US31969A - Let-off foe - Google Patents

Description

U HE@ @Tf `r opinion.

IVILLIAM H. GRAY, OF DOVER, NEW' HAMPSHIRE LET-OFF FOR LOOIJIS.

Specicaton of Letters Patent No. 31,969, dated April 9, 1861.

To all whom it may concern Be it known that I, IVM. H. GRAY, of Dover, in the county of Stratford and State of New Hampshire, have invented a new and Improved Let-Off for Looms, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, making part of this specification, in which- Figure l is a plan, Fig. 2 an end view, Fig. 3 details of the let off motion detached from the loom.

The delivery of the yarn from the beam is governed entirely by the tension of the warps, and is effected by the return motion of the lay independently of the mechanism which effects the take up, except that the latter is effected by the forward beat of the lay.

In the accompanying drawings A are the yarns which proceed from the beam B over the whip roll f to the weaving point; the woven cloth passing in the usual way over the breast beam to the take up roll C. The latter roll is operated positively by means of a crank C upon the lay shaft C2 which crank carries a pawl C3 by the vibrations of which the intermittent rotary motion is communicated to the ratchet wheel C5, the arbor of which carries a pinion C3 which engages with a gear C7 upon the arbor of the take up-roll or cloth beam C. This roll is roughened and the cloth after passing nearly once around is wound upon the roll C8, the axles ofV which rise in slotted guides in the customary manner as the cloth upon the roll accumulates. Any return motion of the cloth beam is prevented by the retaining pawl C. The yarn beam B carries at one extremity a gear B which engages with the worm B2 upon the upright shaft B3 to the bottom extremity of which is secured a circular disk B4 immediately above which is an arm B5 which fits snugly though not tightly upon the shaft and works freely around it. From the arm B5 is suspended a curved clamp or jaw B6 which works freely around the pin e as a center. The interior of the jaw B6 is curved to correspond nearly to the circular exterior of the disk B4, so that it may be moved freely around the disk when its ends are left free. The jaw is also so hung at e that if it be held from moving at this point while its opposite extremity is moved in the direction of the arrow (Fig. 3) the extreme end or nose a of the jaw will bind upon the circumference of the disk B4, and then upon further motion in the samedirection the disk will be carried with the jaw and a rotary motion to a certain extent will be imparted to the shaft B3, which, through the connections already explained, will turn the yarn beam and let off a certain amount of yarn; the amount `of yarn let off being dependent upon the position of the nose a at the1 moment when it is caused to grip the dis To the inner extremity of the jaw B6 is attached at c a bent rod B7 of the form seen in Fig. 3, which carries an adjustable stop BS, against which one of the swords of the lay strikes upon its return motion and after each beat. It will be seen on inspection of Fig. 3 that on the inner end of the jaw B6 being thrownback by the blow of the lay upon the stop BS if the jaw be left free at the opposite extremity a it will simply swing around carrying the arm B5 with it, but that l on the motion of this arm being checked any further motion of the jaw in the direction of its arrow will cause it to grip the disk and carry it with it. This gripping of the disk B4 by the jaw at the exact moment required to give ofi' the required amount'of yarn after each beat of the lay, is effected in the following manner.

D is a rod which I term the tension indicator and which is of the form seen most clearlyv in Fig. 3. At g it is allowed to turn freely or pivot in bearings secured to the framework, the bent portion D pressing upon the woven cloth with a force determined by the adjustable weight D2 upon the arm D3 projecting from the rod. At Di the rod is bent downward and is jointed to a rod D5 the other end of which is jointed to the arm B5.

The operation of this mechanism `is as follows: The weight D2 is adjusted upon its rod D3 so asV to produce the required tension upon the warps, the cloth is then wound upon the roll C8 until the arm D3 is horizontal, or this may be effected by turning the shaft B3 by means of the hand wheel F. On the lay making its forward beat the cloth is taken up a certain amount and the warps are thereby strained. This turns the rod D in its bearings and throws the rod D5 in the direction of its arrow, which also carries back the arm B5'in the same direction and holds it at the point determined by the llo tension of the warp. On the return motion of the lay the eye B9 upon the sword E strikes against the stop B8 and carries the jaw B6 in the direction of its arrow. The

ivot e being held stationary as before explained by the tension of the warps, the first motion of the jaw B6 causes its nose a to bind against the disk Bt whereby the disk is rotated by the further motion of the jaw. For the more perfect operation of the loom, the nose a of the jaw may be kept constantly in contact with the disk by a spring 71 one end of which is attached to the jaw while the other bears upon the arm B5. This I have not found to be necessary in most cases.

It is obvious that the above described mechanism will let ofi an amount of yarn after each beat of the lay exactly equal to the amount which was taken up by that beat, and that the tension of the warps will always be the same at the moment when the lay beats up.

In the machine represented in the drawings the arm D4 is connected permanently to the rod D5; in practice however there should be an adjustment somewhere between the rod D and the rod D5. Any positive take up may be employed in place of the one described, and it is evident that the form of the parts may be varied without departing from my invention, and the same is also true of the relative position of many of the parts, for instance, it matters not on which side of the cloth the rod D bears, whether front or back, and whether the portion D bends up or down providedthe connections between this rod and the let off be suitably varied to correspond with this change. The strain mayfeven under certain circumstances be taken from the warps back of the lay, but this will manifestly be inferior to the method of taking it from the cloth as the warps are subjected to the vibration occasioned by the beat of the lay. In practice it is lfound well to put sufcient friction upon the disk B4 or upon some other attachment to the shaft B3 to prevent any frivolous motion of the yarn beam. It is also obvious that the weight D2 may be replaced by a spring without altering the spirit of my invention.

What I claim as my invention and desire to secure by Letters Patent is- The combination of the balanced rod D, the arm B5, disk B4 and jaw Bb or their equivalents for determining the tension under which the loom shall operate and the amount of let 0E to be effected after each beat of the lay.

WVM. H. GRAY. [Ls] Witnesses M. D. WHITAKER, ALONZO WAIT.

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