A Dictionary of Arts, Manufactures and Mines / containing a clear exposition of their principles and practice

by Andrew Ure

In this figure is exhibited a portion of the cutters in the same situation as in [fig. 1221.]; and alongside of it is a section of the same, taken through it at right angles to the former; p, is a metallic bar or rib, somewhat of a wedge form, which is fastened to the top part of the standard a, a, seen best in [fig. 1220.] To this bar a straight blade of steel g, is attached by screws, the edge of which stands forward even with the centre or axis of the cylindrical cutter i, and forms the ledger blade, or lower fixed edge of the shears. This blade remains stationary, and is in close contact with the pile or nap of the cloth, when the bed k, is raised, in the manner above described.

The cutter or upper blade of the shears, is formed by inserting two or more strips of plate steel r, r, in twisted directions, into grooves in the metallic cylinder i, i, the edges of which blades r, as the cylinder i revolves, traverse along the edge of the fixed or ledger blade g, and by their obliquity produce a cutting action like shears; the edges of the two blades taking hold of the pile or raised nap, as the cloth passes under it, shaves off the superfluous ends of the wool, and leaves the face smooth.

Rotatory motion is given to the cutting cylinder i, by means of a band leading from the wheel s, which passes round the pulley fixed on the end of the cylinder i, the wheel s being driven by a band leading from the rotatory part of a steam-engine, or any other first mover, and passed round the rigger t, fixed on the axle s. Tension is given to this band by a tightening pulley u, mounted on an adjustable sliding-piece v, which is secured to the standard by a screw; and this rigger is thrown in and out of geer by a clutch-box and lever, which sets the machine going, or stops it.

In order to give a drawing stroke to the cutter, which will cause the piece of cloth to be shorn off with better effect, the upper cutter has a slight lateral action, produced by the axle of the cutting cylinder being made sufficiently long to allow of its sliding laterally about an inch in its bearings; which sliding is effected by a cam w, fixed at one end. This cam is formed by an oblique groove, cut round the axle, (see w, [fig. 1227.]) and a tooth x, fixed to the frame or standard which works in it, as the cylinder revolves. By means of this tooth, the cylinder is made to slide laterally, a distance equal to the obliquity of the groove w, which produces the drawing stroke of the upper shear. In order that the rotation of the shearing cylinder may not be obstructed by friction, the tooth x, is made of two pieces, set a little apart, so as to afford a small degree of elasticity.

The manner of passing the cloth progressively under the cutters is as follows:—On the axle of the wheel s, and immediately behind that wheel, there is a small rigger, from which a band passes to a wheel y, mounted in an axle turning in bearings on the lower side-rail of the standard a. At the reverse extremity of this axle, there is another small rigger 1, from which a band passes to a wheel 2, fixed on the axle 3, which crosses near the middle of the machine, seen in [fig. 1226.] Upon this axle there is a sliding pulley 4, round which a cord is passed several times, whose extremities are made fast to the ends of the sliding carriage d; when, therefore, this pulley is locked to the axle, which is done by a clutch box, the previously described movements of the machine cause the pulley 4 to revolve, and by means of the rope passed round it, to draw the frame, with the cloth, slowly and progressively along under the cutters.

It remains only to point out the contrivance whereby the machinery throws itself out of geer, and stops its operations, when the edge of the cloth or list arrives at the cutters.

At the end of one of the habiting rails h, there is a stop affixed by a nut and screw 5, which, by the advance of the carriage, is brought up and made to press against a lever 6; when an arm from this lever 6, acting under the catch 7, raises the catch up, and allows the hand-lever 8, which is pressed upon by a strong spring, to throw the clutch-box 10, out of geer with the wheel 8; whereby the evolution of the machine instantly ceases. The lower part of the lever 6, being connected by a joint to the top of the lever j, the receding of the lever 6, draws back the lower catch j, and allows the sliding frame l, l, within the bed k, to descend. By now turning the lower rollers e, e, another portion of the cloth is brought up to be shorn; and when it is properly habited and strained, by the means above described, the carriage is slidden back, and, the parts being all thrown into geer, the operation goes on as before.

Mr. Hirst’s improvements in manufacturing woollen cloths, for which a patent was obtained in February, 1830, apply to that part of the process where a permanent lustre is given usually by what is called roll-boiling; that is, stewing the cloth, when tightly wound upon a roller, in a vessel of hot water or steam. As there are many disadvantages attendant upon the operation of roll-boiling, such as injuring the cloths, by overheating them, which weakens the fibre of the wool, and also changes some colours, he substituted, in place of it, a particular mode of acting upon the cloths, by occasional or intermitted immersion in hot water, and also in cold water, which operations may be performed either with or without pressure upon the cloth, as circumstances may require.