Friction-drive carriage type conveyor

Abstract

A friction-drive carriage type conveyor includes a carriageso supported as to run in a running direction along a track, which includes a linear path and a turning path. The carriagehas a frictional surfacecontinuing linearly along its whole length. The conveyor is fitted with first friction drive rollersfor contact with the frictional surface, which are positioned near the linear path. The conveyor is also fitted with second friction drive rollersA–C for driving the carriagesmoothly and reliably even along the turning path. The second friction drive rollersA–C are spaced at intervals along the turning path, which are shorter than the frictional surface. The second friction drive rollersA–C are so supported that each of them can move between an advance limit position and a retraction limit position. The advance limit position is on the locus described by the frictional surfacewhen the carriagepasses along the turning path. The retraction limit position is outside the locus. Each of the second friction drive rollersA–C can be biased toward the associated advance limit position by a biasing means, which may be a hydraulic cylinder. Each of the second friction drive rollersA–C comes into compressive contact with the frictional surfaceof the carriagedriven forward by the just upward friction drive roller and drives the carriage to a position where the frictional surface comes into compressive contact with at least the just downstream friction drive roller.