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US3730475A Expired / Lapsed US ⏱️ 0.0 years remaining

Form for casting concrete building foundation

Assignee: Individual
•
Filing: 1970-09-23
•
Granted: 1973-05-01
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Expires: 1990-09-23
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Abstract

Abstract A form unit comprising two spaced apart and opposed downwardly diverging walls interconnected at their top and bottom edges, but unconnected at their end edges so that the unit is open-ended and a plurality of such form units may be arranged end-to-end to produce a form of any desired length. The unit has a relatively wide footing-producing lower region, and each wall has a strengthening rib which may continue into a handle serving as the top connection between the walls. The bottom connection is removable, so that it remains in the hardened concrete when the form is lifted off, and may serve to support reinforcing rods.

Inventors

  • 👤 L Werfel
  • 👤 H Berg

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 15:21
CPC Classifications
E; E02; E02D; E02D27/00; E02D27/01; E02D27/02; B; B28; B28B; B28B7/00; B28B7/0029; B28B7/0035; B28B7/0038

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 139 words
A form unit for casting a concrete building foundation in situ comprising two spaced apart and opposed downwardly diverging walls, each of said walls being provided with at least one strengthening rib extending in a direction from its upper edge to its lower edge, said strengthening rib being on the outer surface of each wall, and a depression in the inner surface of each wall adapted to accommodate a rib of another form unit when the units are nested, means interconnecting said walls at their upper edges, and means interconnecting said walls at their lower edges, the end edges of said walls being unconnected to each other so that the form unit is open ended, whereby a plurality of said form units may be arranged end-toend to produce a form for casting a foundation wall of any desired length.
Claim 2
Dependent Claim 139 words
A form unit for casting a concrete building foundation in situ comprising two spaced apart and opposed downwardly diverging walls, each of said walls being provided with at least one strengthening rib extending in a direction from its upper edge to its lower edge, said strengthening rib being on the outer surface of each wall, and a depression in the inner surface of each wall adapted to accommodate a rib of another form unit when the units are nested, means interconnecting said walls at their upper edges, and means interconnecting said walls at their lower edges, the end edges of said walls being unconnected to each other so that the form unit is open ended, whereby a plurality of said form units may be arranged end-toend to produce a form for casting a foundation wall of any desired length.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-04-30 1976-10-30 1977-05-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-04-30 1980-10-30 1981-05-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-04-30 1984-10-30 1985-05-01 $7700.00 Window Closed / Lapsed

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