US4535579A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Roof ballast block
Assignee: Norstar Bank of Upstate NY
•
Filing: 1983-08-05
•
Granted: 1985-08-20
•
Expires: 2003-08-05
Abstract
Abstract A roof ballast block having generally rectangular top and bottom faces and two parallel edges bevelled at substantially identical angles of 12° to 23° from the vertical, the remaining two edges being substantially vertical, the block having a plurality of parallel spaced channels in its bottom face and being characterized by a density of 85 to 155 pounds per cubic foot, a compressive strength of at least 2500 psi, a flexure strength of at least 300 psi, and a capability of undergoing at least 100 freeze-thaw cycles without cracking.
Inventors
- 👤 John V. Burgoyne
- 👤 Thomas E. Phalen, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:21
CPC Classifications
E; E04; E04D; E04D11/00; E04D11/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
94 words
A roof ballast block having generally rectangular top and bottom faces, and two parallel edge faces bevelled at substantially identical angles of 12° to 23° from the vertical, the remaining two edge faces being parallel and substantially vertical, and having a plurality of parallel spaced channels in its bottom face, said block being characterized by a density of 85 to 155 lb. per cu ft., a compressive strength of at least 2500 psi, a flexure tensile strength of at least 300 psi, and a capability of undergoing at least 100 freeze-thaw cycles without cracking.
Claim 2
Dependent Claim
94 words
A roof ballast block having generally rectangular top and bottom faces, and two parallel edge faces bevelled at substantially identical angles of 12° to 23° from the vertical, the remaining two edge faces being parallel and substantially vertical, and having a plurality of parallel spaced channels in its bottom face, said block being characterized by a density of 85 to 155 lb. per cu ft., a compressive strength of at least 2500 psi, a flexure tensile strength of at least 300 psi, and a capability of undergoing at least 100 freeze-thaw cycles without cracking.
Claim 3
Dependent Claim
30 words
A ballast block as claimed in claim 1 in which said block has square top and bottom faces and in which said channels are parallel to said bevelled edge faces.
Claim 4
Dependent Claim
23 words
A ballast block as claimed in claim 1 having at least one additional channel in its bottom face transverse to said parallel channels.
Claim 5
Dependent Claim
44 words
A ballast block as claimed in claim 2 having at least one additional channel in its bottom face adjacent and parallel to one of said vertical edge faces, said block having a weight of 10 to 17 pounds per square foot of upper face.
References Cited (Backward Citations)
CA712301A
Cited
US1558129A
Cited
US2192458A
Cited
US2671441A
Cited
CH378510A
Cited
DE1268350B
Cited
US3387420A
Cited
US3892899A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-08-19 | 1989-02-18 | 1989-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-19 | 1993-02-18 | 1993-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-19 | 1997-02-18 | 1997-08-20 | $7700.00 | Window Closed / Lapsed |