| 摘要 |
PROBLEM TO BE SOLVED: To reduce as far as possible an uneven speed of a toothed belt 8 of a toothed belt drive unit used for office equipment such as a printer, a copier and the like, and to improve printing accuracy and quality of a picture of office equipment. SOLUTION: A belt tooth portion 11 comprises tooth dedendum portions 12 and 12 formed from arc faces arranged symmetrical to a central line C2 in the tooth-width direction, tooth flank portions 13 and 13 formed from convex arc faces arranged symmetrical to the central line C2 in the tooth-width direction in succession with the tooth dedendum portions 12 and 12, and a tooth addendum portion 17 formed from an arc face that is successively connected with both tooth flank portions and that has a central point O2B on the central line C2 in the tooth-width direction. The tooth addendum portion 17 is located in the vicinity of the tip of the belt tooth portion 11 so that the belt tooth portion 11 is arranged to be approximately a triangle shape.
|
