EP3095906A1

EP3095906A1 - Machine for steaming fabrics

Info

Publication number: EP3095906A1
Application number: EP16169217.3A
Authority: EP
Inventors: Ahmet Turan HASBAY; Tamer Hasbay
Original assignee: Has Trade Srl
Current assignee: Has Trade Srl
Priority date: 2015-05-19
Filing date: 2016-05-11
Publication date: 2016-11-23

Abstract

A machine for steaming fabrics, comprising a box-like enclosure (2) that defines inside it a treatment chamber (3) that accommodates:
- a main chain conveyor (4), composed of a pair of side-by-side chains and extended along a closed path that has a substantially horizontal advancement branch (7) arranged in an upper region of the treatment chamber (3);
- a secondary chain conveyor (5), composed of a pair of side-by-side chains and extended along a closed path that is superimposed laterally on the path of the main chain conveyor (4) at least proximate to the ends of the advancement branch (7);
- a storage chain conveyor (6), composed of a pair of side-by-side chains and extended along a closed path;
- a plurality of rollers (11) for conveying the fabric (12).

The chain conveyors (4, 5, 6) are provided with pairs of supports (43, 44, 45) that can be engaged detachably by end regions of the conveyor rollers (11);
the machine further comprises:
- means (13) for feeding the fabric (12) to be treated to conveyor rollers (11) arranged on the secondary chain conveyor (5), the feeder means (13) being located proximate to a first end of the advancement branch (7) of the main chain conveyor (4);
- means (14) for removing the treated fabric (12), which are arranged proximate to a second end, opposite the first end, of the advancement branch (7) of the main chain conveyor (4);
- means (15) for transferring the conveyor rollers (11) from the secondary chain conveyor (5) to the storage chain conveyor (6) and vice versa;
the storage chain conveyor (6) is arranged below the advancement branch (7) of the main chain conveyor (4).

Description

The present invention relates to a machine for steaming fabrics.
Machines for steaming fabrics are known. Such machines are used in the textile fiber processing industry, specifically in the field of fabric printing (hereinafter "printing"), and are usually identified by the term "steamer".
The steamer, which can be considered the key machine in any every printing facility, has undergone a slow and constant evolution that has affected the choice of materials suitable for construction, the way of conveying the goods, the control of process temperatures, the automation of operating parameters and, not least, the computerized recording of processes.
The steaming process has the purpose of stably fixing the colors to the fiber of a fabric by utilizing the physical properties of water vapor, which heats the fabric quickly, further adding humidity by condensation. The combined action of temperature and humidity diffuses within the fibers the film of color that has been deposited superficially with a previous process.
Steamers of a known type usually comprise a box-like enclosure, made of stainless steel plates, which delimits a treatment chamber adapted to contain the steam required for the fixing process.
All the mechanical devices needed to convey the fabric from the inlet to the outlet are accommodated within this chamber.
The conveyance of the fabric through the steamer occurs usually with hanging loops, which ensure the absence of tension, deposited on a plurality of conveyor rollers that are anchored to or supported by endless chain conveyors (i.e., conveyors that are extended along paths that are closed in a loop).
Some types of steamer comprise a main chain conveyor, which is composed of a pair of side-by-side chains and is extended along a closed path which has a substantially horizontal advancement branch arranged in an upper region of the treatment chamber, and a secondary chain conveyor, which is composed of a pair of side-by-side chains and is extended along a closed path which is superimposed laterally on the path of the main chain conveyor proximate to the ends of the advancement branch thereof. The main chain conveyor and the secondary chain conveyor are provided with pairs of supports, which can be engaged by the longitudinal ends of the conveyor rollers so as to move said conveyor rollers within the treatment chamber.
Substantially, the fabric to be treated is introduced in the treatment chamber by a conveyor belt, which in each instance defines a loop of fabric that is picked up by a conveyor roller that is supported by the secondary chain conveyor. In each instance, a conveyor roller with the loop of fabric is transferred to the main chain conveyor, the advancement speed of which is a function of the retention time in the treatment chamber that is required for correct steaming of the fabric. Proximate to the end of the advancement branch of the main chain conveyor, the fabric passes onto a roller system, which extracts it and removes it from the treatment chamber. The conveyor rollers that in each instance remain without fabric are transferred again onto the secondary chain conveyor, which returns them proximate to the inlet of the treatment chamber, where they receive a new loop of fabric and the cycle continues, keeping constant the number of loops of fabric inside the steamer.
A steamer that conveys the printed fabric in the manner described above currently allows to process a very wide range of fabrics, from the most delicate to the heaviest, without exhibiting particular problems in terms of result on prints provided with mechanical equipment (carriages, flatbed machines, rotary machines, etc.).
In steamers of the type described above, the supports for the conveyor rollers of the main chain conveyor are mutually spaced so that the center distance between two contiguous loops of fabric is 101 mm. Since the production capacity of the steamer depends exclusively on the amount of fabric that the treatment chamber can contain, this distance allows to maintain the dimensions of the steamer within acceptable limits even in the construction of steamers with a large capacity.
The development of modern printing processes performed with inkjet machines (digital printing) has revealed problems for which the manufacturers of steamers seek solutions. One of the main problems is the contact friction that the fabric, arranged in a loop, undergoes during the passage through the treatment chamber in advancing along the advancement branch of the main chain conveyor. In order to solve this problem, it is necessary to increase the distance between the loops along the advancement path of the main chain conveyor.
Users require steamers with acceptable capacity and dimensions in order to have significant hourly production rates and meet the requirements of mechanical printing, but treat in the same steamer fabrics printed with inkjet machines. The need has thus arisen to devise a technical solution that allows to increase, when required, the center distance between the loops.
A known solution to the problem described above is the possibility to remove one conveyor roller every two on the main chain conveyor. A consequence of this solution is that in the steamer there are conveyor rollers that are no longer used in the conveyance of the fabric and must be parked inside the steamer.
In currently commercially available steamers that use this solution, inside the steamer there is a storage chain conveyor onto which the unused conveyor rollers are transferred by the secondary chain conveyor.
In these steamers, the storage chain conveyor is arranged in line with the main chain conveyor and is accommodated in an extension of the treatment chamber on the fabric exit side. Transfer from the secondary chain conveyor to the storage chain conveyor is performed by means of a lever mechanism. The storage chain conveyor is extended along a path with numerous S-shaped bends, with the purpose of containing as much as possible the increase in space occupation of the machine that is required to contain it.
Although these steamers work, they suffer drawbacks.
First of all, the presence of the storage chain conveyor increases significantly the overall space occupation of the machine. Furthermore, it is well-known that assemblies on sliding bearings, ball bearings, mechanical chains immersed in steam, if they remain stationary for a long time, tend to seize and the extension of the storage chain conveyor on multiple S-shaped paths requires several guiding gears mounted on rolling pivots.
Moreover, the lever mechanism, due to the way in which it is designed, is a system that requires frequent maintenance interventions.
The aim of the present invention is to solve the problems described above, by providing a machine for steaming fabrics that allows to increase, when required, the center distance between the loops of fabric being treated and can have, for an equal performance, a reduced plan space occupation with respect to fabric steaming machines of the known type that offer this possibility.
Within this aim, an object of the invention is to provide a machine for steaming fabrics that ensures high reliability in operation while requiring reduced maintenance interventions.
Another object of the invention is to provide a machine for steaming fabrics that is capable of reducing the number of loops of fabric being treated and restore them when required rapidly and precisely.
A further object of the invention is to devise a machine for steaming fabrics that can be manufactured with competitive costs.
This aim, as well as these and other objects that will become better apparent hereinafter, are achieved by a machine for steaming fabrics, comprising a box-like enclosure that defines inside it a treatment chamber that accommodates:

a main chain conveyor, composed of a pair of side-by-side chains and extended along a closed path that has a substantially horizontal advancement branch arranged in an upper region of said treatment chamber;
a secondary chain conveyor, composed of a pair of side-by-side chains and extended along a closed path that is superimposed laterally on the path of said main chain conveyor at least proximate to the ends of said advancement branch;
a storage chain conveyor, composed of a pair of side-by-side chains and extended along a closed path;
a plurality of rollers for conveying the fabric;

means for feeding the fabric to be treated to conveyor rollers arranged on said secondary chain conveyor, said feeder means being located proximate to a first end of said advancement branch of the main chain conveyor;
means for removing the treated fabric, which are arranged proximate to a second end, opposite said first end, of said advancement branch of the main chain conveyor;
means for transferring said conveyor rollers from said secondary chain conveyor to said storage chain conveyor and vice versa;

Further characteristics and advantages of the invention will become better apparent from the description of a preferred not exclusive embodiment of the machine according to the invention, illustrated by way of nonlimiting example in the accompanying drawings, wherein:

Figure 1 is a partially sectional schematic side elevation view of the machine according to the invention with all the conveyor rollers arranged on the main chain conveyor;
Figure 2 is a partially sectional schematic view of the machine according to the invention, taken from the fabric inlet side;
Figure 3 is a partially sectional schematic view of the machine according to the invention, taken from the fabric exit side;
Figures 4a to 4e show schematically the operation of the transfer means in transferring a conveyor roller from the secondary chain conveyor to the storage chain conveyor;
Figures 5a to 5e show schematically the operation of the transfer means in transferring a conveyor roller from the storage chain conveyor to the secondary chain conveyor;
Figure 6 is a schematic front elevation view of the transfer means of the conveyor rollers;
Figure 7 is a view of the machine, similar to Figure 1, but with part of the conveyor rollers arranged on the storage chain conveyor.

With reference to the figures, the machine according to the invention, designated generally by the reference numeral 1, comprises, in a per se known manner, a box-like enclosure 2 that is made for example of stainless steel plates and defines internally a treatment chamber 3 which accommodates: a main chain conveyor 4, a secondary chain conveyor 5 and a storage chain conveyor 6.
Each one of the chain conveyors 4, 5, 6 is composed of a pair of chains that mesh with corresponding pairs of pinions supported by shafts which are supported, so that they can rotate about their corresponding axes, which are arranged horizontally and mutually parallel, by a supporting structure that is arranged inside the box-like enclosure 2 or is integrated therewith. The pinions define, for each chain, a corresponding closed path.
The expression "pair of chains" is understood to reference hereinafter two chains which, by meshing with corresponding pairs of pinions, are extended along two identical paths, each arranged on a corresponding vertical plane so that the two paths are mutually aligned laterally and are spaced laterally with respect to each other. For the sake of simplicity, in the accompanying drawings the two pinions of a same pair of pinions have been designated by a same reference numeral. Furthermore, the expression "path of a chain conveyor" is understood to reference the path followed by the corresponding pair of chains as a whole, i.e., determined by the pair of identical paths, arranged on two parallel vertical planes, followed by the chains of each chain conveyor.
The axes of the various pinions, with which the chains of the chain conveyors 4, 5, 6 mesh, are all horizontal and mutually parallel.
The main chain conveyor 4 is composed of a pair of side-by-side chains and is extended along a closed path that has a substantially horizontal advancement branch 7, arranged in an upper region of the treatment chamber 3. Preferably, the pair of chains of the main chain conveyor 4 meshes with two pairs of pinions 9, 10, which have the same diameter and are arranged so that their axes lie on a same horizontal plane, so that the main chain conveyor 4 has exclusively an advancement branch 7, or upper branch, which is horizontal, and a return branch 8, or lower branch, which also is horizontal and is arranged below and parallel to the advancement branch 7.
The secondary chain conveyor 5 is composed of a pair of side-by-side chains and is extended along a closed path that is laterally superimposed on the path of the main chain conveyor 4 at least proximate to the ends of the advancement branch 7 of the main chain conveyor 4.
The storage chain conveyor 6 also is composed of a pair of side-by-side chains and is extended along a closed path.
The machine according to the invention comprises a plurality of conveyor rollers 11, which support the fabric 12 inside the treatment chamber 3 and can engage the chain conveyors 4, 5, 6.
More particularly, the chain conveyors 4, 5, 6 are provided with pairs of supports 43, 44, 45 that can be engaged detachably by end regions of the conveyor rollers 11. Each pair of supports 43, 44, 45 is composed of two supports, which are mutually aligned at right angles to the extension of the corresponding chain conveyor 4, 5, 6.
The machine according to the invention comprises means 13 for feeding the fabric 12 to be treated to conveyor rollers 11 arranged on the secondary chain conveyor 5. The feeder means 13 are arranged proximate to a first end of the advancement branch 7 of the main chain conveyor 4.
The machine according to the invention comprises means 14 for removing the treated fabric 12, which are arranged proximate to a second end, which is opposite with respect to the first end, of the advancement branch 7 of the main chain conveyor 4.
The machine according to the invention also comprises means 15 for transferring the conveyor rollers 11 from the secondary chain conveyor 5 to the storage chain conveyor 6 and vice versa.
According to the invention, the storage chain conveyor 6 is arranged below at least the advancement branch 7 of the main chain conveyor 4.
Preferably, the pair of chains of the storage chain conveyor 6, in a manner similar to the main chain conveyor 4, meshes with two pairs of pinions 16, 17 that have the same diameter and are arranged so that their axes lie on a same horizontal plane, so that the storage chain conveyor 6 exclusively has a horizontal upper branch 18 and a lower branch 19 which also is horizontal and is arranged below and parallel to the upper branch 18.
Conveniently, the storage chain conveyor 6 is substantially aligned vertically with the main chain conveyor 4 so that the presence of the storage chain conveyor 6 practically requires no increase in the plan dimensions of the machine.
The feeder means 13 comprise a belt conveyor 20 which winds, along a closed path, on a set of three rollers 21, 22, 23 and is contacted by a tension roller 24. The rollers 21, 22, 23, 24 are arranged so that their axes are parallel to the axes of the pinions of the chain conveyors 4, 5, 6 at an inlet opening 25 defined in the front wall 26 of the treatment chamber 3.
The removal means 14 comprise a set of three rollers 27, 28, 29, two of which are arranged again within the treatment chamber 3 and one of which is arranged outside the treatment chamber 3 so as to define a portion of a path for the fabric 12 that passes through an exit opening 30 defined in the rear wall 31, which lies opposite the front wall 26, of the box-like enclosure 2, in order to extract and remove the fabric 12 from the treatment chamber 3. The rollers 27, 28, 29 are arranged so that their axes are parallel to the axes of the pinions of the chain conveyors 4, 5, 6.
The pair of chains of the secondary chain conveyor 5 meshes with pairs of pinions 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, which define, for the secondary chain conveyor 5, a closed path which is extended from a region that is proximate to the inlet opening 25 of the treatment chamber 3, laterally superimposed on the main chain conveyor 4, below it, and then again laterally superimposed on said main chain conveyor 4, above the main chain conveyor 4, then above the storage chain conveyor 6, to then return again proximate to the inlet opening 25 of the treatment chamber 3.
Preferably, a lower branch 42 of the secondary chain conveyor 5 is arranged horizontally and faces in an upper region, for at least one portion, the upper branch 18 of the storage chain conveyor 6.
The supports 43 for the conveyor rollers 11 of the main chain conveyor 4 are dovetail-shaped and are fixed to the links of the chains of the main chain conveyor 4. Each one of the supports 43 defines a receptacle that can be engaged detachably by an end region of a conveyor roller 11. The pairs of supports 43 are uniformly mutually spaced along the extension of the main chain conveyor 4 so that the center distance between two conveyor rollers 11 engaged with two contiguous pairs of supports 43 of the main chain conveyor 4 corresponds to the center distance required for a correct steaming of the fabric 12, usually equal to 101 mm.
The supports 44 for the conveyor rollers 11 of the secondary chain conveyor 5 also are dovetail-shaped, so that each one defines a receptacle that can be engaged detachably by an end region of a conveyor roller 11, but are connected to the links of the chains of the secondary chain conveyor 5 so that they can each oscillate about a corresponding horizontal axis so as to keep the opening of the receptacle for the end regions of the corresponding conveyor roller 11 constantly directed upward regardless of their position along the path of the secondary chain conveyor 5, in order to support adequately the corresponding conveyor roller 11.
The supports 45 for the conveyor rollers 11 of the storage chain conveyor 6 are dovetail-shaped, so that each one defines a receptacle that can be engaged detachably by an end region of a conveyor roller 11, and are fixed to the links of the chain of the storage chain conveyor 6. As shown, these supports can occupy only part of the extension of the storage chain conveyor 6.
Conveniently, the supports 44 for the conveyor rollers 11 of the secondary chain conveyor 5 engage end regions of the conveyor rollers 11 that are located outside the regions with which the supports 43, 45 of the main chain conveyor 4 and of the storage chain conveyor 6 engage and the two vertical planes along which the chains of the secondary chain conveyor 5 are extended are located outside the vertical planes in which the chains of the main chain conveyor 4 and of the storage chain conveyor 6 are extended.
The transfer means 15 comprise a pair of levers 46, which are mutually aligned parallel to the axes of the pinions of the chain conveyors 4, 5, 6, each of which supports a corresponding support 47 that can be engaged in each instance with two mutually axially spaced regions of one of the conveyor rollers 11 so as to lift it, with consequent disengagement from a pair of supports 45, 44 arranged on the upper branch 18 of the storage chain conveyor 6 or on the lower branch 42 of the secondary chain conveyor 5 that faces it in an upward region, and its lowering with consequent release onto a pair of supports 45, 44 arranged on the upper branch 18 of the storage chain conveyor 6 or on the lower branch 42 of the secondary chain conveyor 5 that faces it in an upward region.
The supports 47 connected to the pair of levers 46 also are dovetail-shaped, in a manner similar to the supports 43 that are fixed to the links of the chains of the main chain conveyor 4, so as to define a receptacle that is open upward and can be engaged by end regions of a conveyor roller 11.
Preferably, the pair of levers 46 is connected to a slot-link mechanism 48, which can be actuated in order to lift the pair of levers 46 synchronously with the advancement of the storage chain conveyor 6 and of the secondary chain conveyor 5. Although a single slot-link mechanism 48 that actuates the pair of levers 46 can be used, in the illustrated embodiment there are two slot-link mechanisms 48, one for each lever of the pair of levers 46, in which the corresponding cranks 49 are actuated with a rotary motion integrally with each other. More particularly, each lever of the pair of levers 46 constitutes the slider of a slot-link mechanism 48 that is composed of a crank 49 and a slot-link or oscillating rod 50 actuated by the rotation of the crank 49.
Operation of the machine according to the invention is as follows.
The fabric 12 is introduced in the treatment chamber 3 by the belt conveyor 20, the advancement of which causes the forming of a loop of fabric 12 that descends. The forming of the loop is interrupted when it is contacted by the arrival of a conveyor roller 11 supported by the secondary chain conveyor 5. The loop of fabric 12 is conveyed toward the main chain conveyor 4 while the belt conveyor 20 begins the forming of a new loop of fabric 12. The conveyor roller 11 that supports the loop of fabric 12, due to the fact that the secondary chain conveyor 5, proximate to the first end of the advancement branch 7 of the main chain conveyor 4, descends below the upper branch 7 of the main chain conveyor 4, engages a pair of supports 43 of the main chain conveyor 4, disengaging from the pair of supports 44 of the secondary chain conveyor 4 that supported it previously. Due to the fact that the actuation of the secondary chain conveyor 5 is synchronized with the actuation of the main chain conveyor 4, while the subsequent conveyor roller 11, after receiving a new loop of fabric 12, arrives proximate to the first end of the advancement branch 7 of the main chain conveyor 4, at the point of arrival of the secondary chain conveyor 5 there is the pair of supports 43 that follows the one that received the previous conveyor roller 11. In this manner, the new conveyor roller 11 with the new loop of fabric 12 engages the pair of supports 43 of the main chain conveyor 4, leaving the secondary chain conveyor 5.
This sequence continues until all the pairs of supports 43 of the main chain conveyor 4 arranged on the upper branch 7 are occupied with conveyor rollers 11 that support the corresponding loops of fabric 12, as shown in Figure 1. The advancement speed of the main chain conveyor 4 is such that the time required to move a conveyor roller 11 from the end of the advancement branch 7 of the main chain conveyor 4 located proximate to the inlet opening 25 of the treatment chamber 3 to the end of the advancement branch 7 of the main chain conveyor 4 located proximate to the exit opening 30 of the treatment chamber 3 corresponds to the time required to obtain the correct steaming treatment. Proximate to the exit opening 30 of the treatment chamber 3, the fabric 12 passes over the rollers 27, 28, 29 and is extracted and removed from the treatment chamber 3. The conveyor rollers 11, freed from the fabric 12, are picked up by the pairs of supports 44 of the secondary chain conveyor 5, which, proximate to the end of the advancement branch 7 located proximate to the exit opening 30, returns above the advancement branch 7of the main chain conveyor 4.
When a greater spacing of the loops of fabric 12 is required during treatment, i.e., a reduction of the number of conveyor rollers 11 along the main chain conveyor 4 is required, one proceeds by halving the number of conveyor rollers 11 used, so that the main chain conveyor 4 supports one conveyor roller 11 for every two contiguous pairs of supports 43. This reduction of the number of conveyor rollers 11 in use is obtained by transferring in each instance a conveyor roller 11 from the secondary chain conveyor 5 to the storage chain conveyor 6.
This transfer is performed by actuating the slot-link mechanisms 48, as shown in the sequence illustrated in Figures 4a to 4e. In greater detail, when the conveyor roller 11 to be transferred is arranged, supported by the corresponding pair of supports 44 of the secondary chain conveyor 5, above and in alignment with a pair of supports 45 of the storage chain conveyor 6 arranged in the upper branch 18 of the conveyor 6, as shown in Figure 4a, the slot-link mechanisms 48 are actuated so as to lift the pair of levers 46, which engages, by means of the corresponding pair of supports 47, two mutually axially spaced regions of the conveyor roller 11, lifting it and therefore disengaging it from the pair of supports 44 of the secondary chain conveyor 5, as shown in Figure 4b. Then, as shown in Figure 4c, the secondary chain conveyor 5 is made to advance so that the pair of its supports 44 that previously supported the conveyor roller 11 now engaged by the pair of levers 46 cannot interfere with the conveyor roller 11 during its descent. At this point the slot-link mechanisms 48 lower the pair of levers 46, which deposit the conveyor roller 11 on the pair of supports 45 of the underlying storage chain conveyor 6, as shown in Figure 4d. The pair of supports 47 of the pair of levers 46 continues its descent below the pair of supports 44 of the secondary chain conveyor 5, so as to disengage completely from the conveyor roller 11, and the storage chain conveyor 6 is made to advance by one step so as to bring a subsequent pair of supports 45 into alignment with a pair of supports 44 of the secondary chain conveyor 5, which in the meantime has arrived, as a consequence of the advancement of the secondary chain conveyor 5, at the pair of supports 47 supported by the pair of levers 46, as shown in Figure 4e. It should be noted that the transfer of a conveyor roller 11 from the secondary chain conveyor 5 to the storage chain conveyor 6 is performed every two contiguous conveyor rollers 11 supported by the secondary chain conveyor 5, so that for every two conveyor rollers 11 of the secondary chain conveyor 5 one is transferred to the storage chain conveyor 6, while the directly subsequent or preceding one remains on the secondary chain conveyor 5 and continues its advancement in order to encounter the loop of fabric 12 that it will have to support. At this point the transfer sequence of a conveyor roller 11 from the secondary chain conveyor 5 to the storage chain conveyor 6 is repeated as already described until the desired quantity of conveyor rollers 11, which is usually equal to half the number of conveyor rollers 11 with which the machine is equipped, is transferred from the secondary chain conveyor 5 to the storage chain conveyor 6, as shown in Figure 7.
In this manner, the main chain conveyor 4 carries one conveyor roller 11 for every two contiguous pairs of supports 43 and therefore the loops of fabric 12 are further mutually spaced during the steaming treatment.
Obviously, if a greater spacing between the loops of fabric 12 is required, it is possible to transfer a larger number of conveyor rollers 11 from the secondary chain conveyor 5 to the storage chain conveyor 6, providing an adequate number of pairs of supports 45 on the storage chain conveyor 6.
When use of all the conveyor rollers 11 that can be potentially carried by the main chain conveyor 4 is required, one proceeds in reverse to what has been described, i.e., in each instance a conveyor roller 11 is transferred from the storage chain conveyor 6 to the secondary chain conveyor 5, as shown in particular in Figures 5a to 5e.
More particularly, with a pair of supports 45 of the storage chain conveyor 6 that supports a corresponding conveyor roller 11, arranged at the pair of supports 47 supported by the pair of levers 46 so that the corresponding conveyor roller 11 lies above the pair of supports 47 of the pair of levers 46, as shown in Figure 5a, the slot-link mechanisms 48 are actuated and lift the pair of levers 46. In this manner, the pair of supports 47 supported by the pair of levers 46 engages two mutually axially spaced regions of the conveyor roller 11, lifting it and therefore disengaging it from the pair of supports 45 of the storage chain conveyor 6, as shown in Figure 5b. It should be noted that the lifting of the pair of levers 46 is performed while at such pair of levers 46 there is no pair of supports 44 of the secondary chain conveyor 5, so as to avoid interference between the pairs of supports 44 supported by the secondary chain conveyor 5 with the conveyor roller 11 lifted.
The advancement of the secondary chain conveyor 5 therefore brings a pair of supports 44 at the pair of supports 47 of the pair of levers 46, below the conveyor roller 11 that is still supported by the pair of levers 46, as shown in Figure 5c. At this point the slot-link mechanisms 48 lower the pair of levers 46, which in this manner releases the conveyor roller 11 onto the pair of supports 44 of the secondary chain conveyor 5, as shown in Figure 5d.
Then, the secondary chain conveyor 5 is made to advance, and likewise the storage chain conveyor 6 is made to advance by one step and positions a new conveyor roller 11 at the pair of supports 47 of the pair of levers 46, as shown in Figure 5e, in a position that is suitable for the subsequent transfer from the storage chain conveyor 6 to the secondary chain conveyor 5, which occurs as already described.
The transfer of conveyor rollers 11 from the storage chain conveyor 6 to the secondary chain conveyor 5 continues as already described until a number of conveyor rollers 11 equal to that required to utilize the maximum supporting capacity of conveyor rollers 11 by the main chain conveyor 4 is transferred.
It should be noted that the actuation of the secondary chain conveyor 5, of the storage chain conveyor 6 and of the slot-link mechanisms 48 is actuated and controlled by way of electronic control means of the known type, which ensure the correct placement of a pair of supports 44 of the secondary chain conveyor 5 and of a pair of supports 45 of the storage chain conveyor 6 at the pair of supports 47 of the pair of levers 46 that must transfer a conveyor roller 11 from the secondary chain conveyor 5 to the storage chain conveyor 6 or vice versa. The actuation of the secondary chain conveyor 5, further, is correlated with the actuation of the main chain conveyor 4 so as to ensure the correct passage, in each instance, of a conveyor roller 11 from the secondary chain conveyor 5 to the main chain conveyor 4 and vice versa and allow the forming of loops of fabric 12, supported by the conveyor rollers 11, of the desired length.
In practice it has been found that the machine according to the invention achieves fully the intended aim, since it is able to operate both at its maximum production potential, utilizing all the conveyor rollers that the main chain conveyor can carry, and with a reduced production potential, in particular by using only half of the conveyor rollers that the main chain conveyor can carry in order to double the distance between the loops of fabric during the steaming treatment despite having a plan space occupation that is substantially unchanged with respect to machines of the known type that do not offer this possibility.
A further advantage of the machine according to the invention is that it is provided with a storage chain conveyor that can be kept in operation even when it is not used, without interfering with the overall operation of the machine. In this manner high reliability in operation is maintained, reducing the number of maintenance interventions required.
The machine thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; furthermore, all the details may be replaced with other technically equivalent elements.
In practice, the materials used, as well as the dimensions, may be any according to requirements and to the state of the art.
The disclosures in Italian Patent Application No. 102015000015741 ( UB2015A000844 ) from which this application claims priority are incorporated herein by reference.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

A machine for steaming fabrics, comprising a box-like enclosure (2) that defines inside it a treatment chamber (3) that accommodates:
- a main chain conveyor (4), composed of a pair of side-by-side chains and extended along a closed path that has a substantially horizontal advancement branch (7) arranged in an upper region of said treatment chamber (3);

- a secondary chain conveyor (5), composed of a pair of side-by-side chains and extended along a closed path that is superimposed laterally on the path of said main chain conveyor (4) at least proximate to the ends of said advancement branch (7);

- a storage chain conveyor (6), composed of a pair of side-by-side chains and extended along a closed path;

- a plurality of rollers (11) for conveying the fabric (12);
said chain conveyors (4, 5, 6) being provided with pairs of supports (43, 44, 45) that can be engaged detachably by end regions of said conveyor rollers (11);
there being provided:
- means (13) for feeding the fabric (12) to be treated to conveyor rollers (11) arranged on said secondary chain conveyor (5), said feeder means (13) being located proximate to a first end of said advancement branch (7) of the main chain conveyor (4);

- means (14) for removing the treated fabric (12), which are arranged proximate to a second end, opposite said first end, of said advancement branch (7) of the main chain conveyor (4);

- means (15) for transferring said conveyor rollers (11) from said secondary chain conveyor (5) to said storage chain conveyor (6) and vice versa;
characterized in that said storage chain conveyor (6) is arranged below said advancement branch (7) of said main chain conveyor (4).
The machine according to claim 1, characterized in that said main chain conveyor (4) is composed of said advancement branch (7) and of a return branch (8) that is arranged below said advancement branch (7) and parallel thereto.
The machine according to claims 1 and 2, characterized in that said storage chain conveyor (6) comprises a lower branch (19), which is substantially horizontal, and an upper branch (18), which is substantially horizontal and is superimposed on said lower branch (19).
The machine according to one or more of the preceding claims, characterized in that said storage chain conveyor (6) is substantially aligned vertically with said main chain conveyor (4).
The machine according to one or more of the preceding claims, characterized in that said secondary chain conveyor (5) has a substantially horizontal lower branch (42) that faces in an upper region the upper branch (18) of said storage chain conveyor (6).
The machine according to one or more of the preceding claims, characterized in that said transfer means (15) are adapted to transfer said conveyor rollers (11) from said lower branch (42) of the secondary chain conveyor (5) to said upper branch (18) of the storage chain conveyor (6) and vice versa.
The machine according to one or more of the preceding claims, characterized in that the supports of said pairs of supports (43, 44, 45) of said chain conveyors (4, 5, 6) are dovetail-shaped in order to define a receptacle that can be engaged by an end region of said conveyor rollers (11).
The machine according to one or more of the preceding claims, characterized in that the supports (44) connected to the chains of said secondary chain conveyor (5) can each oscillate about a corresponding horizontal axis in order to maintain the opening of the corresponding receptacle directed upward regardless of their position along the path of said secondary chain conveyor (5).
The machine according to one or more of the preceding claims, characterized in that the chains of each one of said chain conveyors (4, 5, 6) are each extended on a corresponding vertical plane, the two vertical planes on which the chains of said secondary chain conveyor (5) are extended being arranged externally to the vertical planes along which the chains of said main chain conveyor (4) and of said storage chain conveyor (6) are extended.
The machine according to one or more of the preceding claims, characterized in that said transfer means (15) comprise a pair of levers (46) that support a pair of supports (47) that can engage in each instance two mutually axially spaced regions of one of said conveyor rollers (11) in order to lift it, with consequent disengagement, from a pair of supports (45) arranged on the upper branch (18) of said storage chain conveyor (6) and lower it, with consequent release, onto a pair of supports (44) arranged on the lower branch (42) of said secondary chain conveyor (5) or vice versa.
The machine according to one or more of the preceding claims, characterized in that the supports of said pair of supports (47) of said pair of levers (46) are dovetail-shaped in order to define a receptacle that is open upward and can be engaged with two mutually axially spaced regions of a conveyor roller (11).
The machine according to one or more of the preceding claims, characterized in that said pair of levers (46) is connected to at least one slot-link mechanism (48) that can be operated in order to lift said pair of levers (46) in a manner that is synchronized with the advancement of said storage chain conveyor (6) and of said secondary chain conveyor (5).