| 摘要 |
1,141,478. Boring and facing heads. J. A. SCHOLL. 8 Nov., 1966 [8 Aug., 1966], No. 49971/66. Heading B3C. A boring and facing head 10, Figs. 1 and 4, comprises a tool carriage 18, movable transversely of the axis of the head by a gear train which includes a detent device, the feed and retraction of the carriage being automatic. Carriage 18 has adjustable stops 28, 30, which co-operate with a pin 32, to limit its feed and retraction. A non-rotary screw 31 is carried by the carriage and co-operates with a nut, having external teeth 36 which mesh with a worm 38. A spur gear 42 integral with the worm meshes with a gear 44 formed on a shaft 46, the latter having a star wheel 50 at one end, which can engage with any one of a plurality of retractable pins 52 mounted in the periphery of a rotatable ring 54, so as to rotate the star wheel, and move carriage 18 radially. Ring 54 has a lever 56 for retracting the pins 52, and a recess 58, into which a pivotable pin 75 carried by a second ring 70 can drop, ring 70 having a torque rod 120 which engages fixed posts 118. In operation, drive shaft 112 is rotated, ring 70 is stationary with rod 120 held against a post 118, pin 75 sits on the top face of ring 54, and the ring rotates part of one revolution with the body 12 of the head. Recess 58 in ring 54 reaches pin 75, the pin pivots, and the rotation of the ring is stopped. The pins 52 engage the lobes of star wheel 50 as each lobe passes a pin, and the gear drive is rotated to feed the carriage 18, until stop 28 abuts pin 32. The gear train is looked, and the carriage 18 and body 12 rotate together until the star wheel encounters the next pin 52, whereupon ring 54 is caused to rotate with body 12, and pin 75 is tilted out of recess 58. In order to retract the carriage, the direction of rotation of drive shaft 112 is reversed, and no manual manipulation of shaft 40 is required. Various arrangements of pins 75 are described. |
