Patent GB-732350-A (GB)
Title: Improvements in and relating to prepayment mechanism for gas meters and electricity meters
IPC: G07F15/04
Filed: 1951-09-21
Abstract: 732,350. Prepayment mechanism for meters. SMITH METERS, Ltd., MIDLAND BANK EXECUTOR & TRUSTEE CO., Ltd., [Representatives of CHARLES, A.], and CHARLES, J. A. Oct. 13, 1952 [Sept. 21, 1951], No. 22205/51. Class 27. A prepayment gas or electricity meter has a two-ratio gear included in the debiting train so that payment is at a high rate until a predetermined quantity of the commodity has been consumed and, during consumption at the higher rate, a shaft 49 connected to the gear train drives reversely a pair of discs 5, 58, which have been set forward to an extent corresponding to the predetermined quantity, until a pin 45 drops into a slot 65 in the disc 5 and through a link 43 to a pivoted spring-loaded gear-change lever 24, changes the gear train to operate the debiting mechanism at the lower rate and to disconnect the drive to the discs. In the higher rate position as shown in Fig. 2, the drive from the gear 40 on the main meter shaft 22 to a gear connected to the prepayment mechanism is through step-up gears. 39, 37, 42, but when the lever 24 is displaced to the lower rate position, a direct drive between gears 40, 42 is provided by an idler pinion, 25 on the lever and, as the gears 37 and 39 on the lever are disengaged from the drive, the drive 38, 48 to the shaft 49 for the discs is also inoperative. The shaft 49 is connected through worm gearing and an intermittent feed device comprising a singletoothed element 51 and a mutilated tooth section of a pinion 52 to a pinion 53 embodying a friction drive or, preferably, a spring-pressed ball 59 in engagement with a toothed member 54. From the member 54, the drive is taken through a plate 56 having a pin 57 which can be engaged in any one of a number of holes 90 in the disc 58 and from the disc 58 to the disc 5 by a pin 60 working in a slot 91 in the disc 5. By pulling out a knob 62, the discs 5, 58 and the plate 56 can be separated and the pin 57 engaged in a different hole 90, in order to vary the quantity charged at the higher rate. Initially the disc 58 rotates alone until the pin 60 reaches the end of the slot 91 and then both discs rotate together until the pin 45 drops into the slot 65. A small depression 76 just before the slot 65 and a flat on the end of the pin ensures that the pin enters the slot with a definite action and it is held in the slot by a spring-loaded arcuate latch 67. A re-setting lever 6 is connected by a spring 12 and a pin-andslot connection to a gear sector 11 engaging a pinion 55 driving the disc assembly 5, 58 and, on raising the lever by a ramp 8 on the coin box 7, the disc assembly is re-set clockwise, the click or friction drive 59, 54 allowing this re-setting and an adjustable eccentric stop 72 limiting the movement of the gear sector. During re-setting, the disc 58 moves relatively to the disc 5 until the pin 60 reaches the end of the slot 91 and, during this movement, the latch 67 is withdrawn and the pin 45 is lifted out of the slot 65 by a cam surface 66. In a modification, the plate 56 and pin 57 are omitted and the discs 5, 58 are directly re-set by a shaft extending outside the meter for rotation by means of a suitable key, the rotation of the shaft being limited by an angularly adjustable stop also operated from outside the meter by a key. The meter is fitted with a normal rotary disc having two different coin slots and the disc is adjustable after removal of a panel held by a rotary catch which may be associated with the locking lug for the coin tray. Indicators. A legend, such as RENT NOT PAID; is provided beside the indicator showing the amount of commodity for which prepayment has been made and, when the rate is changed to the lower rate, a tab 13 having a legend PAID and pivoted to the gear-change lever 24 is raised to mask the NOT PAID wording. Numeral markings are provided on a flanged disc 63 attached to the disc 58 and are visible through a window to indicate progressively the amount of consumption still to be paid at the higher rate.