DUST PROOF SLIDE SWITCH
Original Publication Date: 1990-Mar-01
Included in the Prior Art Database: 2001-Nov-16
The design provides a slide switch with three positions actuated with a round shaft pmtruding from the switch hous- ing. Sliding the shaft provides the slide switch action, while twisting the shaft provides the reset action. The incorporation of the shaft and bearing provides the switch contacts with basically a dust proof and chemically resistant environment in which to operate. Attached to the base are two spring loaded caliper type fixed contacts. A thin shaft with a bent end is inserted thru the bearing. The sliding shaft is pushed over this shaft and locked to it by forcing a tab at the end of the contact into a cross drilled hole of the shaft. The fixed contact has a fin which carries spring contacts to engage with the reset contacts when the shaft is twisted against a biasing spring. A molded bat is pressed on the knurled end of the bent end of the shaft. The bat can now be moved sideways taking the shaft with it and internally the sliding contact makes connection with the various fixed contacts. When the bat is depressed it forces the shaft to turn and brings the contact whiskers on top of the fin on the sliding contact into contact with the reset contacts. After releasing the bat, the bias spring will pull the fin back, away from the reset contacts breaking this connection. Three grooves on the shaft provide detent action by engaging the straight round wire detent spring held in the holes of the bearing. The fixed con- tacts as well as the reset contacts have tails protruding through the bottom of the bearing block and can be soldered into the PCB. A sheet metal housing encloses the package tightly and is fastened by tab recessed into the bottom of the bearing block.