Patent US4934715A successfully refreshed from Google Patents.
US4934715A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gasket for use with manhole covers
Assignee: Individual
•
Filing: 1989-01-09
•
Granted: 1990-06-19
•
Expires: 2009-01-09
Abstract
Abstract An improved gasket for use with manhole covers. The gasket is of the type which is fabricated from rubber and is held in a circular groove formed in the flat cover support surface of a cast iron frame of the type which holes a manhole cover. The manhole cover fits in the frame and rests on the gasket. The improved gasket has a vertical portion which is generally rectangular which fits into the circular groove. The gasket also has a horizontal portion which extends beyond the groove and onto the flat cover support surface of the frame.
Inventors
- 👤 Roy E. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:55
CPC Classifications
E; E02; E02D; E02D29/00; E02D29/12; E02D29/14; E02D29/149; F; F16; F16J; F16J15/00; F16J15/02; F16J15/021; F16J15/022; F16J15/024; F16L; F16L23/00; F16L23/16; F16L23/18; Y; Y10; Y10S; Y10S285/00; Y10S285/918
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
127 words
An improved gasket for use with manhole covers, said gasket being of the type which is fabricated from an elastomer and is held in a circular groove formed in a flat cover support surface of a cast iron frame, said circular groove having a rectangular cross section wherein the improvement comprises: a gasket having a vertical portion which is generally rectangular in shape, which vertical portion fits into the circular groove and said gasket further having a horizontal portion having a generally flat bottom which extends beyond the groove and onto the flat cover support surface of the frame and wherein the horizontal portion is curved so that it is thinner at its outer edge than it is at its point of connection with the vertical portion.
Claim 2
Dependent Claim
127 words
An improved gasket for use with manhole covers, said gasket being of the type which is fabricated from an elastomer and is held in a circular groove formed in a flat cover support surface of a cast iron frame, said circular groove having a rectangular cross section wherein the improvement comprises: a gasket having a vertical portion which is generally rectangular in shape, which vertical portion fits into the circular groove and said gasket further having a horizontal portion having a generally flat bottom which extends beyond the groove and onto the flat cover support surface of the frame and wherein the horizontal portion is curved so that it is thinner at its outer edge than it is at its point of connection with the vertical portion.
Claim 3
Dependent Claim
23 words
The improved gasket of claim 1 wherein the horizontal portion extends away from the vertical portion on both sides of the vertical portion.
Claim 4
Dependent Claim
33 words
The improved gasket of claim 2 wherein the horizontal portion has a curved upper surface whereby the outer edges of the horizontal portion are thinner than the inner portions of the horizontal portion.
Claim 5
Dependent Claim
129 words
An improved gasket for use with manhole covers, said gasket being of the type which is fabricated from an elastomer and is held in a circular groove formed in a flat cover support surface of a cast iron frame, said groove having a rectangular cross section wherein the improvement comprises: a gasket having a generally "T" shaped cross section with the vertical portion of the "T" being generally rectangular in shape which fits into the circular groove, and the horizontal portion of the "T" shaped cross section having a generally flat bottom which extends beyond the groove and onto the flat cover support surface of the frame, and the horizontal portion of the "T" shaped cross section having a curved top which is tapered at the outer edges thereof.
Claim 6
Dependent Claim
129 words
An improved gasket for use with manhole covers, said gasket being of the type which is fabricated from an elastomer and is held in a circular groove formed in a flat cover support surface of a cast iron frame, said groove having a rectangular cross section wherein the improvement comprises: a gasket having a generally "T" shaped cross section with the vertical portion of the "T" being generally rectangular in shape which fits into the circular groove, and the horizontal portion of the "T" shaped cross section having a generally flat bottom which extends beyond the groove and onto the flat cover support surface of the frame, and the horizontal portion of the "T" shaped cross section having a curved top which is tapered at the outer edges thereof.
Claim 7
Dependent Claim
25 words
The improved gasket of claim 4 further including a generally inverted "V" shaped groove formed in the bottom of the vertical portion of the gasket.
Claim 8
Dependent Claim
24 words
The improved gasket of claim 4 further including a plurality of grooves formed in the upper surface on the horizontal portion of the gasket.
References Cited (Backward Citations)
US2929531A
Cited
US3063439A
Cited
US3334774A
Cited
US4192520A
Cited
US4290616A
Cited
US4819953A
Cited
US4828274A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |