Joint assembly

Abstract

In an aspect there is provided a joint assembly 16 for panel board materials, comprising: a first member 14 comprising a tongue 22 extending from a surface 26 of the first member 14, the tongue 22 comprising a first groove 24 in a side 28 of the tongue 22; wherein at least a portion of the side 28 of the tongue 22 including the first groove 24 extends generally perpendicular to the surface 26 of the first member 14; and a second member 12 comprising: a second groove 32 in a surface 36 of the second member 12, the second groove 32 being arranged to receive the tongue 22; and a lip 34 extending into the second groove 32; wherein, in an assembled position, the tongue 22 is arranged to slot into the second groove 32 and the lip 34 is arranged to slot into the first groove 24 thereby to join the first and second members 14, 12.

Claims

1. A joint assembly for panel board materials, comprising: a first member comprising a tongue extending from a surface of the first member, the tongue comprising a first groove in a side of the tongue; wherein at least a portion of the side of the tongue including the first groove extends generally perpendicular to the surface of the first member; and a second member comprising: a second groove in a surface of the second member, the second groove being arranged to receive the tongue; and a lip extending into the second groove; wherein, in an assembled position, the tongue is arranged to slot into the second groove and the lip is arranged to slot into the first groove thereby to join the first and second members; wherein the lip is formed from a relatively hard material and the tongue is formed from a relatively soft material; wherein the sides of the first groove are generally perpendicular to the side of the tongue in which the first groove is located; and wherein the sides of the second groove are generally perpendicular to the surface of the second member in which the first groove is located.

2. A joint assembly according to claim 1, wherein an upper surface of the lip is continuous with the surface of the second member.

3. A joint assembly according to claim 1, wherein the first groove is located at a base of the tongue.

4. A joint assembly according to claim 1, wherein the first and second members are pieces of panel material.

5. A joint assembly according to claim 4, wherein the tongue is on an edge of the first member.

6. A joint assembly according to claim 5, wherein the tongue is rebated.

7. A joint assembly according to claim 4, wherein the panel material is a fiberboard material.

8. A joint assembly according to claim 7, wherein the lip is formed from a relatively hard outer part of a fiberboard material and the tongue is formed from a relatively soft inner part of a fiberboard material.

9. A joint assembly according to claim 7, wherein the first and second members are formed from a single piece of fiberboard material.

10. A joint assembly according to claim 1, wherein the first and second members are joined by an interference fit between the lip and first groove.

11. A joint assembly according to claim 1, wherein, in the assembled position, the first member is perpendicular to the second member.

12. A joint assembly according to claim 1, wherein the tongue and lip are crenelated such that the tongue can be located into the second groove from above the second groove.

13. A joint assembly according to claim 1, wherein the tongue is machined from only one side of the first member.

14. A joint assembly according to according to claim 1, wherein the second groove and lip are machined from only one side of the second member.

15. A method of manufacturing a joint assembly comprising: providing a first member; forming a tongue extending from a surface of the first member; forming a first groove in a side of the tongue; wherein at least a portion of the side of the tongue including the first groove extends generally perpendicular to the surface of the first member; providing a second member; and forming a second groove in a surface of the second member, the second groove being arranged to receive the tongue, and a lip extending into the second groove; wherein, in an assembled position, the tongue is arranged to slot into the second groove and the lip is arranged to slot into the first groove thereby to join the first and second members; wherein the lip is formed from a relatively hard material and the tongue is formed from a relatively soft material; wherein the sides of the first groove are generally perpendicular to the side of the tongue in which the first groove is located; and wherein the sides of the second groove are generally perpendicular to the surface of the second member in which the first groove is located.

16. The method of claim 15, wherein at least one of: forming a tongue extending from a surface of the first member; forming a first groove in a side of the tongue; and forming a second groove in a surface of the second member, the second groove being arranged to receive the tongue, and a lip extending into the second groove; comprises using a 3-axis computer numerically controlled (CNC) router.

17. A non-transitory software product arranged to perform the method of claim 16.

18. A joint assembly for panel board materials, comprising: a first member comprising a tongue extending from a surface of the first member, the tongue comprising a first groove in a side of the tongue; wherein at least a portion of the side of the tongue including the first groove extends generally perpendicular to the surface of the first member; and a second member comprising: a second groove in a surface of the second member, the second groove being arranged to receive the tongue; and a lip extending into the second groove; wherein, in an assembled position, the tongue is arranged to slot into the second groove and the lip is arranged to slot into the first groove thereby to join the first and second members; wherein the lip is formed from a relatively hard material and the tongue is formed from a relatively soft material; wherein the first and second members are pieces of panel material; wherein the tongue is on an edge of the first member; and wherein the tongue is rebated.

19. A joint assembly according to claim 18, wherein the sides of the first groove are generally perpendicular to the side of the tongue in which the first groove is located.

20. A joint assembly according to claim 19, wherein the sides of the second groove are generally perpendicular to the surface of the second member in which the first groove is located.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) FIGS. 1a and 1b show a joint assembly according to the present invention;

(2) FIG. 2a shows the joint assembly from a different angle;

(3) FIGS. 2b and 2c show the way in which the joint assembly is assembled;

(4) FIG. 3a shows a view of the unassembled joint assembly;

(5) FIG. 3b shows a further view of the unassembled joint assembly;

(6) FIG. 4a shows the joint assembly in an unassembled position; and

(7) FIG. 4b shows the joint assembly in an assembled position.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

(8) FIGS. 1a and 1b show a joint assembly 16 according to the present invention. The joint assembly 16 comprises a first member 14 and a second member 12, which fit together to form the joint assembly 16. The first member 14 and second member 12 are pieces of panel material, specifically fiberboard material.

(9) The first member 14 comprises a male part referred to as the tongue 22. The tongue 22 extends from an edge surface 26 of the first member 14 at a right angle (i.e. perpendicular) to the surface 26. The tongue 22 is rebated in the first member 14, such that the tongue 22 is less wide than the first member 14 as a whole. The tongue 22 is generally rectangular in shape, although it will be appreciated that other shapes are possible.

(10) The tongue 22 includes a first groove 24 in a side 28 of the tongue 22 (i.e. the side that is rebated away from the edge of the first member 14). The first groove 24 is located proximate the surface 26 (i.e. at a base or proximal end of the tongue 22). The sides of the first groove 24 are generally perpendicular to the side 28 of the tongue 22 in which the first groove 24 is present. Accordingly, all of the angles on and around the tongue 22 are 90 degree angles.

(11) The second member 12 comprises a female part referred to as the second groove 32. The second groove 32 is provided in a face surface 36 of the second member 12, with the sides of the second groove 32 being perpendicular to the surface 36 of the second member 12 in which the groove is located.

(12) The second member 12 further comprises a lip 34 which extends into the second groove 32. The lip 34 is located proximate the surface 36 in which the second groove 32 is located, and an upper surface of the lip 34 is continuous with the surface 36 in which the groove is located. A lower surface of the lip 34 is parallel to the upper surface of the lip 34. The lip 34 is formed by undercutting the second groove 32. Accordingly, all of the angles in and around the second groove 32 are 90 degree angles.

(13) The width of the second groove 32 is slightly greater than the width of the tongue 22 and the depth of the second groove 32 is slightly greater than the height of the tongue 22 (i.e. the extension of the tongue 22 away from the edge surface 26), such that the tongue 22 can fit into the second groove 32.

(14) Similarly, the width of the first groove 24 is configured to be slightly smaller (or the same) as the width of the lip 34 and the depth of the first groove 24 is slightly smaller (or the same) than the extension of the lip 34 into the first groove 24, such that the lip 34 can fit into the first groove 24 in an interference fit. In alternative embodiments, the lip 34 may be smaller than the first groove 24 so as to provide a less tight fit.

(15) The first and second members 14, 12 can be fitted into an assembled position by the first member 14 being moved relative to the second member 12 so as to slot the tongue 22 into the second groove 32 and the lip 34 into the first groove 24. This assembled position is shown in FIG. 1b. The lip 34 and first groove 24 form a “hook” in the face surface 36 of the second member 12, preventing the first and second member 14, 12 from being separated by the tongue 22 being pulled out of the second groove 32 (from above). Similarly, the interference between the lip 34 and the tongue 22 prevents the tongue 22 being directly inserted into the groove 32 from above in at least some positions. In such a manner, the first member 14 may be joined to the second member 12 via the described joint assembly 16, with the first member 14 extending perpendicular to the second member 12.

(16) FIG. 2a shows the joint assembly of FIG. 1a from an alternative angle, at 90 degrees to the view shown in FIG. 1a. As is visible in FIG. 2a, the tongue 22 and lip 34 are crenelated (i.e. they are discontinuous, with the discontinuities forming a regular pattern). The crenellations shown in FIG. 2a are exaggerated for visibility. The crenellations 39, 29 in the lip 34 and the tongue 22 allow the tongue 22 to be inserted into the second groove 32 from above in a position where the lip 34 and tongue 22 do not interfere.

(17) In more detail, the lip 34 is cut so as to form a crenelated pattern at the surface of the second groove 32, being made up of wider sections (where the lip 34 is not present) and narrower sections (where the lip 34 is present). This pattern is visible in FIG. 2a.

(18) Similarly, the tongue 22 is cut so as to include a crenelated pattern, formed of narrower portions (i.e. the crenellations 29 themselves) and wider portions 22a (forming the main body of the tongue as described above). The first groove 24 extends all the way through the wider portions 22a of the tongue 22, but not through the crenellations 29—in other words, the material of the tongue 22 is wider at the first groove 24 than at the crenellations 29, and wider at the wider portions 22a than at the first groove 24. The inclusion of a thin portion of material in the crenellations 29 of the tongue 22 (rather than no material at all) may improve the strength of the tongue 22. Providing the first groove 24 all the way through each of the wider portions 22a of the tongue 22 may improve the length and therefore the strength of the connection between the first and second members 14, 12.

(19) FIG. 2b shows the joint assembly 16 of FIG. 2a in which the tongue 22 has been inserted into the second groove 32. FIG. 2c shows the joint assembly 16 of FIG. 2b in which the first and second members 14, 12 have been slotted into the assembly position. Once the tongue 22 has been inserted into the second groove 32, the first and second members 14, 12 may be moved relative to each other to engage the lip 34 with the first groove 24, thereby preventing removal of the tongue 22 from the second groove 32 from above as previously described. As will be appreciated, the use of crenellations means that it is only necessary to move the members a short distance relative to each other to assemble the joint assembly 16, which may improve ease of assembly.

(20) Since the tongue 22 may be inserted into the second groove 32 from above in certain positions, the second groove 32 does not need to extend to the edges of the second member 12 in order to allow the tongue 22 to enter the second groove 32. Accordingly, as shown in FIGS. 2a to 2c, the second groove 32 does not extend to either end of the surface 36 of the second member 12 in which the second groove 32 is located, which may improve the strength of the second member 12. The use of a groove which does not extend to the edge may also allow the groove to be machined anywhere on the face and at any angle.

(21) The fit between the lip 34 and second groove 32 is generally tight enough to hold the first and second member together in the absence of any external force (other than normal gravity). In some use cases, this fit will be sufficient for use. In other use cases, the joint assembly 16 may be augmented by further fastenings, such as glue or screws. The joint may be undone by reversing the fitment described with reference to FIGS. 2a to 2c.

(22) FIGS. 3a and 3b show views of the unassembled joint assembly.

(23) As mentioned, the first and second members are formed from panelboard materials. Specifically, the first and second members are formed from a fiberboard material, such as edgebanded melamine faced chipboard (MFC). Other types of fiberboard material, in particular medium density fiberboard (MDF), are well known. Fiberboard materials are very prevalent throughout the woodwork and furniture industry. A particular property of fiberboard materials is that they often include a relatively hard outer portion (which are treated or otherwise manufactured to provide a hard outer surface) and a relatively soft inner portion (which are generally untreated, because there is no need to do so).

(24) The present invention uses these properties to provide improvements to the joint assembly 16. As will be appreciated, the lip 34 is continuous with the surface 36 of the second member 12 in which the second member 12 is provided. Accordingly, the lip 34 comprises (or consists of) the hard outer portion of the material. The tongue 22 (including the first groove 24) is rebated into the first member 14, and so is formed out of the soft inner portion of the material (at least on the part of the tongue 22 having the first groove 24). Accordingly, the joint assembly 16 includes a hard part of the material which joins with a soft part of the material. In use, this allows for the soft tongue 22 to deform slightly under pressure from the hard lip 34 in an interference fit, which may provide an improved fit between the first and second member.

(25) The particular structure of the joint assembly 16 may provide for improved manufacturing of the joint assembly 16. In particular, the fact that the all of the angles and around the tongue 22 and in and around the second groove 32 are 90 degree angles may allow the tongue 22 and/or lip 34 and second groove 32 to be machined using a conventional 3-axis CNC router (with an autochange cutter) from one side (i.e. without a need to turn or reposition the piece out of which the first and/or second member are being formed). In particular, the lip 34 may be readily formed by undercutting the second groove 32 using a CNC keyhole cutter, whereas such an operation may be difficult or even impossible to do by hand.

(26) In more detail, the tongue 22 may be machined entirely from a face of the first member 14, where manufacturing comprises only simple manufacturing operations (where the order of the following is merely exemplary)—cutting the piece to size, cutting a rebate to form the tongue 22, cutting the crenellations 29, cutting the first groove 24, and any necessary finishing.

(27) Similarly, the lip 34 and second groove 32 may be formed entirely from a face of the second member 12, where manufacturing comprises only simple manufacturing operations (where the order of the following is merely exemplary)—cutting the second groove 32 (in narrower form), undercutting the groove (using a keyhole cutter) to form the crenelated lip 34, and any necessary finishing.

(28) The ease of manufacturing which may be provided by the present invention is well suited to allow mass production of first and second members 14, 12 for use in the joint assembly 16. In a particular example, both the first and second members may be machined from a single piece of panel board, which may minimize material wastage and may improve ease of manufacture in many use cases. FIGS. 3a and 3b show the first and second members 14, 12 immediately after they have been machined from a single piece of panel board, as described.

(29) Instructions (or a program) for manufacturing the first and/or second members may be saved into machine code which is useable by CNC machines. The use of such machine code instructions may allow for easy manufacturing—a CNC machine loaded with the instructions and having suitable material may manufacture both the first and second member based on a single user input. Where such a program is provided, it may include consideration of the materials and tools available and modify the dimensions and tolerances of the joint appropriately. Such a program may be stored on a server, a hard drive, or a USB stick and may be transferred between systems using an area network, such as the internet.

(30) The dimensions of the material used may vary according to the particular use case of the joint assembly 16. At a minimum, the material of the second member 12 should be no less thick than 9 mm to ensure adequate strength. The joint assembly 16 works as a corner joint in material of a thickness of a 18 mm or above, in particular where the material is edgebanded MFC.

(31) In a particular use case, a plurality of joint assemblies 16 are used to assemble a furniture item which “locks together” to form a complete linkage, in such a way that no additional fixings are required. A shelving unit may be a particularly useful application of such a furniture item formed without additional fixings.

(32) FIG. 4a shows the first member 14 resting in the second groove 32 of the second member in an “unassembled” position (i.e. the position shown in FIG. 2a). FIG. 4b shows the first and second members 14, 12 in an assembled position, once the first member 14 has been moved relative to the second member 12 to slot the tongue 22 into the second groove 32 and the lip 34 into the first groove 24.

(33) In an alternative, different materials to the described panelboard materials are used. For example, the joint assembly 16 may be implemented in solid timber, in particular a hardwood. Wood which ages and shrinks, such as unseasoned oak, may form a particularly strong (albeit irreversible) connection using the described joint assembly 16. As a further example, an alternative material that shrinks upon heating or upon drying may be used, where this may achieve a tighter fit after the members are joined. More specifically, in some embodiments the tongue 22 comprises a material that is shrinkable. In a further alternative, non-wood based materials may be used.

(34) In an alternative, the first groove 24 may be stopped in each wider portion 22a of the tongue 22, so as to ensure that the lip 34 can cannot be pushed all the way through the first groove 24 and into another crenellation 29.

(35) It will be understood that the present disclosure has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.

(36) Reference numerals appearing in the claims are by way of illustration only and shall have no limiting effect on the scope of the claims.