| 摘要 |
PROBLEM TO BE SOLVED: To enable reverse rotation in a scraping device including a chain drive device of a notch-drive pin driving type.SOLUTION: A link constituting a chain has a notch on a side opposing to a driving wheel, and a space at least opened on a side opposing to a driving wheel is formed between plate-like portions 38 of the link, so as to enable access to a barrel. The driving wheel 4 includes drive pins 62 and tooth parts (sprocket parts) 60A arranged at intervals each corresponding to a pitch of the link. During normal rotation, the drive pin 62 of the driving wheel 4 engages with the notch 50 of the chain 8 on a first engagement surface 50-1 and the tooth part 60A engages with the barrel 44 at a first edge 60A-1. By both of the engagement of the drive pin with the notch and the engagement of the tooth part with the barrel, driving of the chain 8 is performed. During reverse rotation, the drive pin 62 engages with the notch 50 of the chain 8 on the first engagement surface 50-1 and by the single engagement of the drive pin with the notch, driving of the chain is performed. |
