Patent ID: 6945693

Claim:
A cooking thermometer having an audible alarm, comprising: a generally cylindrical housing assembly and a substantially hollow skewer extending coaxially therefrom, said skewer having a proximal end contiguous to said housing assembly and a sharpened distal end; said housing assembly further including a temperature indicia plate, a pivoting pointer movable over said indicia plate; a set temperature needle selectably manually positionable over said indicia plate, and a tension wound spring-type audible alarm mechanism activated by alignment of said set temperature needle and said pointer, a linear segment of heat contractible shape memory alloy wire disposed within said skewer and having a first end and a second end wherein said first end is fastened to said distal end of said skewer, said shape memory alloy wire being selected such that said wire begins phase transformation at a first lower temperature M S and completes phase transformation at a second higher temperature A F; a connecting rod disposed within said skewer and secured to said second end of said shape memory alloy wire; said connecting rod having an upper end extending into said cylindrical housing assembly; a cam assembly operatively associated with said connecting rod wherein vertical movement of said connecting rod is translated into rotational motion and transmitted to said pointer through a gear assembly; and a spring biasing means constructed and arranged to exert stress on said shape memory alloy wire during phase transformation, said spring biasing means having parameters which are configured to impart desired phase transformation characteristics to said shape memory alloy; whereby optimization of said phase transformation and linearity of temperature response are obtained.