Patent US3862736A successfully refreshed from Google Patents.
US3862736A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for forming polygonal voids in concrete members
Assignee: Dearborn Rubber Corp
•
Filing: 1973-01-04
•
Granted: 1975-01-28
•
Expires: 1993-01-04
Abstract
Abstract A device for forming polygonal voids in concrete members, such as concrete beams, slabs and the like, includes an elongated, hollow, tubular body formed of a fabric reinforced, elastomeric material. The body maintains a cloverleaf or cross shape having a first predetermined, cross-sectional area when unpressurized and inflates to and maintains, without the necessity for any additional support, a square, rectangular or other polygonal shape having a second cross-sectional area greater than the first cross-sectional area. The device includes a novel end portion configuration that utilizes the tensile strength of the fabric reinforced, elastomeric, tubular body to integrally remove the end portion and the tubular body from a polygonal void formed in a concrete member.
Inventors
- 👤 Richard E Herro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 03:22
CPC Classifications
B; B28; B28B; B28B7/00; B28B7/28; B28B7/30; B28B7/32; Y; Y10; Y10S; Y10S425/00; Y10S425/014
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
102 words
A core for use in casting hollow concrete members comprising a first, elongated, inflatable body formed of at least two elastomeric layers separated by a double layer of reinforcing fabric, means for sealing the ends of said first body, and means for admitting a pressurized medium to the interior of said first body, said first body in its unpressurized condition having a substantially cloverleaf shape of a first cross-sectional area and in its pressurized condition being capable of maintaining a substantially polygonal shape of a second cross-sectional area substantially greater than said first cross-sectional area without the necessity of any additional support.
Claim 2
Dependent Claim
102 words
A core for use in casting hollow concrete members comprising a first, elongated, inflatable body formed of at least two elastomeric layers separated by a double layer of reinforcing fabric, means for sealing the ends of said first body, and means for admitting a pressurized medium to the interior of said first body, said first body in its unpressurized condition having a substantially cloverleaf shape of a first cross-sectional area and in its pressurized condition being capable of maintaining a substantially polygonal shape of a second cross-sectional area substantially greater than said first cross-sectional area without the necessity of any additional support.
Claim 3
Dependent Claim
66 words
A core as defined in claim 1 wherein at least one of said sealing means comprises a second body formed of elastomeric material and having said cloverleaf shape, said second body being integrally connected by curing to at least an end portion of said first body, said end portion extending in a direction substantially transverse to the direction of the longitudinal axis of said first body.
Claim 4
Dependent Claim
15 words
A core as defined in claim 1 wherein said polygonal shape comprises a square shape.
Claim 5
Dependent Claim
28 words
A core as defined in claim 1 wherein said cloverleaf shape is formed by said first body having a plurality of corners separated by greatly recessed side portions.
Claim 6
Dependent Claim
55 words
A core as defined in claim 4 wherein the ratio of the distance between the most greatly separated sections of two, opposite ones of said recessed side portions to the distance between the most recessed sections of said two, opposite ones of said recessed side portions is in the range of from 1.50:1 to 3.00:1.
Claim 7
Dependent Claim
13 words
A core as defined in claim 5 wherein said ratio is approximately 1.92:1.
Claim 8
Dependent Claim
66 words
A core as defined in claim 4 wherein the ratio of the distance between the most greatly separated sections of two opposite ones of said recessed side portions of said first body in its unpressurized condition to the distance between the most greatly separated sections of said two, opposite ones of said recessed side portions of said first body in its pressurized condition is approximately 0.853:1.
Claim 9
Dependent Claim
32 words
A core as defined in claim 1 wherein said first body comprises an integrally cured sandwich structure including three sheets or layers of elastomeric material separated and reinforced by two fabric means.
References Cited (Backward Citations)
US1570915A
Cited
US2324554A
Cited
US3229437A
Cited
US3072995A
Cited
US3270111A
Cited
US3428288A
Cited
US3629030A
Cited
US3641230A
Cited
US3648963A
Cited
US3677688A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-27 | 1978-07-29 | 1979-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-27 | 1982-07-29 | 1983-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-27 | 1986-07-29 | 1987-01-28 | $7700.00 | Window Closed / Lapsed |