摘要 |
A pressure switch for use in a device for alarming the reduction of pneumatic pressure of vehicle tire is disclosed. The switch comprises a base board, a bellofram secured to the base board and having conductive coating of one electric contact applied to the inner surface and the outer surface thereof and having both bellows and diaphragm characteristics, a housing provided to enclose the bellofram and for defining a hermetic chamber, and a conductor provided at inner portion and outer portion of the bellofram near the center of the diaphragm portion thereof and for forming another electric contact. A back pressure is applied to the inner portion or outer portion of the bellofram against the pneumatic pressure of a vehicle tire.
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