picking mechanism of shuttle

AKSHAY SEN 18EMBTT201
1
A SEMINAR
ON
PICKING MECHANISM OF SHUTTLE SYSTEM
AT
M.L.V TEXTILE & ENGINEERING COLLEGE
BHILWARA (RAJASTHAN)
"TEXTILE TECHNICAL DEPARTMENT"
Submitted to:
RAJASTHAN TECHNICAL UNIVERSITY, KOTA
SUBMITTED BY: - SUBMITTED TO: -
NAME: - AKSHAY SEN Mr. PRAKASH KUDE
ROLL NO. 18EMBTT201 (Assistant professor)
M.L.V. TEXTILE & ENGINEERING COLLEGE BHILWARA (RAJASTHAN)
(An Autonomous Engineering college of the Rajasthan Govt.)

2
Acknowledgement
It gives me a great sense of pleasure to present the report of B.TECH project
undertaken during B.TECH 4th year. I own special debt of gratitude to Mr.
PRAKASH KUDE department of textile technology, MLVTECH, BHILWARA
for this constant support and guidance throughout the course of my work. His
sincerity thoroughness and perseverance have been constant sources of
inspiration for us. It is only his cognizant effort that my endeavors have been
light of the day.
I also take the opportunity to acknowledge the contribution of DHIRENDRA
SHARMA (principal sir), MLVTECH, and BHILWARA for his full support
and assistance during the project work.
NAME: - AKSHAY SEN
ROLL NO.: -18EMBTT201

3
Abstract
Shuttle loom is one of the oldest machines for weaving of cloth, and is the vital machinery for
power loom industry in India. With this basic loom it is possible to weave nearly all type of
cloths very efficiently. This ancient machine is still used by many weavers in India, so they
face many problems because of high power consumption and more losses of energy, than any
other machinery for this industry to obtain minimum power consumption, detailed analysis of
another auxiliary mechanism called checking, which is also related to picking mechanism, is
required. The mechanism operates by applying brakes to the shuttle, which is at very high
speed, and prepare the shuttle for next cycle of picking mechanism. It uses spring loaded
swells to retard the shuttle. Due to retardation, velocity of shuttle decreases to zero. If these
brakes are not released then picking mechanism needs to generate more power to strike
picker on the shuttle. Hence it is extremely necessary to design and develop a mechanism to
compliment the checking mechanism and to move in the direction of achieving minimum
power consumption. Detailed study is done on the working of checking mechanism of the
present loom. The aim of this project is to develop Picking shaft for better Performance in
twisting moment. The aim of this project is to develop a checking mechanism which releases
the spring-loaded swell at the time of initialization of picking mechanism and load that spring
to break the shuttle when picking mechanism ends.

4
CONTENT PAGE NUMBER
Acknowledgement 2
Abstract 3
introduction of picking mechanism
classification of picking
5
over pick motion
 Cone Over-Pick Mechanism 6
Under pick mechanism
 Cone under pick mechanism
 Side-lever under pick mechanism
 Side-shaft under pick mechanism.
8
Parallel Motions
 Parallel pick method and
 2. Link pick method.
13
Loom timing
15
Results 17
conclusion 18
References 19

5
Introduction
Picking is the second primary motion in weaving. It consists in passing a pick of weft
between the upper and lower lines of a divided warp. It builds up half of the cloth. The shuttle
is the vehicle of weft for picking in the conventional and automatic looms.
Classification of picking-
Types of picking mechanism:
1. Conventional or negative picking mechanism.
2. Unconventional or positive picking mechanism.
Conventional or negative picking mechanism:
In this mechanism, a carrier known as shuttle carries the weft yarn in a package called pirn.
The main function is
1. To deliver the shuttle along the correct flight path.
2. To project the shuttle at a predetermined velocity.
Conventional or negative picking mechanisms are two types
1. Over picking
2. Under picking
Unconventional or positive picking mechanism:
In this mechanism, the weft yarn is inserted through the warp shed directly or positively by
air, water, projectile, needle or rapier. This mechanism is known as positive picking
mechanism.
PICKING - Picking motion is the second primary motion in weaving. In which the weft yarn
is inserted through the warp shed from one side to the other.
Objectives of Picking motion
1. It delivers the shuttle from one shuttle box to the other.
2. To insert the weft yarn through the shed.
3. To throw the shuttle at a predetermined speed

6
over pick motion
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.
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. 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 consist 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.

7
Main Parts:
A. Picking arm B. Picking strap C.Picker D. Bottom shaft E. Picking spindle (F).Shuttle
(G).Picking cam (H)Vertical shaft (I)Cone (J)Bowl Angular (K)Crank shaft
A - Loom bottom shaft
B - Picking cam
C - Picking cone
D - Picking shaft
E - Picking stick
F - Picking band
G - Picker
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 centre of the loom.
5. By decreasing the length of the stroke of picking tappet.

8
Under Pick Mechanism
Introduction:
Objectives:
1. To know the under-picking mechanism.
2. To identify the different parts of this mechanism.
3. To learn the construction of under picking mechanism.
Features of under picking mechanism:
1. Picker arm is placed under the race board.
2. Suitable for wider loom.
3. Under picking work 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.
The types of under pick mechanism are:
I. Cone under pick mechanism
2. Side-lever under pick mechanism
3. Side-shaft under pick mechanism.
Cone under pick mechanism
picking tappet is fixed to the bottom shaft B. The picking tappet has a nose bit C. A cone D
is fixed to a side shaft E, which in turn is connected to a lug strap F. A picking stick G is
looped by the lug strap. The top of picking stick carries a loosely mounted picker H, which
is free to move on a spindle. A shuttle I is in contact with the picker. The bottom of the
picking stick is pivoted and connected to a spring J. A similar mechanism is fitted on the
other side of the loom. But the picking tappet nose is tilted by 180°.

9
A- Picking tappet, B - Bottom shaft, C- Nose, D – Cone, E- Side shaft, F-Lug strap, G -
Picking stick, H- Picker, I-Shuttle, J- Spring and pivot
Working:
When the bottom shaft rotates in the direction shown, the picking tappet also
rotates. When the nose of the tappet comes against the cone, it strikes the cone. This causes a
partial rotary movement of the side shaft. The end of the side shaft thus pulls the plug strap
and hence the picking stick moves inward with sufficient velocity to drive the picker. As the
shuttle is in contact with the picker, it moves out and reaches the opposite box. The picking
stick is returned to its original position by its spring. So, for every rotation of the bottom
shaft, two picks are inserted. For the next pick, the tappet fitted on the other side of the loom
will work and the shuttle will move out of the shuttle box.

10
Side-I ever under pick Mechanism
Construction: -
A side-lever under pick mechanism is, A circular disc A is fixed to the bottom shaft B. The
disc contains slots. A bowl C is fixed in one of the slots. Side lever D, which is below the
disc, carries a picking shoe E at the centre and is connected to a bracket F and spring G at the
back end. The bracket acts as a fulcrum for the side lever. A guide H is used to guide the side
lever during its motion. The lower front end of side lever touches an elbow J, which carries
the picking stick K. A picker L is loosely mounted on the picking stick. The elbow is
connected to a coiled spring M, which is in a housing bracket. The elbow is connected at the
bottom to a rocking shaft N. A buffer is fixed to the side frame of the loom and a check strap
is in the slot of a bracket provided below the shuttle box. The picker is kept in contact with
the tip of the shuttle O, when it is in the shuttle box. the bowl on the circular disc is shifted by
180 degrees. So, for the first 180 degrees the rotation of the bottom shaft, the shuttle is
delivered from one side and for the next 180 degrees, it is delivered from the other side. Thus,
one revolution of the bottom shaft introduces two picks.
(A) Circular disc (B) - Bottom shaft (C)- Bowl (D) - Side lever (E) - Picking shoe (F) -
Bracket (6) - Spring (H)-Guide (J)-Elbow, (K)- Picking stick, (L)-Picker, (M)- Spring, (N) -
Rocking shaft, (O)- Shuttle

11
Working: -
When the bottom shaft rotates in the direction shown in the figure, the bowl also rotates with
the circular disc. As the bowl comes against the shoe, it strikes the shoe and thus lowers the
forward end of the side lever. This in turn hits the elbow down and the picking stick moves
towards the centre of the loom. The picker, loosely mounted on the stick, moves and pushes
the shuttle into the shed. At the end of the motion the stick and the side lever are returned to
their original positions by their spring respectively. A similar arrangement of parts is
provided on the opposite side of the loom to enable the return of the shuttle for the next pick.
When the pickings parts on one side of loom are in action, those on the other side are out of
action. The check strap is used to reduce the speed of the shuttle and prevent it from
rebounding. The guide-bracket guides the lever while it is moving. There is also a buffer to
absorb the shock create during the motion of the picking stick.
Side shaft under pick mechanism
Construction: -
disc A is fixed to the bottom shaft B. A bowl C is fixed in the slot of the disc. Below the
disc, a curved shoe D is connected to a side shaft lever E. The side lever is in turn connected
to a lug strap G by a connecting lever F. A picking stick H is in the loop of the lug strap G.
The top of the picking stick carries a loosely mounted picker I. The shuttle K is in contact
with the picker. The bottom of the picking stick is pivoted at L and connected to a spring J. A
similar mechanism fitted on the other side of the loom. But the position of the bowl on the
disc is titled by 180 degree.

12
A- Disc B - Bottom shaft C - Bowl D-Shoe E- Shoe-shaft lever F- Connecting lever G - Lug
strap H-Picking stick I- Picker J- Spring K - Shuttle L – Pivot
When the bottom shaft rotates in the direction shown, the disc also rotates in the same
direction. When the bowl comes against the shoe it strikes the shoe. This causes the side shaft
lever to depress and pull the lug strap through the connecting lever. So, the picking stick is
pulled inward with sufficient velocity to drive the picker. As the shuttle is in contact with the
picker, it is pushed. The shuttle thus reaches the opposite box. The picking stick and side
shaft lever are returned to their original positions by return springs. For the next pick, the disc
on the other side of the loom will work and the shuttle will come out of the opposite box.
Thus, for one rotation of the bottom shaft, two picks are inserted. The timing of picking can
be altered by changing the position of the bowl in the disc slot. The strength of pick can be
altered by raising or lowering the lug strap. By lowering the lug strap the strength of the pick
is increased and vice-versa.

13
Parallel Motions
Necessity for parallel motions: - In under pick mechanisms, the picker is mounted loosely
on the picking stick. As the picking stick moves with its fulcrum at the bottom, the picker
adjusts itself with the shuttle box and moves in a straight path. So, there is a greater wear and
tear of the picker and it is not suitable for highspeed looms. The stick moves along an arc if
the picker is fixed rigidly. So, the shuttle could fly off. Automatic looms of the wider type
and heavy looms require more power for picking. In these looms, it is necessary to have
higher strength of pick. So, the picker is fixed tightly on the picking stick. Hence to get a
straight horizontal path for the picker and to improve the life of the picker the parallel
motions were introduced.
Principle: -
The principle of parallel motion involves varying the height of the fulcrum of the picking
stick during picking. So, the picker will follow a straight and horizontal path.
Methods: -
There are two methods of achieving horizontal movement of the picker. These are:
I. Parallel pick method and
2. Link pick method.
I. Parallel pick method: -
This is also called Steam’s parallel motion. This method was invented to rectify the above
defects in the under-pick mechanism.
Steam’s Parallel Motion: -
This motion consists of mounting the picking stick A on a curved shoe B that rocks evenly
on a flat surface C so that the top of the stick does not move along the arc of a circle but
maintains a straight line. The picker D is also screwed firmly to the top of a stick so that the
spindle and box guide plates are removed, C is the flat surface fixed parallel to the loom-
rocking rail E at the foot on the sley. The shoe B is slotted at the front to engage with the
projection F. A lug strap G drives the picking stick. A metal bracket drum J is coupled to the
picking stick. The strap K returns the stick after picking. The curved shoe changes the
fulcrum of the picking stick as it advances to move parallel to the base of the box. So, the
shuttle L moves in a horizontal plane. After this the picking stick comes back to its original
position by means of the strap K and the coiled spring I. T parts

14
How to increase PPM:
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.

15
Loom Timing: -
Loom timing is defined as relative chronological sequences of various primary and secondary motions are
expressed in terms of angular position of crank. The loom timing is shown
Loom timing diagram for shuttle loom (early shedding)
Sley Motion
 0°: Beat-up takes place and sley occupies its forward most position
 180°: Sley occupies its backward most position
 0°-180°: Sley moves backward
 180°-360°: Sley moves forward
Picking and Checking
 80°-110°: Picking mechanism operates
 105°-110°: Shuttle enters in the shed
 240°-250°: Shuttle leaves the shed
 270°: Shuttle strikes the swell in the shuttle box
 300°: Shuttle comes to rest

16
Shedding (for early shedding)
 30°: Shed is fully open
 30° -150°: Heald dwell (shed remains fully open)
 150° -270°: Shed closes
 270°: Shed closed or shed level
 270° -30°: Shed opens again (in opposite direction)
Shedding (for late shedding)
 120°: Shed is fully open
 120° -240°: Heald dwell (shed remains fully open)
 240° -360°: Shed closes
 360°: Shed closed or shed level
 360° -120°: Shed opens again (in opposite direction)
The operations have been delayed by 90 0 in case of late shedding.
Take-Up
 0° -10°: Take-up (intermittent type)

17
RESULTS
Picking motion is the second primary motion in weaving. In which the weft yarn is inserted
through the warp shed from one side to the other.

18
CONCLUSION
Conclusion the Shuttle loom machine face many problems because of high power
consumption and more losses of energy, than any other machinery for this industry. To
improve functionality of shuttle loom various parameters are identified for picking and
checking mechanism. Both picking and checking are interrelated with each other. Here,
checking of the mechanism is developed from scratch to reduce picking force transmitted by
picker to shuttle. To also improve the production rate, it is mandatory to increase the speed of
picking mechanism, which plays main role in weaving of the fabric. The Picking and
Checking mechanism directly affected Quality of fabric.

19
References
 Horrocks, A. Richard; Anand, S. C., eds. (2000). Handbook of technical textiles.
Woodhead Publishing. pp. 87–88. ISBN 978-1-85573-385-5.
 "Leclerc Loom Options: Flying Shuttle Option". Camilla Valley Farm Weavers'
Supply. Retrieved 9 February 2009.
 Harling, Nick. "John Kay 1704-1780: Inventor of the Flying Shuttle". Cotton
Town. New Opportunities Fund. Archived from the original on 28 September
2007.
 Broudy, Eric (1993). The Book of Looms. University Press of New England.
pp. 148, 151. ISBN 0-87451-649-8.
 "Flying Shuttle" (PDF). Master Weaver (60). November–December 1961.
 Hills, Richard (1990). "Textiles and Clothing". In McNeil, Ian (ed.). An
Encyclopaedia of the History of Technology. Taylor & Francis. pp. 821–
822. ISBN 0-203-33017-X.
 WEAVING TECHNOLOGY-II
 BY SHRI G.SUKUMARAN NAIR, JUNIOR LECTURER (TEXTILES), IIHT, SALEM.
o principal of weaving &weaving mechanism part 1&2 author R mark & ATC
robinson NN banerjee
 weaving woven fabric production 1&2 author talukdar azgaonkar and
sriamulu
 NCUTE publications

picking mechanism of shuttle

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