US2624367A - Loom for circular weaving - Google Patents

Description

Jan. 6, 1953 J. DUNOD 2,624,367

LOOM FOR CIRCULAR WEAVING I Filed Dec. 21, 1950 7 Sheets-Sheet l Jan. 6, 1953 J. DUNOD 2,624,367

LOOM FOR CIRCULAR WEAVING Filed Dec. 21, 1950 1' Sheets-Sheet 2 6 co m AA, 0 54am;

7 Sheets-Sheet 3 J. DUNOD LOOM FOR CIRCULAR WEAVING .zfllflllll Jan. 6, 1953 Filed Dec. 21, 1950 an m N 3 J. DUNOD LOOM FOR CIRCULAR WEAVING Jan. 6, 1953 7 Sheets-Sheet 4 Filed Dec. 21, 1950 Jan. 6, 1953 J. DUNOD LOOM FOR CIRCULAR WEAVING FiIed Dec. 21, 1950 7 Sheets-Sheet 6 m wt fi l FLT X OW @m 2 m R. a? he W x m vm m Q? 3 &- '11 ll km -m N N W Wm .N 1 n m .0 km 0M 0 m I. I N m 3 S a 2 v N N g 3 3 3 Jan. 6, 1953 J. DUNOD LOOM FOR CIRCULAR WEAVING 7 Sheets-Sheet '7 Filed Dec. 21, 1950 Patented Jan. 6, 1953 UNITED STATES PATENT OFFICE LOOM FOR CIRCULAR WEAVING Jean Dunod, Paris, France Application December 21, 1950, Serial No. 201,964

' In France May 3, 1947 6 Claims.

My invention relates to a loom for circular weavin permitting of the weaving of natural or synthetic textile threads as well as metallic threads, wherein:

(a) The warp threads are arranged along the generatrices of a vertical cylinder and are supplied by bobbins placed at one end (for example at the bottom) of the loom, there being a number of bobbins equal to that of the threads:

(b) The opening of the shed is controlled by harness.

This application constitutes a continuation-inpart of an earlier filed application, now abandoned, Serial No. 23,606, filed April 27, 1948.

My invention has for its object to provide a circular weaving loom with means, for opening the shed to permit the passage of the shuttle during the normal operation of the loom, and means for retracting all the Warp threads towards one and same side of the reed in order to uncover the shuttle, for example to permit the re-loading of said shuttle.

One practical manner of carrying my invention into practice has been illustrated diagrammatically and by way of example in the annexed drawings:

Fig. 1 shows, in the system of harness according to my invention, one heddle in the normal position, the point connected to the member producing the to-and-iro motion being most distant from the centre of the loom and the warp thread being on the outside of the shuttle.

Fig. 2 is similar, but the warp thread has been drawn towards the centre of the loom in order to uncover the shuttle.

Fig. 3 shows one heddle in the normal position, the point connected to the member producing the to-and-fro motion being nearest to the centre and the warp thread being on the inside ofthe shuttle.

Fig. 4 is a view similar to Fig. 3 but corresponds to the position of the warp thread during the reloading of the shuttle.

, Figs. 5 to 7 are sections showing in three different positions how the internal springs are secured to slides, and how some of said slides can be arrested in the inner position. I

Fig. 8 is a plan view of the mechanism for retracting the warp threads clear from the shuttle. Fig. 8a is a fragmental plan view at a larger scale.

Fig. 9 is a section on IX-IX in Fig. 8 with parts thereof shown diagrammatically.

Fig. 10 is a section on XX in Fig. 9.

. Fig. 11 is a perspective view of details of the mechanism shown in Figs. 9 and 10.

Fig. 12 is a fragmental plan showing the positionin g'of three different slides shown in Figs. 5 to 7.

According to my invention, the harness proclucing the to-and-fro motion of the warp threads in order to normally open the shed during the normal operation of the loom is controlled by cams, and each warp thread is passed through an eye of a heddle, the harness comprising a number of heddles equal to the number oi the warp threads. Each heddle is connected through springs, on the one hand (towards the inside of the loom), to the element producing the to-andfro motion and, on the other hand (towards the outside), to a point which is normally fixed but which may be displaced at will, the external spring being more powerful than the internal spring. A special arrangement of the heddles permits all the warp threads to be drawn to one and the same side of the shuttle so as to be clear of the latter, and, in particular, to permit to replace the spool carried by the shuttle.

Referring at first to Figs. 1 to 4, it will be noted that said figures are merely diagrammatic and illustrate only the principle of the invention. On said figures, 2 designates the warp thread, 3 the bobbin which supplies this thread, 5 the reed, 6 the shuttle, and 64 the weft thread. X-X is the axis of symmetry of the reed, and Y-Y is the axis of the loom driving shaft 50. Each heddle AB extends substantially in a horizontal plane, which encounters the axis YY at the point 0, as seen in dotted line. This heddle is attached at A to an internal spring 3! and at B to an external spring 32. For sake of clearness, it will be assumed that the cam it producing the to-and-fro motion of each of the heddles is secured at O on the loom driving shaft 53 and acts upon a member 31 attached at D to the inner end of the spring 3 l. In Figs. 1 to 4, I have shown only the cam 40 and the slide 3? with its roller 39. Similarly, for sake of clearness, only one stage of slides and heddles has been shown, although practically the heddles are divided between several stages. The actual structures of said devices are shown in detail in Figs. 5 to 7.

The operation of the heddle is following: during the normal operation of the loom, it is necessary to open the shed of the warp threads 2, in order to allow for the free passage of the shuttle. Consequently, the eye 69 of any one of the heddles is drawn from E to E i. e. from one side of the reed 5 to the other side of said reed, and at the same time the adjacent heddle is drawn from E to E, and conversely. When a warp thread 2 is in the position E shown in full line in Fig. 1, the next warp thread 2 coming from the bobbin 3 is in the position E shown in dotted line in the same figure, i. e. symmetrical as to the axis X-X. Assuming that the heddle AB is directly attached to the driving member 31, it would be positively reciprocated from E to E at each action of said driving member. But it would be impossible to keep all the warp threads retracted towards one and the same side of the reed, since at every moment each two warp threads would be on one side of the line X-X whereas the other warp threads would be on theother-side.

According to my invention, it is possible to stop certain of the heddles without stopping the driving member, and consequently to retract towards one side of the reed (for example towards the centre of the loom) all the warp threads which, at a given moment, are positioned on the other side of the reed, without at the .same time displacing towards the outside of the loom the warp threads that already are on the inner side of the reed. This result is achieved, according to my invention, by means of the mechanism that will be now described.

While the heddle AB is attached at A to an internal spring 3|, this latter being itself attached at D to the sliding member 31, as disclosed above, this heddle is attached to B to an external spring 32, the outer end C of this spring being attached at C to a semi-fixed point,"that is a point which may normally be considered as fixed, but which can, when necessary, be displaced at will by means of a suitable control mechanism represented diagrammatically in Figs. 1 to 4 by a cable '34 passing over an idle pulley 35.

The spring 32 is stronger than the spring 3|. Said spring 32 can not expand as long as the spring 31 is allowed to expand. But the expansion of the spring 3i is limited by a suitable tension limiting device 313. Said device 36 may be constituted by a tube forming a sheath, against the inner ends of which the ends 31a, 3 lb ofxthe spring 3! bear (Figs. 1, 3 and 4). The device 36 may also be constituted by a flexible cable the ends of which are attached to the ends of the spring 3 I. Such tension limiting devices are well known in the art. The device 36 is designed for allowing a displacement AA=EE", equal to the opening of the shed. 7

It will thus be seen that, in normal operation, owing to the said tension limiting device 36, the spring 3! behaves as a rigid connection, whilst the spring 32 absorbs the total motion of the heddles, since the point C is deemed to remain stationary.

Fig, 1 shows the position of the heddle and spring mechanism, in normal operation, for the threads 2. Fig. 3 shows in the same conditions the position of the threads 2. In this last figure, both springs 3i and 32 are as much expanded as possible; it is assumed that the point'C is fixed.

Now supposing that it is desired for any reason, and particularly at the time of re-loadin-g of the shuttle, to draw all of the warp threads towards the centre of the loom, which has the effect of causing the shuttle to emerge from its cage of threads and to become located outside of all the threads, it is necessary to bring to E thethreads 2 which would normally be at E at this time,

that is to say, to bring B to 'B and C to C for these threads (Fig. 2), without modifying the position of the member 31. This is efiected by releasing (as described thereafter) the cable 34, and results in bringing to C the point C Without modifying the tension of the spring 32.

The displacement of B (Fig. 1) to B (Fig. 2) is equal to the displacement of C to C and to that of E to E, since the tension of the spring 32 remains constant, the magnitude of the movement of the eccentric device from D to D being equal to the width EE of the reed and the tension of the spring '3l' being maximum. But

it is evident that the displacement AA of the end of the heddle is equal to the distance EE', magnitude of the opening of the shed, and to the distance 4C0, magnitude of the displacement of the point C; consequently There aretwo cases:

(1) The point of attachment D of the spring 31 is in its position furthest removed from the point-0.

When the cable 34 is relieved, the spring 3|, which is .no longer subject to the action of the spring 32, collapses, drawing A to A and consequently E to E (Fig. 2).

(2) The point-D of attachment of the-spring 3| is in its position D nearestto the-centre'-:0 (case of thethreads 2 in Fig. 3)

The spring 3| is extended as much as allowed by the device 38. Theeye 69 which was already at E does not shift (Fig. 3). The spring 32 is also'ex-tended.

When the cable 34 is relieved, the point C is brought at C (Fig. i) and the spring 32 (:01- lapses, the spring 31 remaining under the maximum tension.

It will be noted that, when the tensionon the cable 34 is relieved, the spring 32 remains collapsed; the point B remains stationary as well as the heddle AB, and the end B of the spring 3! alone follows, between the points D and D, the motion of the device controlling the to-and-fro movement, the spring 3| being alternatively-col lapsed or expanded.

If now it is desired to re-establish the normal process of opening of the shed, it-will suffice to pull the cable 34 for moving the point C to 0. Assuming that the mechanism had stopped in the position of Fig.4, the threads '2 assume again the position of Fig. 3, and assuming that the mechanism had stopped in the position of Fig. 2, thethreads 2 assume again the-position of Fig. 1.

From what has been said, it follows that the to-and-fro motion of the member 3! may be rendered inoperative on the threads as these threads have been moved towards the internal edge of the reed. "If necessary, it would also he possible to eifect this movement towards the external edge by :a similar system, symmetrically disposed with respect to theaxis the principle of operation would be the same, but the actual structure of the reciprocating device 3-1, 39, M would be modified.

The displacement of the point C.;t0 C, that is to say the return of the warp threads towards the internal edgeof the reed, "is-eitected in practice by means of the mechanism illustrated Figs. 8 to 11 which will be described thereafter.

I shall now refer to Figs. '5 to 7, order to indicate how the heddles are attached -in--practice to the driving device, and how it is furthermore possible, according to my invention, to produce different kinds of weaves.

In viewof the considerable number of the heddles, a certain number of these heddles may be connected to one pair of springs 3| and 32, and thesesprings .are themselves divided between several levels or stages, as is shown in :Figs. 5 to '7.

In practice, thesprings 31 are generally housed in'the bores of slides'3 l, 3l','3'!a, 31a (Figs. 5 to '7 and are securedat Dat the inner:ends:of these bores.

The slides mayconsist-of tubes-sliding in housings 38a arranged radially in a circular body 38 (Figs. 5 to -7and -'12) It will be seen that the slides may be arranged in the body 38 at several levels. Four stages of slides 31, 31' and 31a, 31'a are to be seen in Figs. to '1. The slides 31, 31' and their springs 3|, 3 correspond to a. first group of threads and the slides 31a, 31'a and their springs 3|a, 3|a to a second group of threads. The slides 31, 31' on the one hand and 31a, 31a on the other hand are connected together, respectively, by driving pins 52 and 52a, 52' and 52'a, respectively secured to the slides 31, 31a and 31', 31a and projecting from each of said slides.

In the practice, the slides 31 and 31' as well as the corresponding heddles and springs 3|, 3| and 32 are connected to a single cable 34; the slides 31a, 31a, although being apparently in a same vertical plane in Figs. 5 to 7 are, in fact, positioned under the slides 31, 31' but in a different angular setting, as viewed in Fig. 12. There are also only two stages of slides in a given radial plane of the loom, and a single cable 34 for each pair of slides. In Fig. 12, the cam 40 has been omitted, and only its outer edge or track has been indicated in chain line.

Each slide 31 receives its to-and-fro motion from a roller 39 which rolls upon the internal track of a cam 40. A second cam 40a offset by 180 in relation to the first is arranged under the body 38 (Figs. 5 to 7). It acts upon a roller 39a which issymmetrical in relation to the roller 39 and moves the slide 31a. The rollers 39, 39a are journalled on pivots 62, 62a secured to the slides 31, 31a and are maintained against the cams 40, 40a by the tension of the springs 3|.

It is to be noted that the circular body 38 is firmly secured to the frame of the loom (not shown) by any suitable means, the loom driving shaft 50 rotating freely in a circular bore of said body, whilst the cams 46, 40a are keyed at 10 to the loom driving shaft.

In Figs. 5 to 7 and 12 the tension limiting devices 36 are diagrammatically shown and reciprocate with the slides, to which they are secured at D. The arrangement of the springs 3| in the interior of the slides is necessary in the case of a loom of small diameter. In the case of a loom of larger diameter, the springs 3| may be external to the slides.

According to my invention, it is possible to temporarily stop any one of the several stages of slides and consequently to produce different kinds of weaves.

Thus, I have provided a mechanism which would arrest, for example, one of two stages alternatively or which would automatically arrest several stages successively in a predetermined order depending upon the nature of the weave desired.

For example, in the case of Fig. 5, the slides 31 or 31a may continue to operate, whilst the slides 31' and 31a are arrested in the inner position (that of the slide 31'a). A suitable system of bolts 55, 55 and 55a, 55a may be employed for arresting at will the slides 31, 31, 31a and 31'a.

In Figs. 5 to '7, it will be seen that each slide 31 is associated with an electromagnet 54 whose core 55 is biased by a spring 51 to protrude outwardly as a bolt for engagement with a notch 56 provided in the slide 31, when the electromagnet 54 is not energized. Similar arrangements are provided for the slides 31', 31a and 31a. The device operates as follows: during the normal operation of the loom, all the slides 31, 31 and 31a, 31'a are reciprocated. The electromagnets 54, 54a and 54', 54a, are energized, so that the cores or bolts 55, 55' and 55a, 55'a remain retracted against the springs 51, 51' and 51a, 51'a. Consequently, the slides 31, 31 on the one hand and 31a, 31'a on the other hand are connected by the engagement of the driving pins 52, 52' and 52a, 52'a, and are reciprocated under the action of the roller and cam devices 39, 40 and 39a, 400. (Fig. 5). But if it is desired to arrest for example the slides 31' and 31'a, the supply to the electromagnets 54 and 54a is interrupted by the rotating commutator 58. Under the action of the springs 51, 51a, the bolts 55',55a will come into engagement with the corresponding notches 56, 56a as soon as the slides 31, 31'a in their alternating motion are in their inner position (Fig. 6). Thus the slides 31', 31'a are held in said inner position during the further motion of the slides 31, 31a, the engagement between the driving pins 52, 52' and 52a, 52'! respectively being no more effective. In Fig. 6 there are shown the pins 52 and 52' separate from each other, the slide 31 being at this moment in its outer position while the slide 3111 is at this moment in its inner position. From Fig. 7 it can be viewed how it is also possible to stop the motion of three stages of slides: 31, 31 and 31a, by energizing only the electromagnet 54a so as to hold the bolt 55a retracted in the body 38. The electromagnet 54' does not need to be energized, because the slide 31' is reciprocated only by the engagement of the driving pins 52, 52'. The rotating commutator 58 may be designed, as shown in the drawings, so as to energize temporarily the electromagnets 54' and 54'a, so that the slides 31, 31'a may be temporarily arrested in the inner position according to the kind of weave desired. It is of course impossible to arrest only the slides 31 and 31a, since the slides 31' and 31a are reciprocated only by the slides 31 and 31a, by means of the pins 52, 52' and 52a, 52'a.

The mechanism for displacing the point C of attachment of the outer end of the external spring 32 will be now described, with reference to Figs. 8 to 11.

Each heddle-tensioning spring 32 (or each pair of springs 32 corresponding to two superposed stages 31, 31 or 31a, 31a of slides) is attached at its outer end to a cable 34 (Figs. 1 to 4 and 9) passing over two idle pulleys 35, and then over a pulley 43 and attached finallyat a fixed point 44 to the frame 42 of the loom (Fig. 9).

The pulleys 43 are mounted at the ends of slides 45 and 46 (in number equal to that of the pairs of slides 31, 31' and 31a, 31'a, for example eighteen) arranged half and half, at two different levels on each side of a diameter Z-'-Z (Figs. 8 and 9).

The slides carry rollers 41 which may bear against the internal tracks of a cam 48 keyed at 48a on the main driving shaft 50 of the loom and having two symmetrical crests.

It is to be noted that the stages of slides 45 and 46 as well as the cam 48 are disposed concentric-ally with the stages of slides 31, 31a and cams 40, 40a, but at a different level: in Fig. 9, it will be seen that the slides 31, 31a are positioned above the slides 45, 46. But my invention provides also for the slides 45, 46 being above the slides 31, 31a.

In normal operation, the slides 45 and 46 are maintained clear from the cam 48 (in the position shown in Fig. 8) by means of latches 49 (Figs. 9 to 11) which engage a groove 60 provided in the proximity of the inner end of each slide 45 or 46, and will be described thereafter.

A rotating commutator 6| supplied from a suit,

able source ,of current energizes two electromag nets ,55l acting .upon pins .53 ,slidably housed ;in the .rim of the cam 48 qfor rendering inoperative the latches49 (Figs. .8.,to ;11,),.

Each pin .53 is pivotably connected to a pushmember 63 by a ,pin .66 (Fig. 8d). .Said pushmember is pivotably mounted at t lupon the upper face of the cam 48, and it is submitted to the .action or a mass 65, to which it is pivotably connected'at 61. The mass .65 is biassed outwardly by the centrifugal force, during the rotation of the cam '48., and consequently causes the pushmember 63 to be retractedinwardly, thus biassing the pin 53 inwardly (Figs. 8 and 8a) during the normal operation of the loom.

Under these conditions, the cam 48, turning with .the vertical shaft '56, is normally inoperativeas to the rollers 41.

But if it is desired to move all the warp threads towards the centre, for example to free the shuttle for the purpose of permitting, its re-loading, the rotating commutator ti (Figs. 8 and 9) is actuated and establishes an exciting current'in the electromagnets at the instant when the symmetrical crests-of the cam 48 are passing the axis ZZ :(Fig. 8). These electromagnets cause the pins 53 to emerge from the rim of the cam 48 against theaction of the mass 65 and push-member 63.

The mechanism for releasing the latches 49 is shown in part in Fig. 11.

In this figure, the bearing for mounting the slide 46 which at the same time carriesthe pivot 59 of latch 49 has been omitted. It will vbeseen from Figs. 9 to 11 that each latch 49 engages normally a groove 69 provided at the end .of the slide 46. As already stated, the electromagnet 5|, when energized, causes the pin .53 .to protrude outwardly from the rim of the cam 48, and the rotation of this cam in the direction of the :arrow brings the pin 53 into engagement with thelatch 49. This latch tilts about its pivot '59 and disengages the groove 60 of the slide 45, thereby freeing the slide. The operation of the slide 45 is similar. As the release 'is efiected just at the instant when the crest of the ,cam 48 is passing under the corresponding roller, this operation takes :place without shock, since the slide continues in this case to be held by its roller and by the crest of the cam in the position in whichgit had previously been maintained by the latch 49. The slides being free, the rollers 41 descend symmetrically along each of the two crests in proportion to the rotation of the cam 48.

It will thus be seen that, at the ,end of a half turn of the cam 28, all of the slides 45 .and 46 will be in their external positions and consequently also that the pulleys 43 will. allow relaxation of the cables 34 tensioning the springs 32 and displacement towards the centre, to .C, of the ends C of thesesprings.

'The movement shown diagrammatically in Figs. 1 to 4 has thus been realised.

From this instant, the exciting current for the electromagnets .5! is interrupted, whereby :the pins 53 are retracted into the rim of the cam 48 due to the action of the masses E5. Asthe cam 48 continues its rotation, the rollers zit? are acted upon by the second parts .of :itsitrack- The arrangement :which has inst :been .described :thus ,permitsaof the drawing towards the centre ofall the warp threads in sucha fashion as to .;free the ;-.s.hu t1e.

.It is to Joe noted that, as the control of the heddle 'by cam and rollers permits (as has been seen above) of 'thearresting at the centre of any one group of slides 31, 310. or 37?, 3ia, itis possible to arrest all of the groups and as a result to bring all the threads to rest towards the inside part of the reed without having recourse to the auxiliary mechanism described above with reference to the Figs. 8 to 11, at the same time suppressing all of the external return springs 32 (Figs. 1 to 4). In this case, the outer end B of each ,heddle A.-B would be directly-attached as at 44 tothe frame Q2 of the loom. Theloclring and release of the slides 3?, 375a would then be eiTected by means of the mechanism illustrated in Figs. 5 t F1- The rotating commutator 58 (Figs. '5 to 7) is actuated by suitable means which do not form a part of my invention. When the mechanism illustrated in Figs. 8 to 11 is associated with the mechanism illustrated in Figs. 5 to '7, the coinmutator .58 is designed for allowing the operation of the jloom according to the desired kind of weave, that is to say may be constituted in the manner of the known perforated sheets for weaving looms. But when .only the mechanism shown in Figs. 5 to '7 is used for retracting all the warp threads towards the centre of the loom inorder to uncover the shuttle, the rotating commutator 53 is designed -furt'l'lerrnore to keep all the warp threads retracted during the re-loading of the shuttle, and in this case it is actuated by any known safety device, for example of the kind disclosed and claimed in my copending U. S. Application Serial No. 23,607 filed April 25, 1948 which is now Patent No. 2,587,982.

The rotating commutator ti is actuated, when the shuttle is to be -re-loaded, by any suitable means, for example by the device disclosed and claimed in my aforesaid U. S. Patent No. 2,587,982.

What I claim is:

'1. In-a circular weaving loom icr weaving textile or metal threads means for normally controlling the opening of the shed formed .by-the warp threads and for drawing all of the warp threads towards the centre of the loom in order to uncover the shuttle, which include a number of heddles equal to that of the warp threads, means located inside the loom and adapted to produce at will a reciprocating movement of said heddles, springs operatively connecting said means to the inner ends of the corresponding heddles, :furthersprings secured to the outer ends of the :heddles, and means for .adjustably securing the .outerends of last mentioned springs in accordance -.with the desired opening and closing of the shed, the last mentioned springs being stronger than the first .mentioned springs.

2. In a circular weaving loom of the aforesaid type, heddles in number equal to that of the warp threads, an axialiloorn driving shaft a cam member actuated by said shaft and arranged in a plane perpendicular thereto, at least one internal track on said cam member, slides arranged in at least two different planes perpendicular to the loom :driving shaft and adapted to assume a reciprocating movement, rollers journalled in said slides and adapted to roll upon said internal tracks on the cam member, means :for tom-.- -porarily arresting at least some otsaid slides in their innermost position, a plurality of encased springs radially positioned, each connecting operatively at least one heddle with the corresponding slide, means for limiting the expansion of said springs, and means for connecting the outer end of the heddle to the frame of the loom.

3. In a circular weaving loom according to claim 2, external radial springs each attached to the outer end of at least one heddle, a plurality of cables, attached on the one hand to the outer end of the corresponding external spring and on the other hand to the frame of the loom, a plurality of idler and movable pulleys for said cables, each cable passing over at least one idler and over -,a movable of said pulleys, slides carrying said movable pulleys at their outer end and distributed by halves in two planes perpendicular to the loom driving shaft, bearings for mounting saidslides, a roller carried by each slide at its inner end, a cam actuated by said driving shaft, arranged in a plane perpendicular thereto and including aninternal track of symmetrical outlinei means for normally maintaining the rollers clear 'from oi the track on the cam, and means for :causing said rollers to cooperate with said track.

4.: a circular weaving loom according to claim' 3, a groove on each pulley carrying slide, a rocking latch cooperating with said groove and carried by the bearing in which is mounted the corresponding slide, an electromagnet system, means; for energizing same, pins in number equal to that of the electromagnets and slidably housed in the rim of the cam, for engaging said latches andftilting up same clear from the corresponding groove in the slide when protruding outwardly;

under the action of the energized electromagnets,

10 cam and a lower cam with internal tracks, offset by 180, actuated by the axial loom driving shaft and arranged in two parallel planes perpendicular thereto, four stages of superposed slides arranged in parallel planes perpendicular to the loom. driving shaft but disposed by pairs in different radial planes of the loom, a roller journalled on the upper face of each slide of the uppermost stage and cooperating with the upper cam track, a roller journalled on the lower face of each slide of the lowermost stage and cooperating with the lower cam track, means on each uppermost, and on each lowermost slide for positively driving the corresponding slide of each middle stage, bolts cooperating with notches in the slides for locking each slide in its innermost position, springs for biassing said bolts in engagement with the slides, electromagnets for retracting said bolts when energized, means including a rotating commutator for energizing at will said electromagnets, springs operatively connecting push-members pivotably mounted upon the upper face of the cam and pivotably connected at one end :to said pins for biassing normally inwardly said slides to the inner ends of the corresponding heddles, and means for limiting the expansion of said springs.

6. In a circular weaving loom of the aforesaid type, heddles in number equal to that of the warp threads, internal springs secured tothe inner ends of the heddles, tension limiting devices for said springs, external springs stronger than the internal ones and secured to the outer ends of the heddles, a first cam member actuated by the loom driving shaft for reciprocating the heddles through slides and rollers, and a second cam member situated below the first one for displacing at will the outer ends of the external spring through a mechanism including slides, rollers, cables and pulleys.

JEAN DUNOD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,016,370 Howarth Oct. 8, 1935 2,492,514 Ancet Dec. 27, 1949

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