Quick zeroing knob assembly

A control knob assembly is disclosed that may be generally used for the quick zeroing adjustment of a dial thereof. A control knob assembly includes a housing with a shaft rotatably supported therein. A ring is coupled to the shaft in such a way that rotation of the ring causes rotation of the shaft. The ring has a plurality of holes distributed therearound and extending longitudinally therethrough from a first side thereof to a second side thereof. A knob is disposed about the shaft adjacent the first side of the ring. The knob is rotatable about the shaft and slidable therealong. A spring is coupled between the knob and ring for biasing the knob towards the ring. A pin extends from the knob to engage one of the holes at the first side of the ring when the spring is free to bias the knob towards the ring. A spring-loaded detent mechanism mounted in the housing engages one of the holes from the second side of the ring. The detent mechanism permits rotation of the ring relative to the housing when the spring is free to bias the knob towards the ring. However, the detent mechanism inhibits rotation of the ring relative to the housing when the spring's bias is overcome by a pulling force that causes the pin to disengage from one of the holes at the first side of the ring.