Patent ID: 11383427

Abstract:
Both diameter expansion and contraction control and fitting stabilization are achieved at the same time in a pipe end release-type pipe-forming apparatus having a non-inner periphery restriction structure. A driving part (10) provided in an apparatus frame (30) of a pipe-forming apparatus (3N) presses an unformed following strip portion (92) of the strip member (90). A reverse side guide portion (83) is engaged with a pipe end portion (91e) of a preceding spiral pipe portion (91) from a reverse side. A face side guide portion (82) is engaged with the pipe end portion (91e) from a face side. The face side guide portion (82) is shifted to the propulsion rear side beyond the reverse side guide portion (83). The following strip portion (92) is extruded from the driving part (10) toward an inter-guide clearance (84) between the reverse side guide portion (83) and the face side guide portion (82). Preferably, the driving part (10) is position-adjustably attached to the guide portions (83), (82) or the apparatus frame (30) via a position adjustment mechanism (31a).