GB1504958A - Counter structure - Google Patents

Abstract

1504958 Counters SUN OIL OF PENNSYLVANIA 18 June 1975 [17 July 1974] 25921/75 Heading G4D In a counter such as that described in U.S.A. Specification 2,814,444 an arm 20 supported by but not rotatable about the shaft of the number wheels carries buttons 26, e.g. of nylon, which frictionally engage the driven gear 12 of the lowest order number wheel to prevent overrunning when the drive is stopped. The counter is employed in a petrol dispenser; with increasing prices it is necessary to reduce the speed of the counter by a factor of 10 and give the lowest wheel 100 graduations so as to increase the total price displayed; the braking action of the buttons 26 ensures accuracy of the display. The Specification also describes a more accurate resetting mechanism for the counter. The counter wheel comprises a numeral drum 30 attached to a hub 23 upon which is loosely mounted the driving gear 12. The gear 12 has an annular indented portion 31 bearing teeth 39 which in the counting condition co-operate with a coupling blade 33 which is pivoted in a slot in the hub 23 so the gear and drum rotate as one. For resetting the shaft is moved axially so that a part 41 of the blade 33 is forced out of an annular groove in the shaft and disengages the drum from the gear. At the same time another blade similarly mounted is forced out of the groove and a allows a spring driven plunger 45 to couple the drum to a resetting gear 52 whereby the drum is driven back towards zero. At the zero position the blade 36 drops back into a longitudinal slot 53 in the shaft 11 to disengage the drive. To increase the accuracy of the zero position the blade 33 has an arm 38 which in the resetting position is axially aligned with a latch 54 pivoted to fixed part of the structure adjacent the rim of the drum 30; in the zero position the latch 54 snaps into engagement with the arm 38 to accurately determine the zero position. If the drum is at 1 or 99 when resetting the blade 36 can drop prematurely into an oversized or worn slot 53 so that no resetting drive occurs. To prevent this latch 54 has an arm 67 which when the latch is displaced by arm 38 pivots a linkage 65-69-71 which pushes the blade 36 out of the slot 53 until the drum is properly reset.