The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 22, 1997
Filed:
Mar. 24, 1994
Elmer C Lupton, Jr, Boston, MA (US);
Thomas E Ford, Winchester, MA (US);
Peter E Ford, North Billerica, MA (US);
Trans World Services, Melrose, MA (US);
Abstract
A low cost, disposable temperature sensor comprising a non-porous rigid substrate having a colored patch of a contrasting color, covered by a thermochromic material which obscures the colored patch. The thermochromic material, which has a color in the visual range which completely obscures the underlying colored patch, is selected to have a melting or solidus point such that when the material is exposed to a predetermined temperature, the thermochromic material permanently changes to a relatively transparent color whereby the colored patch on the substrate is rendered visible through the thermochromic material. A transparent cover or film encapsulates the thermochromic material place on the substrate. In a preferred embodiment of the invention, the substrate comprises a paperboard product, and includes printed indicia for making a permanent record. The sensor has particular utility in measuring safe cooking temperature of food,