Patent ID: 7570543

Claim:
A pressure-sensitive switch comprising: a base member made of electrically-insulating material having first and second surfaces and having an opening formed through a central portion thereof, first and second electrodes mounted on said second surface of said base member; a flexible diaphragm formed with plural corrugations having a peripheral portion fixedly secured in a substantially fluid-tight manner to said first surface of said base member and a central portion overlying said opening formed through said base member; a post having a first end attached to said central portion of said flexible diaphragm wherein said post travels freely through said opening in said base member, said post having an electrically conductive washer fixedly mounted about it where said post extends beyond said second surface of said base member, said conductive washer electrically contacting said first and second electrodes under the bias of said flexible diaphragm acting under normal atmospheric pressure; and a cap fixedly secured in a substantially fluid-tight manner to said second surface of said base member, said cap enclosing an area over said opening through said central portion of said base member, said cap providing sufficient clearance to allow movement of said post and washer beneath said cap; the foregoing elements of said switch being arranged so that when said switch is exposed to atmospheric pressure, said washer is in contact with and electrically connects said first and second electrodes, but when said switch is exposed to a pressure substantially in excess of atmospheric pressure, said central portion of said diaphragm forces said washer away from said first and second electrodes, thereby disconnecting said first and second electrodes from each other.