Patent ID: 7093543

Claim:
A friction-drive carriage type conveyor comprising: a track, the track being traversed by a passage ( 26 ) of predetermined width to thereby have two track sections, one side track section bound for the passage the other side extending downstream from the passage; a carriage ( 1 ) having a length greater than the width of said passage and so supported as to run in a running direction along the track; the carriage ( 1 ) including casters ( 3 ) for rolling on the track and supporting the carriage; the carriage ( 1 ) having a frictional surface ( 10 a ) extending in the running direction; friction drivers ( 16 ) arranged on a side of the track for contacting with the frictional surface ( 10 a ) to drive the carriage ( 1 ) along the track; a main guide rail ( 14 ) lying on the whole length of both the track sections except for the passage ( 26 ) which has no main rail; a rear auxiliary guide rail ( 31 ) lying on the track section bound for the passage ( 26 ) and spaced laterally from said main guide rail ( 14 ); and a front auxiliary guide rail ( 32 ) lying on the track section extending downstream from the passage ( 26 ) and spaced laterally from said main guide rail ( 14 ); the carriage ( 1 ) further including a pair of main guided members ( 4 , 5 ) mounted in fixed relation to the carriage and engageable with the main guide rail ( 14 ), the main guided members being positioned along a first axis of the carriage extending in the running direction and spaced from each other along said axis by a distance shorter than the width of the passage ( 26 ) such that both of said main guided members ( 4 , 5 ) are disengaged from said main guide rail ( 14 ) during a period while said carriage is traversing said passage ( 26 ); the carriage ( 1 ) further including a pair of front auxiliary guided members ( 6 , 7 ) mounted in fixed relation to the carriage, spaced laterally from said first axis and engageable with the front auxiliary guide rail ( 32 ), the front auxiliary guided members being spaced from each other in the running direction and being positioned in front of the main guided members ( 4 , 5 ); the carriage ( 1 ) further including a pair of rear auxiliary guided members ( 8 , 9 ) mounted in fixed relation to the carriage, spaced laterally from said first axis and engageable with the rear auxiliary guide rail ( 31 ), the rear auxiliary guided members being spaced from each other in the running direction and being positioned in back of the main guided members ( 4 , 5 ); a distance between a forwardmost front auxiliary guided member and a rearwardmost rear auxiliary guided member being greater than the width of said passage ( 26 ); wherein, while the carriage ( 1 ) is caused to move over the passage ( 26 ), at least two of the guided members ( 4 – 9 ) at all times engage with the associated guide rails ( 14 , 31 , 32 ).