1,210,812. Prepayment meters. C. W. KUECHENMEISTER. 6 Nov., 1967 [28 June, 1967], No. 29733/67. Heading G4V. A coin-operated prepayment meter for controlling the supply of a service such as gas, electricity, or water, disconnects the service at the end of a period of time paid for irrespective of whether the service has been utilized during said period. The meter comprises a timing unit having a motor continuously driving a cam in one direction, a coin acceptance unit driving the cam in the opposite direction on receipt of a coin, and a price-change mechanism in the drive between the coin acceptance unit and cam having a pawl and ratchet wheel drive in which the driving arc of the pawl is adjustable. The cam co-operates with a control switch in an actuating circuit of a cut-off valve in a gas or water supply system or in an electricity supply circuit. Coin action.-The coin acceptance unit comprises spaced plates 61-64 and a slide 65 having members 66, 67 engaging between plates 61, 62 and 62, 63, respectively, Fig. 8. The member 67 has depending lugs 77 passing through an opening in the plate 63. A T-shaped member 74 slidable in a slot 73 in plate 62, has a rack 75 on its lower edge co-operating with a gear 83. An extension 80 on the member 74 extends upwardly at 81 through a slot in plate 64. Plates 61, 63 are provided with aligned apertures 69, the slide members 66, 67 with aligned apertures 70, and plate 62 with an aperture 71. In operation, a coin is inserted in the unit at 85, the coin from the previous operation being located at 86, and the slide pulled outwards. Outward movement of the slide is transmitted to the member 74 by lugs 77, coin 86 and extension 80, until the coin 86 falls into the coin box. The coin 85 passes through aperture 71 at the end of the outward movement to engage the aperture in member 67 and move member 74 to the left when the slide is returned. In a modification, the coin is received in a rotary carrier, Fig. 16 (not shown). A lug (141) at one end of a lever (140) engages an arcuate slot (138) in the carrier whereby manual rotation of the carrier is transmitted by the coin to the lever. A pivoted pawl (142) at the other end of the lever drives a gear (143). A spring- pressed lever passes through an opening (139) in the carrier to eject the coin after the carrier has been rotated a predetermined amount. A spiral spring returns the carrier to its initial position. In a third embodiment, Fig. 19, a coin bridges contacts 192, 193 to energize solenoid 161. A spring-loaded rod 162 having lugs 170, 171 opening and closing contacts 173, 174 in the solenoid circuit, is reciprocated to step a gear 168 through ratchet lever 165. A twoarmed lever 179 carrying a pivoted pawl 181 is rotated by the gear 168. A striker 180 on the two-armed lever rocks member 188 to close contacts 194, 195 and move contacts 193, 194 apart to release the coin into a coin box. A stop 184 disengages the pawl 181 from the gear 168 whereby the two-armed lever returns to its initial position against cam face 186. The cam face is formed on a segmental element 178 adjustable in position. Timing unit.-A continuously running, battery operated, clock motor M drives a cam 32 in one direction through a differential 31, Fig. 1. The coin acceptance unit drives the cam in the opposite direction through gear G and differential 31. The cam carries a pointer 33 co-operating with a fixed scale 34 and operates a microswitch S in the supply. In a second embodiment, the clock motor drives a spindle carrying the cam and pointer. A hollow drum rotatable about the spindle supports a micro-switch and scale and is driven by the coin acceptance unit. In a third embodiment, the motor is rigidly fixed to a gear-wheel driven by the coin acceptance unit with the motor spindle passing through the hub of the gear wheel. The spindle carries a scale cooperating with a fixed pointer and a cam cooperating with a fixed microswitch. Price change.-The gear G of the timing unit is driven from the gear 83 of a coin acceptance unit through crank 90, connecting rod 94, gear segment 95, and pawl and ratchet mechanisms 97-100, Fig. 11. The connection rod is attached to the crank through a slide 91, adjustable in position to vary the amount of time paid for by each coin. In an alternative arrangement, the coin acceptance unit drives a ratchet lever (110) through gear (83), Fig. 14 (not shown). The ratchet lever co-operates with a gear (112) driving the gear (G) of the timing unit. An arcuate cam (120) is adjustable about the periphery of the gear (112) to disengage the ratchet lever after a predetermined movement.