Patent GB-529710-A (GB)
Title: Improvements in or connected with coin freed mechanism for meters
IPC: G07F15/08
Filed: 1939-02-24
Abstract: 529,710. Prepayment mechanism for meters. GLOVER & CO., Ltd., T., and KLEIN, J. F. Feb. 24, 1939, Nos. 6170 and 21563. [Class 27] Coin-freed mechanism for two-part-tariff meters comprises a sliding-clutch two-speed gear between the meter-driven shaft and the worm of the quantity mechanism, a second sliding clutch geared to an adjustable setting cam wheel acting through a setting plate on both clutches whereby (1) the gear ratio is automatically changed from high to low tariff after the worm has made a predetermined number of revolutions and (2) the second clutch is disengaged to allow the setting wheel to return to zero, means being provided for re-setting the gear to the high tariff position by hand, such as by the cash drawer, or at fixed time intervals as by a clock. In the construction shown the gas valve 3 is opened by rotation of the coin knob 56 and shaft 4 which screws into the usual sliding circular rack 1 meshing with a toothed quadrant on the valve arm. The valve is closed by the meter-driven shaft 10 acting through a two-speed gear on a worm 19 gearing with a worm-wheel 9 splined with the slidable rack 1, so that as the rack 1 rotates on the normally-stationary screw 4a of the shaft 4 the rack slides axially in the valve-closing direction. In the normal or hightariff position shown in Fig. 4 the shaft 10 drives the worm 19 at the same rate through gears 13, 22 and 23, 20, but when a sliding clutch 28 is moved to the left to disengage it from the gear 23 and engage the clutch part 26 of a gear 27, the shaft 10 drives the worm 19 at a slower rate through the gear 13, 22 and 27, 18. The gear ratio is changed automatically after a predetermined number of revolutions of the shaft 10 by means of a sliding plate 46 having a pin 48 engaging the clutch 28, and for this purpose the worm 19 meshes with another worm wheel 45 on shaft 44 having a worm 43 driving a wheel 42 fixed on a shaft 29 and adapted to be coupled by a slidable spring-loaded clutch 40 to a gear 30 loose on the shaft. The clutch 40 is controlled by a second pin 47 on the sliding plate 46. The gear 30 is in mesh with a gear 34, Fig. 5, having a slot 36 engaged by an adjustable pin 37 inserted in any one of a number of holes 38 in a fixed plate, a spring 39 constantly urging the gear 34 in one direction. Thus, when the clutch 40 is disengaged from and frees the gear 30 the latter is always re-set to its zero position as determined by the pin 37. When a coin has been inserted and the meter shaft 10 starts to drive the worm 19 at the high-tariff rate the gear wheel 30 is also rotated until a cam 33 thereon, Fig. 8, engages a pin 51 on a lever 50 and rocks the latter clockwise as seen in Fig. 6. The lever 50 bears against pin 47 on the slide 46 and accordingly moves the slide to operate the clutches 28 and 40 and change the gear to the second ratio or low tariff. As the clutch 40 is now disengaged the gear 30 flies back to its zero position in readiness for the next high-tariff period. A spring-loaded arm 52 bears on the upper #-shaped edge of lever 50 and gives a snap action thereto in changing from one gear ratio to the other. An indicating sector 62 showing whether the gear is in the high-tariff or lowtariff position is operated by the slide 46. Instead of using a pin 37 and holes 38 to determine the zero position of the gear 30 a fine adjustment may be obtained by worm and wheel gear. The gear ratio may be changed back to the high-tariff position by hand, by the collector or automatically by a clock device after a fixed period, or by the withdrawal of the coin box. In the construction shown in Fig. 10 the slide 46 is moved to change the gear ratio by means of a lever 72 controlled by a clock 65 having a disc 67 which is allowed to rotate one revolution when a trip lever is rocked, say, once a week. A pin 68 on the disc is normally in the position shown at 8 o'clock on a clock dial, and thus lies below the shorter of two prongs 72a, 72b on the lower end of lever 72 so that the lever is free to move from the high-tariff position shown in full lines to the low-tariff position shown in broken lines. When the disc 67 is released at the end of a time period, the lever 72 is in the low-tariff position the pin 68 enters between the prongs and moves the lever and the slide 46 back to the high-tariff position. If the consumer has not used sufficient gas to cause the slide to. be moved to the low-tariff position the pin 68 rocks the lever 72 from the high-tariff position to the low-tariff, and back again to the high-tariff. The first movement disconnects the clutch 40 thus re-setting the gear 30 to zero position, so that the full pre-determined number of revolutions of the meter shaft 10 is necessary in the new time period before the gear is changed from high-tariff to low-tariff. In the construction shown in Fig. 12 the slide 46 and lever 72 (not shown) are operated by a coin drawer 76 having a cam plate 78 adapted to operate the lower end 72c of the lever 72. Thus, when the drawer is withdrawn the lever 72, if it is in the low-tariff position, is unaffected, but if it is in the high-tariff position it is moved to the lowtariff position, and when the drawer is pushed in again the lever is moved back by the cam to the high-tariff position.