Patent US4254887A successfully refreshed from Google Patents.
US4254887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Storage tank
Assignee: BP PLC
•
Filing: 1979-03-06
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Granted: 1981-03-10
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Expires: 1999-03-06
Abstract
Abstract Liquid storage tank containing a collapsible bag of flexible impervious sheet material supported by a collar within the tank which floats on the stored liquid and moves with the liquid thereby dividing the interior of the shell into an air and a liquid space. The bag has an external skirt of a similar flexible sheet material attached to the supporting collar which lies between the bag and adjacent tank side walls to reduce abrasion and catching of the bag and tank walls particularly during tank emptying and filling procedures.
Inventors
- 👤 Stephen E. Bold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:49
CPC Classifications
B; B65; B65D; B65D90/00; B65D90/22; B65D90/38
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
175 words
A liquid storage tank comprising a rigid shell having substantially vertical walls, a collapsible bag of impervious flexible sheet material positioned within the tank and dividing the interior or the rigid shell into an air space and a liquid space, peripherally disposed supporting means interiorly positioned around said vertical walls of the tank near the upper peripheral portion of the bag for engaging and supporting the bag inside the tank and for maintaining the bag in spaced relation from the vertical walls of the tank, and a skirt attached to the external wall of the bag near the upper peripheral portion of the bag at the jointure point of the supporting means and the bag and positioned external to the bag and the supporting means so that the said skirt is interposed between the bag and the supporting means and the adjacent vertical walls of the tank, said skirt extending to a position near the base of the tank so that said skirt prevents said bag from contacting said adjacent vertical walls of the tank.
Claim 2
Dependent Claim
175 words
A liquid storage tank comprising a rigid shell having substantially vertical walls, a collapsible bag of impervious flexible sheet material positioned within the tank and dividing the interior or the rigid shell into an air space and a liquid space, peripherally disposed supporting means interiorly positioned around said vertical walls of the tank near the upper peripheral portion of the bag for engaging and supporting the bag inside the tank and for maintaining the bag in spaced relation from the vertical walls of the tank, and a skirt attached to the external wall of the bag near the upper peripheral portion of the bag at the jointure point of the supporting means and the bag and positioned external to the bag and the supporting means so that the said skirt is interposed between the bag and the supporting means and the adjacent vertical walls of the tank, said skirt extending to a position near the base of the tank so that said skirt prevents said bag from contacting said adjacent vertical walls of the tank.
Claim 3
Dependent Claim
25 words
A tank according to claim 1 in which the supporting means for supporting the bag in the tank comprises peripheral collar attached to the bag.
Claim 4
Dependent Claim
21 words
A tank according to claim 2 in which the skirt passes between the collar and adjacent side wall of the tank.
Claim 5
Dependent Claim
13 words
A tank according to claim 2 in which the peripheral collar is inflatable.
Claim 6
Dependent Claim
32 words
A tank according to claim 4 in which the inflatable collar is inflated into a peripheral recess in the side walls of the tank to assist in holding the collar in place.
Claim 7
Dependent Claim
31 words
A tank according to claim 4 in which the inflatable collar is supported by flanges disposed in the side walls of the tank to assist in holding the collar in place.
Claim 8
Dependent Claim
18 words
A tank according to claim 4 in which the inflatable collar is attached to an external pressurising source.
Claim 9
Dependent Claim
20 words
A tank according to claim 1 in which the skirt is formed from the same material as the collapsible bag.
Claim 10
Dependent Claim
22 words
A tank according to claim 1 in which the skirt is formed from a polyurethane, polyvinyl floride, polyvinylidene chloride or a polyester.
Claim 11
Dependent Claim
17 words
A tank according to claim 1 in which the collapsible bag and skirt contain an anti-static compound.
Claim 12
Dependent Claim
12 words
A tank according to claim 1 in which the skirt is weighted.
Claim 13
Dependent Claim
16 words
A tank according to claim 1 in which the upper part of the skirt is perforated.
Claim 14
Dependent Claim
19 words
A tank according to claim 1 in which the skirt has a thickness of from 12 to 50 microns.
Claim 15
Dependent Claim
49 words
A tank according to claim 1 in which the collapsible bag in its fully extended form comprises a truncated cone which tapers away from the open end of the bag and having sufficient rigidity to maintain the walls of the bag apart from the side walls of the tank.
Claim 16
Dependent Claim
22 words
A tank according to claim 14 in which the degree of taper of the cone is 1° to 10° from the vertical.
Claim 17
Dependent Claim
35 words
A tank according to claim 1 in which the collapsible bag in its fully extended form comprises a cylinder having circumferential bracing rings, the diameter of the rings being less than the storage tank diameter.
References Cited (Backward Citations)
GB1059954A
Cited
US3617034A
Cited
US3752355A
Cited
US3779419A
Cited
US3931907A
Cited
US4079856A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-09 | 1984-09-08 | 1985-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-09 | 1988-09-08 | 1989-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-09 | 1992-09-08 | 1993-03-10 | $7700.00 | Window Closed / Lapsed |