MOTION IN WEAVING (Warp brake stop motion)

Another auxiliary motion which are use to stop the machine and to improve the quality of fabrics are coming one by one.

Mechnical warp stop motion:-

The warp stop motion is an auxiliary loom motion . The main object of a warp stop motion is to stop the loom immediately when an end (warp) breakage occurs during the loom working . The break stop motion plays a very important role to improve the quality of the fabric and productivity of the loom. If a breaks occurs and the loom gets continued to run , the broken end coming from the warp beam gets accumulated behind the eye of the heald wire . This yarn deposition causes multiple ends breakages and this multiple end breakages takes a long time to redraw these broken ends. Thus when the loom gets continues to run in case of end breakage the fabric getting produce becomes defective. Thus the quality of the fabric get affected. The warp break stop motion helps to increase productivity and improve the quality of the fabric getting woven on the loom.

Types of warp break stop motion:-

The types of warp break stop motion are given below;

a) Mechanical warp break stop motion.

b) Electrical warp break stop motion.

c) Electronic warp break stop motion .

Structure of mechanical warp break stop motion:-

1) This mechanism consists of a reciprocating baar, oscillating device, knock-off device, and drop wires.

2) The complete reciprocating baar made of three components. The fixed outer baar consists of two plates.

3) The reciprocating baar slides between these two plates of fixed outer baar. The top edge of the outer baar and reciprocating baar get oscillated.

4) In order to ensure that the drop wire will fall into the lowest cut out point of both baars, it is necessary for reciprocating baars to be slightly higher than the two fixed outer baars.

5) The number of castillated baars depend upon the number of ends per inch used in warp beam. 4 to 8 castillated baars are normally used.

6) The one end of each castillated baar gets connected through the slot in the drop wire. The reciprocating baar is connected with the forked bracket.

7) The forked bracket is attached with fulcrum lever. This fulcrum lever held in the bottom of the rocking diamond-shaped cut out of the cam lever.

8) The lower end of the fulcrum lever get spring loaded . The one end of release trip lever rests upon the spring loaded lever.

9) The release catch trip lever gets fulcrumed as shown in the figure.

10) The other end of the release catch trip lever rests infront of the lower end of the lifting catch.

11) The oscillating mechanism is connected to the crank shaft through the sprocket wheel and chain . The one end of the cam lever is connected to the eccentric.

Mechnical warp break stop motion.

Working principle of mechnical warp break stop motion:-

The cam lever and eccentric are connected through the connecting rod . When the eccentric rotates , it imparts oscillating motion to the cam lever.

The fulcrum lever is connected to the cam lever in the middle. A forked bracket is attached at the top of the fulcrum lever.

When the cam lever oscillates the forked bracket also oscillates. Since the one end of the reciprocating baar is connected with a forked bracket so that the reciprocating baar also make back and forth movement.

When the loom operated the drop wire rests upon the warp end due to warp tension.

Enough clearance between the top edge of the reciprocating baar and the slot of the drop wire.

This clearance makes a free passage back and forth movement of the reciprocating baar between two fixed outer baars.

The position of the release catch trip lever doesn’t change in this situation and the loom gets continues to run.

The drop wires creates a hurdle in the back and forth motion of the reciprocating baar.

The spring loaded end of the fulcrum lever rises in this situation because it can not be rock side-wise.

The release catch trip lever also rises . Now the out side end of this lever falls and allows the lifting catch to slip over the out side end of the cam lever.

As this end of the cam lever rises , it raises the lifting catch, and thus the knocks-off lever slides and through a wire further catch attached to sley at the front end of the loom is raised into line with a projection of the starting handle unit for the loom to be knocked off.

Ref:-https://www.textileadvisor.com