GB811341A - Gear checking apparatus - Google Patents

Abstract

811,341. Electric indicating systems. NATIONAL BROACH & MACHINE CO. May 1, 1956 [June 6, 1955], No. 13344/56. Class 40 (1). The dimensions of gear teeth are checked by means of a pair of independently movable sensing devices which engage simultaneously with two tooth surfaces of the gear and which are moved in a direction substantially parallel to the gear axis. As shown, the gear 80, the teeth of which are to be examined in succession, is clamped on the end of a work spindle 86 by a nut which engages on an interrupted thread. The spindle 86 is carried in sleeve 88 which is mounted in support 90. The sensing device 34 (v.i.) is carried on the cross-slide 72, itself supported on an intermediate longitudinal slide 28 and a main slide 24. The intermediate slide is adjusted longitudinally on the main slide. The main slide is then reciprocated longitudinally by means of a motor 36 which drives shaft 42, gearing 44, 46 and an adjustable throw crank mechanism 50, 58 to reciprocate the main slide through connecting lever 62. The head carrying the sensing device is moved radially with respect to the gear by a cam 70 sliding on a splined portion of shaft 42 and moving the slide by contact with the end of adjustment screw 72 against the action of spring 76. Thus, during the feed of the main slide the transverse slide is so positioned that the tooth under examination is gauged but is withdrawn at the end of the gauging stroke. The gear is moved around tooth by tooth by a lever 130 racked by a cam 132 on the shaft 42. The cam breaks a toggle 110, 112 against the action of a spring 122 and through a pawl 124 engaging in an indexing plate on the end of shaft 86 rocks the work shaft to index the gear one tooth. At the same time pawl 128 carried on an extension of sleeve 88 is forced out of engagement with the indexing plate. As lever 130 moves back locking pawl 128 drops into its recess holding the shaft 84 while the feed pawl rides out of its slot over the edge of the indexing plate and drops into the next one. The sensing device consists of feelers 190, 192 engaging the upper and lower side respectively of the tooth being engaged and so pivoted at 194 that their rear ends adjust cores in transformers 196. Recording mechanism.-As the slide 25 advances during a gauging stroke it pulls a tape 174 tensioned by a weight 186 over a roller 172 to drive a record chart 10 through shaft 170 and one-way clutch 171. The one-way clutch prevents movement of the chart during the return stroke of the slide. A pair of pens are moved each in accordance with the output of one of the sensing devices. A plot of the type shown in Fig. 1 is produced on the chart. Gauging helical teeth (Fig. 3).-A helical slot in a member carried on the sleeve 88 is engaged by a follower 216 carried by slide 25. Thus the sleeve is rocked during gauging and through pawl 128 similarly rocks the gear as the sensing fingers move horizontally.