GB1564382A

GB1564382A - Finishing of an edge surface of a sheet or plate

Info

Publication number: GB1564382A
Application number: GB32177A
Authority: GB
Original assignee: Stehle Werkzeug & Maschf
Current assignee: Stehle Werkzeug & Maschf
Priority date: 1976-01-08
Filing date: 1977-01-06
Publication date: 1980-04-10
Also published as: ATA4477A; BE850101A; DE7600322U1; AT347282B; IT1117848B

Description

(54) IMPROVEMENTS IN OR RELATING TO THE FINISHIN G OF AN EDGE SURFACE OF A SHEET OR PLATE (71) We, WERKZEUG-UND MASCHINEN- FABRIK STEHLE GmbH & ; Co. a German Body Corporate, of 50-53 Allgauer Strasse, D-8940 Memmingen, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following state ment :- The present invention relates to the finishing of an edge surface of a sheet or plate (hereinafter referred to, simply, as a "sheet") having a surface layer on each of its major surfaces.

In the processing of chipboard panels which consist of a centre layer formed from pressed chips and two surface layers, it has been proposed to mill the edge surfaces of the chipboard panels. After milling, however, coarse chips from the centre layer again stand up, as a result of which, after the removal of the edge coverings, corrugations may arise on the edge surfaces which adversely affect the appearance of such chipboard panels. In order to remedy this it has been proposed to carry out a subsequent finishing grinding of the edge surfaces by means of grinding discs which process the edge surfaces with their forward or front surface.

When grinding the edge surface with the front surface of a conventional grinding disc the direction of grinding is the same as with milling with the result that the coarse chips ofthe centre layer are only pressed back into the plate, and stand up again after the grinding operation. Also when grinding the edge surface with the front surface of the grinding disc, the edge surface at the place where the grinding disc leaves the chipboard, may easily exhibit breaks.

According to the present invention, there is provided a method of finishing an edge surface of a sheet having a surface layer on each of its major surfaces, wherein the edge surface is finished by means of a rotating tool, the axis of rotation of which is so inclined with respect to the direction of advance of the edge surface relative to the tool, that the tool produces a groove in the edge surface but the tool does not act on the surface layer.

Further according to the invention, there is provided apparatus for finishing an edge surface of a sheet having a surface layer on each of its major surfaces, said apparatus comprising a rotating tool, the axis of rotation of which is so inclined with respect to the direction of advance of the edge surface relative to the tool, that the tool produces a groove in the edge surface but the tool does not act on the surface layers.

In a first embodiment of the invention, the tool is a grinding disc having a front face which is inclined from the area of its cylindrical surface conically towards its axis of rotation. In this case, the axis of rotation of the grinding disc lies in the main plane of the sheet, but is inclined relative to the direction of feed. In this arrangement the tool operates in the manner of a grinding disc which grinds the edge surface with its front face, except that, the front face of the grinding disc is now pivoted away from the edge surface about the forward point of contact in the direction of advance of the sheet.

In another embodiment, the tool is a grinding disc having a cambered cylindrical surface which acts as the grinding surface. In this case, the axis of rotation of the grinding disc does not lie in the main plane of the sheet, but instead extends obliquely to this plane.

This tool operates in the manner of the grinding disc which processes the edge surface with its cylindrical surface, except, however, the plane formed by the grinding disc is now inclined relative to the plane of the sheet. In this case the grinding disc has a width which preferably is several times smaller than the edge height of the plate to be processed. By providing the grinding disc with a cambered cylindrical surface, when the sheet is advanced relative to the grinding disc, the latter is not merely operative by means of its edge between front face and its cylindrical surface.

The tool instead of being a grinding disc, may alternatively be a face-milling cutter or a lateral surface miller.

The invention will be described in greater detail by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure I shows schematically, in side elevation, a grinding disc processing a chipboard sheet with a portion of its front face; Figure 2 is a view, corresponding to Figure 1, in the direction of feed; Figure 3 is a top plan view corresponding to Figure 1; Figure 4 is a schematic side elevation showing a grinding disc processing the edge portion of the sheet with its cylindrical surface; Figure 5 is a view corresponding to Figure 4 in the direction of feed; and Figure 6 is a top plan view corresponding to Figure 4.

In Figure 1 there is shown schematically a chipboard sheet 1 moved in a feed direction V so that its edge surface 2 is processed by a grinding disc 3. As may be seen in particular from Figures 2 and 3, the grinding disc 3 is inclined relative to the edge surface 2 so that the disc 3 only contacts the edge surface 2 at a zone 4 which is forward in the direction of feed; by virtue of the inclination of the grinding disc, its axis 5 of rotation is slanted relative to the direction of advance V. As may be seen from Figures 2 and 3, the front face 6 of the grinding disc 3 is conically inclined relative to the axis of rotation 5, in such a manner that the grinding disc engages the edge surface of sheet 1 not merely with its edge between front face and area of the cylindrical surface. As will be seen from Figures 1 and 3, as a result of this slanting position of the axis 5 relative to the direction of feed V, there is produced in the edge surface of the sheet 1 a groove 7 which, however, does not touch the upper and lower surface layers 8 and 9 of the sheet 1. As the surface layers are not touched no edge breaks can arise at the point of withdrawal of the disc, that is on separating the surface to be processed from the grinding disc.

In the arrangement of Figures 4 to 6, a grinding disc 31 of relatively smaller thickness is used, which acts upon the edge surface 21 of the chipboard sheet 1 with its cylindrical surface 10 which is cambered so as to be of arcuate form in radial section. Due to the cambered form of the cylindircal surface 10 when this surface engages the edge surface 2 of the sheet 1, the disc acts not only with its edge between its front face and its cylindrical surface, but also with other parts of the cylindrical surface. The axis of rotation 5 of the grinding disc 31 is inclined relatively to the direction of feed V of the sheet 1 in such a manner that it is oblique to the main plane of the chipboard panel 1. Here also, the inclined position of the grinding disc 31 is so selected that the cutting length of the grinding disc 31 in the edge surface 2 of the sheet 1 does not touch the upper and the lower surface layers 8 and 9 of the chipboard sheet 1, and therefore there is again formed a groove 7 which does not touch the two surface layers.

Instead of the grinding disc shown in the drawings it is possible to use a face-milling cutter or a lateral surface miller having an inclined axis of rotation so as to form a groove in the edge surface 2 in similar manner to that described above. The direction of feed V is determined by a feeding device 11, for example a guide track represented only schematically here.

As a result of the inclined position of the rotating tools relative to the direction of advance of the sheet, it is achieved that in one operation the coarse chips of the centre layer are cut or shortened, in such a manner that they cannot lead to any undesirable corrugating of an edge covering applied onto the edge surface, and on the other hand breaking of the edges out into the surface layers is avoided in a reliable manner in that the groove formed in the edge surface does not itself touch the surface layers. The depth of the groove is determined by the inclination of the axis of rotation of the tool.

WHAT WE CLAIM IS:- 1. A method of finishing an edge surface of a sheet having a surface layer on each of its major surfaces, wherein the edge surface is finished by means of a rotating tool, the axis of rotation of which is so inclined with respect to the direction of advance of the edge surface relative to the tool, that the tool produces a groove in the edge surface but the tool does not act on the surface layers.

2. A method according to claim 1, wherein the tool is a grinding disc the face of which has a conically-inclined portion adjacent the cylindrical surface of the disc, and said conically-inclined portion constitutes the grinding surface of the disc.

3. A method according to claim 1, wherein the tool is a grinding disc having a cambered cylindrical surface which constitutes the grinding surface of the disc.

4. A method according to claim 1, wherein the tool is a face-milling cutter.

5. A method according to claim 1, wherein the tool is a lateral surface miller.

6. A method according to any one of claims 1, 2, 4 or 5, wherein the axis of the tool lies in the plane of the sheet.

7. A method according to any one of claims 1, 2, 3 or 5, wherein the axis of the tool is inclined to the plane of the sheet.

8. Apparatus for finishing an edge surface of a sheet having a surface layer on each of its major surfaces, said apparatus comprising a rotating tool, the axis of rotation of which

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. may alternatively be a face-milling cutter or a lateral surface miller. The invention will be described in greater detail by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure I shows schematically, in side elevation, a grinding disc processing a chipboard sheet with a portion of its front face; Figure 2 is a view, corresponding to Figure 1, in the direction of feed; Figure 3 is a top plan view corresponding to Figure 1; Figure 4 is a schematic side elevation showing a grinding disc processing the edge portion of the sheet with its cylindrical surface; Figure 5 is a view corresponding to Figure 4 in the direction of feed; and Figure 6 is a top plan view corresponding to Figure 4. In Figure 1 there is shown schematically a chipboard sheet 1 moved in a feed direction V so that its edge surface 2 is processed by a grinding disc 3. As may be seen in particular from Figures 2 and 3, the grinding disc 3 is inclined relative to the edge surface 2 so that the disc 3 only contacts the edge surface 2 at a zone 4 which is forward in the direction of feed; by virtue of the inclination of the grinding disc, its axis 5 of rotation is slanted relative to the direction of advance V. As may be seen from Figures 2 and 3, the front face 6 of the grinding disc 3 is conically inclined relative to the axis of rotation 5, in such a manner that the grinding disc engages the edge surface of sheet 1 not merely with its edge between front face and area of the cylindrical surface. As will be seen from Figures 1 and 3, as a result of this slanting position of the axis 5 relative to the direction of feed V, there is produced in the edge surface of the sheet 1 a groove 7 which, however, does not touch the upper and lower surface layers 8 and 9 of the sheet 1. As the surface layers are not touched no edge breaks can arise at the point of withdrawal of the disc, that is on separating the surface to be processed from the grinding disc. In the arrangement of Figures 4 to 6, a grinding disc 31 of relatively smaller thickness is used, which acts upon the edge surface 21 of the chipboard sheet 1 with its cylindrical surface 10 which is cambered so as to be of arcuate form in radial section. Due to the cambered form of the cylindircal surface 10 when this surface engages the edge surface 2 of the sheet 1, the disc acts not only with its edge between its front face and its cylindrical surface, but also with other parts of the cylindrical surface. The axis of rotation 5 of the grinding disc 31 is inclined relatively to the direction of feed V of the sheet 1 in such a manner that it is oblique to the main plane of the chipboard panel 1. Here also, the inclined position of the grinding disc 31 is so selected that the cutting length of the grinding disc 31 in the edge surface 2 of the sheet 1 does not touch the upper and the lower surface layers 8 and 9 of the chipboard sheet 1, and therefore there is again formed a groove 7 which does not touch the two surface layers. Instead of the grinding disc shown in the drawings it is possible to use a face-milling cutter or a lateral surface miller having an inclined axis of rotation so as to form a groove in the edge surface 2 in similar manner to that described above. The direction of feed V is determined by a feeding device 11, for example a guide track represented only schematically here. As a result of the inclined position of the rotating tools relative to the direction of advance of the sheet, it is achieved that in one operation the coarse chips of the centre layer are cut or shortened, in such a manner that they cannot lead to any undesirable corrugating of an edge covering applied onto the edge surface, and on the other hand breaking of the edges out into the surface layers is avoided in a reliable manner in that the groove formed in the edge surface does not itself touch the surface layers. The depth of the groove is determined by the inclination of the axis of rotation of the tool. WHAT WE CLAIM IS:-

1. A method of finishing an edge surface of a sheet having a surface layer on each of its major surfaces, wherein the edge surface is finished by means of a rotating tool, the axis of rotation of which is so inclined with respect to the direction of advance of the edge surface relative to the tool, that the tool produces a groove in the edge surface but the tool does not act on the surface layers.

4. A method according to claim 1, wherein the tool is a face-milling cutter.

5. A method according to claim 1, wherein the tool is a lateral surface miller.

is so inclined with respect to the direction of advance of the edge surface relative to the tool, that the tool produces a groove in the edge surface but the tool does not act on the surface layers.

9. A method substantially as hereinbefore described with reference to the accompanying drawings.

10. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.

11. A sheet having an edge surface finished by a method according to any one of claims 1 to 7, or claim 9.