| 摘要 |
1,062,549. Copy-milling. CINCINNATI MILLING MACHINE CO. Sept. 24, 1965 [Nov. 2, 1964], No. 40864/65. Headings B3K and B3T. A machine tool comprises a fixture 11 for supporting a work blank by one end thereof and rotating it on a fixed axis, a cutting tool 20 relatively movable along the blank and movable to-and-from the blank, and a work-support mechanism 26 comprising a platform 27 having a central opening for receiving the work, means for supporting the platform for free rotation on the axis and for moving it towards the fixture ahead of the tool, gripping means 39. 40, 44, 45 on the platform for engaging the work, and release means 60, 61 for momentarily relaxing the engagement of the gripping means in timed relation with rotation of the work and platform. A number of cutters 20 are carried on a bracket 18 which can be swung towards the workpieces 12 arranged in line and rotated by an hydraulic motor. The cutter movements are controlled by a single hydraulic timer means or by a programme on cards or tape. The bracket 18 and the work-support 26 are carried by a slide 17 traversed downwardly at a slow feed rate. Each blade is surrounded by a plate 27 supporting a plunger 47 carrying a pivoted bracket 37 having the work-engaging members 39, 40 and a plunger 41 carrying a fixed bracket 42 having the work-engaging members 44, 45. The plungers 36, 41 are urged towards the work by springs such as 48, Fig. 5 (not shown), to backup the work against cutting forces, and are prevented from return movement by wedge pins 51 engaging oppositely-urged plungers 52, 57. Relief of gripping pressure.-The plungers 52, 57 are moved inwardly every 180 degrees of movement of the blade, to relieve the wedging force, by the plungers 60, 61 operated hydraulically under the control of dogs 65, 66 and a switch 63. Since the gripping means are forcibly moved down over the blade towards its thickest portion as the cutting proceeds, the relieving action is necessary to avoid undue pressure of the gripping means on the work. Scoring marks made by the grippers are removed as the cutter follows up. For setting- up purposes, the plungers 36, 52 and 41, 57 can be retracted by crank handles 70, 80. |
