| 摘要 |
620,853. Chucks. DEARBORN, J. W. Nov. 8, 1946, No. 33239. Convention date, May 1. [Class 83 (iii)] A work-holder and indexing device comprises an indexing head 56, a chuck 71 in the head, and an indexing arm 142 which has an eccentric face 166 at one end and is pivotally supported by a member 141 carried by the head so that pivotal movement of the arm moves the eccentric face into frictional engagement with the head and rotates it in the direction of movement of the arm. The chuck collet 72 is closed by springs 93 acting on a ring 82, and is opened by upward movement of lugs 181 against the ring 82. The lugs 181 are formed on a horseshoe member 175, pivoted at 179, which is supported at the opposite end by a lever 185 pivoted on a second lever 43 carried on a shaft 41 which is turned to open the collet by a manually- or automatically-operated chain 191. As the shaft 41 is rotated, a further lever arm 192 mounted thereon is turned to engage a pawl 208 with a bell-crank 214 pivoted at 211 which raises an ejector 118 detachably mounted on the end of the bell-crank. The latter is returned by a spring-plunger 213. Indexing.-The head 56 carrying the collet is engaged by yoke arms 143, 144 and a tongue 150 of the member 141. The handle 142 pivoted at 169 is constrained between a spring- pressed plunger 173 and an adjustable stop 1710. Clockwise rotation of the handle indexes the head, and reverse rotation releases the eccentric 166 and the stop 173 engages the member 141 to return it. Two scales are provided on a base 22 for adjusting a stop 28 coacting with the upper scale and engaging a fixed stop 153 on the member 141 for angles up to 90 degrees and a stop 32 coacting with the lower scale and carrying a lug 36 to engage a plunger 156 for angles between 90 and 180 degrees. In the latter case, the plunger 156 is depressed on a second swing of the handle. The head 56 is held in adjusted position by brake-shoes 127 which are pressed against the holder by levers 129 pivoted at 130 and forced apart by a spring 140. The holder may be rotated by a pawl 163, shown disengaged in Fig. 1, engaging teeth 70. |
