Convertible rail-highway maintenance vehicle

Claim 1

A convertible highway/rail tamper, comprising: a chassis; an engine on said chassis; front and rear highway wheels; suspension means mounting said highway wheels on said chassis for limited movement relative to the chassis; front and rear rail wheels, said front rail wheels being mounted on said chassis for movement between a retracted position when the vehicle is in a highway going condition and an extended position for engaging track rails when the vehicle is in a rail going condition; a turntable-jacking means movable mounted on said chassis for movement from a normally retracted position to an extended position for supporting the vehicle with said highway wheels spaced above the track rails during transfer between a highway and track rails; slides fixed to said chassis; a sub-frame vertically slidable on said slides, said sub-frame carrying for sliding movement therewith tamping apparatus which includes two jacks disposed on respective sides of said chassis, each jack having a jack body fixed to said sub-frame and a foot extendable from said jack body, said rear rail wheels also being mounted on said sub-frame for sliding movement therewith so as to be movable, when said chassis is supported on said turntable jacking means and said feet have been extended into the engagement with ground beside the track rails, from a retracted position to an extended position only by sliding movement of said sub-frame down said slides on relative retraction of the bodies and feet thereof, said front and rear rail wheels when moved to the extended position supporting the vehicle in the rail going condition in which the highway wheels are out of contact with the track rails; and first and second drive means connected to said engine and at least some of said highway wheels and at least some of said rail wheels and selectively engageable for transmitting power from the engine to at least some of the highway wheels and to at least some of the rails wheels.