GB1388519A - Automatic sharpening device - Google Patents

Abstract

1388519 Sharpening T OHASHI 2 Nov 1973 [4 July 1973] 51001/73 Heading B3D A device for automatically sharpening an edged tool, such as cutlery, razor blades or scissor blades, comprises a movable block 5, Fig. 1, reciprocable above a base-plate 1, means 8 mounted on the block for securing the tool, a cylindrical grinding member 20 angularly disposed with respect to the moving direction of the block, means for pivotally inclining the securing means on the movable block to press down one edge side portion of the tool, and driving means for rotating the cylindrical grinding member and reciprocating the block. The block 5 is generally U-shaped and mounted for sliding movement along a pair of rods 6a, 6b carried by supports 2a, 2b upstanding on the base-plate 1. A pair of rods 7a, 7b are rotatably supported in the arms 5b, 5c of the block and are interconnected by gears 9a, 9b secured to the rods. Rod 7a is also secured to the securing means 8 which has a holding means 11 for a razor 12, a spring 13 preventing a sheath portion 12a of the razor jumping away during sharpening. A tip portion 8b of the member 8 receives a neck portion of the razor and is mounted on an axial portion 8c for slight pivotal movement permitted by a small space between the parts 8a, 8b. An arm 10 is also secured to the rod 7a and is acted upon by a spring 15 to urge the securing member into one or other of its two pivotal positions. A second arm 17 is secured to the rod 7b and has a projection 18 which, at the ends of the reciprocating movement of the block engage guides 3a, 3b to effect reversing of the securing means 8 and razor 12. The razor engages a cylindrical grinding member 20 of balsa or steel which is carried by a mount 23 angularly adjustable about a pivot 24 to positions determined by a scale 26. The grinding member is driven by gears 31, 32, Fig. 3, from a pulley 28 connected by a rope drive 29 to a disc 27 rotated by worm-gearing 41, 43 from a motor 42. A further disc 33 is carried by the pulley 27 and is connected by a rod 34 to a disc 36 having a quadrant 38 engaging a rack 39 secured to the block 5 which is thereby reciprocated. The disc 33 is adjustable on the pulley 27 to reduce the movement of the arm and hence the length of stroke of reciprocation of the block 5 so that the projection does not engage the guides 3a, 3b and the securing means is not reversed when a scissor blade, which does not require reversing, is mounted in the device. In another embodiment, the spring 15 is not secured to the block 5, as shown in Fig. 1, but is secured to a separate block, which, during movement of the block 5, slides along an inclined guide rail to increase the pressure between the tool and grinding wheel towards one end of the movement of the block 5, which increase in pressure is used during the sharpening of curved blades. In an embodiment for sharpening a scissor blade 47, Fig. 5, the blade is mounted in an attachment 46 carried by the movable block 5 and has means 48 for adjusting the angle of attack of the blade with the grinding member 20. A member 51 on the attachment has a wheel 51a which engages a rod 49 supported at opposite ends by springs 50 from the supports 2a, 2b, that at support 2a being the stronger so that the blade end which is curved and warped is pressed with greater pressure against the grinding member.