Multi-layer plastic hollow pipe
AssigneeExcell Corporation
InventorsTatsuya Nakagawa, Yasuo Ezaki
Life of this patent
Estimating the term…
Abstract
A multi-layered plastic pipe particularly suitable for use as an intake manifold of an internal combustion engine is provided. The present pipe includes a hollow plastic core, at least one spacer member provided on the hollow plastic core and an outer layer integrally provided on the outer peripheral surface of the hollow plastic core excepting the spacer member. The spacer member is preferably formed from a plastic material, and the outer layer is also formed from a plastic material. There is also provided a method for manufacturing a multi-layered plastic pipe using a spacer member to prevent a hollow plastic core placed in a mold cavity from being deformed when a molted plastic material is supplied into the mold cavity under pressure.
Claims14
A multi-layered plastic pipe, comprising:
- a blow molded hollow member formed in a predetermined shape from a first plastic material;
- a plurality of isolated spacer members each provided in the form of an isolated projection, having side peripheries, the projections being at multiple predetermined selected places spaced longitudinally on an outer peripheral surface of said blow molded hollow member, said spacer members having a predetermined height and being formed from a second plastic material;
- an outer layer integrally formed from a third plastic material on said outer peripheral surface of said blow molded hollow member and surrounding the entire side peripheries of said spacer members;
- and
- wherein said spacer members are located at the multiple predetermined selected places to define a means for counteracting a force applied to said blow molded hollow member in a direction transverse to a longitudinal axis of said blow molded hollow member when the third plastic material is formed on said blow molded hollow member.
A multi-layered plastic pipe, comprising:
- a blow molded hollow member formed in a predetermined shape from a first plastic material;
- a plurality of isolated spacer members each integrally formed on the blow molded hollow member and provided in the form of an isolated projection, having side peripheries, the projections being at multiple predetermined selected places spaced longitudinally on an outer peripheral surface of said blow molded hollow member, said spacer members having a predetermined height and being formed from a second plastic material;
- an outer layer integrally formed from a third plastic material on said outer peripheral surface of said blow molded hollow member and surrounding the entire side peripheries of said spacer members, said outer layer having end flanges and having a thickness between said end flanges substantially equal to the height of the spacer members;
- and
- wherein said spacer members are located at the multiple predetermined selected places on said blow molded hollow member to define a means for determining the thickness of the outer layer between said end flanges.
Dependencies are inferred from the claim text.