GB1396116A - Knife sharpening mechanisms - Google Patents

Abstract

1396116 Sharpening machine cutters in situ EASTMAN MACHINE CO 3 Oct 1972 [3 Nov 1971] 45901/72 Heading B3D A knife-sharpening mechanism for a cutting machine 11 having an elongate knife 17, comprises an abrasive knife-sharpening belt 32 mounted on a carriage 21 movable longitudinally of the knife, means for moving the belt relative to the edge of the knife to sharpen a bevel on the knife, and belt guide means 50 on the carriage and including guide block means 48 for pressing the belt into engagement with the knife, the belt guide means being bendable to selectively vary the angle of the guide block means relative to the knife and being sufficiently rigid to remain in its selected position. The cutting machine 11 has a base 12 supporting a slender standard 15 which carries a housing 16 for a motor for reciprocating the knife 17 along a guide 18 in the standard. A presser foot 19 is mounted on a guide bar 20. The carriage 21 of the knife-sharpening mechanism is mounted on the lower end of the shaft 22 which has a double thread and is driven to raise and lower the carriage, a bar 23 stabilizing the movement of the carriage. The carriage is formed with a block 27 from which extend two legs 25, 26 at different levels. A pair of shafts 28, 29 are driven by gearing from the motor and each has a respective pulley 30, 31. Pulley 30 drives an abrasive belt 32 extending about a pulley 33 on a spring- loaded bracket 34 on leg 25, and pulley 31 drives a similar belt 31 extending about a pulley 43 on a spring-loaded bracket 44 on leg 26. The belts are urged into engagement with the knife 17 by wear-resistant coated surfaces 57, 58 of guide blocks 48, 49 on guides 50, 51 secured by welding or brazing to shoes 55, 56 urged about pins 62, 62<SP>1</SP> on the legs 25, 26 by springs 60, 61. The guide blocks 48, 49 can be bent relative to the guides 50, 51 by a tool (70, Fig. 7, not shown), to adjust the angle at which the belts are pressed against the knife. Set screws 77, 78 limit the movement of the shoes towards the knife in the event the belts should drop below the end of the knife. To prevent the guide block 48 from moving below the lower end of the knife, shoe 55 has a portion 75 formed with a finger 79 which engages serrations 80 on an arm 81 urged about a pivot 82 by a spring 84. The serrations are disengaged from the finger for re-setting by a cam operative at the upper end of the movement of the carriage.