Patent GB-381996-A (GB)
Title: Improvements in prepayment electric meters
IPC: H02K27/04
Filed: 1931-08-07
Abstract: 381,996. Prepayment electricity supply meters. SIEMENSSCHUCKERTWERKE AKT.-GES., Siemensstadt, Berlin, and HORNBY & CO., Ltd., R., 7, Carlisle Street, Soho, London. Aug. 7, 1931, No. 22418. Convention date, May 1. [Class 37.] In a prepayment electricity meter having a meter-driven gear-change device for altering the tariff after a predetermined consumption, this consumption is adjusted by means of a member, e.g. 332, ' outside the main meter enclosure and itself enclosed in a sealable member. The meter disc 10 drives the wheel 50 of the coin mechanism through gearing 11, shaft 12 and either gears 41, 42, 47, 48, or ratchet gear 43, 440, 44 and gears 45 .. 48, the ratchet gear being overrun when the wheel 50 is being rotated at the higher speed through gears 41, 42. The meter disc also drives the predetermined consumption controlling mechanism, through gears 13, shaft 14 and gears 392, 391, 36, the gear 392 being disengageable from the gear 391 by means of a spring-biased lever 37 which also disengages the gears 41, 42 at the same time. A spring- returned disc 31, loosely mounted on a spindle 310 and geared to the gear 36 has a pin 34 on its upper face and a pin 32 on its lower face, the pin 32 contacting with a starting position stop 33 on a gear disc 330 so that the initial position of the disc 31 is set by the position of the disc 330 which can be adjusted through gearing 331 by a graduated knob 333 situated outside the meter casing. The pin 34 on the disc 31 is adapted to contact with, and turn, a spring-controlled lever 340 after a predetermined rotation of the disc 31 as set by the position of the disc 330 when an arm of the lever 340, engaging a stop 343 on the lever 37, turns the lever 37 and disengages the gears 41, 42 and 391, 392, after the consumption of a predetermined amount of energy. The disc 31 now rotates back to the starting position, but the lever 340 is held by a spring-controlled detent 21 engaging a notch 3420 in the lever 340. The detent 21 is released and the lever 340 reset by a push rod 23 which moves the detent 21 and the knob 22 of' which is sealed by a sealing loop 220, outside the meter casing. A member 24 functions as a bracket for the push rod 23 and a stop for the lever 37. In a modification, Fig. 2, the disc 31 is driven from the meter through a slipping clutch 393 and also rotates a scale 26 through gearing 28, 27, the scale 26 being provided with a pointer 260 which also functions as a brake. In this case indication of the amount of energy consumed at the higher rate is given by the scale 26. The lever 340 (not shown), detent 21 (not shown), and disc 31 are reset by a push rod 23, which resets the levers and engages a gear 230 with a gear 25 on the scale 26. Rotation of the push knob 22 now resets the disc 31, and a slipping clutch drive 235, on the push rod 33, prevents over rotation. A pawl and ratchet 231 on the push rod 33 prevents rotation in the wrong direction and a pin 234 on the rod 23 fits a slot 233 in a bushing 232 so that connection between the gears 230, 25 cannot be released until one or more complete rotations of the knob 22 have been made.