Low profile pushbutton tuner with improved carriage moving mechanism

Claim 1

In a tuner assembly comprising a support, a part movably mounted on said support, a tuner, an operative connection between said part and said tuner whereby said tuner is tuned in accordance with the position of said part, and a plurality of manually actuated keys mounted on said support and individually movable in a given direction between operative and inoperative positions, each of said keys having a cam thereon adjustably positionable about an axis, a plurality of arm means, one for each key, articulately mounted on said support, said part having a plurality of apertures, a portion of each of said arm means being received in a corresponding aperture, each cam, when its key is in operative position, engaging and moving the corresponding arm means to position said part and thereby control the tuning of said tuner; the improvement which comprises said arm means normally loosely engaging said part, the cam of the operative key and the corresponding arm means comprising means effective to cause that arm means to firmly engage said part, thereby accurately to position said part substantially without lost motion; said arm means comprising a pair of arms independently articulately mounted on said support and each having a portion received in a corresponding aperture in said part, each of said cams having a pair of cam surfaces, each of said surfaces being effective to engage a different one of said arms and to urge said different one of said arms into said firm engagement with said part as the corresponding key moves to its said operative position.