Patent GB-196379-A (GB)
Title: Improvements in or relating to cutter-grinding devices
IPC: B24B3/40
Filed: 1922-01-23
Abstract: 196,379. British United Shoe Machinery Co., Ltd., and Gouldbourn, J. Jan. 23, 1922. Cutting-edges, shaping.-A machine for grinding cutters, for example, the cutters of a heeltrimming machine, comprises a holder which piesents two cutters to the periphery of a rotating grinding-disc at positions spaced apart about the axis of the disc, the two holders being so interconnected that movements given by the operator to one cutter are exactly reproduced in the other cutter, both thus being ground to the same form. The machine comprises a column 1 supporting the shaft 3 of a grinding-disc 4 and having secured thereto, on a bracket 7, an inclined slideway 8 carrying a slide 9 movable towards and from the shaft 3 by a screw 10. On the slide is rotatably and slidably carried a shaft 16 parallel to the shaft 3; movement of the slide moves the shaft 16 radially of the shaft 3. At one end the shaft 16 carries a cutter-holder, and at the other end it passes through a slot 17, Fig. 2, in a casing 18, and carries a block 20 guided in a groove 21 in the cover 22 of the casing; the shaft also carries a gear segment 23. On the slide 9 is a lug 26 carrying a shaft 28 on which is pivotally mounted a member 29 having rotatably and slidably mounted therein a shaft 30 parallel to the shaft 16 and carrying at one end a cutter-holder similar to that on the shaft 16. At the other end, the shaft 30 passes through the casing 18 and has secured thereto within the casing a gear segment 35; the shaft also engages the end of a link 32 pivoted at 33 to the bracket 7. The segments 23, 35 are engaged by a rack 36 slidable in the casing, and the shafts 16, 30 are constrained to move together axially by segment-plates 40, 41 secured to the shafts. The cutter-holders each comprise an arm 42, Fig. 3, projecting from the shaft and having secured thereto a guideway 44 for a slide 45 movable by a screw 46. The cutter 49 is clamped between the slide and a block 50 secured to the arm 42; locating ribs 52 are formed on the block and on the arm and a pin 55 is provided to act as a stop for locating the end of the cutter. The entry of dust into the guideway is prevented by a thin metal strip 53 having its ends secured to the slide and passing round semicircular caps 47, 60 on the guideway; the bearings of the shafts 16, 30 also are protected from dust by protectors 54 comprising leather washers stitched together. In operation, one cutter-holder is moved by the operator, by rotation and axial movement of the shaft of the holder, to give the desired shape to the edge of the cutter, the other cutter following those movements. The member 29 and the link 32 are so arranged and proportioned that when the slide 9 is moved, to compensate for wear of the grinding-disc, or to alter the aspect of the ground face of the cutter in relation to the body thereof, the position of the second cutter is correspondingly changed. The weight of the mechanism is balanced by a spring 57 or by a weighted arm. According to the Provisional Specification, one of the cutter-holder shafts is mounted on the slide and the other, in pendulous levers, below the slide, the free ends of the levers abutting in concavities in plates secured to the bracket and held against the plates by springs; or the ends of the levers may be pivoted to links. The cutterholders are situated centrally of their shafts.