GB1432873A - Sharpening devices - Google Patents

Abstract

1432873 Sharpening cutters in situ MASSEYFERGUSON Inc 9 July 1973 [10 July 1972] 32696/73 Heading B3D A device for sharpening a reel type cutter, such as the cutter 17 of a forage harvester, comprises a rotatable grinding element 58 movable in the axial direction of the cutter, and means adapted to drivably interconnect the grinding element and the cutter for effecting angular movement of the cutter about its axis as the element is moved in the axial direction to maintain the element in proper relationship with successive portions of a helical blade of the cutter. The cutter 17 has a plurality of adjustable blades 20 having edges 22 to be sharpened and is mounted on a shaft 19 rotatable between side plates 12, 14 of a housing 10 having an opening 13 which, in use, is closed by a door 16 opened to provide access to the cutter during sharpening. A bracket 24 is secured to the housing and is formed with guideways 28, 30 which extend parallel to the axis of the cutter 17 and are engaged by rollers 32 of a carriage 34. The carriage has boss portions 40 receiving parallel guide rods 47 which are also received in boss portions 42 of a plate 38 carrying a motor 36 for driving the grinding wheel 58. A screw 50 can be rotated by a handle 54 to axially adjust the grinding wheel 58. The carriage 34 is movable along the guideways 28, 30 by rotation of a screw 65 which is connected by gears 120, 118 to a handle 114 and by bevel gears to a transmission member 92 having a screw-threaded portion 90 engaging a socket 84 rotatably mounted on a lever 82, in turn, rotatably mounted on the shaft 19 of the cutter. An indexing disc 70 is clamped to the shaft 19 and has notches 72 which correspond to the blades 20 and are selectively engaged by a rachet 126 mounted on the lever 82 and urged by a spring 124 against the disc 20. During cutting of forage, the carriage 34 and grinding wheel 58 are disposed at one side of the housing 10, the door 16 is closed, and the rachet 126 is in a position (shown dotted) disengaged from the indexing disc so that the disc can rotate with the cutter. When the blade requires sharpening, the door 16 is opened, the ratchet 126 is engaged with a notch of the disc 20 and the handle 114 is rotated to rotate the screw 65 so that the carriage 34 is moved along the guideways 28, 30 with the wheel engaging a blade 20 of the cutter, rotation of the screw 65 causing rotation of the rod 92 and movement of the lever 82 so that the ratchet 126 causes simultaneous rotation of the cutter 17.