发明名称 |
Method and device for the performance of a supporting function in a passage |
摘要 |
A device for the performance of a supporting function in a passage includes a resilient plug which is expandible to the cross-sectional area of the passage and contractible to a lesser cross-sectional area. Contraction of the plug after its supporting function has been completed permits the plug to be readily withdrawn from the passage. The device is particularly useful for forming a passage in an element composed of a flowable and hardenable material such as concrete. The material is poured around the plug and the plug is contracted and withdrawn from the material once this has hardened.
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申请公布号 |
US4437276(A) |
申请公布日期 |
1984.03.20 |
申请号 |
US19810307082 |
申请日期 |
1981.09.29 |
申请人 |
GOLDBERG, JURGEN |
发明人 |
GOLDBERG, JURGEN |
分类号 |
E04G21/16;B28B7/16;B28B7/30;B28B23/00;B66C1/62;B66C1/66;E04G15/04;E04G15/06;(IPC1-7):E04B1/41 |
主分类号 |
E04G21/16 |
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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