| 摘要 |
PROBLEM TO BE SOLVED: To provide a chain structure which is simple and capable of preventing other parts in the chain structure from being damaged because a chain disengages from sprocket wheel teeth owing to a big wave force and consequently a chain or flight plate drops.SOLUTION: A chain structure 40 includes a chain 42 and a sprocket wheel 6 having a plurality of teeth engageable with the chain 42 on a periphery thereof, wherein the chain connects a plurality of sets of mutually opposite side plate members 18, 20 and 44 endlessly in a longitudinal direction and engages with peripheral teeth 6c of the sprocket wheel 6. In addition, a drop preventing means 50 for preventing disengagement from an engaging condition with sprocket wheels 6, 8, 10 and 12 is arranged in at least one member 44 out of the plurality of sets of side plate members. |
