Patent GB-498306-A (GB)
Title: Improvements in prepayment mechanism for meters
IPC: G07F15/02
Filed: 1937-07-05
Abstract: 498,306. Prepayment mechanism for meters. ENGLISH ELECTRIC CO., Ltd., TILSTONE, G., and DONELLY, J. F. July 5, 1937, No. 18632. [Class 27] Coin action, with stationary coin forming abutment and with delivery proportionate to value of coin.-In a prepayment meter operable at will by coins of different value, rotation of an operating handle displaces a coin-gauging member until it is arrested by the coin, and the coin-gauging member positions a stop member which arrests operation of the quantity mechanism when it has been set forward by an amount appropriate to the value of the coin. As shown, a main operating shaft 12 drives, through gearing 26, a square shaft 14 carrying a drum 15 with a helical cam groove engaged by a finger 16 on a slidable coin-gauging element 18 working in a stationary coin pocket 3 of insulating-material. The gauging element 18 also carries a gate plate 17 with slots 20 of different depth co-operating with a credit disc 21, loose on shaft 12, and notched to provide a series of steps at differing radial distances from its centre. Disc 21 is adapted to be driven by a roller 22b engaging a notch therein and carried by a spring-loaded arm 22a pivoted on a driving disc 22 secured to shaft 12. In operation, the gauging element is moved into the coin pocket by the drum 15 until it is arrested by the coin, the drum 15 then moving back against the action of a spring 19. The gate plate 17 consequently assumes a position determined by the diameter of the coin, and with the slot corresponding to the coin in register with the credit disc 21. The driving disc 22, by means of its roller 22b, drives the credit disc 21 until one of its steps engages the bottom of the slot in the gate plate, the roller 22b then escaping from the notch in the credit disc and the latter having been rotated by an amount appropriate to the coin. If the coin is not of a correct diameter, the driving disc 22 is arrested by the engagement of ratchet teeth 25 thereon with the edge of the gate plate 17, the ratchet teeth clearing a slot in the gate plate with coins of correct diameter. If no coin has been inserted, a pawl 17a at the edge of the gate plate engages the ratchet teeth 25 to arrest the driving disc. Towards the end of the forward rotation of shaft 12, a shutter uncovers the bottom of the coin pocket under the control of a cam disc 34 on shaft 12, and an inclined finger 25a on driving disc 22 moves back slightly the gate plate 17 and coin-gauging element 18 to allow the coin to fall into the till. The periphery of the driving disc 22 is cut away beyond finger 25a so that it next releases the gate plate which moves forwardly to its full extent under the action of spring 19 to clear driving disc 22 and bring pawl 17a into engagement with the ratchet teeth 25 on the disc. Shaft 12 can now be turned back to return the parts to their initial positions. If, however, the coin is fraudulently wedged in the coin pocket, the above full forward movement of the gate plate is prevented, and the gate plate engages under the tip of finger 25a to prevent the return of shaft 12 and subsequent additional credit being obtained for the same coin. The movement of the credit disc 21 is conveyed by a one-way ratchet-and-pawl drive 23, and a price-change gear 29 to the quantity differential. In an alternative construction, the coin pocket is in two telescopic sections, one of which is secured to a rod carrying the gate plate 17 and constitutes the coin-gauging element. In another construction, the slotted rotary coin-slit closing drum (see below) serves also as the coin pocket, the pocket 3 being dispensed with. The slot in the barrel does not extend right through, and the barrel is turned through 180‹ during initial rotation of the shaft 12 to bring the opening in the slot opposite the coin-gauging element 18. Coin-slit closing-devices.-A diametrally slotted barrel 5 is interposed between the coin pocket 37 and coin insertion slot. A cam 9 on the shaft 12 displaces a rack 7 during its initial rotation, and the rack turns the barrel to close the insertion slot. A catch holds the rack and barrel in this position during the gauging and crediting operation. When the barrel 5 serves also as the coin pocket, its slot does not extend right through ; it is turned through 180‹ during initial rotation of shaft 12, and serves as a coin trap. Price-change mechanism.-The coin-operated shaft 30 of the quantity mechanism carries a graduated series of gears 29 selectively engaged by a pinion 33 mounted in a carrier 32 slidable on a shaft 31 driven by the crediting disc 21, each gear 29 corresponding to a different price per unit. Carrier 32 is adjustable along its spindle by a screw-and-nut mechanism which also operates a price indicator of the cyclometer type.