US3675960A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self leveling spreader frame
Assignee: DELTA RESOURCES INCORPORATED A CORP OF WA
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Filing: 1970-04-01
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Granted: 1972-07-11
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Expires: 1990-04-01
Abstract
Abstract A sling assembly of four cables which are mounted in rectangular array about four pivot sheaves supports a spreader frame for use in fastening to containers or other loads to be hoisted. A set of two of the cables at one longitudinal end of the spreader frame are secured to a piston rod of a first hydraulic cylinder. The set of two remaining cables at the other longitudinal end of the spreader frame are secured to the piston rod of a second hydraulic cylinder. A hydraulic control circuit connects the cylinders with a source of pressurized fluid and interconnects the rod side and rear side of each respective cylinder. The spreader frame is leveled by opening a valve to release fluid from the rear side of the cylinder which has its piston rod secured to the cables supporting the high side of the spreader frame so that the weight of the container will retract the piston rod allowing the container to be leveled.
Inventors
- 👤 Edward J Mangold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 04:23
CPC Classifications
B; B66; B66C; B66C1/00; B66C1/10; B66C1/101
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
130 words
Apparatus for handling loads from a single point of suspension including a spreader frame having means for securing the spreader frame to the cargo and at least four cables for suspending said spreader frame from said single point, the improvements comprising leveling means secured to the spreader frame for adjusting the length of selected ones of said cables for positioning the load in a predetermined disposition, said leveling means being powered by the weight of the cargo suspended from the spreader frame and including at least two hydraulic cylinders and piston rods with said cylinders fixEd to the spreader frame, said piston rods being fixed to opposite longitudinally spaced pairs of said cables whereby extension and retraction of said piston rods varies the effective lengths of said pairs of cables.
Claim 2
Dependent Claim
130 words
Apparatus for handling loads from a single point of suspension including a spreader frame having means for securing the spreader frame to the cargo and at least four cables for suspending said spreader frame from said single point, the improvements comprising leveling means secured to the spreader frame for adjusting the length of selected ones of said cables for positioning the load in a predetermined disposition, said leveling means being powered by the weight of the cargo suspended from the spreader frame and including at least two hydraulic cylinders and piston rods with said cylinders fixEd to the spreader frame, said piston rods being fixed to opposite longitudinally spaced pairs of said cables whereby extension and retraction of said piston rods varies the effective lengths of said pairs of cables.
Claim 3
Dependent Claim
53 words
The apparatus defined by claim 1, wherein said four cables are entrained around sheaves secured adjacent four corners equidistantly spaced from the center of the spreader frame and wherein hydraulic control means are provided for selectively positioning said piston rods under the force of the weight of the cargo acting through said cables.
Claim 4
Dependent Claim
30 words
The apparatus defined by claim 2, wherein said hydraulic control means includes a regenerative fluid circuit coupled to said cylinders for recirculating the fluid to opposite ends of the cylinders.
Claim 5
Dependent Claim
68 words
The apparatus defined by claim 1, wherein said leveling means includes an hydraulic circuit having valve means operable to release fluid from the ends of said hydraulic cylinders pressurized by the weight of the cargo acting through the cables so as to move said piston rods and lengthen the effective length of the cables attached thereto to lower an end of the cargo to establish a horizontal disposition.
Claim 6
Dependent Claim
63 words
The apparatus defined by claim 4, including means interconnecting the opposite ends of said cylinders together so that fluid from one end of the cylinders may be moved to the opposite end, and further including releveling valve means for directing fluid under pressure to the ends of the cylinders opposite the piston rods to extend the piston rods when the load is removed.
References Cited (Backward Citations)
US3164406A
Cited
US3191983A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |