发明名称 |
Freeze-resistant plastic pipe and method for its manufacture |
摘要 |
A plastic pipe with a hard outer shell lined with an inner shell of soft resilient plastic foam with a smooth central axial passageway adapted to be a conduit for liquid. A method of manufacturing this pipe which comprises simultaneously extruding the material for the outer shell and the foamable material for the inner shell into a pipe forming die.
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申请公布号 |
US4773448(A) |
申请公布日期 |
1988.09.27 |
申请号 |
US19870019416 |
申请日期 |
1987.02.26 |
申请人 |
FRANCIS, NORMAN L. |
发明人 |
FRANCIS, NORMAN L. |
分类号 |
B29C44/22;B29C47/06;B29C47/88;E03B7/10;F16L9/12;(IPC1-7):E03B7/10;B29C67/22;B29C47/26 |
主分类号 |
B29C44/22 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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