Instruction for edge trimming knife sharpening of M-Type shoe sewing machines 1. Introduction This instruction is a supplement to the instruction for use of electric table sharpener; thus the scope of use is limited to sharpening of edge trimming knives on industrial sewing machines. 2. Product designation The sharpener is designated only for sharpening of edge trimming knives for the trimming device of the industrial sewing machines. 3. Safety instructions Attention! Before using the sharpener, carefully read the enclosed instruction for use of the electric sharpener ELKO, type B-150. At any handling the edge trimming knives it is necessary to keep careful to prevent operator s injury with the trimming knife edge. It is prohibited to - use the sharpener to sharpen or grind other tools than the trimming knives. - at the trimming knife sharpening on a thin grinding wheel, develop lateral pressure on the grinding wheel with the sharpened trimming knife. - clamp the trimming knife in the respective fixture in a different way than illustrated in the instructions, or to sharpen the trimming knife by hand. 4. General notice The working procedure of the trimming knife sharpening is described in the pictures in this instruction; it consists of three phases: a) dressing of grinding wheel b) trimming knife sharpening in respective fixture c) polishing of burr on a felt wheel 1
5. List of trimming knives for M-Type shoe sewing machines Knife type A C Y N Knife number S080 870234 1) S080 870239 S425 311018 2) 0887 330010 Machine type 888 oblique trimmer 888 oblique trimmer 888 bottom trimmer 887, 888 vertical trimmer Knife shape Clamp No. BN-4-058 S BN-4-061 S BN-4-075 S BN-4-085 S Wheel type wide wide narrow wide Wheel shape 1) alternatively it is possible to supply a trimming knife made of sintered carbide No. S425 870237 or a narrow trimming knife No. S080 870238 2) alternatively it is possible to supply similar knives No. S425 311019, S425 311021, S425 311023, and S425 311024 6. Sharpening of trimming knives for bottom oscillating trimmer (machine 888) View of sharpener - A grinding wheel is clamped on the shaft left side, a felt wheel on the right side. - A switch is located on the sharpener front side for its start-up. - A control wheel of feed screw with a scale is located on the front side of the sharpener equipment. - A feed slide rest for clamping the fixture for a bent knife Y is located by the left wheel. 2
Grinding wheel dressing - Grip the wheel dresser holder with one hand and by swinging movements cross the wheel width from the left to the right. - With the other hand slowly turn the control wheel of the feed screw, while the slide rest with the wheel dresser is shifted to the bite. The control wheel turn must be minimal, it should correspond to maximum one division on the wheel scale. - Dressing is completed after finishing of all active area of the wheel. Detail of dressing equipment - After some time /approximately 10 dressings/ it is useful to loosen the screw M4 and turn the dressing diamond by 90 ; thus its efficiency is increased. Caution! At subsequent dressing always move the slide rest from the wheel, and again move the diamond dressing wheel to the bite; thus the diamond and wheel damage or crushing or possible injury will be prevented. 3
Preparation for sharpening - Loosen the screw M8 by approximately by 4 mm, slightly lift up and turn the dressing wheel holder by 90 ; thus it will be tilted off from the working position, and you will obtain some space for the clamp with the trimming knife. - After snapping in the groove, tighten the screw again. - You will prepare the dressing wheel for a repeated dressing in the same way. Curved knife clamping in sharpener - Put the clamp for the curved knife Y onto the slide rest fork. - Loosen the grooved screw M5 and insert the curved knife in the groove according to the picture and tighten the screw. - With the screw M4 the clamp height can be adjusted, and thus the knife position against the wheel can be regulated. 4
Curved knife edge sharpening - By moving from the right to the left, move the knife with its recess against the wheel. - Slightly lay the knife on the rotating wheel, for a greater reduction, make this in several steps so that the knife edge does not get thin. Polishing wheel preparation - Lay and press polishing paste on the rotating felt wheel and spread it evenly on the whole perimeter. 5
Knife burr polishing - Lay the knife on the rotating wheel so that the wheel is rotating on the knife edge, and polish the burr, which arises after sharpening, off the knife. Caution! On the laying of the knife edge, it may drive into the felt wheel, which could cause the operator s injury by flinging the knife out. 7. Sharpening of trimming knives for oblique upper trimmer (machine 888) Knife geometry 6
View of sharpener - A grinding wheel is clamped on the shaft left side, a felt wheel on the right side. - A control wheel of feed screw with a scale is located on the front bottom side of the sharpener attachment. - A feed slide rest for attachment of the respective clamp for a knife with a straight edge or a knife with curved edge is located by the left wheel. Grinding wheel dressing - In the first phase of dressing it is necessary to dress the wheel face with a dressing stone. It is important to keep the collinearity of the wheel face with the sharpener axis. - Grip the wheel dresser holder with one hand and by swinging movements cross the wheel width from the left to the right. - With the other hand, slowly turn the control wheel of the feed screw, while the slide rest with the wheel dresser is shifted to the bite. The control wheel turn must be minimal, it should correspond to maximum one division on the wheel scale. - Dressing is completed after finishing of all active area of the wheel. - After some time /approximately 10 dressings/ it is useful to loosen the screw M4 and to turn the dressing diamond by approximately 90 ; thus its lifetime is extended. 7
Wheel shape check - Angle and wheel bevel length (4x45 ) can be checked with a supplied measuring gauge. - Measurement and check of the wheel shape must always be carried out after the machine switch off and the wheel stop! Caution! At subsequent dressing always move the slide rest from the wheel, and again move the diamond dressing wheel to the bite; thus the diamond and wheel damage or crushing or possible injury will be prevented. Preparation for sharpening - Loosen the screw M8 by approximately 4 mm, lift and turn the dresser holder by 90 ; thus it will be tilted from the working position and space for clamps with knives will appear. - After snapping in the groove, tighten the screw again. - The dresser will be prepared for dressing process in the same way. Clamping in sharpener of knife with straight edge - Put the slide rest fork with marking A and C on the movable slide rest axis. - Put the clamp for the curved knife A onto the slide rest fork. - Loosen the screw M5 and slide the knife to be sharpened into the loosened clamp. - Push the knife close to the measuring gauge inserted in the clamp and lock the knife by tightening the clamp. - With the screw M5 placed by one of the fork shafts, the clamp height can be additionally adjusted, and thus the knife position against the wheel can be regulated. 8
Trimming knife edge sharpening - By moving from the right to the left, move the knife against the wheel. - Slightly lay the knife on the rotating wheel, for a greater reduction make this in several steps so that the knife edge does not get thin. Beveled edge knife clamping in sharpener - Put the slide rest fork with marking A and C on the movable slide rest axis. - Put the clamp for the curved knife A on the slide rest fork. - Push the curved knife close to the measuring gauge inserted in the clamp and lock the knife by tightening the clamp. - With the screw M5 placed by one of the fork shafts, the clamp height can be additionally adjusted, and thus the knife position against the wheel can be regulated. Trimming knife edge sharpening - By moving from the right to the left, move the knife against the wheel. - Slightly lay the knife on the rotating wheel, for a greater reduction make this in several steps so that the knife edge does not get thin. 9
Knife taper grinding - According to the enclosed drawing, grind a slight taper on the knife edge side. Polishing wheel preparation - Lay on and press against polishing paste on the felt wheel and spread it evenly all over the whole perimeter. Knife burr polishing - Lay the knife on the rotating wheel so that the wheel is rotating on the knife edge, and polish the burr, which arises after sharpening, off the knife. Caution! On the laying of the knife edge, it may drive into the felt wheel, which could cause the operator s injury by flinging the knife out. 10
8. Knife sharpening for upper vertical trimming (machines 887 and 888) The knife sharpening process for vertical trimmer is similar as above, paragraph 7. Knife geometry Grinding wheel dressing - In the first phase of dressing it is necessary to dress the wheel face with a dressing stone. It is important to keep the collinearity of the wheel face with the sharpener axis. - Grip the wheel dresser holder with one hand and by swinging movements cross the wheel width from the left to the right. - With the other hand, slowly turn the control wheel of the feed screw, while the slide rest with the wheel dresser is shifted to the bite. The control wheel turn must be minimal, it should correspond to maximum one division on the wheel scale. - Then it is necessary to make bevel 4 x 45 on the wheel right side. - Dressing is completed after finishing of all active area of the wheel. - After some time /approximately 10 dressings/ it is useful to loosen the screw M4 and to turn the dressing diamond by approximately 90 ; thus its lifetime is extended. Wheel shape check - Angle and wheel bevel length can be checked with a supplied measuring gauge. - Measurement and check of the wheel shape must always be carried out after the machine switch off and the wheel stop! Caution! At subsequent dressing always move the slide rest from the wheel, and again move the diamond dressing wheel to the bite; thus the diamond and wheel damage or crushing or possible injury will be prevented. 11
Preparation for sharpening - Loosen the screw M8 by approximately 4 mm, lift up and turn the dresser holder by 90 ; thus it will be tilted from the working position and space for clamps with knives will appear. - After snapping in the groove, tighten the screw again. - The dresser will be prepared for the dressing process in the same way. Knife clamping in sharpener - Put the clamp (2) on the slide rest axis (1). - Loosen two screws M3 (3) and slide the trimming knife (4) on. - Lock the knife by tightening of screws (3). - Adjust the rest (5) so that it supports the knife to be sharpened (4) from the bottom side. - Adjust the position of the tilting limiter (6) and tighten its screw (7). - With the screw M5 the clamp height can be additionally adjusted, and thus the knife position against the grinding wheel (8) can be regulated. 12
Trimming knife edge sharpening - By moving from the right to the left, move the knife against the wheel. - Slightly lay the knife on the rotating wheel, for a greater reduction make this in several steps so that the knife edge does not get thin. Knife taper grinding - According to the enclosed drawing, grind a slight taper on the knife edge side. Polishing wheel preparation - Lay on and press against polishing paste on the felt wheel and spread it evenly all over the whole perimeter. Knife burr polishing - Lay the knife on the rotating wheel so that the wheel is rotating on the knife edge, and polish the burr, which arises after sharpening, off the knife. Caution! On the laying of the knife edge, it may drive into the felt wheel, which could cause the operator s injury by flinging the knife out. 13