GB553653A - Improvements in or relating to knife sharpening mechanism for cutting machines - Google Patents

Abstract

553,653. Cloth cutting machines ; knife sharpeners. STEVENS, A. H. (Eastman Machine Co.). July 18, 1942, No. 10033. [Class 60] In a portable, cloth cutting machine having a vertically reciprocating knife and powerdriven knife-grinding mechanism moved up and down the blade, as in U.S.A. Specification 2,183,787, the grinding device is mounted on a carriage traversed by a rack thereon which is engaged by either of two oppositely driven pinions mounted on a rocker, a trip being provided which is movable with the carriage and effects the change over to reverse the travel of the rack and carriage at its lowest point. The grinding device comprises endless bands 15, 16 passing over pulleys 23, 24 mounted on shafts 20, 21 carried by a head 17 and splined to intermeshing pinions driven by a third pinion splined to a shaft 29 ; the latter is driven by worm gearing from a wheel 33 carried by a casing 34 which is pressed downwards by springs to bring the wheel 33 into driving engagement with the crank disc 14 which reciprocates the knife. This movement is normally prevented by the upward movement of the shaft 29 at the end of the return movement of the head. The shaft 29 drives a cross shaft 51 which drives the intermeshing pinions 44, 45 mounted on a centrally pivoted rocker 55 and adapted to engage the rack 40 to which the head 17 is fixed. The rocker is operated by a spring-loaded hand lever 60 which is engaged by a trip member 70 on the rack at the end of the traverse to tilt the rocker and bring the other pinion into engagement with the rack to effect reversal. The rack and head move upwards till the latter engages the end of the shaft 29 to raise it slightly and move the wheel out of driving engagement.