Patent GB-307818-A (GB)
Abstract: 307,818. Setright, H. R. Dec. 14, 1927. Addition to 269,998. Totalizators.-In indicating apparatus for totalizators as described in the parent Specification, to reduce the amount of current used and to prevent overheating of the electromagnets, means are provided for interrupting the passage of current after the movement of the indicator has been arrested and for retaining the indicator in its set position. The indicator drums (not shown) are frictionally coupled to a constantly driven shaft and each has a sprocket wheel connected by a chain to a second sprocket wheel 14. Figs. 1 and 2. The wheel 14 is secured to a sleeve 15, loose on a shaft 16 and carrying a detent wheel 17 and a follower switch arm 18 having contacts 19, 20 co-operating with a ring contact 23 and ten spaced contacts 24, mounted in a stationary insulating disk 22 secured to the shaft 16. Above the shaft 16 is mounted a panel 25 carrying a pair of electromagnets 26, 27, pairs of contacts 28, 29, and 30, 31, a locking lever 33, 34, and a latching switch member 41. The locking lever has a hook 35 to engage the detent wheel and arrest the indicator drum and carries the armature 37 for the magnet 26 and a bridge piece 38 for the contacts 28, 29. The switch member is a three-armed lever, the arm 41 of which carries the armature 44 for the magnet 27 and a bridge piece 45 for the contacts 30, 31, and the arm 43 of which has a hook 47 forming a latch for the end 39 of the locking lever. The circuit diagram is shown in Fig. 4 the movement of each indicating drum being controlled by a master member 49 driven in synchronism with a registering member of the totalizator. The member 49 carries three contacts 50.. 52 co-operating with a ring contact 53 and two sets of spaced contacts 54, 55 respectively, the contacts 54 being connected together and the contacts 55 insulated from one another and electrically connected one to each contact 24. The contacts 28 .. 31 are protected by condensers 61, 65. By the arrangement of leads shown each electromagnet in turn receives an impulse energising it to make a connection in the circuit of the other magnet and break a connection in its own circuit so that as soon as a magnet has been energised its circuit will be interrupted. With the above described arrangement the total varies continually when the totalizator is operating at a fast rate; if it is desired to vary the total shown, at intervals only, the contacts 28, 29, and spaced contacts 54 may be dispensed with and replaced by a timing rotary switch comprising a constantly rotating arm 66, Fig. 5, a ring of connected contacts 70, and a contact ring 69, the distance between the contacts 70 depending on the time interval. The circuit through the magnet 27 is thus controlled periodically to operate the latch lever, release the locking lever and bridge the contacts 30, 31. By this means the indicator drum has merely to take up a position corresponding to the final position of the master member so that, if the master member has been turned through more than one revolution the indicator drum of that denomination and that of the next higher denomination will only be turned through the necessary angular amount.