Non-deflection pressure switch apparatus

Claim 1

In an electronic digital weighing scale, apparatus comprising: an electrically energized weight indicating means including means providing a plurality of distinct signals indicating in combination the magnitude of a weight applied to the scale, a piezoelectric element positioned and arranged to receive a mechanical pressure signal and to generate in response thereto a weight indicating voltage signal when a weight is initially applied to the scale, a two-state circuit means having input means coupled to said piezoelectric element and output means coupled to said indicating means, the output of said two-state circuit operable from a first state deenergizing said indicating means to a second state energizing said indicating means upon initial receipt of a weight indicating signal from said piezoelectric element, and a time delay circuit coupled to said two-state circuit and said indicating means for causing said two-state circuit to switch from said second state to said first state after a predetermined delay period, said time delay circuit being responsive to said distinct signals of said indicating means such that the delay period runs only when said distinct signals indicate that the applied weight is less than a predetermined level greater than zero.