GB2312707A

GB2312707A - Box leaf hinge

Info

Publication number: GB2312707A
Application number: GB9609331A
Authority: GB
Inventors: Richard Michael Dunne
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-05-03
Filing date: 1996-05-03
Publication date: 1997-11-05
Also published as: GB9609331D0

Abstract

A hinge comprises a plain leaf and a box section leaf. The hinge enables the legs of a saw horse, trestle, bench seat or the like legs to be folded together on axle pins B and also towards a supporting cross beam thus giving compact shape and easy portability. The plain leaf may be attached to the cross beam by screws, bolts, adhesive or welding.

Description

BOX LEAF HINGE This invention relates to a dual action hinge enabling foldable leg assemblies for saw horses, trestles, benches and the like.

The object of this invention is to enable the construction of foldable legs for saw horses, trestles, benches and the like by means of a dual action hinge which has great strength, stability and rigidity and which is very quick and simple to operate. This will make these items much more transportable and generally useful. Particularly with regard to trestles the increased portability and reduced stowage size afforded by the hinge will increase the number of occasions when trestles could be used.

According to the present invention there is provided a hinge constructed in steel brass, alloy or plastic which consists of two leaves. One of these leaves is attached to the underside of the main beam or cross member of the saw horse, trestle or bench by screws, bolts, adhesives or by welding. The other leaf is of box section (see figure 1) and houses the upper end of the folding legs which are fixed through the opposing faces of the box section by means of pins which act as axles for rotation of the legs enabling the legs to be folded together. The two leaves of the hinge can be opened out in the normal way enabling the legs to be folded immediately adjacent to and parallel to the main beam or cross member of the saw horse or trestle (see figure 3) The legs would be of square section at the top and where they meet in the open position these faces are cut or machined to give a larger area of contact between the two legs (figure 1 position A). This cutting or machining of the meeting faces combined with the positioning of the axle pins (figure 1 position B) would be such that where the legs emerge from the bottom of the box leaf section they would also be in contact with the sides of the box section (figure 1 position C) thus giving great rigidity to the structure in the open position. The angle of the legs when open is determined by these 3 points of contact, splaying the legs outwards and increasing the base width of the saw horse, trestle or bench.

The top of the box section leaf, when in the open position, rests against the underside of the beam or cross member. The angle of rest between the box leaf and the beam is determined by the angle at which the top edge of the box section is cut or machined. This angle is such that the legs are automatically splayed outwards to a predetermined position thus increasing the base length of the saw horse, trestle or bench.

The curve formed at the top section leaf (position D, figure 1.) is such that there is friction between the box section leaf and the underside of the cross beam during opening and closing of the hinge. This prevents the hinge from collapsing when being carried in the open position without additional support.

A specific embodiment of this invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows in end elevation the hinge supporting a channel section cross beam with the legs in the open position.

Figure 2 shows the hinge in side elevation Figure 3 shows the hinge with the legs in the folded or closed position Figure 4 shows an isometric view of a saw horse with the legs splayed and the hinges in the open position.

Referring to the drawing the saw horse comprises a cross beam of channel section within which is screwed a rectangular timber section which forms the working surface. The saw horse is supported at either end by a pair of legs which are splayed in both directions to give the maximum stability to the working surface. The upper ends of the legs are housed within the hinge enabling the whole device to be folded to a minimum size in two stages.

1. The legs are folded together so that they are parallel to one another.

2. The pair of legs at either end of the saw horse are then rotated until they are parallel to and immediately adjacent to the cross beam.

Claims

1. A hinge comprising a plain leaf in combination with a box section leaf.

2. A hinge as claimed in Claim 1 which will enable the legs of supporting devices such as saw horses, trestles, benches or similar to be folded under the supporting beam or cross piece thus giving great portability.

3. A hinge as claimed in Claim 1 with a box section leaf wherein means are provided for supporting legs or similar to be mounted on axle pins within the box enabling the legs to be rotated in a plane at 90 degrees opposed to the plane of operation of the main leaves.

4. A hinge as claimed in Claims 1, 2 & 3 where three points of contact are provided for the supporting legs thus giving great stability when in use,

5. A hinge as claimed in Claims 1, 2, 39 & 4 where the plain leaf may be fixed by screws, bolts, adhesives or welds to a cross beam or channel section of a saw horse, trestle, bench or similar.

6. A box leaf hinge substantially as described herein with reference to figures 1.4 of the accompanying drawing.