Patent ID: 6466140
Filing Date: 2002-10-15
Classification: H01H,H03K

Abstract:
A pedestrian push button assembly for activating signal generating means to generate a signal at a street crosswalk, said pedestrian push button assembly comprising:a rigid frame (13) having opposing inner (14) and outer (15) frame ends, said outer frame end (15) having a central aperture (16), a stopper surface (17) located ulterior to said central aperture (16), and a parametric groove (19) surrounding said central aperture (16); a resiliently-biasing sealing element (21) adapted to be seated in said parametric groove; a piezoelectric element (22, 23, 24) positioned across said central aperture and electrically connected to said signal generating means by electrical conduit means, wherein said piezoelectric element activates said signal generating means to generate said signal when mechanical pressure is acted thereupon; and a button portion (27) having opposing inner (29) and outer (28) button ends, said inner button end (29) having a resiliently-biasing pressure element (31) mounted thereon, an abutment surface (34) located ulterior to said resiliently-biasing pressure element (31), and a seal contact portion (35) surrounding said resiliently-biasing pressure element (31), said inner button end (29) adapted to be secured to said outer frame end (15) wherein said seal contact portion (35) sealably contacts said resiliently-biasing sealing element (21) in an unbiased state, said abutment surface (34) confronts said stopper surface (17), and said resiliently-biasing pressure element (31) contacts said piezoelectric element, and said stopper surface (17) contacts said abutment surface (34) to stop any further pressure on said resiliently-biasing pressure element (31) and on said piezoelectric element (22); whereby, upon a pressure being applied against said outer button end, said seal contact portion resiliently-biases said resiliently-biasing sealing element, and said resiliently-biasing pressure element is urged to apply a mechanical pressure against said piezoelectric element, thereby activating said signal generating means to generate said signal and whereby the amount of pressure which can be exerted on the piezoelectric element (22) is limited by the stopping of the button portion (27) by contact between its abutment surface (34) and said stopper surface (17).