Suction cutting conveyor for an automatic blade cutting machine for laminated materials

Abstract

The invention relates to a suction cutting conveyor of an automatic blade cutting machine for laminated materials, comprising a plurality of cutting supports (14) rigidly connected to a drive mechanism driven along straight and curvilinear paths, each cutting support comprising a plurality of bristles (16) each having a leg (16a) rigidly connected to a base (18) and a head (16b) opposite the leg and on which a laminated material to be cut is intended to rest, the base of each cutting support being capable of elastic deformation following the paths of the drive mechanism.

Description

SUCTION CUTTING CONVEYOR FOR AN AUTOMATIC BLADE CUTTING MACHINE FOR LAMINATED MATERIALS Field of invention The present invention relates to a suction conveyor for an automatic machine for cutting laminated materials, in particular textile materials, by means of a vibrating blade that penetrates the cutting support. State of the art One field of application of the invention is the automatic cutting of stacks or mats of sheets of material, in particular textile material, by means of a vibrating blade that penetrates a cutting support by suction. Typically, a vibrating blade cutting machine includes a cutting conveyor that propels the stack of sheets during the cutting operation. This cutting conveyor is housed in a casing where a strong vacuum is created to keep the sheets of material immobile during the cutting process. In this type of machine, the cutting conveyor also serves as a penetrating cutting support for the vibrating blade. In fact, it is well known to make the cutting support penetrable by the blade so that, during the cutting operation, the blade can not only completely penetrate the material being cut, but also extend downwards beyond the support surface and into the material bed that supplies that surface. To this end, as shown schematically in Figure 1, the conveyor 1 generally comprises a plurality of cutting supports 2, each of which is rigidly connected to a belt 3 of a drive conveyor. This conveyor also comprises, at each end of the table, a gear 5 centered on a horizontal axis 4 and driving the belt 3 along straight and curved paths. Furthermore, each cutting support 2 comprises a plurality of bristles 6 mounted on a base 7 forming several parallel rows of bristles, each bristle having a head that forms the support for the sheet material to be cut. The passages cut through the base allow the suction air to pass through. These cutting supports thus allow the material to be held under vacuum while allowing it to be penetrated by the cutting blade. However, this type of assembly has a considerable disadvantage during the rotation of the conveyor at the end of the table. In fact, as shown in Figure 1, during the rotation of the cutting supports at the end of the table (to reverse their direction), they wind around the gear 5 and tend to spread apart (i.e., separate from each other). frAQC ίΠ / ΖΖηΖ / Ε / ΥΙΛΙ On one hand, the rotation of the cutting supports forces the material discharge tabs 8 at the end of the cutting surface to be positioned at a height h above the cutting surface. However, this height difference is detrimental to the user of the cutting machine because, as the cutting mat M passes over it, the material can be deformed by stretching and thus impact the cut pieces at this end. Alternatively, during the loading of the mat (opposite the discharge side), the material is stretched and then compressed during the vacuum application phase, creating stresses in the material that would degrade the quality of the cut pieces. On the other hand, the material discharge tabs 8 must be positioned vertically offset from the horizontal axes 4, driving the conveyor's gears 5 to prevent an opening between the cutting supports. This opening creates a gap at the bristle head where material can fall out if the combs do not prevent it. This constraint requires long combs held in a vacuum and their dimensions to be determined accordingly. Depending on the width of the cutting supports, the distance between the drive and the cutting support heads, and the connection between the supports and the drive, the effective cutting length may be reduced to avoid this area. Disclosure of the invention The invention therefore aims to propose a cutting support that does not present the disadvantages mentioned above. This object is achieved by means of a suction cutting conveyor of an automatic blade cutting machine for sheet material, comprising a plurality of cutting supports rigidly connected to a drive mechanism driven along straight and curvilinear paths, each cutting support comprising a plurality of bristles, each of which has a leg rigidly attached to a base and a head opposite the leg and on which a sheet material to be cut is intended to rest, wherein, in accordance with the invention, the base of each cutting support is capable of being elastically deformed following the paths of the drive mechanism. What is meant here by being able to deform elastically is that the base of the shear supports has intrinsic characteristics that give it a deformation property in the elastic range, that is, a reversible deformation without yielding whereby the base, when released from the stresses, returns to its original shape. The invention is noteworthy in that each of the cutting supports has a base with a degree of flex in the transverse direction, allowing them to deform to follow the paths of the drive mechanism, particularly during the rotation of the conveyor at the front and rear ends of the table to reverse direction. The invention is also noteworthy in that the plane of the drive mechanism of the cutting supports is located in the plane of the base of the cutting supports. This reduces the space between the cutting supports, allowing for a larger cutting surface with the same conveyor dimensions. Furthermore, the cutting supports—and more specifically their bases—deform but do not rotate, enabling the combs or rakes to be lowered at the front and rear ends of the cutting surface. This prevents the material from stretching and causing all the associated problems. The base of each cutting support may have a plurality of parallel geometric shapes extending in directions perpendicular to the drive mechanism's travel direction to allow elastic deformation following the drive mechanism's paths. These shapes enable the base to be flexible while maintaining the bristles perpendicular to the tangent to this base, even during operation. In this case, the geometric shapes of the base of the cutting supports may consist of a plurality of parallel grooves. The grooves of the base may comprise external grooves projecting outward from an outer surface of the base and / or internal grooves projecting inward from an inner surface of the base. The grooves of the base may comprise an alternating pattern of external and internal grooves to give an accordion shape. The grooves may have a rectangular, square, or rounded cross-section. The base of each cutting support can be made of plastic material, and this material must be compatible with the deformations induced during operation. Each of the cutting supports can be mounted by its respective base on a transmission element of the drive mechanism by means of at least one clamping rail. In this case, each cutting support can be mounted on the drive mechanism's transmission element by means of at least two longitudinally spaced clamping rails. At least one of the two clamping rails can be used with two adjacent cutting supports. Preferably, the conveyor also includes an air cleaning device for the cutting supports. The air cleaning device may include an air blow nozzle and a dust collector. The invention also relates to an automatic blade cutting machine for laminated materials, comprising a conveyor as defined above. Brief description of the drawings [Figure 1] Figure 1 (already described) is seen schematically from one end of the state art cutting table. [Figure 2] Figure 2 shows one end of the suction cutting conveyor equipped with a plurality of cutting supports according to an embodiment of the invention. [Figure 3] Figure 3 is an enlargement of Figure 2 that shows more accurately the cutting supports of Figure 2 on the discharge tabs of the cutting surface. [Figure 4] Figure 4 is an enlargement of Figure 3 that shows more accurately the shape of the base of the cutting supports in Figure 2. [Figure 5] Figure 5 shows in perspective and partially the base of the cutting supports of Figure 2. [Figure 6] Figure 6 schematically shows the deformation of a base of a cutting support according to a variant of the embodiment of the invention. Description of the modalities The present invention relates to cutting supports for a suction cutting conveyor of an automatic blade cutting machine for laminated materials, such as conveyor 10 shown partially in Figure 2. A cutting conveyor of this type, 10, is commonly used to propel the stack of sheets during the cutting operation. This cutting conveyor is typically housed in a box 12 within which a strong vacuum is created to keep the sheets of material to be cut stationary during the cutting operation. Furthermore, the cutting conveyor also served as a penetrating cutting support for the vibrating blade. In fact, it is well known to make the cutting support penetrable by the blade so that, during the cutting operation, the blade can not only fully penetrate the material being cut, but also extend downwards beyond the support surface and into the material bed provided by that surface. The cutting conveyor 10 generally comprises a plurality of cutting supports 14. Each cutting support comprises a plurality of bristles 16, each of which has a leg 16a mounted on a base 18 forming several parallel rows of bristles, and a head 16b opposite the leg and on which the sheet material to be cut is intended to rest (see figure 3). The cutting supports 14 are mounted by means of their respective bases on a transmission belt 20 driven at each end of the table by toothed wheels 24 centered on horizontal axes 22. The transmission belt 20 is thus driven in a straight line (between the two ends of the cutting table), and curved paths (at each end of the cutting table, to reverse the direction). Of course, the drive belt could be replaced by a chain, a toothed belt, or any other transmission mechanism. In addition, transverse channels 25 are known to be provided through the bases of the frRQC ίΠ / ZZΖηZ / E / YΙΛΙ cutting supports to allow suction air to pass through the bases (Figure 4). The cutting supports thus allow the material to be cut to be held under vacuum while still being penetrated by the cutting blade. They define the cutting surface S of the cutting machine. Furthermore, at the longitudinal end of the cutting surface S (with respect to the direction of travel T of the cutting conveyor), the cutting table comprises a plurality of discharge tabs 26 generally raised with respect to the cutting surface (see the prior art in Figure 1). These discharge tabs 26 extend across the entire width of the cutting surface and thus assist in the discharge of material away from the cutting surface. Likewise, at the longitudinal end opposite the cutting surface S, the cutting table also comprises a plurality of loading tabs (not shown in the figures) which are generally raised with respect to the cutting surface and which help in loading the material onto the cutting surface. According to the invention, the base 18 on which the bristles 16 of the different cutting supports are mounted is capable of being elastically deformed following the paths of the transmission belt 20. What is meant here by being able to deform elastically is that the base of the cutting supports has intrinsic characteristics that give it an elastic deformation property. Several methods can be considered to achieve this intrinsic property of the bases of the cutting supports. Thus, in the modality of figures 3 to 5, the base 18 of each cutting support has a plurality of parallel geometric shapes that extend in directions perpendicular to the direction of advance of the transmission belt to allow elastic deformation following the paths of the transmission belt. More precisely, the geometric shapes of the base of the cutting supports consist here of a plurality of parallel grooves (or folds) that extend in a transverse direction (i.e., they extend in a direction perpendicular to the feed direction T of the cutting conveyor). Even more precisely, the slots consist of external slots 28a that protrude outwards from the base and internal slots 28b that protrude inwards from the support. In this modality, as shown in figures 4 and 5, the grooves 28a, 28b are arranged alternately to give the base an accordion shape, giving it the property of plastic deformation. The presence of accordion-shaped grooves 28a, 28b allows the base of the cutting support according to the invention to deform elastically when bent in the forward direction T of the cutting conveyor. frAQC ίη / 77Ω7 / Β / YΙΛΙ In this configuration, the slots have a rectangular cross-section. This cross-section could alternatively be square or rounded. Likewise, the slots in the base could be present only on one of the two sides of the base (i.e., protruding only outwards or inwards from the base). In this configuration, elastic deformation is possible due to the particular shape of the base. This allows, on the one hand, for an excessively large gap between adjacent cutting supports to be avoided and, on the other hand, for limiting or reducing to zero the lifting height of the discharge tabs 26 with respect to the cutting surface S. In another embodiment of the invention shown in particular in Figure 6, the base 18' of the cutting supports has intrinsic characteristics that give it an elastic deformation property due to its composition. In fact, in this modality, the base 18' is made of a plastic material capable of allowing elastic deformation following the trajectories of the drive mechanism (in figure 6, the base 18' is in a deformed state). For example, a plastic material can be selected, for example, from the families of polyamides or polypropylenes. More precisely, Figure 6 shows a modular element 36 for cutting support as described in detail in patent application FR 20 / 03043, filed on March 27, 2020 by the applicant. This modular element 36 comprises a plurality of bristles 16' arranged according to the same identical line and whose respective legs are rigidly connected to a base 18' of plastic material capable of allowing elastic deformation. In this modality, the 18' base is provided with a plurality of transverse channels 25' for the passage of air by suction. In another modality (not shown in the figures), the base and bristles of a cutting support are made of different materials (particularly plastic). The following will describe different characteristics of the cutting support, regardless of its type. In particular, different configurations are possible for mounting cutting supports according to the invention on the transmission belt 20. In the configuration shown in Figures 2 and 3, each cutting support 14 is mounted on the transmission belt 20 by means of two clamping rails 30 separated longitudinally from each other. Of course, other configurations are possible. For example, in another arrangement (not shown in the figures), each cutting support can be mounted on the drive belt using three longitudinally spaced clamping rails. In yet another configuration, each cutting support is mounted on the drive belt by means of three clamping rails; one fixing rail mounted only on the rail, and two other clamping rails mounted commonly on the cutting support and on the two adjacent cutting supports 5. According to an advantageous arrangement of the invention illustrated in Figure 2, the cutting conveyor 10 may further comprise a device for cleaning the cutting supports 14 using air. This cleaning device comprises, in particular, an air blower nozzle 32 mounted on the horizontal shaft 22 of one of the gears 24 and extending along its radius 10. As the drive belt rotates around the horizontal shaft 22, the nozzle 32 presses against the outer face of the base of the cutting supports and blows air through it to dislodge dust and impurities lodged at the bottom of the base. A collector 34 positioned in front of the cutting support on the bristle head side allows the dislodged dust to be collected. It will be observed that the invention applies equally well to cutting conveyors that use 15 loading and unloading tabs as to those that use loading and unloading rakes instead.

Claims

1. A suction cutting conveyor (10) of an automatic blade cutting machine for sheet material, comprising a plurality of cutting supports (14, 14') rigidly connected to a drive mechanism driven along straight and curvilinear paths, each cutting support comprising a plurality of bristles (16; 16') each of which has a leg (16a) rigidly connected to a base (18; 18') and a head (16b) opposite the leg and on which a sheet material to be cut is intended to rest, characterized in that the base of each cutting support is capable of being elastically deformed following the paths of the drive mechanism.

2. The conveyor according to claim 1, wherein the base (18) of each cutting support has a plurality of parallel geometric shapes extending in directions perpendicular to the forward direction of the drive mechanism to allow elastic deformation following the paths of the drive mechanism.

3. The conveyor according to claim 2, wherein the geometric shapes of the base of the cutting supports consist of a plurality of parallel grooves (28a, 28b).

4. The conveyor according to claim 3, wherein the base grooves comprise external grooves (28a) projecting outwards from an outer surface of the base and / or internal grooves (28b) projecting inwards from an inner surface of the base.

5. The conveyor according to claim 4, wherein the base slots comprise an alternation of external slots (28a) and internal slots to give the shape of an accordion.

6. The conveyor according to any of claims 3 to 5, wherein the slots have a rectangular, square or rounded cross-section.

7. The conveyor according to any of claims 1 to 6, wherein the base (18) of each cutting support is made of plastic material.

8. The conveyor according to any of claims 1 to 7, wherein each of the cutting supports is mounted by its respective base on a transmission element of the drive mechanism by means of at least one clamping rail (30).

9. The conveyor according to claim 8, wherein each cutting support is mounted on the transmission element of the drive mechanism by means of at least two clamping rails (30), longitudinally separated from each other.

10. The conveyor according to claim 9, wherein at least one of the two clamping rails cooperates with two adjacent cutting supports. frAQC ίη / 77Ω7 / Β / YΙΛΙ 11. The conveyor according to any of claims 1 to 10, further comprising a device for cleaning the cutting supports by means of air.

12. The conveyor according to claim 11, wherein the air cleaning device comprises an air blow nozzle (32) and a dust collector (34). 5 13. An automatic blade cutting machine for laminated materials comprising a conveyor (10; 10') according to any of claims 1 to 12.

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