Five-Wheel Take-Up

The five-wheel take-up mechanism uses five gears for carrying out the take-up action. The five gears are as follows

1.     Ratchet Wheel- 50-60T

2.     Change Wheel- xT

3.     Compound Wheel- 100-120T

4.     Compound Pinion- 12-18T

5.     Beam Wheel or Take up roller wheel- 60-100T

Here T= teeth and circumference of take up wheel may be 6-16 inches.

                                                             ^{(75T) 1}|----------||||||||||||||||||||||| ^{(take-up roller 15inch)}

                                           ^{(120T) 3}|------------|_{2 (15T)}

                           ^{(50T) 5}|------------|_{4 (x T)}

The above is a representation of a 5 wheel take-up mechanism.

For 1 tooth revolution of the ratchet wheel 1 pick is taken up.

Therefore the number of picks taken up for one revolution of the take-up roller can be found out by doing gearing calculation-taking rpm of take-up roller to be 1.

For 1 revolution of take-up roller the number of picks taken up is

1* (75/15)* (120/x)* 50

= 30000/x

So by dividing with the circumference we can find out the PPI (Picks per inch)

PPI= (30000/x)/ 15

PPI ^{(loom state)} = 2000/x

This is the PPI at loom state.

At grey state, the fabric relaxes and so contracts. So the PPI increase. The contraction is about 1.5 t0 3%. Suppose the contraction is 1.5 % then the PPI of the fabric will be as follows

PPI ^{(grey state)} = (2000/x)* 1.015

PPI ^{(grey state)} = 2030/x

Here the “2030” is called the dividend. If we know the dividend for a certain loom we can easily calculate x, the teeth of change wheel, required to obtain our desired PPI.

In the finished state of fabric further shrinkage. The PPI further increases. The shrinkage is about 5-6%. Suppose the shrinkage is 5% the PPI at finished state will be

PPI ^{(finished state)} = (2030/x)* 1.05

PPI ^{(finished state)} = 2131.5/x

So to summarize, the five wheel take-up mechanism uses one ratchet and 4 spur gears. The change wheel is in driver position. To obtain different PPI we can just use different change wheels in the loom. PPI= dividend/change wheel teeth number.

Usually the five wheel take-up mechanism is used for coarser and heavier fabrics.