80 TECHNOLOGY. 
top card, on the surface of which they remain until entirely carded out by 
the revolutions of the drum. On this account the first top cards require 
cleaning oftener than the others. The fibres of cotton are now, after being 
subjected to the operation of the top cards, taken off by the small cylinder, 
L, called the doffer, which is clothed with spiral strips of card cloth, and 
revolves in contact with the main cylinder. By its slow motion, in a direc- 
tion contrary to that of the main cylinder, the doffer strips the cotton from 
the main cylinder drum, and clothes itself with an exceedingly thin fleece, 
which is taken off upon thé opposite side of the doffer by the dofing knife, 
m. This apparatus consists of a steel plate, the lower edge of which is 
finely toothed, and which has a rapid up and down motion imparted to it 
tangentially in contact with the surface of the cylinder. ‘The cotton is thus 
combed off in a thin bat of the width of the doffer cylinder, but it is immedi- 
ately condensed into a small riband or card end by passing through a 
funnel, ¢ (jig. 12). This card end, called also a slwer, is drawn forwards by 
the rollers seen at n. This apparatus consist of three pairs of cast-iron rol- 
lers, k, 7, m. The underneath rollers, & and J, are finely fluted, and the 
upper ones are covered first with flannel, then with leather, to give them a 
smooth elastic surface. 
The upper rollers are pressed firmly against the lower ones by uprights. 
As the rollers 7 revolve with greater velocity than the rollers %, the card end 
is drawn and extended between them. After the fleece has been converted 
by the action of the rollers into a flat riband, it again receives an elliptical 
form by passing through a vertical slot in a metallic plate, through which it 
is drawn by the rollers, m, which are pressed together with but little force. 
The card end now has a very open, spongy texture, and scarcely sufficient 
tenacity to hold itself together. From the last pair of rollers it falls into tin 
cans, 0. In many manufactories the card ends from several machines are 
~ wound immediately upon a lap roller or large bobbin, ready to be taken 
immediately to the drawing-frames. In other factories the card ends as 
they run from a number of machines are united together and conducted 
through wooden troughs, and at last are wound upon a large bobbin into 
a fleece of parallel ribands ready to be taken to the drawing-frame. 
Motion is communicated to the different parts of the machine in the 
following manner. Upon the axle of the main drum, without the frame of 
the machine, are the ordinary fast and loose pulleys, and a smaller pulley 
( fig. 14), giving motion by a crossed band to the stripper, F; also a pulley, 
R, seen in dotted lines in jig. 12, communicates motion through a crossed 
band to the licker-in, p. There is also another pulley, s (jigs. 12 and 13), upon 
the axle of the main cylinder which drives the pulley, 7, on the axle of 
which are two cranks (fig. 13) which communicate a rapid up and down 
motion through the rods, p, to the toothed knife,m. The rods, p, are guided 
by the horizontal arms, 0, which are so adjusted that the knife vibrates in 
contact with the surface of the doffer cylinder, t. Upon the opposite end 
of the main cylinder shaft is a pinion, m, which engages with a wheel, 2, 
on whose axle is another pinion, 3, which meshes with a wheel, 4, producing 
a slow motion which the latter wheel transfers to the doffer cylinder, 1, 
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