After the needle has risen a certain distance, the tip […]
After the needle has risen a certain distance, the tip of the hook bed begins to hook into the loop, and the hook tip hooks the loop and continues to roll. When the loop is sent to the guide rail of the hook frame, the loop is divided by the shuttle. The hook of the line is hooked, and the opportunity needle should rise by about 2 mm from the lower limit. The branch hook on the hook frame should be close to the wire loop, so that the end of the wire loop is moved to the back of the guide rail. The angle between the hook hook and the needle movement axis is about 50°, which is outside the shuttle tip. The wire loop is hooked at 45° on the convex surface of the frame, and the rolling is continued. The end of the wire loop is hooked on the branch hook. In order to smoothly slide the wire loop onto the outer surface of the shuttle frame, the oblique edge of the tail of the wire plate is the wire loop. The thread head is turned outwards, and the rear part of the wire loop is hooked by the hook of the shuttle frame, and slides down to the bottom of the shuttle frame. At this moment, the needle is withdrawn in the hook mechanism.
Since the shuttle wire is very smooth, the wire loop slides smoothly out from the bottom of the shuttle frame, and when the shuttle tip is rotated through 180°, the take-up lever rises and the remaining part of the wire taken before the take-up bar is taken up. The tip of the wire hooks the wire loop to continue to rotate. The front half of the wire loop is under the wire guide plate. After the 45° slope of the convex surface of the outer frame, the edge of the moving wire plate is gradually raised above the shuttle frame, and the front half wire loop is opened outward. . The rear half wire loop is hooked by the shuttle branch hook, and the wire loop is separated front and rear. Finally, the front and rear loops are sleeved over the shuttle frame, and the bottom thread is sleeved at the center, and the wire loop is tightened by the thread take-up rod to form a stitch. The operation cycle of the hook mechanism is between 203° and 312°, which is the stage of hooking the wire loop and enlarging the wire loop. Between 312° and 320°, the needle is withdrawn from the bobbin case and the exit phase is 0° to 180°. One turn of the upper shaft, two turns of the hook, and the second rotation. The principle of the hook forming the stitch is basically the same as that of the shuttle, but the process and method of forming the stitch are different from the shuttle: the hook is for the angular velocity rotary motion, and the shuttle is for the non-equal speed reciprocating swing motion. In the upper and lower reciprocating motion of the needle (one rotation of the main shaft), the hook rotates at an equal angular speed for two weeks, and the shuttle swings back and forth once; the hook is fixed by the hook frame, and the rotary bed is rolled, it is The tip of the shuttle bed hooks the wire loop, and the hook is hooked by the hook to make it bypass the bobbin case and the bottom and upper sides of the shuttle frame, and the wire is separated from the surface of the hook plate to form a wire loop.
Nowadays, there are hundreds of kinds of various kinds of rotary hooks in the world. At present, the commonly used rotary hooks in the country can be roughly divided into three categories: among sewing machines, sewing machines stitched with lock stitches are the most popular. Most of these sewing machines use a hook to hook the wire loop with its tip, and at the same time enlarge the wire loop and guide the wire loop around the bobbin to form a lock stitch.