SECURING DEVICE This invention relates to securing devices for use in the construction of pieces of furniture.
Many items of furniture, and in particular furniture for fitted kitchens, are constructed from panels, normally of chipboard, which extend horizontally to form bottom shelves, intermediate shelves and tops, and vertically to form the upright ends of units or sections of the furniture items. Normally the horizontal panel which forms the bottom shelf has an edge face which butts against a major face of a vertical panel.
A wide variety of fittings, often referred to as "knock-down fittings", are known and sold which are used for securing the panels together at right angles to each other. Each such fitting requires one or more recesses to be drilled in the underside of the horizontal panel in the vicinity of its edge-face.
It is also known for units of fitted kitchen furniture to be supported above ground level by means of legs. The legs preferably are provided with a facility, such as a foot which is screw threaded to an upper part of the leg, such that the length of the leg can be adjusted so that the furniture can be made to stand accurately horizontally, and firmly on all its legs, despite the floor on which it stands being
uneven. Such legs have usually been fitted to the underside of the lowest horizontal panel of the piece of furniture, in the vicinity of its edges which butt against vertical panels. To enable the horizontal panel to have the leg secured to it, its underside has to be drilled with recesses for the one or more screws or plug fittings that are used to secure the leg fitting to the underside of the panel.
Consequently, the panels of chipboard or other material from which the lowest horizontal panels in such furniture are to be made, or have been made, have needed to be drilled with two separate sets of recesses, one set for the knock-down fittings and another set for the leg fittings, and this has been the practice for many years.
Also, the loading which is applied to items of furniture is carried downwards through the vertical panels. This loading can be very substantial, for example the weight of a fairly heavy person. In constructions as just described above, this loading is transferred to the lowest horizontal panel through the knock-down fitting and then from a different part of the horizontal panel to the ground through the leg fitting. This has resulted in excessive loading breaking the furniture by forcing the knock-down fitting out from the underside of the horizontal
panel, i.e. the horizontal panel stays in its usual position, supported by the leg, and the vertical load- bearing panel moves downwardly relative to it breaking the knock-down fitting out of the horizontal panel as it goes.
An object of the present invention is to simplify the construction of pieces of furniture using horizontal and vertical panels, and which are to be provided with legs, and to reduce the risk of structural failure.
The invention provides a device for use in securing, to a piece of furniture which comprises a horizontal panel having an edge face which butts against a major face of a vertical panel, a member for supporting the weight of the piece of furniture, the device comprising a base having on its underside a mounting for, or at least a part of, said member, the upper side of the base being adapted to engage in and support said horizontal panel, and said base being provided with one part of a two part securing means, the other part of said securing means being adapted for engagement in said major face of said vertical panel, said securing means being operable to draw said base towards said vertical panel whereby in use to both secure said base to the vertical panel and to rigidly secure said horizontal panel in position
relative to said vertical panel.
The weight-supporting member may be a leg of the adjustable type as already referred to, or even of a non-adjustable type, which is mounted to the mounting on the device. Alternatively, one part of an adjustable leg may be made integrally with the device, the other part being threaded to the first part to provide adjustability. There may be a requirement for a very short weight-supporting member, for example simply for enabling the pieces of furniture to be slid over a floor with its panels clear of the floor, in which case the member may be made integral with the device. The weight-supporting member could also be provided in the form of a wheel or castor. A device in accordance with the invention transmits at least a substantial part of the loading forces from the weight-supporting member, through the securing means, into the vertical panel through its vertical face. Consequently, although the horizontal panel is still located above the fitting which rigidly secures the two panels together, it does not have forces transmitted to it tending to separate it from the fitting and the type of failure referred to above is therefore far less likely to occur. Also, since a device in accordance with the invention provides the necessary structural strength
for the joint between the horizontal and vertical panels as well as securing the weight-supporting member or leg to the furniture item, it is only necessary for the underside of the horizontal panel to be drilled with a single set of recesses, i.e. those needed to receive the necessary number of devices in accordance with the invention, and this is a substantial manufacturing economy compared with providing two sets of recesses as explained above. There is a further economy, in that only one set of devices have to be assembled with the panels, i.e. a set of devices in accordance with the invention, rather than a set of knock-down fittings and also a set of leg fittings. The adaptation by means of which a device in accordance with the invention engages with the underside of the horizontal panel may be made sufficiently similar, in relevant respects, to that of a normal or conventional knock-down fitting that an identical drilling pattern, normally of one or two recesses, can be used adjacent to the edges of all panels that are to be used as horizontal panels in the construction of furniture. They can then be equipped optionally with either normal knock-down fittings or with devices in accordance with the invention, depending on whether they are to used as lowermost
panels equipped with legs, or not. This, of course, offers yet a further economy. It will be appreciated that, although three kinds of securing means usable in a device of the invention are specifically described below, there are other kinds adapted for securing panels at right angles that could be used.
In order that the invention may be more clearly understood, some embodiments will now be described, by way of example, with reference to the accompanying diagrammatic drawings in which:
Figure 1 shows partly in cross-section a first embodiment of the invention, in use,
Figure 2 shows a side elevation of a second embodiment of the invention in most respects the same as the first,
Figure 3 shows a plan view from below of the second embodiment,
Figure 4 shows a cross-section of the second embodiment taken on the line A-A in Figure 3, Figure 5 shows an elevation of the second embodiment looking in direction B of Figure 2,
Figure 6 shows an elevation of the second embodiment looking in direction C of the Figure 2, and
Figure 7 shows a third embodiment of the invention in use.
Features of the embodiments which are the same or
similar will be indicated by the same reference numerals throughout, wherever appropriate.
Referring first to Figure 1, a device 2 in accordance with the invention is used to rigidly secure a horizontal panel 6 at right angles to a vertical panel 8 and also to secure a furniture leg genei-lly indicated at 10 to the piece of furniture of which the panels form part.
The device 2 comprises a substantially flat base 12 which extends right up to the edge of the horizontal panel 6 and which on its other side is adapted to engage in and support that panel. The engagement is provided by means of a relatively large diameter plug portion 14 and a smaller plug portion 16 located to the side of plug portion 14 remote from the edge of horizontal panel 6. The panel 6 is provided with respective recesses 18 and 20, by means of a drilling operation, which are of sizes such that the two plug portions are a tight force fit into the recesses.
As will become clearer after Figures 2 to 6 have been described, the plug portion 14 forms one part of a two part securing means of which the other part is a screw 22 having a threaded shank 24 adapted for engagement in a bore 26 in the vertical face 28 of vertical panel 8.
On its underside, the base 2 is provided with a hollow cylindrical spigot 30 having an external thread 32, this forming a mounting for the leg 10.
The base 2, plug portions 14 and 16, and spigot 30 are all moulded as a single component from suitable plastics material or cast from a suitable alloy.
The leg 10 is of an adjustable type consisting of an upper tubular part 34 which is internally threaded at its upper end so that it can be screwed over the spigot 30, and which is also internally threaded at its lower end so that a lower externally threaded leg part 36 can be screwed into it. A foot 38 is provided at the bottom of the lower leg part for engaging the ground or floor. The spigot 30 and leg 10 could be provided with a push-fitting arrangement instead of interengaging threads.
In manufacture and assembly, the underside of the horizontal panel 6 is drilled with as many pairs of recesses 18 and 20 as may be necessary, normally one pair near the front of the panel and one pair near the back. The vertical panel 8 is drilled with a corresponding bore 26 for each pair. The device 2, with the screw 22 located within it then has its plug portions 14 and 16 force-fitted into the recesses 18 and 20 and, with the horizontal and vertical panels 6 and 8 correctly aligned with each other, a screwdriver
40 is inserted through a specially-provided aperture indicated by broken lines 42 to engage with the head of the screw, this head being of an angle drive type so that it can be turned reliably by a screwdriver at an angle to the screw axis. The screw is then tightened into the bore 26 and this draws and clamps the two panels 6 and 8 rigidly together and at the same time secures the spigot 30 directly to the vertical panel 8 through its vertical inner face 28. It can be seen that if the vertical panel 8 is heavily loaded downwards by a load imposed on the piece of furniture of which it forms part, that load will be transmitted by the screw 24 to the plastics device 2 and from there into the leg 10 and hence to the ground or floor. The load does not have to be transmitted across the interface between the device 2 and the horizontal panel 6 and hence does not tend to break the components apart at this interface as has happened using prior assembly systems. At its upper end, the upper leg part 34 has an outwardly extending flange portion 44 which projects laterally beyond the base 2 and lies under and in contact with part of the edge face of vertical panel 8. This enables a part of the vertical loading to be transmitted directly from the lower edge of panel 8 to the leg 10 via flange 44, so that the screw 22 and
bore 26 do not have to carry the whole of that loading.
Turning now to the embodiment shown in Figures 2 to 6, it is not necessary to repeat the description of those features already explained with reference to Figure 1. It can be seen that the plug portion 14 is formed with angled ribs 46. These do not substantially hinder forcing the plug portion into the bore 18, but do resist it coming out. The base 2, as best seen in Figure 3, is approximately square and in that Figure it can also be seen that the spigot 30 is located in the close vicinity of the left-hand edge of the base 2 so that it is as near as possible, when in use, to the vertical panel 8 whereby to minimise so far as possible the bending forces applied to the components when a load is being transmitted from the vertical panel 8 to the leg 10.
In Figure 3 it can also be seen that the second embodiment is provided with two countersunk holes 48 which can accommodate self-tapping screws which are used in place of the second plug portion 16 of the first embodiment to additionally secure the base 2 to the underside of horizontal panel 6. The use of screws has the advantage that they only require small and shallow starting-points to be drilled in the underside of panel 6. A drilling set-up used for this
purpose will drill the large recess 18 for the plug portion 14, plus the two starting-points. Since ordinary knock-down fittings are well-known which fit into a recess of the same positioning, shape and size as the recess 18, that drilling set-up may be the only one that is used on horizontal panels, since the resulting recess 18 could accommodate the plug portion of either a conventional knock-down fitting or a unit in accordance with the invention, and the existence of the two small starting-points at positions where units in accordance with the invention are not actually to be fitted will not matter since they will be un- noticeable.
Referring to Figures 2, 4 and 6, the screw 22 is inserted into the device through an opening 48 in the rear of the plug portion 14. Small internal ribs 50 are provided (see Figure 4) to lightly hold screw 22 (shown in broken lines in Figure 4) in position within the device before the screw is tightened. Referring to Figures 4 and 6, an aperture 52 in the rear of spigot 30, in conjunction with the hollow interior of the device, provides the access previously referred to as opening 42 which enables a screw driver to reach into the device for tightening screw 22. Reference is made to US Patent Application Nos.
447,474 and 538318 for further detailed description of
a securing device of the type used in this embodiment in the form of plug portion 14 and its associated screw 22.
Referring to Figure 7, the third embodiment of the invention there shown is the same as that in Figure 1 except for the nature of the securing device. In Figure 7, one part of the securing means comprises a projection 54 moulded integrally with the plug portion 14 and extending laterally therefrom at right angles to the edge face of horizontal panel 4. The other part of the securing means comprises a plug-like housing 56 press-fitted into a bore 58 in vertical panel 8 and containing a cam member 60 which can be rotated by a screwdriver 40 so as to engage with a shoulder portion 62 on the projection 54 and draw the projection 54 inwardly of the housing 56 so as to tighten the joint between the panels and tightly secure the spigot 30 to the vertical panel 8. For further details of a securing means of this type, reference is made to British Patent No. 1447387.
A further type of securing means, known per se, which could be utilised in devices according to the invention comprises a rotatable camming member which, in the present application, would be located within plug portion 14 and would be rotatable about an axis perpendicular to horizontal panel 6. Instead of screw
22, a dowel pin is screwed or driven into the vertical panel 8 and its head extends into the rotatable camming member. The latter is designed such that when it is rotated with a screwdriver it engages with both sides of the screw head and draws the screw inwardly of the camming member so as to tighten the joint, and, in a device in accordance with the invention, to secure the spigot 30 to the vertical panel 8. A recent example of a device of this type is described in British Patent Application No. 9017313.
It should be appreciated that although leg 10 will for most purposes be required to be of an adjustable type, a leg of fixed length might be screwed onto spigot 30. Further, a complete leg might be moulded integral with the rest of the device in place of spigot 30. Instead of a leg, a weight- supporting member generally similar in shape and size to spigot 30 but without the external thread and with a slightly convex bottom might be moulded integrally with the device to permit the piece of furniture to be slid over a floor. The device might also incorporate, in place of spigot 30, a mounting suited to receive a castor, for use on furniture which is to be wheeled about. Such a mounting may be arranged so that the shaft of the castor is housed within the smaller plug portion 16 and retained there, for example by push-fit engagement.