Thermal indicator

Claim 2

In a thermal indicator for providing an indication of a heated condition for an article of food when the article is heated to a predetermined temperature, the improvement comprising: A. a tubular body having an opened end and a closed end, said body being configured for facilitating an insertion of said closed end into an article of food to be heated; and B. a volatile substance deposited within said body and having a boiling point at substantially the temperature to which the article is to be heated, whereby boiling of the substance within the body is experienced when the article is heated to said predetermined temperature.

Claim 3

A thermal indicator for providing an indication of a heated condition for an article of food, when the article is heated to a predetermined temperature comprising: A. a tubular body having an opened end and a closed end, said body being configured for facilitating an insertion thereof into an article of food to be heated; B. a volatile substance deposited within said body and having a normal boiling point at substantially the temperature to which said article is to be heated; C. a pigmented, fusible sealant substantially sealing the opened end of said body, having a melting point above room temperature and below the boiling point of said volatile substance, for confining the substance within said tubular body at room temperatures and to be expelled from said body by said volatile substance in response to a boiling thereof; and D. a collar circumscribing said body adjacent to the open end thereof for receiving thereon said sealant as it is expelled from said body, for thereby providing an indication of a heated condition for said article.

Claim 4

A thermal indicator for providing an indication of a heated condition for an article of food, when the article is heated to a predetermined temperature comprising: A. a tubular body having an opened end and a closed end, said body being configured for facilitating an insertion thereof into an article of food to be heated; B. a volatile substance deposited within said body and having a normal boiling point at substantially the temperature to which said article is to be heated; C. a pigmented, fusible sealant substantially sealing the opened end of said body, having a melting point above room temperature and below the boiling point of said volatile substance, for confining the substance within said tubular body at room temperatures and to be expelled from said body by said volatile substance in response to a boiling thereof; and D. a collar circumscribing said body adjacent to the open end thereof for receiving thereon said sealant as it is expelled from said body, for thereby providing an indication of a heated condition for said article.

Claim 5

The indicator of claim 2 wherein said volatile substance includes an aqueous solution of ethyl alcohol.

Claim 6

The indicator of claim 2 wherein the sealant is a mixture of paraffin and a selected pigment.

Claim 7

A temperature responsive indicator adapted to be inserted into a mass to be subjected to temperatures above room temperature comprising: A. a tubular body having a closed end to be inserted in said mass and an opened end to be disposed externally of the mass; B. a volatile substance deposited within said tube having a boiling point at a preselected temperature; C. a sealant closing the opened end of said tube at room temperature, having a melting point above room temperature and below the boiling point of said volatile substance, to be discharged from said body in response to a boiling of said substance when the mass is heated to said preselected temperature; and D. an external annular collar concentrically supported by said tubular body for receiving said sealant as it is discharged from said body for thereby providing an indication of the temperature of said mass when the mass is heated to said preselected temperature.

Claim 8

A temperature responsive indicator adapted to be inserted into a mass to be subjected to temperatures above room temperature comprising: A. a tubular body having a closed end to be inserted in said mass and an opened end to be disposed externally of the mass; B. a volatile substance deposited within said tube having a boiling point at a preselected temperature; C. a sealant closing the opened end of said tube at room temperature, having a melting point above room temperature and below the boiling point of said volatile substance, to be discharged from said body in response to a boiling of said substance when the mass is heated to said preselected temperature; and D. an external annular collar concentrically supported by said tubular body for receiving said sealant as it is discharged from said body for thereby providing an indication of the temperature of said mass when the mass is heated to said preselected temperature.

Claim 9

The indicator of claim 5 wherein the closed end of the tube is provided with means defining a recess forming a nucleation site, for initiating boiling of said substance when the mass is heated to the boiling point of the substance.

Claim 10

The indicator of claim 6 wherein said volatile substance is selected from a class of substances having a boiling point within a range extending between 53* and 100* C. the sealant has a melting point between 47* and 65* C.

Claim 11

The indicator of claim 7 wherein the class of substances includes water, ethanol, aqueous solution of ethanol, ethyl acetate, aqueous solution of ethyl acetate, methyl acetate and ethyl formate.

Claim 12

The indicator according to claim 8 wherein said sealant is pigmented paraffin.

Claim 13

The indicator according to claim 9 wherein said collar includes an integrally related, concentric lip.