| 摘要 |
1474515 Milling curved workpieces ALUMINUM CO OF AMERICA 22 Dec 1975 [15 Jan 1975] 52391/75 Headings B3K and B3B A machine for removing material from a workpiece such as a curved plate for use in the manufacture of spherical vessels and particularly the machining of the plate edges in preparation for welding comprises a workpiece (plate) support structure 14, 15 which mounts the curved workpiece 18 in a predetermined orientation with respect to and independent of the machining structure 24, a traversable head-stock 11 mounted on the structure and movable in an arcuate path on tracks 10a, 10b by way of a chain drive 26, the headstock incorporating a cross slide 32 and vertical slide 36 to permit the positioning of a milling cutter 12 mounted on the slide 36, the slider being actuated by way of screws 52, 54 respectively from independent motors 42, 41. The slide 32 is connected by way of a frame 53 to a sensing device 21 which engages a template 22 secured to track 10b to control the movement of the milling cutter 12 in a direction transverse to the plane of curvature of the tracks 10. A further sensor 20 is attached to the vertical slide 36 and engages the plate (workpiece) surfaces and is adapted to control the movement of the cutter slide 36 in relation to the actual curvature of the plate which may differ slightly from that of the tracks. The sensing means 20, 21 are linear variable differential transformers which control the motors 42, 41 for operation of the slides 31, 36. In an alternative embodiment a further sensor 81 is provided (see Fig. 10) which is used in co-operation with the sensor 20 to enable variations in the thickness of the plate to be monitored and maintain the rotory milling cutter 12 in a mean path. Although the cutting means described in the particular embodiment is a milling cutter other metal removing tools may be used such as an oxygen collimating orifice or a plasma arc cutting torch. |
