Patent GB-572389-A (GB)
Title: Improvements in prepayment meter mechanism
IPC: G07F15/02
Filed: 1943-04-29
Abstract: 572,389. Prepayment mechanism for meters. ENGLISH ELECTRIC CO., Ltd., TAGG, G. F., and WHITEHEAD, R. K. April 29, 1943, No. 6772. [Class 27] In a multi-coin prepayment meter mechanism a coin-gauging device positioned in accordance with the diameter of the inserted coin determines the movement transmitted to crediting mechanism without taking part in transmitting said movement. In the construction shown in Fig. 1 a slidable coin pocket 1 urged by a spring 2 towards a fixed adjustable stop 3 is held in the position shown, in which it is ready to receive a coin, by a lever 9 having a roller 9a engaging a cam 8 on the actuating spindle 4 controlled by the knob 5. When a coin has been inserted in the pocket and the knob 5 is turned clockwise the cam 8 allows the spring 2 to move the pocket against the stop 3. This movement of the pocket first brings the coin against a coingauging member 11 on a slide 12 movable along a rod 13, the movement of the slide thus depending on the diameter of the coin. The slide 12 carries a detent plate having notches 12a, 12b, 12c corresponding to the three coins, say sixpence, one shilling, and one penny, which the meter is adapted to take. If one of these three coins is inserted the slide takes up such a position that on further rotation of the knob a part 16 of a clutch member 22, 21 passes through one of the notches, the clutch members engage, and the crediting shaft 30 is driven through gearing 20, 29 and variable-stroke ratchet gearing 33, 34. As the spindle 4 completes one revolution a cam 25a thereon engages a follower 26 and moves a slide 27 forming the bottom of the coin pocket to allow the coin to drop into the till. If a wrong coin is inserted and the knob 5 is turned the clutchoperating part 16 strikes the detent plate between the notches, the clutch member 22 is withdrawn and the spindle 4 does not drive the gear 20 and the crediting shaft ; the spindle 4, however, is free to rotate and when it has completed a revolution the slide 27 is moved and the coin drops into the till. The position of the slide 12 and a cam 37 carried thereby determines the amount of rotation imparted to the crediting shaft for one rotation of spindle 4. The cam 37 has three portions of different circumferential lengths, that for a shilling being shown in Fig. 7, when the gear 29 is rotated by the spindle 4 and gear 20 it rotates idly at first on the crediting shaft 30, the pawl 33 which it carries being normally disengaged by a spring from a ratchet wheel 34 fixed to the shaft. As soon as a follower 35 carried by the pawl strikes the leading edge 37a of the cam 37 the pawl 33 is rocked and engages the wheel 34 so that the crediting shaft is driven until the follower 35 leaves the trailing edge 37c of the cam. The arc of the sixpenny cam is half that of the shilling one, and that of the penny cam is onetwelfth. The clutch between the spindle 4 and gear 20 comprises two discs 14, 15 fixed to the spindle and carrying a slidable pin 22 normally adapted to engage a pin 21 on the gear. The disc 15 carries a spring-loaded pawl 16 having a projection 16a extending beyond the periphery of the disc and adapted either to engage the detent plate or to pass through one of the notches 12a &c. If the coin is of the right size the projection passes through one of the notches when the spindle 4 is rotated, but if a wrong coin is inserted the projection 16a on the pawl 16 strikes the detent plate, the pawl is rocked and its cam end 16b slides the pin 22 through the discs 14, 15 out of engagement with the pin 21 so that the crediting shaft is not driven. Modifications are described in which (1) the spindle 4 has a cam disc 38, Fig. 9, fixed thereon, this disc having a slot 38a for a pin 40 controlled by a spring 41 and carried by a notched disc 39 fixed to the gear 20 but loose on the spindle 4. With no coin or a wrong-sized coin in the pocket 1 rotation of the spindle 4 brings the edge of the notch in disc 39 against the edge of the detent plate before any crediting is effected, and the disc and gear 20 are arrested. The spindle 4 can still rotate by stressing the spring 41, the pin 40 remaining at rest while the slot 38a turns relatively thereto, the rotation continuing until a cam 38b on the disc' 38 moves the slide 27 forming the bottom of the coin pocket and discharges the coin into the till. The spindle 4 is now allowed to return to its original position as shown, in which the cam 38c returns the coin pocket to a position ready to receive another coin. The pawl-and-ratchet device and the controlling cam 37 therefor may be as described in connection with Fig. 1. Means such as described in Specification 498,306 may be provided for preventing return movement of the spindle 4 until it has turned far enough to discharge the coin from the pocket, (2) the crediting mechanism may be set forward by mutilated gears instead of the ratchet and pawl 34, 33 and the cam 37. In this construction, arranged for two different coins, two mutilated gears 42, 43, Fig. 10, one having double the number of teeth of the other, are mounted loosely on the spindle 4 and are adapted to mesh with the gear 29 on the crediting shaft 30. The gears 42, 43 carry pins 44, 45 set at different radii ; the pin 44 is driven by a pin 48 carried by a disc 46 on the spindle 4 if a pawl 47 passes through a notch in the detent, plate, similarly the pin 45 is driven by a pin 22 carried by a disc 15 if the pawl 16 on the disc can pass through the notch in the detent plate. Thus only the one mutilated gear corresponding to the inserted coin drives the crediting shaft, (3) an electric motor switched on by the insertion of a coin in the pocket 1 in known manner may drive the spindle 4 to perform all the operations automatically, and (4) when a coin is inserted in the pocket a switch is manually operated to close the circuit of an electric motor, as described in Specification 572,403, to rotate the spindle 4 to effect at least the crediting movement and possibly the movement of the pocket.