Claims:
What is claimed is
1. A device for producing a nonwoven carpet made from two backing layers coated with glue and fed into a well and a set of threads between the loops, said device comprising, in combination, folding blades acting alternately upon the set of threads to form loops between the layers, rods, each folding blade being fixed to the free end of a rod, levers, each rod being pivotally connected at its other end to a lever, shafts, said levers being fixed to said shafts, bearings supporting said shafts for rotation, other levers pivotally connected with said rods intermediate their lengths, third levers pivotally connected with said other levers, bearings supporting said third levers, rods connected with said shafts for imparting angular displacements to the shafts, cams actuating said rods, and means actuating said cams to maintain one folding blade temporarily in its lowermost position while a second folding blade starts its downward movement and deviates the set of threads.
Description:
The present invention is concerned with a device for the production of nonwoven carpets.
Devices have already been provided for the production of nonwoven carpets, wherein two separate backing layers are unrolled from two spools and whereby these backing layers are fed parallel to each other with a relatively small spacing into a well, both layers having been previously coated with glue in such manner that the gluecoated surfaces of aforesaid layers face each other in aforesaid well.
In this known device a series of lined-up threads which are unrolled from a common loom are fed into aforesaid well, whereby blades are provided opposite the upper edges of aforesaid well; each of which can act upon a ridge of the well so as to push aforesaid threads alternately to one or to the other side, thus forming loops which are alternately pressed into place in aforesaid coatings of glue.
In these devices, after the glue has hardened so that aforesaid loops are solidly fixed upon the backing layers, the product is cut through longitudinally so as to produce two separate velvet carpets.
In devices of this kind it sometimes happens, that in the course of the pressing into place of one loop by one of aforesaid blades, the loop previously formed by the second blade is pulled loose from its glue coating, so that irregularities can occur in the carpets.
In order to eliminate this drawback it has already been suggested, for the folding of aforesaid loops, to make use simultaneously of the actual folding blades as well as of auxiliary blades which, on the one hand facilitate the formation of the loops, and on the other hand maintain the loop which has just been formed.
Such a combination of folding and auxiliary blades is known for instance in a machine wherein a series of threads are folded loop-shaped into a well.
Attempts have also been made for applying such auxiliary blades to the aforementioned devices in which the loops are formed directly upon the backing layers in the well. Various difficulties do however arise during this application.
Such a construction is indeed rather complicated, requires a perfect synchronisation of the folding and of the auxiliary blades, etc. Moreover, special precautions have to be taken for preventing the auxiliary blades from coming into contact with the glue applied to the backing layers.
An object of the present invention is the provision of a device which totally eliminates the aforementioned as well as other drawbacks of the existing devices.
For this purpose, the present device mainly consists in a construction wherein aforesaid folding blades are each connected to a system of pivoting levers, whereby each system is controlled by a system of cams or the like which temporarily maintain one folding blade in its lowest position whilst the second folding blade starts its downward stroke in order to deviate the set of threads.
In order to show the characteristics of the present invention more clearly, a description is given below, without the slightest intent of limitation, of a preferred form of embodiment of such a device for the fabrication of nonwoven carpets, whereby reference is made to the appended drawings in which:
FIGS. 1 to 6 schematically show the kinetic movements of the folding blades, as they are used in the device according to the present invention;
FIGS. 7 to 12 respectively show enlarged views of the parts indicated in FIGS. 1 to 6 by F7 to F12;
FIG. 13 shows a diagram of the movements carried out by the folding blades of the device according to FIGS. 1 to 13;
FIG. 14 is a larger scale illustration of an embodiment of the device according to this invention;
FIG. 15 is a schematic topview according to arrow F15 of FIG. 14.
As shown in the accompanying Figures, the movements of the actual folding blades 1-2, are produced in that these folding blades 1-2 are firmly attached to rods 3-4, whereby these rods are each fixed by means of pivots, 5-6 and 7-8 to levers 9-10 and 11-12.
Levers 9 and 11 are pivotally fixed at their other end upon pivots, 13 and 14, whilst levers 10 and 12 are pivotally connected at their other end by means of pivots 15-16 with levers 17-18, which at their other ends are fixed to pivots 19 and 20. The pivots 13-14 and 19-20 are fitted in bearings which are fixed with respect to the machine.
The movements of aforesaid folding blades 1 and 2, are determined in such a way that they act upon the ridges 21-22 of the well 23 in which the backing layers 24-25, and the loops 26 are fed.
Finally, in this form of embodiment, the various movements are obtained by means of cams, 27-28 and 29-30, which, by means of guide rollers 31-32 and 33-34 determine the angular position of rods 35-36 and 37-38.
The latter are in their turn fixed to aforesaid pivots 13-14 and 19-20, so that the modification of the angular position of one of rods 35 to 38 causes the corresponding levers 9-11-17 and 18 to be angularly displaced, thus appropriately causing the displacement of aforesaid folding blades 1-2.
Cams 27-29 are fixed upon shaft 39 and cams 28-30 upon shaft 40.
The operation of this device is very simple and is as follows.
Both blades 1 and 2 act successively upon the ridges 22 and 21, of aforesaid well 23. The movement of the folding blades 1 and 2 with respect to each other is such, that when for instance blade 2 has just formed a loop, see FIG. 7, folding blade 1 is in its retracted position, after which, whilst blade 2 remains against ridge 21, blade 1 is brought forward almost against blade 2 and this in such manner that threads 26 have already been formed for the pressing in position of the following loop before the previous loop is released by blade 2.
At this moment folding blade 1 is maintained in this position whilst blade 2 is retracted, see FIG. 9.
When both blades are in the position shown in FIG. 9, blade 2 will move further backwards, whilst blade 1 forms a loop and brings the latter toward ridge 22, see FIG. 10.
Subsequently, blade 2 is brought in identical manner against blade 1 in order to prepare the next loop, see FIG. 11, whereby this blade is maintained in this position until blade 1 has moved backwards, see FIG. 12. Blade 1 is next brought back to the position shown in FIG. 7.
In FIG. 13 the diagrams have been drawn of the paths followed by blades 1 and 2 in the course of this operation, whereby the path of blade 2 is shown in solid line whilst the path of blade 1 is shown in striped line.
According to the present invention, the movements of blades 1 and 2 are determined in such a way that the paths followed correspond to diagram A B C A for blade 2 and to diagram A 1 B C 1 A 1 for blade 1.
The discussion concerning the diagrams of FIG. 13, will start for the sake of clearness from the position shown in FIG. 7. In this position blade 1 is located in point A 1 and blade 2 in position C.
Blade 2 will remain for instance during one-fourth turn of shaft 40 in this position, whilst during this time blade 1 will move from point A 1 along B to D 1 , thus already preparing the following loop whilst blade 2 maintains the preceding loop pressed into the mass of glue upon backing layer 24.
Thus during the preparation of a new loop the previous loop cannot be pulled loose.
Next, blade 2 will retract from C to A, after which blade 1 will be further displaced to C 1 thus forming the new loop. The movement of blade 1 along path D 1 C 1 is preferably given a circular shape, with ridge 21 as center, so that the threads remain under constant tension during the formation of the loop, without having to be subjected to pull.
Thus the new loop is formed whilst the previous loop cannot be pulled loose.
At this moment, the position is reached which is shown in FIG. 10 and where blade 2 moves from A along B to point D, so as to form a new loop in a similar manner according to a circular path D-C with ridge 22 as center.
According to the form of embodiment of FIG. 14 the blades shall each be maintained during one-fourth turn of shafts 39 and 40 in their respective locations C and C 1 . The displacements from C to A and from C 1 to A 1 will also take one-fourth turn of shafts 40 and 39; the displacements A 1 -B-D 1 and A-B-D will also occur during one-fourth turn and the displacements D 1 -C 1 and D-C in the course of the last one-fourth turn of shafts 39 and 40.
It is perfectly obvious that aforesaid rotations may be modified in any appropriate manner.
It is also quite obvious that the angular displacements of aforesaid pivots 13-14 and 19-20 can be obtained in any manner whatever, such as for instance by means of jacks, electromagnets, etc.
In this form of embodiment, the paths D-C and D 1 -C 1 are preferably of circular shape the centers being the ridges 22 and 21, although these circular paths could just as well be drawn around centers which are located higher or lower than the horizontal plane which passes through the points C-C 1 , whereby in such cases for instance the walls of well 23 should be made diverging in the one or in the other sense.
The movement of the folding blades is also by no means limited to the paths as shown in the diagrams of FIG. 13. In fact the movements of the folding blades can follow any appropriate path, whereby said path can be brought about by any appropriate means.
It has been shown in practice that the device described above permits the production of very close carpets, with upright bristles.
It does however appear, that with some sorts of threads, the carpets produced sometimes showed "wavelets," this being probably due to the twisting of the threads.
In order to prevent this unfavorable effect, it will be sufficient, according to the present invention, to pass threads 26 through reed 41 and to displace this reed linearly each time that one of blades 1,2 leaves the other (see FIGS. 9 and 12). These sliding movements can be obtained for instance by the co-operation of a cam 42, driven by shaft 43, a lever 44 which rocks around pivot 45 and is provided with a guide roller 46 and a rod 47. Guide roller 46 is maintained against cam 42 by means of a spring 48.
The present invention is by no means limited to the example described and to the form of embodiment illustrated by the appended drawings, but extends to all devices in which one folding blade maintains a loop pressed in position whilst the other blade prepares the next loop.