Patent GB-818152-A (GB)
Title: Improvements in or relating to machines for determining the unbalance in rotating bodies and for correcting the unbalance
IPC: G01M1/30
Filed: 1955-10-13
Abstract: 818,152. Welding by pressure; shearing. GISHOLT MACHINE CO. Oct. 13, 1955 [July 22, 1955], No. 29196/55. Class 83 (4). [Also in Groups XIX and XXXVIII] In an automatic multiple-station balancing- machine adapted to measure the unbalance in successive like rotary workpieces 13 and to correct therefor (see Group XXXVIII) the correction is applied by welding to the workpiece a mass 24 which has been previously cut from a reel of strip 22 to length determined by the measured unbalance. The unbalance measurement causes a motor 182 to rotate to an extent determined by the unbalance. On the shaft of motor 182 is a cam disc 186, Fig. 22, the position of which controls the amount of strip 22 which is fed through a shear 204, Fig. 20. The strip 22 is fed from a reel through a set of straightening rolls 174 and then through spring-pressed feed rolls 175 which are driven by a feed motor 187 (not shown) through reduction gearing and a clutch 179. The motor 187 is provided with a brake 188 (not shown) and it also drives a gear 195 which moves a rack 194 longitudinally. The rack carries with it a control carriage 197 which has mounted on it a pivoted lever 198 which is biased by a spring 200 and is moved by the rack 194 into engagement with the cam 186 on the shaft of the motor 182. When the lever engages the cam 186 it yields and operates a limit switch 201 on carriage 197 the switch 201 through relays applying a brake 188 to stop rotation of the motor 187 and hence the feed of the strip 22. The correction mass 24 is sheared from the strip 22 by a shear punch 207, which is carried by a pivotal lever 209 actuated by a toggle link 210 and lever 211. A push-rod 212 at the end of lever 212 is actuated through a bell-crank 213 and push-rod 215 from a cam 218 on a shaft 40. The time of starting of the motor 187 is determined by a contact drum 157, Fig. 30, which is driven from the shaft 40 and after the shearing of the correction mass has been completed the contact drum causes the motor 187 to be reversed to return to its original position, where it is stopped by a limit switch 203. The clutch 179 prevents reverse drive of the feed rolls 175. If the unbalance in the workpiece is less than half the minimum strip length it is arranged that strip stock 22 is fed to the shear 204; if the amount of strip required for the correction mass is greater than the maximum amount the cam 186 is designed to measure, a limit switch comes into operation and stops the motor 182 at the maximum amount. The mass 24 is moved from the shear 204 into the welding position by means of a feeder wheel 223, Fig. 30. When the rolls 175 move the strip 22 forwardly into the shear 204 the part to be cut-off to form the correction mass is moved into one of four transfer heads 222 on the wheel 223. The wheel 223 is intermittently rotated by the motor which drives the cam-shaft 40 so that the correction mass for a given workpiece reaches the welding apparatus at the same time as the workpiece. The mass 24 is transferred from the head 222 to a carrier 208, Fig. 25, by means of a poker 227 which is moved in synchronism with the wheel 223. When the mass is in the carrier 208 it is positioned between the welding tongs 225 of the welding apparatus, these being pivotally carried by a bracket 246, Fig. 26, on a carriage 247 which reciprocates between a position where the carrier receives the correction mass from the head 222 and a position in which the mass is held against the lower surface of a blade 25 of the workpiece. The carriage is moved by means of a rack 250 and a gear segment 251 which is actuated through linkage by a cam 258 on the shaft 40. When the correction mass is located against the lower surface of the blade 25, the welding apparatus is put into operation by timing contacts on the drum 157. The welding carriage after welding is completed, is then moved back to its original position by the cam 258.