Patent GB-569501-A (GB)
Title: Improvements in and relating to prepayment mechanism for meters and the like
IPC: G07F15/06
Filed: 1943-04-02
Abstract: 569,501. Prepayment mechanism for meters. CROMPTON PARKINSON, Ltd., and ANGOLD, A. W. April 2, 1943, No. 5324. [Class 27] Means for varying the fixed-charge in prepayment mechanism for meters &c., comprising an oscillatable toothed sector wheel 10 oscillating through the same amplitude whatever the fixed-charge rate may be, and adapted to gear with a second toothed wheel or pinion 15, and a one-way drive coupling 21, 22 between the second wheel 15 and commoditycontrol means 34, the said two wheels being relatively adjustable around the axis of oscillation of the sector wheel 10 to vary their period of engagement and therefore the fixed charge. In the construction shown, a constant-speed motor 1 oscillates the sector 10 through gearing 3, a crank-pin 4, connecting rod 5 and a toothed quadrant 7 gearing with a wheel 9 fixed to the sector 10. The latter, as it oscillates, engages the pinion 15 during some part of its oscillation and rotates it first in one direction and then in the other. The pinion 15 is in constant mesh with a gear 13 driving an arm 20 carrying a pawl 21 engaging a ratchet-wheel 22 prevented from backward rotation by another pawl 23a. The wheel 22 drives a sun-wheel 30 of a differential gear through a two-speed gear 27, the other sun-wheel 31 being geared at 33 to a dog 34 adapted to be connected in known manner to the commodity control means (not shown). The planet pinions 36 are mounted on a carrier (not shown) fixed to the shaft 37 which is connected by gearing 38 to a shaft 39, controlled by a torsion spring 40 and an " Arrears " indicator 43. The dog 34 is free to rotate as long as there is any "credit" in the meter, but when the credit cam or the like has returned to its " no credit " position the dog is locked against rotation. The motor now, therefore, rotates the planet carrier and stores up energy in the spring 40. As soon as money is inserted in the prepayment mechanism, the dog 34 is released and the spring 40 drives the dog round, and no credit is created until the credit cam is set forward sufficiently to wipe off the arrears, the pointer 43 then resting against its zero stop 45. In order to adjust the fixed charge, the pinion 15 is moved towards or away from the sector 10, and for this purpose the pinion is carried in a bracket 14 on a rotatable wheel 12 which can be rotated by a pinion (not shown) driven by a hand knob. The wheel 12 is kept in any set position by a spring 50 and drives a pointer 49 moving over a scale 48 graduated to show the weekly or fixed charge. In order to ensure the teeth of the sector 10 meshing properly with the pinion teeth, a star-wheel 17 is fixed to the pinion and is engaged by a spring-loaded roller 16 so that the pinion teeth are always in the correct position to mesh with the sector as the latter moves into engagement. In a modification, the pinion 15 is mounted on a fixed axis and the fixed-charge adjustment is made by adjusting the sector 10 angularly on the driving wheel 9. A two-speed gear 27, adjusted by a handlever 55, is provided to give a different range of adjustments for the fixed charge; the two ranges being shown on the dial 48. The handlever 55 has a free position in which neither gear 25 or 26 is in mesh, and this enables the collector to rim off the arrears when desired.