Patent GB-304707-A (GB)
Title: Improvements in or relating to electric remote control apparatus
IPC: H02J13/00
Filed: 1927-10-24
Abstract: 304,707. Lyons &. Co., Ltd., J., Goddard, A., Douglass, G., Igranic Electric Co., Ltd., and Wright, S. R.. Oct. 24, 1927. Selective signalling apparatus.-Relates to the control apparatus of a signalling system wherein the receiving apparatus comprises a plurality of numeral drums adapted to display a composed signal. Each drum is driven step-by-step by a rotor which is operated by the cyclic energization of a plurality of field magnets. Control apparatus, Figs. 2, 5 and 6. Each receiver rotor, which in the system described has three exciting magnets, is controlled by cam discs 4, 5, 6, Fig. 2, mounted on a shaft 7 rotated through a friction clutch 11 by a shaft 30 of an electric motor. The discs 4, 5, 6 co-operate with contacts in circuit with the respective receiver magnets and the teeth on the discs are relatively staggered in order to ensure cyclic energization of the receiver magnets. Selecting keys 1 cooperate with the discs in such a manner that depression of a key appropriate to a particular numeral projects it into the path of a stop 12 which stops the rotation of the discs 4. 5, 6 after the required number of cyclic energizations are effected to set up at the receiver the corresponding numeral. A depressed key is held locked by a projection 14 engaging a plate 13 but is released upon subsequent operation of another key. Associated with the selecting apparatus, Fig. 2, is a control disc 15, Figs. 5 and 6, which is adapted to control the driving motor. This disc is driven from the motor shaft 30 through a friction clutch and is adapted to control a switch 17 in the motor circuit. When the apparatus is at rest a projection 32 on the switch 17 lies in a depression 18 on the periphery of the disc and thereby opens the motor circuit. In order to start the apparatus a plunger 2 is depressed to move, through the intermediary of a pawl 21 and ratchet wheel 25, the disc 15 through a few degrees and consequently rotate the switch 17 to close the motor circuit which is maintained during one revolution of the disc. During operation the selecting discs 4, 5, 6 and the control diso rotate together until the discs 4, 5, 6 are stopped by the selecting key when the control disc continues to rotate until the motor circuit is opened. Just prior to stopping, the control disc operates a buzzer and when resting in its stopping position an illuminating circuit is closed for the display drums. When the plunger 2 is depressed the pawl 21 is moved into engagement with the rachet wheel by the spring 31 which however when the rotation of the disc 15 is initiated is moved out from engagement with the pawl to prevent interference in the event that the plunger is depressed during operation. Alternatively starting can be effected by a push button switch which short-circuits the motor control switch 17 during starting. Modified system, Figs. 8 and 13. In a modified control system the cam discs 38 are mounted on a drum 36, Fig. 8, connected through a friction clutch to a shaft 33 which is coupled to an electric motor by an electromagnetic clutch 67. Selection is effected by a dial 39 which is adapted to be locked by a lock 40 and is provided with a stop 41 adapted to co-operate with a projection 42 on the drum 36. The shaft 33 also carries an arm 51 bearing contacts 52, which during rotation successively engage fixed contacts 53 .. 56, Fig. 13, in order to operate respectively auxiliary signals 58, 59 and recording mechanism 60 and to effect stopping of the electric motor driving the shaft 33. In the system shown in Fig. 13, four display sets D each comprising four individual numeral drum and rotor elements are under the control of four complete control units Teach consisting of four units of the type shown in Fig. 8. The operation of each control set T is under the control of a push button 61.. In order to. transmit a predetermined signal the selecting dials 39 of the appropriate set T are set and the corresponding push 61 is operated to energize the appropriate clutch 67 and relay 68. The relay closes the circuit of the motor 66 and an auxiliary circuit for the clutch and locks up so as to maintain the motor and clutch circuits after release of the push 61. The cam discs 38 are thus driven, until stopped by the selecting dials, to set the respective rotors into corresponding positions. The shafts 33 however bv reason of the friction coupling continue to rotate to move the contacts 52 successively over the contacts 53 .. 56. Engagement with the contacts 53, 54 successively operates gongs 58, 59 of different pitch and with the contact 55 closes a circuit for a recordermagnet 60. Upon engagement with the contact 56 the holding circuit of the relay 68 is shortcircuited over the contacts 70, 71 of the push 61, which is at normal, to cause release of the relay and consequently de-energization of the clutch 67 and stopping of the motor 66. Release of the relay 68 simultaneously closes a circuit over contact 78 and normal contacts 74, 75 of a press button switch 62 for a relay 64 which illuminates display lamps 69 at the receiver. When upon subsequent operation to transmit another indication the relay 68 is again energized, the illuminating circuit is opened. If however it is desired to terminate the illumination prior to another signal, the push 62 is depressed to open the circuit at contacts 74, 75 and to close a circuit at contacts 76, 77 for the appropriate recorder. Upon release the button 62 returns to an intermediate position out of contact with the contacts 74, 75 but is fully restored by a. mechanical connection upon subsequent depression of the button 61. The line circuits are shunted by condensers 80 and the contacts associated with the cam discs are shunted by high resistances in order to prevent sparking. Circuit breakers 79 are controlled by the members 40 which lock the selecting dials in position. The cams 38, Fig. 8, in addition to controlling the line contacts of a receiver unit also operate by means of a common linkwork a step-by-step recorder drum. bearing numerals. Moreover time recording drums driven by a clock are provided in order that a record of the indication and the time of transmission may be obtained when the appropriate record magnet 60 is operated to depress a printing platten. Specification 292,275 is referred to.