Motion of Heald
Shafts, Shuttle and Sley
In a plain power loom
the heald shafts, shuttle and sley are operated by mechanisms that are set in
motion by a motor through a crankshaft and a bottom shaft. The heald shafts
move up and down by the shedding mechanism. The motion is obtained from the
bottom shaft or counter shaft that carries the tappets. So the warp sheet is
divided into two layers and it forms a shed.
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 arrival of the shuttle in the opposite box is
confirmed by shuttle checking devices. The picking mechanism is set in motion
by the bottom shaft.
The crankshaft operates
the sley through the crank and crank arms. The sley gets 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 thus beats up the weft into the fell of the cloth.
Warp and Cloth
Control
The shuttle is pushed
into the warp shed by a picker that gets activated by a picking after beating
up the weft into the fell of the cloth; a take-up motion draws the cloth
forward and winds it on to a cloth roller. At the same time the warp is
delivered from the weaver’s beam by a let-off motion.
These two motions are
operated simultaneously and at a constant rate. I.e. the rate of cloth take-up
is so set as to be equal to the rate of warp let-off. The take-up motion is
operated through a sley stud and gear mechanism. The let-off motion operates by
the pulling action of the cloth.
The two temple pieces
located at the selvedges of the cloth control width.
