to surround and seal the carrier means and holder means in assembled relation.
Claim 4
Dependent Claim
136 words
c. a diffusing medium having a sharp melting point at the predetermined monitoring temperature, d. holder means connected to said carrier means for maintaining the diffusing medium inactive and disposed to substantially full impregnate the carrier means initially with diffusing medium when the holder means is activated for use, e. said dye composition to diffuse through said diffusing medium as a function of the rate of transfer of said dye composition in the diffusing medium whenever the diffusing medium is above its melting point to provide progressive coloration along said indicating means on the carrier means as an irreversible record of the time said time/temperature indicator is exposed to temperature in excess of said predetermined monitored temperature, and f. clear envelope means disposed to surround and seal the carrier means and holder means in assembled relation.
Claim 5
Dependent Claim
40 words
A time/temperature indicator as claimed in claim 1, wherein said holder means comprises, a frangible container for holding said diffusing medium, and a porous sleeve element disposed about said frangible container for retaining said diffusing medium in said carrier means.
Claim 6
Dependent Claim
59 words
A time/temperature indicator as claimed in claim 1, wherein said indicating means comprises a calibrated scale drawn upon the visible surface of said carrier, said scale in spaced relationship to said dye composition whereby a unit time marking of said scale provides a substantially accurate representation of the rate of diffusion of said dye composition through said diffusing medium.
Claim 7
Dependent Claim
34 words
A time/temperature indicator as claimed in claim 1 wherein said diffusing medium is a single isomer of an organic compound with a sharp melting point in the range of about -18° to 28° C.
Claim 8
Dependent Claim
33 words
A time/temperature indicator as claimed in claim 4, wherein said diffusing medium is a normal hydrocarbon selected from the group consisting of n-tetradecane, n-pentadecane, n-hexadecane, n-heptadecane, n-octadecane, n-tetradecene-1, n-pentadecene-1, n-hexadecene-1, n-heptadecene-1, and n-octadecene-1.
Claim 9
Dependent Claim
53 words
A time/temperature indicator as claimed in claim 1 wherein the ratio of the weight of the diffusing medium to the weight of the carrier means is selected so that the diffusing medium will saturate the carrier means and will not form a body of liquid above the melting point of the diffusing medium.
Claim 10
Dependent Claim
30 words
A time/temperature indicator as claimed in claim 1 wherein the weight of the diffusing medium to the weight of the carrier means is in a ratio of 1 to 2.
Claim 11
Dependent Claim
39 words
A time/temperature indicator as claimed in claim 1 wherein the ratio of the weight of the diffusing medium to the weight of the carrier means does not exceed 1 to 1 and is not less than 1 to 5.
Claim 12
Dependent Claim
41 words
A time/temperature indicator as claimed in claim 1 wherein the dye composition is selected from the group consisting of a diazo dye with a color index solvent red No. 26, and a diazo dye with color index solvent red No. 258.
Claim 13
Dependent Claim
30 words
A time/temperature indicator as claimed in claim 1 wherein the dye composition is selected from the group consisting of an anthraquinone dye with a color index solvent blue No. 16.
Claim 14
Dependent Claim
48 words
A time/temperature indicator as claimed in claim 1 having an activation window disposed a spaced distance from the indicating means, and a rapidly diffusing dye composition coated on said carrier means adjacent the activation window to color said activation window for signalling proper activation of said time/temperature indicator.
Claim 15
Dependent Claim
146 words
A time/temperature indicator for use with a frozen food package comprising: a. carrier means made of porous material and having longitudinally extending indicating means thereon, b. a diffusing medium substantially fully impregnating said carrier means initially, said diffusing medium having a sharp melting point at a predetermined temperature and changing from a solid state to a liquid state whenever said predetermined temperature is exceeded, c. a dye composition coating a portion of the surface of said carrier means adjacent said indicating means, said dye composition diffusable at a controlled rate through said diffusing medium whenever said diffusing medium is in a liquid state to provide progressive coloration along said indicating means on the carrier means as an irreversible record of the time said time/temperature indicator is exposed to a temperature in excess of said predetermined temperature at which the diffusing medium is in a liquid state.
Claim 16
Dependent Claim
146 words
A time/temperature indicator for use with a frozen food package comprising: a. carrier means made of porous material and having longitudinally extending indicating means thereon, b. a diffusing medium substantially fully impregnating said carrier means initially, said diffusing medium having a sharp melting point at a predetermined temperature and changing from a solid state to a liquid state whenever said predetermined temperature is exceeded, c. a dye composition coating a portion of the surface of said carrier means adjacent said indicating means, said dye composition diffusable at a controlled rate through said diffusing medium whenever said diffusing medium is in a liquid state to provide progressive coloration along said indicating means on the carrier means as an irreversible record of the time said time/temperature indicator is exposed to a temperature in excess of said predetermined temperature at which the diffusing medium is in a liquid state.
Claim 17
Dependent Claim
40 words
A time/temperature indicator for use with a frozen food package as claimed in claim 12 wherein said diffusing medium is stored in a rupturable vessel adjacent said carrier means and the time/temperature indicator is activated by rupture of said vessel.
Claim 18
Dependent Claim
36 words
A time/temperature indicator for use with a frozen food package as claimed in claim 13, wherein said diffusing medium is present in a quantity which when in a liquid state is absorbed by said carrier means.
Claim 19
Dependent Claim
34 words
A time/temperature indicator as claimed in claim 12 wherein said diffusing medium is a single isomer of an organic compound with a sharp melting point in the range of about -8° to 28° F.
Claim 20
Dependent Claim
33 words
A time/temperature indicator as claimed in claim 15 wherein said organic compound is a normal hydrocarbon selected from the group consisting of n-tetradecane, n-pentadecane, n-hexadecane, n-heptadecane, n-octadecane, n-tetradecene-1, n-pentadecene-1, n-hexadecene-1, n-heptadecene-1, and n-octadecene-1.
Claim 21
Dependent Claim
41 words
A time/temperature indicator as claimed in claim 12 wherein the dye composition is selected from the group consisting of a diazo dye with a color index solvent red No 26, and a diazo dye with color index solvent red No. 258.
Claim 22
Dependent Claim
30 words
A time/temperature indicator as claimed in claim 12 wherein the dye composition is selected from the group consisting of an anthraquinone dye with a color index solvent blue No. 16.
Claim 23
Dependent Claim
78 words
A time/temperature indicator as claimed in claim 12 wherein said diffusing medium is a single isomer of an organic compound with a sharp melting point in a range of about -18° to 28° C., and the dye composition is selected from the group consisting of a diazo dye with a color index solvent red No. 26; a diazo dye with a color index solvent red No. 258, and anthraquinone dyes with a color index solvent blue No. 16.
Claim 24
Dependent Claim
48 words
A time/temperature indicator as claimed in claim 12 having an activation window disposed a spaced distance from the indicating means, and a rapidly diffusing dye composition coated on said carrier means adjacent the activation window to color said activation window for signalling proper activation of said time/temperature indicator.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-01 | 1981-01-31 | 1981-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-01 | 1985-01-31 | 1985-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-01 | 1989-01-31 | 1989-08-02 | $7700.00 | Window Closed / Lapsed |