Abstract: Radio tuner assembly with guide means for automatically maintaining the axis of the pinion gear in radial alignment with the crown gear on the tuner shaft. The tuner shaft is rotatably coupled to one end of the guide means. The pinion gear shaft is slidably and rotatably coupled to the other end of the guide means. The pinion gear shaft is coupled to a manual tuning control shaft through a universal joint connection. This arrangement provides a range of adjustable positions for the manual tuning control shaft relative to the radio tuner front panel while automatically maintaining the axis of the pinion gear in radial alignment with the crown gear.

Abstract: A pushbutton assembly has an actuating arm with a body portion and an outer end portion connected to the body portion by a narrowed portion. A pushbutton having a cavity and a slot leading from the rear wall to the cavity is retained on the arm by slipping the arm through the slot until the end portion enters the cavity, then twisting the end portion slightly around the longitudinal axis of the arm. The pushbutton can be released by realignment of the arm end portion with the body portion.

Abstract: In a pushbutton type tuner assembly for a radio receiver the treadle bar drive gear, which is coupled to the manual tuning knob through the crown gear and the clutch mechanism, is biased into meshed relation with the treadle bar gear through a pair of lever arms mounted for pivotable movement about fixed pins, and a pair of springs. With the end of the treadle bar gear shaft supported in an aperture in the side wall of the tuner, the first lever arm applies a moment to the treadle bar shaft through the bias of a spring secured to the front wall of the tuner, thereby holding that shaft tightly against the supporting aperture wall. The second lever arm applies a moment to the pinion gear shaft through the bias of the second spring which couples the two lever arms together and adds to the moment of the first spring. The two moments provide balanced radial forces on the gears which eliminate backlash and maintain the two gears in a properly meshed relation.