MOTIONS IN WEAVING (Take-up motion):-

B) POSITIVE TAKE-UP MOTION:-

In Positive take-up, motion gets transmitted to take-up roller directly through gear train.

The different types of motions are discussed below;

(1) Five (5) Wheel take-up Motion:-

The process of fabric withdrawn from weaving zone at regular rate and then winding the woven cloth on the cloth roller with continuous progress of weaving is called take-up motion. For doing these two types of mechanism is used. One is five (5) wheel take-up mechanism and the second is seven wheel take-up mechanism. Actually five wheel take-up mechanism is used in case of jute weaving.

Schematic digram of 5 wheel take-up mechanism (motion)

Details of parts in this mechanism.

A=Ratchet wheel=50–60 T

B=Change wheel=1/4

C=Stud wheel=100–120 T

D=Stud Pinion=12–18 T

E=Take-up wheel=60–100 T

F=Take-up roller=15–16 T

G=Finger

H=Take-up lever

M=Pushing a pawl

N=Rotating catch

T= represent the number of teeth in the wheel.

WORKING PROCESS:-

(1) The beam E is set screwed on the beam shaft those of stud pinion D which is link with stud wheel C.

(2) The stud pinion and the stud wheel work loosely upon o stud in a slotted bracket, the slot is concentric with the cloth beam F.

(3) In this Positive take-up, motion is primarily imparted from the sley sword. The finger enters into the shaft if take-up lever H which is fulcrum at I.

(4) A swinging motion is given to the sley sword and this will cause a pawl M to drive the ratchet wheel A and set the train of wheel motion.

(5) Ratchet wheel is moved the distance of tooth by the oscillating pawl for every pick.

(6)Thus motion is transferred to the cloth roller from the ratchet wheel by means of five wheels.

(2) SEVEN (7) WHEEL TAKE-UP MECHANISM:-

Take up motion is used to draw a fabric to the cloth roller regularly. Texture of a fabric largely depends upon the number of ends and picks per centimeter or inch. This motion determines the number of picks or weft per inch or centimetre and contributes to the uniform texture of the fabrics. It is the work of the weaver for accurately fixing the position of the fell of the cloth before starting a loom.

WORKING PROCESS:-

This positive take-up mechanism is consist of seven wheels. These are;

(1) Ratchet.

(2)  Standard wheel. 

(3) Change pinion.

(4) Stud pinion.

(5) Stud wheel.

(6) Swing pinion and.

(7) Take up roller wheels.

Schematic diagram of 7 wheel take-motion (mechanism).

Actually, the motion is primarily imparted from the sley sword. The sley sword is connected to the sley that gets motions from crank shaft , and the crankshaft gets motion by gearing. At the bottom of sley sword a connecting rod is connected which passes the motion to monkey tail.

The monkey tail is fulcrumed with two pawls , the upper is holding pawl and lower is pulling pawl. These two pawls are mounted easily to ratchet wheel which is connected with the standard wheel by shaft. Over the standard wheel the change pinion is geared. The change pinion is connected with stud pinion by shaft and the stud wheel geared with the stud upon it. The swing pinion is connected with the stud wheel and the cloth take-up roller wheel is geared with swing pinion.

(3) SEVEN WHEEL TAKE-UP MECHANISMS IN COTTON WEAVING:-

The cylinder upon which the woven fabric is wound , is connected to with this wheel by shaft . Now when sley moved one time after one pick insertion the connecting rod passes this motin to monkey tail and as the pawl are fulcrumed with monkey tail, they gets downward motion. By using this downward motion the pushing pawl pulls the ratchet in this position. Finally the cloth roller gets the motion by gear train and thus fabric is wound on cloth roller continuously with the weaving of fabric.

Diagram of seven wheel take-up mechanism in cotton weaving.

Advantages of 7 wheel take-up over 5 wheel take-up.

(1) It can more number of picks in cloth from a little stock wheel by changing two wheel in the train.

(2) It can give even fraction of pick per inch in the cloth.

(3) The number of teeth changed in the change wheel and the number of picks per quarter has been simplified.

Ref:-https://textilelearner.net