Patents Assigned to Takushoku University
  • Patent number: 6131431
    Abstract: There is disclosed a pipe member rolled up as a coil and roll-formed, the pipe member made of material having a spring-back characteristics and having a specific residual stress distribution existing along a direction perpendicular to the rolling-up direction of said pipe member, the specific residual stress distribution being formed by being wounded around a longitudinal direction thereof by roll-forming, and when the member is unfurled out, two longitudinal edge portions of the member being overlapped to each other thus forming a pipe shape.
    Type: Grant
    Filed: March 27, 1998
    Date of Patent: October 17, 2000
    Assignee: Takushoku University
    Inventor: Hiroshi Ona