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A telescopic mast system has a base tube, a plurality of axially movable coaxial inner tubes nestable successively within each other and within the base tube, and a winch supported at the lower end of the base tube with a pair of preferably wire ropes driven thereby for extending and retracting the

A telescopic mast system has a base tube, a plurality of axially movable coaxial inner tubes nestable successively within each other and within the base tube, and a winch supported at the lower end of the base tube with a pair of preferably wire ropes driven thereby for extending and retracting the inner tubes. The base and inner tubes have collars at their respective ends, the collars of adjacent tubes engaging each other to limit extension thereof and to provide additional structural support during application of bending loads on the mast system. The ropes are connected to pulleys mounted near or within tube collars so that the ropes and pulleys are totally enclosed within the mast system. As the winch is rotated in one direction, the ropes axially move the inner tubes from a nested or stowed position within the base tube to a fully vertically extended operational position. When the winch is rotated in the opposite direction, the ropes apply a positive retractive force to the inner tubes and return them to the fully nested stowed position.

대표청구항 ▼

An extendible and retractable telescopic mast system comprising: a base for supporting said mast system; a plurality of elongated tubes having aligned longitudinal axes and successively decreasing transverse dimensions to permit each of said tubes to axially slide therebetween, said tubes comprising

An extendible and retractable telescopic mast system comprising: a base for supporting said mast system; a plurality of elongated tubes having aligned longitudinal axes and successively decreasing transverse dimensions to permit each of said tubes to axially slide therebetween, said tubes comprising: a base tube having the largest transverse dimension and being secured to said base, said base tube having an upper portion and a lower portion; an innermost tube with the smallest transverse dimension having a lower portion; and at least one intermediate tube positioned between the innermost and base tubes and having an upper portion and a lower portion, said intermediate and innermost tubes being axially movble relative to said base tube and to each other; means for so axially moving said innermost and intermediate tubes, comprising: winch means in close proximity to said base tube and having a capstan with a rope wound thereon, said rope having two lengths extending from opposite ends, respectively of said capstan; first pulley means mounted on the upper portion of said base tube; second and third pulley means mounted on the lower and upper portions, respectively, of said intermediate tube; one of said rope lengths extending from said capstan to and around, in succession, said first pulley means and said second and third pulley means of the respective intermediate tubes, the ends of both of said rope lengths being connected to said innermost tube; said winch means having motor means for selectively rotating said capstan in opposite directions for extending and retracting said intermediate and innermost tubes.