Machine for printing fabrics

Abstract

 This machine comprises a table (1) and at least a driving roller (3) for driving a carpet (2) along a closed circuit (A, B, C, D, E, F, A), the carpet (2) presenting an inner wall touching the driving rollers (3) and guide rollers (30) and the closed circuit comprising mixed path lengths, straight-wound, wherein the closed wound lengths (A, B, D, E) are engaged by at least one driving roller (3) and by guide rollers (30) and the wound lengths (C, F) opened on the outside of said circuit are held within a chamber (4) by a drawing force (R) caused by a pneumatic depression (6).

Description

[0001] This present invention relates to a machine for printing fabrics, in particular a machine for printing fabrics on a table.

[0002] The prior art comprises machines for printing fabrics on a table wherein a fabric piece under printing is laid on a table and a truck, bearing printing means and generally being actuated by a control equipment, travels along the fabric piece. To meet the conventional lengths of the fabric pieces, the extension of said table may reach and exceed 80 meters and, therefore, it will be realized that the main disadvantage of such machines is the one of engaging a lot of space.

[0003] In order to obviate said disadvantage at least partly, machines have been proposed which have one or more fix printing stations and a carpet mobile along a closed circuit so that a fabric piece, long, for instance, 80 meters , may be stuck to a closed carpet of 80 meters ovehall extension, but mobile round a table approximately 40 meters long which, anyway, is still an undesirable extension.

[0004] A machine is also known wherein a fabric piece is wound up around a roller; said fabric piece is laid on a short table in an intermittent way, step by step; one or more printing stations are operative on said table; as said fabric piece is printed, it mooves to a drying tunnel. Such a machine does not require a long table, but the drying tunnel still takes much space.

[0005] Finally, the applicant discloses in the European patent application N^o 90 830.505. 5 a machine for printing a fabric on a table wherein a carpet which is driven along a closed circuit by a driving roller is guided by guide means to follow a first straight path on said table, a second winding path downstream said table and a third straight path, the totality of said paths equalling the conventional length of a fabric piece under printing; the main advantage of said machine resides in that, thanks to said winding path, a very reduced space is engaged with respect to the known machines, in horizontal directions; nevertheless, the drawback of this machine is a remarkable structural complication.

[0006] The present invention, as claimed, obviates the drawbacks of the prior art. The invention solves the problem to print long fabric pieces engaging a space resulting presently the minimum possible in the horizontal directions. It will be understood that the present invention is applicable to a machine for treating long strips or bands of flexible material like plastic, rubber, paper, in addition to fabric.

[0007] The invented machine conventionally comprises: a table; at least a driving roller for driving a carpet along a closed circuit which presents an upper length on said table, the carpet presenting an outer wall to which a fabric piece may be applied on and an inner wall touching driving rollers and guide rollers; at least a printing station over said upper length of the carpet; control and actuation operative means; in a new way, said closed circuit comprises mixed path lengths (straight paths - wound paths) wherein the wound portions which result closed in said circuit are engaged by at least one driving roller and by guide rollers and the wound portions which result opened on the outside of said circuit are engaged and held in position within a chamber by a drawer force caused by a pneumatic depression.

[0008] Preferably, said mixed path lengths are substantially comprised below said table.

[0009] The main advantage of this invented machine resides in that a space is engaged in plant less than the space angaged by a conventional machine for printing a fabric piece on a table, up to reducing the machine extension to 1/4 of the length of the favric piece.

[0010] Another advantage is that one of the two sides of the carpet, and therefore the exposed surface of the fabric piece, never touches the rollers or other mechanical parts so that the treated surface of said fabric piece is not disturbed or damaged.

[0011] Ways of carrying out the invention are described in detail herebelow with reference to the accompanying drawings which illustrate specific embodiments and wherein:

FIG. 1 is a diagrammatic side view,

FIG. 2 is a part perspective view,

FIG. 3 is a part side view and

FIGG. 4, 5, 6 are diagrammatic side views.

[0012] Fig. 1 shows a table 1 below the upper straight part of a carpet 2; two printing stations S1, S2 over said upper straight part; two opposite couples of driving rollers 3, each driven by a motor not shown, which drive the carpet 2 made of Kevlar fibers in the direction F1 along the close circuit A, B, C, D, E, F, A comprising the mixed path lenths, straight-wound, below the table 1 wherein each of the wound parts which are closed within said circuit (parts A, B, D, E) is engaged by a driving roller 3 and the wound parts which are open on the outer side of said circuit (parts C, F) penetrate in a chamber 4 having two opposite apertures and communicating through a duct 5 with an aspirator 6 able to held in position said moving wound parts C, F, each being guided into the corresponding aperture in said chamber 4 by idle guiding rollers 7 respectively adjacent to the upper and lower edges of said aperture. As an alternative to the idle rollers 7, the upper and lower edges of the apertures in the chamber 4 may be bent as shown in FIG. 4 by 70 in order to cause two sliding blocks for the carpet and simultaneously the necessary pneumatic seal. FIG. 3 will explain in more detailed way the action of aspirator 6 on said wound open parts.

[0013] FIG. 2 shows how the carpet 2 presents its own side edges sliding along the vertical inner walls in the chamber 4 (along low friction sliding means like vertical idle rollers, not shown) and the surface of the wound parts opened on the outside slide along idle rollers 7 to cause a sort of seal outward and make more effective the aspiration exerted from the aspirator 6 on said wound parts of the carpet.

[0014] It will be realized that the feature of holding in the proper position the wound parts opened on the outside in the circuit by means of a vacuum operated chamber prevents a fabric piece under printing from touching the driving rollers or guiding rollers, which touching would damage the printing.

[0015] FIG. 3 shows part of chamber 4 and how the latter works as a transmission roller for said open wound parts C, F. The pneumatic depression in the chamber 4 (in the illustrated case the depression is about 20,000 N/m^2, which may be provided from a standard aspirator) causes a drawing radial action on said wound parts C, F which is conventionally indicated by arrows F2; such action imparts a circular shape to said parts C, F (the circle has a diameter of about 80 centimeters); the summation of said radial actions is a resultant force R directed inward the chamber 4 and balances the tension T which holds under tension the length of carpet 2 between said chamber and the opposite driving roller. The aspiration and depression caused by the aspirator 6 in the chamber 4 are conventionally indicated by arrows F3.

[0016] FIGG. 4, 5, 6 show embodiments wherein the carpet 2 is driven by driving rollers 3, is guided by idle rollers 30 and has the open wound parts C guided by idle rollers 71 and respectively held, as already explained, in a chamber 41, 42, 43 provided with one, two, four apertures directed to the same direction, the chamber being associated with an aspirator 61. As said, according to FIG. 4, the pneumatic seal between the carpet and the chamber, at the upper and lower walls, is afforded bya sliding block 70 in said walls.

[0017] It will be realized that in any illustrated embodiments of the invention the closed circuit followed by the carpet is comprised within the horizontal perimeter of the upper circuit length; in other words, substantially all the circuit is over and below the table and does not engage space at the right and left sides of the table.

Claims

1. A machine for printing fabrics comprising a table (1); at least a driving roller (3) for driving a carpet (2) along a closed circuit (A, B, C, D, E, F, A) which presents an upper length on said table (1), the carpet (2) presenting an outer wall to which a fabric piece may be applied on and an inner wall touching the driving rollers (3) and guide rollers (30); at least one printing station (S1, S2) over said carpet upper length; control and actuation operative means for said driving rollers and printing stations characterized in that said closed circuit (A, B, C, D, E, F, A) comprises mixed path lengths, straight and wound paths, wherein the wound portions (A, B, D, E) which result closed in said circuit are engaged by at least one driving roller (3) and guide rollers (30) and the wound portions (C, F) which result opened on the outside of said circuit are engaged and held in position within a chamber (4) by a drawer force ( F2=R) caused by a pneumatic depression (F3) made in said chamber (4) by an aspirator means (6).

2. A machine according to claim 1 characterized in that the whole closed circuit (A, B, C, D, E, F, A) is substantally comprised within the horizontal perimeter of said upper circuit length over said table (1).

3. A machine according to claims 1 and 2 characterized in that the width of the carpet (2) equals the aperture of the chamber (4) wherein said carpet wound length (C, F) seal slides and at least one group comprising an upper idle roller and a lower idle roller (7, 71) is located in said chamber (4) in such a way that said rollers are tangent, respectively, to the upper and lower part of said chamber (4) in order the corresponding carpet wound length (C, F) to slide without friction on said idle rollers (7, 71), a pneumatic seal towards the chamber outside being afforded by the assembly comprising said idle rollers (7, 71), said carpet wound length (C, F) and said side, upper and lower walls of said chamber (4).

4. A machine according to claim 3 characterized in that the pneumatic seal between said carpet wound length (C, F) and said upper and lower walls is afforded by a bent (70) in the edges of said walls.

Drawing