Machines For The Continuous Manufacture Of Cloth By Superposing Several Layers Of A Textile Web

Abstract

The web is fed onto a horizontal surface moving parallel to the width of the web leaving the feed device. It is laid by alternate sweeping movements of the feed device in a relatively impervious enclosure having a slot for the incoming web lined therein and two flaps inside the slot oscillating to deflect the web and preserve a reduced pressure created inside the enclosure. The receiving surface is air-permeable at its longitudinal edges but impermeable at its central region.

Description

The invention relates to machines for the continuous manufacture of cloth by superposing several layers of a textile web, these machines comprising a feed device adapted to introduce the web into the machine, a substantially horizontal receiving surface, arranged below this device and adapted to be driven in a direction parallel to the width of the web leaving said device, and means arranged between the feed device and said surface to deposit the web on the latter by an alternate lateral sweeping and thus to form the cloth on this surface.

Due to the fact that the cloth already formed moves away parallel to the direction of the width of the web in proportion as the latter is deposited on the receiving surface by bands of equal widths and going alternately from right to left and from left to right over this surface, this cloth is constituted by a superposition of bands or layers of web, the number of which is proportional to the ratio between the speed of introduction of the web and the speed of displacement of the receiving surface and to the ratio between the width of the web and of the cloth.

Hitherto, the above said means were of a mechanical nature. Thus, in the machine known under the name "camel-back," the web passes over a roller, practically tangential to the receiving surface, on which is imposed a to-and-fro movement perpendicular to the width of the web, that is, to the direction of displacement of the receiving surface. However, mechanical solutions possess a number of drawbacks among which are difficulties of regulation, relatively noisy operation and insufficient speeds of cloth formation (actual upper limit : 50 to 55 meters/minute).

It is an object of the invention to overcome these drawbacks.

To this end, the machine according to the invention is characterized by the fact that the abovesaid means are constituted by a relatively impermeable enclosure which comprises : above the receiving surface, an elongated opening for the introduction of the web ; inside, two flaps limiting, by their respective upper edges, the large parallel sides of the opening and adapted to oscillate along these upper edges so that one occupies a substantially vertical position, for which its free or lower edge is at a small distance from the receiving surface, whilst the other occupies a withdrawn position for which its free edge is spaced both from this surface and from the vertical plane of symmetry of the said introduction opening for the web, and vice versa ; and introduction opening for the receiving surface alone ; an exit opening for this surface lined with the cloth ; means for creating a pressure drop between the introduction opening for the web and the inside of the enclosure ; and drive means for actuating the flaps in their oscillating movement ; and by the fact that the receiving surface is arranged to be permeable to air on its longitudinal edges but impermeable in its central region.

In this way, the portion of the web which enters through its feed opening is sucked towards the edge (permeable to air) of the receiving surface which is neighbouring to the flap in retracted position whilst the flap in substantially vertical position exerts on the cloth a slight pressure which holds it in place on the receiving surface in motion. It will be understood that the synchronized oscillating movement of the flaps actuates the sweeping movement sought for the web.

Perferably, the receiving surface is constituted by an endless belt which passes over parallel drive and guide rollers situated outside the enclosure, which facilitates the extraction of the cloth.

The abovesaid endless belt can be permeable to air over its entire surface and be supported inside the enclosure on a solid and fixed plate, of width less than that of the endless belt and than that of the cloth to be manufactured. Due to the solid plate, the endless belt behaves as if it was only permeable to air along its edges even though it may be perforated in a homogeneous manner, to facilitate its manufacture and reduce its weight.

Two of the said rollers, approximately tangential between themselves and to the outer wall of the enclosure, can be arranged on each side of the abovesaid exit opening, so as to enable the exit of the endless belt lined with the cloth whilst preventing air from entering the enclosure through this opening, in the case where this enclosure is placed under reduced pressure.

On both sides of the elongated web introduction opening, the enclosure can possess auxiliary openings arranged so as to be freed or obturated by the neighbouring flap according as the latter occupies its substantially vertical position or its retracted position. In this way, there is established through the auxiliary opening thus freed, a current of air which adds its effect to that of the flap in substantially vertical position to maintain the already formed cloth in position, on the side opposite that towards which the web arrives.

In order that the invention may be more fully understood, a preferred embodiment thereof is described below, purely by way of illustrative and non-limiting example, with reference to the accompanying drawings, in which :

FIG. 1 shows diagrammatically one embodiment of a machine constructed according to the invention, in vertical cross-section through a plane parallel to the width of the cloth formed ;

FIG. 2 shows the embodiment of FIG. 1 in vertical section along the line II--II of FIG. 1 ; and

FIG. 3 shows the same embodiment in perspective with portions cut away.

With regard to the machine as a whole, this is constructed so that it comprises a feed device 1 adapted to introduce the web A into the machine (in the direction indicated by the arrows f) ; a substantially horizontal receiving surface 2 arranged below the device 1 and adapted to be driven in a direction (the direction indicated by the arrows F) parallel to the width of the web A leaving the device 1 ; and means 3 arranged between the device 1 and the surface 2 to deposit the web on the latter by alternate sweeping and thus to form the cloth B on this surface.

According to the invention, the means 3 are constituted by an enclosure 4, relatively impermeable, which comprises :

above the receiving surface 2, an elongated opening 5 for the introduction of the web A ;

on the inside, two flaps 6 and 7 limiting, by their respective upper edges 6a and 7a the large parallel sides of the opening 5, these flaps being adapted to oscillate along these upper edges so that one (flap 6 in the Figures) occupies a substantially vertical position, for which its free or lower edge 6b or 7b (6b in the Figures) is at a small distance from the receiving surface 2, whilst the other (flap 7) occupies a retracted position for which its free edge 7b or 6b is separated both from this surface and from the vertical plane of symmetry (practically contiguous with the plane of section II--II of FIG. 1) of the said opening 5, and vice versa ;

a web introduction opening 8 for the receiving surface 2 alone ;

an exit opening 9 for this surface 2 covered with the cloth B ;

means 10 for placing the enclosure 4 under reduced pressure ;

and drive means 11 for actuating the flaps 6 and 7 in their oscillating movement.

In addition, the receiving surface 2 is arranged to be permeable to air on its longitudinal edges (i.e., parallel to the direction of its movement) but impermeable in its central region.

As shown in the Figures, the enclosure 4 can have an approximately parallelopipedic shape with a bottom 12, a front wall 13 provided with the opening 9, a rear wall 14 provided with the opening 8, two lateral walls 15 and a roof 16 upwardly convex or with a double slope, the central upper portion of this roof being provided with the opening 5. The flaps 6 and 7 are borne respectively by axles 17 and 18 pivoted in the walls 13 and 14, these axles being situated near the upper edges 6a, 7a of the flaps.

The means 10 for placing the enclosure 4 under reduced pressure can be constituted by a blower 19 housed in a passage 20 which is adapted to one of the walls of the enclosure, for example one of the lateral walls 15, and which penetrates as far as about the center of the enclosure, as shown in FIG. 1.

As for the means 11 for driving the flaps 6, 7, they can be constituted by a cross element 21, of which the horizontal arms are pivoted respectively on two identical parallel levers 22 keyed respectively on axles 17 and 18 and of which the vertical bar is provided with a groove 23 also vertical, and by a drive shaft 24, parallel to the shafts 17, 18, on which is fixed a lever 25 bearing a pin 26, which is engaged in the groove 23. It will be understood that the levers 22 constitute two sides of the parallelogram of which a third side, defined by the shafts 17, 18, is horizontal and that consequently the other side constituted by the arms of the cross 21 is held horizontal in the course of its oscillations under the action of the pin 26. The continuous rotation of the shaft 24 hence causes oscillation of the flaps 6 and 7 in the same direction and with the desired angular displacement.

The receiving surface 2 is constituted by an endless belt 27 which passes over parallel drive and guide rollers situated outside the enclosure 4. As shown on the Figures, it can have five rollers 28 situated inside the endless belt, one of them at least being a drive roller. Four of these rollers can be arranged respectively at the corners of the enclosure 4 and the fifth roller in the same horizontal plane as the upper rollers and at a distance from the front wall 13, so that the surface 2 has the most favourable extent for the extraction of the cloth.

The endless belt 27 can, itself, be permeable to air only on its edges. However, it is more advantageous for it to be entirely permeable to air and to rest inside the enclosure 4 on a solid and fixed plate 29, of width less than that of the endless belt 27 and than that of the cloth B.

Two rollers, namely one of the rollers 28 and a roller 30, approximately tangential between themselves and to the front wall 13 of the enclosure, are arranged on both sides of the exit opening 9 and their axles are borne by solid plates 31 contiguous with the lateral walls 15 and projecting with respect to the front wall 13.

On each side of the web introduction opening 5, the roof 16 of the enclosure has auxiliary openings 32 arranged so as to be freed or obturated by the neighbouring flap 6 or 7 according as the latter occupies its substantially vertical position (flap 6 in FIGS. 1 and 3) or its withdrawn position.

The feed device 1 can be constituted either (as shown) by a pair of rollers 33 of which one is driven through its shaft, or by a simple deflection bar situated downstream of a machine for forming the web A.

Lastly, it is advantageous to place between the feed device 1 and the opening 5 a hopper 34, with a convergent profile, leading into the said opening, so that the air current is accelerated at the level of the latter.

The machine which has just been described operates in the following manner.

The web A is introduced continuously by the device 1 and forms a strand free between this device and the cloth B already formed. In the position illustrated in FIGS. 1 and 3, the flap 6 fills two roles : on one hand, it exerts on the cloth B a slight holding pressure which does not interfere with the advance of the latter in the direction of the arrow F (FIGS. 2 and 3) and, on the other hand it isolates, with the plate 29, two chambers above the surface 2. The chamber in which the free strand of the web occurs communicates, through the edge of the endless belt 27 which extends beyond the plate 29 (right hand edge in FIG. 3), with the lower portion of the enclosure 4 which is placed under reduced pressure by the means 10. By reason of the difference in pressure which exists between the two surfaces of the web, the latter is drawn towards the edge concerned of the belt 27 on which it is deposited flat. At the same time, the opening 32, which is liberated by the flap 6, allows a current of air to pass into the second chamber which flattens the portion of the cloth B which extends beyond the plate 29 against the belt 27.

Then, the means 11 rocks the flaps 6 and 7 towards a position symmetrical with that of FIGS. 1 and 3, which moves the web towards the left of these Figures, and so on. For an observer at the surface 2, there is thus obtained a zigzag movement of the web, the result of which is a cloth formed of several layers of web.

The opening 8 (FIG. 2) has dimensions just sufficient to permit the passage of the endless belt and hence does not interfere with the establishment of the reduced pressure inside the enclosure 4. As for the opening 9, which is necessarily larger since it must allow the cloth B also to pass, it is rendered impermeable by the pair of rollers 28, 30 in cooperation with the plates 31. It is clear that the lower strand of the belt 27 does not have to pass through the enclosure 4 but passes below the lower wall 12.

This machine is capable of numerous adjustments. In particular, the flaps 6 and 7 can have a width (or dimension perpendicular to their respective axles 17, 18) adjustable as a function of the thickness of the cloth B. In addition, the mutual angular displacement of the flaps 6 and 7 can be adjusted according to operating needs.

In a given machine, the width of the cloth B can be regulated by acting on the ratio between the speed of introduction of the web A and the number of beats of the flaps in unit time. Finally, by acting on the blower 19, the reduced pressure in the enclosure 4 can be adapted to the permeability of the web A and to its mechanical strength.

This machine is particularly useful in the case where the web is formed of a non-woven textile.

As is self-evident and as emerges already from the foregoing, the invention is in no way limited to those of its types of application, nor to those embodiments of its various parts, which have been more especially indicated ; it encompasses, on the contrary, all modifications. In particular :

means adapted to create a pressure drop between the introduction opening 5 and the inside of the enclosure 4 could be arranged to create an increased pressure at the level of the opening 5 or of the hopper 34, the blower 19 then being eliminated;

the drive means 11 could be arranged with a view to driving the flaps 6 and 7 in an intermittent movement making them pass suddenly from one to the other of their extreme positions ;

the flaps 6 and 7, instead of being flat as shown in FIGS. 1 and 3, could be curved or skew.

Claims

I claim:

1. Machine for the continuous manufacture of cloth by superposing several layers of textile web, comprising a feed device for introducing the web into the machine, a moving receiving surface having longitudinal edges and a central portion situated in a substantially horizontal plane and movable in a direction situated in said horizontal plane, means arranged between the feed device and said receiving surface to deposit the web on the receiving surface by alternate lateral swinging movements and thus to form the cloth on said surface, said means being constituted by a relatively pressure-tight enclosure which comprises: above the receiving surface, an elongated opening for the introduction of the web and having a vertical plane of symmetry; inside the enclosure, two elongated flaps defining, by their respective upper edges, the longer parallel sides of said elongated opening and adapted to oscillate along said upper edges so that one flap and then the other flap alternately occupies a substantially vertical position, in which its free or lower edge is at a slight distance from said receiving surface, whilst the other flap occupies a retracted position in which its free edge is spaced both from said receiving surface and from said vertical plane of symmetry; an entry opening in a first outer wall of the enclosure for the entry of the receiving surface alone; an exit opening in an outer wall of the enclosure opposite said first outer wall for the exit of said receiving surface lined with the cloth; means for creating a pressure-drop between the web-introduction opening and the inside of the enclosure; and drive means to actuate the flaps in their oscillating movement and to move the receiving surface from the entry opening to the exit opening; the receiving surface being permeable to air at its longitudinal edges but impermeable in its central region, auxiliary openings being arranged on each side of the elongated web-introduction opening at the side remote from said vertical plane of the corresponding flap so as to be freed or obturated by said corresponding flap according as the latter occupies its substantially vertical position or its retracted position.

2. Machine according to claim 1, wherein the means for creating a pressure-drop are means producing a reduced pressure in the enclosure.

3. Machine according to claim 1, wherein the receiving surface is constituted by a portion of an endless belt which passes through said entry and exit openings,over parallel drive and guide rollers situated outside the enclosure.

4. Machine according to claim 3, wherein the endless belt is entirely permeable to air through itself and rests inside the enclosure on a solid and fixed plate, of width less than that of the endless belt.

5. Machine according to claim 3, wherein two of the said rollers, approximately tangential between themselves and at said opposite outer wall, are arranged on each side of said exit opening, so as to enable the exit of the endless belt lined with cloth whilst preventing air from entering into the enclosure through said exit opening, wherein the means adapted to create a pressure-drop are means producing a reduced pressure in the enclosure.

6. Machine according to claim 1, including a hopper with a convergent profile placed between the feed device and the web-introduction opening, leading into said latter opening.