Adjustable stand

An adjustable stand for supporting heavy loads at various heights, said stand comprising:

• a platform comprising four channel shaped beam members rigidly fastened together in a generally rectangular configuration and having upper surfaces all disposed in a common plane to provide a flat supporting surface, two of said beam members being relatively long and extending longitudinally of said platform, the spaced side walls of said longitudinally extending channel shaped beam members extending downwardly and each having longitudinally spaced notches extending inwardly from the lower edges thereof,
• two pairs of legs disposed adjacent opposite sides of said platform and formed of beams of generally rectangular cross-section, the legs of each pair being pivotally secured together adjacent the longitudinal midpoints thereof, the upper end of a first leg of each pair extending between the downwardly extending side walls of the adjacent longitudinally extending beam member of said platform and being pivotally secured thereto, the upper ends of the other legs of said pairs being joined by a rod member of a cross-sectional configuration such as to fit within pairs of said spaced notches, the height of said platform being dependent upon the location of the pair of notches in which said rod member is placed,
• a pair of longitudinally extending base members of substantially the same length as the longitudinally extending beam members of said platform, said base members being formed of channel shaped members with upturned walls extending upwardly from the supporting surface, said upturned walls being spaced apart a distance at least as great as the width of the first legs of each pair of legs, the bottoms of such first legs being disposed between said upturned walls in slidable engagement with the bottom wall of the channel and the lower ends of the other legs of said pairs being pivotally secured to the side walls of said channels and of a length to engage a supporting surface, and
• resilient means biasing said legs towards a position in which said platform is at its maximum height to tend to counterbalance the weight of said platform and said legs and hence facilitating the vertical adjustment of said stand.