to be subjected to the action of a beater (A) whose teeth first seize
tufts of cotton and then fling them upon a grid (B), to be subsequently
seized by other teeth and again flung off until dirt and other
impurities pass between the grating. The beater may be cylindrical
(as at A) or in the form of a truncated cone: in either event, from
four to twelve rows of teeth project from its surface. It is from
18 in. to upwards of 36 in. in diameter, approximately 40 in. wide,
and the largest cylindrical beaters make from 300 to 700 revolutions;
whilst conical beaters make about 1000, and small ones make from
1000 to 1500 revolutions per minute. The opened cotton is carried,
in the direction indicated by the arrows, upon a strong blast of air
which is generated by a fan (H), and this deposits it in patches
upon the surfaces of two perforated zinc or wire cylinders (C), but
dust and foreign particles pass through the interstices. As these
cylinders revolve towards each other the cotton passes between
them in the form of a sheet to a pair of feed-rollers (D), which may
again deliver it to a beater with two or three blades; if so, from this
beater the cotton is next borne on an air current to, and between,
a second pair of perforated cylinders. In either event, the final
cages (C, C) deliver the cotton to feed-rollers (D) and they pass it to
calender-rollers (F), by which it is compressed into a sheet, and
finally coiled into a lap (G). Various kinds of openers have been
patented, all of which differ in some important respects; for example,
a hopper feed may be substituted for the trunk or the lattice feed,
in which event the cotton from the mixing room is conveyed mechanically
upon lattices, and deposited in a hopper affixed to an opener.
In this hopper a sloping spiked lattice elevates the cotton to an
evening roller, whose office is to sweep back the surplus supply from
the spikes, but allow the requisite quantity to pass forward to the
beater. A regular supply of cotton to an opener is of great importance,
and in order to insure it a table is often formed by substituting for
the lower roller (E) a series of levers (A, fig. 4) all mounted upon a
fulcrum (B), and having their free arms weighted by wedge-shaped
pendents (C), that are separated by bowls (D). A fluted feed-roller
(E) is fixed above this table and the cotton is led over the lever
but beneath the roller. If the cotton is unequally distributed, thick
places will press down the levers and thin ones will permit them to
rise (as at A′, E′). The rise of one pendent may be cancelled by the
fall of another, but any balance of their movements is transmitted
to a belt fork which governs a belt running upon a pair of inverted
cones, and by this means the belt is traversed to and fro to drive the
feed-roller (E) at a superior speed when the supply of cotton is
insufficient, and at an inferior speed when the supply is excessive.
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| Fig. 5. |
The Scutcher.—In many respects a scutcher resembles an opener; its function is to continue the cleaning and form laps of uniform weight and density for the carding engine. Occasionally the scutcher is the first cleaning machine, in which event cotton, in a loose fleece, is spread evenly upon a lattice. But in order to carry the combination of fibres one stage further, three or four opener laps are generally placed upon the feeder, so that, as the laps unroll, three or four sheets of cotton will be superposed, and in this form are passed by the lattice (F, fig. 4) and the feed-roller (E) to either one or two beaters, which are furnished with two or three blades. The beater (G) flings the cotton against the bars of a grid (H) to loosen, and cause the dirt to pass between the bars, after which the cotton is carried forward upon an air current, in the same manner as in an opener, and formed into a lap. In case two scutchers are required, the laps from the first are fed into the second, where they are similarly treated; in both machines the lever and pendent mechanism furnishes the means by which uniformity is attained. A beater may consist of a straight, smooth blade (as at G), or of a blade provided with stout teeth; in the latter event the operation resembles combing rather than beating. Two-bladed beaters revolve from 1200 to 1500 times per minute; those with three blades from 900 to 1000 times per minute.
Carding Engine.—The functions of a card (see Carding) are: to place the fibres parallel; to remove remaining impurities and immature fibres; and to form mature fibres into a porous band, called a sliver. A carding engine consists of three cylinders which are covered with cards; the first, or taker-in (see fig. 5), is the smallest; the second and largest is the main cylinder; and the third is the doffer. If the main cylinder is surmounted with a series of small ones (as at A), the engine is called a roller and clearer card. If a series of fixed strips of card are placed above the main cylinder, the engine is known as a stationary flat card. But if the strips move forward (as at B), it is a revolving flat card. In a roller and clearer card the small cylinders (E) are also covered with cards, but their teeth are bent to oppose those on the main cylinder, and they revolve with a different velocity. The taker-in is covered with saw teeth cut in a strip of steel which is fixed in the surface of that cylinder; it receives the cotton (I) from a feed-roller (C) that turns above a smooth iron table (D) called the feed plate, and strikes out the heaviest particles of remaining dirt. In passing through the fringe of lap, the teeth comb the attached fibres but deliver the loose ones to the main cylinder. The latter carries them into contact with the teeth on the rollers (E), by whose lower surface velocity combing is again effected. Short fibres become fixed amongst the teeth of (A) and (E), but those lying crosswise are transferred from (A) to (E) and from (E) to the clearer, which again presents them to the cylinder.
When long fibres are turned to point in the direction of rotation they advance upon the cylinder A to the doffer teeth, where the
