Patent US3844527A successfully refreshed from Google Patents.
US3844527A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water reservoir liner for concrete forms
Assignee: Individual
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Filing: 1973-09-06
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Granted: 1974-10-29
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Expires: 1993-09-06
Abstract
Abstract A liner for concrete forms comprises a self-skinning, flexible foam of elastomeric material formed into sheets for lining a concrete form. The liner includes at least one dense but permeable concrete contacting face or skin leaving its configuration in the set concrete, and an open cell foam core which takes up water and air passing through the contacting skin into the foam from the surface of freshly poured concrete, particularly on vibration of the concrete. Water and air separate in the foam core with the air passing upwardly and out of the core, leaving a reservoir of water in the open cells of the core, thereby maintaining a wet surface on the contacting face of the concrete, and which water migrates back into the concrete as it cures, taking up water.
Inventors
- 👤 S Scott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:11
CPC Classifications
E; E04; E04G; E04G9/00; E04G9/10; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/249981
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
168 words
In combination with smooth surfaced panels for concrete forms for making structural members, a liner comprising an independently formed sheet of soft, flexible, resilient elastomeric, synthetic polymer having an open cell foam core and front and rear skins of dense, tough, abrasion resistant polymer and at least said front skin containing microscopic pores capable of passing air and water but not the matrix and fines of a concrete mix; said rear skin being smooth and said front skin having a concrete contacting face formed as a negative mold of a desired pattern; said liner being at least about 1/8 inch thick at its thinnest section; said core having a density of about 3-10 pounds per cubic foot, a tensile strength of 40-150 pounds per square foot, a tear strength Die C of 2-30 pounds per linear inch, and the skin has a Shore A hardness of 20-90 and ultimate elongation of 75-200 percent, a tear strength Die C of 50-200 pounds per linear inch, and high abrasion resistance.
Claim 2
Dependent Claim
168 words
In combination with smooth surfaced panels for concrete forms for making structural members, a liner comprising an independently formed sheet of soft, flexible, resilient elastomeric, synthetic polymer having an open cell foam core and front and rear skins of dense, tough, abrasion resistant polymer and at least said front skin containing microscopic pores capable of passing air and water but not the matrix and fines of a concrete mix; said rear skin being smooth and said front skin having a concrete contacting face formed as a negative mold of a desired pattern; said liner being at least about 1/8 inch thick at its thinnest section; said core having a density of about 3-10 pounds per cubic foot, a tensile strength of 40-150 pounds per square foot, a tear strength Die C of 2-30 pounds per linear inch, and the skin has a Shore A hardness of 20-90 and ultimate elongation of 75-200 percent, a tear strength Die C of 50-200 pounds per linear inch, and high abrasion resistance.
Claim 3
Dependent Claim
16 words
The combination of claim 1 wherein said front and rear skins on said core is integral.
Claim 4
Dependent Claim
24 words
The combination of claim 2 wherein said front and rear skins are of the same material as said core and is formed integrally therewith.
Claim 5
Dependent Claim
13 words
The combination of claim 1 wherein said rear skin includes a backing member.
Claim 6
Dependent Claim
22 words
The combination of claim 1 wherein said liner is sufficiently soft to seal against an adjoining liner to form a seamless joint.
Claim 7
Dependent Claim
12 words
The combination of claim 1 wherein said synthetic polymer is a polyurethane.
Claim 8
Dependent Claim
30 words
The combination of claim 1 wherein said core has sufficient open cells to permit the separation of air and water therein, and permit air to pass upwardly through said core.
References Cited (Backward Citations)
US3427178A
Cited
US3694530A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |