| CPC G01C 21/16 (2013.01) | 17 Claims |
|
1. A substrate provided for being assembled to four identical corner brackets, each corner bracket comprising a volume of matter having 3 pairs of parallel faces; each face of each pair of parallel faces comprising an opening; the openings in the faces of each pair of parallel faces being joined by a cylindrical recess having a longitudinal axis perpendicular to the faces joined by the cylindrical recess; the longitudinal axis of the cylindrical recesses being arranged such that the cylindrical recesses do not intersect each other;
the substrate having a generally square shape with edges meeting at a first and a third corners joined by a first diagonal and at a second and a fourth corners joined by a second diagonal wherein:
the first corner of the substrate has a first mounting hole, shifted clockwise from the first diagonal such that when aligning two edges of a first corner bracket of said four identical corner brackets with the two edges of the substrate meeting at said first corner, there exists a unique position of said first corner bracket where the cylindrical recess of said first corner bracket that is normal to the substrate is aligned with said first mounting hole;
the second corner of the substrate has a second mounting hole, shifted clockwise with respect to the second diagonal such that when aligning two edges of a second corner bracket of said four identical corner brackets with the two edges of the substrate meeting at said second corner, there exists a unique position of the second corner bracket, itself rotated along the normal to the substrate 90 degree clockwise with respect to the first corner bracket, where the cylindrical recess of the second corner bracket that is normal to the substrate is aligned with said second mounting hole;
the third corner of the substrate has a third mounting hole, shifted clockwise with respect to the first diagonal such that when aligning two edges of a third corner bracket of said four identical corner brackets with the two edges of the substrate meeting at said third corner, there exists a unique position of the third corner bracket, itself rotated along the normal to the substrate 90 degree clockwise with respect to the second corner bracket, where the cylindrical recess of the third corner bracket that is normal to the substrate is aligned with said third mounting hole;
the fourth corner of the substrate has a fourth mounting hole, shifted clockwise with respect to the second diagonal such that when aligning two edges of a fourth corner bracket of said four identical corner brackets with the two edges of the substrate meeting at said fourth corner, there exists a unique position of the fourth corner bracket, itself rotated along the normal to the substrate 90 degree clockwise with respect to the third corner bracket, where the cylindrical recess of the fourth corner bracket that is normal to the substrate is aligned with said fourth mounting hole.
|