EP0345570A1 - Clamping indexable cutters in a rotary head for working wood or similar material - Google Patents

Abstract

Clamping indexable cutters in a rotary head for working wood or similar material, composed of a cutter (3) formed by a tip of metal carbide or another suitable metal, arranged between a support tip (4) and a clamping jaw (5), the whole being inserted in a corresponding longitudinal groove (2) situated in a respective rotary head (1) radially or parallel to the axis of rotation of the latter, the said clamping jaw (5) being pushed by suitable driving screws (13), penetrating through the opening of one face (21) of the longitudinal groove (2) against the opposite face of the same, causing the clamping of the said cutter (3) and associated support tip (4), the said face (22) opposite the said longitudinal groove (2) preferably being provided with a plurality of small longitudinal grooves (221) which are parallel and equally spaced from one another, and adapted to engage in the corresponding grooves (43) situated on the corresponding outer face of the said support tip (4), the abovementioned support tip (4) and cutter (3) being provided with reciprocal fixing means (44-33/45-35) adapted to interact with one another when they are clamped by the driving screws (13). These fixing means (44-33/45-35) preferably consist of a projecting part situated on the inner face of the said support tip (4) which engages in a corresponding grooved part situated on the opposing inner part of the said cutter (3) or vice versa. This projecting part may consist of at least one raised longitudinal edge (44) which extends along the said inner face of the abovementioned support tip (4) parallel to the axis of rotation of the rotary head (1), or of at least one projecting stub (45) which engages respectively in a corresponding groove (33) or in a corresponding hole (35) situated on the inner face of the abovementioned cutter (3). <IMAGE>

Description

The present invention relates to a device for fixing hard metal knives on rotating knife-holder heads particularly used on machines for working wood or similar material.

There are different types of rotating heads on which suitable knives are attached and which, mounted on the relative machine tools, are used for profiling elements of wood or similar material.

As is known, these rotating heads generally consist of cylindrical bodies provided on their periphery with longitudinal grooves suitably shaped and equipped with means for fixing special plates of appropriate metal, constituting the knives of the resulting tool. The knives normally used can be constituted by a single-body element, clamped in the respective groove by a jaw pushed by screws conveniently placed. Normally, these knives are fixed in a single position, which makes any resharpening operations considerably difficult.

Other knives, similar to the previous type, consist of two elements brazed together, and precisely, a first carbide plate constituting the knife itself and a second steel plate forming the support element on which is fixed the previous brochure. Even this solution has the disadvantages of the previous one.

A subsequent solution provides for the use of a support element which is provided on one face with a plurality of slight longitudinal incisions capable of engaging on the corresponding incisions located on the face of the groove, against which it is tightened. . The plate forming the knife element can result in such a way brazed on the above support element or also separate.

In the first case, when the knife-support group is clamped by the pressure jaw, a secure fixing is obtained while in the second case, the plate constituting the knife element, resulting only retained by simple clamping between two flat surfaces, cannot guarantee sufficient reliability. The use of plates constituting the knife element, constructed of very expensive material, leads, in the case where one wishes to modify the profile, the complete substitution of the same which, clearly, results very expensive.

The object of the present invention is to compensate for the above-mentioned drawbacks, and for others which are very well known, obtaining, simultaneously, a very rational arrangement which guarantees the maximum reliability of use, making it possible, moreover, to very easily carry out resharpening. , both on the back and on the front of the knife, and, moreover, to be able to vary in a wide range of re-use, the shape of the profile of the knife. These advantages, as well as many others, are obtained with the device forming the object of the present invention, which provides for the use of a knife formed, which is known, by a metal carbide plate or other suitable material. , which results clamped between a support plate and a clamping jaw, the whole resulting inserted in the corresponding longitudinal groove being on a head, the aforesaid clamping jaw resulting pushed by suitable control screws towards the opposite part of the groove , causing the clamping of the aforementioned knife and of the relative support plate, called the opposite part of the above-mentioned groove, being preferably provided with a plurality of light longitudinal grooves which are parallel and equidistant from each other, capable of engaging in the corresponding grooves located on the corresponding external face of the said support plate, the whole being well known, and which is characterized in that the aforementioned support plate and the aforementioned knife are provided with reciprocal fixing means, capable of interacting with each other, when they result in being tightened by the appropriate control screws.

According to another characteristic, the aforesaid support plate is provided with at least one projecting part, capable of engaging in the corresponding grooved part located on the aforementioned knife. A further characteristic consists in the fact that the aforesaid projecting part, being on the aforesaid support plate, is constituted by at least one raised longitudinal edge and the aforementioned grooved part, being on the aforesaid knife, is constituted by at least one corresponding groove, in which the aforesaid raised longitudinal edge results being able to engage. Another achievable form of the aforesaid reciprocal fixing means consists of at least one stud projecting from the said support plate and which can engage in a corresponding hole located in the aforementioned knife.

• - la fig. 1 indique, par l'entremise d'une vue partiellement sec­tionnée, le détail du dispositif en objet appliqué sur une tête tournante;
• - la fig. 2 indique, par l'entremise de vue perspective, une pre­mière forme réalisable possible des moyens de fixage réciproque, entre la plaquette de support et le couteau;
• - la fig.3 indique, avec une vue perspective éclatée, une utlérieure forme réalisable des sudits moyens de fixage réciproque.

The whole, achievable in a preferred form and by way of example only and not limiting, will be described below in more detail with reference to the appended drawing in which:

• - fig. 1 indicates, through a partially sectioned view, the detail of the device in object applied to a rotating head;
• - fig. 2 indicates, by means of perspective view, a first possible feasible form of the reciprocal fixing means, between the support plate and the knife;
• - Fig.3 indicates, with an exploded perspective view, an utlérieur workable form of the sudits means of reciprocal fixing.

In fig. above, the common rooms are indicated with the same reference number.

With particular reference to fig. 1 we can observe the rotating head 1 in which the longitudinal grooves 2 are located, capable of containing the knife and the relative clamping group. These longitudinal grooves 2, of which only one results, illustrated in FIG. to which reference is made, consist of cavities penetrating into the cylindrical body 11 of the aforesaid rotating head 1 in a star or parallel to its axis of rotation defining two faces parallel to each other which, relative to the direction of rotation, respectively result in forming a first anterior face 21, and a second posterior face 22. The external angle of the abovementioned face 21, will result provided with a chamfer 211, moreover, on the abovementioned anterior face 21 there are suitable threaded holes 12 in which are screwed the respective pressure screws 12. The aforesaid rear face 22, results provided with a plurality of slight longitudinal grooves 221, which, as can be seen in FIG. 1, have a triangular section and are located side by side so as to completely cover the surface of the said posterior face 22. Inside the said longitudinal groove 2, there is a group of elements consisting of a knife 3 , a support 4 and a clamping jaw 5.

The above knife 3, as can be seen in FIG. 2 is constituted, as is known, by a plate 31 constructed of suitable metal. Initially, this plate 31 has a parallelepiped shape, and the side forming the back 32 is conveniently shaped in a notorious manner to obtain the desired profile. Near the opposite side, on the side which will result adjacent to the support 4 during mounting, there is a longitudinal groove 33 parallel to the same side.

The support 4, as can be seen in FIG. 2, is basically constituted by a steel plate 41, at the lower end of which there is a protruding rim 42, having the shape "L".

On the face opposite to that of the aforesaid rim 42, there is a plurality of light longitudinal grooves 43, complementary to the above-mentioned longitudinal grooves 221. Above the aforementioned projecting rim 42 there is a later projecting longitudinal rim 44, having very reduced dimensions and which will result able to engage in the aforementioned longitudinal groove 33 of the aforementioned knife 3.

Finally, the aforesaid clamping jaw 5 is conspicuously constituted by a metal bar 51, fundamentally parallelepiped, the upper edge of which will eventually result, if appropriate, with the curved part 52, connecting to the element 211 and which, in addition, provided with a suitable groove 53 in which the heads of the pressure screws 13 can engage in abutment.

The operation of the device is obvious.

The knife 3 is applied to the relative support 4 and everything is introduced into the relative longitudinal cavity 2, into which the clamping jaw 5 is then also introduced, and the control screws 13 are screwed which will be in contact with the surface of the groove 53; in this way, the entire group consisting of the support 4, the knife 3 and the clamping jaw 5, will be clamped between the surface of the rear face 22 and the heads of the control screws 13. As can be seen, especially on fig. 1, the projecting rim 42 of the support 4 has a thickness slightly less than the thickness of the plate 31, which constitutes the above-mentioned knife 3; in this way, when the control screws 13 are fully screwed, the thrust of the clamping jaw 5 develops completely only against the aforementioned knife 3 which thus surely results clamped between the said jaw 5 and the aforesaid support 4. The flange protruding longitudinal 44 will presently have dimensions slightly smaller than those of the relative longitudinal groove 33 of the above knife 3, so that the tightening can cause perfect adhesion of the opposite surfaces of the knife 3 and relative support 4, in addition, the position of the knife 3 will result defined by the only pressing of the lower edge against the upper surface of the protruding edge 42 of the support 4. The functions of the longitudinal grooves 43 and 221 are obvious and well-known, and indeed, they always make it possible to bring the support 4 exactly and surely into the appropriate working position. The execution described makes it possible to obtain, compared to those known, large advantages which are synthetically indicated below.

Initially, the two elements, knife 3 and relative support 4, are profiled separately with appropriate tools and consequently the successive profiling or sharpening of the back can be carried out directly with the group mounted on the respective head. It is even possible to sharpen the knife 3 on its front. The mechanical tightening of the knife 3 also allows a better yield of the hard metal plate constituting the same, compared to the soldering. By gradually moving the support 4 towards the outside, and consequently even the relative knife 3, there is always the possibility of successively recovering the whole while maintaining, with the appropriate resharpening of the back, a constant working diameter. Finally, the plates 31 constituting the knife 3 and the relative supports 4 can be amply recycled. More precisely, these elements, after having been used with a first profile, can be reprofiled with other profiles compatible with the remaining dimensions.

Finally, it is clear that the presence of the longitudinal edge 44, being on the respective support 4 and which engages in the corresponding longitudinal groove 33 of the knife 3, allows a reciprocal attachment which, with the attachment produced by the reciprocal engagement of the longitudinal grooves 43, located on the support 4, in the corresponding longitudinal grooves 221 located on the rear face 22 of the relative longitudinal groove 2, ensures total reliability of the device which thus results in maximum safety as to operation. Indeed, without this attachment system, if, for any reason, the attachment due to the screwing of the control screws 13, is insufficient, the knife 3 could come out, by centrifugal force, when the rotating head 1 is placed in rotation. The attachment system between the knife 3 and the relative support 4 can vary, for example, as is clearly indicated in FIG. 3, by placing, in place of the rim 44, two projecting studs 45 which must engage in correspondence with the holes 35, located on the plate 31 of the knife 3. These and other variants can be made to the device in subject without, on the other hand, going beyond the limits of what has been described above and claimed with reference to the appended drawings and therefore from the field of protection of this industrial monopoly.

Claims (4)

1) The device for the removable fixing of hard metal knives on rotating heads for working with wood or similar material, composed of a knife (3) formed by a metal carbide plate or other suitable material, placed between a support plate (4) and a clamping jaw (5), the resulting whole inserted into a corresponding longitudinal groove (2) located in a respective rotating head (1) parallel or in a star to the axis of rotation of the latter, the aforesaid clamping jaw (5), resulting pushed by suitable control screws (13), penetrating through one face (21) of the longitudinal groove (2) against the opposite face of the same, causing the clamping of the aforesaid knife (3) and relative support plate (4), the aforesaid face (22) opposite to the aforesaid longitudinal groove (2), being preferably provided with a plurality of light longitudinal grooves (211) parallel and at equal distance between they, able to e swim in the corresponding grooves (43) located on the corresponding external face of the aforesaid support plate (4), the whole being known, this device being characterized by the fact that the aforesaid support plate (4) and the aforesaid knife (3) are provided with reciprocal fixing means (44-33 / 45-35) capable of interacting with each other, when they result in being tightened by the aforementioned control screws (23). 2) Device according to claim 1, characterized in that the aforesaid fixing means (44-33 / 45-35) are preferably constituted by a projecting part located on the internal face of the aforesaid support plate (4 ) suitable for engaging in the corresponding grooved part located on the internal surface opposite the aforementioned knife (3) or vice versa. 3) The device according to claim 1 and 2, characterized by the fact that the said protruding part is constituted by at least one raised longitudinal edge (44) which extends transversely along the internal face of the support plate (4) or of the knife (3) and that the said part grooved is constituted by at least one corresponding groove (33), located on the inner face of the counter element in which the aforesaid raised longitudinal edge (44) results to be able to engage. 4) Device according to claims 1 and 2, characterized in that the aforesaid projecting part consists of at least one stud (45) and that the said grooved part consists of a corresponding hole (35) in which the above nipple (45) results to be able to engage.

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