Next to the mule, there is no doubt that the most beautiful machine used in the cotton trade is Heilmann's comber. Although the details of this machine are hard to master, when once its action is understood it will be found to be really simple. The object of combing is to remove the short staples and the dirt left in after the carding of the cotton, such as is used in the spinning of fine and even coarse numbers. The operation is an extremely delicate one, and its successful realization is a good illustration of what is possible with machinery. Combing machines are usually made with six heads, and sometimes with eight. As the working of each head is identical, we only speak of one of them. By means of a pair of fluted feeding rollers a narrow lap, about 7½ in. wide, is passed into the head, in which the following action takes place: Assuming that the stroke is finished, the lap is seized near its end by a pair of nippers, so as to leave about half the length of the staple projecting. These projecting fibers are combed by a revolving cylinder, partially covered with comb teeth. When the front or projecting ends of the fibers are thus combed, a straight comb in front of the nippers drops into them, the nippers open, and the fibers are drawn through the straight comb.

This combs the tail ends, and at the same time the fibers, now completely combed, are placed on or pieced to the fibers that had been combed in the previous stroke, producing in this way a continuous fleece of combed cotton. In short, in this most striking operation, the fiber during the combing is completely detached from the ribbon lap, carried over, and pieced to the tail end of the combed fleece, for a moment having no connection with either. Since the expiry of the patent, Messrs. Bobson and Barlow, of Bolton, have constructed a great many of these machines, and have found that, as compared with the original make, it was possible to greatly increase their efficiency. They accordingly devoted much attention to this object, and have patents for several improvements. To describe these so as to be understood by everybody would be a most difficult task, and would take more space than we can afford. We simply wish to record what these improvements are, and will suppose we are writing for those who have a good acquaintance with Heilmann's comber.

DOBSON AND BARLOW'S IMPROVEMENTS IN HEILMANN'S COMBERS.

DOBSON AND BARLOW'S IMPROVEMENTS IN HEILMANN'S COMBERS.

We give herewith a perspective view of the improved machine. On examination it will be noticed that an alteration is made in the motion seen at the end of the machine for working the detached rollers. This alteration we believe to be a decided improvement over Heilmann's original arrangement. It dispenses with the large detaching cam, the cradle, the notch-wheel, the catch and its spring, the large spur wheel which drives the calender roller, and the internal wheels for the detaching roller-shaft, substituting in their stead a much simpler motion, consisting of a smaller cam, a quadrant, and a clutch. The arrangement, having fewer parts, is also much more compact than the old one, for with the driving pulleys in the best position it enables the machine outside the framing to be shortened 10 in., an important point in a room full of combers. The action of this detaching motion is positive, and enables the machine to be run at a high speed without danger of missing, as happens when the point of the catch for the old notch-wheel becomes broken or worn away. Another important feature of the new arrangement is that it allows the motion of the detaching-roller to be varied.

By an adjustment, easily made in a few seconds, the delivery may be altered to suit different classes of cotton or kinds of work without the necessity of changing the cams or the notch-wheels.

An improvement has been made in the construction of the nippers. In the ordinary Heilmann's comber, the upper blade has a groove in its nipping edge, and the cushion plate is covered with cloth and leather, the fibers being held by the grip between the leather of the cushion plate and the edges of the groove in the upper blade, or knife, as it is called. The objections to this mode of construction were that the leather on the cushion plate required frequent renewing, and unless the adjustment was more accurate than could always be relied on, the grip of the nippers was not perfect, for while at one end the nipper might be closed, at the other end it might be open wide enough to allow the cotton to be pulled through by the combing cylinder, and made into waste. In Messrs. Dobson and Barlow's nipper there is neither cloth nor leather on the cushion plate. Its edge is made into a blunt ^, upon which the narrow flat surface of a strip of India rubber or leather fixed in the knife falls to give the nip. By this plan the cushion is applied to the knife instead of to the plate, which of course makes the cushion plate, after it has once been set, a fixture; it also dispenses with the accurate setting, as is now necessary in the old arrangement.

It further does away with the frequent and expensive covering of the cushion-plate with roller leather and cloth, thus effecting a considerable saving, not only in cost of material, but also in labor, inasmuch as the nipper knives can be taken off, recovered, and replaced in one-sixth the time required to cover the cushion plates and replace them on the old system. American cotton of 7/8" staple to silk of 2½" staple can also be combed by this improved arrangement, an achievement which has been attempted by many, but hitherto without arriving at any success. Messrs. Dobson and Barlow have however overcome the difficulty by their improvements, which combine three important qualities, viz., simplicity, perfection, and cheapness. Many hundreds of other makers' machines have been altered to their new arrangements. The cam for working the nipper has also been altered to give a smoother motion than usual; one that moves the nipper quietly and without jerks when the machine runs from 80 to 95 strokes per minute. A very decided improvement has been made in the construction of the combing cylinder.

The combs are always fixed on a piece called the "half-lap," which, in its turn, is secured to a barrel called the "comb-stock." Now it is very desirable and important that these half-laps should be perfectly true and exactly interchangeable. When one half-lap is taken off for repairs, another half-lap must be ready to take its place on the cylinder. The original mode in which the cylinders were made rendered it a matter of mechanical difficulty - almost an impossibility in the machine shop - to produce them exactly alike. To avoid this difficulty, Messrs. Dobson and Barlow have reconstructed the combing cylinder, and the parts being fitted together by simple turning or boring, accuracy and interchangeability can always be depended upon. The screws which fasten the cylinder to the shaft are also cased up with the cylinder tins, thus avoiding any accumulation of fly on the screw heads.

The motion for working the top detaching, the leather, or the piecing roller, as it is variously called, has also been improved. The ends of this roller are always carried on the top of two levers that are oscillated by a connecting rod attached to their bottom ends. In the new motion the connecting rod is dispensed with, and one joint saved. The joint that remains is at the foot of the levers that carry the leather roller. This joint is constructed so that it may be easily altered, and by its means one of the most delicate settings of the combing machine, viz., that of the leather roller, may be made with greater readiness than with the old system. Further, from the mode of mounting these rollers another advantage is gained in the facility of setting them. In setting with the old arrangement, only one end of the roller is adjusted at a time; in the new, the adjustment sets the ends of two rollers. With regard to the leather roller also, it was found that as the round brass tubes in which its ends revolved had very little wearing surface, they got worn into flats on the outside, and thus worked inaccurately. In the machine under notice this defect is remedied.

The tubes are made square on the outside, and having ample bearing surface they keep their adjustment perfectly.

On the top of the detaching roller is a large steel fluted roller carried at each end by a small arm called a "horse tail." In the original machine this roller simply kept its place upon the detaching roller by its weight, and when the machine came to be run at high speeds it was found that owing to its lightness the contact thus obtained was not reliable, the flutes or ribs of the roller slipping upon those of the detaching roller, which for good work is undesirable. This is remedied by placing a heavier top roller in the horse tails, which is made with a broader bearing so as to give greater solidity to the top roller. Another good idea we noticed in this machine was in the application of a treble brush carrier wheel, which permits of the brushes being driven at three different speeds as they become worn. For instance, when the brushes are new the bristles are long, and consequently they are not required to revolve as quickly as when the bristles are far worn. By this improvement the brush lasts considerably longer than in any other system of machine.

Their speed can also be regulated according to the length of the bristles, and the change from one speed to the other can be effected in a very few minutes.

A common defect in combing machines is the flocking that frequently happens. This is the filling up of the combs on the cylinder with dirt and cotton, which the brush fails to remove. Although in general appearance the cleaning apparatus is the same as the ordinary one, modifications are introduced which make its action always effective and reliable. We were informed by a mill manager, who has a great number of these combers, that he meets with no inconvenience from flocking from one week end to another. Altogether, it will be seen that Messrs. Dobson and Barlow have almost reconstructed the machine, strengthening and improving those parts which experience showed it was necessary to modify. As a result their improved machine works at a high speed (80 to 95 strokes per minute, according to the class of cotton), with great smoothness and without noise, and from the almost complete absense of vibration the risk of breakages is reduced to a minimum. - Textile Manufacturer.