A tuning device for a UHF tuner includes a rotatable drum rotatable step-by-stop by turning a tuning shaft of the tuning device, a plurality of adjustable control elements loosely carried by the rotatable drum and a tuner operating member for operating the tuner to select a desired one of UHF channels. The tuner operating member can be operated by the adjustment of any selected one of the control elements thereby permitting the tuning of the tuner.
A tuner drive assembly for use with a tuning mechanism for selecting one of a limited number of channels in the UHF band. The assembly has a rotatable turret which is driven by the input shaft. The turret has first and second spaced end sections with a plurality of screw elements rotatably mounted therebetween. One screw element is provided for each channel to be selected. Each element has a threaded portion and an internally threaded member normally engaging the threaded portion is mounted thereon for axial movement along the element as the element is rotated. The threaded portion is spaced from both end sections such that the member is permitted to disengage or "run off" the threaded portion at either end of its travel as the element is rotated, thus preventing breakage or jamming of the member and the element. Means are provided which are effective when disengagement occurs to relatively move the member and the threaded portion together to cause re-engagement thereof when the element is rotated in the opposite direction. Means are provided for sensing the axial position of the member in order to corporeally condition the tuning mechanism to select the appropriate channel in accordance therewith. First and second indicating means are provided for indicating the rotational position of the turret and the axial position of the member, respectively.
A channel-selecting, presettable, rotary type tuning device in which there is provided a tuning-position-determining unit having two or more tuning-position-determining elements, whose positions may be adjustable; a slide member operably coupled to a variable tuning element and spring-loaded so as to abut the end of each tuning-position-determining element selected due to the rotation of the tuning-position-determining unit; means for rotating the tuning-position-determining unit so as to select a tuning-position-determining element; means for moving back and forth each tuning-position-determining-element thus selected; and means for temporarily releasing the slide member from its abutment on each tuning-position-determining element thus selected.
