Suction cutting conveyor for automatic blade cutting machine for sheet material

Abstract

The present invention relates to a suction cutting conveyor for an automatic blade cutter for sheet material, comprising a plurality of cutting supports (14) rigidly connected to a drive mechanism that is driven along linear and curved tracks, each cutting support comprising a plurality of bristles (16) each having a foot (16a) rigidly connected to a sole (18) and a head (16b) located opposite the foot and intended to receive the sheet material to be cut, the sole of each cutting support being elastically deformable in accordance with the tracks of the drive mechanism.

Description

[Technical Field]

[0001] The present invention relates to a suction conveyor for an automatic cutting machine for sheet material, in particular textile material, with a vibrating blade penetrating into a cutting support. [Background technology]

[0002] One field of application of the invention is that of automatic cutting of materials, in particular stacks or mats of sheets of textile material, by means of an oscillating blade penetrating into a suction cutting support.

[0003] Typically, a cutting machine having an oscillating blade includes a cutting conveyor that serves, among other things, to drive the stack of sheets during the cutting operation, and is housed within a box within which a strong vacuum is established to hold the sheets of material being cut immobile during the cutting operation.

[0004] In machines of this type, the cutting conveyor also serves as a through-cutting support for the vibrating blade, and in fact it is known to allow the cutting support to be penetrated by the blade so that during the cutting operation the blade can not only pass completely through the material to be cut, but also extend downward past the support surface to the bed of material providing such a surface.

[0005] For this purpose, as shown diagrammatically in Figure 1, the conveyor 1 generally comprises a number of cutting supports 2, each rigidly connected to a drive conveyor belt 3. This conveyor further comprises, at each end of the table, a sprocket 5, centered on a horizontal axis 4, for driving the belt 3 along straight and curved tracks.

[0006] Furthermore, each cutting support 2 comprises a plurality of bristles 6, which are attached to a sole 7 forming several parallel rows of bristles, each bristling with a head forming a support for the sheet material to be cut. Passages cut through the sole allow the passage of suction air. These cutting supports can therefore accommodate the entry of a cutting blade while making it possible to support the material to be cut under vacuum.

[0007] However, this type of assembly has considerable drawbacks when the conveyor rotates at the end of the table: in fact, as shown in Figure 1, when the cutting supports rotate at the end of the table (to reverse direction), the cutting supports tend to wrap around the sprockets 5 and spread apart (i.e., move away from each other).

[0008] On the one hand, the pivoting of the cutting support forces the material discharge lead 8 at the end of the cutting surface to be located at a height h above the cutting surface. However, this difference in height is detrimental to the user of the cutting machine, since when the cutting mat M passes, the material is stretched and deformed, and can therefore collide with the cut piece at this end, or when the mat is loaded (opposite the discharge), the material is stretched and then compressed during the vacuum application phase, thus causing stresses in this material that can reduce the quality of the cut piece.

[0009] On the other hand, the material discharge lead 8 must be positioned vertically offset from the horizontal axis 4 for driving the conveyor sprocket 5 in order to avoid a gap zone between the cutting supports that forms a gap between the bristle heads into which material could fall if not prevented by the comb. This constraint necessitates having long combs exposed to the vacuum and sizing them accordingly. Depending on the width of the cutting supports, the distance between the drive and the cutting support head, and the connection between the supports and the drive, it will be appreciated that the useful cutting length will be reduced to avoid this region. Summary of the Invention

[0010] The present invention therefore aims to propose a cutting support that does not have the above-mentioned drawbacks.

[0011] This object is achieved by a suction cutting conveyor of an automatic blade cutting machine for sheet material according to the present invention, which comprises a plurality of cutting supports rigidly connected to a drive mechanism which is driven along linear and curved tracks, each cutting support comprising a plurality of bristles each having a foot rigidly connected to a sole and a head located opposite the foot and intended to rest on which the sheet material to be cut is placed, the sole of each cutting support being able to elastically deform according to the tracks of the drive mechanism.

[0012] Here, "elastically deformable" means that the sole of the cutting support has inherent properties that endow it with the property of deformation within the elastic range, i.e., reversible deformation without creep, in which the sole returns to its original shape when the stress is released.

[0013] The invention is notable in that each cutting support has a sole with a degree of transverse flexibility that allows the cutting support to deform to follow the trajectory of the drive mechanism during rotation of the conveyor, particularly at the upstream and downstream ends of the table for reversing direction, and further in that the plane of the drive mechanism of the cutting support lies in the plane of the sole of the cutting support.

[0014] In this way, the gap between the cutting supports is reduced, allowing for a further extension of the cutting surface with the same conveyor dimensions. Furthermore, since the cutting supports, and more specifically the respective soles, deform but do not pivot, it is possible to lower the combs or rakes at the upstream and downstream ends of the cutting surface. Therefore, deformation of the material due to stretching and all the problems that this causes can be avoided.

[0015] The sole of each cutting support may have a plurality of parallel geometric shapes extending along a direction perpendicular to the direction of travel of the drive mechanism to enable elastic deformation according to the trajectory of the drive mechanism, which shapes may enable the sole to be flexible yet still hold the bristles perpendicular to the tangent of the sole during operation.

[0016] In this case, the geometric shape of the sole of the cutting support can be composed of a plurality of parallel slots. The sole slots can be composed of external slots that protrude outward relative to the outer surface of the sole and / or internal slots that protrude inward relative to the inner surface of the sole. The sole slots can be composed of alternating external and internal slots that create an accordion shape. The slots can have a rectangular, square, or rounded cross section.

[0017] The sole of each cutting support can be made of a plastic material, which must be able to adapt to the deformations that occur during operation.

[0018] Each of the cutting supports can be attached by its respective sole to a transmission member of the drive mechanism by means of at least one fastening batten.

[0019] In this case, each cutting support can be attached to the transmission member of the drive mechanism by at least two fastening battens spaced apart from one another in the longitudinal direction, at least one of the two fastening battens being able to cooperate with two adjacent cutting supports.

[0020] Preferably, the cutting support further comprises a device for cleaning the cutting support with air. The air cleaning device may comprise an air nozzle and a dust collector.

[0021] Furthermore, the invention is directed to an automatic blade cutter for sheet material, comprising a conveyor as defined above. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 (already discussed) is a schematic diagram of one end of a prior art cutting table. [Figure 2] FIG. 2 shows one end of a vacuum cutting conveyor with multiple cutting supports according to one embodiment of the present invention. [Figure 3] FIG. 3 is an enlarged view of FIG. 2 showing more precisely the cutting support of FIG. 2 at the discharge lead of the cutting surface. [Figure 4] FIG. 4 is an enlarged view of FIG. 3 showing more precisely the shape of the sole of the cutting support of FIG. [Figure 5] FIG. 5 shows a perspective view of a portion of the sole of the cutting support of FIG. [Figure 6] FIG. 6 shows diagrammatically a deformation of the sole of a cutting support according to a variant embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention relates to a cutting support for a suction cutting conveyor of an automatic blade cutter for sheet material, such as conveyor 10, a portion of which is shown in FIG.

[0024] In known manner, a cutting conveyor 10 of this type serves to drive the stack of sheets in the cutting operation and is typically housed in a box 12 within which a strong vacuum is established to hold the sheets of material being cut immobile during the cutting operation.

[0025] Furthermore, the cutting conveyor also serves as a through-cutting support for the vibrating blade: in fact, it is known to allow the cutting support to be penetrated by the blade so that during the cutting operation the blade can not only pass completely through the material to be cut, but also extend downward past the support surface to the bed of material providing such a surface.

[0026] The cutting conveyor 10 generally comprises a plurality of cutting supports 14. Each cutting support comprises a plurality of bristles 16, each having a foot 16a attached to a sole 18 forming several parallel rows of bristles, and a head 16b opposite the foot and intended to receive the sheet material to be cut (see FIG. 3).

[0027] The cutting supports 14 are mounted by their respective soles on a drive belt 20 that is driven at each end of the table by a sprocket 24 about a horizontal axis 22. The drive belt 20 is therefore driven along a straight trajectory (between the two ends of the cutting table) and a curved trajectory (at each end of the cutting table for reversing direction).

[0028] Of course, the drive belt can be replaced by a chain, a toothed belt, or any other drive mechanism.

[0029] Furthermore, in a known manner, a transverse channel 25 is provided through the sole of the cutting support to allow suction air to pass through the sole (FIG. 4).

[0030] In this way, the cutting support allows the material to be cut to be supported under vacuum while still being able to accommodate the entry of the cutting blade. The cutting support defines the cutting plane S of the cutter.

[0031] Furthermore, at the longitudinal ends of the cutting surface S (relative to the direction of advancement T of the cutting conveyor), the cutting table is provided with a number of discharge leads 26 that are generally elevated relative to the cutting surface (see prior art FIG. 1 ), which extend over the entire width of the cutting surface and thus make it possible to assist in the discharge of material from the cutting surface.

[0032] Similarly, at the longitudinal end opposite the cutting surface S, the cutting table is generally elevated relative to the cutting surface and further comprises a plurality of loading leads (not shown) which allow for assisting in loading material onto the cutting surface.

[0033] According to the invention, the sole 18 to which the bristles 16 of the different cutting supports are attached may be able to deform elastically following the trajectory of the drive belt 20 .

[0034] Here, "elastically deformable" means that the sole of the cutting support has intrinsic properties that give it elastic deformability.

[0035] To reach this unique property of the sole of the cutting support, several embodiments are conceivable.

[0036] Thus, in the embodiment of Figures 3 to 5, the sole 18 of each cutting support has a plurality of parallel geometric shapes that extend along a direction perpendicular to the direction of travel of the drive belt and allow elastic deformation to follow the trajectory of the drive belt.

[0037] More precisely, the geometry of the sole of the cutting support here consists of a plurality of parallel slots (or folds) extending in the transverse direction (i.e. perpendicular to the direction of advance T of the cutting conveyor).

[0038] Even more precisely, the slot consists of an external slot 28a projecting outward from the sole and an internal slot 28b projecting towards the inside of the support.

[0039] In this embodiment, as shown in Figures 4 and 5, the slots 28a, 28b are arranged alternately to give the sole an accordion shape, imparting plastically deformable properties to the sole.

[0040] The presence of the accordion-shaped slots 28a, 28b allows the sole of the cutting support according to the invention to deform elastically when bending in the direction of advance T of the cutting conveyor.

[0041] In this embodiment, the slot has a rectangular cross section, which may alternatively be square or rounded.

[0042] Similarly, the slots in the sole may be present on only one of the two faces of the sole (ie, protruding only outward or inward from the sole).

[0043] In this embodiment, elastic deformation is possible due to the particular shape of the sole, which therefore makes it possible, on the one hand, to avoid excessively large gaps between adjacent cutting supports, and, on the other hand, to reduce the lift height of the ejection lead 26 relative to the cutting surface S, or even to reduce it to zero.

[0044] In another embodiment of the invention, particularly shown in FIG. 6, the sole 18' of the cutting support has inherent properties that give it elastic deformation properties due to its composition.

[0045] Indeed, in this embodiment, the sole 18' is made of a plastic material capable of allowing elastic deformation to follow the trajectory of the drive mechanism (in FIG. 6, the sole 18' is in a deformed state).

[0046] For example, the plastic material may be selected from the family of, for example, polyamide or polypropylene.

[0047] More precisely, Figure 6 shows a modular element 36 for a cutting support, which is described in detail in French patent application No. 20 / 03043, filed on March 27, 2020 by the applicant of the present application.

[0048] This modular element 36 comprises a number of bristles 16' arranged along the same line, the foot of each of which is firmly connected to a sole 18' made of a plastic material capable of allowing elastic deformation.

[0049] In this embodiment, the sole 18' includes a plurality of transverse channels 25' for passing suction air.

[0050] In another embodiment (not shown), the sole of the cutting support and the bristles are made of different (in particular plastic) materials.

[0051] Next, various features of the cutting support will be described, regardless of its embodiment.

[0052] In particular, various configurations are possible with regard to the assembly of the cutting support according to the invention onto the drive belt 20.

[0053] In the embodiment shown in Figures 2 and 3, each cutting support 14 is mounted on the drive belt 20 by two fastening battens 30 spaced longitudinally from one another.

[0054] Of course, other configurations are possible, for example, in another embodiment (not shown), each cutting support can be mounted on the drive belt by three fastening battens spaced longitudinally from one another.

[0055] In yet another embodiment, each cutting support is mounted on the drive belt by three fastening battens, namely one fastening batten attached only to the batten and two other fastening battens attached in common to the cutting support and two adjacent cutting supports.

[0056] According to an advantageous configuration of the invention shown in FIG. 2, the cutting conveyor 10 can further comprise a device for cleaning the cutting support 14 with air.

[0057] This cleaning device in particular comprises an air nozzle 32 attached to the horizontal axis 22 of one of the sprockets 24 and extending along the radius of the sprocket. During rotation of the drive belt about the horizontal axis 22, the nozzle 32 is supported against the outer surface of the sole of the cutting support and blows air through the sole in order to remove dust and impurities adhering to the bottom of the sole. A collector 34, arranged on the head side of the bristles facing the cutting support, allows collection of the dust thus removed.

[0058] It should be noted that the present invention applies equally well to cutting conveyors that use discharge and loading leads, as well as to cutting conveyors that instead use loading and discharge rakes.

Claims

1. A suction cutting conveyor (10) for an automatic blade cutting machine for sheet material, comprising: the conveyor is housed in a box (12) in which a vacuum is established to hold the sheet material to be cut immobile during the cutting operation; The conveyor (10) of an automatic blade cutter for sheet material comprises a plurality of cutting supports (14, 14') rigidly connected to a drive mechanism that drives the conveyor along linear and curved tracks, each cutting support comprising a plurality of bristles (16; 16') each having a foot (16a) rigidly connected to a sole (18; 18') and a head (16b) located opposite the foot and intended to receive the sheet material to be cut, the sole of each cutting support being elastically deformable according to the track of the drive mechanism, and a transverse channel (25) passing through the sole of the cutting support to allow suction air to pass through the sole.

2. 2. The conveyor of claim 1, wherein the sole (18) of each cutting support has a plurality of parallel geometric shapes extending along a direction perpendicular to the direction of travel of the drive mechanism to enable elastic deformation to follow the trajectory of the drive mechanism.

3. 3. A conveyor as claimed in claim 2, wherein the geometric shape of the sole of the cutting support consists of a plurality of parallel slots (28a, 28b).

4. 4. A conveyor as claimed in claim 3, wherein the slots in the sole comprise external slots (28a) projecting outward relative to an outer surface of the sole and / or internal slots (28b) projecting inward relative to an inner surface of the sole.

5. 5. A conveyor as set forth in claim 4, wherein the slots in the sole comprise alternating external and internal slots (28a) that result in an accordion shape.

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

7. A conveyor according to any one of the preceding claims, wherein the sole (18) of each cutting support is made of plastic material.

8. A conveyor according to any one of the preceding claims, wherein each of the cutting supports is attached by its respective sole to a transmission member of the drive mechanism by means of at least one fastening batten (30).

9. 9. A conveyor as claimed in claim 8, wherein each cutting support is attached to the transmission member of the drive mechanism by at least two fastening battens (30) spaced longitudinally from one another.

10. A conveyor according to any one of the preceding claims, further comprising a device for cleaning the cutting support with air.

11. 11. The conveyor of claim 10, wherein the air cleaning device comprises an air blowing nozzle (32) and a dust collector (34).

12. An automatic blade cutting machine for sheet material, comprising a conveyor (10; 10') according to any one of claims 1 to 11.

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