| 摘要 |
PROBLEM TO BE SOLVED: To simply mount and remove a roller. SOLUTION: Protrusions 52 are projected from front and rear surfaces of a square groove 51 formed in a lower frame member 47 near a lower end. A roller set 54 is detachably contained in a space formed between a bottom 51a of the groove 51 and both the protrusions 52. The set 54 has a mounting member 58 and a roller 60 rotatably supported with the member 58 through a supporting shaft. Supports 58b opened down are formed at lower edges of vertical plates 58a opposed to front and rear sides of the member 58. When the set 54 is contained in the groove 51, lower ends of the plates 58a are disposed opposite to the protrusions 52 in contact relation, longitudinal movements of both shaft ends 59a of a supporting shaft are restricted by the supports 58b, received by the protrusions 52 and inhibited to be released.
|
