초록

A self-stabilizing trestle includes independently pivoting leg assemblies, which allow a substantially horizontal support surface defined by the trestle to be maintained stable when the trestle is placed on uneven terrain.

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1. A self-stabilizing trestle that provides a stable, substantially horizontal support surface when placed on uneven terrain, comprising:a crossbeam having a first end and a second end, and defining the substantially horizontal support surface; a first leg assembly disposed near the first end of sai

1. A self-stabilizing trestle that provides a stable, substantially horizontal support surface when placed on uneven terrain, comprising:a crossbeam having a first end and a second end, and defining the substantially horizontal support surface; a first leg assembly disposed near the first end of said crossbeam and secured to said crossbeam for pivoting about a first hinge defining a first rotation axis that is oriented at a predetermined acute angle relative to the support surface defined by said crossbeam; and a second leg assembly disposed near the second end of said crossbeam and secured to said crossbeam for pivoting about a second hinge defining a second rotation axis that is oriented at a predetermined acute angle relative to the support surface defined by said crossbeam; wherein said first and second leg assemblies each have a generally tetrahedral structure including three lateral faces joined along three lateral edges, said first hinge being secured to said first leg assembly along one of its lateral edges, and said second hinge being secured to said second leg assembly alone one of its lateral edges: wherein said first and second hinges allow for independent pivoting of the first and second leg assemblies about said first and second rotation axes and relative to said crossbeam, thereby allowing the support surface defined by said crossbeam to be maintained at a substantially horizontal orientation when said first and second leg assemblies are placed on uneven terrain. 2. The self-stabilizing trestle as recited in claim 1, wherein the predetermined acute angle associated with the orientation of said first rotation axis is substantially equal to the predetermined acute angle associated with the orientation of said second rotation axis.3. The self-stabilizing trestle as recited in claim 1, wherein said first and second leg assemblies each include a pair of feet that firmly contact the terrain upon which said trestle is positioned.4. The self-stabilizing trestle as recited in claim 3, wherein said first leg and second assemblies each include a spreader brace for resisting both compression and tension, such that, when the self-stabilizing trestle is placed for use, the distance between the respective feet of each leg assembly remains substantially constant.5. The self-stabilizing trestle as recited in claim 3, wherein each foot is equipped with an independently rotating wheel.6. The self-stabilizing trestle as recited in claim 5, wherein the predetermined acute angles associated with the orientation of each rotation axis are less than approximately 80 degrees.7. The self-stabilizing trestle as recited in claim 1, wherein said crossbeam comprises an upper flange that defines said horizontal support surface and a lower web portion that operably connects said upper flange to said first and second leg assemblies.8. The self-stabilizing trestle as recited in claim 7, wherein the lower web portion of said crossbeam is a substantially trapezoidal plate having parallel upper and lower base edges and first and second side edges, the upper planar member of said crossbeam being secured to the upper base edge of said plate, and the fist and second leg assemblies of said trestle being pivotally connected to the plate along said first and second side edges by said first and second hinges.9. The self-stabilizing trestle as recited in claim 1, wherein the predetermined acute angles associated with the orientation of each rotation axis are less than approximately 44 degrees.10. A self stabilizing trestle that provides a stable, substantially horizontal support surface when placed on uneven terrain, comprising:a crossbeam having a first end and a second end, and defining the substantially horizontal support surface; a first leg assembly disposed near the first end of said crossbeam and secured to said crossbeam for pivoting about a first hinge arrangement that is oriented at a predetermined acute angle relative to the support surface defined by said crossbeam; and a second leg assembly disposed near the second end of said crossbeam and secured to said crossbeam for pivoting about a second hinge arrangement that is oriented at a predetermined acute angle relative to the support surface defined by said crossbeam; wherein said first hinge arrangement comprises a pair of hinges positioned on either side of said crossbeam for rotation about a first set of substantially parallel rotation axes, and said second hinge arrangement comprises another pair of hinges positioned on either side of said crossbeam for rotation about a second set of substantially parallel rotation axes; and wherein said first and second hinge arrangements allow for independent pivoting of the first and second leg assemblies about said first and second sets of rotation axes and relative to said crossbeam, thereby allowing the support surface defined by said crossbeam to be maintained at a substantially horizontal orientation when said first and second leg assemblies are placed on uneven terrain. 11. A self-stabilizing trestle that provides a stable, substantially horizontal support surface when placed on uneven terrain, comprising:a crossbeam having a first end and a second end and defining the substantially horizontal support surface; a first leg assembly disposed near the first end of said crossbeam and secured to said crossbeam by a first set of coaxial hinges, said first set of coaxial hinges defining a first rotation axis that is oriented at a predetermined acute angle relative to the support surface defined by said crossbeam; and a second leg assembly disposed near the second end of said crossbeam and secured to said crossbeam by a second set of coaxial hinges, said second set of coaxial hinges defining a second rotation axis that is oriented at a predetermined acute angle relative to the support surface defined by said crossbeam; and wherein said first and second sets of coaxial hinges allow for independent pivoting of the first and second leg assemblies relative to said crossbeam, thereby allowing the support surface defined by said crossbeam to be maintained at a substantially horizontal orientation when said leg assemblies are placed on uneven terrain. 12. The self-stabilizing trestle as recited in claim 11, wherein the predetermined acute angle associated with the orientation of said first rotation axis is substantially equal to the predetermined acute angle associated with the orientation of said second rotation axis.13. A self-stabilizing trestle for maintaining a stable work surface at a substantially horizontal orientation over an uneven terrain, comprising:a crossbeam extending substantially the length of said trestle and supporting the work surface, said crossbeam having a pair of ends; and first and second leg assemblies each positioned adjacent a respective crossbeam end, each of said leg assemblies being pivotally connected to said crossbeam so as to independently pivot along respective first and second pivot axes, said first and second pivot axes downwardly converging toward one another and being essentially coplanar in a substantially vertically disposed plane bisecting said trestle, each of said leg assemblies downwardly extending from said respective first and second pivot axes and terminating in at legst two support feet spaced from one another across said bisecting plane. 14. A self-stabilizing trestle that provides a stable, substantially horizontal support surface when placed on uneven terrain, comprising:a crossbeam having a first end and a second end and defining the substantially horizontal support surface, a first hinge being secured to said first end of the crossbeam and defining a first rotation axis, a second hinge being secured to said second end of the crossbeam and defining a second rotation axis, wherein said first and second rotation axes intersect below said support surface, and wherein said horizontal support surface, said first rotation axis, and said second rotation axis form a triangle; a first leg assembly secured to said crossbeam by said first hinge between first and second endpoints of said first hinge for pivoting about said first rotation axis, said first leg assembly having first and second feet for contacting the terrain upon which said trestle is placed, wherein the first endpoint of said first hinge, the second endpoint of said first hinge and said first foot form a triangle, and wherein the first endpoint of said first hinge, the second endpoint of said first hinge and said second foot form a triangle; and a second leg assembly secured to said crossbeam by said second hinge between first and second endpoints of said second hinge for pivoting about said second rotation axis, and said second leg assembly having third and fourth feet for contacting the terrain upon which said trestle is placed, wherein the first endpoint of said second hinge, the second endpoint of said second hinge and said third foot form a triangle, and wherein the first endpoint of said second hinge, the second endpoint of said second hinge and said fourth foot form a triangle; wherein said first and second hinges allow for independent pivoting of said first and second leg assemblies and relative to said crossbeam, thereby allowing the support surface defined by said crossbeam to be maintained at a substantially horizontal orientation when said first and second leg assemblies are placed on uneven terrain. 15. A self-stabilizing trestle that provides a stable, substantially horizontal support surface when placed on uneven terrain, comprising:a crossbeam defining the substantially horizontal support surface, having a first hinge arrangement on one side and a second hinge arrangement on the opposite side; a first leg assembly, having a first foot and a second foot, and secured at said first hinge arrangement to said crossbeam for pivoting about a first hinge axis; and a second leg assembly, having a third foot and a fourth foot, and secured to said crossbeam at said second hinge arrangement for pivoting about a second hinge axis; wherein said first hinge axis has a first hinge endpoint and a second hinge endpoint lying in a first plane; wherein said second hinge axis has a third hinge endpoint and a fourth hinge endpoint lying in a second plane; wherein said first plane and said second plane intersect below said horizontal support surface; wherein said first leg assembly has a generally tetrahedral structure with four vertices, and wherein said first hinge endpoint is a vertex, said second hinge endpoint is a vertex, said first foot is a vertex, and said second foot is a vertex; wherein said second leg assembly has a generally tetrahedral structure with four vertices, and wherein said third hinge endpoint is a vertex, said fourth hinge endpoint is a vertex, said third foot is a vertex, and said fourth foot is a vertex; and wherein said first leg assembly and said second leg assembly can pivot independently relative to said crossbeam and independently relative to one another, thereby allowing the support surface defined by said crossbeam to be maintained at a substantially horizontal orientation when said first and second leg assemblies are placed on uneven terrain. 16. The self-stabilizing trestle as recited in claim 15, wherein said first hinge axis is oriented at a predetermined acute angle relative to the support surface defined by said crossbeam, and said second hinge axis is also oriented at a predetermined acute angle relative to the support surface defined by said crossbeam.17. The self-stabilizing trestle as recited in claim 16, wherein the predetermined acute angles associated with the orientation of each hinge axis are less than approximately 44 degrees.18. The self-stabilizing trestle as recited in claim 16, wherein each foot is equipped with an independently rotating wheel.19. The self-stabilizing trestle as recited in claim 18, wherein the predetermined acute angles associated with the orientation of each hinge axis are less than approximately 80 degrees.20. The self-stabilizing trestle as recited in claim 15, wherein said first leg and second assemblies each include a spreader brace for resisting both compression and tension, such that, when the self-stabilizing trestle is placed for use, the distance between the respective feet of each leg assembly remains substantially constant.21. The self-stabilizing trestle as recited in claim 15, wherein said first hinge arrangement comprises a pair of hinges positioned on either side of said crossbeam for rotation about a first set of substantially parallel rotation axes, and said second hinge arrangement comprises another pair of hinges positioned on either side of said crossbeam for rotation about a second set of substantially parallel rotation axes.22. A self-stabilizing trestle that provides a stable, substantially horizontal support surface when placed on uneven terrain, comprising:a crossbeam having a first end and a second end, and defining the substantially horizontal support surface; a first leg assembly disposed near the first end of said crossbeam and secured to said crossbeam for pivoting about a first hinge arrangement, said first leg assembly having a pair of feet for contacting the uneven terrain, the distance between the respective feet being fixed while in use; and a second leg assembly disposed near the second end of said crossbeam and secured to said crossbeam for pivoting about a second hinge arrangement, said second leg assembly having a pair of feet for contacting the underlying terrain, the distance between the respective feet being fixed while in use; wherein, the feet of one of said leg assemblies move in a substantially vertical direction due to the placement of said trestle on the uneven terrain resulting in measurable vertical feet displacements, the feet of said one leg assembly slip across the uneven terrain in a substantially horizontal feet direction resulting in measurable horizontal displacements, thereby ensuring that the support surface defined by said crossbeam is maintained at a substantially horizontal orientation. 23. The self-stabilizing trestle as recited in claim 22,wherein said first hinge arrangement defines a first rotation axis that is oriented at a predetermined acute angle relative to the support surface defined by said crossbeam and said second hinge arrangement defines a second rotation axis that is oriented at a predetermined acute angle relative to the support surface defined by said crossbeam; wherein a slippage ratio is defined as a sum of the horizontal displacements of both of said pair of feet across said uneven terrain divided by a sum of the vertical displacements of both of said pair of feet as one of said leg assemblies rotates; and wherein the slippage ratio is substantially equal to the tangent of the predetermined acute angle at which the rotation axis of the rotating leg assembly is oriented relative to the support surface defined by said crossbeam.