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:
May. 23, 1995
Filed:
Oct. 25, 1993
Dean L Dahnert, Fort Atkinson, WI (US);
Spacesaver Corporation, Fort Atkinson, WI (US);
Abstract
A presence detector for detecting the presence of a heat source, including a motion detector having a predetermined field of view. The motion detector is activated by movement of a heat source a certain minimum amount within that predetermined field of view. An actuator is provided for moving the motion detector sufficient to change the position of the field of view by at least that minimum amount. The actuator includes a shape memory alloy wire. The motion detector is movably or rotatably mounted to a support. The actuator is connected at one end to the motion detector and at the other to the support. The actuator also includes a biasing or return spring for re-stretching the shape memory alloy wire back to its original length once it has contracted. A strain relief spring is also provided, having a spring rate substantially higher than that of the return spring, for relieving strain on the shape memory alloy wire in case the detector rotatable mounting seizes or otherwise is prevented from moving freely.