Impact Absorbing Boss

The present invention relates to an adaptor boss for connecting first and second furniture components together. It is particularly well suited to the interconnection of tabletops with table legs and table legs with table feet, and will be predominantly described in respect of that use.

There are many different ways in which a leg may be attached to an item of furniture, and particularly a table leg may be connected to a tabletop. For instance, some table legs have a spigot upstanding from their uppermost point that locates in a recess provided on the underside of the tabletop. Such spigots are usually retained in place by means of one or more bolts. Alternatively, the recess may comprise a threaded bore and the spigot may be adapted to screw into said threaded bore.

Fixtures such as those discussed above can be problematic, particularly when used on tables having only one table leg mounted to the centre of the tabletop, since they are subject to a high level of stress. In some instances, the high level of stress is generated by loads being applied to the tabletop at a location remote from its centre, thereby creating a moment of force about the fixture. Indeed, the way in which the table leg is configured contributes to the amount of stress generated in the fixture, but the material(s) from which the fixture is made largely determines its failure point. For instance, many tables are made of glass which can be brittle.

Thus, an object of the present invention is to provide a boss for fixing a first furniture component such as a leg or foot to a second furniture component such as a top or top, which boss provides a mechanism by which loads applied thereto are to some extent dampened, thereby reducing the problems of known fixtures.

According to the present invention, there is provided a boss for connecting a first furniture component and a second furniture component and comprising a body having first and second parts adapted to engage first and second formations provided on the first and second components, and shock absorption means provided on the body and adapted to provide a cushioned interface between the first and second components.

Preferably, one of the first part and first formation comprises a female part and the other comprises a male part adapted to locate in said female part. For instance, the first formation might comprise an opening in which the first part locates. Furthermore, the first part may comprise a male part provided with shock absorption means and which is arranged to form a push fit connection with the first formation. The male and female parts may themselves be sized to form a clearance fit, but the presence of the absorption means creates a push fit.

Alternatively, the first formation may comprise a threaded recess and the first part may comprise a threaded spigot adapted to engage the threaded recess. This arrangement includes no shock absorption means and so no relative movement between the first formation and first part is permitted.

Preferably, one of the second part and second formation comprises a female part and the other comprises a male adapted to locate in said female part. Furthermore, the second part may comprise a male part on which shock absorption means are provided and which is arranged to form a push fit connection with the second formation. Thus, the first and second parts may both be arranged to form a push-fit with the first and second formations or one may be arranged to form a push fit and the other a screw fit. It is likely that greater cushioning would be provided with both first and second parts forming a push-fit, but this may adversely affect the rigidity of the connection. Furthermore, the second formation comprises a threaded recess and the second part is adapted to screw into the threaded recess. Thus, both the first and second parts could be screwed to the first and second formations, respectively, though this would produce a rigid joint. Preferably, the shock absorption means are formed from a material that will deform elastically under increased load, thereby permitting small movements between the boss and the first and second components. Most preferably the shock absorption means comprise one or more O-rings since they may provide the required deformation under load and are easy to secure to the boss. Alternatively, the shock absorption means could include sheets or studs adhered to the boss or even a deformable rubber sleeve mounted over the male part. Most preferably the shock absorption means comprise O-rings that locate in channels formed in the boss. Shock absorption means may be formed from any

suitable material, but preferably a resiliently deformable material such as natural or synthetic rubber or plastics are suitable.

In a preferred arrangement the first and second parts each have a central axis extending generally coaxially to one another, and most preferably the first and second formations and first and second parts are generally cylindrical since this would permit a greater degree of movement between the two components and also reduce the likelihood of the components jarring.

In a preferred embodiment of the invention one of the first and second parts is a male part and the other is a female part. Furthermore, the boss may be generally tubular and arranged so that the outside surface defines the male part and an inside surface defines the female part. Preferably, the tube is circular and has one end closed to define an internal end surface against which the first or second formation may bear. Additionally, shock absorption means may be provided on the outside surface defining the male part, the inside surface defining the female part and the end surfaces of the male and female part if present. This arrangement ensures that areas of the boss that are likely to interface with the first and second formations are well cushioned.

The first and second parts may have generally parallel sides such that they are of constant width. Instead one or both part may have tapering sides that are complimentary with the first and/or second formation with which they engage.

The first component may form part of a tabletop or comprise a fixture provided on a tabletop and the second component may form part of a table leg or comprise a fixture provided on a table leg. For instance, the first component may be adhered to the underside of the tabletop whereas the second component may be integral to the table leg. The present invention is also suitable for location further down, such as between a leg and a foot, or a along the length of a leg between upper and lower leg sections.

According to the present invention there is also provided an assembled table comprising a boss as described above, a table top having a first component and at least one table leg having a second component, the first part of the boss is adapted to engage a first formation provided on the first component and the second part of the boss is adapted to engage a second

- A - formation provided on the second component, at least one of the first part and the second part being adapted to form a push-fit connection with the first and second formation, respectively. Most preferably, one of the first part and the second part is adapted to form a screw fit connection with the first or second formation, respectively. The table assembly may include a plurality of legs or a single leg connected to the centre of the table top.

By way of example only, two embodiments of the present invention and certain modifications thereof will now be described in detail, reference being made to the accompanying drawings in which: Figure 1 is a cross sectional view of a first embodiment of this invention, showing a boss adapted to be connected to fixtures provided on a tabletop and a table leg;

Figure 2 corresponds to the arrangement of Figure 1 , but shows the boss connected to the fixtures; Figure 3 is an illustration of the boss shown in Figures 1 and 2;

Figure 4 is a cross sectional view of part of the boss of the first embodiment having a channel and an O-ring retained therein; and

Figure 5 is a cross sectional view of a second embodiment of this invention, showing the boss connected to fixtures provided on the tabletop and a table leg.

Figures 1 to 3 show a first embodiment of the invention in which there is provided an adaptor generally indicated 10, arranged to connect an upper fixture

11 attached to a table top (not shown) to a lower fixture 12 provided on a table leg (not shown). The adaptor 10 comprises a cylindrical body 13 having upper and lower circular end faces 14, 15 and a circumferential sidewall 16. A threaded bore 17 is formed in the centre of the lower end face 15 and which extends partway along the length of the body 13 and coaxial to the axis thereof.

Though the bore 17 extends only partway through the length of the body, for convenience it could be formed to extend the whole way through the length of the body.

O-rings 18 are seated in annular channels 20, 2OA formed in spaced- relation along the circumferential sidewall 16. Other channels 21 , 21 A are formed concentrically in the lower and upper end faces 15, 14 respectively and

O-rings 19 locate in these. The thickness of the O-rings 18, 19 is greater than the depth of the channels 20, 21 such that the O-rings project radially from the circumferential sidewall 16 and axially from the end faces 14, 15. O-rings are well known in the art, they have many characteristics including their elasticity that enables them to compress under load but return to their natural form once the load is removed.

The O-rings 18 provided on the circumferential sidewall 16 have an internal circumference equal to the circumference defined by the base of the channels 20, 2OA in which they are seated. Thus, the O-rings 18 are seated in the channels 20 by being stretched over the circumferential sidewall 16 and slid therealong towards the channels. The O-rings may return to their normal size when seated in the channels 20 and be retained therein by the walls of the channels. Alternatively they may remain under tension.

However, the O-rings 19 provided on the end faces 14, 15 are adhered to the channels 21 , 21 A by a suitable adhesive. In an alternative arrangement the annular channels 21 , 21 A formed in the end faces 14, 15 are provided with converging sidewalls, and the height of each sidewall is slightly greater than the radius of the O-rings, see Figure 4. This arrangement enables the O-rings 19 to be pressed into the channels 21 , 21 A and retained in place without requiring adhesive.

The upper fixture 11 comprises a plate adhered to the underside of the tabletop and the lower fixture 12 comprises a plate adhered to the uppermost surface of the table leg. The lower plate has a threaded stud 22 upstanding from the centre thereof and which engages the threaded bore 17 of the adaptor 10. The upper plate 11 has an annular flange 23 extending concentrically from its lowermost surface 24 and which defines a circular recess 25 for housing the cylindrical body 13. The cylindrical body 13 is adapted to be push-fitted into the circular recess 25 such that the O-ring 19 provided on the upper end face 14 engages the base 26 of the recess and the O-rings 18 provided on the circumferential sidewall 16 engage the wall 27 of the recess. In addition, an O-ring 29 is seated in channel 29A formed in the end of flange 23 and which bears against the surface of the lower plate 12, when the table is assembled.

A narrow opening 28 is formed in the annular flange 23 adjacent the lowermost surface 24 and through which air is expelled as the cylindrical body 13 is inserted into the circular recess 25.

Once the table is fully assembled and the or each leg is connected, any movement of the table top relative to the adaptor 11 and table leg causes the O-rings 18, 19 to compress (or expand) thereby absorbing the impact of the movement. It should be understood that it is not essential that the upper plate 11 is provided with the recess 25 and the lower plate 12 is provided with the threaded stud 22, the opposite would work adequately well. The degree of movement is small and may preferably not be perceptible to a person using the table, but it is enough to damp vibrations and attenuate stress.

Referring now to Figure 5, there is shown a second embodiment of the invention in which there is provided an adaptor, generally indicated 30, for connecting an upper plate 31 provided on a table top (not shown) to a lower plate 32 provided on a table leg (not shown). Like the first embodiment, the adaptor 30 of the second embodiment comprises a cylindrical body 33 having a circumferential sidewall 36 and upper and lower end faces 34,35. Four O-rings 38 are provided on the circumferential sidewall 36 and one O-ring 39 on each end face 34, 35, the O-rings are arranged to sit in channels similar to those featured in the first embodiment. Annular flanges 40, 41 extend concentrically from the upper and lower plates 31 ,32 and which define upper and lower recesses 42, 43, respectively. The recesses 42, 43 are generally of equal diameter and depth and are each adapted to receive an end of the cylindrical body 33 and form a push fit therewith. The upper flange has a free end remote from the upper plate on which there is provided an O-ring 44 arranged to bear against the free end 45 of the lower flange when the boss 10 and plates 11 , 12 are connected.

In each of the embodiments described above, the length of the cylindrical body 13, 33 and the depth of the or each recess are selected so the surfaces of the cylindrical body and the plates do not touch, but the O-rings engage a surface of a plate to which they are not fixed. In the event that the table is knocked, the O-rings are likely to absorb the impact of that knock by compressing in the direction of the force. For example, if that force has a

component parallel to the axis of the body 13, 33, the O-rings 19, 39 will compress thereby causing the plates to move toward one another.