US3777376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Articulated ladder construction for cutterhead dredge
Assignee: Ellicott Machine Corp
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Filing: 1972-02-04
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Granted: 1973-12-11
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Expires: 1992-02-04
Abstract
Abstract An articulated ladder for a cutterhead dredge especially adapted for use in rough water and wherein the ladder, rather than being a unitary rigid member, is constructed in two parts connected together at adjacent ends by a link whereby the thrust due to wave action on the ladder part trunnioned to the dredge cannot be transmitted to the cutterhead and, by reaction of the latter against the bottom, back to the trunnions.
Inventors
- 👤 T Turner
- 👤 F Keefe
- 👤 C Little
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:21
CPC Classifications
E; E02; E02F; E02F9/00; E02F9/06; E02F9/067; E02F3/00; E02F3/04; E02F3/88; E02F3/90; E02F3/92; E02F3/9212; E02F3/9225; E02F3/9231; E02F5/00; E02F5/006
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
144 words
Dredging apparatus for use in heavy seas comprising a barge and an articulated ladder, said ladder comprising a first rigid upper ladder part having its inner end pivoted to said barge, a second rigid lower ladder part carrying adjacent its outer end a cutter-head, a downwardly extending rigid link having its upper end freely pivoted to the outer end of said first ladder part so that said link swingably depends from said outer end, said link having its lower end freely pivoted to the inner end of the second ladder part so that said second ladder part is angularly movable relative to the upper ladder part, and means for adjustably positioning said first ladder part at a selected angle relative to said barge so that the lower end of said link is positioned clear above the sea bottom during dredging operations in heavy seas.
Claim 2
Dependent Claim
144 words
Dredging apparatus for use in heavy seas comprising a barge and an articulated ladder, said ladder comprising a first rigid upper ladder part having its inner end pivoted to said barge, a second rigid lower ladder part carrying adjacent its outer end a cutter-head, a downwardly extending rigid link having its upper end freely pivoted to the outer end of said first ladder part so that said link swingably depends from said outer end, said link having its lower end freely pivoted to the inner end of the second ladder part so that said second ladder part is angularly movable relative to the upper ladder part, and means for adjustably positioning said first ladder part at a selected angle relative to said barge so that the lower end of said link is positioned clear above the sea bottom during dredging operations in heavy seas.
Claim 3
Dependent Claim
22 words
Apparatus of claim 1 including means carried by said second ladder part and operatively connected to said cutter-head for driving the same.
Claim 4
Dependent Claim
21 words
Apparatus of claim 2 wherein the means for driving the cutterhead comprises hydraulic motor means carried by said second ladder part.
Claim 5
Dependent Claim
48 words
Apparatus of claim 2 including a centrifugal pump carried by said second ladder part, a suction pipe extending from said cutterhead to the inlet of said pump and flexible conduit means connected to the outlet of said pump and connected to a second pump carried by said barge.
Claim 6
Dependent Claim
88 words
Apparatus of claim 4 wherein said flexible conduit means includes a pipe section carried by said link, a first swivel coupling connecting the outlet of said pump to one end of said pipe section, a pipe carried by said first ladder part and adapted to be connected at one end to said second centrifugal pump on said hull and a second swivel coupling connecting the opposite end of the pipe section carried by said link to an adjacent end of the pipe carried by said first ladder part.
Claim 7
Dependent Claim
78 words
Apparatus of claim 5 wherein said link is connected to said ladder parts by pairs of upper and lower laterally spaced bearing pins, fluid passages extending co-axially through the upper and lower bearing pins on the side of said link adjacent the ends of said pipe section, said ends being connected through said swivel couplings and the passages in said pins to the outlet of said pump and to the pipe carried by said first ladder part, respectively.
Claim 8
Dependent Claim
67 words
Apparatus of claim 1 including support means connected to said second ladder part for exerting a lifting force thereon, and means responsive to changes in load on the support means by the second ladder part as the dredge pitches in seas for varying the lifting force of the support means so that the force exerted by the cutterhead on the bottom is at all times substantially constant.
Claim 9
Dependent Claim
24 words
Apparatus of claim 7 including manually operable control means carried on the hull for selecting the degree of lift exerted by said support means.
Claim 10
Dependent Claim
88 words
Apparatus of claim 7 wherein the support means comprises a hydraulic piston and cylinder connected between first and second ladder parts, an hydraulic inlet connected to said cylinder so as to deliver hydraulic pressure fluid to said piston in opposition to the weight of said second ladder part, conduit means connecting said inlet to the hydraulic cavity of an accumulator carried by said barge, and second conduit means including a manually adjustable pressure regulating valve connecting the pneumatic cavity of said accumulator to a source of pneumatic pressure.
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) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |