Patent ID: 7171906

Claim:
A friction-drive carriage type conveyor comprising: a track including a linear path and a turning path ( 18 ); a carriage ( 1 ) so supported as to run in a running direction on and along the track; the carriage ( 1 ) having a longitudinal axis and having a frictional surface ( 6 a ) continuing linearly throughout substantially the whole length of the carriage parallel to said longitudinal axis; said frictional surface ( 6 a ) being oriented to face toward a center of an arc of the turning path and having a middle region and front and rear end portions; first friction drivers fitted aside of the linear path; the first friction drivers including a first friction drive roller ( 15 ) positioned for driving contact with the frictional surface ( 6 a ) of the carriage along said linear path; and an assembly ( 19 ) of second friction drivers fitted aside of the turning path ( 18 ) and to an inside of the arc of the turning path; the second friction driver assembly ( 19 ) comprising a plurality of second friction drive rollers ( 15 Aâ€“ 15 C) including an upstream-most drive roller ( 15 A), a downstream-most drive roller ( 15 C), and an intermediate drive roller ( 15 B), each arranged for driving contact with the frictional surface ( 6 a ) of the carriage over only a portion of a length of said frictional surface; the second friction drive rollers being adjacent to one another and spaced at intervals along the turning path ( 18 ) which are shorter than the length of the frictional surface ( 6 a ) of the carriage; wherein each of the second friction drive rollers ( 15 Aâ€“ 15 C) comes into compressive contact with the frictional surface ( 6 a ) of the carriage ( 1 ) driven forward by the just upstream adjacent friction drive roller and drives the carriage to a position where the frictional surface comes into compressive contact with at least the just downstream adjacent friction drive roller; said upstream-most drive roller ( 15 A) being positioned to engage and drive said frictional surface over only a limited portion thereof extending from said front end portion to said middle region; said intermediate drive roller ( 15 B) being positioned to engage and drive said frictional surface over only said middle region; and said downstream-most drive roller ( 15 C) being positioned to engage and drive said frictional surface over only a limited portion thereof extending from said middle region to said rear end portion.