CORNER JOINT BETWEEN THE END PORTIONS OF TWO BOARD-LIKE MEMBERS

Abstract: A corner joint (1) is established between the end portions of two board-like members (2, 3), preferably made of wood, in a frame, especially for joining furniture parts. The end portion of the first member (2) is provided with at least one projecting part (5) engaging in one or more corresponding mortises (7) in the end portion of the second member (3). The two members (2, 3) are held together by means of one or more securing means (13), such as wooden pegs. The projecting part or parts (5) of the first member (2) and the corresponding mortise or mortises (7) of the second member (3) are wedge-shaped. The end portion of the first member (2) is further provided with a mainly box-type projection (6) abutting one end face (9) of the second member (3). The securing means (13) are elongated and extend through the box-type projection (6) of the first member (2) and into the end portion of the second member (3). The members (2, 3) of the corner joint (1) are secured with respect to each other against forces in any given direction, and, if desired, the corner joint can be easily separated without damaging the members.

Description: Title: Corner Joint Between the End Portions of Two Board-Like Members Field of the invention The invention relates to a corner joint between the end portions of two board-like members, preferably made of wood, in a frame, especially for joining furniture parts, the end portion of the first member being provided with at least one projecting part substantially parallel to one of the long end edges of said member and engaging in one or more corresponding mortises in the end portion of the second member, said members being held together by means of one or more securing means. Description of the Prior Art EP patent application 0 479 767 describes a corner joint between two members provided with interacting projecting, part and mortise, said members being secured with respect to each other by means of glue or by means of undercutting the mortise. However, this is not a satisfactory solution, as gluing requires the ends to be pressed together while the glue is drying. Moreover, the members are not easily separated once the corner joint is established. If the members of the corner joint are undercut, said members will not be secured in the longitudinal direction of the projecting part or parts, unless said part or parts are directly pressed into the mortise, the latter requiring an exact dimensioning of the members with respect to each other. Summary of the Invention The object of the invention is to provide a corner joint of the above- mentioned type, said corner joint being able to secure the members with respect to each other against forces in any given direction, while at the same time - if desired - being easily separated without damaging the members. The corner joint according to the invention is characterized in that the projecting part or parts of the first member and the corresponding mortise or mortises of the second member are substantially wedge- shaped, and that the end portion of the first member is further provided with a mainly box-type projection adjacent to one end face of the second member, and that the securing means are elongated and extend through the box-type projection of the first member and into the end portion of the second member. When assembled, the members of the corner joint are thus secured with respect to each other against forces in any given direction. As soon as the securing means are removed, the members are no longer held together. The corner joint is easily assembled and separated and moreover, it is easy to manufacture. According to the invention the securing means can comprise stud means such as wooden pegs arranged mainly orthogonal to the large outer side face of the box-type projection of the first member. This is a particularly easy way to assemble the corner joint manually without the use of special tools. When wooden pegs are used and not completely impressed during assembly, in other words when a section of said pegs stands proud of the members, the corner joints have a particularly attractive/interesting appearance which may be exploited for design purposes. Moreover, according the invention, the securing means can be screws, such as screws with self-cutting threads, providing a particularly easy way to separate the corner joint. Furthermore, according to the invention, the projecting part or parts of the first member can be intersected by at least one securing means in such a way that the intersection area - seen in cross-section orthogonal to the longitudinal axis of the securing means - corresponds to only part of the cross-sectional area of the securing means. This embodiment allows for a greater degree of constructional freedom. In a prefered embodiment of the invention, the projecting part or parts of the first member as well as the end portion of the second member can be provided with a number of drilled holes, the securing means being guided through said holes and fastened by an interference fit. This ensures a particularly reliable assembly of the corner joint. Finally, according to the invention, the projecting parts of the first member can be present in a number of two or three and together define a zigzag shape. This is a particularly advantageous embodiment, if the first member is considerably thicker relative to the second member, since the contact area between the two members can be significantly enlarged thus increasing the rigidity of the corner joint. Brief Description of the Drawing The invention and particularly advantageous embodiments are described in greater detail below and with reference to the accompanying drawing in which Fig. 1 shows a perspective view of one embodiment of the corner joint according to the invention, the first and second member of said corner joint being clearly visible, Fig. 2 shows a cross-sectional view along the line II-II of Fig. 1 , Fig. 3 shows a rear view of the embodiment of Fig. 1 with the second member being removed; this Fig. shows clearly how the hole for a securing means partially intersects the wedge-shaped projecting part, Fig. 4 shows the same view as Fig. 3 but with the hole completely intersecting the wedge-shaped projecting part, Fig. 5 shows a side view of a second embodiment of the corner joint, and Fig. 6 shows a side view of an embodiment of the corner joint, the wooden pegs being provided with a longitudinal hole, and a tool in the form of a thumbscrew for screwing into the hole in order to separate the corner joint; the thumbscrew is shown removed from the wooden peg, and the wooden peg is shown removed from the board member, Fig. 7 shows a side view of the two board members of the corner joint with said members separated. Detailed Description of the Prefered Embodiment The corner joint 1 shown in Figs. 1 and 2 is established between the end portions af a first board-like member 2 and a second board-like member 3, preferably made of wood, in a frame, especially for joining of furniture parts. The end portion of the first member 2 is provided with a wedge-shaped projecting part 5, said part engaging in a corresponding wedge-shaped mortise 7 in the end portion of the second member 3. The end portion of the first member 2 is further provided with a substantially box-type projection 6 adjacent to one end face 9 of the second member 3. The two members 2 and 3 are held together by one or more securing means 13 such as four securing means as shown in Fig. 1 . The securing means 13 are elongated and extend through the box-type projection 6 of the first member 2 into the end portion of the second member 3. The securing means 13 may be stud means such as wooden pegs having a circular cross-section as shown in Figs. 1 and 2, said stud means being arranged substantially orthogonal to the large outer side face of the box-type projection 6 of the first member 2. As is apparent from Fig. 2, the wooden pegs 13 intersect the box-type projection 6 of the first member 2. Furthermore, the wooden pegs 13 intersect the wedge-shaped projecting part 5 in such a way that the intersection area - seen in cross-section orthogonal to the longitudinal axis of the securing means 13 - corresponds to only part of the cross- sectional area of the securing means 13. The wooden pegs 13 are not completely impressed so that a section of said pegs stands proud of the members. Thus said pegs contribute to an attractive and/or interesting appearance of the corner joint which can be exploited for design purposes. The securing means may also be screws, such as screws with self- cutting threads, providing a particularly easy way to separate the corner joint. Fig. 3 shows a rear view of the first member 2 with the second member 3 being removed. This embodiment corresponds to the one shown in Figs. 1 and 2. Fig. 3 shows particularly clearly in which way the holes 18 for the securing means (not shown) intersect the wedge-shaped projecting part 5. In this case the intersection area - seen in cross- section orthogonal to the longitudinal axis of the securing means 13 - corresponds to 50% of the cross-section of the securing means. The intersection area may, however, be any desired proportion of the cross- sectional area of the securing means. This embodiment allows for a greater degree of constructional freedom. Fig. 4 shows a rear view of the first member 2 in another embodiment of the invention, the projecting part 5 of the first member 2 as well as the end portion of the second member (not shown) being provided with a number of drilled holes 18, the securing means (not shown) being guided through said holes and fastened by an interference fit. In yet another embodiment of the corner joint (not shown) according to the invention the holes for the securing means can be arranged such that the securing means do not intersect the projecting part or parts of the first member. Fig. 5 shows a second embodiment of the corner joint, where the first member 2' has two wedge-shaped projecting parts 16, 17 defining a zigzag shape. This is a particularly advantageous embodiment, if the first member 2' is considerably thicker relative to the second member 3', since the contact area between the two members can be significantly enlarged thus increasing the rigidity of the corner joint. Fig. 6 shows the same embodiment of a corner joint as Figs. 1 and 2, the securing means 13, however, being made of a wooden peg provided with a hole 15 for screwing a separating tool in the form of a thumbscrew 14 into said hole. Fig. 7 shows two board members 2, 3 of a corner joint according to the invention. The acute end 5a of the wedge-shaped projection is cut off and the acute end 7a of the wedge-shaped cut-out 7 is cut off. The acute end 22a of the wedge-shaped projection 22 and the acute end 20a of the wedge-shaped cut-out 20 are also cut off. This reduces notch fatigue. It is also conceivable to round the tips instead of uniformly cutting them off. Flattening or rounding is not absolutely necessary. When a corner joint according to the invention is used in a frame construction, where additional rigidity is desired, a plate can be mounted on the back side of the frame construction or position inside a groove in the board members provided at the inner face of the corner joint close to the back side of the frame construction. Gluing battens made of solid wood on the end portions of the corner joint for the mortises to be milled into said battens permits the use of a board material of reduced strength. Said battens also enhance the ornamental effect. The invention is not restricted to the above-mentioned embodiments. The board members may, for example, be made of plastics, pressed wood or other materials. The securing means may also be conical pins or have another shape, they may be made of metal, plastics or other materials. The corner joint according to the invention can also be described by the Swedish expression "en halvoppen gradsink".

Claims: Claims 1. Comer joint (1; 1') between the end portions of two board-like members (2, 3; 2', 3'), preferably made of wood, in a frame, especially for joining furniture parts, the end portion of the first member (2; 2') being provided with at least one projecting part (5; 16, 17) substantially parallel to one of the long end edges of said member and engaging in one or more corresponding mortises (7) in the end portion of the second member (3; 3'), said members (2, 3; 2', 3') being held together by means of one or more securing means (13), characterized in that the projecting part (5) or parts (16, 17) of the first member (2; 2') and the corresponding mortise or mortises (7) of the second member (3; 3') are substantially wedge-shaped, and that the end portion of the first member (2; 2') is further provided with a mainly box-type projection (6; 6') adjacent to one end face (9; 9') of the second member (3; 3'), and that the securing means (13) are elongated and extend through the box- type projection (6; 6') of the first member (2; 2') and into the end portion of the second member (3; 3'). 2. Corner joint according to claim 1,character-ized in that the securing means (13) comprise stud means such as wooden pegs arranged mainly orthogonal to the large outer side face of the box-type projection (6; 6') of the first member (2; 2'). 3. Corner joint according to claim 1 or 2, c h a r a c -t e r i z e d in that the securing means (13) are screws, such as screws with self-cutting threads. 4. Corner joint according to claim 1, 2 or 3, c ha rac -te rized in that the projecting part (5) or parts (16, 17) of the first member (2; 2') are intersected by at least one securing means (13) in such a way that the intersection area - seen in cross-section orthogonal to the longitudinal axis of the securing means (13) - corresponds to only part of the cross-sectional area of the securing means (13). 5. Corner joint according to one or more of claims 1-4, c h a ra cte rized in that the projecting part (5) or parts (16, 17) of the. first member (2; 2') as well as the end portion of the second member (3; 3') are provided with a number of drilled holes (18), the securing means (13) being guided through said holes and fastened by pre-fitting. 6. Corner joint according to one or more of claims 1-5, c h a racte rized in that the projecting parts (16, 17) of the first member (2') are present in a number of two or three and together define a zigzag shape. 7. Corner joint according to claim 2, c ha racte r -ized in that the stud means (13) is provided with an elongated hole (15) for a tool (14), such as a thumbscrew, to be screwed in to separate the corner joint. 8. Corner joint according to claim 1, c ha racter -ized in that the tips (5a, 20a) of the wedge-shaped projection (5) and the cut-out (20) of the first member (2) are flattened or rounded and that the tips (22a, 7a) of the wedge-shaped projection (22) and the cut-out (7a) of the second member (3) are flattened or rounded.

Inventors: NOCIEVSKI GIORGI, NOCIEVSKI, GIORGI
Applicants: IKEA OF SWEDEN AB, NOCIEVSKI GIORGI, NOCIEVSKI, GIORGI
Application year: 1996
Main classification: F16B12
IPC codes: F16B12