| 摘要 |
764,593. Chucks. ELECTRIC & MUSICAL INDUSTRIES, Ltd. Nov. 19, 1954 [Dec. 1, 1953], No. 33300/53. Class 83 (3). [Also in Group XXIII] A chuck for holding circular or non-circular work, particularly for glass-working lathes, comprises more than two jaws, means for guiding the jaws radially, and operating-mechanism including a pair of rotary members and driving mechanism common to both the rotary members, rotation of the latter causing simultaneous movement of the jaws and continued movement of one or more jaws after one of the other jaws has been arrested by engaging the work. A circular-base member 1, Fig. 2, has an annular recess 5 into which fits three concentric rings 6-8. A cover-plate 9 encloses the rings and supports four slides 10 having jaws 11-14 respectively clamped thereto. The slides are spaced 90 degrees apart and are constrained by guides 10a to move radially. The middle-ring 7 has, attached to its underside, an arc-shaped rack 23 which engages a pinion 24 actuated by a wheel 26. The three rings are connected by levers 20, Fig. 1, which permit limited relative angular movement. The inner ring 8 has opposite cam-grooves 17, 18 which engage pins 21 extending below the jaw-slides 10 for the jaws 12, 14; similarly the outer ring has cam grooves controlling the jaws 11, 13. On rotation of the wheel 26 to close the jaws, one pair of jaws makes contact with the work and the rings then move relatively until the other pair of jaws makes contact, the levers 20 rocking on the ring 7. Preliminary adjustment of the jaws is made on the slides 10 so that they are set open slightly greater than the two major dimensions of the work, such as'a rectangular bulb for a cathode-ray tube. The hub 3 of the chuck may be formed as a vacuum chamber 4 for temporarily or partially holding the work during centring. |
