Joint for furniture support structure

The disclosure herein describes a joint consisting of three serially-interconnectable members each including a cut-away section; the volumes defined by the cut-away sections of the first and second are equal and L-shaped. These two members, once assembled, define a cut-away section, the volume of which is rectangular. The volume of the cut-away section of the third member which serves to interlock the three pieces together equals the sum of the said L-shaped volume and the rectangular volume. One application of the joint of the present invention is in furniture support structures such as tables, shelves or the like.

FIELD OF THE INVENTION 
This invention relates generally to furniture construction and, more 
particularly, to a joint for use in the support structure of furniture, 
such as tables, shelves or the like. 
BACKGROUND OF THE INVENTION 
In most cases where it is required to provide a strong and sturdy structure 
for furniture, fasteners and/or glue are used to assemble the parts 
together. However, in some instances, the use of a fastener or glue is not 
desired for aestetics reasons; for example, the presence of a fastener may 
decrease the visual effect to be given to a piece of furniture. Also, the 
use of fasteners requires tool. In cases where glue is used, the 
disassembly of the furniture is usually not permitted or, at least, not 
recommended for fear of damaging the furniture element. 
OBJECTS AND STATEMENT OF THE INVENTION 
It is an object of the present invention to provide a joint which, in 
addition to enhance the appearance of a furniture, can be easily assembled 
and disassembled. 
It is a further object of the present invention to provide a joint which 
allows such assembly and disassembly without the use of tools. 
It is an other object of this invention to provide an interlocking joint 
which retains its qualities of ornementation and usefulness. 
The present invention is achieved by providing a joint which consists of 
three serially-interconnectable members wherein the first and second 
members are first interfitted and thereafter interlocked with the third 
member; each member has a cut-away section, each defining a specific 
volume. The volume of the first and second initially interfittable members 
is L-shaped and, once assembled, they define a cut-away section defining a 
cavity having a rectangular volume. The cut-away section of the third 
member which interlocks the three pieces together defines a cavity having 
a volume which is, at least, the sum of said L-shaped volume and said 
rectangular volume. 
In one embodiment of the invention, the cut-away section of the first 
member is a mirror image of the cut-away section of the second member. 
In another form of the invention, the L-shaped volume is a multiple of a 
basic cube; in the case where the multiple is three, the cut-away section 
on the third interlocking member has a volume in which the basic cube is 
contained five times. 
In another form of the invention, the members have, in the area of their 
cut-away section, a square cross-section, and the depth of the cut-away 
section is half the side length of this square cross-section. 
Other objects and further scope of applicability of the present invention 
will become apparent from the detailed description given hereinafter. It 
should be understood, however, that this detailed description, while 
indicating preferred embodiments of the invention, is given by way of 
illustration only, since various changes and modifications, within the 
spirit and scope of the invention, will become apparent to those skilled 
in the art. 
IN THE DRAWINGS 
FIG. 1 is a perspective view showing the first two interconnectable members 
of a three-piece joint made in accordance with the present invention; 
FIG. 2 is a perspective view of the first two members connected with the 
third member in position to interlock; 
FIG. 3 is a perspective view of the three members in interlocked engagement 
to form the joint of the present invention; 
FIGS. 4a, 4b and 4c are perspective views of the first, second and third 
members, respectively, of the joint of the present invention; and 
FIGS. 5, 6 and 7 are perspective views showing various applications of a 
joint used as in a furniture support structure.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring to FIGS. 1, 2 and 3, there are shown the three interconnectable 
members A, B, C which form the joint of the present invention. 
Referring to FIG. 1, members A and B are the two members which must 
initially be assembled with a view to forming the joint. Each member 
includes a cut-away section generally denoted 16 and 18 respectively. As 
illustrated in FIG. 4A, the cut-away section 16 is defined by a series of 
surfaces 20, 22, 24 which extend transversely of the longitudinal member 
A, of surface 26 which extends in the longitudinal direction of member A 
and of a web surface 28 which extends in the longitudinal plane of member 
A. These surfaces define an L-shaped volume. Referring to FIG. 4B, the 
cut-away section 18 is defined by a series of three surfaces 30, 32, 34 
which extend transversely of the longitudinal member B, of surface 36 
which extends in the longitudinal direction of member B, and of a web 
surface 38 which extends in the longitudinal plane of member B. These 
surfaces define an L-shaped volume. 
In the preferred embodiment illustrated, the cut-away 16 is identical in 
size and in shape to the cut-away section 18; however, one cut-away 
section is the mirror image of the other. 
FIG. 2 shows members A and B assembled. To facilitate understanding, it can 
be said that surface 36 bears against surface 24 while surface 26 bears 
against the side wall of member B, generally denoted 40, and surface 30 
bears against the bottom side wall of member A (see FIG. 1). The assembled 
members A and B leave a cut-out portion, generally denoted 42, which is 
defined by a volume of rectangular shape. 
Referring to FIG. 4(c), member C has a cut-out portion, generally denoted 
44, which defined by a series of surfaces 46, 48, 50 which extend 
transversely of the longitudinal member C, of surface 52 which extends in 
the longitudinal direction of member C and of a web surface 54 which 
extends in the longitudinal plane of member C. The volume defined by these 
surfaces is equal to that of each L-shaped volume 16, 18 of members A and 
B plus the rectangular volume 42 which is the remaining cut-out portion 
when members A and B are assembled. Referring to FIG. 2, the width between 
surfaces 46 and 48 is equal to that of member B so that once member C is 
engaged to the assembled members A and B, surfaces 46 and 48 together with 
surface 54 will slide along three sides of member B until lower edge 56 of 
member C rests on surface 42 of member A. Also, surface 52 rests on the 
side wall of member A in the area generally denoted 58. 
In one preferred form of the invention, all members A, B and C have a 
square cross-section. 
Referring to FIGS. 4a and 4b, the L-shaped volume of each cut-out section 
may be said to be formed of a multiple of a basic cube. In the case of 
cut-out sections 16, 18 this multiple is three. Referring to FIG. 4c, this 
basic cube is repeated five times. The basic cube shown in the drawings 
has a side length of X which is equal to W/2 when the members have a 
square cross-section (W being equal to the width of each side of the 
members). 
Referring to FIGS. 5, 6, and 7, there are shown various support structures 
for furniture embodying a joint made in accordance with the present 
invention is used. FIG. 5 shows a table 60 which is formed of a horizontal 
transparent top plate 62 and of the three members A, B and C. FIG. 6 shows 
the frame of a book shelf which comprises a plurality of joints formed of 
the above described members A, B and C. FIG. 7 shows a similar structure 
formed of members A, B, C for supporting a table top 64. 
Although the invention has been described above in relation to various 
forms, it will be evident to the person skilled in the art that it may be 
refined and varied in various ways. For example, the volume of the cut-out 
section of members A and B could be greater in the area away from that 
which is required to form the rectangular volume once they are assembled; 
in such case, the cross-section of the element would be rectangular rather 
than square. It is therefore wished to have it understood that the present 
invention should not be limited in interpretation except by the terms of 
the following claims.