Patents Assigned to Tanaka Shikan Co., Ltd.
  • Patent number: 5639175
    Abstract: A threaded paper tube includes a multiple paper tube having an inner tube with spiral ridges on its outer surface, and an outer tube and a tightening robe each having grooves on their inner surfaces which are in the same pitch as the spiral ridges. The total length of the threaded paper tube may be changed by adjusting the screwing extent between the inner and outer tubes, and the total length may then be fixed by tightening the tightening tube against the outer tube. The ridges and grooves are provided as steps formed on the inner tube's outer surface, the outer tube's inner surface and the tightening tube's inner surface using a ribbon-like shaped paper material which is adhered and fixed at the same pitch on the surfaces of the tubes.
    Type: Grant
    Filed: March 21, 1996
    Date of Patent: June 17, 1997
    Assignee: Tanaka Shikan Co., Ltd.
    Inventor: Ryuichi Emoto