GB283393A - Improvements in and relating to copying-lathes - Google Patents

Abstract

283,393. Duchemin, G. W. May 5, 1927. Lathes.-A lathe for turning irregular forms such as boot lasts comprises a swinging frame 11 pivoted on bearings 12, 13 to the support 10 and provided with a sliding chucksupporting frame 20 carrying the chucks 19 for holding a number of work pieces 23 which are shaped from a single pattern 54 having independent movement controlled by length grading mechanism. The work and pattern are held up to the tools 48 and tracer wheel 77 respectively by means of a weight 18. The chucks are driven from an electric motor 41 mounted on the chuck support 20 and connected through belt gearing 40, shaft 39, worm gearing 38, reversing bevel gearing 32, 33, shaft 31, belt gearing 29, and spur gearing 26, 25, to the shafts 24 driving the work chucks. The shaft 31 has a screwed portion engaging a nut on the chuck frame 20 and the reversing gearing is arranged so that a slow working movement and a quick return are imparted to the chuck frame. The reversing-gear is actuated from a handle 35 which may be moved either by hand or automatically by means of stop collars 45 mounted on a rod 46 in the path of a rear extension 47 of the handle 35 which moves with the frame 20. The cutter spindles are driven from an electric motor 53 through belts 51. The pattern 54, preferably of metal, is mounted in a chuck 55 slidable on bars 56 and is rotated through a yoke-shaped extension of the gear 26 by means of a connector 57 sliding in a groove in the yoke. Longitudinal movement is imparted to the pattern through a rod 63 connected to a transverse bar 66 which receives its movement from a pair of links 68 pivoted to a fixed bar 76 and connected to the bar 66 by pins and blocks 69. The links are swung about the pivot 67 by means of pins secured to the chuck frame 20. The blocks 69 may be moved along the arm 66 by means of a screw 74 to vary the length of the work relative to the pattern, this adjustment being facilitated by a scale 81. Width grading is regulated by adjusting the pattern to and from the pivot of the frame 11 by means of the rod 27, an indicating scale 78 being provided on the rod 80 along which the tracer wheel 77 is corres. pondingly adjusted. In a modification, Fig. 10, the workpieces 23 and the pattern 54 are mounted on opposite sides of the pivotal axis of the frame 11 and the work and pattern are moved in opposite directions by means of a pivoted arm 82 connected by links 84, 85 to the work frame and pattern respectively. Length grading is effected by varying the points of connection of the links 84, 85 to the arm 82.