BACKGROUND OF THE INVENTION

The invention relates to an assembly of a woodworking device for by means of a planing head planing wooden planks and a grinding device for sharpening the planing head.

It is known to clamp a rectilinear planing blade of a planing head and grind it in a grinding device, particularly a computer-numerical-control grinding device, also called CNC grinding device, which is provided with computer controlled grinding tools. The computer-controlled grinding tools make it possible to grind complex profiled shapes, but in this case can also be used for simple rectilinear grinding processes. Grinding rectilinear blades takes up time from the expensive computer-controlled grinding device.

It is an object of the invention to provide a simple grinding device for grinding rectilinear planing blades.

It is an object of the invention to provide an efficient grinding device for grinding rectilinear planing blades.

SUMMARY OF THE INVENTION

According to a first aspect the invention provides an assembly of a woodworking device having a rotatingly driven planing head for the planing of wooden planks, and a grinding device for sharpening the planing head, wherein the planing head comprises a core and planing blades, which in the rotation direction, are distributed over the core and protrude therefrom, wherein on either side of the core the planing head is provided with a first and second end surface, respectively, which preferably extend parallel to each other, wherein at one of the sides the planing head is provided with an attachment stump protruding from the first end surface, which stump has a circumferential outer surface that conically tapers away from the core, wherein the woodworking device comprises a rotatingly driven planing head holder, wherein the planing head holder is provided with an insertion channel for accommodation of the attachment stump, wherein the insertion channel is internally bounded by a circumferential inner surface that is complementarily shaped with respect to the outer surface of the attachment stump, for entering a play-free, terminable press fit between the attachment stump and the planing head holder, wherein the grinding device comprises a grinding tool, a first bearing and a second bearing that are spaced apart from each other, and a first and second adapter member, wherein the first adapter member is provided with a first shaft to be placed in the first bearing and a first coupling member connected at the outer end of the shaft, wherein the second adapter member is provided with a second shaft to be placed in the second bearing and a second coupling member connected at the outer end of the shaft, wherein during maintenance the planing head is accommodated in the grinding device and the coupling members abut the opposing end surfaces of the removed planing head, wherein the central axes of the shafts -and the rotation central axis of the planing head are in one line in order to form a joint rotation central axis around which the planing head can. be rotated with respect to the grinding tool. The planing head therefore can be accommodated in both the woodworking device and in the grinding device. This can be a simple grinding device that is adapted for rectilinear grinding in the direction of the joint central axis between the bearings

In one embodiment the coupling members are provided with circumferential coupling surfaces that are complementarily shaped with respect to the end surfaces of the planing head, wherein the end surfaces and the corresponding coupling surfaces contact each other so as to abut. The coupling surfaces are able to ensure a play-free coupling between the planing head and the adapter members.

In one embodiment the first and/or second adapter member is provided with a centring recess having a straight cylindrical inner wall, wherein the attachment stump with its widest basis abuts the inner surface of the centring recess. The attachment stump and the centring recess can then be centred with respect to each other.

In one embodiment the planing head is provided on either side with tapped attachment openings situated on the rotation central axis, wherein the adapter members are provided with studs that engage into the tapped attachment openings. In that way an enforced coupling can be effected between the adapter members and the planing head.

In one embodiment the shafts of the adapter members are hollow, wherein the studs extend through the hollow shafts and at the side facing away from the planing head have each been provided with a tensioning knob, large moment can be exerted on the stud by means of the tensioning knob, as a result of which a firm, force-closed coupling between the adapter members and the planing head can be realised.

In one embodiment the attachment stump is designed like a hollow bush, wherein its inner side is provided with a circumferential edge, wherein the woodworking device is provided with a coupling, that is provided with a spreading or pulling portion that engages behind the edge. The pulling or spreading portion is able to effect the press fit and maintain it during planing operations.

In one embodiment the grinding tool is a grinding wheel .

In one embodiment one of the adapter members is provided with two flanges arranged on the shaft, which flanges are spaced apart from each other in order to accommodate one of the bearings in between them. The motion of said adapter in its longitudinal direction is thus limited, as a result of which the position of the planing head with respect to the grinding device is defined by the length of said adapter. The other adapter may for instance be able to shift in its longitudinal direction over the bearing. In that way it is also possible to clamp planing heads of other dimensions in the grinding device.

The invention furthermore relates to a grinding device, suitable and intended for the assembly according to the invention.

The invention furthermore relates to adapter members, suitable and intended for the assembly according to the invention.

According to a second aspect the invention provides a method for in a grinding device sharpening planing blades of a rotatingly driven planing head of a woodworking device for the planing of wooden planks, wherein the planing head comprises a core and planing blades, which in the rotation direction, are distributed over the core and protrude therefrom, wherein on either side of the core the planing head is provided with a first and second end surface, respectively, which preferably extend parallel to each other, wherein at one of the sides the planing head is provided with an attachment stump protruding from the first end surface, which stump has a circumferential outer surface that conically tapers away from the core, wherein the woodworking device comprises a rotatingly driven planing head holder, wherein the planing head holder is provided with an insertion channel for accommodation of the attachment stump, wherein the insertion channel is internally bounded by a circumferential inner surface that is complementarily shaped with respect to the outer surface of the attachment stump, for entering a play-free, terminable press fit between the attachment stump and the planing head holder, wherein the grinding device comprises a grinding tool, a first bearing and a second bearing that are spaced apart from each other, and a first and a second adapter member, wherein the first adapter member is provided with a first shaft to be placed in the first bearing and a first coupling member connected at the outer end of the shaft, wherein the second adapter member is provided with a second shaft to be placed in the second bearing and a second coupling member connected at the outer end of the shaft, wherein during maintenance the planing head is accommodated in the grinding device and the coupling members abut the opposing end surfaces of the removed planing head, wherein the central axes of the shafts and the rotation central axis of the planing head are in one line in order to form a joint rotation central axis around which the planing head can be rotated with respect to the grinding tool, wherein the method comprises taking the planing head out of the woodworking device, placing the planing head between the first and the second adapter member in order to form a shape-retaining unity therewith, placing the shafts of the adapter members in the bearings of the grinding device and activating the grinding tool to sharpen the planing blades of the planing head.

The aspects and measures described in this description and . the claims of the application and/or shown in the drawings of this application may where possible also be used individually. Said individual aspects may be the subject of divisional patent applications relating thereto. This particularly applies to the measures and aspects that are described per se in the sub claims.

SHORT DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of a number of exemplary embodiments shown in the attached schematic drawings, in which:

figure 1 shows a view of a woodworking device according to the invention;

figures 2A-C show views of parts of the woodworking device according to figure 1;

figure 3 shows a view of a grinding device according to the invention;

figure 4 shows a front view of the grinding device according to figure 3;

figure 5 shows a view of parts of the grinding device according to figure 3 and the woodworking device according to figure 1;

figures 6 and 7 show views of the parts according to figure 5;

figure 8 shows a cross-section of the parts according to figure 5;

figure 9 shows a cross-section of an alternative embodiment of parts of the grinding device.

DETAILED DESCRIPTION OF THE DRAWINGS Figure 1 schematically shows a woodworking device 8 for planing a wooden plank 80, comprising a framework 86, three driven conveyor rollers 85 bearing mounted on the framework 86 for in direction A passing through the plank 80 in a supported manner through the woodworking device 8, a drive 87 placed at one side of the conveyance path defined by the conveyor rollers 85, which drive is provided with a planing head holder 81 and a metal planing head 3 secured in the planing head holder 81, which planing head is positioned over the surface to be planed of the plank 80 for rotation about a rotation central axis.

As shown in figures 2A-C the planing head 3 is provided with a core 41 having a straight cylindrical outer surface 30 around the rotation central axis S3. In the core 41 four slots 33 are present that extend parallel to the rotation central axis S3, wherein a metal planing blade 34 is accommodated in each slot 33, which planing blade is secured in the slot 33 by means of four clamping bolts 39. As shown in figure 2B at one side of the core 41 the planing head 3 is provided with an attachment stump 31 having a circumferential outer surface that tapers away from the core 41. Spaced apart from the outer ends of the planing blades 34, the core 41 of the planing head 3 comprises a first end surface 35 and a circumferential second end surface 36 around the foot of the attachment stump 31, which both are oriented perpendicular to the rotation central axis S3.

Within the first end surface 35 the core 41 is provided with a centring recess 42 that is centred with respect to the rotation central axis S3. In the core 41 at the first end surface 35 and the second end surface 36, the planing head 3 is provided with a first attachment opening 37 and second attachment opening 38, respectively, that are situated on the rotation central axis S3, and tapped with inner thread or provided with inner thread.

The planing head holder 81 is provided with a conical insertion channel 82 for accommodation of the conical attachment stump 31 of equal conicity. The planing head holder 81 comprises a puller 83, which engages all round behind a circumferential inner edge 40 of the. conical attachment stump 31, in order to by means of a tensile force in direction T effect a play- free press fit between the conical attachment stump 31 and the insertion channel 82. For the sake of clarity, however, the fit is shown in figure 2B with some intermediate space. The actual fit, however, is pressed and therefore snugly contiguous. The woodworking device 8 is provided with a push button 84 with which the tensile force of the puller 83 can be ended. The planing head 3 thus is removable from the planing head holder 81.

Figures 3 and 4 show a grinding device 9 for grinding the blades 34 of the planing head 3. The grinding device 9 is provided with a dripping tray 90 for collecting oil residues and grinding material, two bearing supports 91 that rise from the dripping tray 90 and at their upper side are provided with supporting blocks or bearings 98, a straight conveyor rail 93 and a column 94 that can be moved over the conveyor rail 93 and thus can be moved in horizontal direction Y. The bearing supports 91 and the bearings 98 are aligned with each other parallel to direction Y. Connected to the column 94 are a grinding wheel 96 and a vertical protective plate 95 situated behind it, which both can be moved in horizontal direction X.

As shown in figures 3 and 4 the grinding device 9 is provided with a first metal adapter member

I and a second metal adapter member 2, for on either side at the end surfaces 35, 36 retaining the planing head 3. Said parts are also shown in the figures 5, 6 and 7.

The first adapter member 1 comprises a first straight cylindrical hollow shaft 10 having a rotation central axis SI and a first straight cylindrical coupling member 11, that is pressed onto the outer end of the first hollow shaft 10. The first coupling member

II comprises a first coupling surface 15 that is complementarily shaped with respect to the first end surface 35 of the planing head 3. The first coupling member 11 is provided with a concentrically situated centring pin 16 that is complementarily shaped with respect to the centring recess 42 of the planing head 3. As shown in figures 6 and 8 the first adapter member 1 is provided with a first stud 12, that fully extends through the first hollow shaft 10 for with a part of the first stud 12 protrude with respect to the length of the first shaft 10, and two flanges 14 that are fixedly connected to the shaft 10. The first stud 12 is provided with a first tensioning knob 13.

The second adapter member 2 comprises a second straight cylindrical hollow shaft 20 having a rotation central axis S2 and a second straight cylindrical coupling member 21, that is pressed onto the outer end of the second hollow shaft 20. The second coupling surface 25 is provided with a concentrically situated straight cylindrical centring recess 26 for accommodating the conical attachment stump 31, wherein the diameter of the recess 26 corresponds with the largest diameter of the conical attachment stump 31.

As shown in figures 7 and 8 the second adapter member 2 is provided with a second stud 22, that fully extends through the second hollow shaft 20 for with a part of the second stud 22 protrude with respect to the length of the second shaft 20. The second stud 22 is provided with a second tensioning knob 23.

In this embodiment the second hollow shaft 20 does not comprise flanges. However, in an alternative embodiment, as shown in figure 9, the second adapter member 2 is provided with two flanges 24 that are fixedly connected to the shaft 20. In this embodiment the first adapter member 1 does not comprise flanges.

As shown in figure 4 the adapter members 1, 2 with the protruding parts of the studs 12, 22 engage onto the internal thread of the -attachment openings 37, 38 of the planing head 3, wherein the coupling surfaces 15, 25 of the adapter members 1, 2 contact the first end surface 35 and the second end surface 36, respectively, of the planing head 3 so as to abut. The central axes SI, S2 and S3 in that case are in each other's extension, in order to form the joint rotation central axis S. As shown in figure 3 the adapter members 1, 2 with their joint central axis S have been placed on the bearings 98 of the grinding device 9.

The method for grinding the planing blades 34 of the planing head 3 in the grinding device according to figure 3 is as follows:

In figures 1, 2A-B the situation is shown in which the planing head 3 is accommodated in the planing head holder 81 of the woodworking device 8. The puller 83 is pulled in direction T, as a result of which the planing head 3 is secured in the planing head holder 81. The planing head 3 has rotated and the blades 34 of the planing head 3 have planed material away from the plank 80. In the course of time the blades 34 have become blunt and need to be sharpened. For that purpose the knob 84 is operated in order to relax the puller 83 and remove the planing head 3.

In figure 5 the situation is shown in which the adapter members 1, 2 and the planing head 3 with central axes SI, S2 and S3 are positioned in each other's extension. The first coupling surface 15 and the second coupling surface 25 are situated straight opposite the first end surface 35 and the second end surface 36, respectively.

In figure 4 the situation is shown in which the first stud 12 and the second stud 22 by means of a rotary motion of the first tensioning knob 13 and second tensioning knob .23, respectively, have bee.n screwed in the thread of the first attachment opening 37 and the second attachment opening 38,. respectively. The first coupling surface 15 and the first end surface 35 and the second coupling surface 25 and the second end surface 36, respectively, have contacted each other in an abutting manner, which contacts are maintained by the tension in the studs 12, 22. Said tension is realised by turning the tensioning knobs 13, 23. The assembly of the adapters 1, 2 and the planing head -3 thus forms one play-free and aligned unity. The conical attachment stump 31 is in that case centred and at the foot accommodated fittingly in the centring recess 26. The central axes SI, S2 and S3 jointly form the rotation central axis S. The assembly of the adapter members 1, 2 and the planing head 3 is now ready to be placed in the bearings 91 of the grinding device 91.

In figure 3 the situation is shown in which the assembly of the adapter members 1, 2 and the planing head 3 have been placed in the bearings 91. The flanges 14 of the first shaft 10 confine the bearing 91 on both sides, as a result of which the first adapter member 1 is position-fixed in direction Y. The position of the second adapter member 2 with respect to the bearing 91 depends on the length of the planing head 3. The adapter members 1, 2 therefore are suitable in combination with planing heads 3 of various linear measures .

The planing head 3 is placed near the grinding wheel 96 and is freely rotatable about the joint rotation central axis S. The grinding wheel 96 can be started after which the column 94 is movable in direction Y on the conveyor belt 93. The rotating grinding wheel 96 will in that case move past one of the blades 34. By moving the protective plate 95 in direction X with respect to the column 94, it can be achieved that the grinding wheel 96 touches one of the blades 34 in passing by and thus effects a grinding treatment .

The above description is included to illustrate the operation of preferred embodiments of the invention and not to limit the scope of the invention. Starting from the above explanation many variations that fall within the spirit and scope of the present invention will be evident to an expert.