9. Picking (Shuttle picking mechanism)

Numerical Problems

1. Calculate the average shuttle velocity from the following particulars:

Width of warp in reed = 1.2 m,

Effective length of shuttle = 30 cm

Loom speed = 240 picks/min Degree of crank shaft rotation available for the passage of shuttle

= 1400

Solution:

From the given data:

R = 1.2 m, L = 0.3 m, P = 240 picks/min, = 1400.

Shuttle velocity v = m/s

2. Calculate the loom speed and weft insertion rate of a loom if the

average velocity of shuttle = 50 Km/h, degree of crank shaft rotation

available for the passage of shuttle across the shed = 1350, shuttle

length = 40 cm, width of warp in reed = 2 m.

Solution:

From the given data:

R = 2 m, L = 0.4 m, = 1400, v = m/s

Loom speed P = picks/m

And WIR = m/min

2

3. Calculate the power required for picking from the following

particulars:

Width of warp in reed = 1.5 m

Effective length of shuttle = 32 cm

Loom speed = 224 picks/min

Shuttle mass = 500 g

Shuttle enters in the shed at 1100 Shuttle leaves the shed at 2450

Solution:

From the given data:

R = 1.5 m, L = 0.32 m, m = 0.5 Kg, P = 224 picks/min, = (2450-1100) =

1350

Power required for picking =

0.306 KW

4. Calculate the power requirement for picking and work done per pick

from the following parameters:

Shuttle mass: 0.5 kg

Reed width: 1.5 m Shuttle length: 0.25 m

Loom speed: 200 PPM

Degree of crank shaft rotation for passage of shuttle: 120

Solution:

R+L = 1.5 m+ 0.25 m

= 1.75 m = 175 cm.

3 25

2

3 ( )10

mp R LP

watt

m = 500 g = 0.5 kg.

So, 3 2

5

2

3 0.5 200 (1.75)10

120P

P = 255.21 watt.

Work done/pick 2 2

4

2

18 ( )10

mp R L

Joule.

3

2 2

4

2

18 0.5 200 (175)10

120

= 765.6 Joule

5. A shuttle of 500 g. mass is uniformly accelerated by the picker of a

cone under-pick motion. The length of the stroke is 15 cm. The final

velocity of the shuttle is 15 m/s. If AB: BC=1:1 then calculate the

force acting on the lug strap.

Solution:

For uniform acceleration, v2 = 2fs

Where v is final velocity, f is acceleration and s is distance travelled by the

shuttle

2 215

2 2 0.15

vf

s

= 750 m/ Sec2

4

Force applied by the picker on shuttle = P = mf = 1

7502 = 375 N

If F is the force acting on the lug strap then

P×2 = F×1

So, F = 750 N.

Force acting on the lug strap = 750 N.