Patent GB-741102-A (GB)
Title: Improvements in or relating to machines for the manufacture of shoe lasts and similar bodies
Inventor: EKLUND CARL HJALMAR
IPC: B27M3/20
Filed: 1953-04-10
Abstract: 741,102. Copying-turning; making shoe-lasts. AKTIEBOLAGET LINHAM. April 10, 1953, No. 9849/53. Class 83 (3). A machine for copying shoe-lasts and similar bodies comprises a rotary model-last holder, a rotary last-blank holder, a model follower, a cutting tool holder, a primary width grading mechanism for enlarging and reducing and at least one secondary width grading mechanism co-operating with the primary mechanism and operating periodically in timed relation to the rotation of the model to superimpose a variable additional increment on the primary width grading motion for any setting of that mechanism. The pattern M, Fig. 1, is rotatable on an axuiliary slide 10 which may be moved relatively to the main slide 7, carrying the right- and left-hand lasts to be produced, by automatic length-grading mechanism. The lasts are connected to rotate together by gearing, the left-hand last L rotating in the reverse direction to the others. The rotary cutters 17, 18 are carried by a vertically movable frame 19 sliding in guides 29, 30, of the bed. The cutter frame carries vertical guides 22, 23 for a tracerroller carrier 21 which may thus move relatively to the tool frame for width-grading purposes by mechanism described below. The primary width-grading mechanism comprises a bellcrank 43 with the intermediate point pivoted at 45 to the slide 21 for the tracer-roller. One end 48 of the lever engages a guide-groove 44 in the frame 19 and the other end engages a guide-groove 46 in a member 38 pivoted at 39 to a transverse slide 32. A quadrant 40 with guide-groove and clamping nut enables the member 38 to be adjusted to the left or right of a vertical position whereby the width of the lasts may be increased or decreased respectively, relative to the pattern. The slide 32 may be given a transverse movement automatically by a bell-crank 92, 93, and rod 90 which is moved vertically by an eccentric 73, 74, Fig. 2, driven from the gearing for rotating the lasts. A vertical slider 76 is moved by the eccentric and transmits movement to a rocker 80 pivoted at 81. This in turn moves a member 84 vertically through a pin-and-slot connection 83, 82. The member 84 slides in a bush 86 which may be adjusted lengthwise to vary the amount of movement finally transmitted, through the pin-and-slot device 89, 88, to the vertical rod 90. The bush 86 is moved by a lever 98 pivoted at 99, the other end of which is connected to the mechanism for longitudinal movement of the lasts and pattern. Additional secondary width grading mechanism comprises a further slide 35, in which the slide 32 is guided, which may be moved automatically by a bell-crank 56, 57, Fig. 1, and a vertical rod 54. The latter is reciprocated by an eccentric pin 52 rotated by gearing connected to the main gearing with a 2: 1 ratio. Further mechanism is described for moving the pattern-slide 10 relative to the main slide 7 carrying the lasts, to obtain an enlargement or reduction in length corresponding to the width-changing mechanism.