GB2153214A - Stool - Google Patents

Abstract

A stool comprises a pair of spaced tubular frames 1. One side 7 is formed by tucking the swaged end 3 of the tube into the other open end 2. The adjacent sides 5 and 6 are interconnected by a strut 4 located close to but spaced from and parallel to the jointed side 7. The struts 4 are interconnected by load-bearing frame-spacing tubes 8, as are the sides 6. The struts reinforce the jointed sides so that the joints need not be welded. Preferably, the connections between struts 4 and sides 5, or between members 8 and struts 4 or sides 5, are by means of a female plug 10 fitted into the end of one tube and a male plug with external taper 19 fitting into plug 10 and having its body shaped at 20 to fit around the side of a second tube. Screw 17 is passed through aperture 22 into these plugs. Plug 10 has radial slots 18 allowing expansion on insertion of the male plug. <IMAGE>

Description

SPECIFICATION Stool The present invention relates to a stool.

As used herein, the term stool is used in a broad sense and has a broad meaning. Accordingly the term is not restricted to mean a piece of furniture which is lower than a conventional chair and is intended merely for sitting and kneeling on.

Our registered design No. 1,010,358 is in respect of a specific stool of the general type contemplated in our invention. It is contemplated that the stool may be knelt on, sat on, stood on, or indeed used as a carrying platform.

The object of our present invention is to provide a particularly advantageous manner of construction of the type of stool.

A stool of the invention comprises a pair of generally rectangular tubular frames, each frame having a joint in one side of its frame; a pair of struts, each frame having its own strut interconnecting the two respective sides of the frame adjoining the said one, jointed, side of the frame, and at least one frame spacing means interconnecting the two frames for load-bearing.

Provision of the strut in each frame between the sides adjoining the jointed side reinforces the joint. This enables the joint to be comparatively weak. For instance the joint need not be welded and, preferably, is formed by tucking a swaged end of the tube from which the frame is formed inside the other, open, end of the tube. Such a joint has virtually no strength in tension and is not particularly strong in compression. The strut provides strength in compression, which is the likely loading mode, and in tension according to the tensile strength of the joints between the strut and the said adjoining sides.

Preferably the strut is parallel to the jointed side and spaced less than 50% of the length of the adjoining sides from the jointed side.

The joints are preferably effected by means of the connectors described in patent application No. 8310793. Broadly this connector comprises a female plug having a tapered bore and an external dimension to fit inside the open end of a first tube; a male plug having a complementary external taper at one end for fitting in the female plug and a body at the other end shaped to receive the contour of a second tube (or other component to be connected); and a screw for drawing the second tube (or other component) onto the body and drawing the male plug into the female plug thereby expanding the female plug to jam in the open mouth of the first tube.

In the preferred form of connector used in the preferred stool of the invention, the female plug has an external groove for accommodating the internal welding flash of the first tube, slits to assist expansion and a rim to locate it at the end of the tube whereby the tube is held at its very end; and the male plug has an abutment surface for abutting the rim.

Although it is envisaged that the struts may be used solely for reinforcing the frame joints, they preferably support the or one of the loadbearing frame-spacing means. With the struts spaced, as they preferably are, close to the jointed side of the frame, the load-bearing means thereby provide alternative load-bearing heights according to whether the jointed sides of the frames or the opposite sides are supported on the ground for instance.

Preferably other load-bearing means are provided between respective ones of the said adjoining sides, whereby a third load-bearing height is provided.

It is envisaged that each load-bearing means may be a pressed sheet metal member.

To facilitate it having a comfortable surface on both sides, each load-bearing means may alternatively be a hollow plastics material extrusion of similar overall thickness to that of the frame sides. End caps conforming to the shape of the frame sides and screwed rods passing through the extrusion and the frame sides may be provided. In another alternative, the load-bearing means may be a pair of tubular members interconnected by a short tubular member. However each load-bearing means is preferably a pair of tubular members which are un-interconnected themselves save by the frames. Conveniently two pairs are provided. Preferably a platform of moulded plastics material is provided for clipping onto either pair of tubular members on either side thereof.

The frames are preferably substantially square with the load-bearing means separating them whereby they define a cube. The sides of the frames may be slightly bent to provide for ground contact at the corners only. However in view of slight flexibility of the stool, which enables it to accommodate slight ground unevenness, such bending is usually unnecessary. In order to enhance stability by spreading the load base, the corners of the frames are preferably bent to small radius with "crush bends".

To help understanding of the invention a specific embodiment thereof will now be described by way of example and with reference to the accompanying drawings in which: Figure 1 is a perspective view of a stool according to the invention; Figure 2 is a perspective view of a platform for use with the stool; Figure 3 is a plan view of the stool knocked down for package; Figure 4 is a side view of the knocked down stool; and Figure 5 is a cross-sectional scrap view on the line V-V in Fig. 3 showing a connector on a larger scale.

The stool shown in Fig. 1 includes two 18" (450 mm) square frames 1 of 1" (25 mm) OD aluminium tube, crush bent at the corners. One end 2 of the tube of each frame is plain, whilst the other end 3 is swaged down in diameter and tucked into the open end 2.

In each frame, a strut 4 of the same tubular material is interconnected between sides 5,6 of the frame adjoining the jointed side 7 at 20% of the length of the adjoining sides 5,6 from the jointed side 7 of the frame. The struts 4 and the sides 5 are interconnected, from one frame to the other by load-bearing (in use) tubular members 8 of the same tubular material. The moulded plastics platform 9 shown in Fig. 2 can be clipped over the tubular members 9 and the portions of the struts 4 between the members 9 form a load platform which may be knelt, sat or stood on.

If the stool is inverted from its Fig. 1 position the platform 9 may be clipped on the opposite side of the members 8 and struts 4 to form a different height platform. Again if the stool is rotated 90 in either direction from the Fig. 1 position the platform can be clipped to the other struts 8 to provide a load platform at either of the resulting heights of the other struts 8.

Referring next to Fig. 5, the design of connector there shown is used for connecting both the struts 4 to the frames 1 and the members 8 to both the struts 4 and the sides 5. A female plug 10 of each connector, having a groove 11 to accommodate welding flash 12, has an external diameter 1 3 such that it closely fits in the mouth of its tube. It is limited from being slid totally into the tube by a rim 14. The bore 1 5 of the female plug is outwardly tapered and is closed at its inner end by a boss 16 having a central aperture for a screw 1 7. In the region of its tapered bore 1 5 the female plug has radial slots 1 8 allowing expansion of the plug on insertion of the male plug.The latter has a complementary external taper 1 9 at one end and a body shaped at 20 to fit the side of the second tube. Between the taper 1 9 and the body 20 is an abutment surface 21 for abutting the end of the female plug at the rim 14. The male plug has a central aperture 22 for the screw 1 7 which also passes through the second tube at piercing 23.

On tightening of the screw, the second tube is drawn onto the body 20 and the male plug is drawn into the female plug. The latter expands due to the tapers and grips its tube at its mouth. The resulting connection of the tubes is firm and not susceptible to fretting at the mouth of the first tube due to tight fitting of the connector at the mouth.

Turning now to Fig. 3, in the knocked down form of the stool- the struts 4 are fitted between the sides 5,6 with Fig. 5 connectors, whereby the frame is rigid. Connectors, including their male plugs are fitted in the ends of the members 8. Due to the reduction in thickness dimension of the tube of the frames 1 at the corners on crush bending, the members 8 can be dropped in to fit between the sides 5,6 as shown in Fig. 5.

The invention is not intended to be restricted to the details of the above exemplary embodiment. In particular steel tubes and other connectors could be used. However the use of aluminium tube and the described connectors gives a lightweight. yet adequately strong stool. Typically the stool weighs 2 kilograms yet will support 100 kilograms.

Claims (11)

1. A stool comprising a pair of generally rectangular tubular frames, each frame having a joint in one of its four sides, a strut for each frame to interconnect the two sides adjacent to the one jointed side, and at least one loadbearing, frame-spacing means to interconnect the two frames.

2. A stool according to claim 1, in which the joint is formed by tucking a swaged end of the tube from which the frame is formed inside the other end of the tube, which end is open.

3. A stool according to claim 1 or 2, in which each strut is parallel to the jointed side of its frame and is spaced less than 50% of the length of the adjacent sides from the jointed side.

4. A stool according to claim 3, in which the spacing of the strut from the jointed side is 20% of the length of the adjacent sides.

5. A stool according to any preceding claim, in which load-bearing means is connected between the struts of the two frames.

6. A stool according to claim 5, in which the load-bearing means is in the form of two spaced tubes.

7. A stool according to any preceding claim, in which the load-bearing means is connected between corresponding adjacent sides of the frame.

8. A stool according to claim 7, in which the load-bearing means is in the form of a pair of spaced tubes.

9. A stool according to claim 6 or 8, in which the two spaced tubes are interconnected by a short tubular member between their ends.

10. A stool according to claims 6,8 or 9, including a platform with means to clip the platform to a pair of spaced tubes.

11. A stool according to any preceding claim, in which the frames are substantially square.

1 2. A stool according to any preceding claim, in which the connections between the struts and sides or between the load-bearing means and the struts or sides are in the form of female plugs having tapered recesses fitted into the ends of tubes, and externally tapered male plugs shaped to fit around part of the length of a tube and into a female plug, and a screw to pass through a tube and the male plug into the female plug to enable the plugs to be drawn together to secure them in the ends of the tubes.

1 3. A stool according to claim 12, in which the female plug has slits to assist expansion thereof, and a rim to locate on the end of a tube.

1 4. A stool according to claim 1 3, in which the male plug has an abutment surface to abut the rim of the female plug.

1 5. A stool substantially as hereinbefore described and illustrated in the accompanying drawings.