| 摘要 |
1,149,219. Copy milling; turret lathes; chucks. NATIONAL ACME CO. 16 Nov., 1966 [9 Feb., 1966], No. 51266/66. Headings B3B, B3K and B3T. Apparatus for milling an opening in a workpiece, e.g. a bayonet fitting slot, or more particularly a pair of such slots, in the end of a tubular workpieee, comprises work-holder means, a reciprocable support for a milling head having a milling cutter which is rotatable about an axis normal to that of the workpiece, cam means for causing the support to move towards the workpiece in the direction of its axis and means for causing arcuate movement of the head with its cutter relative to the workpiece. A workpieee comprising a tubular member 25 is held in a stationary spindle 24 of a multi-spindle lathe. The milling cutter 51 is disposed at right angles to the axis of the workpiece 25 in a milling head 40 which is angularly displaceably mounted in a support 32, 30, the support being displaceable towards and away from the workpiece by cam means 85. The milling cutter 51 is disposed across a recess in the head 40 which may be entered by the workpiece to allow simultaneous machining of two bayonet slots separated by 180 degrees, the cutter 51 being carried at one end by a collet 49 and at the other end by a pilot bush 52 and driven through bevel gears 45, 62 from a motor driven spindle 57. Arcuate movement of the milling head 40 is arranged to occur after longitudinal movement of the support and head have been effected i.e. after the axial part 144 of the bayonet slot has been machined, this arcuate movement being caused by cam means 123 which move a slide 134, the milling head 40 having a pin 142 which projects into an opening 139 associated with the slide 134. The longitudinal and arcuate movements of the head 40 are controlled by a template cam 73 having slotted portions 80, 81, 82 which guide a follower 69 mounted on the head 40. The cam 85 has a lost-motion connection with the support 30 comprising a spring member not shown, while a further spring member 118 is provided which co-operates with the cam 85 to effect movement of the follower 69 into the final recess portion 82 of the template cam 73 in order to effect the machining of the final or locking portion 146 of the bayonet slot. After the slots have been machined, reverse motion of the cams causes the cutter 51 and head 40 to return to the initial position free from the workpiece. |
