GB572865A - Improvements in or relating to counters - Google Patents

Abstract

572,865. Counting-apparatus. STEVENS, A. H. (Veecler-Root, Inc.). Aug. 9, 1943, No. 12835. [Class 106 (i)] A counter is provided with overthrow-preventing means for the lowest order wheel during a counting operation by positively limiting it to a step-bystep advancement. The counter includes a ratchet wheel with square-cut notches connected to the said wheel, an oscillatory pawl to drive the ratchet wheel, and means for releasing the pawl after each oscillation in the driving direction. As shown in Figs. 2, 3, 4 and 6, the numeral wheels 12 of the counting unit are rotatably mounted on a reset shaft 14 journalled in a casing 10. A second shaft 16, also journalled in the casing, is connected by a linkage to the mechanism, the operations of which are to be counted and is thereby oscillated to operate a ratchet drive means 18. This drive means includes a hub 58 rotatable on the shaft 14 and formed with lugs 60 extending into recesses 62 in the adjacent face of the units wheel. Integral with the hub is a ratchet wheel 64 with square-cut teeth ; adjacent the ratchet wheel 64 is a second ratchet wheel 70 loose on the hub and formed with spaced triangular teeth. A spring-controlled driving pawl 78, with a square-cut tooth straddling both the ratchet wheels, is pivoted on an arm 80 connected by a toggle link 86 to an arm 88 fixed to the drive shaft 16. A detent pawl 92 co-operates with the ratchet wheels to prevent backward movement. By this arrangement if the ratchet wheel 64 tends to over-throw, it is retained by the trailing edge of the tooth engaging the rear edge of the tooth of the pawl. On the reverse movement, the ratchet wheel 64 will be returned to align the teeth of the ratchet wheels and the driving pawl will ride up and be released. To eliminate fine adjustment in the drive linkage, the arm 88 is formed with spaced stops 100, 102 to co-operate with a projection 106 on the base of the casing. The numeral wheels are preferably made of plastic material and as shown in Figs. 9, 10 and 11, each comprises a member 103 and a driving member 128. The member 103 has a hub 105, a flange 108, and a recess 118 to receive a reset pawl 124, and the driving member 128 includes a gear 130, a disc portion 132 with parallel guideways 134 in .each of which is located a spring-controlled driving pawl 138 to establish connection in one or other direction of rotation between the member 128 and teeth 143 on the inner face of the flange 108 of the member 103. A dividing disc 142 maintains the reset pawl 124 in its recess 118. The member 103 is also formed with a locking shoulder 110 and a twotoothed portion 114 to co-operate with the usual transfer pinions 144 for carry-over purposes.