Patent ID: 7381916

Claim:
A rolling-ball switch, comprising: a casing comprising an annulus chamber for guiding rail, the annulus chamber comprising two dents on two end faces thereof, and the casing comprising two racks opposite to each other; a first terminal arranged on the casing and comprising a first contact plate extended into one end face of the annulus chamber; a second terminal arranged on the casing and comprising a second contact plate extended into one end face of the annulus chamber; a common terminal arranged on the casing and comprising a third contact plate extended into one end face of the annulus chamber, wherein the first contact plate and the second contact plate are arranged on one of the rakes and the third contact plate is arranged on the other rake; a conductive ball arranged in the annulus chamber; wherein an open groove is defined between the first contact plate and the second contact plate, wherein a distance between the two dents is larger than a diameter of the conductive ball; when the rolling-ball switch is rotated to a second predetermined angle, the conductive ball is in contact with the first contact plate, the second contact plate and the third contact plate.