Patent GB-1002986-A (GB)
Title: Improvements in indicating maximum demand meter
IPC: F16H19/00
Filed: 1961-11-21
Abstract: 1,002,986. Counters. GENERAL ELECTRIC CO. Nov. 21, 1961 [Nov. 23, 1960 (2)], No. 41606/61 Heading G4D. [Also in Divisions F2 and G1] A maximum demand meter has one or more indicators coupled to the drive by a clutch which only allows the indicators to be engaged by the drive after the drive has been driven through a count equal to that retained on the indicators, which is the maximum quantity counted in any previous interval of, say, 15 minutes in the current period of, say, one month. In one embodiment, Figs. 1 and 4, 7, 8 a pin 70 on disc 66 engages a dog 72 to drive the unit pointer 40. Similar couplings, 92, 88 and 94, 90 are provided for the tens and hundreds pointers respectively although the operative drive for these pointers comes through gearing 86 from the shaft of the unit pointer 40. After each 15 minute interval an automatic timing mechanism 108 raises member 112 which engages a cam 126 and causes member 76 carrying dog 72 and members 88, 90 to pivot and thus disengage the coupling between members 72, 88, 90 and pins 70, 92, 94. The timing mechanism also causes the drive to the gears 68, 100, 102 driving pins 70, 92, 94 to be disconnected therefrom and the pins are returned to zero position by phased gearing such as wedge-shaped racks like 138 on member 112 engaging helical gears like 132 on the shafts driving pins 70, 92, 94. The member 112 is then lowered causing the drive to be reconnected to gears 68, 100, 102. However until pin 94 which is longer than pins 92, 72, has been driven through a sufficient count for it to mate with the aperture in member 90, pins 92, 70 are held out of engagement with members 88, 72 and the indicator is not driven. Similarly pin 92 is longer than pin 70 and no drive is transmitted to the indicator pointer until the drive has been driven through a count equal to that retained on the indicator. The indicators are returned to zero at monthly intervals by similar zeroizing mechanism. In an alternative embodiment, Fig. 17, of the cyclometer type, the hundreds 222, tens 220 and units 218 driving wheels are geared together and are connected to indicator wheels 216, 214, 212 by means of pins 266, 264, 262 which engage apertures in the indicator wheels. At the end of each time interval the indicators, which are mounted on a shaft 258 are separated from the driving wheels by rotation of a cam 256. The driving wheels such as 222, Fig. 20, are disconnected from the driving gear 252 by rotation of an eccentric 300. The driving wheels are returned to zero by means of an eccentric 292, Fig. 19, and a heart-shaped cam 284. The cam 256 is then rotated to its original position and the shaft 258 is urged by spring 268 to its original position. However, pins 266, which are longer than pins 264, 262 prevent engagement between the tens and units driving and indicator wheels until the hundreds driving wheel has been driven sufficiently to allow pins 266 to enter the apertures in wheel 216. Similarly pins 264 are longer than pins 262 and thus the indicator wheels are not driven until the drive has been driven to a count equal to that on the indicator wheels. Means are provided to prevent the indicator wheels being returned to zero with the driving wheels. The indicator may be set to zero at the end of a series of test intervals by knob 310.