As long as the friction disc x′ remains at the same height, the pulley g′ derives its motion from the same circle of the said disc, and the up and down motion of the copping beam is also uniform. But when that disc ascends so as to describe with its edge a small circle upon the face of g′, its motion must become proportionally more slow. This is the method, or principle of retarding the copping motions of the bobbins. It has been shown, however, that the rotation of the bobbins should be also retarded in a progressive manner. This object is effected by means of the cone k′, which, as the band n′ progressively approaches towards its smaller diameter, drives the pulleys or whorls q of the bobbins with decreasing speed, though itself moves uniformly quick with the shaft c′. To effect this variation, the cone is shifted lengthwise along its shaft, while the band running upon it remains continually in the same vertical plane, and is kept distended by the weight of the pulley o′. The following mechanism serves to shift the cone, which may be best understood by the aid of the [figures 340.], [341.], and [337.] A long cast iron bar m3, which bears two horizontal projecting puppets, o3 o3, is made fast to the front upright face of the copping beam A. Through the above puppets a cylindrical rod n3 passes freely, which is left out in [fig. 337.], that the parts lying behind it may be better seen. Upon this rod there is a kind of fork, p3 p3, to which the alternating rack bars q3 are made fast. The teeth of these racks are at unequal distances from each other, and are so arranged, that each tooth of the under side corresponds to the space between two teeth in the upper side. Their number depends upon the number of coils of roving that may be required to fill a bobbin; and consists in the usual machines of from 20 to 22. The rod n3 may be shifted in the puppet o3, like the fork p3 of the rack-rod, upon the rod n3, and along the surface of m3, where two wings u3 u3 are placed, to keep the fork in a straight direction. Upon the bar m3, there are the pivots or fulcra of two stop catches w3 x3, of which the uppermost presses merely by its own weight, but the undermost by means of a counterweight y3, against the rack, and causes them thus to fall in between the teeth. In [fig. 341.], v3 shows the pivot of the catch or detent w3 by itself, the detent itself being omitted, to render the construction plainer. A pushing rod l3, upon which there is a pin above at s3, that passes behind the rack rod, between this and the bar m3, has for its object to remove at pleasure the one or the other of the two catches; the upper, when the upper end of the rod pushes against it; the under, by means of the above mentioned pin s3. Both the catches are never raised at once, but either the under or the upper holds the rack bar fast, by pressing against one of the teeth. The vertical motion up or down, which the rod l3 must take to effect the lifting of the catches, is given to it from the copping beam p; since upon it a horizontal arm v2, [fig. 341.], is fixed, that lays hold of that rod. Upon the pushing rod are two rings, h3 and k3, each made fast by a screw. When the copping beam is in the act of going up, the arm v3 at the end of this movement, pushes against the ring h3, raises up the rod l3, and thus removes the catch w3, [fig. 337.], from the teeth of the rod q3, before which it lies flat. At the descent of the copping rail, v2 meets the ring k3, when the motion in this direction is nearly completed, draws down the rod l3 a little, by means of the same, and thereby effects the removal of the catch x3, [fig. 337.], from the rod q3. Every time that one of the catches is lifted, the rack recovers its freedom to advance a little bit in the direction of the arrow; so far, namely, till the other catch lays hold upon the tooth that next meets it. The reason is thus manifest why the teeth of the upper and under sides of the bar q3 are not right opposite to each other, but in an alternate position.
From the rack-bar, the sliding of the cone k′, and the raising of the shaft y2, each by minute steps at a time, is produced as follows:—
A large rectangular lever t1, v1, whose centre of motion is at p4, has at the upper end of its long arm t1, a long slot through which a stud r3 upon the rack q3 goes ([fig. 340.], [341.], [337.],) so that the lever must follow the motions of the rack bar. The end of the short arm of the lever bears, as already mentioned, the step of the shaft y2; hence the friction disc x1 will be raised in proportion as the rack bar advances, and will come nearer to the middle point of g1; consequently, its revolution and the shifting of the bobbins will become slower. Upon the cylindrical rod n3, the piece s1 s1 furnished with a long slot is made fast, by means of a tube z3, ([fig. 337.]) and a screw. A fork u u, which by means of the screw nut a4 is made fast in the slot, embraces the arm t1 of the bent lever; and a tube r1 rivetted to the surface of s1, is destined to take up the draw rod q1 of the cone k1, [fig. 337.] A weight f4, whose cord b4 is made fast to the cylindrical rod n3, endeavours to draw this rod continually in the direction of the arrow. In consequence of this arrangement, every time that the pushing bar l3 lifts up one of the catches, the cone k1, the lever t1 v1, and by it the rack bar q3, are set in motion. It is obvious, that the motion of the cone may be made greater or less, according as the fork u u is fixed further up or down in the slot of s1.
The number of the teeth upon the bar q3 is so ordered, that the bobbins are quite full when the last tooth has reached the catch and is released by it. The rack bar, being restrained by nothing, immediately slides onwards, in consequence of the traction of the weight f4 and brings the machine to repose by this very movement, for which purpose the following construction is employed. A rectangular lever which has its centre of motion in g4 is attached to the side face of the beam A, and has at the end of its horizontal arm a pulley d4, over which the cord b4 of the counterweight f4 is passed. The end of the perpendicular arm is forked and embraces the long and thin rod k4, to whose opposite end the fork l4 is made fast. Through this fork the band which puts the machine in motion passes down to the pulley a1. With the bent lever another rod c4 is connected at h4, which lies upon the puppet e3 with a slot at e4, and hereby keeps the lever g4 in its upright position notwithstanding the weight f4. In the moment when, as above stated, the rack bar q3 becomes free, the arm p3 of its fork pushes in its rapid advance against the under oblique side of e4, raises this rod, and thereby sets the lever g4 free, whose upright arm bends down by the traction of the weight, drives the rod k4 before it into the ring i4 fastened to it, and thus by means of the fork l4 shifts the band upon the loose pulley b1. But the machine may be brought to repose or put out of geer at any time merely by shifting the rod k4 with the hand.
The operation of the bobbin and fly frame may be fully understood from the preceding description. A few observations remain to be made upon the cone k1, the rack-bar q3, and the speed of the work.
When we know the diameter of the empty bobbins, and how many turns they should make in a given time in order to wind-on the sliver delivered by the fluted rollers and the spindles; when we consider the diameters of the spindle pullies q, and t2, as also the drum. m1, [fig. 332.], we may easily find the diameter which the cone must have for producing that number of turns. This is the diameter for the greatest periphery of the base. The diameter of the smaller is obtained in the same way, when the diameter of the bobbins before the last winding-on, as well as the number of turns necessary in a given time, are known.
A bobbin and fly frame of the construction just described delivers from each spindle in a day of twelve hours, from 6 to 8 lbs of roving of the fineness of 11⁄2 English counts. One person can superintend two frames, piece the broken slivers, and replace the full bobbins by empty ones. The loss of cotton wool in this machine consists in the portions carried off from the torn slivers, and must be returned to the lapping machine.
The fine bobbin and fly frame does not differ essentially from the preceding machine. The rovings from the coarse bobbin and fly frame are placed in their bobbins in a frame called the creel, behind and above the roller beam, two bobbins being allowed for one fluted portion of the rollers. These rovings are united into one, so as to increase the uniformity of the slivers.
The invention of the beautiful machine above described is due to Messrs. Cocker and Higgins of Manchester, and as lately improved by Henry Houldsworth, junr. Esq., it may be considered the most ingeniously combined apparatus in the whole range of productive industry.
In the fine roving frame the sliver is twisted in the contrary direction to that of the coarse roving frame. For this reason the position of the cone is reversed, so as to present in succession to the band or strap, diameters continually greater, in order that the rotation of the bobbins may be accelerated in proportion as their size is increased, because here the flyer and the bobbin turn in the same direction, and the winding-on is effected by the precession of the bobbin; but if the winding-on took place by its falling behind, as in the coarse bobbin and fly frame, that is, if the flyer turned less quickly than the bobbin, the rotatory speed of the bobbin would be uniformly retarded; in which case the cone would be disposed as in the coarse frame.