FURNITURE LEG

Abstract: A furniture leg assembly comprises a central strut (9) and top (7) and bottom (5) members at the ends of the central strut. A plurality of inclined tension members (10) link the top and bottom members, the location (30, 31) of the points of connection of the tension members to the top and bottom defining a plurality of truncated or complete triangles forming an array extending in circumferential fashion around the longitudinal axis of the central strut. Means (14, 15, 16, 17, 18, 19, 20, 21, 22) for stressing the assembly are provided so as to tension the tension members (10) and compress the central strut (9), the assembly when stressed forming a rigid load bearing space frame that will resist tilting and/or rotation of the top member relative to the bottom.

Description: DESCRIPTION FURNITURE LEG . The present invention relates to legs for items of furniture such as tables, stools, chairs etc. and, more particularly, to a furniture leg which may, if desired, provide single, pedestal, support for an item of furniture. Circular or square tables having a single, central, pedestal support with a plurality of legs extending from the bottom of the support and spreading to form a foot or base for the table have been made for very many years. However, the means of fixing of the table top to the pedestal is potentially weak and frequently allows a degree of deflection and torsional movement , of the table top both of which are undesirable. In order to overcome these problems the join between the pedestal and the table top has been strengthened by providing a top frame which is connected to the leg by bracing supports, but this, of course, increases the weight of the table and is unattractive as it makes it bulky and cumbersome in appearance. Much modern furniture now utilises metal frameworks, legs etc. by means of which the traditional bulkiness of wooden furniture designs can, at least partially, be overcome. Increasingly, there is a need for so-called knock-down furniture which can be sold in disassembled form for assembly by the purchaser. However, making pedestal tables and the like in knock-down form inevitably means that the joints between the top of the pedestal and the table top will not be as firm as is really desirable. There is a need therefore for a furniture leg, which may be used as a pedestal leg for a table or the like, which is both sufficiently rigid to prevent significant deflection of the table top relative to the floor, which is torsionally rigid, which may enable self-assembly from knock-down form, and which is not excessibly bulky and therefore unaesthetic. According to the present invention therefore a furniture leg assembly comprises a central strut; top and bottom members at the ends of the central strut; a plurality of inclined tension members linking the top and bottom members, the location of the points of connection of the tension members to the top and bottom defining a plurality of truncated or complete triangles forming an array extending in circumferential fashion around the longitudinal axis of the central strut; and means for stressing the assembly so as to tension the tension members and compress the central strut, the assembly when stressed forming a rigid load bearing space frame that will resist tilting and/or rotation of the top member relative to the bottom. The tension members are preferably cables, wires or thin rods. No rigidity is assumed or required between the top and bottom members and the central strut other than as provided by the tension members. The central strut may comprise two or more sections pivotally or otherwise joined to one another, the joins between the strut portions being connected to the tension members to prevent sideways displacement. In such cases, the assembly will also comprise plural means for stressing the central strut. The space frame formed by the inclination of the tension members around the central axis provides torsional stiffness to the assembly and prevents any significant rotation between the top and bottom members. The inclined members and the central strut locate the top member at a fixed distance from the bottom member and hold it firmly to prevent tilting. Preferably, the top and bottom members are star shaped rigid assemblies or are extended to form a polygonal, oval or circular table top and/or base or formed by branching of the central strut at top and bottom, the branches being held in relative position by further tension members extending between them. If the top member is a rigid star or is branched, the table top may rest upon it, for example, in the case of a heavy glass plate, or may be fixed to it, for example, in the case of a stool seat. Examples of furniture leg assemblies constructed in accordance with the present invention will now be described with reference to the accompanying drawings in which:- Figure 1 illustrates a simple form of the leg providing pedestal support for a table; Figure 2 illustrates a more complex structure fulfilling the same function; Figure 3 is a third structure fulfilling the same function; Figure 4 is a cross-sectional view of the attachment of the central strut to the top member of the examples shown in Figures 1 and 2; Figure 5 is a cross-sectional view of the attachment of the central strut to the bottom member; Figure 6 is a diagrammatic view of the wire assembly of the example shown in Figure 2; Figure 7 shows attachment means for the wire assembly shown in Figure 6; Figure 8 is an exploded view of the attachment of the tension members to the top and bottom members; Figure 9 is a side view of the attachment shown in Figure 8; and Figure 10 is an end view of the attachment shown in Figure 8. Figure 1 is a diagrammatic perspective view of a table 1 having a table top 2, a base 3 and a supporting leg assembly 4. The base 3 which, for example, may be formed from wood, metal or rigid synthetic plastics material, also forms the bottom member of the leg assembly 4 and, in the example shown, comprises three arms 5 each carrying a pad-like foot 6 and being equi-angularly spaced apart. Under the table top 2, and connected or connectable to it, a top member 7, also formed by three radially extending arms 8, is positioned, the arms 8 being offset from the arms 5 by 60° so as to lie substantially centrally between adjacent pairs of the arms 5. A central strut 9, again of timber, metal, synthetic plastics or the like connects with the upper and lower members 7, 3 respectively, the connection with the upper member being a simple spigot and socket type connection and the connection with the bottom member 3 being a screw-threaded connection allowing screw-threaded displacement of the strut 9 relative to the base 3 as described below. Tension members 10 in the form of slender wires (though rods may be used) extend in continuous fashion between the arms 5 of the base 3 and the corresponding arms 8 of the top member 7 in a circumferential fashion around the central strut 9, the wires being fixed as described below at their points of location on the top and bottom members so that the triangulated space frames, effectively formed by the wires, sustain their shape in use. Figure 2 shows a more complex structure in which the central strut is provided by two strut portions 9' connected with a hub portion 11 of an intermediate member 12 which includes additional arms 13. The arms 13 connect the hub 11, and thus the central strut, at the junction between its two portions 9', with the tension wires 10 between the top and bottom of the leg assembly. When assembled, the corners of the triangular wire assemblies are fixed to the top and bottom members, i.e., the wires are not free to move to vary the length of the sides of the triangles. The bottom member 3', the top member 7' and the intermediate member 12 are all in the shape of regular, 6-pointed stars, the arms 8' of the top member being directly above the arms 5' of the bottom member, and the arms 13 being offset from the arms 8 1 , 5* by 60° so as to lie substantially centrally between respective adjacent pairs of the arms 8', 5'. The arms 13 may be replaced by additional tension wires or rods if desired. Furthermore, the strut 9 may be separated into multiple sections, each of the joins therebetween being connected into the space frame assembly of the tension wires or rods by additional members, in order to maintain the structural integrity of the assembly. An example of this type of structure is shown in Figure 3, wherein the central strut is in three portions 90, 91, 92. The bottom 91 and the top 92 portions are substantially the same length, whilst the middle portion 90 is somewhat shorter. Wires 100 fulfill the function served by the arms 13 previously described with reference to Figure 2. Ideally, the wires 100 are spaced such that the lengths a and b shown are equal; similarly ideally, the wires 10 are spaced such that the lengths c and d are equal. This is facilitated by having screw-threaded connections between the central strut and the top member as well as between the central strut and the bottom member. Figure 4 shows a cross-sectional view of the attachment of the central strut 9, 9' to the top member 7, 7 1 of the examples described with reference to Figures 1 and 2 (hereinafter, for simplicity. unprimed reference numerals only will be used) . The central strut 9 has a tapered section 14 which engages a socket 15. The top member 7 is provided with a centrally positioned recess 16 shaped so as to receive the socket 15. Rotation of the central strut 9 about its longitudinal axis is allowed due to the sliding engagement between the section 14 and the socket 15. Figure 5 is a cross-sectional view of the attachment of the central strut 9 to the bottom member 3 of the examples shown in Figures 1, 2 and 3 r a similar attachment being used between the central strut and the top member of the Figure 3 example. The central strut 9 has a tapered portion 17 which engages a socket portion 18, which is substantially disc shaped and is provided with a screw thread 19 on its outer circumferential surface. The bottom member 3 has a centrally positioned cylindrical bore 20 in which is rigidly fixed an insert 21, which has a screw-threaded bore 22 therethrough. The socket portion can be rotated about its longitudinal axis so that the screw engagement between it and the screw-threaded bore 22 causes vertical displacement of the central strut 9. Rotation thus tensions the wires 10 to the desired degree (at the same time putting the central strut 9 into compression) , whereafter the arrangement of and the tensions in the wires serves to maintain the leg and thus the table in a substantially rigid assembly, preventing relative rotation between the table top and the base and at the same time substantially preventing tilting of the top relative to the floor. The bottom thread may be replaced by a separate bolt threaded into the bottom member and thrusting against the strut. In the example shown in Figure 3, the top portion 92 of the central strut is also rotated so as to equalise the lengths a and b, and c and d. increasing the rigidity and stability of the structure. The wire assembly of the example described with reference to Figure 2 is shown diagrammatically in Figure 6, the wire retaining system being shown in Figure 7. A wire retaining system 23 is attached to the free end of each of the six arms 13 of the intermediate member 12. Each wire retaining system 23 comprises a stainless steel ring 24, which has its plane substantially vertical in use; and a further three stainless steel rings 25, 26, each of which is slotted so that it is able to be slidably fitted over the ring 24 as shown in Figure 7. Each ring 25, 26 is provided with a groove 29,27 around its circumference which is shaped so as to receive a tension wire 10,28. The tension wire 28 takes the form of a loop in the shape of regular hexagon which has its plane horizontal. Two continuous wire loops 10 are provided, one for the upper portion, this being attached at a point 30 to the top member 7', and a lower portion, this being attached at a point 31 to the bottom member 3'. To form the loops, the two ends of each wire 10, 28 are connected to one another by simple wire connecting means 32. The means for attaching the wires 10 to the top and bottom members is shown in Figures 8, 9 and 10. At the free end of each arm 3, 3 1 , 8, 8* there is a recess 33 in which is positioned a tubular member 34 which has conically diverging ends 35. A mounting block 40 comprises two portions 41, 42 each of which has a recess 43 shaped so that the mounting block 40 fits snugly over the arm 3, 8. Each portion 41, 42 has an aperture therethrough which receives a cylindrical pin 44 snugly fitted therein. The pin 44 has a groove 45 centrally positioned and passing around its circumference. In use, the wire 10 passes through the tubular member 34, between the portions 41, 42 of the mounting block 40, over the cylindrical supporting member 44, lying in the groove 45, and back through the tubular member 34. Tensioning of the wires 10 by rotation of the central strut socket 18 pulls the mounting block 40 firmly onto the arm 3, 8. Small rubber pads 46 are provided on the upper surfaces of the portions 41, 42 which in use are attached to the upper member 7, these rubber pads 46 providing a support for a table top. As will be readily apparent from the above, the component parts of the table may be provided in knock-down, user-assemblable kit form requiring merely assembly of the wires or rods to the upper and lower members, insertion of the central strut, and subsequent tensioning of the wires in order to assemble the table leg, whereafter the table top may be located on the top arms 8,8'. A larger table may, of course, have two or more legs constructed in this manner.

Claims: CLAIMS 1. A furniture leg assembly comprising a central strut; top and bottom members at the ends of the central strut; a plurality of- inclined tension members linking the top and bottom members, the location of the points of connection of the tension members to the top and bottom defining a plurality of truncated or complete triangles forming an array extending in circumferential fashion around the longitudinal axis of the central strut; and means for stressing the assembly so as to tension the tension members and compress the central strut, the assembly when stressed forming a rigid load bearing space frame that will resist tilting and/or rotation of the top member relative to the bottom. 2. An assembly according to claim 1, wherein the tension members are cables or wires. 3. An assembly according to claim 1, wherein the tension members are rods. 4. An assembly according to any of claims 1 to 3, wherein the central strut comprises two or more sections pivotally or otherwise joined to one another, the joins between the strut portions being connected to the tension members to prevent sideways displacement. 5. An assembly according to any of claims 1 to 4, wherein the top and bottom members are star shaped rigid assemblies. 6. An assembly according to claim 2, wherein the cables or wires are each in the form of a continuous loop. 7. A table having at least one furniture leg assembly according to any of claims 1 to 6, and a table top positionable thereon. 8. A furniture leg substantially as described with reference to any of the examples shown in the accompanying drawings.

Inventors: PRYKE JOHN FORDHAM SPEAIGHT, PRYKE NICHOLAS JOHN SPEAIGHT, PRYKE, JOHN, FORDHAM, SPEAIGHT, PRYKE, NICHOLAS, JOHN, SPEAIGHT
Applicants: PRYKE JOHN FORDHAM SPEAIGHT, PRYKE NICHOLAS JOHN SPEAIGHT, PRYKE, JOHN, FORDHAM, SPEAIGHT, PRYKE, NICHOLAS, JOHN, SPEAIGHT
Application year: 1988
Main classification: A47B3
IPC codes: A47B3, A47B91