Patent GB-340988-A (GB)
Abstract: 340,988. Totalizators. RICKETS, W. J., St. Andrew's Works, Slough. Sept. 27, 1929, No. 29301. [Class 106 (i).] Relates to means for calculating the ratio between two numerical quantities employing a quotientdetermining apparatus of the Wheatstone bridge type such as described in Specification 340,987 a sufficient selected number of the significant figures of the quantities being taken automatically and the digit values being transmitted to the calculating apparatus. As an example the apparatus is shown applied to a totalizator for calculating the odds. The horse pool apparatus is shown in Fig. 3 and the individual horse apparatus in Fig. 4. To avoid difficulties due to change in the given quantities while the calculation is proceeding, numerical elements of the preselector switch type are employed similar to the follower elements of metering switches such as are described in Specification 333,258, [Class 106 (i), Calculating &c.], which are periodically connected to a meter to receive therefrom a given total and are disconnected or prevented from movement during computation. In the pool apparatus five denominations 271 .. 275 and in the individual horse apparatus four denominations 281..284 are shown. The current for actuating the followers is through lines 651, 650, Fig. 1, respectively, the latter being dead on an insulating segment 65 3on the shaft 75 during the computation, and the former being in circuit with contact N<1> of relay N which is normally closed but is operated when the operation control switch 11 reaches contact 131 to open the contact N<1>, at the same time closing contact N<2>, Fig. 2, to retain contact N<1> open until the Wheatstone bridge pool and horse resistances have been properly set. This being done line 25 is energized to actuate relay Z, Fig. 2, to open contact N<1> and allow relay N to fall off and so allow the follower elements 271 .. 275 to catch up the main numerical quantity meter. The line 26 from the bank 12 of the operation control switch 11 is taken to the contact arm of bank 271 of which the zero and succeeding tenth contacts are connected together and to the contact arm of the next denomination bank and so on through banks 272 .. 275. The remaining contacts are multiplied together to the signal transmission lines 33 .. 37 which are connected to the contacts of the bank 30 of the pool " power-often" selector switch 29. so that the highest denomination meets the foremost arm of the bank causing this switch to stop in a position to put the three arms of bank 31 in circuit with the three highest significant figure denominations. The spindles of banks 271 .. 275 carry also the arms of banks 371 .. 375 which act as master elements to control the follower banks 471 .. 475 so as to bring step by step their contact arms and the arms of the impulsing banks 501 .. 505 to the reading on the banks 271 .. 275. Impulses are thus sent, when line 50 is energized by the operation control switch 11, through the arms of bank 31 to set the pool resistances of the Wheatstone bridge. The second bank 31 of the " power-of-ten" switch has contacts wired to the impulsing banks 501 .. 505 and has three separate contact arms each with a slip ring and secured so as to engage three successive contacts on the bank, the slip ring brushes being connected to the driving magnets of the resistances 158 .. 160 as described in Specification 340,987. A third homing bank 32 is provided actuated through a contact X7 of the relay X after the result (eg. the " odds ") has been shown on the indicator. A homing relay L operates contacts L6 and L7 .. L11 to cause the impulse banks 501 .. 505 to step round their arms bringing the arms of banks 471 .. 475 to the relay contacts L7 .. L11 where they are retained by cross connections through relays E1 .. E5, this position being a step prior to the zero which is thus reached when the contact is broken. The relays E1 .. E5 close contacts E11 .. E15 to send a reply signal to the operation control switch 11 which thus moves off contact 128 and releases relay L, and therefore driving magnets 551 .. 555 to allow the switches to step to zero. Contacts L1 .. L5 are provided to prevent cross connections from banks 371 .. 375 from interfering with the homing action. The horse elements are similar to those for the pool. The action of the apparatus is described in Specification 340,987.