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3.3. The contrivance for untwisting of thread

The “moulinet” is twisted of 6 or 12 cotton threads. More thin threads are needed for lace making. They can be made by splitting (untwisting) the “moulinet”.
Manual untwisting does not prove to be simple as it seems at first sight. It becomes just clear that an operator ought to have the third and fourth hands. In other words this work can not be done without an assistant.
Splitting technique consists of three operations:
- pull out of the clew a part of “moulinet”, untwist it and split at three flows of two-,  three- or four-fold thread;
- rewind split threads around three intermediate spools keeping equal tension;
- stop splitting every time when the next part of “moulinet” is being pull out of the clew.
It ought to keep strictly the rule – avoid excessive touching the thread by fingers to save its cleanness.
The problem of keeping thread tension constant arises because of growing difference in length of untwisted threads. The greater is difference, the less is tension. The state of emergency takes place. One must stop splitting and eliminate thread sag in the emergence channel by means of additional rotation of the spool. Of course it is impossible in this case to avoid needless touching the thread.
Authors of the book suggest method of splitting that provides automatic compensation of thread sag using gravity strength. The principle can be seen on the cinematic scheme (Fig.3.4).

Mass of the clew 1 is enlarged up to 150 grams (0.33 pound) with a metallic ball inserted into it. The clew works as a plumb. It hangs at pulled out thread (L ? 1.5 meter or L ? 5 foots) and rotates untwisting the “moulinet”.
The comb 2 splits the “moulinet” at three threads. The split thread moves towards the comb 3 going under the roller 4 that is pulled down with gravity strength F1.
The split thread moves farther above roller 5 and under roller 6, both being set on the disk 7. The gravity strength F2 turns the disk 7 clockwise.
It is to be noticed that using two different compensators 4 and 7 is not obligatory. The matter is both realize the same principle. On this reason it would be possible to change the disk compensator 7 with falling roller like the roller 4. However author saved both compensators as they are to demonstrate possible variants of tension controlling.
After the roller 6 the split thread goes through a guiding comb 8 to the intermediate spool 9 set on the main roller which is rotated by hand of an operator i.e. a lace maker.
If tensions of three threads are equal, the balance of all strengths (gravity and friction) takes place. The roller 4 moves up to level of the combs 2 and 3; centers of the rollers 6 and 7 are at the horizontal line.
As soon as one of three threads becomes longer then other two, thread tension relaxes and the balance of strengths comes at other position of rollers. The roller 4 falls and the disk 7 turns clockwise. Movement of rollers stops when tension restores at this channel and becomes equal tension in other channels.
When the current piece of the “moulinet” is split, it is necessary to stop movement of disks 7 and spools 9. The pause is needed to pull the next “moulinet” piece out of the clew 1 and to untwist it.
There are many methods to work out a cinematic scheme according to the compensation principle. One of methods is presented on Fig.3.5 (front view).
Three units are placed on the platform 1:
- the unit 2 with three spool to wind split threads;
- the unit 3 with guiding forks to lay coil on spools;
- the unit 4 that contains three disk compensators and the brake mechanism for the disks.
The frame 5 is attached to the platform 1. Guiding combs 6 and 7 are set at the frame 5.
Three spools are set at the main roller. Ends of the roller are mounted into the ball bearings attached to posts.
The fly-wheel 8 is set at the right end of the main roller. The wheel has a handle to rotate it (Fig.3.6, side view). The brake mechanism of the fly-wheel consists of the pusher 9 having a rubber strip at the top. The pusher falls down due to gravity when the split process is going. If the process is stopped the pusher is lifted and pressed to the fly-wheel rim fixing position of the wheel.
The brake mechanism of the disk compensator contains the metallic plate that rotates around its longitudinal axe. Flat spring is set under every disk. Rubber strip is stick to the end of the strip. Three disks are braked simultaneously when the plate is turned pressing the springs and strips to the disks. The disks and the fly-wheel are to be relaxed to continue the split process.

Tension of the thread is controlled with levers 10 and 11. Both are joined to the platform 1 by means of hinges. The lever 10 is hung to the compensator disk with a flexible cord. The cord is attached to disk at the point near to the left roller. Strength F2 depends on own lever weight and weight of additional plumb 12.

The lever 11 hangs with roller on the thread between the combs 6 and 7. Strength F1 depends on weight of the lever 11 only. Depth of the lever falling must be limited with a cord tied to the platform 1.
The lever 10 is set by an operator at horizontal position when the next part of the “moulinet” is being pulled out of the clew. The pusher 9 moves upwards and brakes the fly-wheel 8. At the same moment the disk compensators are to be braked and three levers 11 are to be lifted. When untwisting of the “mouline” is finished, the levers and the disks relax to control the thread tension.
The unit 3 on Fig.3.5 is not obligatory but it proves to be useful since coils on the spools would be set in layers. If the unit is absent, the thread is wound as a shapeless hillock. Special guiding forks are necessary to lay the thread smoothly.
Ideally three forks must do synchronous reversionary movements along spools keeping constant speed. Alike mechanism is in any sewing machine. It can not be repeated in domestic workshop, however it is possible to do some approximation to the ideal.
A designer-amateur is capable to make mechanism that transforms gyration movement to progressive motion of guiding forks: crank-swaying mechanism (Fig.3.7) or eccentric disk mechanism (Fig.3.8).

Unfortunately both mechanisms lay irregularly the thread coils along the spools. Density of coils falls from the ends to the middle of the spool (Fg.3.9).
In any case the irregularity is practically the same in equal conditions. The crank-swaying mechanism proves to be more complex than the eccentric one. Besides it has principal drawback – the crank sometimes stops at the dead points. At the points it must be pushed to continue movement. The eccentric mechanism is simpler and more reliable.
Moreover the form of the eccentric can be corrected to get more regular lays of the thread along the spool.
The device for laying coils consists of two units:
- the reducer;
- the block of guiding forks.

The reducer is to provide the speed of the eccentric rotation at 30 to 40 times less than the speed of the spools rotation. The principles of reducing are well known. The main types of reducer are:
- the wheel pairs tied with the belt transmission;
- the friction wheel pairs;
- the cylindrical and conical tooth gearing;
- the worm gearing.
The reducer under consideration is notable of the small power. On this reason it can be produced without the special equipment using ready fabricated wheels. In amateur conditions it is easy to build the reducers of the first three types.
The belt transmission is the simplest in manufacture. It is unpretentious and condones all inaccuracies of details. If ready pulleys are not accessible, they can be cut of 10-mm ply-wood. The groove is to be made on the rim using the round file. The rubber rings are suitable for transmission. The ring may have round, square or rectangular section.
The friction pair seems to be more complex. One of the sheaves can be made of a hard material (plastic, wood, metallic). It must have an ideal cylindrical surface. It is better to find ready wheel. The second wheel must have a soft rim to provide a good traction. The rim can be made of rubber or flexible plastic. The skate-board rollers would be an ideal pair. The tooth gears can be adopted from different sources including children’s design sets, big clock mechanism etc.
An example of the cinematic scheme of the reducer is shown on Fig.3.10.

Three receiving spools are set on the main shaft 1. The fly-wheel 2 is attached on the right end of the shaft. The left end of the shaft is bound with the sheave 3 by means of the belt 4. The sheave 5 is set on the same shaft together with the sheave 4.
The second sheave 6 of the belt pair 5-6 at the same time forms the friction pair together with the wheel 7. This pair is intended to perform two functions:
- to transfer the gyration to the vertical plate that is parallel with the gyration axe of the main shaft 1;
- to rotate the wheel 8 that carries the eccentric 9 and provide reversible swaying of roller 10.
The wheels 7 and 8 have the general gyration axe. The eccentric 9 is attached to the wheel 8. The bearing roller 10 is pressed to the rim surface of the eccentric 9 so that the rotation axe of the roller 10 reversible sways at the plate of the eccentric gyration.
Two belt transmissions reduce gyration rate of the fly-wheel 2 at 40 times. Since the friction pair formed with equal wheels, the total reduction is 1:40.
Fig.3.11 illustrates the transformation of uniform gyration into reversible swaying movement.

When the split threads are wound to three spools, the wheel 8 rotates clockwise keeping constant gyration rate. The bearing roller 10 is pressed to the eccentric 9 with the spring 11. The eccentric 9 make the roller 10 to sway together with the lever 12. The cord 13 tied to the lever 12 pulls the control rod 14 that moves levers of guiding forks 15, 16, 17. The threads goes through the forks and periodically change direction of movement along the spools.
The general view of the contrivance for untwisting of the “moulinet” is shown on Fig.3.12 and Fig.3.13.

All basic units are seen on Fig.3.12 including:
- the main shaft with three spools and the fly-wheel;
- the reducer (on the left from the shaft);
- the eccentric mechanism and three guiding forks;
- three disk compensators and the brake lath in front of the disks;
- the frame and two combs on it;
- three lever compensators that can be seen through the frame;
- the box intended to save the clew; besides the clew there are three spools saving the split thread.
Fig.3.13 shows the following units:
- the brake of the fly-wheel;
- the lever compensators under the combs;
- the levers tied to the disk compensators with the cords.