Device for holding a vibrating blade on a blade holder of a cutting machine, and blade intended to cooperate with such a device

Abstract

The invention relates to a device for holding a vibrating steel blade on a blade holder of a cutting machine, comprising a blade holder (4) having a notch (14) that is able to receive an upper end of a blade (2), means (22) for magnetically holding the upper end of the blade in the notch of the blade holder in a direction perpendicular to a longitudinal axis (X-X) of the blade, and at least one stop (20) which is formed in the notch and is able to be housed in a cut-out (2a) made in the upper end of the blade in order to ensure absorption of cutting forces.

Description

Description Title of the invention: Device for holding a vibrating blade on a blade holder of a cutting machine and blade intended to cooperate with such a device Technical Field

[0001] The present invention relates to the general field of automatic cutting of a flexible material by a vibrating blade of a cutting machine. It relates more particularly to the holding of the blade on the blade holder of such a cutting machine.

[0002] One field of application of the invention is that of the automatic cutting of parts in a flexible textile or non-textile material (such as leather), in particular in the clothing, furniture or automotive upholstery industry. Prior art

[0003] A known method for automatically cutting parts from a flexible material consists of bringing the material onto a fixed or mobile cutting support of the cutting table, in the form of a single ply or a stack of plies forming a mattress, and cutting the parts by means of a cutting head moving above the cutting support of the table according to a previously defined placement program.

[0004] Typically, the cutting head of such a machine comprises a steel blade that is mounted on a blade holder and vibrates vertically along the direction of its cutting edge to cut the material. A rotating blade guide acts as a slide for the blade and ensures its rotation.

[0005] The blade is generally vibrated by a connecting rod-crank system which drives the blade in a back-and-forth translational movement. For example, the translational movement has an amplitude of 25mm and a vibration frequency of around 100Hz.

[0006] Furthermore, to ensure that the path of the pieces to be cut is followed in the material, it is necessary for the cutting tool to exert a rotational movement of the blade around its longitudinal axis. This rotational movement is generally ensured by means of the blade guide and the presser foot of the cutting tool.

[0007] Typically, to allow these translational and rotational movements, the blade is held in position at its upper end in the blade holder by means of one or more assembly screws. The assembly and disassembly of the blade for replacement is carried out using a tool, for example a hexagon key type.

[0008] In particular, with this type of assembly, replacing a worn blade requires manual access to the assembly screw(s) and the use of a suitable wrench. However, the blade holder of the cutting head of a cutting machine generally has restricted access, which may require prior disassembly of elements of the cutting head. In addition, the appropriate tool must be available, and the tightening force to be applied to the screw when fitting the new blade is difficult to calibrate. All of these operations therefore involve a considerable loss of time for users of the cutting machine. Statement of the invention

[0009] The main aim of the present invention is therefore to propose a device for holding a vibrating blade on a blade holder of a cutting machine which does not have the aforementioned drawbacks.

[0010] According to the invention, this object is achieved by means of a device for holding a vibrating steel blade on a blade holder of a cutting machine, comprising: a blade holder having a notch capable of receiving an upper end of a blade, - means for magnetically holding the upper end of the blade in the notch of the blade holder in a direction perpendicular to a longitudinal axis of the blade, and - at least one lug formed in the notch and capable of being housed in a cutout made in the upper end of the blade in order to ensure that cutting forces are absorbed. [OOllJThe device according to the invention is remarkable in that it provides means for magnetically holding the upper end of the blade in the notch of the blade holder in a direction perpendicular to a longitudinal axis of the blade (holding the blade in the notch of the blade holder is without mechanical attachment). This magnetic holding ensures transmission of the cutting movement without play. In addition, the cutting forces linked to the back-and-forth translational movement of the blade are taken up by obstacles resulting from the shape of the interface between the blade and the notch of the blade holder, and not by friction forces.

[0012] In addition, the device according to the invention allows the blade to be mounted and dismounted on the blade holder without the need for a specific tool (wrench, screwdriver, etc.). Indeed, the blade can be mounted and dismounted manually. This great ease of mounting and dismounting saves considerable time for users of the cutting machine.

[0013] According to one embodiment, the blade holder comprises at least one magnet assembled inside the notch and capable of establishing a flat support with a flat surface of the upper end of the blade so as to ensure magnetic retention of the upper end of the blade in the notch of the blade holder. This embodiment has the advantage of being simple to implement. Furthermore, the flat support between the magnet(s) and the blade makes it possible to ensure better retention of the blade.

[0014] According to another embodiment, the notch of the blade holder is magnetized so as to ensure magnetic retention of the upper end of the blade in the notch of the blade holder.

[0015] According to yet another embodiment, the notch of the blade holder comprises a ferromagnetic metal and the upper end of the blade comprises a magnet so as to ensure magnetic retention of the upper end of the blade in the notch of the blade holder.

[0016] Whatever the embodiment, the notch may comprise a bottom having a flat surface and is delimited laterally by two edges projecting relative to the bottom.

[0017] In this case, the lug may extend from a lower end of one of the edges of the notch towards the other edge in a direction substantially perpendicular to the longitudinal axis of the blade. Such a lug has the advantage of ensuring good absorption of cutting forces while acting as a foolproofing device for the blade.

[0018] Alternatively, the lug may be made by a pin extending from the bottom of the notch in a direction substantially perpendicular to the longitudinal axis of the blade. Such a lug has the advantage of making it very easy to mount the blade.

[0019] The invention also relates to a vibrating steel blade for a cutting machine intended to cooperate with the holding device as defined above, the blade comprising an upper end capable of being housed in the notch of the blade holder and of being held therein by the magnetic holding means, the upper end of the blade comprising at least one cut-out capable of receiving the lug formed in the notch.

[0020] Preferably, the blade is made of high speed steel.

[0021] The invention also relates to an assembly of a vibrating steel blade as defined above on a blade holder of a cutting machine by means of a holding device as defined previously. Brief description of the drawings

[0022] [Fig. 1] Figure 1 is a schematic view showing an example of assembly according to the invention of a vibrating blade on a blade holder of a cutting machine.

[0023] [Fig. 2A-2B] Figures 2A and 2B are a magnifying glass of Figure 1 showing the blade holder notch with and without a blade.

[0024] [Fig. 3A-3B] Figures 3A and 3B show alternative embodiments of the lug formed in the notch of the blade holder of the device according to the invention. Description of the embodiments

[0025] The invention relates to the automatic cutting of a flexible material by a vibrating blade of a cutting machine, in particular by a steel blade, for example high-speed steel.

[0026] As shown schematically in Figure 1, the blade 2 of such a cutting machine is typically assembled on a blade holder 4 of the cutting head and is vibrated vertically in the direction of its cutting edge in order to cut the material.

[0027] The vibration of the blade 2 is for example achieved by a system of connecting rod 6 and crank 8 which drives the blade in a back-and-forth translational movement in the direction of the longitudinal axis XX of the blade.

[0028] Furthermore, the blade 2 is guided in its translational movement by a set of rollers 10 distributed over the entire height. These rollers 10 also make it possible to partially absorb the forces due to cutting.

[0029] In addition, a rotating blade guide 12 serves as a slide for the blade 2 and ensures its rotation around its longitudinal axis XX.

[0030] As shown more precisely in Figures 2A and 2B, the blade holder 4 has a notch 14 which is capable of receiving an upper end of the blade 2.

[0031] For example, this notch 14 is of substantially rectangular shape and may comprise a bottom 16 having a substantially flat surface and is delimited laterally by two edges 18 which project relative to the bottom 16 and which extend along the longitudinal axis XX of the blade.

[0032] Of course, it is possible to consider other geometries for the shape of the notch intended to receive the upper end of the blade.

[0033] Furthermore, still according to the invention, a lug 20 is formed in the notch 18. In the exemplary embodiment of FIGS. 2A and 2B, this lug 20 extends from a lower end of one of the lateral edges 18 of the notch in the direction of the other edge in a direction substantially perpendicular to the longitudinal axis XX of the blade.

[0034] The upper end of the blade 2 according to the invention comprises a cutout 2a having a shape substantially complementary to that of the lug 20 (in the example of FIGS. 2A and 2B, the lug and the cutout of the blade have a substantially rectangular shape).

[0035] This complementary shape between the lug and the notch of the blade forms a key to avoid an error when mounting the blade on the blade holder. This complementary shape also ensures that the cutting forces of the blade are absorbed.

[0036] Still according to the invention, at least one magnet 22 is assembled inside the notch 14 in order to establish a flat support with a corresponding flat surface of the upper end of the blade and to ensure magnetic retention of the upper end of the blade in the notch of the blade holder.

[0037] The number, shape and arrangement of the magnet(s) assembled inside the blade holder notch may vary depending on applications and notch shape.

[0038] Likewise, different types of magnets can be used. For example, you can choose a magnet made of neodymium boron, samarium-cobalt alloy, or any other ferrite. The magnet(s) can be glued to the bottom of the notch.

[0039] The blade 2 is thus held in the notch 14 of the blade holder 4 by magnetism without resorting to any mechanical attachment (such as a screw, for example).

[0040] In connection with Figures 3A and 3B, we will now describe variant embodiments of the lug formed in the notch of the blade holder of the device according to the invention.

[0041] In the embodiment variant of [Fig.3A], the notch 14' of the blade holder is of substantially rectangular shape and is delimited laterally by two edges 18' which project relative to the bottom of the notch and which extend along the longitudinal axis XX of the blade.

[0042] Furthermore, in this embodiment variant, the lug is produced by a pin 20' which extends from the bottom of the notch 14' in a direction substantially perpendicular to the longitudinal axis of the blade. For example, the pin 20' is centered on the longitudinal axis XX of the blade.

[0043] As for blade 2', it has a cutout 2a' which has a complementary shape to the 20' pin, that is to say a circular cutout.

[0044] This variant has the advantage that the blade is easy to machine to make the cut 2a'. On the other hand, the shape of the pin does not allow it to act as a key.

[0045] In the embodiment variant of [Fig.3B], the notch 14" of the blade holder is also of substantially rectangular shape and is delimited laterally by two edges 18" which project relative to the bottom of the notch and which extend along the longitudinal axis XX of the blade.

[0046] Furthermore, in this variant embodiment, the lug is double and each lug 20" extends from a lower end of one of the lateral edges 18" of the notch towards the other edge in a direction substantially perpendicular to the longitudinal axis XX of the blade.

[0047] Of course, the upper end of the 2" blade has two 2a" cutouts of complementary shapes to the two 20" lugs of the notch.

[0048] The presence of two lugs has the advantage of ensuring excellent absorption of cutting forces. On the other hand, the contact surface with the magnets can be restricted and the final assembly presents a risk of hyperstaticity.

[0049] Furthermore, it should be noted that other means of magnetically holding the upper end of the blade in the notch of the blade holder can be envisaged.

[0050] Thus, in an alternative embodiment not shown in the figures, the notch of the blade holder can be magnetized so as to ensure magnetic retention of the upper end of the blade in the notch of the blade holder.

[0051] Alternatively, in another variant embodiment not shown in the figures, the notch of the blade holder may comprise a ferromagnetic metal and the upper end of the blade may comprise a magnet so as to ensure magnetic retention of the upper end of the blade in the notch of the blade holder.

Claims

Demands

1. Device for holding a vibrating steel blade on a blade holder of a cutting machine, comprising: - a vibrating steel blade (2; 2'; 2") for cutting machine; - a blade holder (4) having a notch (14; 14'; 14") suitable for receiving an upper end of the blade, - means for magnetically holding (22) the upper part of the blade in the notch of the blade holder in a direction perpendicular to a longitudinal axis (XX) of the blade, and - at least one lug (20; 20'; 20") formed in the notch and capable of fitting into a cutout (2a; 2a'; 2a") made in the upper end of the blade in order to ensure a transfer of cutting forces.

2. Device according to claim 1, wherein the blade holder (4) comprises at least one magnet (22) assembled inside the notch and capable of establishing a flat support with a flat surface of the upper end of the blade so as to ensure magnetic retention of the upper end of the blade in the notch of the blade holder.

3. Device according to claim 1, wherein the notch of the blade holder is magnetized so as to ensure magnetic retention of the upper end of the blade in the notch of the blade holder.

4. Device according to claim 1, wherein the notch of the blade holder comprises a ferromagnetic metal and the upper end of the blade comprises a magnet so as to ensure magnetic retention of the upper end of the blade in the notch of the blade holder.

5. Device according to any one of claims 1 to 4, wherein the notch (14; 14'; 14") comprises a bottom (16) having a flat surface and is laterally delimited by two rims (18; 18'; 18") projecting from the bottom.

6. Device according to claim 5, wherein the lug (20) extends from a lower end of one of the edges (18) of the notch (14) towards the other edge in a direction substantially perpendicular to the longitudinal axis of the blade.

7. Device according to claim 5, wherein the lug is made by a pin (209) extending from the bottom of the notch (14') in a direction substantially perpendicular to the longitudinal axis of the blade.

8. Device according to any one of claims 1 to 8, wherein the retention of the blade in the notch of the blade holder is devoid of mechanical attachment.

9. Vibrating steel blade (2; 2'; 2") for cutting machine intended to cooperate with the holding device according to any one of claims 1 to 9, comprising an upper end adapted to fit into the notch (14; 14'; 14") of the blade holder and to be held therein by magnetic holding means (22), the upper end of the blade comprising at least one cutout (2a; 2a'; 2a") adapted to receive the lug formed in the notch.

10. Blade according to claim 10, wherein it is made of high-speed steel.

11. Assembly of a vibrating steel blade according to any one of claims 10 and 11 on a blade holder of a cutting machine by means of a retaining device according to any one of claims 1 to 9.

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