| 摘要 |
617,098. Adjusting radio apparatus. PHILIPS LAMPS, Ltd. May 1, 1946, No. 13168. Convention date, Jan. 14, 1942. [Class 40 (v)] In a system for setting a circuit element, such as a slidable electrode condenser to a number of predetermined positions, of the type in which a follower coupled to the element co-operates with a number of pre-set screws spaced round the circumference of an adjustable disc, the working end of the follower is given a truncated conical profile while the corresponding part of each screw has a curved profile and the maximum differences in height of successive screws is limited to that of the conical portion of the-follower. Figs. 1 and 2 show an arrangement in which follower 14 of condenser 15 is spring urged into engagement with screws 7, having graduated heights and limited in their travel in threaded and smooth bore holes respectively in discs 23 and 9 by bushes 11, the discs being mounted on adjustable shaft 4, springs 21 are provided to urge the screws into engagement with their threaded holes and thus eliminate axial play. A detent system, in which spring urged roller 18 cooperates with notches 17, is provided. In a modification (Figs. 4 and 5, not shown), the relative movement of screws is limited by an arrangement of interacting flanges mounted on the screws. A roller mounted on a pivoted arm may be interposed between the screws and the follower to prevent the transmission of tangential forces from the former to the latter (as in Figs. 7 and 8, not shown), the screw heads being flattened in this case. If a large number of pre-set positions is required successive screws may be arranged alternately on two circles, the follower having a radially aligned wedge-shape profile (as in Figs. 9, 10 and 11, not shown). In the arrangement of Figs. 1 and 2 rotation through more than 360 degrees has to be prevented owing to the large difference in height between the " first and last " screws. This restriction may be removed (as in Figs. 12-14, not shown), by arranging for a lever to lift follower 14 at the appropriate setting of the discs by means of a further lever co-operating with a suitably profiled cam mounted on the disc 22. The system may be used with a remote control system. |
