Patent GB-525613-A (GB)
Title: Improved method and apparatus for the remote control of wireless receivers
IPC: H03J1/20
Filed: 1939-02-23
Abstract: 525,613. Distant control of wireless receivers. FOKERD, A. R. Feb. 23, 1939, No. 6067 [Class 40 (i)] [Also in Group XXXVII] A wireless receiver is controlled by means of a stream of impulses generated by an electromagnetically operated interrupter or a handoperated impulse sender and sent over one or other of two circuits to step a shaft in one or other direction. This shaft is normally coupled to the tuning shaft but by means of clutches controlled over further circuits may be clutched to the waverange control shaft or the volume control shaft. Circuit arrangements.-The main switch M1* switches on the set and the control apparatus. To tune the set a button LT<SP>1</SP> or RT<SP>1</SP> is operated to start an interrupter I, shown in detail in Fig. 8 and deliver impulses therefrom to local and distant stepping magnets LT2 and LT or RT2 and RT to rotate a main shaft in both stations in one direction or the other. This shaft at the wireless receiver is normally clutched to the tuning shaft which accordingly is rotated in one direction or the other. The local shaft controls a tell-tale indicator (not shown). Alternatively impulses may be produced by rotating the knob S of an impulse sender shown in detail in Figs. 2, and 3 in one direction or the other. To operate the wave-range changing switch a knob B secured to an insulating contactcarrying disc B5 as shown in Fig. 6 is first pushed in to open contact 10 and close contact 9 and is then rotated to the appropriate position. Circuits are thus made via 9 for the interrupter I and via wiper B1 for one of the pairs of driving magnets and another circuit is made through wiper B2 and a clutch magnet W at the distant station which uncouples the main shaft from the tuning shaft and couples it instead to the wave-change shaft. At the control station the pressing in of knob B uncouples the gear wheel 3, which is geared to the main shaft, from the gear wheel 7 which drives the tuning indicator (not shown) and couples it instead to the wheel 7a which drives the wave-range indicator and is connected to the wipers B1, B2. Consequently the wave-range indicator, the wipers B1, B2 and the distant wave-change switch are driven in synchronism until the wipers B1, B2 find the gap b3. To alter the volume, knob B is withdrawn to close contact 16 and open contact 9 and one or other of the buttons vl, vr is operated to energize magnet V at the receiver to uncouple the main shaft from the tuning shaft and couple it to the volume controlling shaft and to start the interrupter I and cause it to step the distant main shaft in one or other direction. No local tell-tale is operated for volume control. If desired the volume control may be coupled with an on/off switch at the set. Construction of manually operated impulse transmitter.-When the knob S, Fig. 3 is rotated a pivoted contact member s<SP>1</SP> is forced to make intermittent contact with one or other of two fixed contact-pieces according to the direction of rotation by a pin disc s<SP>3</SP>, s<SP>4</SP>, and a spring which tends to keep the movable contact between the fixed contact pieces. Construction of interrupter, Fig. 8.-When the circuit of the interrupter magnet I is made through resistance I6 and lead x<SP>1</SP>, armature I<SP>1</SP> forces contact I' to engage contact I' against a dash pot I<SP>5</SP> and so short-circuits the magnet which at once drops its armature. The circuit is not however re-made again until the dash-pot allows contact I<SP>2</SP> to re-engage contact I<SP>4</SP>. By this means the battery connection from x<SP>1</SP> to x is intermittently interrupted. Construction of step-by-step control and indicating arrangements.-The stepping magnets drive a main shaft 18 in one or other direction with the aid of crown wheels 13c, 13d, Fig. 5, fast with the respective ratchets and pinions 19 on a bar 20 secured to shaft 18 so as to give a free wheel effect between the ratchets and the shaft. A brake shoe (not shown) normally holds the ratchet against rotation and is lifted off at each stroke of a rod carrying the driving pawl. At the transmitting station the shaft 18 is geared to a pinion 3 which is clutched to one or other of two wheels 7, 7a driving indicators according to the axial position of shaft 2. At the receiving station, the shaft 18 is geared to a shaft 24 to which is normally clutched a wheel 31 geared to the tuning shaft 25. On the operation of magnet W, wheel 37 which is geared to the shaft 27 of the wave-band control, is clutched to shaft 24 and the clutch associated with wheel 31 is disengaged by a link 39a. Similarly when V is energized wheel 33, which is geared to the volume control shaft 26, is clutched to shaft 24 and wheel 31 is unclutched by link 39.