The most popular, and reputedly the beet, of these is the one introduced by Lords, and called the "lever-" or " piano-feed '' motion, from its being in principle similar to, and in figure distantly like, the arrangement of the keys of a pianoforte. Fig. 530 will help to explain its details. Fig. A shows it in section : a represents the be,ater, the dotted line tracing the circle which its blades describe in their revolution. Instead of a pair of feed-rollers, as usual for delivering the cotton to the beater a, the bottom one is replaced by a series of levers c, extending across the frame, arranged as in Fig. C. In B, is shown a different form of the short end c of the lever, adapted for long-stapled cotton. By means of a hook at the extremity of the lever-arm e, the levers arc attached to rods f, which increase in thickness at the end where they pass between two horizontal plates or bars g, laid parallel on the back and front of their pendant extremities. In the interstices, small bowls are introduced, shown by the dotted circles The rod f, on the right, is slotted for the reception of a connecting-rod attached to the levers, the second of which is connected with the strap-lever p, seen between the cone-drums in Fig. 531. A sector wheel, on the strap-lever p, gears into a similar one on the strap-lever ; q, r arc cone-drums, and s is the strap by whioh motion is transmitted from one to the other.
The action of the different parts is as follows :—When the cotton is matted, or unevenly spread upon the lattice, causing a thick portion to go beneath the roller b, the short end of the lever c is pressed down, the long arm e is raised ; this pulls up the rod f, the thick end of which, coming up between the bowls i, presses the rods in the only direction in which they can move—towards the slotted rod at the end, which, through the connecting-rod and levers above described, moves the strap s upon the cone-drums q and r, and regulates the speed according to requirement ; the cone drum r gives motion to the feed-roller b, through the worm on its shaft. This has proved to be a very efficient arrangement, and has been extensively adopted. It can be attached both to the first and second scutcher.
Lord's finisher lap machine, with the " piano" feed attachment, is illustrated in Fig. 531. The creel holds from four to six laps n, whioh, by meane of the lattice x, revolving on the rollers at each extreniity of the creel, deliver a three, four, or sixfold sheet of cotton to the feed-roller b ; this, by means of the evener, or piano feed, just described, is made t,o deliver its burden to the beater a, at a uniform rate. The bottom of the beater case A contains a grid d, whilst a longitudinal grid di extends to the dust-cages v. At C, the casing is usually glazed, or a doorway is formed, in order to permit inspection of the interior. Glazing is preferable, as a doorway interferes with the a,ction of the exhaust draught. Next to the dust-cages, are the compression-rollers to, through which the cotton
passes to the fluted rollers z, at the end of the frame, which, slowly revolving, wind it upon a roller, called the " lap-roller." When the lap y is completed, it is lifted from the frame, and laid aside, and the roller is withdrawn, and replaced to wind on another lap. The soft mass of cotton quickly closes up the space left by the withdrawal of the roller ; and ordinarily, when the lap has to be skewered, for placing in the carding-engine, considerable difficulty and waste are the result. In order to obviate these drawbacks, a plan has been devised and patented by H. H. Clayton, manager of Kingston Mills, Hyde, which is thoroughly successful. In place of the solid lap-roller, the inventor substitutes a tube-roller, into which he inserts a long pin, having a fiat head, of greater diameter than the roller. When the latter is withdrawn, the pin is left in the cavity, retained by the head, thus preserving the bore, maintaining the form, and facilitating the handling, of the lap, whilst time and labonr are economized, and all waste from the " stabbing " of the lap is prevented.
The process through which the cotton passes is very similar to that in the compound opener previously described. Tho draught of the feed upon the laps in the creel is very slow, and stands in remarkable contrast to the action of the swiftly revolving beater. The exhaust-fans also revolve very rapidly, whilst the dust-cages move at a slow pace, in order to allow the draught to deposit a thick sheet of fihre upon the exposed portion of their surfaces.
The finisher lap machine is used for the purpose of completing the cleansing procets, and obtaining a uniformly level lap, by doubling the laps from the scutcher. The idea which snggested the latter plan is to some extent erroneous. The assumed result would be achieved if it depended solely upon mechanical influences ; hut to these is closely allied a pneumatic force, which greatly modifies the process. The cotton, after passing the beater, is drawn by the current from the fans to the dust-cages ; upon the exterior of these, it is accumulated, until the layer becomes impervious to the air, when the cotton ceases to be drawn to that spot, and is diverted to other portions of the cages, where the draught is still exerting its influence. Au even delivery of the cotton may aid, but will not necessarily secure, the formation of an even lap, as the latter will quite as much depend upon the uniform strength of the current over the exposed surfaces of the cages. Should this vary appre ciably in any portion, the lap will be thinner there than elsewhere. The pneumatic principle is dispensed with in all machines subsequent to the finisher lap machine.