Overhead service unit

An overhead service unit, comprising a base, a first frame fixedly mounted on said base and projecting upwardly therefrom, a plurality of second frames slidably interconnected to each other and to said first frame, a platform movably mounted on one of said second frames, a pair of cylinders mounted on said base and each having an upwardly projecting vertically movable ram, an axle mounted on each of said rams for movement therewith, guide means mounted on said first frame, slide means mounted on said axles and engageable with said guide means for guiding the movements of said axles, a plurality of sprockets mounted on said axles and first and second frames, and a plurality of chains connected to said base, first frame, one of said second frames and platform and received on said sprockets whereby actuation of said cylinders to extend one of said rams and retract the other of said rams will cause said rams to move said axles in opposite directions and cause said chains to move said frames and platform vertically with and with respect to each other.

An overhead service unit, comprising a base, a first frame fixedly mounted on said base and projecting upwardly therefrom, a plurality of second frames slidably interconnected to each other and to one side of said first frame, a pair of vertically extending tracks mounted on one of said second frames at the side of said second frames opposite said first frame, a platform, a plurality of rollers mounted on said platform and carried in said tracks for supporting said platform in said tracks, a pair of cylinders mounted on said base and each haing an upwardly projecting vertically movable ram, a plurality of sets of chains operatively connected to said base, first and second frames, platform and rams whereby upon actuation of said cylinders to extend one of said rams and retract the other of said rams said chains will cause said second frames and platform to move vertically with and with respect to each other, and means for selectively actuating said cylinders to move said rams with respect to each other.

A platform assembly, comprising a base, a first frame fixedly mounted on said base and projecting upwardly therefrom, a plurality of second frames slidably interconnected to each other and to said first frame, a platform slidably connected to one of said second frames and projecting outwardly therefrom, a pair of cylinders mounted on said base in longitudinally spaced relationship and each having an upwardly projecting vertically movable ram, an axle connected to each of said rams, pairs of laterally spaced guides interconnected to said first frame, slides mounted on the ends of said axles and slidably received on said guides, a plurality of sprockets mounted on said axles, and first and second frames, and a plurality of chains operatively connected to first and second frames, platform and base and received over said sprockets whereby upon actuation of said cylinders to extend one of said rams and retract the other of said rams said chains will cause said second frames and platform to move vertically with respect to each other.

An overhead service unit, comprising a base, a first frame fixedly mounted on said base and projecting upwardly therefrom, a plurality of second frames slidably interconnected to each other, one of said second frames being slidably connected to said first frame, a platform movably supported on another of said second frames and projecting outwardly therefrom, first chain means connected to said first frame and platform and operatively connected to said second frames, second chain means connected to said base and said one of said second frames, third chain means connected to said first frame and said other of said second frames and operatively connected to said one of said second frames, and means for moving said first and second chain means to cause said first, second and third chain means to move said platform and second frames vertically with and with respect to each other.