GB735443A - Improvements in or relating to counting devices - Google Patents

Abstract

735,443. Counting-apparatus; zeroizing mechanism. ENGLISH NUMBERING MACHINES, Ltd. Sept. 2, 1953 [Sept. 2, 1952], No. 22058/52. Class 106 (1). [Also in Group XXIV] A composite member in a counter is rotatable as a unit and comprises two relativelyrotatable parts one of which is made of a plastic material and is so shaped that at least one integral and inherentlyresilient pawl is formed for co-operating with a recess or recesses in the other part. A number wheel, Fig. 1, has an outer part 24 formed with ratchet teeth 25 which are engaged by pawls 21 -integral with an inner part 20. The outer part has teeth 28 by which it is driven and transfer teeth 30 while the inner part is formed with a re-setting cam 29. Driving teeth may alternatively or additionally be carried by the inner part. The inner part is formed by moulding or machining a plastic such as a self-lubricating polyamide. The outer part may be similarly formed or it may be of cast or machined metal. The pawls may alternatively be formed with the outer part. The arrangement allows the number wheels to be re-set to a pre-set number. In a different arrangement, Fig. 4, a units number wheel 124 has ratchet teeth engaged by pawls 121 formed integrally with an inner part 120 fast on a driving shaft and by non- return pawls 155 integral with a fixed disc 154. The counter may thus be advanced by rotation or oscillation of the driving shaft. In a further arrangement, Figs. 6 and 9, a counter is actuated by rocking a shaft 282 which is then restored by a spring 287. Ratchets fast with a gear 289 co-operate with ratchettoothed sleeves 292 and 293, fixed and non- rotatable relative to the shaft 282 respectively, under the action of a spring 296. The gear 289 is thus advanced in one direction at each oscillation of the shaft 282. Geared to the gear 289 is an inner part 220 with integral pawls 221 engaging ratchet teeth in an outer part 224 fast with the units number wheel 280. Integral with the wheel 280 and with each of the higher order wheels, which are of plastic material, is an inherently resilient pawl 299 which co-operates for zeroizing with a longitudinal notch in the shaft 223 on which the wheels are rotatable. Zeroizing is effected by rotation of a knob 301 fast on this shaft.