US3986368A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Load equalizing and shock absorber system for off-shore drilling rigs
Assignee: LEVINGSTON SHIPBUILDING Co
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Filing: 1975-05-27
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Granted: 1976-10-19
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Expires: 1995-05-27
Abstract
Abstract A load equalizing system for a jack-up leg on a mobile off-shore drilling platform barge, wherein the leg has a plurality of rigidly interconnected generally parallel chords. Each of the chords is connected to the barge by a rack and pinion type jack assembly arranged for raising and lowering the leg relative to the platform and wherein lateral deflection of the leg by wave action or the like causes the chords to move vertically unequally relative to the barge. The improvement comprises a pair of hydraulic cylinder assemblies mounted between each of the jack assemblies and the barge, with the working axes thereof generally parallel with the longitudinal axis of the leg. Each cylinder assembly has a cylinder piston mounted therein and a piston rod connected to the piston and extending longitudinally therefrom. Each of the hydraulic cylinder assemblies has one end connected to the barge and the other end arranged for vertical bearing against the top of one of the jack assemblies. Conduit means are provided for interconnecting the fluid containing ends of the cylinders for permitting hydraulic fluid to be transmitted therebetween. Means are also provided for charging hydraulic cylinders with at least sufficient hydraulic fluid to maintain the piston rods at about mid-stroke, whereby unequal vertical loads on the chords are reduced by equalization of hydraulic pressure in the cylinders through the conduit means. In the shock absorbing mode, the system includes a plurality of accumulators, each of which is arranged for containing a quantity of gas. Second conduit means are arranged for interconnecting the cylinders with the accumulators. Means are also provided for pressurizing the accumulators with gas whereby shock force exerted on the leg, as would be caused by heaving of the barge during raising and lowering of the leg, are absorbed by displacement of hydraulic fluid from the cylinder to the accumulators and compression of the gas therein.
Inventors
- 👤 Clarence W. Levingston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:27
CPC Classifications
E; E02; E02B; E02B17/00; E02B17/02; E02B17/021; E02B17/024; E02B17/04; E02B17/08; E02B17/0818; E02B2017/0056; E02B2017/006; E02B2017/0073; E02B2017/0082
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
258 words
A load equalizing system for a jack-up leg on a barge type drilling platform wherein the leg is supported by the platform during movement of the platform to location and said leg engages the sea bottom and supports said platform when on location and wherein said leg has at least two rigidly interconnected generally parallel chords and each of said chords is connected to said platform by a jack assembly arranged for raising and lowering said leg relative to said platform and wherein lateral deflection of said leg tends to cause said chords to move vertically unequally relative to said platform, the improvement comprising: at least one hydraulic cylinder assembly mounted between each of said jack assemblies and said platform, with the working axes thereof generally parallel with the longitudinal axis of said leg, and each of said cylinder assemblies having a cylinder, a piston mounted therein, and a piston rod connected to said piston and extending longitudinally therefrom; each of said hydraulic cylinder assemblies having one end connected to said platform and the other end arranged for vertical bearing against a portion of one of said jack assemblies; conduit means interconnecting the fluid containing ends of said cylinders for permitting hydraulic fluid pressure to be transmitted therebetween; and a quantity of hydraulic fluid contained in each of said cylinders to normally maintain said piston rods at least about mid-stroke, whereby unequal vertical loads on said chords caused by lateral deflection of said leg are reduced by equalization of hydraulic pressure in said cylinders through said conduit means.
Claim 2
Dependent Claim
258 words
A load equalizing system for a jack-up leg on a barge type drilling platform wherein the leg is supported by the platform during movement of the platform to location and said leg engages the sea bottom and supports said platform when on location and wherein said leg has at least two rigidly interconnected generally parallel chords and each of said chords is connected to said platform by a jack assembly arranged for raising and lowering said leg relative to said platform and wherein lateral deflection of said leg tends to cause said chords to move vertically unequally relative to said platform, the improvement comprising: at least one hydraulic cylinder assembly mounted between each of said jack assemblies and said platform, with the working axes thereof generally parallel with the longitudinal axis of said leg, and each of said cylinder assemblies having a cylinder, a piston mounted therein, and a piston rod connected to said piston and extending longitudinally therefrom; each of said hydraulic cylinder assemblies having one end connected to said platform and the other end arranged for vertical bearing against a portion of one of said jack assemblies; conduit means interconnecting the fluid containing ends of said cylinders for permitting hydraulic fluid pressure to be transmitted therebetween; and a quantity of hydraulic fluid contained in each of said cylinders to normally maintain said piston rods at least about mid-stroke, whereby unequal vertical loads on said chords caused by lateral deflection of said leg are reduced by equalization of hydraulic pressure in said cylinders through said conduit means.
Claim 3
Dependent Claim
68 words
The invention as claimed in claim 1 including: a plurality of compressible fluid reservoirs each of which has a conduit interconnecting with the fluid containing end of one of said cylinders; and means for pressurizing said reservoirs accumulators with a compressible fluid whereby shock forces are absorbed by compression of said fluid when said pistons retract in response to shock forces exerted between said leg and said platform.
Claim 4
Dependent Claim
26 words
The invention as claimed in claim 1 wherein said system includes: a pair of said hydraulic cylinder assemblies mounted between said jack assembly and said platform.
Claim 5
Dependent Claim
37 words
The invention as claimed in claim 1 wherein: said platform includes an upper support structure rigidly attached thereto; and said hydraulic cylinder assembly is mounted between the top of said jack assembly and said upper support structure.
Claim 6
Dependent Claim
49 words
The invention as claimed in claim 1 wherein: each of said chords has mounted thereon a gear rack; and said jack assembly includes at least one pinion gear arranged to engage said gear rack, whereby rotation of said gear causes vertical movement of said chord relative to said platform.
Claim 7
Dependent Claim
44 words
The invention as claimed in claim 2 wherein: said reservoirs are in the form of hydraulic accumulators each having valve means at the lower end thereof for bleeding hydraulic fluid therefrom and another valve means at the upper end thereof for bleeding gas therefrom.
Claim 8
Dependent Claim
19 words
The invention as claimed in claim 6 including: pump means for charging said cylinders and accumulators with hydraulic fluid.
Claim 9
Dependent Claim
25 words
The invention as claimed in claim 6 including: a source of pressurized gas connected to said accumulator for charging said accumulator with gas as desired.
Claim 10
Dependent Claim
226 words
A load equalizing system for a jack-up leg on a mobile off-shore drilling barge wherein said leg has a plurality of rigidly interconnected generally parallel chords and with each of said chords connected to said barge by a rack and pinion type jack assembly arranged for raising and lowering said leg relative to said platform and wherein lateral deflection of said leg by wave action or the like causes said chords to move vertically unequally relative to said barge, the improvement comprising: a pair of hydraulic cylinder assemblies mounted between each of said jack assemblies and said barge, with the working axes thereof generally parallel with the longitudinal axis of said leg, and each cylinder assembly having a cylinder, a piston mounted therein, and a piston rod connected to said piston and extending longitudinally therefrom; each of said hydraulic cylinder assemblies having one end connected to said barge and the other end arranged for vertical bearing against the top of one of said jack assemblies; conduit means for interconnecting the fluid containing ends of said cylinders for permitting hydraulic fluid to be transmitted therebetween; and means for charging said hydraulic cylinders with at least sufficient hydraulic fluid to maintain said piston rods at about mid-stroke, whereby unequal vertical loads on said chords are reduced by equalization of hydraulic pressure in said cylinders through said conduit means.
Claim 11
Dependent Claim
226 words
A load equalizing system for a jack-up leg on a mobile off-shore drilling barge wherein said leg has a plurality of rigidly interconnected generally parallel chords and with each of said chords connected to said barge by a rack and pinion type jack assembly arranged for raising and lowering said leg relative to said platform and wherein lateral deflection of said leg by wave action or the like causes said chords to move vertically unequally relative to said barge, the improvement comprising: a pair of hydraulic cylinder assemblies mounted between each of said jack assemblies and said barge, with the working axes thereof generally parallel with the longitudinal axis of said leg, and each cylinder assembly having a cylinder, a piston mounted therein, and a piston rod connected to said piston and extending longitudinally therefrom; each of said hydraulic cylinder assemblies having one end connected to said barge and the other end arranged for vertical bearing against the top of one of said jack assemblies; conduit means for interconnecting the fluid containing ends of said cylinders for permitting hydraulic fluid to be transmitted therebetween; and means for charging said hydraulic cylinders with at least sufficient hydraulic fluid to maintain said piston rods at about mid-stroke, whereby unequal vertical loads on said chords are reduced by equalization of hydraulic pressure in said cylinders through said conduit means.
Claim 12
Dependent Claim
74 words
The invention as claimed in claim 9 including a plurality of accumulators, each of which is arranged for containing a quantity of compressible fluid; second conduit means interconnecting each one of said cylinders and one of said accumulators; and means for pressurizing said accumulators with gas, whereby shock force exerted on said leg is absorbed by displacement of hydraulic fluid from said cylinder to said accumulator and compression of said gas in said accumulators.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-10-19 | 1980-04-19 | 1980-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-19 | 1984-04-19 | 1984-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-19 | 1988-04-19 | 1988-10-19 | $7700.00 | Window Closed / Lapsed |