# Calculation of Number of Layers of Full Roving Bobbin of Speed Frame

Experiment name:
Calculation of number of layers of the full roving bobbin of speed frame.

Introduction:
Roving is an intermediate product made from sliver and it is normally used as a precursor for yarn. Input to a roving frame is ‘drawn’ sliver, taken from a can filled in the last drawing stage. Sliver is normally drafted by the roving frame to roughly 1 hank/lb and it is then twisted just sufficiently to permit handling before being wound onto a large bobbin.

Essential parts of a roving frame are:

1. A creel, which contains cans from which sliver is drawn to feed the drafting systems,
2. Drafting systems to reduce the linear density of each sliver to that of rovings,
3. Flyers to twist the emerging rovings.
4. Individual winders to take up the twisted rovings onto bobbins.

Objectives:

1. To find out the no of movement of the rack.
2. To find out the no of revolution of upright shaft.
3. To find out the no of revolution of ratchet wheel.
4. To find out the no of layers on full bobbin.

Theory:

1. Total movement of horizontal rack = Total traverse length of one cone drum/Pitch of rack wheel
2. Revolution of upright shaft = Total movement of horizontal rack/No. of teeth of rack wheel
3. Revolution of ratchet wheel = Revolution of upright shaft x (Driver/Driven)
4. No. of layers of full roving bobbin = Revolution of ratchet wheel x No. of teeth of ratchet Wheel x 2

Gearing diagram:

Where,

A= rack wheel
B= rack (pitch= 0.4″)
C= Bevel on upright shaft
D=Bevel in spur ratchet wheel
E= Top spur wheel change pinion
F=Intermediate wheel.
G=Bottom spur wheel change
H=Intermediate wheel
I= gear on ratchet wheel.
J=ratchet wheel
K=upright shaft.

Machine specification:

1. Traverse Length = 26″
2. Pitch of rack wheel = 0.4″
3. No of teeth of rack wheel = 40T
4. No. of teeth of bevel on upright shaft = 18T
5. No. of teeth of bevel on spur ratchet wheel = 21T
6. No. of teeth of top spur wheel changing pinion = 30T
7. No. of teeth of bottom spur wheel changing pinion = 30T
8. No. of teeth of intermediate wheel = 40T
9. No. of teeth of gear on ratchet wheel = 40T

Calculation:

1. No of movement of the rack = 26”/0.4”
= 65

2. No of revolution of upright shaft = 65/40
=1.625

3. No of revolution of ratchet wheel = 1.625 x {(18 x 30 x 40)/(21 x 30 x 40)}
=1.393

4. Total no of layer = No of revolution of ratchet wheel x No of teeth of Ratchet wheel ×2
= 1.393 x 40 x 2
= 111.44
= 112

Results:

1. No of movement of the rack = 65
2. No of revolution of upright shaft =1.625
3. No of revolution of ratchet wheel =1.393
4. Total no of layer =112

Conclusion:
By this practical we learn about the number of layers of the full roving bobbin of speed frame practically. Special thanks to our teacher and his assistance for helping us. I think this practical will be very helpful in my future career. We found a satisfactory result. So the experiment is a successful one.

You may also like: