Automatic submarine trencher

Claim 2

In a trenching system for cutting a trench in the bed of a body of water and including: a frame, ground-engaging means coupled to said frame and adapted to move on said bed, at least one axially extending support arm, movable coupling means coupling said arm to said frame for selectively moving said support arm relative to said frame, and at least one rotatable cutter means extending downwardly from said support arm, the improvement comprising: hydraulic power means including a prime mover, a hydraulic pump, at least one hydraulic motor, a hydraulic circuit operatively coupling said pump to said motor to energize said motor with hydraulic fluid, means coupling the output shaft of said motor to said cutter means to rotate said cutter means when said motor is energized, and control means responsive to the pressure in the hydraulic circuit for automatically adjusting the power output of said motor.

Claim 3

The system of claim 1 wherein said motor is a piston-type motor having a speed control element, said control means is coupled to said speed control element to automatically vary the speed of said shaft in accordance with the variation in the amplitude of said pressure, and a floating marine vessel housing at least said prime mover and said hydraulic pump, said pump being coupled to said frame by a flexible umbilical cable.

Claim 4

The system of claim 4 wherein said ground-engaging means include: a pair of self-propelled tracks, and at least one hydraulic motor coupled to each track for moving said tracks, independently or simultaneously, on said bed toward or away from the direction of the trench being cut.

Claim 5

The system of claim 3 wherein said frame moves over a pipeline and further including: roller means rotatably supported on said frame and adapted to rollingly engage said pipeline at horizontally spaced locations for guiding said frame on said pipeline.

Claim 6

The system of claim 4 and further including: sensor means coupled to said roller means for monitoring the position of said frame relative to said pipeline, and monitoring means adapted to be positioned on said vessel and connected to said sensor means, said monitoring means being responsive to the signals produced by said sensor means for providing an indication of the position of said frame relative to said pipeline.

Claim 7

The system of claim 5 wherein said ground-engaging means include self-propelled track means remotely operated from said vessel in dependence on said monitored signals received from said sensor means.

Claim 8

The system of claim 6 wherein said cutter means extend downwardly at a predetermined depth below said ground-engaging means whereby forward motion of said frame causes said cutter means to cut a trench in said bed.

Claim 9

The system of claim 7 and further including: at least another axially extending support arm, movable coupling means coupling said arm to said frame for selectively moving said support arm relative to said frame, means movably interconnecting said arms for selective movement of said arms away from and toward each other, and at least another rotatable cUtter means extending downwardly from said another support arm.

Claim 10

The system of claim 8 wherein said frame extends rearwardly of said cutting means and is adapted for motion along said pipeline, and pivot means carried on said frame for imparting pivotal motion to said arms about a generally horizontal axis.

Claim 11

The system of claim 1 wherein said ground-engaging means is a skid adapted for sliding movement on the surface of said bed.

Claim 12

The system of claim 1 wherein said cutter means comprises a tubular member having outwardly extending, generally C-shaped blades thereon.

Claim 13

The system of claim 13 wherein said blades are in the form of scoops.

Claim 14

The system of claim 4 wherein said roller means are movably supported on said frame, and means for selectively positioning said roller means on said frame relative to said pipeline.

Claim 15

The system of claim 11 wherein said cutter means are detachably secured to their respective arms.

Claim 16

The system of claim 14 wherein said tubular member is hollow and further including: high-pressure water means connected to said tubular member to facilitate the trenching operation.

Claim 17

A trenching system for cutting a trench in the bed of a body of water including: a frame for moving over a pipeline, roller means rotatably supported on said frame and adapted to rollingly engage said pipeline at horizontally spaced locations for guiding said frame on said pipeline; ground-engaging means coupled to said frame and adapted to move on said bed; at least one axially extending support arm, movable coupling means coupling said arm to said frame for selectively moving said support arm relative to said frame; at least one rotatable cutter means extending downwardly from said support arm; said ground-engaging means including: a pair of self-propelled tracks, at least one hydraulic motor coupled to said tracks for moving said tracks on said bed toward or away from the direction of the trench being cut, a floating marine vessel coupled to said frame by a flexible umbilical cable, said vessel housing at least a prime mover and a hydraulic pump for energizing said hydraulic motor; sensor means coupled to said roller means for monitoring the position of said frame relative to said pipeline, monitoring means adapted to be positioned on said vessel and connected to said sensor means, said monitoring means being responsive to the signals produced by said sensor means for providing an indication of the position of said frame relative to said pipeline; and said track means being remotely operated from said vessel in dependence on said monitored signals received from said sensor means.

Claim 18

A trenching system for cutting a trench in the bed of a body of water including: a frame for moving over a pipeline, roller means rotatably supported on said frame and adapted to rollingly engage said pipeline at horizontally spaced locations for guiding said frame on said pipeline; ground-engaging means coupled to said frame and adapted to move on said bed; at least one axially extending support arm, movable coupling means coupling said arm to said frame for selectively moving said support arm relative to said frame; at least one rotatable cutter means extending downwardly from said support arm; said ground-engaging means including: a pair of self-propelled tracks, at least one hydraulic motor coupled to said tracks for moving said tracks on said bed toward or away from the direction of the trench being cut, a floating marine vessel coupled to said frame by a flexible umbilical cable, said vessel housing at least a prime mover and a hydraulic pump for energizing said hydraulic motor; sensor means coupled to said roller means for monitoring the position of said frame relative to said pipeline, monitoring means adapted to be positioned on said vessel and connected to said sensor means, said monitoring means being responsive to the signals produced by said sensor means for providing an indication of the position of said frame relative to said pipeline; and said track means being remotely operated from said vessel in dependence on said monitored signals received from said sensor means.

Claim 19

The system of claim 16 and further including: at least another axially extending support arm, movable coupling means coupling said another arm to said frame for selectively moving said another arm relative to said frame, means movably interconnecting said arms for selective movement of said arms away from and toward each other, and at least another rotatable cutter means extending downwardly from said another arm.

Claim 20

The system of claim 17 wherein each cutter means comprises a tubular member from the outer periphery of which outwardly extend generally C-shaped blades.

Claim 21

The system of claim 17 wherein said roller means are movably supported on said frame, and movable means coupled to said frame for selectively positioning said roller means on said frame relative to said pipeline.

Claim 22

The system of claim 19 wherein each of said cutter means is detachably secured to its corresponding arm.

Claim 23

The system of claim 20 wherein said tracks are detachably coupled to said frame.