GB2159458A - A device for trimming veneer - Google Patents

Abstract

A device for trimming off excess veneer extending over an edge of a veneer covered surface of an article comprises a blade member 2 mounted in a jig 1. The jig 1 has jaw assemblies 11 and 12 which slidably engage the article, such that the working edge 21 of the blade member 2 is held in contact with the article. In use the jig 1 is caused to slide along the article so that the blade member 2 contacts the excess veneer and causes it to bend towards the article and to become separated therefrom. <IMAGE>

Description

SPECIFICATION A device for trimming veneer This invention relates to a veneer trimming device.

It is well known to enhance the appearance of articles of furniture manufactured from composite wood based materials, such as chipboard or blockboard, by applying a veneer formed from a decorative material to the exterior surfaces of such articles. A veneer is herein defined as a thin sheet or layer of any suitable decorative material. Commonly used veneers include thin sheets of hardwood, extruded synthetic plastics material and laminated plastics material. Conventionally, these veneers are attached to the surface of an article with an adhesive.

It is normal practice when applying a veneer to a surface of an article, to fix the veneer to said surface so that the freshly applied veneer extends beyond the edges of the surface. The excess is then trimmed off in a subsequent operation, so that in the finished product the veneer extends across the surface up to its edges but not beyond.

In the past this trimming operation has been performed either by hand using a knife-blade or glass paper, or by using a machine having a driven rotatable cutting blade or blades.

If the trimming operation is done by hand considerable care is required in order to avoid removing too much or too little of the veneer and, when a knife-blade is employed, to avoid cutting into the substrate beneath the veneer. If glass paper alone is used to remove the excess veneer, the paper rapidly loses its abrasive qualities and becomes clogged with veneer and adhesive materials.

When the operation is performed industrially using a rapidly rotating cutting blade, means are normally provided so that said blade trims off the required amount of veneer only. However, the blade of this type of tool tends to become hot in use because of the friction between the rapidly moving blade and the veneer being cut. There is often excess adhesive under the protruding veneer, and this adhesive is easily melted by the hot cutting blade. The cutting blade thus becomes clogged with molten adhesive thereby impairing its efficiency.

A further disadvantage inherent in two of the above methods is that sharp blades are required for their success and there will always be a risk of a person receiving an injury from such a blade.

It is an obj ct of the present invention to provide a trimming device which overcomes the disadvantages of the aforementioned trimming devices and methods. According to the present invention there is provided a device for trimming off excess veneer extending over an edge of a veneer covered surface of an article, comprising a blade member having a first surface which adjoins a second surface to define a working edge, wherein the blade member is mounted in a jig which is adapted to slidably locate on the article in such a way that; the edge of the blade member is held in slidable contact with the edge of the article and, when the jig is caused to slide along the work-piece, the first surface of the blade member contacts the excess veneer causing the excess veneer to bend towards the article.

In an embodiment the edge of the blade member lies in a plane which is substantially perpendicular to the veneer covered surface of the article.

In a further embodiment the jig carries a second blade member, in addition to the first blade member, having a first surface which adjoins a surface to define a working edge, which edge engages a second edge of the veneer covered surface in substantially the same way as the working edge of the frist blade member engages the first mentioned edge of said surface.

An advantage of the present invention is that the working edge of the blade member is not required to be sharp, and thus is unable to inflict accidental injury to a person and cannot cause damage to a veneer covered article when in use.

A further advantage of the present invention is that the blade member does not heat up in the way that the rotating blade of the prior art device having such a blade does when in use. Thus the blade member of the present invention cannot become clogged with adhesive.

A specific embodiment of the invention will now be described, by way of non-limiting example only, with reference to the following drawings: Figure 1 is a side view of a device in accordance with the present invention; and Figure 2 is a section on line l-l in Figure 1.

The device illustrated is a hand tool for trimming veneer which has previously been applied to the edge face of a wooden panel. The device will be described as orientated in Figure 1, and comprises a jig 1 and a blade member 2.

The jig is formed having a rectangular parallelepipedic main member 3, having upper and lower horizontal surfaces 4 and 5, first and second vertical side faces 6 and 7 and front and rear vertical surfaces 8 and 9. The main member 3 carries a front jaw assembly 10 and a rear jaw assembly 11 adjacent to its front and rear surfaces 8 and 9 respectively. Each of the jaw assembies 10 and 11 comprises a fixed jaw 12 and an adjustable jaw 13.

Both of the jaws 12 and 13 in each assembly 10 and 11 extends below the lower horizontal surface 5 of the main member 3.

The fixed jaws 12 are rigidly located to the first side face 6 of the main member 3. Each jaw 12 defines a work- piece engaging pad 14 below said main member 3. Both the work-piece engaging pads 14 are in the form of rectangular surfaces which are coplanar with side face 6.

The adjustable jaws 13 are rigidly located adjacent to the second side face 7, be means (not shown) which allow the spacing of the jaws 13 from the second face 7 to be adjusted in the directions of the arrow A. Each jaw 13 defines a workpiece engaging pad 15, similar to pads 14. The pads 14 and 15 lie in parallel planes and the set of pads 14 and 15 on each of the jaw assemblies 10 and 11 face each other below the main member 3.

By adjusting the position of the jaws 13 the spac ing between the pads 14 and 15 may also be adjusted.

A rectangular cross-sectioned channel 26 is formed in each of the jaws 12 and 13 immediately below the lower horizontal surface 5 and above and adjacent to either of the work-piece engaging pads 14 or 15.

The blade member 2 is a rectangular parallelepiped and is formed from a hard material such as steel. The blade member has two end surfaces 16, an upper surface 17, a lower surface 18, an inner side surface 19 and an outer side surface 20. The inner side surface 19 and the lower surface 18 to operate to form a straight working edge 21.

A blade carriage member 22 extends outwardly from the first vertical side 6 of the jig 1 and the blade member 2 is attached to said carriage member 22 by two screws 23 which extend through the blade member 2 and into the carriage member 22.

The blade carriage member 22 serves to hold the blade member 2 rigidly in the operative position as illustrated in the drawings, with the edge 21 contiguous with the first vertical side face 6 of the main member 3 for a majority of its length. A portion of the edge 21 extends below the lower horizontal surface 5, and it is this part of said edge 21 and the adjoining portion of the lower surface 18 which perform the trimming function.

In use, in order to trim the excess veneer from the veneered edge face of a wooden panel, the adjustable jaws 13 are opened so that the panel is a sliding fit between the work-piece engaging pads 14 and 15. The device is placed onto the panel which is gripped between the pads 14 and 15 of the front jaw assembly 10, with the front portion of the lower horizontal surface 5 sitting on the veneer covered edge face of the panel. The excess veneer is accommodated in the channel 16 of the front jaw assembly 10. The device is advanced along the panel in the direction of arrow B, see Figure 1, until the excess veneer is engaged by the lower surface 18 and the working edge 21 of the blade member 2.The surface 18 causes the excess veneer to be bent downwardly and towards the wooden panel, and the working edge 21 engages the veneer immediately above the edge of the panel defined by the veneered edged surface and the adjoining surface of said panel. As the device is further advanced along the panel, the action of the blade member in engaging the veneer as described above causes the excess veneer to be severed from that adhered to the edge surface of the panel. As the device passes along the panel, the panel becomes engaged between the pads 14 and 15 of the rear jaw assembly 11 thus causing the blade member to remain in firm engagement with the panel.

If the device is used to trim the excess veneer from a surface of a work-piece which could not be accommodated in the jaw assemblies 10 and 11, the adjustable jaws 13 should be removed. The device should then be kept in engagement with workpiece by hand pressure.

It must be appreciated that a jig similar to that described above may be fixed in position adjacent to a veneer applying machine, such that the freshly veneered panel passes directly from the veneering machine and into the trimming device. In such an arrangement the jig could advantageously be formed as an integral part of the veneering machine.

Further embodiments include jigs which provide a mount for two blade members, both of which may be adjusted to engage the excess veneer extending over opposite sides of a surface of a workpiece.

Other embodiments include means for causing a blade member to perform an oscillatory motion in addition to its overall linear motion along the work-piece. This oscillatory motion must lie in the plane which includes both the working edge of the blade member and the edge of the work-piece over which the excess veneer extends. In one embodiment the oscillatory motion is parallel to the linear, cutting, motion of the blade or blades.

In yet further embodiments the blade member is in the form of a rotatable wheel-like or annular member, having a first surface in the form of the curved wall of a cylinder and a second surface substantially perpendicular to said first surface.

Said first and second surfaces are adjacent to each other and co-operate to define a circular working edge. The working edge so defined is not required to be sharp. The rotatable member is mounted in a jig so that in use its working edge and first surface (the curved surface) make contact with the workpiece in substantially the same way as the corresponding parts of the fixed blade member do in the specific embodiment described above. The rotatable member however is free to rotate relative to the jig. An example of such a rotatable member is the outer race of a ball race type of bearing, modified by the exclusion of the chamfer which is normally provided between the outer curved surface of said race and its adjacent annular surface, to thereby provide the working edge. In this example the inner race would be fixed to the jig and the outer race would be free to rotate.

Claims (11)

1. A device for trimming off excess veneer extending over an edge of a veneer covered surface of an article, comprising a jig carrying a blade member having first and second adjoining surfaces defining a working edge, wherein in use the jig maintains the working edge of the blade member in slidable contact with the edge of the article, such that when the jig is caused to slide along the article, the first surface of the blade member contacts the excess veneer causing the excess veneer to bend towards the article and to become separated therefrom.

2. A device as claimed in 1 wherein in use, the jig maintains the working edge of the blade member in a plane substantially perpendicular to the veneer covered surface of the article.

3. A device as claimed in Claim 2 wherein a second blade member having first and second adjoining surfaces defining a working edge is mounted in the jig, wherein in use the jig maintains the working edge of the second blade member in slidable contact with the second edge of the article, such that when the jig is caused to slide along the article, the first surfaces of both the blade members contact the excess veneer extending over the first and second edges of the article and, cause the excess veneer to bend towards the article and to become separated therefrom.

4. A device as claimed in Claim 2 wherein the jig includes at least one pair of jaws arranged to engage the article and to hold the working edge of the blade member in slidable contact with the edge of the article.

5. A device as claimed in Claim 4 wherein the jaws are adjustable to accommodate articles of differing widths.

6. A device as claimed in Claim 3 wherein the positions of the first and second blade members are adjustable to accommodate articles of differing widths.

7. A device as claimed in any of the preceding claims wherein means are provided for causing a blade member to perform an oscillatory motion, which lies in a plane which includes both the working edge of the blade member and the edge of the article over which the excess veneer near extends.

8. A device as claimed in any of the preceding claims wherein the blade member or members is a rotatably mounted wheel member, having a first surface in the form of the curved wall of a cylinder and an adjoining second surface, substantially perpendicular to the first surface, said surfaces together defining a circular working edge.

9. A device as claimed in any of the preceding claims further comprising means for propelling the article through the device and past the blade member or members.

10. A veneering machine incorporating a veneer trimming device as claimed in any of the preceding claims.

11. A device for trimming off excess veneer substantially as herein before described with reference to and as shown in the accompanying drawings.