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THE

LONDON JOURNAL,

AND

REPERTORY

ОР

Arts, Sciences, and Manufactures,

CONJOINED SERIES.

No. CCLXIII.

RECENT PATENTS.

To LOUIS GUILLAUME PERREAUX, of Paris, in the Empire of France, engineer, for improvements in machinery or apparatus for testing and ascertaining the strength of yarn, thread, wire, strings, or fabrics.-[Sealed 31st January, 1853.]

IN carrying out this invention, the yarn, thread, wire, strings, or fabric to be tested, is submitted to a regular strain or tension until it breaks, by securing one end to a moveable pin or clamp, which is capable of being drawn back gradually by some convenient contrivance, and attaching the other end of the yarn or thread to a similar pin or clamp, which is connected with an indicating apparatus.

The machine consists of a rectangular frame, the inner sides of which form guides, wherein are placed two moveable crossheads or traversers, for carrying the pins, hooks, or clamps above mentioned, or other contrivances, to which the thread, yarn, wire, string, or fabric, to be tested, is attached. One of these cross-heads is actuated by a screw-shaft, which passes through a screw-box or female screw on the under side of the cross-head, and has a winch-handle at one end, for turning the screw-shaft and drawing back the cross-head, so as to stretch the material to be tested. The other cross-head is also moveable on the guides, but is held back by a strong double elliptical spring, connected at one end to the crosshead and at the opposite end to the fixed part of the framing. From this explanation it will be evident that, upon drawing back the first or moveable cross-head, the material or fabric 2 P

VOL. XLIII.

to be tested will be submitted to very great tension, but that the elliptical springs at the back of the second cross-head will yield, to a given extent, to the strain. It will therefore only be necessary to connect these springs to an index and dial; and, by indicating on the dial the action of the springs, the strength of the fabric or material that has been tested or operated upon will at once be ascertained. On one side of the rectangular frame, and parallel with the line of draught, is a graduated scale, which marks the degree of elasticity of the material-so important for all fabrics, and especially for woollen cloth.

In order to prevent too great a shock when the material or fabric to be operated upon breaks, the back clamp is connected, by suitable gearing, to a fly-wheel, which, when the clamp returns, is set in motion, and thus deadens the shock to which the apparatus would be otherwise exposed.

In Plate X., fig. 1, is a plan view of the machine, with the index and dial-plate removed, in order that the parts beneath may be more clearly seen; fig. 2, is a longitudinal section of the same; and fig. 3, is an end elevation,—some of the parts being shewn in section. a, a, are upright standards, which support a rectangular frame b, b, in which are placed the cross-heads c, and c*. On one side of the frame b, is placed an adjustable gauge, to measure the length of the material that is under operation, and the amount to which it has been stretched. The cross-head c, is provided underneath with a female screw d, through which works the long screw e, whereby the cross-head is moved backwards and forwards on the guides at the inner side of the rectangular frame b, b, when the screwed shaft e, is turned by the winch-handle f. The cross-head c*, is also mounted in the guides of the rectangular frame b, b, and has a limited motion therein. To the back part of this cross-head is connected the double elliptical spring g, g, the opposite end of which is secured to the horse-shoe shaped end of the fixed framing: the double elliptical spring g, works in a bridle-piece h, h. A pin i, which passes through a socket made in some convenient part of the framing, bears with one end against the side of the elliptical spring g, and is held in contact therewith by the sliding-barj, which is kept against the other end of the pin i, by the force of the helical spring k. It will be seen, on referring to fig. 3, that the under side of the bar j, is furnished with rack-teeth, which gear into the teeth, made on the upper end of a sector-rack m; and into this rack m, gears a pinion n, on the shaft o. On the boss of the pinion n, is a

ratchet-wheel p, which is driven by a click or pawl attached to one of the arms of a fly-wheel q, mounted loosely on the shaft or spindle o. The index-plate or dial r, is fixed on the top of the horse-shoe part of the frame. To the back part of the cross-head c*, is attached a toothed rack s, which gears into and drives a pinion t, on the spindle of which the index-hand u, is mounted. The thread, wire, or other material to be tested, is secured in any convenient manner to the pins or clamps v, v*, of the cross-heads c, and c*, shewn in fig. 2, and in the detached view fig. 4.

In operating with this machine, the thread, cord, or wire is secured at both ends to the pins or clamps v, v*, and the winch-handle f, is turned, to draw back the cross-head c. The thread, cord, or wire w, fig. 2, will thus be submitted to considerable strain and tension, which strain will cause the advance of the cross-head c*, and give the elliptical springs g, which are attached to the back of the cross-head, a tendency to collapse or straighten. The forward motion of the crosshead will also, by means of the rack s, and pinion t, cause the index-hand u, to move round, until the thread gives way and breaks the figure on the dial-plate, at which the indexhand points at that moment, will indicate the amount of strain to which the material has been subjected. In order to ascertain the degree to which the material has been stretched, the zero mark on the rule x, at the side of the frame, should be brought to the edge of the cross-head c*, and the exact length of the material, when strained tight, but unstretched, should be first ascertained, and then a second observation should be made, in a similar manner, just before the breakage takes place; and the difference between the two observations will shew the amount to which the material has been stretched. It will be seen that the rule x, is moveable longitudinally, in order to keep it always opposite the centre of the cross-head. When the thread breaks, the elliptical spring g, is prevented, by the gearing connected with the fly-wheel, from suddenly returning to its normal condition. The strain upon the spring tends to straighten it, and allow the pin i, and rack-bar j, to move forward; but when the spring expands again it will force back the pin i, and rack-bar j, and, acting on the toothed gear, cause the fly-wheel to rotate. By this means anything like a shock is prevented from the sudden collapse of the spring.

The patentee claims the general arrangement of machinery herein shewn and described, or any modification thereof, in which the strength of materials is ascertained by means of

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