| 摘要 |
1,090,482. Copy-milling. PRECISION HYDRAULICS Ltd. April 12, 1966 [April 24, 1965; Oct. 30, 1965], Nos. 17381/65 and 46021/65. HeadingB3K. Tracing. apparatus comprises a feeler 9 to engage a shaped member 1 on a platform 2, means 18 for moving the feeler within a carrying head to tend to maintain it against the member, and second means 3, 4 for moving the platform or head to follow the shaped member, the second means being controlled by the movement of the feeler in the head. The platform is mounted on superposed slides movable by the fluid-operated devices 3, 4. The feeler is supported by a ball-joint 11, 12 and is engaged at its upper end by the spring- pressed plunger 18 in carrier 7, 16 rotatable in bearings 15. A disc valve 28 is free to move in a horizontal plane as the feeler is rocked and co-operates with axial ports 25, 26 spaced 90 degrees apart and a radial port 24. When the valve is displaced from a central position, edges 31 uncover ports 25, 26 and either allow fluid to pass from the port 24 to the ports 25; 26 and so to the fluid-pressure devices 3, 4 or cause exhaust flow from the devices 3, 4 via a chamber 36 and a passage 49. Angular movement of the feeler, and thus the maximum platform speed, is limited by a conical recess in the threaded carrier part 16 which is adjustable axially by rotating it by a handle (39). By means of handles (44), the upper carrier part 7 is rotated to cause the bias plunger 18 to hold the tracer against the template. If a reentrant corner is encountered on the template, the plunger 18 is moved back against its spring and the copying movements stop until the bias direction is readjusted. In a modification, the slide valve 28, Fig. 4 (not shown), is limited in movement by a conically-recessed ring (61) adjusted by a collar (8) acting through rods (63). Movement of the valve (28) directs fluid to a swash-plate ball motor (54, 56) as well as to the slides and causes the direction of the bias plunger (18) to be adjusted automatically. A plunger (66) is engaged with one of two slots (67) in the carrier part (16) according to whether clockwise or anti-clockwise template-following is required. With the plunger (66) disengaged, the machine may be controlled manually. In further modification, the member I may be moved round the tracer. |
