Patent ID: 7484615

Claim:
A stopper cylinder for stopping a workpiece at a predetermined position when said workpiece abuts against a roller and retaining a lever at the predetermined position, said workpiece being transported in a predetermined direction, wherein said roller is rotatably supported by said lever, said stopper cylinder comprising: a main cylinder body; a lever holder disposed on an upper side of said main cylinder body, said lever holder rotatably supporting said lever through a predetermined angle; a lock pin disposed on a side surface portion of said lever; a lock mechanism comprising a first rotary member rotatably supported on a side surface portion of said lever holder, a second rotary member rotatably supported with respect to said first rotary member and having an engaging section for engaging said lock pin, and a spring interposed between said first rotary member and said second rotary member, said spring regulating a rotary action of said lever; and an unlocking section disposed on said first rotary member, which releases said lever from a locked state effected by said lock mechanism by rotating said first rotary member, wherein said spring produces a repulsive force such that said engaging section is urged toward said lock pin when said lock pin engages with said lock mechanism, and wherein said second rotary member is rotationally displaced by said lock pin against the repulsive force of said spring in accordance with rotation of said lever when an external force is applied to said lever in a direction opposite to the transport direction of said workpiece.