Overlock machine seams are characterized by sewing along the right-hand edge of the material, with the straight needle punching the material and the upper and lower curved needles working in conjunction with the hook to form a 500-type seam that wraps around the edge of the material. In order to achieve a neat seam appearance, all overlock machines are fitted as standard with an up and down moving cutter set to cut the material to give a neat edge, which guarantees excellent quality and stability of the seam formation during sewing.
Composition and operating principle of materials trimming device
Overlock machine cutter set consists of a moving knife and a fixed knife, located in front of the center of the needle movement on the right side of the installation, the cutter set of cutting line and the distance from the center of the needle determines the width of the overlock stitch. Usually, the fixed knife is installed in the lower part of the needle plate, the fixed knife blade and the needle plate plane aligned; the moving knife is installed in the upper part of the needle plate on the moving knife frame, as shown in the red circle in the left part of pic#1. Dynamic knife through the transmission mechanism so that the dynamic knife frame swing drive dynamic knife to do up and down reciprocating motion, when the dynamic knife falls with the fixed knife engagement will cut the seam, as shown in pic#1.
PIC#1
Overlock machine cutter drive mechanism is more complex (pci#2 as shown), and most of the institutions are inside the casing, only a small number of institutions exposed, its working principle is described below:
Cutting knife driving force is from the spindle, when the spindle(#10) clockwise rotation, through the cam(#8) driven moving knife linkage assembly(#9) to do up and down movement; moving knife linkage(#9) upper end connected to the moving knife crank(#12), so that the moving knife axle(#13) to do the swing movement, the left end of the moving knife axle(#13) driven moving knife frame(#14) so that the moving knife(#16) (moving blade through the moving knife seat fixed in the moving knife frame) to do the up and down oscillating movement; in the spindle's continuous rotation, the moving knife(#16) Under the continuous rotation of the main shaft, the movable knife(#16) will thus form a continuous up and down movement, engaging with the fixed knife(#5) installed below, and cooperating with each other to achieve the effect of cutting the sewing material, as shown in pic#2
PCI#2
1-spring; 2-fixed knife seat; 3-fixed knife pressure plate; 4-fixed knife pressure plate fixing screw; 5-fixed blade 6-fixed knife seat; 7-motorised knife seat; 8-cutting knife cam; 9-motorised knife linkage assembly; 10-spindle; 11-cutting knife shaft tightening ring; 12-motorised knife crank; 13-motorised knife shaft; 14-motorised knife holder; 15-motorised knife fixing screw; 16-motorised blade;
In order to facilitate installation and adjustment, the cutter knives are mounted on the adjustable position of the knife holder by means of pressure plates or screws, which can be easily adjusted in the height, left and right directions. Cutting knife set by the moving knife and fixed knife composition, moving fixed knife are made of high hardness steel sheet shape, some moving knife head set with super carbide steel, greatly improving the hardness of the moving knife and abrasion resistance, usually the hardness of the moving knife is greater than the hardness of the fixed knife, see Figure 4 shows. Dynamic blade shape is relatively complex, the head of the dynamic knife extends the elongated shape is in order to have a reliable guiding role in the movement, and to avoid direct contact between the dynamic blade, the tail of the long groove is a screw fixed blade as well as high and low position adjustment with.