Rail supported articulated climbing dolly

Claim 1

A climbing dolly system, comprising: a normally horizontal platform having forward and rearward ends; frame means including an axle underlying and depending upon respective end portions of said platforms; at least one of said frame means being pivotally connectd with the platform for horiozntal pivoting movement about a vertical axis; each said frame means including at least one transverse frame member having at least one wheel strut depending from its respective ends; tongue and handle means connected with said one frame means for manual steering movement of said dolly on a horizontal surface; wheels journalled by said axles for supporting respective end portions of said platform in a mobile manner when on a horizontal surface; track means including a pair of box channel tracks disposed in spaced parallel relation extending in a fixed position between vertically spaced horizontal support surfaces for supporting the dolly during movement from one elevation to another; roller means moveable on said track means including two pairs of rollers connected with the depending end portion of each said wheel strut in forward to rearward aligned spaced relation adjacent the respective wheel and spaced upwardly with respect to a horizontal surface supporting the wheels, the rollers of each pair of said pair of rollers being juxtaposed transversely of the dolly platform; a pulley block secured to one end portion of the track means; and, which means mounted on the track means and having a flexible element entrained through the pulley block for moving the dolly along the track means.