Patent ID: 8905623
Filing Date: 2014-12-09
Classification: B29B,B29C

Abstract:
1. A two-shaft extruder comprising: a pair of rotor shafts rotatably disposed with a distance therebetween diminishing toward the leading ends thereof; and a screw blade mounted to the leading end of each one of the pair of rotor shafts, one screw blade intruding into the pitch of the other screw blade; and a drive unit mounted the base end of each one of the pair of rotor shafts for rotatably driving the rotor shaft associated therewith without the use of conical gears for synchronizing the drive of the pair of rotor shafts; wherein there is provided a screw blade contact preventing mechanism configured to allow a predetermined phase difference between the pair of rotor shafts, while inhibiting a phase difference greater than the predetermined phase difference when the pair of rotor shafts are rotatably driven respectively, wherein said screw blade contact preventing mechanism includes: a first abutment member comprised of a plurality of projecting portions formed in one rotor shaft along the peripheral direction thereof and equidistantly or substantially equidistantly from each other; and a second abutment member comprised of a plurality of projecting portions formed in the other rotor shaft along the peripheral direction thereof and equidistantly or substantially equidistantly from each other; a path of the projecting portions of the first abutment member and a path of the projecting portions of the second abutment member are configured to interfere with each other; and between a projecting portion of the first abutment member and a projecting portion of the second abutment member peripherally opposed thereto, there is provided a gap for allowing the predetermined phase difference between the pair of rotor shafts, while inhibiting a phase difference greater than the predetermined phase difference.