Tertiary motion of a loom

Aims & Objectives of Automation:
To weave perfect cloth or fault free cloth.
To weave large quantities of same cloth or mass
production.
To weave fancy cloth better.
To reduce cost of production.
To improve working condition of the operatives or
reduced mental & Physical strength.
To facilitate continuous weaving.

Features of Automatic loom/ Jacquard loom/ weaving
mechanism:
Automatic weft replenishment (Change):
a) Automatic pirn change.
a. Circular magazine.
b. V-magazine.
c. Box –loader.
d. Loom winder.
b) Automatic shuttle change.
a. Permanent (Replacement of both pirn & shuttle in case of
weft replenishment).
b. Temporary.
1. Weft mixing /patterning.
2. Drop box (4 ×1 or 6 × 1).
3. Circular box (6 × 1).
4. Pick –at –will (4 × 4 / 6 × 6).

Automatic weft stop motion.
Automatic warp stop motion.
Automatic take up & let off motion (positive).
Automatic warp protection or warp protection motion because of
if the shuttle is obsolete to shed then there is necessary of
protection mechanism of warp.
Greater precision of loom parts.
Higher speed of loom
Higher efficiency (ordinary about 70% but in modern it is more
than 80%).
Better quality of fabric.
Lower cost of fabric.
Lower cost of production.
Lower man power required.

When and why weft patterning motion is necessary?
Cross over design is referred as weft patterning. Weft patterning
means how weft way design may produced. The introduction of
yarn of different colour, linear density, or character into the warp
of a fabric is relatively easy to achieve by pre-planning the
position of the bobbins in the creel at the warping stage. Large
differences in yarn linear density or crimp will generally require
that the warp yarn should be supplied from more than one
beam. If more than three beams are required simultaneously on
one loom, problems arise with regard to accommodation and
accessibility and it may even be necessary in some cases to
supply the yarn from individual packages in a creel. But there is
no such loom that contains more than one weaves beam. To
produce cross-over design and weft way design. Then it is
economical to use.

What are the purpose of using weft mixing
motion?
The process which is involved to insert 2 picks, 2
picks alternately for blending or patterning is
known as weft mixing motion.
Purposes:
Insertion of two different kinds or types of
yarns after two picks alternately in a fabric.
To minimize the variation in shades or in
regularity of yarn.
To minimize the variation in count of weft
yarn.
To minimize the tension of weft yarn during
weaving.

Why weft replenishment motion is necessary?
Describe briefly.
The main work of the weaver on non –automatic looms
involved.
a. General supervision and inspection of the yarn, cloth
and machine.
b. Repairing warp and weft breaks.
c. Stopping the loom to replace the weft package when
the yarn on the pirn was almost used up.

In non – automatic loom the down time is high as well
as the production is decreased because the loom,
removing the shuttle, replacing the shuttle in the loom,
restarting the loom and placing a full pirn in the spare
shuttle. In addition to this major drawback, if the loom
was stopped too soon, it would have to be restarted
and then stopped again within a few picks, or
alternatively the pirn would have to be removed with
an excess of yarn that could only become waste. On the
other hand, if the weft would be completely used up
and the weft fork operates so that, on restarting, pick –
finding would be necessary. On these circumstances
there is an obvious need to replace the weft package
automatically and for this purpose weft replenishment
mechanism is involved in loom for the increasing of
loom efficiency and production.

Methods of Designing:
1. Weaving.
2. Printing.
3. Dyeing.
4. Embroidery.
Woven Design: Woven designs are classified as below.
1. Combined effect (Color & weave effect).
2. Structural design (Basic weave & derivatives).
3. Arrangement of warp & weft.
a. Stripe effect.
b. Cross –over effect.
c. Check effect.
4. Colored design (By using colored warp & weft).
a. Stripe effect.
b. Cross –over effect.
c. Check effect.

How can you produce check effect?

How we can produce stripe effect?
In a word we can produce stripe effect by warping. But
we may also produce stripe effect by the following
ways:
1. By employing different colored warp.
2. By employing different kind of warp.
3. By employing different count of warp.
4. By employing different twist of warp.
5. By employing different density in warp sett.
6. By employing different tension in warp sett.
7. By employing different types of yarn.
8. By employing different quality of yarn.
9. By employing different ply of yarn.
10. By employing staple and filament yarn.

How can we produce cross-over effect?
In a word we can produce cross-over effect by using
box motion or weft selection mechanism. We may also
produce cross over effect in the following ways.
1. By using weft mixing motion.
2. By using 2 ×1 weft patterning motion.
3. By using Drop box motion (4 × 1) or (6 × 1).
4. By using circular box motion (6 × 1).
5. By using pick –at –will motion (4 × 4) / (6 × 6)
6. By using weft selection mechanism in modern loom.
In above point no. 1 to 4, only even no. of pick may be
inserted but in No. 5 & 6 any no. of pick may be
inserted.

Weft Replenishment/refill
Feeler: Feelers play an important role in Automation. Weft
replenishment is done by a mechanism making contact with the pirn
by a probing action to detect if yarn was present or not. The action of
probing is given by feelers mechanisms. The principle behind any
feeler action is that. Once every two picks, the presence of yarn on the
stem of the pirn about 4 cm from the pirn butt is investigated. If yarn
is present, the feeder will allow the loom to continue running normally
but if there is no yarn at this point, then the feeder will activate the
start of a change mechanism. On a single shuttle automatic loom the
feeler is mounted at the left –hand side of the loom whereas the
automatic –change mechanism is normally at the right –hand side.

Functions of feeler:
1. To check the presence or absence of yarn for weft insertion.
2. To activate the change mechanism for change or replacement.
Classification of feeler:
1. Mechanical feeler.
a. Side –sweep mechanical feeler.
b. Depth mechanical feeler.
i. Diameter gauge mechanical feeler.
ii. Penetration gauge mechanical feeler.
2. Electrical feeler.
a. Two prong electrical feeler.
b. Photoelectric /photo –cell feeler.
c. Sensor.
3. Electro mechanical feeler.
Above all mechanical and Electrical feeler is most commonly
used.
Shuttle Skewering: Enter the pirn into the shuttle.

Mechanical Feeler
1.Side-sweep mechanical feeler
This mechanism has two parts.
1. Feeler part.
2. Changing mechanism part.

This mechanism is also known as the “midget feeler”. The feeler
blade makes contact with yarn on the pirn when the loom is
nearing its most forward position by penetrating holes in the
shuttle –box front and the shuttle wall. It will be pushed in the
direction of arrow A. (fig: a), because the serrations in the tip of
the blade will have become embedded in the yarn. As the sley
recedes the blade will be returned to its original position by the
spring. When yarn is being withdrawn from the bunch the feeler
blade will slide to the right as indicated the arrow B on the
smooth polished surface of the pirn as the sley is at the forward
position. This will cause the connecting rod to push the bell –
crank lever whose upper arm will then raise the trip lever. The
tripper heel, which is attached to, and therefore oscillates with
the weft fork hammer, will now push the lower arm of the trip
lever and thus cause a sufficient rotation of the change shaft
which therefore activates the changing mechanism. The feeler
blade is returned to its normal position by its spring.

Advantages of Side – Sweep feeler:
Robust construction.
Cheaper.
Used for spun yarn.
Mostly used in normal power loom.
Disadvantages of Side –sweep feeler:
More roughly treatment is on the pirn yarn during
feeling because of the slot in the feeler blade as saw.
The mechanism is totally inactive because of reducing
the elasticity or breaking the return spring for more
using.
The stem of more using pirn is to be rough and then it
loses its activeness.

Depth feeler (Diameter Gauge ):

If there is yarn on the pirn stem adjacent to the bunch,
then the feeler rods downward movement is limited.
But as soon as the yarn has been used, the feeler can
make a complete downward movement and the
projection from the feeler rod will strike the trip lever
to cause a partial anti clockwise rotation of the change
shaft and thus ensure a bobbin change when the
shuttle arrives in the opposite box.
The main weakness of this mechanism is that there is
possibility of yarn damage due to the friction between
feeler cap and yarn on pirn.

Advantages of Depth feeler (Diameter gauge):
For the slippery tendency of feeler along the winding
in direction of yarn. Frictional contact is on to the yarn.
So it is required for filament yarn.
Less possibility of damage in a required /definite
place for hammering on the most area of the pirn yarn.
Less risk of working because of construction facilities.
Disadvantages Depth feeler (Diameter gauge):
Yarn becomes hairy because of hammering on the
most area of the yarn. It is not suitable for spend and
delicate yarn.
For using long time, the expansion of feeler cap may
give wrong direction.

Depth feeler (penetration Gauge):

In penetration gauge feeler pin feeler is used instead of
cap feeler. In this type of depth feeler pin makes with a
pirn opposite a hole in the pirn stem. The presence of
yarn limits the feeler movement but if sufficient yarn
has been used to reveal the hole. Then the feeler will
penetrate the hole and subsequently it activate the
change mechanism. The main weakness of this
mechanism is that the position of the hole in the pirn
must be guaranteed by ensuring that a cut –out in the
butt of the pirn fits on a projection in the shuttle. This
obviously prevent (precludes) the bobbin change but
this type of feeler has been used sufficiently on shuttle
loom and semi –automatic looms.

Advantages of Depth (Penetration gauge):
Less yarn hairiness.
Used in Semi – automatic loom.
Suitable for synthetic yarn.
Disadvantages of Depth feeler (penetration gauge):
Not act for the wrong position of pirn. So possibility
of risk.
The mechanism is not if pirn is not feed in the shuttle
according to the hole during later replacement or pirn
change.
Yarn may damage for the respectively hilling in the
small area.
If feeler pin bents or breaks, it detects wrong or loss
its activeness.

It is an electrical circuit. The current supply is reduced from 440
V. which is much safer and there is no danger to operatives.
The pirn used this mechanism is specially iron coated on the
bunch section. When there is enough yarn on the bunch there is
no contact between the feeler prong and metal of the pirn. But
when there is no contact between the feeler and metal of the
pirn. But when there is no yarn in the bunch then the feeler
prong come into contact with the metal portion of the pirn and
completed the circuit.

The circuit is incomplete until contact is made across the feeler
prongs. This contact is made when the sley is approaching its
most forward position and a metal bond set into the stem of the
pirn adjacent to the butt has been uncovered i.e. yarn is being
withdrawn from the bunch. The completed circuit energizes the
solenoid so that the magnetized core attracts the trip lever into a
post on opposite to a suitable driving, point which is an
oscillating tripper heel and makes ultimately activate the change
mechanism. Since yarn does not conduct electricity, the circuit is
not completed when the metal bond is covered with yarn.

Advantages of Two Prong electric feeler:
Less hairiness of yarn.
It is better for proper direction than
mechanical feeler.
It is less harmful than side –sweep feeler.
Disadvantages of Two prong electric feeder:
Circuit may be uncompleted because of rust in
the point of metal strip where the prong
contacts.
It is not properly acts because of reducing
elasticity or breaking of one or both of the
return spring.
It is not usable for monofilament.

The pirn that is used in this mechanism the pirn stem adjacent to
the butt is specially covered with reflective strip. Incident light
from the source is redirected onto a point that is in line with the
path of the shuttle. Since this system can operate from a
momentary reflexion of a light ray, it is possible to inspect the
pirn by the feeler when the shuttle is in flight across the loom.
When the light ray is thrown back to the feeler head by
uncovered reflective strip on the pirn it passes through a semi –
transparent mirror to the photocell; where it produces a photo –
electric impulse that is amplified by a fully transistorized electric
unit. Which in turn activates an electrical circuit and solenoid is
energized so that the magnetized core attracts the trip lever into
a post on opposite to a suitable driving point which is an
oscillating tripper heel.

Advantages of Photo electric feeler:
It is suitable for spun yarn, delicate yarn and
monofilament yarn because of no component is
contact with package.
Less possibility of risk.
It is used on a large scale in modern m/cs.
Disadvantages of Photo electric feeler:
Costly.
Complex construction.
High power consumption.
Proper performance cannot be get due to the
improper reflection from the reflective strip.
The mechanism may be fully inactive because of rust
on reflective strip.

Mechanical feeler Vs Electrical
feeler
???????????

Weft Patterning
1. By using weft mixing motion.
2. By using Drop box motion (4 × 1) or (6 × 1).
3. By using circular box motion (6 × 1).
4. By using pick –at –will motion (4 × 4) / (6 × 6)

How does weft mixing motion work?
A two- position eccentric shown in fig. governs the
position of a fulcrumed lever. If the connection of the
crank lever to the eccentric is in its highest position
with the bottom box level with the race board but if the
eccentric is turned through half a revolution the lever
will be lowered and the box unit will be lowered to
position the top box level with the race board.

The motion is driven from the bottom shaft of the loom so that
the eccentric will be driven through half a revolution once every
two picks to give the 2 ×2 weft insertion sequence. On the
bottom shaft there is a disc. Into which is set a series of teeth.
The smooth surface of the disc will normally rotate in contact
with a smooth surface on the eccentric but when the teeth in
the disc reach the eccentric. They engage with teeth in the
eccentric. The number of teeth involved in just sufficient to turn
the eccentric through half a revolution before the bottom shaft
disc meets the opposite smooth surface of the eccentric. Two
picks later the procedure is repeated to return the eccentric to
its original position. The motion is timed so that the teeth
engage and thus the box change will take place when both
shuttles are in their respective boxes in the two box unit.

Illustrate the working principle of 6 × 1
circular box motion

The lifting lever A pivoted at B is raised every second pick by a
cam on the bottom shaft I. Passing through slots at the
free end of the lifting lever are lifting hooks C connected at the
rear end of bottom levers D fulcrum at E. To the front
ends of the bottom levers are coupled the draw hooks F which
act on a pegged disc set screwed to outer end of the circular
box. Thus when a lifting hook C is raised by the lifting lever A, it
draws down a hook over the pegged disc and causes the
circular boxes to turn the space of one box, the direction of the
turn being decided by the hook selection

Describe the working principle of 4 × 1
drop box motion.

Stop Motion
Stop motion: A motion is used by which the loom is brought to
an automatic stop immediately as the shuttle fails to reach the
opposite box or in case of any breakage, known as stop motion.

This mechanism is placed at the middle of the side sley race. Fork
is at the groove of sley. Fork is in the up position when shuttle
moves from one box to another box. At the time of picking the
following conditions are appeared.
1. Sley is at the back centre.
2. Slide cam moves to the left.
3. Shuttle moves from one box to another.
4. Fork is in it’s up position.
Centre weft fork motion:

At the time of beating the positions are :
1. Sley is at the forward position.
2. Slide cam moves to the right.
3. Fork is in to down position.

Side-weft fork motion:
It is necessary to have a grid set into the back of the sley
adjacent to the end opposite the forks so that the prongs
can be operated below race board level and it is
impossible for the weft thread to pass underneath them.
It is situated at the starting-handle side of the loom
which is in the left-hand side on modern automatic
looms.

@A cam on the bottom shaft raises a greyhound-tail lever
every two picks and it is timed. So that it causes the weft-fork
hammer to rock towards the front of the loom just after the
fork reaches the grid.
@If the fork is undisturbed it will be pulled by the weft fork
hammer, which will thus cause the whole of the weft fork to
slide towards the front of the loom.
@The knock-off lever will be pushed and will displaced the
starting handle for the loom to be stopped.

Warp Protector Motion ۞
What are the purpose of warp protector
motion?
To protect the warp yarn/ reed/ shuttle in case
of trapping the shuttle in the shed is the
function of warp protector motion. There are
three possibilities in case of shuttle trap.
The reed may be damaged.
The shuttle may be damaged.

Fast reed warp protector motion

Electromagnetic warp protector motion

Advantages of Electromagnetic
1.No banging off
2.Loom stopped immediately
3.No tends to breakage warp

❖Why loose reed motion is not
suitable for heavy fabric??????????

❖Why fast reed motion is not
suitable for light fabric?????????

Tertiary motion of a loom

Tertiary motion of a loom

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Tertiary motion of a loom