The price of a machine having 130 needles, and of consequence 260 pincers or fingers and thumbs to lay hold of them, is 5000 francs, or 200l. sterling; and it is estimated to do daily the work of 15 expert hand embroiderers, employed upon the ordinary frame. It requires merely the labour of one grown-up person, and two assistant children. The operative must be well taught to use the machine, for he has many things to attend to: with the one hand he traces out, or rather follows the design with the point of the pantograph; with the other he turns a handle to plant and pull all the needles, which are seized by pincers and moved along by carriages, approaching to and receding from the web, rolling all the time along an iron railway; lastly, by means of two pedals, upon which he presses alternately with the one foot and the other, he opens the 130 pincers of the first carriage, which ought to give up the needles after planting them in the stuff, and he shuts with the same pressure the 130 pincers of the second carriage, which is to receive the needles, to draw them from the other side, and to bring them back again. The children have nothing else to do than to change the needles when all their threads are used, and to see that no needle misses its pincers.
This machine deserves particular attention, because it is no less remarkable for the happy arrangement of its parts, than for the effects which it produces. It may be described under four heads: 1. the structure of the frame; 2. the disposition of the web; 3. the arrangement of the carriages; and 4. the construction of the pincers.
1. The structure of the frame. It is composed of cast-iron, and is very massive. [Fig. 371.] exhibits a front elevation of it. The length of the machine depends upon the number of pincers to be worked. The model at the exposition had 260 pincers, and was 2 metres and a half (about 100 inches or 8 feet 4 inches English) long. The figure here given has been shortened considerably, but the other proportions are not disturbed. The breadth of the frame ought to be the same for every machine, whether it be long or short, for it is the breadth which determines the length of the thread to be put into the needles, and there is an advantage in giving it the full breadth of the model machine, fully 100 inches, so that the needles may carry a thread at least 40 inches long.
Disposition of the piece to be embroidered.—We have already stated that the pincers which hold the needles always present themselves opposite to the same point, and that in consequence they would continually pass backwards and forwards through the same hole, but the piece is displaced with sufficient precision to bring opposite the tips progressively of the needles, every point upon which they are to work a design, such as a flower.
[Fig. 371 enlarged] (465 kB)
![[Fig. 371 enlarged]](#1185752912146279659_lg0431.png.id-3913756314304957360.wrap-0.html.html){kind=link}
The piece is strained perpendicularly upon a large rectangular frame, whose four sides are visible in [fig. 371.]; namely the two vertical sides at F F, and the two horizontal sides, the upper and lower at F′ F′′. We see also in the figure two long wooden rollers G and G, whose ends, mounted with iron studs, are supported upon the sides F of the frame, so as to turn freely. These form a system of beams upon which the piece destined to receive the embroidery, is wound and kept vertically stretched to a proper degree, for each of these beams bears upon its end a small ratchet wheel g, g; the teeth of one of them being inclined in the opposite direction to those of the other. Besides this system of lower beams, there is another of two upper beams, which is however but imperfectly seen in the figure, on account of the interference of other parts in this view of the machine. One of these systems presents the web to the inferior needles, and the other to the upper needles. As the two beams are not in the same vertical plane, the plane of the web would be presented obliquely to the needles were it not for a straight bar of iron, round whose edge the cloth passes, and which renders it vertical. The piece is kept in tension crosswise by small brass templets, to which the strings g′′ are attached, and by which it is pulled towards the sides of the frame F. It remains to shew by what ingenious means this frame may be shifted in every possible direction. M. Heilmann has employed for this purpose the pantograph which draughtsmen use for reducing or enlarging their plans in determinate proportions.
b b′ f b′′ ([fig. 371.]) represents a parallelogram of which the four angles b, b′, f, b′′, are jointed in such a way that they may become very acute or very obtuse at pleasure, while the sides of course continue of the same length; the sides b, b′ and b, b′′ are prolonged, the one to the point d, and the other to the point c, and these points c and d, are chosen under the condition that in one of the positions of the parallelogram, the line c d which joins them passes through the point f; this condition may be fulfilled in an infinite number of manners, since the position of the parallelogram remaining the same, we see that if we wished to shift the point d further from the point b′, it would be sufficient to bring the point c near enough to b′′, or vice versa; but when we have once fixed upon the distance b′ d, it is evident that the distance b′′ c is its necessary consequence. Now the principle upon which the construction of the pantograph rests is this; it is sufficient that the three points d, f, and c be in a straight line, in one only of the positions of the parallelogram, in order that they shall remain always in a straight line in every position which can possibly be given to it.