Abstract: A rotary control knob apparatus includes a stationary knob retainer having a cylindrical post and an annular knob that slides over the retainer post, where the exterior periphery of the retainer post has a distributed array of compliant protrusions that contact the inner periphery of the knob to provide a resilient sliding interference fit between the knob and the retainer post. In a preferred arrangement, the retainer is secured against the rear surface of a control panel trimplate, and the knob is axially captured between the trimplate and a retainer flange extending radially outward from the base of the cylindrical post.

Abstract: A pushbutton for an automotive control panel has a button portion extending through a hole in a trim plate and an enlarged skirt portion behind the plate, and is spring loaded to push the skirt against the rear surface of the plate. A ledge surrounding the button opposes the rear surface. The pushbutton is painted and paint on the ledge causes the skirt to stick to the rear surface of the plate. To prevent sticking, pointed spacers are molded on the ledge so that only the spacer points engage the plate. Sticking from paint adhesion is minimized due to the small amount of paint on the spacer points. Alternatively, the pointed spacers are formed on the rear surface of the plate.