Patent GB-569001-A (GB)
Title: Improvements in and relating to prepayment mechanism for meters and the like
IPC: G07F5/22
Filed: 1943-07-26
Abstract: 569,001. Prepayment mechanism for meters. CROMPTON PARKINSON, Ltd., and ANGOLD, A. W. July 26, 1943, No. 12147. Addition to 515,223. [Class 27] Prepayment mechanism as claimed in the parent Specification, in which a body 2, 4 normally obstructs the entrance to a coin pocket and is movable to permit the insertion of , a coin into the pocket and to set a caliper in readiness for gauging the coin when inserted, is improved or modified in that the insertion of coins in excess of a predetermined total credit value is prevented by the provision of means comprising a stop 31 adapted to be introduced into the path of movement of the said obstructing body or a part 15 thereof as the crediting mechanism approaches the predetermined limit by an element of or displaced by the crediting mechanism, whereby movement of the said body to free the pocket is prevented until debiting has been effected, this latter operation moving the stop clear of the said body. In the construction shown, the coin slot. (not shown) is formed in a plate 1 and is normally obstructed by a plate 2 sliding by rollers 3 on the plate 1 and carrying a coin-slot entrance jaw 4 coacting with a fixed jaw 5. When a coin is inserted between the jaws 4, 5, the jaw 4 and the plate 2 are depressed if the stop 31 is not in the path of the pin 15 carried by the plate 2 ; thus, the coin is able to enter and to pass through the coin slot, and the crediting mechanism is set forward according to the value of the inserted coin. The crediting cam 88 is fixed to a pinion 6 geared to a wheel (not shown) which is rotated in one direction by the prepayment mechanism and in the other direction by the meter. The pinion 6 drives the units and tens shafts 11, 13 of an indicator through gearing 10, 12, and the shaft 13 is used to control the stop 31. For this purpose a crank-pin 17 on the shaft 13 is adapted to engage and rock one end of a lever 18, the other end of which rocks an arm 14 pivoted on a shaft 16 and having a notch 31 forming the stop. Normally, one end of the lever, which is controlled by a spring 21, bears against a fixed pin 22, but as coins are inserted and credit built up the crank-pin 17 rocks the lever and thereby the arm 14 to bring the stop 31 into the path of the pin 15, so that the jaw 4 is prevented from moving sufficiently to allow a coin to be inserted. The lever 18 acts on the arm 14 through a spring coupling 20, allowing a limited amount of relative motion by stressing a spring 30 to avoid stressing the mechanism. The end of the lever is slotted to engage a pin 26 projecting from a disc 25 loose on the pivot 26 and coupled by the spring 30 to the arm 14. The arm 14 is also loose on the pivot and has a notch 29 normally engaged by a second pin 27 on the disc 25. The lever 18 has a hooked part 32 which, when all credit is exhausted and the flat part 112 of the crediting cam 88 releases the latch 111 to open the switch (not shown) and cut off the supply of the commodity, engages the crank-pin 17 and retains the indicator pointers at zero. Instead of using the shaft 13 to control the stop 31, any suitable part of the crediting mechanism may be used ; for example, the stop may be controlled by movement of the cam 88. The shaft 8 of the cam 88 and pinion 6 is screwed at 7 into a fixed nut 9 so that as the cam and pinion rotate they also move axially until finally, the flat part 112 of the cam comes under the latch 111 and releases it to cut off the electricity supply.