Fire escape – ladder – or scaffold – Unitary foldable – rigid scaffold or ladder – Trestle
Reexamination Certificate
2002-03-01
2004-03-30
Thompson, Hugh B. (Department: 3634)
Fire escape, ladder, or scaffold
Unitary foldable, rigid scaffold or ladder
Trestle
C182S225000
Reexamination Certificate
active
06712180
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sawhorse and, more particularly, to a height adjustable sawhorse. The present invention further relates to a sawhorse having independently moving leg members that allow height adjustment to be readily and easily accomplished.
2. Description of the Related Art
A sawhorse is a movable frame or trestle for supporting wood or another workpiece while it is being sawed or for supporting plates to provide working spaces. A sawhorse typically includes two leg members hingedly connected at the tops thereof and a spread limiting mechanism which defines the working spread at their bottom.
Traditionally sawhorses were made of wood or metal, however, following the technological progress of the plastic industry, sawhorses are nowadays also available from plastic materials.
For whatever purpose it is employed, it is advantageous for a sawhorse to be adjustable in height because it enables users of different heights to adjust the height of the sawhorse to be most comfortable for them. Sawhorses capable of height adjustment can be used in a wider variety of applications than sawhorses without this capability.
Prior art sawhorses are known which are height adjustable. Such devices have extendible/retractable extensions housed by the lower ends of their leg members. One such device is shown in U.S. Pat. No. 6,164,413. This device suffers a limitation because the process of adjusting the height is highly demanding. It requires a user to both adjust individual vertically-adjustable extensions in each sawhorse and secure each vertically-adjustable extension with a respective locking pin during height adjustment all the while holding the vertically-adjustable extension in the adjusted position.
It is an object of the invention to provide an improved adjustable sawhorse.
SUMMARY OF THE INVENTION
According to one aspect of the present invention there is provided a sawhorse comprising an elongated workpiece supporting structure and a pair of leg assemblies. The pair of leg assemblies supports the workpiece supporting structure. Said pair of leg assemblies is movable between a folded position for storage and transportation purposes and an operative position. Connecting structure connects with the leg assemblies below the workpiece supporting structure. The connecting structure is constructed and arranged to retain the leg assemblies in the operative position thereof and to allow movement of the leg assemblies between the operative and folded positions thereof. Each leg assembly includes a pair of separate lower leg members having lower portions. The lower portions are constructed and arranged to engage a horizontal support surface for the sawhorse when the pair of lower leg assemblies is retained in the operative position by the connecting structure thereof. This enables the workpiece supporting structure to be supported at a predetermined height above the horizontal support surface. Each of the lower leg assemblies is mounted for independent movement in a generally vertical direction and can be adjusted to a plurality of different positions with respect to the associated leg assembly and the connecting structure while the pair of the leg assemblies are retained in the operative position thereof by the connecting structure. A releasable locking member for each leg member is mounted in the connecting structure for movement between a releasing position and a locking position. In the releasing position, the releasable locking member is operable to release the associated leg member from movement into a selected one of the plurality of adjusted positions thereof. In the locking position, the releasable locking member is operable to lock the associated leg member within the adjusted position selected.
In another embodiment of the invention, the releasable locking member is spring biased into the locking position thereof for movement between the releasing and locking positions.
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Pillsbury & Winthrop LLP
Thompson Hugh B.
Zag Industries Ltd.
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