US2398957A - Device for guiding shuttles on circular weaving looms - Google Patents

Description

H. PELCE 2,398,957

DEYICE'FOR GUIDING SHUTTLES ON CIRCULAR WEAVING LOQMS April 23, 1946.

F iled Feb. 14, 1945 Patented Apr. 23, 1946 Henri Pelc, Paris, France, assignor to Saint Freres (Societ Anonyme), Paris, France Application February 14, 1945, Serial No. 577,91? In France February 11,1942

2 Claims. (01. 139-13) The present invention has for object a device for guiding shuttles on circular weaving looms, in particular those in which the change-over of the warp threads takes place relatively to a mean beating plane substantially at right angles to the vertical axis of the loom and in which each shuttle is propelled by means of a pushing roller having a circular movement of translation concentric with the axis'of the loom and effecting, moreover, a movement of rotation about its axis.

The invention has more particularly for object certain improvements in the sliding track of the shuttles. I In fact, in looms of the type considered, it has been deemed necessary up to now to ensure an accurate and positive transverse guiding of the shuttles, in such a manner as to hinder the least possible the beating and crossing movements of the warp threads. For that purpose, the shuttles are guided by means of annular members constituting a sliding track having a cross section in the shape of a T, a dove-tail, or the like, in which the shoe, guiding'rail or the like, of the shuttle is transversely held so that it cannot escape therefrom. In the bottom of this sliding track, on which bears the sole of the shoe, are moreover provided notches or slots substantially parallel to the axis of the loom and intended to give passage to the warp threads. In some looms, the sliding track is formed. by a ring of platens radially set relatively to the axis of the loom and the inner edge of which is cut out according to the profile of the shuttle shoe. In other looms, said sliding track is formed. by a circular ring of cylindrical pins concentric with the axis of the loom and against which bears the sole of the shoe, Whereas the inner face of said shoe is guided by two opposed rows of pins arranged in overhanging position on either side of the mean beating plane of the sheds.

If these known devices ensure, in general, satisfactory guiding of the shuttles, they constitute, on the contrary, a more or less serious danger for the warp threads. In fact, in looms of the type considered, it is practically impossible to prevent the warp threads from becoming spaced away from the substantially radial plane in which their beating movement must take place. This arises from the fact that the warp thread, which cannot be guided throughout it length, may be subjected to the action of slight difierences of tension, to vibrations, irregularities, friction stresses on the thread on the shuttle shoe, inertia and, finally to the action of a slight angular displacement of the fabric in the direction in which the shuttles ad- Vance, etc.

Now, in known looms,tne-warpthread laterally displaced may remam hooked-on me teeth and determine rapid wear; Consequently; the

shoes must be frequently replaced for avoiding play in the guiding oreven moreseriousmech-anicalaccidents.

The object of the present-invention is'to remedy all these inconveniences whilst ensuring sufflcient guiding of the shuttles. It essentially c'onsists'in the fact that, on: the one hand, the guiding. of the shuttle slice is ensud ed by a sliding track having a U-shaped' transverse profile, open towards the centre of the loom and the bottom of which, aperturedifor the passage of the warp threads, receives-the sole of the shoawhe'reas the upper-and lowei' edges'i oi said shoe are laterally guided with some-play by continuouscircular rails, forming the-branches of the U, and that, on the other hand,- the body of the shuttle is guided between the two layers of warp threads which, by the oblique pressure exerted on said-shuttle body, .holdtheushoe-pres'sed against the sliding I track;

Accord-ing ito another .te'atu re ofth'e' invention, the bottom of the sliding" ack can be formed by a circular ring of. pins, platens or thelike, concentric with the oi tneloom and having a diameter slightly greater than-that ot the anti- .friction linings. The shuttleshoe is pressed against saidipins oriplatens by' th'e combined effect of the pressure of the-warp threads and of (Sentriiugal' .force during the operation of the loom.

The accompa' nying drawing snows, byway of example sim ly an indication and not in a limiting sense, an embodiment-oi the present inven tion.

Fig. '1 is a horizontal section withparts in elevation. a

Fig.- 2. is avertical section made according to line .rmnnrrg; 1.

' Fig. 3-.is a..iperspective-view [designates thebody' ofa shuttle, provided with a shce z, then sole otwhich is lined with sliding skids 3, for instance of hard wood. The latter are intended to slide on a cylindrical track, formed by a ring of platens 4, concentric with the axis of the loom. The ends of said platens are embedded respectively in two upper and lower annular supports 5 and 6, the inner faces of which are lined with an anti-friction coating 1. and 8, for instance of hard wood. 7 The unit'formed by the platens 4 and supports 5, 6 constitutes a sliding track having a U-shaped cross section open in the direction of the axis of the loom, and in which is guided the shuttle shoe 2. The space separating the sliding surfaces of the anti-friction linings I and 8 is chosen greater than the width of the shoe so that the latter can freely move with a certain amount of transverse play.

The warp threads 9 and ill, the change-over movements of which are controlled by heddles H and 2, slide on the edges of the shoe 2 during the passage of the shuttle l and press against the upper edge of the well l3, on which the fabric is formed. The diameter of the body I of the shuttle is so chosen that the warp threads are compelled to bear and to exert a pressure on said body at a point located between the shoe and the bottom of the shed; the inner edges I6 of the faces of the shoe 2 are rounded to prevent them from wearing and even cutting the threads 9 and Ill.

The warp threads 9 and It! being suitably stretched, this arrangement has for result:

On the one hand, that the edges of the shoe are held spaced away from the sliding surfaces of the anti-friction linings I and 8,

On the other hand, that owing to the resultant of the oblique pressures exerted by the threads 9 and I0 on the body I of the shuttle between the sliding track and the bottom of the shed, the skids 3 are firmly pressed against the platens 4, even when the loom is stopped.

The clearance provided between the edges of the shoe 2 and the lateral guiding linings 1 and 8 offers, on the other hand, the advantage of allowing the warp threads to be placed in position;

said clearance finallyavoids the rolling of said threads which might affect their resistance and consequently, the quality of .the fabric.

The platens 4, forming the cylindrical sliding track, are moreover calculated to withstand the pressure of the shuttles under the action of centrifugal force. It is easy to notice that the guiding of the shuttles will be so much the more accurate as their speed of circular translation is greater. n

In the example illustrated, the propelling of the shuttle l is effected by a pushing roller l4, mounted on a plate rotating about the axis of the loom and, consequently, having a circular movement of translation about said axis. Said roller [4 pushes before it a roller [5, freely mounted on the real: part of the shuttle. Superficial examination of this arrangement may lead to suppose that the reaction of said asymmetrical thrust must cause the rocking of the shuttle. Now, experience has shown that the shuttle is always held in its sliding track, whatever may be the speed with which it is propelled, and that the device according to the invention ensures with a minimum of stress, ease of sliding which cannot be attained with any of the known devices of this kind.

One of the particularities common to all the shuttles of circular weaving looms, is the shape in an arc of circle of the shoe, the edges of which, parallel on a certain length, are guided withplay between two parallel sliding surfaces. This arrangement has for result that, notwithstanding the lateral play of the shuttle, the shoe cannot rock between its lateral guides.

Moreover, it is obvious that this particularity alone could not prevent the shuttle from being subjected to pitching movements of small amplitude, precisely due to the lateral clearance and which would be prejudicial to the satisfactory operation of the loom; But, other factors intervene for stabilizing the shuttle and ensuring a movement thereof exempt from any vibration. Centrifugal force, for instance, maintains the sole of the shoe pressed against the platens of the sliding track, and so much the more firmly as the speed with which the shuttle is propelled is greater. Furthermore, and in particular on looms in which the shed, slightly opened by the heddles, is V widened by the shuttle shoes, the resultant of the oblique pressures of the warp threads on the body of the shuttle contributes in pressing the shoe against the sliding track and in preventin any pitching.

Experience has shown that, even when the shuttles are uncovered, that is to say, when all the warp threads are for instance lowered below themean beating plane of the sheds, the shuttles can continue to advance by assuming a slight inclination, without leaving their guiding track and without damaging the warp threads. Moreover, even in this case, the resultant of the stresses acting on the shuttles is so set that it is impossible for the latter to leave the sliding track.

Finally, a particularity of the invention consists in perfecting the stability of the shuttles by arranging the pushing roller I4 and the pushed roller I5 in such a manner that the direction of the thrust passes between the device guiding the shuttle and the centre of gravity of the latter, as close as possible to the former. From the accompanying drawing, it is easy to understand that this condition is satisfied in the embodiment illustrated. 7

Whilst allowing certain weaving defects to be eliminated, this arrangement offers the advantage of being of great simplicity and of rendering possible the instantaneous removal of the shuttles, for changing the nature or the dimensions of the fabric or for any other'reason.

By avoiding the guiding without play'of the shuttle shoes, usual on certain looms, a smoother and more positive operation of the entire loom is obtained. Considering that, owing to the arrangement of the guidin track according to the invention it is impossible for the warpthreads to straddle and that they have never to pass around any projections, the cause of frequent accidents,

it is possible to increase the number of the warp threads and even to increase the speed of the looms.

Of course, without departing from the principle of the invention, it is possible to modify at will the form and arrangement of the elements of the device according to the invention. It is thus that the radial platens, the inner edges of which form the sliding track for the shuttle shoe, might be replaced by fixed or rotating cylindrical pins. Moreover, the shuttle might be propelled by means of any device other than that illustrated in the drawing.

What I claim as my invention and desire to secure by Letters Patent is:'

1. In a device for guiding shuttles on circular weaving looms, in particular on those in which the shed is slightly opened by the change-over device and, then largely opened by the shuttle shoe which moves in a U-shaped circular track open in the direction of the centre of the loom and the bottom of which is apertured for the passage of the warp threads, an arrangement of the circular track for the shuttle, of said shuttle and 5 of the layers of warp threads such that the shuttle shoe, clamped between the layers of warp threads, slides with play between the lateral sliding rails of the circular track and is held suspended between said lateral rails by the layers of warp 10 HENRI PELCE'.

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