Various important part of plain power loom

Back rest

Fig. Back Rest

When the heald shaft are open for shedding the back rest move downward by oscillating movement. (N to P) When the heald shaft are close then the back rest move on original position (N) by oscillating movement. (P to N)

When shed is open more length require so back rest is provide length from the weaver’s beam by oscillating movement.            For non-automatic loom weaving plain cotton fabric, the back rest is given an oscillating movement by mean of a cam on crank shaft through a leaver to ease the warp thread during shedding

Lease Rods

Fig. Lease Rods

The main use of the lease rod is to keep the warp thread in given relation to Each other. So that if a thread breaks its proper place can easily be found out so that it can be avoided from getting crossed with the other thread at the back. They consist of two wooden rod of different size (cross section) generally covered with smooth surface. The larger lease rod is nearer to back rest and the smaller is nearer to the healds.

Heald Shaft

Fig. Heald Shaft

In a plain power loom the heald shaft, shuttle and sly are operated by mechanism that are set in motion by motor through a crankshaft and a bottom shaft. The heald shaft move up and down by shedding mechanism. The motion is obtained from the bottom shaft or counter shaft that carries the tappet so the warp shed is divided into two layer and it forms a shed

• Lifting of warp 
• Formatting a gap
• To take up warp & down as per design order

Shuttle

The shuttle is pushed into the warp shed by a picker that gets activated by a picking mechanism normally the shuttle is kept in a shuttle box. When the shuttle is pushed it reaches the opposite box. The picking mechanism is set in motion by the bottom shaft.  

Weft package that know as Pirn (B) is feed in to the package holder. And the weft yarn is unwind and pass through the shuttle eye as tension required. Shuttle and second eye’s complicated it means guidance is increase for the more tension is required.

Sley
The crank shaft operate the sley through the crank and crank arms. The sley get a to and fro motion. As the sley reciprocates. The reed, which is fixed to the sley. Also gets a to and fro motion. The reed thud beat up the weft into the feel of the cloth. 

·        Reed

A reed is a comb fixed in the sley by means of a reed cap at the top. It secured at the bottom in between the race board and the reed case. The comb consist of flat metal wire strips or wire spaced uniformly. The open space between two wire points is known as “dent”. The warp yarn are passed through the dent in the reed
Function of reed

Fig. Reed

• It beat up the last pick is pushed up to the fell of the cloth.
• its determine the cloth width.
• it keeps the warp threads in their respective position.
• its determine the end per inch.
• to manage the shuttle path or shuttle guide.

  

·        Temple

The main function of the temple is to grip the cloth ad hold it at the same width as the warp in the reed before it is taken-up.

Temple

 

• To avoid contraction of cloth after interlacement of wrap and weft
• To keeps the width of the cloth equal to the width of the warp in the reed.
• To overcome the drag on the selvedge thread when the shuttle pass over the race
• To prevent the edge threads from chaffing by the reed wires and the reed wire from being injured by the warp thread.

·        Shuttle box

It is the housing for the shuttle and is made of wood. It has a spindle and a picker. It may also accommodate the picker without spindle. The top and side of the box towards the sley race are open. The shuttle dwell inside the box for the intermediate period between two successive picks.

·         Picker

The picker is a piece made either of leather or synthetic material. It may be placed on a spindle or grooved in the shuttle box. It is used to drive the shuttle from one box to another box. It also sustains the force of the shuttle while entering the box.