AU710975B3

AU710975B3 - A trestle

Info

Publication number: AU710975B3
Application number: AU41136/99A
Authority: AU
Inventors: Jonathan Charles Gillham
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-07-26
Filing date: 1999-07-26
Publication date: 1999-09-30
Anticipated expiration: 2000-09-30

Description

1

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A PETTY PATENT Name of Applicant: Actual Inventor: Address for Service: Invention Title: Jonathan Charles GILLHAM As above CULLEN

CO.,

Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, QId. 4000, Australia.

A TRESTLE The following statement is a full description of this invention including the best method of performing it known to me: A TRESTLE This invention relates to a trestle and particularly relates to a general purpose adjustable builder's trestle.

A trestle can be defined as a braced frame assembly which serves as a load bearing support. Typically a trestle contains two spaced apart leg members interconnected by a beam.

In use, two such trestles are spaced apart, and planks, boards, and the like can be supported on the spaced apart trestles for sawing, drilling or for other work.

One widely available trestle is a sawhorse which is usually formed from wood. The sawhorse is a solid integral unit and consists of two spaced apart leg assemblies, each leg assembly being of an inverted V-type configuration and having splayed apart legs. A wooden beam is bolted, glued or nailed to each leg assembly to form the sawhorse. While this type of sawhorse is strong and robust, it is very bulky and it is not possible to easily dismantle or stack the sawhorses for transportation or storage. These existing sawhorses are also not length or height adjustable which somewhat limits their suitability.

To date, there has not been available a trestle which can be height adjustable as well as length adjustable to provide maximum versatility and which can be adjusted and dismantled fairly simply to facilitate transportation and storage.

It is an object of the invention to provide a trestle which may overcome the abovementioned disadvantages or provide the public with a useful or commercial choice.

In one form, the invention resides in a trestle having a pair of leg assemblies and a beam connected to each leg assembly, each leg assembly having at least one ground engagable foot, a beam attachment member which has a collar through which the beam can pass to attach the beam to the leg assembly, and height adjustment means to adjust the height of the beam attachment member relative to the ground and therefore the height of the beam above the ground.

In another form, the invention resides in a trestle as described above wherein the leg assemblies are angled outwardly relative to tfie beam, while the collar, which is part of the beam attachment member, remains substantially horizontal.

The trestle has many advantages including the ability to be dismantled into components which can be more easily stacked or stored, the ability for the beam to be height adjustable to accommodate the work piece and/or the height of the person using the trestle, and the ability of the trestle to be length adjustable in a fairly simple yet safe manner.

The trestle has a pair of leg assemblies. Each leg assembly has at least one ground engageable foot. In one form, the leg assembly has a substantially inverted U-shape or V-shape to define two spaced apart ground engageable feet. It is preferred that the leg assembly has a pair of spaced apart feet to provide improved stability, although it is envisaged that a single long foot could also be provided to provide the same effect.

The leg assembly may consist of a framework of tubular or solid members attached together by welding or fasteners to provide a strong rigid unit.

Each leg assembly has a beam attachment member which has a collar through which the beam can pass to attach the beam to the leg assembly.

The collar may be tubular and preferably has a cross-section which is substantially identical to the cross-section of the beam but being slightly larger than the beam. For instance, if the beam has a rectangular cross-section, the collar may also have a rectangular cross-section of slightly larger size to allow the beam to slide through the collar.

The collar should be such that while the beam can slide through the collar, the beam cannot be lifted out of the collar except by the sliding motion. Thus, while the collar can be tubular, it may also have weight reducing voids or cut-outs which are sized and shaped to prevent the beam from being lifted out of the collar. The collar may have a C-shaped or Ushaped cross-section with the free ends having at least one turned in lip or rib sufficient to prevent the beam from being lifted out of the open part of the C or U-shaped collar. The collar may alternatively comprise a pair of opposed Cshaped sections, which together define a rectangular cross-section. The Cshaped sections can be spaced apart but not by a distance to allow the beam to be simply lifted out of or into the C-shaped sections. The length of the collar can vary to suit. If the collar is made of extremely strong steel, the length of the collar may be quite small. On the other hand, the collar can be made from lighter gauge steel in which case the length of the collar may need to be longer in order to properly support the beam.

By allowing the beam to slide along and through the collar on each leg assembly, the spacing between the leg assemblies can be easily adjusted thereby allowing the trestle to have an easy length adjustment capability.

If desired, some type of locking means can be provided to lock the leg assemblies to the beam. This can be in the form of a locking nut.or bolt, pin and slot, or other type of convenient arrangement.

In one form, the leg assemblies can be releasably locked to the beam when a load is applied to the beam, or by the weight of the beam itself.

This can be achieved by having the leg assemblies splayed outwardly relative to the beam while having the collar remaining substantially horizontal. This provides a locking action because as a load is applied to the beam, or by the weight of the beam itself, the load is transferred to the outwardly splayed legs which in turn causes the collar to angle slightly downwardly such that the internal walls of the collar clamp against the beam. When the load is removed from the beam, or by slightly lifting the beam, this clamping action is released and the leg assemblies can be simply slid along the beam or entirely off the beam.

The trestle has a height adjustment means ultimately to adjust the height of the beam above the ground. The height adjustment means may be part of the leg assembly. In one form, the height adjustment means comprises a vertically extending elongate member attached to the collar with the elongate member being selectively lockable to the remainder of the leg assembly at various positions to vary the height of the collar relative to the remainder of the leg assembly.

In another form the invention resides in a leg assembly as described above.

An embodiment of the invention will be described with reference to the following drawings in which Figure 1 illustrates a trestle according to an embodiment of the invention having two leg assemblies and a cross beam.

Figure 2 is a plan view of a leg assembly.

Figure 3 is a side elevation view of the leg assembly of Figure 2.

Figure 4 is a front elevation view of the leg assembly of Figure 3.

Referring to the drawings, there is illustrated a trestle 10 which consists of a pair of leg assemblies 11, 12 and a cross beam 13. Each leg assembly has at least one ground engageable foot and in the embodiment has a pair of spaced ground engageable feet 14 and a beam attachment member which includes a collar 16 through which beam 13 can pass. The trestle further contains a height adjustment means 17 which will be described in greater detail below.

Each leg assembly can be formed from tubular or boxed steel which can be bent, welded or otherwise attached to form a strong rigid unit.

In the embodiment, each leg assembly is of an inverted U or V-shaped configuration to define a pair of spaced apart feet 14 and a supporting cross strut 18.

The beam attachment member comprises a collar 16 which in the embodiment is formed from a metal box section which is entirely hollow.

Collar 16 has a length of approximately 200mm and an internal cross-section size which is roughly the same shape and slightly larger than the crosssection of beam 13 which allows beam 13 to be simply slid through the collar 16 of each leg assembly 11, 12 and as illustrated in Figure 1.

Better illustrated in Figure 3, each leg assembly is angled outwardly or splayed while collar 16 remains substantially horizontal. When a load is applied to beam 13, or by the weight of beam 13 itself, the load is transferred to the splayed legs which causes a slight angling of collar 16 to releasably clamp collar 16 to beam 13. Thus, as long as a load is applied to the beam or by the weight of the beam itself, the leg assemblies are unlikely to inadvertently slide along the beam.

However, when the load is removed or by simply slight lifting of beam 13, each leg assembly can be slid off the beam or adjusted along the beam to provide length adjustment.

The leg assembly has a height adjustment means 17. In the embodiment, the height adjustment means is a telescoping assembly which consists of an outer hollow box section 20 which is rigidly attached to the remainder of the leg assembly. An inner smaller sized box section 21 is able to slide through outer box section 20 and is provided with a number of openings 22 which enable inner box section 21 to be locked to outer box section 20 via a locking pin 23.

The top of inner box section 21 is welded or otherwise attached to collar 16 such that height of collar 16 and therefore the height of beam 13 is height adjustable.

It should be appreciated that various other changes and modifications may be made to the embodiment described without departing from the spirit and scope of the invention as claimed.

Claims

1. A trestle having a pair of leg assemblies and a beam connected to each leg assembly, each leg assembly having at least one ground engageable foot, a beam attachment member which has a collar through which the beam can pass to attach the beam to the leg assembly, and height adjustment means to adjust the height of the beam attachment member relative to the ground and therefore the height of the beam above the ground, the leg assemblies being angled outwardly relative to the beam, while the collar, which is part of the beam attachment member, remains substantially horizontal.

2. The trestle of claim 1 substantially as hereinbefore described with reference to the drawings. DATED this 18 th day of August 1999 Jonathan Charles GILLHAM By his Patent Attorneys CULLEN CO.