Practical No.

Experiment Name: To Study passage of warp yarn on a Loomand its Different parts
Introduction:
A loom is a device used to weave cloth. The basic purpose of any loom is to holdthe warp
threads under tension to facilitate the interweaving of the weft threads. The
preciseshape of the loom and its mechanics may vary, but the basic function is the same.
Shuttle loom isa conventional type of loom. In shuttle loom, shuttle carries the weft yarn
through the warp yarn shed to produce fabric in weaving process. The primary and
secondary motions of a loom-
Objectives:
To learn about warp yarn passage of shuttle loom and functions of different parts.
Passage Diagram:
Major Parts of Loom
1. Warp beam -The warp beam, which holds the lengthwise yarns, is located at the back of
the machine and iscontrolled so that it releases yarns to the weaving area of the loom as
needed.

2. Whiproll - This is guide roller which directs the warp threads on their way to the lease
rods and heddles.

3. Leaserods -Another guiding device it is for the warp yarns. These are two sorts of
wooden or glass rods set between the whip rolls and the heddles.Alternating warp
threads can be kept separate by passing over and under these rods.
4. Drop Wire - A warp stop motion element. The electrical circuit completes and loom
stops when a yarn break.
5. Heddles/Healds - A heddle is a wire with a hole or eye in its center through which a
warp yarn is threaded. Thereare as many heddles as there are warp yarns in the cloth,
and the heddles are held in two or moreharness.
6. Harness- A harness is a frame to hold the heddles. The harness position, the number of
harness, and thewarp yarns that are controlled by each harness determine the weave
pattern or interlacing.
7. Pirn/Cop and Shuttle - The filling thread is wound on a bobbin which sets into a shuttle
or bobbin container. As theshuttle passes back and forth through the warp shed, it
releases thread from the bobbin and soforms the filling cloth.
Functions of Shuttle:The shuttle is made of wood which passes from one end of the
loom to the other.Shuttle travels along the wooden sley race and passes between the
top and bottom layers of thewarpsheet.After passing through the warp shed, shuttle
enters a shuttle box fitted at either ends of the loom.It should be noted here that a
shuttle normally weighs about 0.45kgs.

8. Reed - This is inevitably a combination made up of steel wire rods set vertically in a
frame. The spaces between the wires are known as splits or dents and are kept even and
parallel. This is the firstfunction of reed.Its second function is to feed the filling thread
into position. To do this it has to move in a backand forth motion.

9. Breast beam - It is also known as the front rest. It is placed above the cloth roller at the
front of the loom andacts as a guide for the cloth being wound on to the cloth roller. The
front rest together with the backrest helps to keep the warp yarn and cloth in a
horizontal position and also maintain propertension to facilitate weaving .
10. Temples - They divide at the edges of the cloth which supports to maintain
fixed dimension in width.

11. Cloth roller - It is located at the front of the loom . It holds the completed fabric.
 Practical No. 2.
Experiment Name: Study on transmission of motion on tappet loom.
Theory:
Tappets are generally used for heald shedding. Tappet is a type of cam to which a
rotarymotion is given for the purpose of producing reciprocating motion in rods and levers
by slidingcontact. When the rod is to receive a series of lifts, with intervals of rest and thus
forms a shedcalled tappet.
Objective:
1) To learn about gearing diagram or mechanism of tappet loom.
Figure:

Here, motor is the main power source. The machine pulley is connected with motor pulley
by V belt. So, here motor pulley driver. That means, machine pulley is driven by motor
pulley. Crankshaft is connected with machine pulley. The R.P.M. of machine pulley = The
R.P.M. of crankshaft. Bottom shaft gets motion by crank shaft via gear A. Here, A is driver.
The gear C is connected with gear B by shaft. So, the r.p.m. of B = the r.p.m. of C. Then, the
tappet shaft orauxiliary shaft (D) is driven by bottom shaft(C).In tappet loom, a weaving cycle
(that means shedding, picking and beat up) is completed by onerevolution of crank shaft,
the peaking mechanism is control by bottom shaft. Two picking cams are situated in the
outer side of bottom shaft. The two peaking cams are situated opposite side with an angle of
180°. If bottom shaft rotated 360°, 2 peaks occur. That means 2 weaving cyclewill be
completed. So, if bottom shaft rotates one time (360°) the crank shaft must be rotate 2times.
That’s why we can say that, the r.p.m. of crank shaft is 2 times greater than the r.p.m.
of bottom shaft.
Related machine parts:
Motor , MotorPulley , MachinePulley, Gear, Crank Shaft, BottomShaft, Tappet

Construction of the mechanism:

The machine pulley connected with motor by belt.2) Machine pulley is connected with crank
shaft and crank shaft wheel.3) Crank shaft wheel connected with bottom shaft wheel. Which
rotate the bottom shaft.

Working Principle:

When motor rotate, the machine pulley also rotates because motor pulley
connected withmachine pulley by belt.2) Crank shaft wheel also rotates with machine
pulley and crank shaft which transmit the motionto bottom shaft wheel.

Calculation:
R.P.M of motor: 960Motor pulley dia= 3"

Machine pulley dia = 24"

No. of teeth of crank wheel = 38
R.P.M of crank shaft = 960 X (3/24) = 120
R.P.M of bottom shaft = {960 X (3X38)} / (24 X 76) = 60
Result: R.P.M of crank shaft = 120 R.P.M of bottom shaft = 60
 Practical No 3
Aim – To Study the sequence of weaving process
Theory-Weaving is the process of fabric manufacturing by interlacing two sets of yarn called
warp and weft. In the weaving, many developed machines are using in the textile
industries. For example, Air jet loom, Shuttle less loom, Jacquard loom, etc.

Generally, three types of fabric are produced for garments and textile production. These three
types of the fabric manufacturing process are weaving, knitting and non-woven. The
woven fabric is produced by the weaving process. The knitted fabric is produced by inter-
looping by the knitting machine and non woven fabric is produced by applied pressure.

Flowchart of the weaving process:

Yarn preparation in the yarn industry

Yarn doubling and twisting

Winding ( Warp & Weft yarn preparation}

Cone winding/pirn winding

Crilling

Warping

Sizing

Winding to the weaver's beam

Drawing
 ↓

Denting

Looming

Weaving

Take off the fabric role

Fabric inspection

Delivery

1. Yarn preparation: Yarn collects from the spinning industry. But it needs to prepare a
suitable count and package.

2. Winding: Winding requires for preparing suitable yarn package. we know that in the
weaving process two sets of yarn is used. Warp and Weft yarn. Warp yarn wind into a cone
package. But weft yarn wind into prin package for conventional loom and cone package for a
modern loom.

3. Warping: Warping is intended to prepare the beam of the weaver to be installed on the
weaving machine. Warping performs the following operations:
 Create, out of a limited number of warp threads (creel load), a warp composed of any
number of threads with the desired length.
 Arrangement of the above-mentioned threads according to the desired sequence.
The industrial warping process can be accomplished:
 Sectional warping (conical drum or indirect warping).
 Beam warping or direct warping (preparatory beam warping).
4. Sizing: Sizing is the implementation of the adhesive protective layer before weaving in the
warp threads. Warp yarns can resist the complex stresses they are subjected to in the weaving
machine.
5. Weaver Beam Preparation: For long runs of gray fabrics, beam warping is used. As
intermediate stage warper beams are produced that can contain up to 1,000 - 1100 ends. Then
6-12 warper beam threads are merged at the slashing stage and wound on a weaver beam
(loom beam).

6. Drawing: Drawing is done to pull the threads of the warp through the heald wire's eye.

7. Denting: Denting signifies drawing the warp thread through the dent as reed plan requires,
and this more reliably specifies the fabric width and ends per inches.

8. Looming: At the start of the new warp, the tail end of the warp from the exhausted weaver
beam is attached. it is called tying-in. Therefore, the drawing mechanism may be excluded if
each end of the new beam is attached to its consequent end on the old beam. All knots are
pulled through the drop wires, heddles, and reeds after the tying-in process. The loom is
ready for use now.

9. Weaving: Finally Weaving is started and others process will be followed for delivery.
 Practical No. 4
Experiment Name : Study on tappet shedding mechanism.
Theory: Tappets are generally used for heald shedding. Tappet is a type of cam to which a
rotary motion is given for the purpose of producing reciprocating motion in rods and levers
by sliding contact. When the rod is to receive a series of lifts, with intervals of rest and thus
forms a shed called tappet.
Objective:
1) To learn about shedding mechanism of tappet loom.
2) To learn about different parts related to this mechanism.
Figure:

Related Machine parts:

 Tappets.
 bottom Shaft
 Treadle levers
 Fulcrum
 Heald Shaft
 Heald Eye
 Top Reversing Roller
Construction of the mechanism:
1) Tappet achieve motion from bottom shaft.
2) The bowls are placed on the surface off treadle lever.
3) Both treadle lever are connected to lever.
4) Lamb rods, Heald Shaft, Leather Straps are connected to front side of treadle lever.

Working Principle:
1) Tappets are receiving motion from bottom shaft.
2) When tappets rotate the nose of tappet strike on the bowls of treadle lever which move
down with every strike.
3) The treadle lever pulls the lamb rod when tappet strike on it. Due to the pulling operation
the heald shaft also move downward.
4) There is returning spring set up to the top of the loom frame to send back the heald frame
to previous position.
 Practical No. 5

Experiment name:
Study on positive tappet shedding mechanism.

Objectives:

1. To know about the different parts formed this shedding.

2. To learn the mechanism of tappet shedding.

Scope of tappet shedding:

A tappet is a cam having some dwell period which controls the up/down movement of heald
shafts and the time of opening of the shed. Tappets are generally used for heald shedding.
Tappet, cam and wipers are names given indiscriminately to those irregular pieces of
mechanism to which a rotary motion is given for the purpose of producing, by sliding
contact, reciprocating motion in rods and levers. When the rod is to receive a series of lifts,
with intervals of rest, the piece is generally called tappet.

The tappet shedding is the simplest and least versatile shedding motion. The design is
restricted to plain weave, simple twill and simple sateen or satin weave, simple honey comb
and huck-a-back weaves. Any design more than 8 shafts requires dobby loom.

Types of tappet:
Various kinds of shedding tappets are used in industries. They are of two main types:

1. Negative shedding tappet

2. Positive shedding tappet

In negative tappet, the treadle levers are pressed by the tappet, but do not guide it back to
move up whereas in the positive tappet, the bowl moves inside the groves of the tappet and is
positively guided.

Main parts of tappet shedding mechanism:

1. Motor
2. Motor pulley
3. M/C pulley
4. Crank shaft
5. Crank shaft gear
6. Bottom shaft gear
7. Bottom shaft
8. Tappet
9. Connecting rod
10. Heald shaft
11. Top arm

Position of fixation of shedding tappet:

The shedding tappets are may be fixed in different parts of a loom. Namely-
1. Under and over the centre of heald shaft.
2. Under and over one end of heald shaft.
3. Out side the loom framing.

4. Positive tappet shedding mechanism:

In this type of shedding, the heald shaft is raised and lowered by the tappet (Figure
2). The tappet shaft A carries tappet B that has a groove C or track in which a bowl D
is placed. The bowl is connected in turn to a tappet lever E, link rods G, links J and a
heald shaft K. Each tappet is separately connected to a heald shaft through link rods
and tappet lever. F and H are fulcrums for tappet lever and links G, respectively.
5.

Figure 2: Positive tappet shedding mechanism

6. When the tappet is rotated, the bowl is also rotated. According to the shape of the
groove, the bowl is moved up or down or remains still. If the bowl is moved up, the
tappet lever moves to the right through the links G and J and the heald shaft is
lowered. If the bowl is moved down, the tappet lever moves to the left and the heald
shaft is raised. Since the heald shaft is raised and lowered by means of the
mechanism, this tappet shedding is known as positive tappet shedding mechanism.
When the bowl stands still, the heald shaft is in the ‘dwell’ stage.
7. Driving of shedding tappet:
In our loom tappet gets motion in the following way. At first machine pulley gets
drive by belt from motor pulley. Then machine pulley, which is directly joined with
the crank shaft, gives motion to bottom shaft. This crank shaft gives motion to bottom
shaft via gearing. Two tappets are joined with the bottom shaft. So when bottom shaft
moves then the tappets also rotate. When it gets contact with tradle bowl it lifts the
tradle levers and the heald shafts are lifted by tradle levers via links. As this is a
negative shedding tappet the heald shafts are lowered by their own weight.
8. Advantages of tappet shedding:
The main advantages of tappet shedding is that It is robust, simple and cheap, It is
capable of lifting a heavy weight with less wear and tear than other shedding
 mechanisms. It can move heald shafts at great speeds, puts less strain upon the warp,
consumes less power, gives greater output and requires less maintenance.
9. Disadvantages of tappet shedding:
It has some disadvantages also. If the weave is changed, it will be necessary to change
the tappet and the change gear wheel in the counter shaft arrangement. So work
involved in changing the weave is more. The capacity of a tappet to produce a
pattern/weave is very much limited. A maximum of 8 or 10 tappets only can be used.
10. Conclusion:
Tappet shedding mechanism is important for driving loom. It is also important for
fabric design. By this experiment I learn this mechanism. This would be very helpful
in my future life.

Practical No 6

Experiment name: Study on under picking mechanism.

Introduction:
The action of inserting weft yarn through the warp yarns is called picking. Picking is the
second primary motion in weaving. Picking motion propels the weft from one end of the
loom to the other. The term under pick mechanism means the picking stick moves from the
bottom of the box and pivot of the stick is placed below the box. The functions of picking
mechanism are:

1. To deliver the shuttle along the correct flight length.

2. To throw the shuttle at a predetermined speed.

Objects:

1. To know the under picking mechanism.

2. To identify the different parts of this mechanism.
3. To learn the construction of under picking.

Main parts of under picking mechanism:

1. Picking arm
2. Shuttle
3. Picker
4. Bottom shaft
5. Picking cam
6. Treadle lever
7. Picking bowl
8. Angular lever
9. Race board
10. Crank shaft

Features of under picking mechanism:

1. Picker arm is placed under the race board.

2. Suitable for wider loom.
3. Under picking works less smoothly.
4. More direct action.
5. Rough in action.
6. More clean mechanism.
7. Consumes more power.
8. Used for heavy weight fabrics in silk and rayon looms.

Under picking mechanism:

In under picking mechanism a race board is situated over the picking arm. Under picking is
controlled by picking cam which is fixed on the bottom shaft. At first the motion comes from
motor and machine pulley.
 Fig: Under
picking

Then the motion comes in to the bottom shaft and thus picking cam. When picking cam
rotates and its nose portion comes in contact with treadle lever and pushes it then the treadle
lever pushes the angular lever. The picking arm gets motion from angular lever which is
connected with picking arm.

A picker is placed in the picking arm which pushes the shuttle. When shuttle gets motion by
picking arm then shuttle begins to move to and from on the race board. Thus picking is done.

A spring is situated which causes the picking arm and picker to move back after the delivery
of the pick. At the two end of bottom shaft, two picking tappets are fixed. By increasing nose
length picking speed may be increased.

How to increase PPM (Pick per Minute):

1. By increasing motor seed.

2. By increasing the nose shape of picking tappet.
3. By decreasing the length of picking arm.

Uses:
This mechanism is used in all non-automatic cotton looms. It is also used in jute looms.

Conclusion:
This picking mechanism is very important for loom. In the loom under picking is directly
done by picker and picking arm. Again under picking is necessary for weft yarn insertion. So
we should learn about this mechanism very carefully.
 Practical No 7

Experiment name: Study on over picking mechanism.

Introduction:
Picking is the second primary motion in weaving. The action of inserting weft yarn through
the warp yarns is called picking. It may be done by hand or by using devices like shuttle,
gripper, rapier, air jet or water jet.

The functions of picking mechanism are:

1. To deliver the shuttle along the correct flight length.

2. To throw the shuttle at a predetermined speed.

Objectives:

1. To know the over picking mechanism.

2. To identify the different parts of this mechanism.
3. To learn the construction of over picking mechanism

Features of over picking mechanism:

1. Picking arm is over shuttle.

2. Suitable for narrow loom.
3. Higher picks per minute.
4. Less power required.
5. Works more smoothly.
6. Shortening the picking strap and changing the shape of the cam can increase picking
force.

Main parts of over picking mechanism:

1. Picking arm
2. Picking strap
3. Picker
4. Bottom shaft
5. Picking spindle
6. Shuttle
7. Picking cam
8. Vertical shaft
9. Cone
10. Bowl
11. Angular
12. Crank shaft

Mechanism of over picking:

Over picking mechanism is used on cotton and jute loom. It is robust and easy to adjust and
maintain. The spindle is situated over the shuttle box and is essential to guide the shuttle
along the correct path. It is normally set slightly up and slightly towards the front of the loom
and its inner end.

Fig: Over picking mechanism

The back end of the shuttle will thus receive a similar lift at the end of the stroke, so that its
leading end will receive correct delivery down and into the shed. A flexible leather-picking
strap is used to control the picker, which has tendency to stretched slowly in use, and vary
with regard to its elastic property.

The cone over pick motion consists a vertical shaft placed either inside or outside
the loom framing. The shaft serves as fulcrum of the picking arm, it is held against the loom
frame. There is a spiral spring at the picking shaft, which causes the picking arm and picker
to move back after the delivery of the pick.

At the two end of the bottom shaft, two picking cams are fixed. In revolving its nose the
tappet strikes the cone shaped ant frictional roller strut, positively rotates the shaft and causes
the pick to move inward with sufficient velocity to drive the shuttle across the loom. The
timing of the picker begins to move can be attend by turning the picking tappet on its boss.

Uses:
This is used for narrow and fast running looms, weaving light and medium weight fabrics and
for many narrow and wide looms for weaving heavy fabrics.

How to increase PPM:

 1. By increasing motor speed.
2. By setting the cone stud nearer to the picking tappet.
3. By decreasing the picking strap.
4. By altering the position of picking arm towards the center of the loom.
5. By decreasing the length of the stroke of picking tappet.

Conclusion:
The over picking motion is negative one; the exact amount of power is required to drive a
shuttle. By this experiment we learned about the over picking mechanism and how it works.
 Practical No 8

Experiment name: Study on beat-up mechanism in weaving motion.

Objectives:

1. To know about the construction of the beat up mechanism.

2. To know about the drive of the beating-up mechanism.

Introduction:
The beating or beat-up is the third primary motion of weaving. It is also the last operation of
the loom in weaving in which the last pick inserted in the fabric is ‘beat’ into position against
the preceding picks. It consists in driving the last pick of weft to the fell of the cloth. This is
accomplished with the help of a reed fixed in the sley. The sley is given a sudden and quick
movement towards the fell of the cloth by the cranks in the crankshaft. The sleywood runs
from one shuttle box to another, and when at its backward movement, the shuttle travels over
its race.

Fig: Beating-up

There are different types of beat-up mechanism in weaving, depending on several factors. But
mainly, two types of beating is considered in general based on the operating element. One is
crank and crank-arm beat-up (used in shuttle loom), and another is cam best up (mostly used
in the shuttleless loom). However, the related parts of the beating process remain constant
irrespective of whether the main motion comes from crank or cam. The basic difference in
between this is the source of motion of the sley, whereas this sley motion ultimately controls
the overall parameters of beat-up.

Main parts:

1. Crankshaft
2. Reed
3. Crank
4. Sley race
5. Crank arm
6. Sley
7. Reed cap
 8. Sley sword

Fig: Beat-up mechanism in weaving

Description:
The crankshaft gets drive from motor via motor pulley and machine pulley. The crankshaft
has two cranks. These cranks transform the rotary motion into swinging motion. The reed cap
is connected by crank arm to crank of the crankshaft. Again the reed is connected between
reed cap and sley. There is sley sword under the sley that is bolted to the rocking shaft. There
is also shuttle box on the sley. Now the crank gives the swinging motion to the sley by crank
arm. When the sley is moving towards the heald shaft at certain position the shuttle passes
through warp shed. Again when the sley is coming towards the front rest at last position the
reed pushes the last pick to the previous pick of cloth. This is the beating-up motion and the
cloth increases in lengthwise in this way.

Conclusion:
To make a woven fabric interlacement of warp and weft yarns is the main condition. That’s
why beat-up mechanism is a very essential motion for weaving. Proper setting and
adjustment should be taken for this motion.
 Practical No 9

Experiment Name: Study on Positive let-off motion.

Introduction:
The Let-off motion is an arrangement to let the warp from the weaver’s beam at uniform rate
thus maintaining the appropriate warp tension throughout the weaving process.

We know, let-off is a device for controlling the delivery and tension of the warp during
weaving. Let-off mechanism controls the rotation of the beam on a weaving, warp knitting or
other fabric is forming machine where the beam is driven mechanically.

Positive let-off motion is defined as a motion in which the weaver’s beam is turned at a rate
that maintains a constant length of warp sheet between cloth fell and weaver’s beam, the
means of applying warp tension being separate from the beam-driving mechanism.

Types of let off motion:

1. Positive let off motion.

2. Negative let off motion.

Objectives:

1. To know about the different parts formed in this mechanism.

2. To learn the positive let off mechanism.
3. To know the construction of the positive let off mechanism.

Main parts of positive let-off motion:

1. Warp beam
2. Floating back rest
3. Feeler
4. Spring
5. Warm
6. Ratchet
7. Driving rod
8. Collar
9. Reciprocating collar
10. Warm wheel
11. Large beam wheel
12. Adjusting rod

Positive let-off motion:

In the case of negative let-off mechanism the warp is pulled off the beam and the tension is
regulated by slippage in a braking system. In a positive let-off motion, the beam is driven
through a positive mechanism where no slippage takes place. This latter type of mechanism is
seldom used and in most cases the tension is controlled by a mechanism driving the warp
beam, which allows a certain loss of motion (or slippage) whenever the tension increases.
Basically these are crude negative feed back automatic control systems which are related to
controls such as are used in autoleveling during sliver production. These mechanisms are
sometimes considered positive, but in reality they are semi-positive.

Fig:
Positive let-off motion

Above figure shows an example of a positive let-off motion. The warp beam is driven
through a worm and wheel which are turned by a pawl and ratchet (R). The warp passes over
a moveable back rest (B). If the warp tension is reduced, the back rest is moved up under the
influence of the weighted lever (CD). The motion is transmitted through levers to a sheath
which locks the movement of the ratchet wheel and disengages the pawl until the tension
increases again to the normal level under the influence of the cloth take-up.
 Practical No. 10

Experiment Name: Study on Negative Let-off Mechanism.

Introduction:
During each cycle of weaving, the warp sheet has to be released from weaver’s beam in order
that the woven fabric can be rolled up on a cloth roller without changing the location of the
fell of the cloth. This operation is called let-off mechanism.

We can say it briefly, Let-off is to supply warp thread in the weaving zone at a predetermined
rate. If let-off is not uniform, the fabric shall be uneven with variations in pick density and
firmness. Negative let-off is a mechanism for controlling the rotation of the beam on
a weaving, warp knitting or other fabric forming machine where the beam is pulled round by
the warp against a breaking force applied to the beam.

Main parts of negative let-off motion:

1. Warp beam.
2. Beam ruffle.
3. Chain.
4. Machine frame.
5. Weight lever.
6. Pivot.
7. Fulcrum.
8. Weight.

Principle of Negative Let-off Mechanism:

In a negative system of warp let off (below figure), tension in the warp is regulated by
friction between a chain or rope of let-off motion (6) and the beam ruffle (4). This friction
depends on pull applied to the chain or rope by the weighted lever (7), the coefficient of
friction between the chain or rope and the ruffle and the arc of contact between the chain or
rope and ruffle. Because tension on the slack side of chain is Ts, and the frictional force F
between the chain and rope opposing rotation of the beam must balance the tension on the
tight side Tt, the static condition of equilibrium is given by,

F = T t − Ts
Figure: Principle of negative let-off mechanism
In this system the tension of the warp is regulated by the friction between chain and the beam
ruffle. The friction is controlled by dead weight on the weight lever and the distance of
deadweight from the pivot. Heavier the dead weight and longer the distance of it from the
pivot lesser the let-off.

The warp beam dia gradually decreases as weaving proceeds. So it’s necessary to increase the
let-off rate. If the dead weight is kept on the same place, the let-off rate will remain
unchanged. So an experienced worker is required to change the dead weight gradually with
the change of the warp beam dia. As a result irregular tension occurs and the rate of yarn
breakage may increase.

Conclusion:
Negative let-off mechanism is a very simple and manual mechanism. It is suitable for light
and medium weight fabrics. It is mainly used in old looms and for weaving of plain cotton
fabric.
 Practical No 11:

Experiment Name : Study on 7-wheel take up mechanism (Cotton Weaving).

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

Objects:

1. To know about the construction of the 7-wheel take up mechanism.

2. To know about drive of the take-up motion.

Take up motion:
The process of withdrawing fabric from weaving zone at a constant rate and then winding the
woven cloth on the cloth roller with the continuous progress of weaving is called take up
motion.

Types:

(1) According to drive:

 Positive take up.
 Negative take up.
(2) According to motion of the cloth/Rate of take up:
 Continuous
 Intermittent
(3) According to drive given to the cloth roller:
 Direct drive
 Indirect drive
(4) According to number of gear train:
 5-Wheel
 6-Wheel
 7-Wheel
(5) According to brand name:
 Sulzer
 Pickanol
 Toyota

Main parts & Specifications:

1. Sley
2. Changewheel (1-Let)
3. Sleysword
4. Sewing wheel/Pinion (24)
5. Connecting rod
6. Stud/Compound wheel (89)
 7. Monkey tail
8. Stud/Compound Pinion (14)
9. Holding/Catching/Locking pawl.
10. Take up wheel (89)
11. Pulling pawl
12. Take up roller (dia: 15.5 inch)
13. Rachet Wheel (24)
14. Cloth roller
15. Standard wheel (36).

Motion Transfer:
Sley sword to connecting rod. Connecting rod to monkey tail. Monkey tail to pawl. Pawl to
ratchet wheel. Ratchet wheel to standard wheel. Standard wheel to change wheel. Change
wheel to sewing wheel. Sewing wheel to stud wheel. Stud wheel to stud pinion. Stud pinion
to take up wheel. Take up wheel to take up.

Fig: 7-wheel take up mechanism

Working principle:
This positive take-up mechanism consists of seven wheels. These are

i. Ratchet,
ii. Standard wheel,
iii. Change pinion,
iv. Stud pinion,
v. Stud wheel,
vi. Swing pinion and
vii. Take-up roller wheel.
The motion is primarily imparted from the sley sword. The sley sword is connected to the
slay that gets motion from crank shaft and the crank shaft gets motion from motor by gearing.
At the bottom of sleysword a connecting rod is connected which passes the motion to the
monkey tail.

The monkey tail is fulcrum with two pawls: the upper is holding pawl and lower is pulling
pawl. These two pawls are mounted freely to the 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 the stud pinion by shaft and the stud wheel is geared with the stud
pinion upon it. The swing pinion is connected with the stud wheel and the cloth take-up roller
wheel is geared with the swing pinion.

The cylinder upon which the woven fabric is wound, is connected with this wheel by shaft.
Now when the sley moves one time after one pick insertion the connecting rod pass this
motion to the monkey tail and as the pawls are fulcrum with monkey tail they get downward
motion. Using this downward motion the pushing pawl pulls the ratchet wheel one time and
the holding pawl holds 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.

Advantages of 7-wheel over 5-wheel take up mechanism:

1. It can give a larger number of picks per inch in cloth from a small stock of wheels by
changing two wheels in the train,
2. It can give even a fraction of a pick per inch in cloth and
3. The number of teeth in the change wheel and the number of picks per quarter-inch has
been simplified.
Remarks:
By this experiment we know about how to cloth is collected by seven wheel take up
mechanism, motion transfer and advantages 7-wheel over 5-wheel take up mechanism.