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The composition of the leather sewing machine head
- Nov 15, 2018 -

The head of the leather sewing machine consists of a puncturing mechanism, a thread take-up mechanism, a hooking mechanism, a feeding mechanism and a special device.

Stab mechanism The form of the leather product sewing machine puncturing mechanism is basically the same as that of the flat sewing machine, and it is also a crank connecting rod, but the size of the machine is large. The needle tip used is not a normal circle but has a special shape. It pierces the sewing material in a cut manner, which avoids the damage of the leather and reduces the breakage of the needle. The cutting holes of the special-shaped needle tip usually form an angle with the seam, so that each stitch is snug and tidy.

The thread take-up mechanism is mostly a cam wheel type take-up mechanism, which can meet any regular movement of the thread picking stalk. When sewing thick products such as leather and canvas, the needle thread will be greatly damaged when the needle is pierced and the sewing material is withdrawn. The ideal requirement is: when the needle tip hooks the needle thread loop, the thread picking stalk can be correspondingly For a longer pause, when the needle exits the sewing material, the thread is stalked and then the thread is quickly transferred and the stitch is tightened. The cam-type thread take-up mechanism can meet these requirements more than other types of thread take-up mechanism, and the structure is simple, but the parts are easily worn at higher seam speeds, and the speed should not exceed 1500 stitches per minute.

Hooking mechanism The stitching used in the leather sewing machine is much thicker than that of the ordinary sewing machine, so a non-central bobbin shuttle with a large capacity is usually used. Among them, the long shuttle mouth shuttle is one of the more used leather sewing machines. Its characteristic is: when the tip of the shuttle mouth is inserted into the needle thread loop, the loop is kept on the tip of the mouth and does not expand until the needle exits the sewing material. Obviously, when the needle exits the sewing material and then the thread loop is enlarged, the needle thread passes through the sewing material without hindering, and the damage of the sewing thread can be greatly reduced, which is more important for sewing a thick or sticky sewing material.

Feeding mechanisms come in many forms. Generally, the serrated feed tooth for the sewing machine cannot effectively convey the leather with high hardness. In order to achieve better feeding effect and reduce the damage of the leather surface, the leather product sewing machine often uses the feeding roller instead of the feeding tooth. In addition to the roller feeding, there are various forms of upper and lower feeding, upper and lower and needle feeding, which can make the surface of the sewing material not damaged and overcome the multi-layer sewing material. Some types of leather products are equipped with sewing machines. Lubricate the dip tank of the needle thread.