Patent GB-692988-A (GB)
Title: Attachment for producing geometrical profiles on work pieces in a machine tool
IPC: B23Q27/00
Filed: 1952-03-31
Abstract: 692,988. Copy-milling. DECKEL, H., and DECKEL, F. W. March 31, 1952 [Oct. 31, 1951], No. 8129/52. Class 83 (iii). A copy-milling machine having a tool carrier 12 freely movable in three directions by parallelogram linkage 14 and guided by slides and links (not shown), is modified for the cutting of geometrical forms, such as circles or ellipses, by the attachment to the tool carrier of a crank-plate 28 having a radially-adjustable crank-pin 52 which can be rigidly located relative to the frame 10 of the machine so that, on movement of the tool carrier by the handle 18, the plate 28 is constrained to rotate about the axis of the crankpin and impart the generating movement to the tool carrier. The parallelogram linkage 14 is hinged to and vertically movable on the frame 10 and the tool carrier is hinged to the linkage at 16. A bearing member 32, Fig. 4, for the bearing pin 30 of the crank-plate is pivoted in a bracket 38 secured to the tool carrier so that the crank-plate can be adjusted into a horizontal, vertical or intermediate position as indicated by a scale 44 and locked there by a clamp 48. The crank-pin 52 is carried by a slide 50 adjustable in the crank-plate relatively to the pin 30, being adjusted roughly by hand and then, for fine adjustment, connected by a clamp 88 to a screwed sleeve 82 on a spindle 84 having a knurled knob 87; a clamp bolt 74 locks this adjustment. An indexing-plate 98 with ratchet teeth engaged by a locking pin 100 enables the crank-plate to be indexed relative to the bearing member 32 and a stop-pin 110 can be moved into the path of a pair of stops 108 on the crankplate to limit the latter's rotation. A lever 112 operates both pins 100, 110. Operation. To cut a circular shape in work 126, Fig. 1, the crank-plate is set in the vertical plane, the slide 50 adjusted radially so that the eccentricity of the crank-pin corresponds to the radius of the circular shape and the axis of the crank-pin is then rigidly located relative to the machine frame by placing over its bearing 56 a universal coupling 58, 60 which is vertically adjustable in a slide 64 carried by the frame and is locked by clamps 68, 70. With the lever 112 in mid-position so that both pins 100, 110 are withdrawn, or in the upper position, so that the stops 108 limit its rotation, movement of the handle 18 causes the plate to rotate about the crank-pin 52 and move the tool-carrier in a circular path. For machining a second workpiece 120, another tool 122 can be placed in the tracer socket and driven from the first tool. If the clamp bolt 74 is released so that the crankplate is free to move relative to the fixed crankpin within the limits of stops 140 and rotation of the plate is prevented by depressing the lever 112 to engage the indexing stop-pin 100, the tool carrier will be given a rectilinear movement at the angle to which the plate is indexed and bevels may be cut on the work. By pivoting the crank-plate into the horizontal position, Fig. 7, circular shapes in the side of work may be cut and in any intermediate position elliptical shapes may be cut.