Patent GB-324615-A (GB)
Abstract: 324,615. Hamilton, R. M. July 23, 1928. Totalizators; logarithmic calculators.-In computing apparatus wherein a driven member is displaced proportionately to a desired function of the displacement of a controlling member, the latter includes a relatively movable switch device cooperating with cams or lugs arranged on the controlling member in accordance with the function and producing impulses for actuating the driven member. The invention is described as applied to the calculating of odds totalizators, and the Specification refers in this connection to Specifications 307,816 and 312.970. Logarithmic apparatus. Driven from each horse and pool counter 31, 48, Fig. 1, is an arm 13 carrying a nut 16 slidable along a drum 11 provided with a spiral thread engaged by the nut. Along this thread are formed lugs 23, Fig. 4, spaced logarithmically and adapted to rock a contact arm 15 mounted on the nut to close circuit to a magnet 24 controlling a one-revolution clutch 38 to drive a crank disc 39 and so, through a pawl 43, advance a ratchet wheel 44. The two ratchet wheels 44 thus driven from the horse and pool counters are connected with a differential gear, the planet pinion 51 of which is carried by an odds-indicating drum 52. As the lugs might be inconveniently crowded towards one end of the thread, they may be arranged at, say, twice the correct distance apart at this end and the rate of driving the wheel 44 correspondingly increased. For this purpose a cam-slot on the nut is adapted to displace an arm 68 axially, and so rock a shaft 75 carrying a guard plate 76 variably masking the pawl 43. Circuit arrangements. To prevent closure of circuit to magnet 24 unless a lug 23 is completely cleared by the contact arm 15, additional magnets 62, 63, Fig. 4, are employed. When the arm is rocked upwards it completes circuit for magnet 62, the armature of which is thereupon attracted and is latched up by the armature 65 of the other magnet 63. When the arm is released by the lug and descends, it closes circuit for this magnet 63 and also through armature 63<1> and contact 64 energizes magnet 24, the armature 65 then releasing armature 63<1> to restore the lines to normal. Ticket-stamping " take-out " arrangements. When a ticket is stamped with the prevailing odds the corresponding horse drum 11 is advanced in the same direction as the movement of the arm 13, this being effected by a driving train at 34 between the " take-out " ticket counter 32 and the drum spindle 12. To prevent relative retrogression of the arm a contact 56 driven from the counter 31 is normally engaged by a contact 57 driven through a friction clutch from the takeout counter 32. If the latter is operated, there. fore, while the counter 31 is stationary, the contacts separate and the circuit to the magnet 24 is broken. When a ticket is stamped and the horse drum 11 advanced, the pool drum 11 is also advanced by the same amount multiplied by the odds. To effect this, a circuit is closed at 78, 79 at each movement of the counter 32, to energize a magnet 83, Fig. 2, controlling a one-revolution clutch. The consequent rotation of disc 84 therefore reciprocates a pawl 87 to drive a ratchet wheel 88, pins 89 on which close circuit at 90, 91 to a second and similar magnet 92 to drive a pawl 96 actuating a wheel 97 fixed on the shaft of the pool drum 11. The amount of rotation of this drum at each closure at 78, 79 is controlled by varying the extent of engagement of the pawls 87, 96 with their ratchet wheels, and for this purpose a series of masking latches 98 or 99 is provided along the path of travel of the pawl. The odds drum 52 carries a number of contact strips co-operating with brushes 54, 55 in circuit respectively with magnets controlling the latches. Thus according to the position attained by the odds drum so one or more of the latches 98, 99 is raised to render the pawls less effective. The latches support each other serially to provide against failure of their magnets.