Fig. 1 THE MECHANICAL REELING OF SILK.
By this means the thread which is passing from one pulley to the other is stretched by an amount equal to the difference of the winding speed of the two pulleys. In the diagram (Fig. 2) the thread passes, as shown by the arrows, over the pulley, P, and then over the pulley, P¹, the latter having a slightly greater winding speed. Between these pulleys it passes over the guide pulley, G. This latter is supported by a lever hinged at S, and movable between the stops, TT¹. W is an adjustable counterweight. When the thread is passed over the pulleys and guided in this manner, the stretch to which it is subjected tends to raise the guide and lever, so that the latter will be drawn up against the stop, T¹, when the thread is so coarse that the effort required to stretch it is sufficient to overcome the weight of the guide pulley and the adjustable counterweight. But as the thread becomes finer, which, in the case of reeling silk, happens either from the tapering of the filaments or the dropping off of a cocoon, a moment arrives when it is no longer strong enough to keep up the lever and counterweight.
These then descend, and the lever touches the lower stop, T. It will be readily seen that the up and down movements of the lever can be made to take place when the thread has reached any desired maximum or minimum of size, the limits being fixed by suitably adjusting the counterweight.
In the automatic reeling machine this is the method employed for regulating the supply of cocoons. The counterweight being suitably adjusted, the lever falls when the thread has become fine enough to need another cocoon. The stop, T, and the lever serve as two parts of an electric contact, so that when they touch each other a circuit is completed, which trips a trigger and sets in motion the feed apparatus by which a new cocoon is added. In practice the two drums or pulleys are mounted on the same shaft, D (Fig. 1), difference of winding speed being obtained by making them of slightly different diameters.
The lever is mounted as a horizontal pendulum, and the less or greater stress required according to the size to be reeled is obtained by inclining its axis to a less or greater degree from the vertical. An arrangement is also adopted by which the strains existing in the thread when it arrives at the first drum are neutralized, so far as their effect upon the lever is concerned. This is accomplished by simply placing upon the lever an extra guide pulley, L¹, upon the side opposite to that which corresponds to the guide shown in the diagram, Fig. 2.
An electric contact is closed by a slight movement of the lever whenever the thread requires a new filament of cocoon, and broken again when the thread has been properly strengthened. It is evident that a delicate faller movement might be employed to set the feed mechanism in motion instead of the electric circuit, but, under the circumstances, as the motion is very slight and without force, being, in fact, comparable to the swinging of the beam of a balance through the space of about the sixteenth of an inch, it is simpler to use a contact.
The actual work of supplying the cocoons to the running thread is performed as follows: The cleaned cocoons are put into what is called the feeding basin, B1 (Fig. 1), a receptacle placed alongside of the ordinary reeling basin, B, of a filature. A circular elevator, E, into which the cocoons are charged by a slight current of water, lifts them over one corner of the reeling basin and drops them one by one through an aperture in a plate about six inches above the water of the reeling basin.
The end of the filament having been attached to a peg above the elevator, it happens that when a cocoon has been brought into the corner of the reeling basin, the filament is strung from it to the edge of the hole in the plate in such a position as to be readily seized by a mechanical finger, K (Fig. 3), attached to a truck arranged to run backward and forward along one side of the basin. This finger is mounted on an axis, and has a tang projecting at right angles to the side of the basin, so that the whole is in the form of a bell crank mounted on the truck.
There are usually four threads to each basin. When neither one of them needs an additional cocoon, the finger of the distributing apparatus remains, holding the filament of the cocoon at the corner of the basin where it has been dropped. When a circuit is closed by the weakening of any one of the threads, an electromagnetic catch is released, and the truck with its finger is drawn across the basin by a weight. At the same time the stop shown dotted in Fig. 3 is thrown out opposite to the thread that needs strengthening. This stop strikes the tang of the finger, and causes the latter to be thrown out near to the point at which the filaments going to make up the weakened thread are being drawn from the cocoons. Here the new filament is attached to the new running thread by a kind of revolving finger, J, called in France a "lance-bout." This contrivance takes the place of the agate of the ordinary filature, and is made up, essentially, of the following parts:
(1) A hollow axis, through the inside of which the thread passes instead of going through the hole of an agate. This hollow axis is furnished, near its lower end, with a ridge which serves to support a movable portion turning constantly round the axis. (2) A movable portion turning constantly round the axis. (3) A finger or hook fastened on the side of the movable portion and revolving with it. This hook, in revolving, catches the filament brought up by the finger and serves it on to the thread.
Such are the principal parts of the automatic reeling machine. Although the fact that this machine is entirely a new invention has necessitated a somewhat long explanation, its principal organs can nevertheless be summed up in a few words: (1) A controlling drum which serves to give the thread a constant elongation; (2) a pulley mounted on a pivot which closes an electric current every time that the thread becomes too fine, and attains, in consequence, its minimum strength, in other words, every time that a fresh cocoon is needed; (3) electromagnets with the necessary conducting wires; (4) the feeding basin; (5) distributing finger and stops; and (6) the lance-bout.
Our illustration, Fig. 1, shows diagrammatically a section through the cocoon frame and reel. The thread is composed of three, four, or more filaments, and after passing through the lance-bout, it travels as shown by the arrows. At first it is wound round itself about two hundred times, then passed over a fixed guide pulley, and over a second guide pulley lower down fixed to the frames which carry the lance-bouts, then up through the twist and over the smaller of the pulleys, D. Taking one complete turn, it is led round the guide pulley, L, from there round the larger of the pulleys, D, round the second guide pulley, L¹, then back to the large wheel, and over a fixed guide pulley across to the reeling frame. Power is supplied to the latter by means of a friction clutch, and to insure even winding the usual reciprocating motion of a guide is employed. The measuring apparatus is pivoted at F, and by raising or lowering the nuts at the end of the bar the required inclination is given.
We had recently an opportunity of examining the whole of this machinery in detail, and seeing the process of silk reeling in actual operation, Mr. Serrell having put up a complete set of his machines in Queen Victoria Street, London. Regarded simply as a piece of ingenious mechanism, the performance of these machines cannot fail to be of the highest interest to engineers, the reeling machine proper seeming almost endowed with human intelligence, so perfectly does it work. But, apart from the technical perfection, Mr. Serrell's improvements are of great importance as calculated to introduce the silk-reeling industry in this country on a large scale, while at the same time its effect upon India as a silk-growing country will be of equal importance. - Industries.