Patent ID: 7686716

Claim:
A drive sprocket wheel slide restricting structure for a bicycle transmission comprising a drive sprocket wheel which is driven by a drive shaft, a driven sprocket wheel body which includes a plurality of driven sprocket wheels and is operatively connected with the drive sprocket wheel by an endless chain, and a derailleur which changes over the winding of the endless chain among the plurality of driven sprocket wheels of the driven sprocket wheel body, comprising: a slide member, which is movable in an axial direction of the drive shaft, provided between the drive shaft and the drive sprocket wheel; a drive sprocket wheel position setting member integrally mounted on an arm of the derailleur at a position where the drive sprocket wheel position setting member overlaps the drive sprocket wheel as viewed in the axial direction of the drive shaft; and a drive sprocket wheel movement restricting member provided for moving in the axial direction of the drive shaft together with the drive sprocket wheel, wherein the drive sprocket wheel position setting member is integrally formed with the derailleur arm whose axial position is set by the derailleur, the drive sprocket wheel movement restricting member is integrally mounted on a right side of the drive sprocket wheel, and the drive sprocket wheel position setting member is positioned between the drive sprocket wheel and the drive sprocket wheel movement restricting member such that when the drive sprocket wheel and the drive sprocket wheel movement restricting member are made to move leftwardly, the drive sprocket wheel movement restricting member is brought into contact with the drive sprocket wheel position setting member to obstruct the leftward movement of the drive sprocket wheel and the drive sprocket wheel movement restricting member, and when the drive sprocket wheel and the drive sprocket wheel movement restricting member are made to move rightwardly, chain guide members which are integrally formed with the drive sprocket wheel are brought into contact with the drive sprocket wheel position setting member to obstruct the rightward movement of the drive sprocket wheel and the drive sprocket wheel movement restricting member.