The present Machine then, is a superior kind of throstle, the construction of which will be understood, by spinners, from the annexed figures, [5 and 6] of [Plate 40]. As the principal difference between the former machines and this, resides in the toothed wheel by which it’s spindles are turned, we shall begin this description by adverting to it: A B is that wheel, cut, at present, into 800 inclined teeth, and working with pinions of 11 teeth, one of which, with it’s spindle, is shewn at a b, [fig. 6]. The revolutions, therefore, of these spindles to one of the wheel, are 72.7272, &c.; and since the latter, in spinning, makes from 60 to 70 turns per minute, the spindles run at the rate of 5000 turns in that time, and might do more if desired by the spinner. In a word, the useful speed depends on the size and weight of the spindles, the flyers, &c.
Immediately above and below the wheel A B, are two rings of cast iron, to which are screwed rims, either of wood or metal, destined to hold the steps and bolsters of the spindles, as is usual in a throstle, with the difference of the circular form, which the wheel of course requires; and the relation of which, to the rollers, is shewn at a b, [fig. 5], being a plan of this Machine. Returning to [fig. 6], the next object upward is the roller-beam, (cast hollow for lightness) the form of which is that of an octagon, with two brackets c d, by which it is fastened to the pillars E F: these, in their turn, being connected with the top and bottom cross-pieces (G H, I K) so as to make up the frame, properly so called. All these parts are placed (in section) similarly to those usually composing the throstle; and the copping motion is produced by the curve f, driven by an endless screw on the shaft h f, and acting on the slide f g, and through it on the ring of which the square i is a section: and on whose iron plate, in fine, the bobbins drag, as they do in the throstle. In the Machine before us, the rollers are driven by two side-shafts h f, which take their motion either from a train of spur wheels placed above the traverse G H, or by bevil wheels from two small shafts, coming under that traverse from the central shaft L M, to those h f, and acting on the rollers by means of the bevil wheels f m, seen in the [figures]. Now, the rollers are contained in eight heads—1, 2, 3, 4, 5, 6, 7, 8, each of which has it’s speed wheels in the angles n o, &c. and receive their motion from six sets of bevil wheels q, &c. which propagate the motion round each half of the Machine, from the points m and p respectively.
Above this roller-beam, is the creel-ring N O, which (either in one or two rows) receives the sixty roving bobbins that supply the sixty spindles, of which the Machine is composed: and whose threads pass under the eight sets of rollers—one thread being suppressed in each of the heads—1, 4, 5, 8, on account of the columns. (This, at least, is the arrangement I prefer; but some of the Machines have been made with eight threads in all the compartments.) Finally, in this frame G H, I K, is placed a ring P Q, (of glass or bright metal) over which the rovings are thrown before they are put in the guides behind the rollers; so that the route of a thread in the act of being spun, is shewn in [fig. 5], by the line P R, S b, where it meets the bobbin on the spindle a b, before mentioned.
It may be observed here, to prevent ambiguity, that the guide-boards, with their hooks, are placed below the octagon roller-beam q n o, &c. as they are in the common throstle; being, each, 1⁄8 of the whole circumference, and of a circular form on the outside, reaching, by these hooks, to the point S, so as to hold the thread just over the centre of the spindles as at a b, [fig. 6]. Considering this as a commonplace subject, I have not attempted to draw these boards, since their form and position would occur to every constructor: and this is the reason also, why I have given only the section of the copping ring i, [fig. 6]: nor at all shewn the top rollers—nor the detail of the creel—on all which topics, opinions vary considerably, while the things themselves are really of minor importance.
There is, however, in my Patent System, something which I think important, and which, therefore, I have sketched near Q, [fig. 6]. If w x be there considered as the second communication shaft, a wheel z is put on it, of that kind which is calculated to work in a certain geering chain, called in French chaine de Vaucanson, (from the name of it’s inventor); and further, similar wheels (y) are connected with all the pins on the creel, round which the chain is carried from the wheel z, till it comes to it again. The consequence is, that all the wheels (y) are turned by that chain, so as to untwist the roving while the spinning rollers draw it off the bobbins: and this is so, because, in my Patent System, the rovings are over-twisted, in order to admit their being made very fast, without the danger of breaking. This then, completes my Patent Eagle, formed, on the right hand of the [figure] so as to use over-twisted roving; and on the left hand, so as to spin common roving in the usual manner. In both cases, the motion of the spindles by geering, ensures a mathematical twist, and thus produces yarn better than common; whence also it’s fineness can be carried much farther than on a common throstle. It need hardly be added, that these spindles are stopped and set in motion by the mechanism described in my second Part, at [fig. 1], [Plate 19]: and there mentioned as “a [Machine] to set-on and suspend rapid motions.”