Patent GB-470497-A (GB)
Title: Means for turning rotatable control shafts to predetermined angular positions
IPC: H03J5/12
Filed: 1935-11-16
Abstract: 470,497. Locking levers. LEISHMAN, L. J. Nov. 16, 1935, No. 31751. Convention date, Dec. 15, 1934. [Class 80 (iii)] [Also in Groups XXXVI and XXXVIII In a device for angularly positioning a shaft, e.g. the shaft of a condenser, valve switch, &c., a member adjustably mounted on the shaft co-operates with a manually operated pivoted lever and a second lever operated thereby in such a manner that when the manually operated lever is depressed, the member to be adjusted engages either of the levers and is rotated thereby until stopped by the closing together of the levers. Several members adjustably positioned at different angles may be operated simultaneously by the two levers. The apparatus may be used for simultaneously tuning wireless and television sets, a plurality of pairs of unstable members being preset to positions corresponding to the desired tuning position and operating levers corresponding to the stations being provided for each pair of members. The Figure shows a single unit for positioning two members A, C the member A being adjustably supported on a shaft S and the member C on a bush 4 on the shaft. A manually operated lever F is pivoted at Q and operates a lever L through a pin-and-slot connection I, P. When the lever F is depressed against spring control, the lever L is raised and the arms A, C are collected by the engagement of tappets Y, Y<2> with the levers and rotated into a horizontal position when the levers L, F are closed together. A plurality of such units may be employed for tuning wireless or television sets simultaneously, e.g. a plurality of arms A are adjustably mounted at different angles on the shaft S of a first tuning condenser and the arms C are adjustably mounted on corresponding yoked bushes 4 which are connected to a second tuning condenser. Levers F, L are associated with the pairs of arms A, C the levers F protruding through slots in a front panel. The necessary adjustments of the arms A, C may be effected by screws RT which are accessible through slots in the panel when the arms A, C are aligned by the levers F, L in the horizontal position. In modifications, the arms A, C may be mounted on separate shafts and. the levers F, L may be pivoted together, the levers F having a slot connection with the shaft Q. The Specification as open to inspection under Sect. 91 describes also a system wherein two adjustable arms may be aligned with a stop member directly by hand or through a system of pulleys or tappets. That Specification also describes electric control systems for simultaneously controlling two shafts. In one arrangement, Fig. 17 (Cancelled, not shown), the separate shafts are positioned by levers operated by solenoids, the solenoids of the shafts being connected in pairs to control switches so that operation of a push selectively positions both shafts ; in a further arrangement, Fig. 18 (Cancelled, not shown), one shaft is set directly by hand while the other is electrically operated by solenoids selectively operated by a switch on the hand setting means of the first shaft. In further arrangements, Figs. 19, 20 (Cancelled, not shown), the positions of each shaft may be determined by selectively operated detent magnets co-operating with notched discs on the shaft which is rotated by a solenoid, or by short-circuiting the armature of a motor for driving the shaft when a rotatable contact engages a marked contact of a series of adjustable contacts on a stationary support. This subject-matter does not appear in the Specification as accepted.