UNDERWATER PIPELINE AND CABLE TRENCHING APPARATUS

• US 3,732,700 A
• Filed: 08/19/1971
• Issued: 05/15/1973
• Est. Priority Date: 08/19/1971
• Status: Expired due to Term

• Current Assignee: Robert P. Lynch
• Original Assignee: Robert P. Lynch
• Inventors: Lynch, Robert P.
• Primary Examiner(s): Shapiro, Jacob
• Application Number:
  US05/173,161
• Time in Patent Office: 635 Days
• Field of Search: 61/72.4,72.1,72.3,63,64,65,61
• US Class Current: 405/163
• CPC Class Codes: E02F 5/105 self-propulsed units moving on the underwater bottom
• CPC Class Codes: E02F 5/109 using rotating digging elements rotating digging elements per se E02F3/18

Abstract

An underwater trenching apparatus includes a bottom-riding frame assembly provided with a rotary cutter member carried thereby. A plurality of vertical and horizontal rollers support and guide a pipeline above and adjacent to the cutting elements of the cutter member during advancement to the apparatus. Movable means are included to permit displacement of at least one of said rollers to allow lateral insertion or removal of the pipeline from within the confines of the plurality of rollers after the frame assembly is disposed upon the ocean floor in a straddling manner over the pipeline.

Claims

1. An underwater pipeline and cable trenching apparatus comprising, a frame assembly including a pair of spaced apart side frames each having support means for slidably engaging the ocean floor, a substantially vertically disposed cutter assembly mounted upon said frame assembly between said side frames, said cutter assembly provided with a central torque tube journalled for rotary movement and extending downwardly below said frame assembly, a plurality of cutter bars mounted upon said tube in a standoff manner, motor means on said frame assembly for driving said cutter assembly, pipeline guiding and supporting means disposed between said side frames and adjacent said cutter assembly, said pipeline guiding and supporting means including a fixed horizontally disposed bottom support member having an upper surface in a plane no lower than the bottom of said side frame support means, a fixed vertically disposed inner support member adjacent said bottom support member, a vertically disposed outer support member adjacent said bottom support member and laterally spaced from said inner support member, said outer supPort member mounted for adjustable movement towards and away from said inner support member, a water jet pipe carried by said frame assembly and disposed adjacent said cutter assembly and advancing means connected to said frame assembly for propelling the apparatus when a pipeline is disposed within the confines of said bottom, inner and outer support members and said cutter tube is rotating and said jet pipe is operating.

2. An underwater apparatus according to claim 1 wherein, said side frame support means comprises a longitudinally extending pad.

3. An underwater apparatus according to claim 1 including, pairs of said cutter bars mounted upon said tube in diametrically opposed relationship, and successive pairs of said bars are angularly offset with respect to one another.

4. An underwater apparatus according to claim 1 including, laterally extending brackets connecting said cutter bars to said torque tube and said cutter bars describe an inverted frusto-conical configuration.

5. An underwater apparatus according to clam 1 wherein, said cutter torque tube is hollow and includes a bottom opening and a top-mounted suction dredge pump.

6. An underwater apparatus according to claim 1 wherein, the leading edges of said cutter bars are beveled.

7. An underwater apparatus according to claim 1 wherein, said bottom, inner and outer support members comprise rollers.

8. An underwater apparatus according to claim 1 wherein, said outer support member comprises a roller pivotally attached at its upper end to said frame assembly.

9. An underwater apparatus according to claim 1 including, an air lift pipe carried by said frame assembly and disposed adjacent said cutter assembly and water jet pipe.

10. An underwater apparatus according to claim 1 wherein, said advancing means comprises a tow cable attached to the forward portion of said frame assembly.

11. An underwater apparatus according to claim 1 wherein, said advancing means comprises a traction wheel assembly adjustably mounted adjacent the forward portion of said frame assembly.

12. An underwater apparatus according to claim 11 wherein, said traction wheel assembly includes, a pair of frame arms pivotally attached to said frame assembly, a transverse axle supported between the free ends of said frame arms, spaced apart lateral support means radially extending from said axle, a plurality of radially projecting drive plates mounted between said spaced apart support means, and motor means connected to said axle for rotating same to propell said apparatus as said drive plates dig into the ocean floor.

13. An underwater apparatus according to claim 12 including, fluid cylinder means connecting said traction wheel assembly to said frame assembly for pivotal adjustment therebetween.

14. An underwater apparatus according to claim 12 wherein, said axle includes a cable winch drum thereon.