Apparatus for holding a vibrating blade in a blade holder of a cutting machine, and a blade intended to cooperate with such an apparatus

Abstract

The present invention relates to an apparatus for holding a vibrating steel blade in a blade holder of a cutting machine, and includes a blade holder (4) having a notch (14) capable of receiving the upper end of the blade (2), means (22) for magnetically holding the upper end of the blade along a direction perpendicular to the longitudinal axis (X-X) of the blade within the notch of the blade holder, and at least one lug (20) that can be received in a notch (2a) formed at the upper end of the blade to reliably absorb the cutting force and is formed in the notch.

Description

Technical Field

[0001] The present invention relates to the general field of automatic cutting of flexible materials by the vibrating blade of a cutting machine. More particularly, it relates to the holding of the blade on the blade holder of such a cutting machine.

[0002] One application field of the present invention is the automatic cutting of pieces from flexible materials such as woven or non-woven fabrics (such as leather), and it is particularly applied in the clothing, furniture, or automotive upholstery industries.

Background Art

[0003] Known methods for automatically cutting pieces from flexible materials consist in loading the material onto a fixed or movable cutting support of a cutting table in the form of a single ply or a stack of plies forming a mattress, and cutting the pieces by a cutting head that moves above the cutting support of the table according to a predefined placement program.

[0004] Typically, the cutting head of such a cutting machine consists of a steel blade that is assembled to a blade holder and is vibrated vertically along the direction of its sharp edge to cut the material. A rotating blade guide functions as a slide for the blade and ensures the rotation of the blade.

[0005] The blade is generally vibrated by a connecting rod - crank system that makes the blade move in a translational motion back and forth. For example, the translational motion has an amplitude of 25 mm and a frequency on the order of 100 Hz.

[0006] Furthermore, in order to ensure the tracking of the trajectory of the pieces cut from the material, the cutting tool needs to perform a rotational movement of the blade about its longitudinal axis. This rotational movement is generally ensured via the blade guide and the bar of the cutting tool.

[0007] Typically, to enable these translational and rotational movements, the blade is held at its upper end position within the blade holder by one or several assembly screws. The attachment and removal of the blade for replacement are reliably performed, for example, using a tool of the hex key type.

[0008] In particular, in this type of assembly, in order to replace a worn blade, it is necessary to manually access the assembly screws and prepare an appropriate wrench. However, the blade holder of the cutting head of the cutting machine is generally restricted in access, and it may be necessary to remove the elements of the cutting head beforehand. Furthermore, it is necessary to prepare an appropriate tool, and it is difficult to calibrate the tightening force applied to the screws when attaching a new blade. Therefore, all of these operations involve a significant loss of time for the user of the cutting machine. SUMMARY OF THE INVENTION

[0009] Accordingly, the main object of the present invention is to propose an apparatus for holding a vibrating blade on a blade holder of a cutting machine that does not have the aforementioned drawbacks. MEANS FOR SOLVING THE PROBLEM

[0010] According to the present invention, this object is achieved thanks to an apparatus for holding a vibrating steel blade on a blade holder of a cutting machine, the apparatus comprising - a blade holder having a notch capable of receiving the upper end of the blade, - means for magnetically holding the upper end of the blade along a direction perpendicular to the longitudinal axis of the blade within the notch of the blade holder, - at least one lug formed in the notch and capable of being received in a notch formed at the upper end of the blade to reliably absorb the cutting force, and comprising.

[0011] The device according to the invention is noted for providing means for magnetically holding the upper end of the blade along a direction perpendicular to the longitudinal axis of the blade within the notch of the blade holder (holding the blade within the notch of the blade holder does not involve mechanical attachment). This magnetic holding ensures the transmission of a cutting movement without clearance. Furthermore, the cutting forces associated with the translational movement of the blade back and forth are absorbed not by frictional forces but by obstacles resulting from the shape of the interface between the blade and the notch of the blade holder.

[0012] Furthermore, the device according to the invention enables the attachment and detachment of the blade to the blade holder without the need to use specific tools (such as wrenches, drivers, etc.). In fact, the attachment and detachment of the blade can be done manually. Since the attachment and detachment are thus very simple, the user of the cutting machine can save a considerable amount of time.

[0013] According to one embodiment, the blade holder comprises at least one magnet incorporated within the notch so as to ensure magnetic holding of the upper end of the blade within the notch of the blade holder and capable of establishing a planar bearing with the plane of the upper end of the blade. This embodiment has the advantage of being easy to implement. Furthermore, the planar bearing between the magnet and the blade ensures better holding of the blade.

[0014] According to another embodiment, the notch of the blade holder is magnetized so that the upper end of the blade is securely held by magnetic force within 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 that the upper end of the blade is securely held by magnetic force within the notch of the blade holder.

[0016] Regardless of the embodiment, the notch can comprise a bottom having a plane, and is laterally delimited by two rims protruding with respect to the bottom.

[0017] In this case, the lug can extend from the lower end of one rim of the notch towards the other rim along a direction substantially perpendicular to the longitudinal axis of the blade. Such a lug has the advantage of ensuring good absorption of the cutting force while serving as a key for the blade.

[0018] Alternatively, the lug can be formed by a pin extending from the bottom of the notch along a direction substantially perpendicular to the longitudinal axis of the blade. Such a lug has the advantage that the attachment of the blade becomes very easy.

[0019] The present invention also relates to a vibrating steel blade for a cutting machine intended to cooperate with the holding device defined above, the blade comprising an upper end that can be received in the notch of the blade holder and can be held therein by magnetic holding means, the upper end of the blade including at least one notch capable of receiving the lug formed in the notch.

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

[0021] The present invention also relates to an assembly in which the vibrating steel blade defined above is attached to a blade holder of a cutting machine via the holding device defined above.

Brief Description of the Drawings

[0022]

Figure 1

[0023]

Figure 2A

Figure 2B

[0024]

Figure 3A

Figure 3B

Mode for Carrying Out the Invention

[0025] The present invention relates to a vibrating steel blade of a cutting machine, particularly a steel blade, for example, for automatically cutting flexible materials made of high-speed steel.

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

[0027] The blade 2 is vibrated, for example, by a connecting rod 6 - crank 8 system that drives the blade to reciprocate linearly along the longitudinal axis X - X of the blade.

[0028] Furthermore, the blade 2 is guided in its linear motion by a set of rollers 10 distributed at any height. These rollers 10 also make it possible to partially absorb the force due to cutting.

[0029] Furthermore, a rotating blade guide 12 functions as a slide for the blade 2 and ensures rotation about its longitudinal axis X - X.

[0030] As specifically shown in FIGS. 2A and 2B, the blade holder 4 has a notch 14 that can receive the upper end of the blade 2.

[0031] For example, this notch 14 can consist of a bottom 16 that is substantially rectangular in shape and has a substantially planar surface, and is delimited laterally by two rims 18 that project with respect to the bottom 16 and extend along the longitudinal axis X-X of the blade.

[0032] Of course, it is also possible to assume other shapes for the shape of the notch for receiving the upper end of the blade.

[0033] Furthermore, also according to the present invention, a lug 20 is formed in the notch 18. In the exemplary embodiments of FIGS. 2A and 2B, this lug 20 extends from the lower end of one of the transverse rims 18 of the notch towards the other rim along a direction substantially perpendicular to the longitudinal axis X-X of the blade.

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

[0035] This complementarity of shape between the lug and the notch of the blade forms a key for avoiding errors when attaching the blade to the blade holder. This complementarity of shape also ensures the absorption of the cutting force of the blade.

[0036] Furthermore, according to the present invention, at least one magnet 22 is assembled in the notch 14 in order to establish a planar bearing with the corresponding plane of the upper end of the blade and to ensure the magnetic retention of the upper end of the blade within the notch of the blade holder.

[0037] The number, shape and arrangement of the magnets assembled within the notch of the blade holder can vary according to the application and the shape of the notch.

[0038] Similarly, different types of magnets can also be used. For example, it is possible to select magnets made of neodymium boron, samarium cobalt alloy, or other ferrites. The magnet can be adhered to the bottom of the notch.

[0039] The retention of the blade 2 within the notch 14 of the blade holder 4 is effected magnetically without relying on mechanical attachment (e.g., screw type).

[0040] Next, with reference to FIGS. 3A and 3B, a modification of the embodiment of the lug formed in the notch of the blade holder of the device according to the present invention will be described.

[0041] In a modification of the embodiment of [FIG. 3A], the notch 14' of the blade holder is substantially rectangular in shape and is laterally delimited by two rims 18' that project from the bottom of the notch and extend along the longitudinal axis X-X of the blade.

[0042] Furthermore, in this modification of the embodiment, the lug is formed by a pin 20' that extends from the bottom of the notch 14' along a direction substantially perpendicular to the longitudinal axis of the blade. For example, the pin 20' is at the center of the longitudinal axis X-X of the blade.

[0043] The blade 2' has a shape complementary to the pin 20', i.e., a circular notch 2a'.

[0044] This modification of the embodiment has the advantage that the machining of the blade to form the notch 2a' is easy. On the other hand, the shape of the pin does not ensure a key function.

[0045] In a modification of the embodiment of [FIG. 3B], the notch 14'' of the blade holder is also substantially rectangular in shape and is laterally delimited by two rims 18'' that project from the bottom of the notch and extend along the longitudinal axis X-X of the blade.

[0046] Furthermore, in this modification of the embodiment, the lug is double, and each lug 20'' extends from one lower end of the lateral rim 18'' of the notch towards the other rim along a direction substantially perpendicular to the longitudinal axis X-X of the blade.

[0047] Of course, at the upper end of the blade 2'', there are two notches 2a'' with a shape complementary to the two lugs 20'' of the notch.

[0048] The presence of the two lugs has the advantage of ensuring excellent absorption of the cutting force. On the other hand, the contact surface with the magnet is limited, and the final assembly involves the risk of hyperstatism.

[0049] It should also be noted that other means for magnetically holding the upper end of the blade within the notch of the blade holder can be envisioned.

[0050] Therefore, in one variant of an embodiment not shown in the figures, the notch of the blade holder can be magnetized to ensure magnetic holding of the upper end of the blade within the notch of the blade holder.

[0051] Alternatively, in another variant of an embodiment not shown in the figures, the notch of the blade holder can be provided with a ferromagnetic metal, and the upper end of the blade can be provided with a magnet to ensure magnetic holding of the upper end of the blade within the notch of the blade holder.

Claims

1. 1. A device for holding an oscillating steel blade in a blade holder of a cutting machine, comprising: - Vibrating steel blades for cutting machines (2; 2'; 2''); a blade holder (4) having a notch (14; 14'; 14'') capable of receiving the upper end of said blade; - means (22) for magnetically holding the upper end of the blade in the notch of the blade holder along a direction perpendicular to the longitudinal axis (XX) of the blade; at least one lug (20; 20'; 20'') formed in a notch (2a; 2a'; 2a'') and receivable in the notch formed in the upper end of the blade to reliably absorb cutting forces; An apparatus comprising:

2. 2. The device according to claim 1, wherein the blade holder (4) comprises at least one magnet (22) that is integrated into the notch of the blade holder and that is capable of establishing a planar bearing with the plane 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. 2. The apparatus of claim 1, wherein the notch in the blade holder is magnetized to securely magnetically hold the top end of the blade within the notch in the blade holder.

4. 10. The apparatus of claim 1, wherein the notch in the blade holder comprises a ferromagnetic metal and the top end of the blade comprises a magnet such that the top end of the blade is securely magnetically held within the notch in the blade holder.

5. 5. A device according to any one of claims 1 to 4, wherein the notch (14; 14'; 14'') has a bottom with a flat surface and is bounded laterally by two rims (18; 18'; 18'') projecting relative to the bottom.

6. 6. The apparatus of claim 5, wherein the lug (20) extends from a lower end of one of the rims (18) of the notch (14) toward the other rim along a direction substantially perpendicular to the longitudinal axis of the blade.

7. 6. The device of claim 5, wherein the lug is formed by a pin (20') extending from the bottom of the notch (14') along a direction substantially perpendicular to the longitudinal axis of the blade.

8. An apparatus according to any preceding claim, wherein the retention of the blade in the notch of the blade holder is free of mechanical attachment.

9. An oscillating steel blade (2; 2'; 2'') for a cutting machine, intended to cooperate with a holding device according to any one of claims 1 to 4, having an upper end that can be received in the notch (14; 14'; 14'') of the blade holder and held therein by magnetic holding means (22); The upper end of the blade includes at least one notch (2a; 2a'; 2a'') capable of receiving the lug formed in the notch.

10. The blade of claim 9, wherein the blade is made of high speed steel.

11. 10. An assembly comprising an oscillating steel blade as claimed in claim 9 attached to a blade holder of a cutting machine via a holding device as claimed in claim 1.

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