Patent GB-344918-A (GB)
Abstract: 344,918. Totalizators. HAMILTON, R. M., St. Andrew's Works, Slough. Dec. 9, 1929, No. 37775. [Class 106 (i).] In an electric totalizator system, the readings of the counters are transmitted digit by digit to a common set of transmission lines to which are coupled successively and synchronously the corresponding digit sections of the indicators, the coupling being controlled by sequence switches at the counting and indicating stations connected by synchronizing lines. The denominational sections of the counters of which one only is shown, namely 12, are connected seriatim to the ten lines 16 by a double bank 19, 20 of a master sequence switch 18 of the pre-selector type. The lines are led to each of the indicator stations 17 in multiple and are connected there to respective relays MA .. MK. At each station is another pre-selector switch 25 one double bank of which 26, 27 serves to couple up the wipers 29 of the indicator digit sections in turn and another bank 32, 33 is wired to the corresponding stepping magnets 36. The switches 18, 25 are maintained in step with one another by means of further banks 21, 22 and 42, 44 connected by synchronizing lines 45. The operation of the arrangement shown is as follows. Both switches having been zeroized by the application of positive potential to their wipers 23, 24, 40, 41, relay DH becomes energized, locks up, and breaks the zeroizing circuit at DH<2>. At DH3 the drive magnet 50 is coupled with the synchronizing lines and at DH<1> the synchronizing lead 39 is partially completed. If any impulse traverses the line 52, owing to want of synchronism between the switches, the magnet 50 is operated until the master switch reaches the position corresponding with that of the indicator switch. When the indicator sequence switch has been zeroized, positive potential traverses line 55 to energize relay EH, which then locks up, and at its contact EH<1> completes the synchronizing circuit. With the two switches in step relay DF is energized and its contact DF<3> applies potential to line 38 but relay EB is not operated as this awaits relay EA. As contact DF<2> is now closed, positive potential is extended through the meter section 12 to one of the transmission lines 16 and one of the relays MA .. MK is thereupon energized and locks up. This causes a contact MA<2> .. MK<2> to complete circuit through line 28 to the indicator section 29 and thence through line 31 and relay contact MA3 .. MK3 to line 35 and the stepping magnet 36. Consequently the indicator section wiper advances until it reaches a line 31 connected to the operated relay contact MA<3> .. MK<3> whereupon the magnet is cut off and the potential passes to a line 37 and the relay EA. With the last-named energized, the synchronizing circuit is opened at EA<1> and the signalling circuit at EA<2> and the master switch is consequently rendered inactive and the operated relay MA .. MK released. The indicator switch driving magnet 54 is now operated through contact EA<5> to break the short circuit of relay EB at 53 and this relay interrupts at EB<1> the synchronizing circuit, at EB<2> the holding-circuit for relay DF, at EB<3> the driving magnet circuit, and at EB<4> the circuit of relay EA. The indicator switch therefore advances one step and the master switch 18 follows suit so as to couple the next meter section with the transmission lines whereupon the same sequence of operations takes place. In the arrangement shown in the drawing accompanying the Provisional Specification (Fig. 1) two indicators each composed of three denominations 13, 14, 15 are adapted to be operated to show the values on the corresponding denominations of the meter 10,11,12, the denominations being successively coupled to the common transmission lines (of which only three viz 1, 2 and 3 are shown) under the control of a master sequence switch 18 and indicator sequence switches 21. The sequence switches are synchronized by the lines 4, 5, 6 connecting banks of the indicator sequence switches and bank 28 of the master switch. Specifications 333,258 and 334,270, [both in Class 106 (i), Calculating &c.], are referred to.