US2099780A - Apparatus for weaving terry fabric - Google Patents

Description

1937. M. VAN DE CASTEELE 2,099,730

APPARATUS FOR WEAVING TERRY FABRIC Filed May 10, 1935 Zhvenim:

J K fi Patented Nov. 23, 1937 UNITED STATES PATENT OFFECE,

Marc Van de Casteele, Ronbaix, France Application May 10,

1935, Serial No. 20,866

In France May 12, 1934 6 Claims.

This invention has for its object improvements in processes for weaving looped tissues, more particularly terry fabrics. The invention is characterized by a device for the regulation of the opening forming the loop, so that the consumption of loop warp, which depends primarily upon the size of the opening, is always exactly in agreement with the predetermined loop warp feed, which will permit of applying to this warp a constant tension by means of an oscillating back beam counterbalanced by weights.

The length of loop warp supplied with respect to a length of basic warp Woven is called loss and this definite feed of looped Warp is obtained by a continuous distribution only operated under the tension of this warp.

The invention furthermore permits of weaving parts of the fabric without loops, without adjustment, and of recommencing automatically the manufacture of the looped fabric without any irregularity.

The accompanying drawing shows diagrammatically the application of the invention to a ioom with a hinged connecting rod, Figure 1 illustrating a method of forming a looped fabric, and Figure 2 being a detail View, partly in section, of a device connecting the feed roller with the draft cylinder.

Figure 3 shows an arrangement of the members permitting the automatic regulation of the opening which forms the object of the invention.

To facilitate the understanding of the drawing, each of the spindles fixed to the frame of the machine is indicated by a cross hatched round 5 spot.

In Weaving looped terry fabrics or the like, one method consists in inserting, for example, the two weft threads i and 2 of Figure l at a certain distance from the weft thread t previously in- 0 serted, and then a third weft thread 3 which will be beaten up against the fabric already made at the same time as the weft threads I and 2. On doing this, these three weft threads, in which the looped warp threads 5 are interlaced and to a certain extent held, will slide on the base warp which is kept tight, carrying with them the less tensioned loop threads, which will form, according to their interlacing, loops at the front or at the back of the fabric.

The term opening means that space which is temporarily left between the fabric already made and the weft threads and 2, and it will be easily understood that this is the principal factor determining the length of the loops, although the tension of the loop warp also has an important influence.

For a like opening, the stronger the tension of the loop warp the shorter the loops, for there will be produced a greater backward sliding on the Weft threads which hold them. This sliding cannot be eliminated by reducing the tension of the loop warps since the knots are then not formed at the back of the loops, but it cannot become too large since it then becomes irregular and the loops are not uniform in length although their mean length may be that which is desired.

It will therefore be seen that a suitable and constant tension of the loop warp is important for obtaining a good looped fabric. From what has been explained of the action of the tension of the loop warp, it may be stated that the length of the loops is approximately inversely proportional to the tension of its warp and approximately directly proportional to the size of the opening.

A third factor also has an influence, namely, the tension of the base warp, for the greater this is, the tighter will the loop threads be held, thus increasing the force of the interlacing of these with the weft threads which carry them along.

The size of the loops is, therefore, also approximately directly proportional to the tension of the base Warp and variations in the latter arising from the reduction of the diameter of the wound warp or from imperfections of braking will alter the length of the loops even in the case of a loop warp kept under a constant tension.

Furthermore, although the opening may be made constant from the mechanical point of View, it is not so from the point of view of efliciency with respect to the formation of the loops, for the following reasons:

It is known that in fabrics well supplied with threads and particularly with weft threads, these Weft threads are not moved into their final position at the first stroke of the lay which inserts them. There is a certain return of the fabric towards the back of the loom which is termed repulse or backing, so that the following strokes of the lay have a further compressing effect upon the weft threads already inserted until equilibrium is established with the forward movement of the fabric carried by the draft cylinder; nevertheless, this backing exists with each stroke of the lay in closely woven tissues and obviously results in reducing the opening mechanically obtained.

Thus, any variation of the backing will cause a variation of the actual opening and consequently of the length of the loops. Now, though this backing depends upon the number of weft threads, it also depends upon the size of these and upon the facility of insertion thereof, due, for

example, to their surface roughness, which roughness may vary according to the different treatments necessitated by the bleaching, dyeing or other operations.

Thus, all these properties of the weft will also influence the size of the effective opening.

In order nevertheless to obtain a regular loss, feed cylinders have been employed giving a' definite length of feed of the loop warp.v The ten.

sion of this warp thus depends upon the difference between the size of the eifective' opening and the length supplied, which'isnecessarily lessin:

warp and a constant tension in the lattercapable of easy regulation, it is proposed to act on the 7 causes 'ofthese variations of tension, that is to 30 say, pricipally on the variations of the effective opening which determines a greater or less draft of the loop warp. The devices which characterize the present invention have for their object to eliminate all the ;causes of irregularityby creating an automatic regulation of the loss of loops combined with the tension of the loop warp, the tension of the .base warp, and the facility of inserting the weft byacting automatically on the size of the opening; In the particular case where it is desired to manufacture a certain length of fabric without loops, a special device acts automatically on the feed of the loop warp. a 7

These devicescomprise: V V (a) A device controlling and limiting the feed of, the, loop Warp and a a (b) A regulating device varying the size ofwthe opening in such manner thatit is always in proper relation to the length of loop warp supplied, and .also, acting on the tension applied to this warp fand even, to a certain, extent, on the tension of thelbase warp.

The feedcylinder for the loop warp comprises lightly braked warprbeam 6, on which'this warp H .is wound, and a feed roller 1 covered with felt'or similar frictionalmaterial in such manner that there should be no slipping.

The roller does not cause the movement but is itself moved by the tension applied to the loop warp without, however, being able to exceed a definite ratioof rotation.

To this end, this roller 1 is mechanically connected with the cylinder 8 for drawing the woven fabric, through a transmission the ratio of which .may be regulated by changing the pinion 9, in such manner that to a particular amount of fabric wound upthere corresponds a particular feed quantity of loop warp. The number of teeth on the pinion! may be determined according to the length of-the loop warp supplied, with respect to the lengthof the base warp, that is to say, to the lossflof loop warp.

The particular feature of this connection resides in the fact that one of the transmission pinions is freely rotatable in one direction, that is to say, that if there were no draft of the loop warp, there would be no rotation of the roller 1, as shown by Figure 2.

The rotation of the roller I only occurs due to the tension applied to the loop warp by the back beam II! which is itself supported by a lever H counterbalanced by one or more weights l2 which are adjustable in position so as to regulate the tension of the .loop Warp and to obtain, after regulation, a constant tension on this warp. The lever I! may, as shown, be mounted to oscillate about the axis of the roller 1. V V

The opening regulator is controlled bythe displacementof the back beam roller and, consequently, of the lever l l which is connected to a part i3 forming a sliding shoe and having a groove M in which moves, with a certain amount of play, a block I5 hinged to a'lever I6. 7

A variation inthe position of this block causes a variation of the inclination of the lever and this inclination is transmitted by connecting rods I! to a lever 58, pivoted about a point l3, thus altering the position of .a pawl 2E] which is adapted to engage the pivot pin 2i and. thus modify, as is already known, the effective length of a connect ing rod 22'by flexing this connecting rodv into two 1 shots per loop for example, this cam 36 keyed on the shaft 3%": will make one revolution for three of the crank-shaft, the pawl will engage during. two revolutions. and will be disengaged. at the. third;.thus, the lay will insert two weft threads with opening and at the third will beat up all the three against thefabric already made, thus forming loops.

The variation in size of the opening is thus I obtained by the forward and backward movement of the sha t 3i carrying the pawl 29.

Furthermore, when the pawl 20 engages the pivot '25, the, effort required for the flexing of the connectingrod drawn back by the spring 29 exerts onthis pawl a tractive effect which is.

arranged to be greater than the contrary action of the springtil drawing back the lever [Band the shaft 3! towards the rear of the loom. On the engagement, the block 55 thus moves in the slot of the sliding shoe and comes to beareon a different surface, and on the disengagement, the spring jlfibrings the block back to its first position.

It will furthermore be seen that the engagement of the pivot 2| tends to diminish the opening, since it draws the pawl forward, and that the disengagement tends to increase itsinoe the spring 3!? draws it back.

These twov contrarytendencies are controlled by the position of the sliding shoe which follows the position of the back beam l0 without effortor reaction, since the play of the block in 9,099,786 compensate for the greater slip which would take place in the formation of the loops.

In the same way, if the tension of the base warp were reduced and if the wefting were altered for a similar difference of length between the loop warp and the base warp, there would be a different number of loops, and thus a change of length of these and an automatic correction of the opening.

As in the manufacture of terry fabrics, for example, it is necessary to make parts of the fabric without loops by means, for example, of the Jacquard or pattern mechanism, the pawl is caused to engage the end 39 of the lever 31 at the moment when the latter is in the position shown on the drawing.

At this moment, the pawl 20 not being in engagement, the action of the spring 30 is no longer counterbalanced by that of the spring 29 drawing back the connecting rods, as shown on the draw: ing, and the block l5 no longer disengages periodically the sliding shoe l3 which is kept fixed between its guides 33.

Since there is no longer any formation of loops, the back beam commences to move upwards; but the sliding shoe l3 cannot follow it especially since the adhesion of the block l5 in the slot M is increased by a fine serration made in the surfaces of the groove and on the sides of the block and there results a strong pull on the rod 25 which, through the lever 26 hinged at 21 on the lever H causes the brake 28 to act.

At this moment, the loose pinion in the transmission from the draft cylinder comes into operation and permits the roller 1, which is braked, only to supply the length of warp necessary for the weaving of the portion without loops.

At the moment of recommencing the looped weave, the sliding shoe is again dropped at each engagement of the pawl 20 with the pivot 2|, and the back beam Ill is thus liberated. The brake is released and the roller 1 resumes its normal unwinding for supplying the loop warp.

The consecutive weaving of portions of the fabric with and without loops does not necessitate a coupling taking up the pinion 34, since the length of loop warp not consumed in making the fabric without loops, is not fed by the roller 1 which is then braked and this under-consumption need not be transferred to the fabric with loops since the loss is calculated with respect to the fabric with loops and not with respect to the whole of the parts with and without loops.

The external portion of the loose wheel shown in Figure 2 receives its impulse from the roller 1,

whilst the inner part is given a definite movement from the cylinder 8 drawing the fabric.

It will be seen by the arrangement of the pawls that the exterior of the free Wheel can rotate less quickly than the interior when the roller 7 is braked, and at the same speed when this roller is not braked, but never more quickly.

There is thus obtained an absolutely automatic regulation of the opening and of the supply of looped warp and consequently an absolutely regular working without it being necessary to regulate from time to time the opening with respect to the tension of the various warps, even in the case of modification of the weft or of the prime materials employed.

Naturally the shapes and the details of construction and arrangement may be varied without departing from the scope of the present invention which applies equally to other systems also known in the weaving industry for obtaining the opening necessary for the manufacture of looped tissues, such as movable frames or reeds.

I claim: 1. In combination with a loom for weaving looped fabrics, particularly terry fabrics, means for continuously supplying loop warps, means for taking up the fabric woven in the loom, means controlled by said take-up means for determining the maximum length of feed of the loop warps, means for applying tension to said loop warps and means controlled from said tensionapplying means for varying the stroke of the loom lay.

2. A device for the automatic regulation of the opening forming the loops in looms for weaving looped fabrics, comprising in combination with a roller off which the loop warp is unwound, a movable back beam carried by levers counterbalanced by adjustable weights and having the loop warp passed therearound, variations in the traction of this warp arising from variations in consumption thereof being adapted to cause an alteration in the position of the back beam, a sliding shoe connected to control means adapted to effect a variation in the size of the opening, and means for transmitting the variation in the position of the back beam to the said sliding shoe.

3. In combination with a loom of the character described, a device regulating the opening forming the loops in the loom for weaving looped fabrics, comprising a back beam, hinged levers having said back beam mounted thereon, a sliding shoe having the motion of said back beam transmitted thereto by connection through said hinged levers, a block rotating about an axis, said sliding shoe having a slot formed therein acting on said block, pawls mechanically connected to said block, said pawls retaining the lay of the loom, articulated connecting rods connecting said sliding shoe with said pawls, and said sliding shoe modifying the position of said pawls for regulating the size of the opening by any alteration in the position of said shoe.

4. A device for the automatic regulation of the opening forming the loops in looms for weaving looped fabrics, comprising in combination with a roller off which the loop warp is unwound, a movable back beam carried by levers counterbalanced by adjustable weights and having the loop warp passed therearound, variations in the traction of this warp arising from variations in consumption thereof being adapted tocause an alteration in the position of the back beam, a sliding shoe connected to control means adapted to effect a variation in the size of the opening, braking means secured to the back-beam levers adapted to control the movement of the loop warp roller, and a rod connecting said braking means with the sliding shoe, whereby a movement of the back beam upwardly brakes the warp roller against the weight of the sliding shoe, through the intermediary of the connecting rod, said shoe releasing the brake whenever the back beam moves downwardly.

5. In a device as claimed in claim .4, a gear train between the loom driving means and the loop warp roller driving means, said gear train having a ratchet differential clutch whereby said clutch is inoperative whenever the loop warp roller speed equals that of the loom driving means, said clutch operating to add a tension on said warp when the consumption is high to cause oscillation of the back beam and releasing said tension when weaving fabric without loops.

6. In a loom of the character described, means for transmitting oscillations of a, hack-boom to the loop regulating moans of a. terry faljri cflloom, comprising a, rod c'o opcrating 'with th ,backheam a, sliding shoe having a, notched dg cam opening, a'membcr movable in'said'op'ening and having corresponding notches, an oscillating lever secured at one 'end to thcf novqbm n'o i bcr, a. second lever connected to sgid'firstll e ver'and niovabl e thgrovvith, and limiting means formed on"the"1ay,a "ho ok actuated by-'the*'second lever and 'adapted'for"engagment with said limiting manss as to limit themovement of the lay in correspondence to that of the back-beam through 'theinstifii nfitality of the'slidingshoe and cog rat lsw r r VAN DE CAS'IEELE.

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