Patent GB-481602-A (GB)
Title: Improvements in or relating to prepayment electricity meters
IPC: G07F15/00
Filed: 1936-09-15
Abstract: 481,602. Prepayment mechanism for electricity meters. FERRANTI, Ltd., and PRINCE, J. Sept. 15, 1936, No. 25098. [Class 27] A prepayment electricity meter comprises means into which a coin of any one of a number of pre-selected denominations may be directly inserted and a longitudinally movable member which can then be effectively moved in one direction only by manual pressure applied to a pushbutton whereby a switch is closed and a " storage " device or quantity-mechanism operated to retain the switch closed until the quantity of electricity prepaid has been consumed. In one construction for use with pennies and shillings, two push-rods 1, 2, Fig. 1, for operating the switch closing mechanism and the " storage " device respectively, project from the meter casing 4 into an outer case 3 containing the coin mechanism. The switch closing and storage devices with the push-rods 1, 2 are similar to those described in Specification 430,757. A penny or a shilling is inserted through separate slots into a compartment 7 or 6 in a movable carriage 5. The coins project through the narrow portions of slots in a base-plate 8, Fig. 4, moving with but displaceable relatively to the carriage 5, which is then moved towards the casing 4, the penny or shilling engaging the push-rod 2 and pushing it in to set the " storage device forward different amounts according to the value of the coin. When the carriage 5 reaches its inner position, the plate 8 meets a stop 20 which displaces it and allows the coin to drop through a wider portion of the corresponding slot in the plate. A lateral lug on the plate 8 also rocks a pawl 19 pivoted on the carriage to allow the carriage and push-button 14 to be returned to their initial position by a spring 17. Normally, the pawl 19 engages a rack 18 to ensure a full stroke. The rod 1 is pushed in to close the switch by a lever 27 pivoted at 25 to the carriage and controlled by a spring 26. An arm 28 of this lever meets a stop 29 whereby the lever is rocked to allow the rod 1 to be returned by a spring and open the switch if a coin is absent and the push-button is held in its depressed position. A double pawl engages over the coins and retains the carriage 5 in its moved in position in the event of the coins failing to drop through the plate 8. In a modification, Figs. 10 and 11, the shilling 32 or penny 33 is inserted through a single slot at the top of the casing 3 and fall between pivoted, spring-pressed, tapering guides 30. The rod 32 is branched within the casing 3, one branch 34 being opposite the penny 33 while the other .branch 35 is opposite the shilling 32. During the return of the carriage, carns 38 act on hinged flaps 36 carried by the guides 30 to rock these flaps and open the guides to discharge the coin therein. In further modifications, the coins inserted through separate or a single slot act edgewise on the push-rod 2. In another modification, the coin actuates the push-rod 1 for operating the switch as well as the push-rod 2. According to another construction, the inserted coin remains stationary while the carriage is moved to an extent dependent on the value of the coin and actuates both rods 1, 2. In this construction, Figs. 19 and 20, the coins are inserted through separate slots to rest in slots 9 or 10 in a base-plate 8, the coins while being inserted moving an arm 50 aside to rotate a lever 51 from behind a wedge 52, thus allowing the carriage 5 to be moved up to the coin which prevents further movement. During the return movement of the carriage 5, a spring-controlled lever 54 strikes an upturned end 58 of the floor 8 to displace the floor and discharge the inserted coin. The coins may be inserted in a single slot, a forked channel leading the respective coins to their operative stationary positions. The coins may also be inserted in an edge-on position. Specification 9905 /99, [Class 27], also is referred to.