Patent GB-979003-A (GB)
Title: Machine for sharpening garden and like shears, scissors, knives and like cutting tools
IPC: B24B3/36
Filed: 1962-06-20
Abstract: 979,003. Grinding; drilling machine details. L. F. BLAKESLEY. Sept. 6, 1963 [June 20, 1962; March 9, 1963], Nos. 23672/62 and 9450/63. Headings B3C and B3D. A grinding machine for sharpening shears, scissors, knives and the like comprises a grinding wheel 5, Figs. 2 and 3, rotatably mounted upon a stand 2, and a guide 6 extending adjacent the periphery of the wheel and providing a guiding edge 6a extending generally tangentially, or parallel to a tangent to the grinding wheel for supporting a blade to be ground, the guide being adjustable relative to the grinding wheel and means being provided for retaining the guide in an adjusted position. The grinding wheel is dish-shaped and carried on the vertical shaft 4 of an electric motor 3 suspended from the top of the stand. The guide consists of a plate of generally rightangled shape having a guide edge 6a for supporting the blade as it is moved across the edge of the grinding wheel and a limiting edge 7a which is inclined from the vertical for use when grinding the edge of the blade. The plate is secured to a mounting plate 9 connected by a screw 11 to a bracket 10, and a finger 13 extends from the mounting plate and receives a screw 16 which has an end abutting the bracket whereby rotation of the screw angularly adjusts the guide plate about the screw 11, a spring 17 maintaining the screw in engagement with the bracket. The bracket is mounted on the upper end of a sleeve 19 slidable in an outer sleeve 21, which is secured to the frame 1 by a screw 25 having a thumb-wheel 26 so that the vertical position of the guiding edge 6a can be adjusted to enable a blade to be moved across the peripheral edge of the grinding wheel to produce a hollow or plane surface on the blade; the vertical adjustment also compensates for wear of the grinding wheel. The machine is also provided with a rotary buff 33, Fig. 1, mounted on one end of an electric motor 31, the other end of which carries a drill chuck 35 which co-operates with a sleeve 37 movable by a lever 39, whereby the screw or rivet securing the pairs of blades of scissors or shears together may be drilled out. A plate 41 is secured to the upper surface of the frame and is provided with holes 43 which may be used in co-operation with a punch for knocking out rivets, and slots 42 which may be used in straightening the blades. In an alternative embodiment more suitable for sharpening shears, the guiding edge of the guide plate 6<SP>1</SP>, Fig. 5, is provided with a roller 43 and the limiting edge with parallel rollers 44. The plate also carries a clamp comprising a spring- pressed roller 49 carried at the end of a lever 50 movable between operative and inoperative positions by a hand lever 53 connected to the lever by links 55. The guide plate is angularly adjustable about a screw 46 by a screw 16 engaging a finger 13 on the plate and a bar 45 which is secured to the plate by the screw 46 and mounted on a pair of rods 56 joined to a member 58 movable by a screw 25 having a thumb wheel 61. The axis of the grinding wheel in the second embodiment is inclined at 15 degrees to the vertical, the guide plate being moved parallel to the axis by the thumb wheel 61. In another form of guide plate, the edge has two portions inclined downwardly from the centre and a limiting edge at each end of the plate to facilitate the sharpening of knife blades. In a further form of guide suitable for use in plane grinding, the guide may comprise a platform having a depending rib for attachment to the plate 9 or block 45 and an upstanding portion forming a limiting edge.