COTTON MANUFACTURE.

363

occasion the rupture of the cord, because the front fluted rollers move with uniformfpeed, and therefore deliver always the same length of sliver in the same time. Itls therefore necessary to diminish the - velocity of the bobbins, or the number of theirturns, in the same proportion as their diameter increases, in order that the primaryVelocity may remain unchanged. Moreover, it is requisite for the proper distributionof the cord upon the bobbin, and the regular increase of its diameter, that two of itssuccessive convolutions should not be applied over each other, but that they should belaid close side by side. This object is attained by the up and down sliding motion of thebobbin upon the spindle, to the same extent as the length of the bobbin barrel. ThisU P and down motion must become progressively slower, since it increases the diameterjd the bobbin at each range, by a quantity equal to the diameter of the sliver. Whata3 now been stated generally, will become more intelligible by an example.

Eet it be assumed that the drawing rollers deliver, in 10 seconds, 45 inches ofroving, and that this length receives 30 twists. The spindles must, in consequence,ake 30 revolutions in 10 seconds, and the bobbins must turn with such speed, that,^ e y wind up the 45 inches in «10 seconds. The diameter of the bobbin barrels beingin V^'es, their circumference of course 4\ inches, they must make 10 revolutions more30 -Il C Same time ^an the spindles. The effective speed of the bobbins will be thusbv ' ^0=40 turns in 10 seconds. Should the bobbins increase to 3 inches diameter,> the winding-on of the sliver, they will take up 9 inches at each turn, and con-sequently 45 inches in 5 turns. Their speed should therefore be reduced to 30-|-5=35b Vuf* * a seconds. In general, the excess in number of revolutions, which therj? bins must make over the spindles, is inversely as the diameter of the bobbins.

e speed of the bobbins must remain uniform during the period of one ascent orof S ,^t upon the spindle, and must diminish at the instant of changing the directiona a ae i r up and down motion; because a fresh range of convolutions then begins withdiameter. When, for example, 30 coils of the sliver or roove are laid in onedo\v ^ °f *be bobbin barrel, the bobbin must complete its vertical movement up orn ’ within 30 seconds in the first case above mentioned, and within 60 seconds in^cond case.

f 0 l, e . Motions of the drawing rollers, the spindles, and bobbins, are produced in themanner : —A shaft c', figs. 332 and 333, extending the whole length of thepmj lae > and mounted with a fly wheel dj is set in motion by a band from the runningu Pon a ,P. otl the shaft of the mill, which actuates the pulley a', b' is the loose pulleybut on band is shifted when the machine is set at rest. Within the pulley a' }

n ’' ~ ~ the shaft c' carries a toothed wheel bz with 50 teeth,

^bic^h^ 6 outs * de the frshaft p Cleans of the intermediate wheel cz turns the wheel dz upon the prolongedbut it t * 16 backmost fluted roller (m 2 , jig. 333.) This wheel dz lias usually 54 teeth;s Pifidl changed when the roove is to receive more or less twist; for as the

k^Sth^ / ev .°* Ve with uniform velocity, they communicate the more torsion the lessdz } a .°\ sliver is delivered by .the rollers in a given time. Upon the same shaft withthe fra ltll0n e2 ^2 teeth is fixed, which works in a wheel fz of 72 teeth. WithinUs U aU a change pinion gz is made fast to' the shaft of fz. This pinion, which hasof the r °^ ^4 to teeth, regulates the drawing, and thereby the fineness or numberroller ^ works in a 48-toothed wheel hz upon the end of the backmost fluted

rolle rs s *' l °\833. The other extremity of the same roller, or, properly speaking, line of^terined^^ 168 a P* n * on * 2 » furnished with 26 teeth, which, by means of the bwiadWhen w ^ ee ^ sets i n m otion the pinion %z of 22 teeth upon the middle roller,

tion&l vef - ameter of all the drawing rollers is the same, suppose 1 inch, their propor-24 teptn ° citles will be, with the above number of teeth in the wheel work, if g 2 havee (ronf 0 ! 1 .,:,*' 18 :4 ' 5 i an(I thl

The fro'nt^o V * an( l the drawn sliver will have 4£ times its original length.

inches °‘r Ver ^ ro ^ er °f the drawing frame is of late years usually made 1J orPound 27 qJ? ^ lame ter. If 625 feet of the sliver from the drawing frame weighed one

J:, 1 ,2;’that , the ' roving will now go to this weight, and the number will be

lo bcrs make 1 ^ v. hank and 12 hundredths to the pound. The front pair of fluted' v heq of nno S * °V t ^ revolutions, and delivers 282*6 inches of roving in the minute,fi T h e S ni\ ,i mCl ^ dlameter -

in an in? S % ^32 and 333), rest, with their lower ends, in steps l , which are

n !s beam is beam or bar m. To protect it from dust and cotton filaments,

P*ssag eo « * ar pished with a wooden cover n, in which there are small holes for theatll Pose the w'^nl 0S over the steps. In jig. 332, two of the eight covers n, which

jw ea °h spiuml* 0 6 ran " e are removed to let the steps be seen. The cylindrical part

. u st be vertical/** 5868 trough a brass ringo; and all these 30 rings, whose centrescalled b ee 7 °X er . l h e s f e PS /, are made fast to the copping beam p. This beamac hed to it hnf e *, s dest * n cd not merely to keep the spindles upright by the rings5 3 at the same time, to raise and lower along the spindles the bobbins