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Insert means for forming voids in concrete and method of applying same

  • US 4,515,271 A
  • Filed: 11/17/1983
  • Issued: 05/07/1985
  • Est. Priority Date: 09/20/1982
  • Status: Expired due to Term
First Claim
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1. Insert means for use in forming voids in poured concrete comprising a tubular body of sheet material insertable in poured concrete while the concrete is in a plastic state, upper and lower closure elements detachably secured in top and bottom portions of the tubular body, the inner surface of the tubular body being formed with a helical line of scoring extending between the upper and lower closure elements, said upper closure element being formed integrally with the tubular sheet material and constructed at an upper side thereof with upperwardly extending holder tab means for lifting the upper closure element and also pulling away the tubular structure along the said line of scoring to leave a void in hardened concrete.

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