Patent GB-506362-A (GB)
Title: Improvements in or relating to prepayment mechanisms
IPC: G07F15/06
Filed: 1937-11-26
Abstract: 506,362. Prepayment mechanism for meters. BRITISH SANCAMO CO., Ltd., and WICKHAM, A. H. Nov. 26, 1937, No. 32740. [Class 27] Prepaying basic charges ; indicators.-In a prepayment meter mechanism having means for making a fixed charge in addition to a charge for commodity, a single indicating device is provided in which credit is indicated in commodity units and any arrears charge in cash values. When the mechanism is in a credit condition, the crediting and debiting movements transmitted to the quantity or credit registering mechanism by coin insertion and by collection of fixed charges respectively are transmitted by way of one gear train, these movements being transmitted by way of another gear train to arrears computing means and the indicator when the mechanism is in an arrears condition. The indicator comprises a pointer 63 and a fixed dial 62 marked in commodity units and cash values as shown, the pointer being carried by a shaft 61 which a spring 68 tends to rotate clockwise to a maximum arrears position. The credit registering or quantity mechanism A comprises a wheel nut 31 which is moved backwards and forwards along the threaded portion 30 of a shaft 29 and controls an electric supply switch 'as described in Specification 414,070, the shaft 29 being rotated by coin insertion and the nut 31 being rotated by engagement with a long pinion 32 driven by the consumption meter through a crown pinion 34. The meter drives one sun wheel 47 of a differential IV the other sun wheel 46 of which is driven from the shaft 29 while the planet wheel 51 is geared to one sun wheel 56 of a differential III, the planet wheel 60 of which is carried by the indicator shaft 61, the other sun wheel 57 being connected by gearing 58, 59 to a wheel 18 which meshes with a wheel 69 on a shaft 70 and also with a wheel of a train 17 connecting it to a shaft 15 carrying the planet wheel 14 of a differential I. The sun wheel 10 of differential I is driven by a fixed charge motor and the other sun wheel 12 is connected by gears 13, 23 to one sun wheel 22 of a differential II, the other sun wheel 20 of which is rotated by coin insertion, while the planet wheel 24 is on a shaft 25 in driving connection with the shaft 29 through a commodity price change unit 28. A spring 72 surrounds the shaft 70 and is secured to the framework and a collar 71 having a lug 73 co-operating with loose lugs 74, 75, 76 and a fixed stop 77 so that a number of revolutions of the shaft 70 is permitted with positive arrest in either direction. When the mechanism is in credit, or, as shown, at zero position with no credit or arrears, insertion of a coin causes rotation of the shaft 25 and also of the shaft 29, the sun wheel 22 being looked by the fixed charge mechanism. 'Rotation of shaft 29 sets forward the quantity nut 31 and, through the differential IV and sun wheel 56, rotates the pointer 63 to indicate a credit, the sun wheel 57 being locked by engagement of the lugs 73 . . 76 with the stop 77. During consumption, the meter drives the sun wheel 56 and shaft 61 in the opposite direction. The fixed charge motor drives the sun wheel 22 and rotates the shaft 29 in the opposite direction from that of prepayment to decrease the credit indication. When the pointer 63 reaches zero the supply is cut off, and the shaft 29 now being locked, the fixed charge motor drives the shaft 70 to tension the spring 72, and also rotates the sun wheel 57. for the pointer 63 to indicate arrears. The insertion of coins, while the device is in arrears, again rotates the sun wheel 20 but the 'movement, owing to the tendency of the stressed spring 72 to unwind, is transmitted to the spindle 70 andto the sun wheel 57 until the arrears are paid off and the pointer 63 again reaches zero.