WO2009128096A1

WO2009128096A1 - A corner bracket and a frame comrprising the corner bracket

Info

Publication number: WO2009128096A1
Application number: PCT/IT2008/000245
Authority: WO
Inventors: Diano Tura
Original assignee: Flexfor S.R.L.
Priority date: 2008-04-14
Filing date: 2008-04-14
Publication date: 2009-10-22
Also published as: WO2009128096A8

Abstract

A corner bracket for connecting two members comprises : a first and a second perimetric portion (21, 22), mutually converging, meeting at a shared area (20) and defining a first space (2) interposed between them; means (3) for fastening the corner bracket to the two members, said fastening means (3) comprising at least one protrusion (30) extending in a direction away from the first space (2) between a first end (201) proximal to the first space (2) and a second end (202) distal to the first space (2); at least one section of the protrusion (30) comprises a flare (32) which extends for a first length (Ll) between a root of it (321) proximal to the first end (201) and an end portion of it (322) distal to the first end (201). The flare (32) widens from the root (321) to the end portion (322). A distance (L2) between the second end (202) of the protrusion (30) and the end portion (322) of the flare (32) is smaller than the first length (Ll) of the flare (32).

Description

A corner bracket and a frame comprising the corner bracket

Technical Field

This invention relates to a corner bracket for connecting two members, typically a corner bracket connecting two longitudinal members forming part of a mattress frame for supporting the human body. The invention is therefore applicable to beds or sofas.

Background Art

Beds are known which comprise four separate longitudinal members or side rails mutually arranged to form a rectangle that perimetrically delimits an area designed to receive the mattress. At each of the four corners of the rectangle, two consecutive side rails are connected by a corner bracket. The corner bracket comprises a structure having the shape of a right-angled triangle. From each of the two legs of the right-angled triangle extends a protrusion that is slotted into a matching socket made in the respective side rail. The protrusion is shaped like a right-angled solid that extends between two bases between which there is an interposed lateral surface. When the protrusion is inserted into its socket, the generator of the lateral surface lies vertically and the two bases are positioned horizontally. A generic section of the right-angled solid drawn at right angles to the generator forms a circle without a first portion. The first portion is defined by the interposed surface between a base chord and the circumference of the circle. At the base chord of each generic section, the solid is connected to the remaining parts of the corner bracket. In particular, the generic section has a diameter that extends parallel to the principal direction of the side rail into which the protrusion is slotted. The socket in the side rail is substantially shaped to match the shape of the protrusion it is designed to receive.

To remove the protrusion from the socket, the side rail must be pulled off vertically relative to the corner bracket . These beds are not free of disadvantages, however. In particular, the function of the corner brackets is to make the bed stable by connecting the side rails to each other firmly and preventing them from coming apart . This is made possible mainly by the contact between the socket for the protrusion and the lateral surface of the protrusion from the line where it joins the corner bracket to the diameter extending parallel to the principal direction of the side rail. During use, the high stresses created by the torque acting on the side rail are opposed by the small portion of the corner bracket socket wedged between the line where the protrusion joins the corner bracket and the diameter of the protrusion parallel to the longitudinal member. The parts of the socket that come into contact with the lateral surface of the protrusion have practically no effect in opposing these stresses. These remaining parts of the lateral surface of the protrusion, ^• however, make it necessary for the side rail to be made thick enough to accommodate the entire protrusion of the corner bracket.

Disclosure of the Invention This invention has for an aim to overcome the above mentioned disadvantages by providing a corner bracket for connecting two members that improves the structural resistance of the frame it forms part of .

Another aim of the invention is to overcome the above mentioned disadvantages by providing a device for connecting two members that allows the two elements to be shaped with the utmost freedom.

These aims and others, which shall become more readily apparent in the course of the description that follows, are achieved, in accordance with this invention by a corner bracket for connecting two members and having the structural and functional features described in the accompanying independent claims, other embodiments of the invention being defined in the accompanying dependent claims .

Brief Description of the Drawings

The invention will now be described in more detail with reference to the accompanying drawings, which illustrate a non- limiting preferred embodiment of it .

- Figure 1 is a perspective view of a corner bracket according to the invention. - Figures 2 , 3 and 4 are three orthogonal views of a corner bracket according to the invention.

- Figure 5 shows a portion of a frame according to the invention .

- Figures 6 and 7 are partially exploded views of the frame portion of Figure 5.

Detailed Description of the Preferred Embodiments of the Invention

The reference numeral 1 in the accompanying drawings denotes a corner bracket for connecting two members, in particular a corner bracket connecting two longitudinal members 10a, 10b extending mainly lengthways. The corner bracket 1 comprises first and second mutually converging perimetric portions 21, 22 meeting at a shared area 20 and defining a first space 2 interposed between them. The corner bracket 1 comprises means 3 for fastening the corner bracket to the two members 10a, 10b. The fastening means 3 comprise at least one protrusion 30 extending in a direction away from the first space 2 between a first end 201 proximal to the first space 2 and a second end 202 distal to the first space 2. At least one section of the protrusion 30 comprises a flare 32. The flare 32 extends for a first length Ll between a root of it 321 proximal to the first end 201 and an end portion of it 322 distal to the first end 201. The flare 32 widens from the root 321 to the end portion 322. A distance L2 separating the second end 202 of the protrusion 30 from the end portion 322 of the flare 32 is smaller than the first length Ll of the flare 32. Obviously, the distance L2 might also be zero (in which case the second end 202 of the protrusion 30 would coincide with the end portion 322 of the flare 32) .

Advantageously, the flare 32 comprises converging sides 32a, 32b that make an angle of between 10° and 40°, preferably between 20° and 30°.

In a first embodiment that is not illustrated, the flare 32 terminates at the second end 202 of the protrusion 30 (in which case the distance L2 is zero) . Alternatively (as in the embodiment illustrated) the protrusion 30 comprises an additional interposed portion 8 between the second end 202 and the end portion 322 of the flare 32. Said additional portion 8 extends along the extension of the flare 32 for the distance L2. The additional portion 8 is made as a single part with the flare 32. Advantageously, the distance L2 is less than or equal to half the first length Ll. Preferably, the distance L2 is less than or equal to a third of the first length Ll. With reference to the accompanying drawings, the second end 202 of the protrusion 30 has bevelled or rounded edges 80 connecting it to the end portion 322 of the flare 32. Thus, the absence of sharp edges prevents it from jamming against the sides of the socket 11 when the protrusion 30 is inserted into the socket 11 (the socket 11 is made in the members 10a, 10b) .

Obviously, the longer the protrusion 30 is, the thicker the longitudinal member 10a, 10b must be to accommodate it during use. Thus, if a protrusion 30 is provided, at least the end part of it should be flared, becoming wider away from the first space 2. This increases the surface of the protrusion 30 that cooperates with its socket 11 to oppose the force tending to pull the protrusion 30 out of the socket 11 in the direction joining the first and the second ends 201, 202 (as indicated by the arrow labelled "F" in Figure 3) . On the other hand, if the protrusion 30 includes an additional portion 8 that is not flared so that it does not become wider away from the first space 2 (for example, to facilitate insertion into its slot 11, as described in more detail above) the additional portion 8 should be limited in size.

If this were not the case, the end of the protrusion 30 would not contribute to improving the connection and would only make it necessary to increase the size of the slot 11 to accommodate the protrusion 30 (thus also making it necessary to increase the size of the member in which the slot 11 is made) .

Advantageously, the fastening means 3 comprise a plurality of protrusions 30.

The plurality of protrusions 30 comprises a first set 30a of protrusions 30 made on the first perimetric portion 21 and/or a second set 30b of protrusions 30 made on the second perimetric portion 22.

Advantageously, the corner bracket 1 comprises a wall 4 that extends along the first and/or the second perimetric portion 21, 22 and at least partly delimits the first space 2. As shown in the drawings, the protrusion/each protrusion 30 extends from the wall 4. Advantageously, the wall 4 comprises a first part 41 that extends along the first perimetric portion 21. The wall 4 may also comprise a second part 42 that extends along the second perimetric portion 22. The first part 41 of the wall 4 lies in one plane; the second part 42 of the wall 4 lies in one plane. Advantageously, the first and second parts 41, 42 of the wall 4 are mutually convergent and make an interposed angle greater than 85° and less than 90°, preferably greater than 87° and less than 90°, and, in particular, equal to 88.5°. Advantageously, the wall 4, during use, is designed to come into contact with the longitudinal members 10a, 10b. Preferably, contact occurs along substantially the full length of the wall 4. As explained in more detail below, this avoids the risk that slats connected to the longitudinal members 10a, 10b may fall. Normally, beds or bed bases comprise a frame composed of four longitudinal members connected at their ends by respective corner brackets 1 to form a rectangular structure. A plurality of slats extend between two opposite (non- consecutive) longitudinal members and^' the mattress is placed on the slats . The slats have a predetermined length covering the space between the two longitudinal members they are connected to . The slats are normally slotted into appropriate grooves made in the two longitudinal members between which the slats themselves extend. The Applicant has found that the longitudinal members are not always perfectly straight but are slightly humped towards the outside of the frame (probably on account of the methods used to make the longitudinal members themselves) . When this is the case, the slats may fall out of the grooves onto the floor. With an angle slightly less than 90° between the first and the second parts 41, 42 of the wall 4, pressure is exerted on the ends of the longitudinal members in such a way as to straighten them and prevent the slats from falling.

As illustrated by way of example, the first and the second portion 21, 22 comprise a flat tab 5 extending away from the first space 2. In use, the longitudinal members 10a, 10b rest on the tabs 5.

The protrusion/each protrusion 30 comprises:

- a first base 301; - a second base 302 opposite the first base 301;

- a lateral surface 303 extending between the first and the second base 301, 302 and defining the flare 32.

As illustrated by way of example in Figure 1, the first base 301, the second base 302 and the lateral surface 303 are interposed between the first and the second end 201, 202 of the protrusion 30.

The protrusion/each protrusion 30 advantageously extends from the flat tab 5.

In particular, the first base 301 of the protrusion 30 acts as an interface between the protrusion 30 and the flat tab 5.

In a plane parallel to the tab 5, the section of the flare 32 is trapezoidal. Advantageously, the section of the flare 32 is substantially in the shape of an isosceles trapezium whose minor base is closer to the wall 4 than its major base. In an embodiment that is not illustrated, the first length Ll of the flare 32 might vary between the first and the second base 301, 302; in this case, the above mentioned relations between the first length Ll and the distance L2 would occur, for example, in a plane (preferably parallel to the tab 4 and passing through the flare 32) . In the preferred embodiment illustrated, the first length Ll of the flare 32 is constant between the first and the second base 301, 302.

Figure 3 shows the first length Ll and the distance L2 for a protrusion 30. In the case illustrated, the first length Ll and the distance L2 are measured at right angles to the wall 4 at the point where the protrusion 30 extends from the wall 4.

The protrusion/each protrusion 30 comprises longitudinal ridges 33 formed on the lateral surface 303.

The ridges 33 extend in a straight line in a direction joining the first and second bases 301, 302.

Alternatively (in an embodiment not illustrated) the ridges 33 might extend along the lateral surface 303 away from the root of the flare.

Advantageously, the cross section of the ridges 33 has the shape of a right-angled triangle, a first leg of which rests on the lateral surface 303 and a second leg of which faces the flat tab 5. Thus, the hypotenuse of the ridges 33 constitutes a guide for the insertion of the longitudinal member, while the second leg constitutes an element for securing the corner bracket 1 to the longitudinal member.

Advantageously, the ridges 33 make it possible to compensate for slack created by imprecise machining of a protrusion 30 or slot 11 that accommodates the protrusion; for example, the ridges

33 could compensate for shrinkage of the corner bracket material immediately after being moulded.

In at least two protrusions 30 of the first set 30a or at least two protrusions 30 of the second set 30b the distance between the first and the second base 301, 302 differs.

As illustrated by way of non-limiting example in the accompanying drawings, the protrusion/each protrusion 30 has a "dovetail" shape. The protrusion/each protrusion 30 comprises a collar 6 between the first end 201 and the flare 32.

The collar 6 is very important to guarantee machining precision. In fact, the slots 11 of the protrusions 30 are normally made using a tapered bit where the taper has a predetermined height. The slots 11 are made by simply inserting and extracting the bit from the longitudinal member, moving in a single predetermined direction. If slots 11 were made without the additional groove to accommodate the collar 6 , even the smallest error in positioning the bit would result in slots 11 of different sizes. In particular, the inlet opening of the slots 11 would differ considerably according to the height of the bit that actually cuts the longitudinal member. The collar 6 on the protrusions 30, on the other hand, guarantees the constant size of the slots 11. It is thus possible to first make a groove in the longitudinal member and then position the bit in such way that, during machining of the longitudinal member, the untoothed shank of the bit goes into the groove. As a result, the bit cuts the longitudinal member for the full height of the truncated cone so as to guarantee that the impression made by the bit on the longitudinal member is constant in size.

In at least two protrusions 30 of the first set 30a or at least two protrusions 30 of the second set 30b the collar 6 differs in height. The height of the collar 6 is measured along a line joining the first end 201 of the protrusion 30 to the root 321 of the flare 32.

This is very important because, in a typical application, the corner bracket is used to join two longitudinal members 10a, 10b comprising a plurality of flat, parallel, superposed layers of wood. Each of these layers is just a few millimetres thick. The different height of the collar 6 improves stress distribution in the different, superposed wood layers and hence reduces the risk of reaching stresses that can break the longitudinal member. When the longitudinal member is connected to the corner bracket, the wood layers are arranged in such a way that their thickness extends along the line joining the first and the second end 201, 202 of the protrusion 30 (that is to say, in such a way that they are substantially parallel to the first or the second part 41, 42 of the wall 4 of the corner bracket 1 or, similarly, extend in a plane transversal to the line joining the first and the second end 201, 202 of the protrusion 30) . That is because the different height of the collars 6 of two protrusions 30 enables the flare 32 of the first protrusion 30 to interact with a wood layer that is not affected by the flare 32 of the second protrusion 30 (for constructional simplicity of the corner bracket 1 and of the slots into which the protrusion 30 will be inserted, all the flares 32 should extend between the first and second ends 201, 202 of the protrusion 30 for the same length) . Similarly, the flare 32 of the second protrusion 30 may interact with a wood layer not affected by the flare 32 of the first protrusion 30. The protrusion/each protrusion 30 comprises an internal lightening hole 7.

In the shared area 20 of the first and second perimetric portions 21, 22, the fastening means 3 include an end protuberance 24 comprising securing means 25.

The securing means 25 comprise a first and a second tooth 251, 252 positioned symmetrically. The first tooth 251 faces the first set 30a of protrusions 30. The second tooth 252 faces the second set 30b of protrusions 30. The first tooth 251 is located on the outside of a bundle of lines running parallel to the first part 41 of the wall 4 for each point of the flare 32 of each protrusion 30 of the first set 30a. Similarly, the second tooth 252 is located on the outside of a bundle of lines running parallel to the second part 42 of the wall 4 for each point of the flare 32 of each protrusion 30 of the second set 30b. This improves stress distribution since the first and/or the second tooth 251, 252 can also interact with different wood layers not affected by the flares 32.

The corner bracket 1 comprises a plurality of reinforcement ribs 23 connecting the first and the second perimetric portion 21, 22 and running across the first space 2.

The first space 2 has formed in it a housing 200 designed to accommodate a screw whose head is shaped to match the housing 200 itself (for example a hex head screw) . The threaded part of the screw extends downwards with respect to the corner bracket 1. Once it has been inserted into its housing, the screw cannot rotate about its principal axis of extension. It is then screwed into a hole made in a leg that supports the frame. Thus, assembly is extremely quick and does not require any special tool . Figures 6 and 7 show a corner cap 240 that fits onto the end protuberance 24.

Advantageously, the first and second perimetric portions 21, 22 of the corner bracket 1 and the protrusion 30 extending from them are made as a single part . The corner bracket 1 has a substantially triangular shape, preferably the shape of a right-angled triangle. The first and second perimetric portions 21, 22 form part of the legs of the right-angled triangle shaped corner bracket 1.

Advantageously, at least the first and the second perimetric portions 21, 22 and the protrusion 30 extending from them are made by die casting. Further, the first and the second perimetric portions 21, 22 and the protrusions 30 extending from them are made preferably, but not necessarily, of glass charged nylon.

This invention also provides a supporting frame for cushions or mattresses that support the human body, comprising:

- at least two longitudinal members 10a, 10b placed transversely to each other (these longitudinal members being usually referred to as "side rails" in the jargon of the trade);

- a corner bracket of the type described above.

Each longitudinal member 10a, 10b comprises at least one slot 11 to house the corresponding protrusion 30 of the corner bracket 2 of the connecting device 1.

The at least one slot 11 and the corresponding protrusion 30 are shaped to match each other.

In one particular embodiment, the protrusion 30 is fitted into the corresponding socket 11 by interference. The longitudinal members 10a, 10b are normally made of wood. Preferably, they comprise a plurality of layers extending in the same principal direction as the longitudinal member itself.

The supporting frame of the above mentioned type is used for beds or sofas. Normally, the frame 2 comprises four longitudinal members connected at their ends to form a quadrilateral, advantageously a rectangle .

Normally, in use, a protrusion 30 made on the first perimetric portion 21 of the corner bracket 1 and a protrusion 30 made on the second perimetric portion 22 of the corner bracket 1 are fitted into two respective slots made in two respective longitudinal members of the frame. Advantageously, the protrusions 30 are fitted into the slots in a direction at right angles to the frame supporting plane (usually coinciding with the floor) . In this way, at least two longitudinal members are connected to each other. The operation is then repeated to connect the other longitudinal members to each other. The invention brings important advantages .

First of all, the corner bracket according to the invention improves the distribution of the stresses created between the protrusions and the respective slots into which they are fitted. Another important advantage is that the corner bracket makes it possible to reduce the thickness of the longitudinal member in which the slot for accommodating the protrusion is made.

The invention can be modified and adapted in several ways without thereby departing from the scope of the inventive concept. Moreover, all the details of the invention may be substituted by technically equivalent elements.

In practice, the embodiments of the invention may be made from any material, and in any size, depending on requirements.

Claims

1. A corner bracket for connecting two members comprising:

- a first and a second perimetric portion (21, 22), mutually converging, meeting at a shared area (20) and defining a first space (2) interposed between them;

- means (3) for fastening the corner bracket to the two members, said fastening means (3) comprising at least one protrusion (30) extending in a direction away from the first space (2) between a first end (201) proximal to the first space (2) and a second end (202) distal to the first space (2); at least one section of the protrusion (30) comprising a flare (32) which extends for a first length (Ll) between a root of it (321) proximal to the first end (201) and an end portion of it (322) distal to the first end (201) , the flare (32) becoming wider from the root (321) to the end portion (322); characterized in that a distance (L>2) between the second end (202) of the protrusion (30) and the end portion (322) of the flare (32) is smaller than the first length (Ll) of the flare (32) .

2. The corner bracket according to claim 1, characterized in that the distance (L2) between the second end (202) of the protrusion (30) and the end portion (322) of the flare (32) is less than half the first length (Ll) .

3. The corner bracket according to claim 1 or 2 , characterized in that the distance (L2) between the second end (202) of the protrusion (30) and the end portion (322) of the flare (32) is zero.

4. The corner bracket according to claim 1 or 2 or 3 , characterized in that the flare (32) comprises converging sides (32a, 32b) that make an angle of between 10° and 40°.

5. The corner bracket according to any of the foregoing claims, characterized in that the fastening means (3) comprise a plurality of protrusions (30) .

6. The corner bracket according to claim 5 , characterized in that the plurality of protrusions (30) comprises a first set (30a) of protrusions (30) made on the first perimetric portion (21) and/or a second set (30b) of protrusions (30) made on the second perimetric portion (22) .

7. The corner bracket according to any of the foregoing claims, characterized in that it comprises a wall (4) that extends along the first and/or the second perimetric portion (21, 22) and at least partly delimits the first space (2), the protrusion/each protrusion (30) extending from said wall (4) .

8. The corner bracket according to claim 7, characterized in that the wall (4) comprises a first part (41) that extends along the first perimetric portion (21) and a second part (42) that extends along the second perimetric portion (22) , the first and second parts (41, 42) of the wall (4) being mutually convergent and making an interposed angle greater than 85° and less than 90°.

9. The corner bracket according to any of the foregoing claims, characterized in that the first and second portions (21, 22) each comprise a flat tab (5) which extends away from the first space (2) and from which the protrusion/each protrusion (30) extends.

10. The corner bracket according to any of the foregoing claims, characterized in that the protrusion/each protrusion (30) comprises : - a first base (301) ;

- a second base (302) opposite the first base (301);

- a lateral surface (303) extending between the first and second bases (301, 302) and defining the flare (32) ; the first base (301), the second base (302) and the lateral surface (303) being interposed between the first and the second ends (201, 202) .

11. The corner bracket according to claim 10 when it depends on claim 9, characterized in that the first base (301) is in contact with the flat tab (5) .

12. The corner bracket according to claim 10 or 11, characterized in that the protrusion/each protrusion (30) comprises longitudinal ridges (33) formed on the lateral surface (303) .

13. The corner bracket according to claim 12 , characterized in that the ridges (33) extend in a straight line in a direction joining the first and second bases (301, 302) .

14. The corner bracket according to any of the foregoing claims from 10 to 13 when dependent directly or indirectly on claim 6, characterized in that in at least two protrusions (30) of the first set (30a) or at least two protrusions (30) of the second set (30b) the distance between the first and the second base (301, 302) differs.

15. The corner bracket according to any of the foregoing claims, characterized in that the protrusion/each protrusion (30) has a "dovetail" shape.

16. The corner bracket according to any of the foregoing claims, characterized in that the protrusion/each protrusion (30) comprises a collar (6) between the first end (201) and the flare (32) .

17. The corner bracket according to claim 16 when dependent directly or indirectly on claim 6, characterized in that in at least two protrusions (30) of the first set (30a) or at least two protrusions (30) of the second set (30b) , the collars (6) differ in height .

18. The corner bracket according to any of the foregoing claims, characterized in that the protrusion/each protrusion (30) comprises an internal lightening hole (7) .

19. The corner bracket according to any of the foregoing claims, characterized in that in the shared area (20) of the first and second perimetric portions (21, 22) , the fastening means (3) include an end protuberance (24) comprising securing means (25) .

20. The corner bracket according to any of the foregoing claims, characterized in that the corner bracket (2) comprises a plurality of reinforcement ribs (23) connecting the first and the second perimetric portions (21, 22) and running across the first space (2) .

21. A supporting frame for cushions or mattresses that support the human body, comprising:

- at least two longitudinal members (10a, 10b) placed transversely to each other;

- a corner bracket according to any of the foregoing claims from 1 to 20, each longitudinal member (10a, 10b) comprising at least one socket (11) that houses the corresponding protrusion (30) of the corner bracket (1) .

22. The frame according to claim 21, characterized in that the at least one slot (11) and the corresponding protrusion (30) are substantially shaped to match each other.

23. The frame according to claim 21 or 22, characterized in that the protrusion (30) is fitted into the corresponding socket (11) by interference .