Patent GB-468714-A (GB)
Title: Improvements in prepayment meters
IPC: G07F15/08
Filed: 1936-02-08
Abstract: 468,714. Prepayment mechanism for meters. MEASUREMENT, Ltd., CONNOR, R., and CLIFFORD, C. F. Feb. 8, 1936, Nos. 3909 and 15722. [Class 27] In a prepayment meter a swinging frame d, Fig. 1, hinged about a spindle e carries a wheel c which is engaged with either a wheel a or a wheel b, according to the price rate for the commodity, of two gear trains from the meter, the frame being held in either of its two positions by a lug 2 of magnetic material engaging one or other of the poles 3, 4 of a horseshoe magnet. The drive is transmitted to the quantity differential from the wheel c through a wheel f on the spindle e and gearing g, h, i. The trains of gearing from the meter are provided with change wheels for varying the primary rate through the wheel a and the secondary rate through the wheel b. After a predetermined consumption at the primary rate, an arm 5 fixed on a spindle 6 and driven by a friction clutch 7 from a meter driven wheel 8 loose on the spindle engages a spring 9 to swing the frame d and move the wheel c from the wheel a to the wheel b, the frame moving over with a snap action. The spring 9 is slightly flexed by an adjustable abutment 13 to assist the change-over. The primary rate is restored and the frame d reset by an arm 10 thereon being engaged by a lug 11, Fig. 4, on a lever 12 which is connected by a cable 21 to a cam 22, Fig. 5, located at the rear of the cashbox 23. When the cash-box is withdrawn by an official, the cam 22 is moved into the cashbox housing by a spring 25 and the lever 12 is pulled down by the cable 21. A roller 20 on the lever 12 engages and rotates a heart-shaped cam 16 back to a fixed position corresponding to the start of the primary rate. The cam is loose on the spindle 6 carrying the arm 5, Fig. 6, and is rigid with a dial plate 18. A finger 15 rigid with the arm 5 is moved over the dial 18 and the dial 18 and finger 15 are then locked together by a nut 19. This adjusts the position of the arm 5 relatively to the cam 16 and the extent of consumption at the primary rate. When the cash-box is returned, the lever 12 is moved out of engagement with the cam 16 and the arm 10. The change from primary to secondary rate may be effected by hand by means operated from behind the cashbox. It may also be effected after a predetermined time by a clockwork mechanism or a synchronous motor operating the arm 5. The resetting from secondary to primary rate may be effected on a time basis by a synchronous motor, instead of by the cable 21. Indicators.-A pointer actuated by the frame d indicates which rate is in force. A spring strip secured to the pointer actuates a ratchet wheel bearing numbers which indicate how many times the rate change has been affected. Mechanism for prepaying basic charges.-The shaft q of a constant speed or rent charge motor drives through gearing, including change wheels w, Fig. 6, located outside a frame y, the planet carrier of a differential B. High and low speed cams t<1>, v, which control switch tripping mechanism as described in Specifications 444,663 and 446,201, are driven from one sun-wheel r of differential B, the other sun-wheel n<1> being coupled to a sun-wheel m of a differential A. The second sun-wheel k' of this differential is driven by the coin-mechanism, while the planet carrier thereof is driven by the wheel i which is driven by the consumption meter through the rate change mechanism. The K.W.H. gear is mounted in a separate unit 30, Fig. 1, the rate change gear in a unit 31, and the prepayment mechanism in a unit 32 so that each may be readily removable without disturbing the others.