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 the overside of the loom. We can say in other words the picking mechanism which hits the shuttle over the side of the loom is called over-pick motion.

Structure and working of over-pick motion:
The over-pick motion receives motion through the bottom shaft. This mechanism is fitted at both sides of the bottom shaft. A picking tappet is mounted on the bottom shaft with the help of a clamp and bolts. These bolts also help to adjust the timing of picking. A vertical is used in this motion. One end of the vertical shaft is connected to the footstep bearing. This vertical shaft passes through another bearing at almost the middle of this shaft. This vertical shaft can rotate in any direction. A cone is attached in the slot of the vertical shaft. This cone is mounted with the help of studs and bolts. It can move freely in any direction. A pulling spring is also attached to the vertical shaft.
A picking stick is mounted at the top of a vertical shaft. An angular adjustment system helps to adjust the angle between picking stick and slay.  A picking strap is attached to another end of the picking stick. The effective length of the picking strap can be adjusted as per requirement. The other end of the picking strap is attached to the picker. This picker is made of nylon. This picker slides on the picking spindle. The shuttle rests in the shuttle box in front of the picker.

Working principle of over-pick motion:

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 touches the cone and then pushes forcefully, the vertical shaft receives angular motion. Since the picking stick is mounted on this vertical shaft so the picking stick receives partial angular motion. The picker attached with one end of the picking strap hits the tip of the 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 its original position by pushing the spring. The bottom shaft rotates at half the speed of the crankshaft. One rotation of the bottom shaft generates two picking cycles. 

Please click on the below video link to watch the full topic in Hindi:

You may also be interested in the following articles:

Let - off motion, secondary loom motion

Take - up motion, a secondary loom motion

Shedding motion, a primary loom motion

Picking motion, a primary loom motion

Beating motion, a primary loom motion

Schematic diagram of loom

Related articles:

No comments:

Post a Comment

Featured Post

Simple calipers and vernier calipers, method of uses and calculations

Calipers: The calipers are very useful instruments. These instruments are used to measure the diameter of the cylinder, bore, bearing size, ...