Thursday, February 18, 2021

Over-pick picking motion

 Over - pick picking motion

Over-pick motion:

In this kind of picking motion, the weft yarn is inserted into the shed of over side of the loom. We can say in other words the the picking mechanism which hits the shuttle of over side of the loom is  called over-pick motion.

Structure and woking of over-pick motion:

The over-pick motion receives motion through bottom shaft. This mechanism is fitted at both sides of bottom shaft. A picking tappet is mounted on the bottom shaft with the help of clamp and bolts. These bolts also helps to adjust the timing of picking. A vertical is used in this motion. One end of vertical shaft is connected to foot step bearing. This vertical shaft passes through another bearing at almost middle of this shaft. This vertical shaft can rotate in any direction. A cone is attached in the slot of vertical shat. This cone is mounted with the help stud and bolts. It can move freely in any direction. A pulling spring is also attached to vertical shaft.

A picking stick is mounted at the top of vertical shaft. A angular adjustment system helps to adjust the angle between picking stick and slay.  A picking strap is attached to other end of picking stick. The effective length of picking strap can be adjusted as per requirement. The ther end of the picking strap is attached to picker. This picker is made of nylon. This picker slides on the picking spindle. The shuttle rests in shuttle box in front of picker.

When the bottom shaft rotates, the picking tappet mounted on the bottom shaft also rotated in the same direction. The cone mounted on the vertical shaft always touches the picking tappet. When the picking tappet nose touhes the cone and then pushes forcefully, the vertical shaft recieves angular motion. Since the picking stick is mounted on this vertical shaft, so that picking stick receives partial angular motion. The picker attached with one end of picking strap hits the tip of shuttle. Thus the shuttle travels from one shuttle box to another shuttle box. 

As soon as the picker hits the shuttle, the vertical shaft returns it's original position by pushing spring. The bottom shaft rotates at half speed of crank shaft. One rotation of bottom shaft generes two picking cycles. 

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