FLUID-DRIVEN APPARATUS FOR FEEDING A FABRIC IN A PROCESS TUMBLER
A fluid-driven apparatus continuously feeds fabric in open-width form. The apparatus is associated in combination with a tumbler processing the fabric. The apparatus includes a tubular duct, with a substantially rectangular transversal cross section, has boundary walls which delimit an internal cavity inside the duct. A manifold supplies gaseous fluid into the duct through an opening formed in the top or bottom wall of the duct. Ports for the fluid extend in a direction longitudinal to the duct, into and out of the cavity. The manifold abuts the opening to divide the duct into two distinct stretches delimited by the manifold and by the ports. The manifold includes a diverter for selectively directing the fluid towards one of the stretches of the duct. A portion of one of the duct stretches is divergent in shape, with a transversal cross section increasing from the manifold to the respective end port.
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This invention relates to a fluid driven apparatus for feeding a fabric in a process tumbler.
Prior ArtCurrently used in the textile industry are process apparatuses, called “tumblers”, in which fabrics of various kinds are subjected to treatment, for example mechanical and/or heat treatment, to create characteristic and distinctive effects for different types of fabric. The fabric is fed—for example in open-width form and continuously—according to a method known in the industry, by means of an apparatus of this kind, which is equipped with a tubular duct whose transversal cross section is substantially rectangular and whose length is typically at least three times its width.
The duct comprises boundary walls which delimit an internal cavity inside the duct itself, ports for the passage of a gaseous fluid in a direction longitudinal to the duct into and out of the internal cavity and at least one lateral opening for the passage of the fluid in a transversal direction towards the internal cavity and made on the top and/or bottom wall of the duct.
A supply manifold for directing the fluid towards the tubular duct is abutted against the top and/or bottom opening of the duct, dividing it into two distinct stretches respectively downstream and upstream of its position.
Diverters associated with the supply manifold allow diverting the flow of gaseous fluid to one or the other of the two stretches of the duct which, depending on the direction fluid flow, operatively become delivery or suction duct stretches.
By effect of movement of the fluid supplied by the supply manifold, diverted and flowing along the duct cavity towards the outlet afforded by one of the two ports, the fabric, at the other port at the opposite end of the duct, is sucked into the duct cavity together with the air and is forced to move along the cavity from one end to the other under the action of, and in the same direction as, the air flow.
In the prior art, the tubular duct has walls which are equidistant from each other. That means the cross section of the duct through which the fluid flows is the same at all points of the duct.
Although these feed apparatuses are widely used in this industry, they are not free of disadvantages and, depending on the type of fabric processed, can lead to critical conditions which are anything but negligible.
In effect, when processing, for example, very stiff, coated fabrics, imitation leather or other material having a high surface friction coefficient, the fabric tends to stick to the duct very easily. Moreover, if the process also involves the use of hot air, the problem becomes even worse.
As a result of the difficulty of moving along the duct, the fabric downstream of the manifold which blows air into the duct tends to curl up on itself, to increase its overall dimensions and to gradually reduce the size of the passage through which the air in the duct can flow.
The residual flow passing through the duct becomes more and more turbulent, thus dissipating drive power and, as it loses carrying capacity, rapidly becomes unable to support and carry the fabric which eventually stops moving and occludes the duct.
DISCLOSURE OF THE INVENTIONThe aim of this invention is to overcome the above mentioned disadvantages. According to the invention, this aim is achieved by a fluid-driven apparatus for feeding a fabric and whose technical features are defined in the appended claims.
Further advantages of the invention will become apparent from the detailed description of a non-limiting example embodiment of such an apparatus, illustrated in the accompanying drawings.
In the drawings:
With reference to the accompanying drawings,
More specifically, the duct 2 has a tubular profile with a substantially rectangular cross section and is provided with boundary walls at the top and bottom (11a,11b) and sides (not illustrated) delimiting an internal cavity 12 inside the duct.
At opposite open ends of it, the duct is also provided with ports 9 and 10 for the passage of the fluid in the form of flows 5,6 directed longitudinally, one into and the other out of the duct 2.
Half way along it, the tubular duct 2 is provided with four further openings 13 formed in opposite pairs, passing through the top and bottom walls 11a,11b, of the duct 2. Connected to the openings 13 of the duct 2 is the manifold 14 which, thanks to its position—substantially half way along the duct 2—divides the latter into two component stretches 15a,15b of equal length, one of which is delimited by the manifold 14 and the port 9 and the other by the manifold 14 and the port 10.
According to the invention, at least one of the two stretches 15a,15b—or preferably both of them—is divergent in shape, with a transversal cross section which increases in size from the manifold 14 to the port 9 or 10 associated with the stretch 15a or 15b of the duct 2.
Small angles of divergence 16 have been found to be surprisingly optimal. Angles not greater than three sexagesimal degrees are preferable.
In
In use, the operation of the apparatus 1 may be described with reference to
It should be noted that the divergence of the stretches 15a and 15b, although only slight, produces a plurality of highly synergic, useful effects which allow the fabric 7 to be pneumatically supported and fed along the duct 2.
In effect, as is clear from
In other words, therefore, the divergence of the duct 2—all other conditions being equal—allows the fabric 7 to be fed much more effectively and under much more favourable conditions of resistance which are particularly useful with coated fabrics or resin-impregnated fabrics with high surface adhesiveness.
From
Claims
1. A fluid-driven apparatus for feeding a fabric in open-width form and continuously, the apparatus being associated in combination with a tumbler processing the fabric, the apparatus comprising: the manifold being equipped with diverting means for selectively directing the fluid towards one or the other of the stretches of the duct; wherein at least one portion of at least one of the stretches of the duct is divergent in shape, with a transversal cross section which increases in size from the manifold to the respective end port.
- a tubular duct with substantially rectangular transversal cross section, having boundary walls which delimit an internal cavity inside the duct;
- a manifold for supplying gaseous fluid into the duct through at least one opening formed in a top wall or a bottom wall of the duct;
- ports for passage of the fluid in a direction longitudinal to the duct, into and out of the cavity; the manifold being abutted against the at least one opening, at a position to divide the duct into two distinct stretches delimited by the manifold and by one of the ports, respectively;
2. The apparatus according to claim 1, wherein divergence of said portion of at least one of the stretches is obtained by inclining only the top wall relative to the bottom wall.
3. The apparatus according to claim 1, wherein at least one of the stretches is entirely divergent in shape, with increasing transversal cross section.
4. The apparatus according to claim 3, wherein both the stretches are entirely divergent in shape, with increasing transversal cross section.
5. The apparatus according to claim 1, wherein the divergent shape has an angle of divergence not greater than three sexagesimal degrees.
6. The apparatus according to, claim 1, wherein the fluid is thermally conditioned.
Type: Application
Filed: Mar 22, 2016
Publication Date: Feb 15, 2018
Applicant: BIANCALANI S.R.L. (Prato)
Inventors: Massimo BIANCALANI (Prato), Riccardo RAVAGLI (Pistoia)
Application Number: 15/559,726