×

Piezoelectric electronic switch

  • US 5,231,326 A
  • Filed: 01/30/1992
  • Issued: 07/27/1993
  • Est. Priority Date: 01/30/1992
  • Status: Expired due to Term
First Claim
Patent Images

1. In a push button switch of the type comprising a piezoelectric element having opposite faces with one face bonded to a flexible support pate to form a laminate, electrodes coupled with the opposite faces of said piezoelectric element, an electronic switching circuit responsive to a predetermined voltage having a first polarity to switch its conductive state, a push button for flexing said laminate and thereby generating a voltage between said electrodes having said first polarity and having a magnitude at least as great as that of said predetermined voltage, said electrodes being electrically coupled with said circuit for switching its conductive state when said laminate is flexed by said push button, said support plate and said piezoelectric element having different temperature coefficients of expansion whereby said laminate is flexed by a predetermined rate of temperature increase to generate a voltage between said electrodes having a magnitude at least as great as that of said predetermined voltage, the improvement comprising:

  • said push button being coupled with said laminate for flexing it in a direction opposite the direction the laminate is flexed due to increasing temperature, whereby the voltage produced by flexion of the laminate due to increasing temperature has a polarity opposite that of said first polarity.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×