Underwater pipeline trenching apparatus

Claim 2

An underwater pipeline trenching apparatus comprising, a carriage unit adapted for support upon a pipeline disposed on the floor of a body of water, said carriage including an inner frame section and a pair of outer frame sections, a plurality of support rollers on said inner frame section engageable with the periphery of the pipeline when said carriage unit is in its normal working position, said outer frame sections pivotally attached to said inner Frame section for movement between an open position and a clamping position with respect to said pipeline, guide means on said outer frame sections engageable with said pipeline when said outer frame sections are in the clamping position, a rotary cutter drum attached to each outer frame section, a propulsion section disposed adjacent one end of said carriage unit, reciprocating drive means connected to said propulsion section for alternately moving said propulsion section towards and away from said carriage unit, guide members attached to said carriage unit and longitudinally extending from one end thereof, slide means on said propulsion section engaging said guide members, and clamping means on said propulsion section selectively engageable with the pipeline to lock said propulsion section thereto whereby, said drive means may be actuated to propel said carriage unit along said pipeline.

Claim 3

An underwater apparatus according to claim 1 wherein, said cutter drums are attached to the forward end of said outer frame sections and said propulsion section is joined to the rear of said carriage unit.

Claim 4

An underwater apparatus according to claim 1 including, a fluid-actuated cylinder connected between each said outer frame section and said inner frame section for selectively displacing said outer frame sections between the open and clamping positions.

Claim 5

An underwater apparatus according to claim 1 wherein, said inner frame section is normally disposed above the top of said pipeline and said support rollers engage the upper portion of the pipeline periphery, and said outer frame section guide means is disposed on the lower portion of said outer frame sections and engages the lower portion of the pipeline periphery when in the clamping position.

Claim 6

An underwater apparatus according to claim 1 wherein, each said cutter drum includes a central tube having an internal passageway extending from its bottom opening to its top opening, and a plurality of cutter bars adjacent the exterior of said tube and connected thereto by means of outwardly extending brackets.

Claim 7

An underwater apparatus according to claim 5 including, pairs of diametrically opposed cutter bars projecting from said tube, and successive pairs of said bars are angularly offset with respect to one another.

Claim 8

An underwater apparatus according to claim 6 including, pairs of said cutter bars successively angularly offset from one another from the uppermost to the lowermost of said pairs.

Claim 9

An underwater apparatus according to claim 6 including, a pair of said cutter bars extending substantially below said bottom opening.

Claim 10

An underwater apparatus according to claim 1 including, water jet nozzles supported upon said carriage and directed towards each said cutter drum.

Claim 11

An underwater pipeline trenching apparatus comprising, a carriage unit adapted for support upon a pipeline disposed on the floor of a body of water, said carriage including an inner frame section and a pair of outer frame sections, a plurality of support rollers on said inner frame section engageable with the periphery of the pipeline when said carriage unit is in its normal working position, said outer frame sections pivotally attached to said inner frame section for movement between an open position and clamping position with respect to said pipeline, guide means on said outer frame sections engageable with said pipeline when said outer frame sections are in the clamping position, a rotary cutter drum attached to each outer frame section, a propulsion section disposed adjacent one end of said carriage unit, reciprocating drive means connected to said propulsion section for alternately moving said propulsion section towards and away from said carriage unit, and clamping means on said propulsion section selectively engageable with the pipeline to lock said propulsion section thereto, said propulsion section clamping means including a pair of arcuate shoes pivotally mounted on said propulsion section, a fluid-actuated cylinder conNected to each said shoe for displacing same between its locking and released positions whereby, said drive means may be actuated to propel said carriage unit along said pipeline.

Claim 12

An underwater pipeline trenching apparatus comprising, a carriage unit adapted for support upon a pipeline disposed on the floor of a body of water, said carriage including an inner frame section and a pair of outer frame sections, a plurality of support rollers on said inner frame section engageable with the periphery of the pipeline when said carriage unit is in its normal working position, said outer frame sections pivotally attached to said inner frame section for movement between an open position and clamping position with respect to said pipeline, guide means on said outer frame sections engageable with said pipeline when said outer frame sections are in the clamping position, a rotary cutter drum attached to each outer frame section, a propulsion section disposed adjacent one end of said carriage unit, reciprocating drive means connected to said propulsion section for alternately moving said propulsion section towards and away from said carriage unit, and clamping means on said propulsion section selectively engageable with the pipeline to lock said propulsion section thereto, said propulsion section clamping means including a pair of arcuate shoes pivotally mounted on said propulsion section, a fluid-actuated cylinder conNected to each said shoe for displacing same between its locking and released positions whereby, said drive means may be actuated to propel said carriage unit along said pipeline.

Claim 13

An underwater pipeline trenching apparatus comprising, a carriage unit adapted for support upon a pipeline disposed on the floor of a body of water, said carriage including an inner frame section and a pair of outer frame sections, a plurality of support rollers on said inner frame section engageable with the periphery of the pipeline when said carriage unit is in its normal working position, said outer frame sections pivotally attached to said inner frame section for movement between an open position and a clamping position with respect to said pipeline, guide means on said outer frame sections engageable with said pipeline when said outer frame sections are in the clamping position, a rotary cutter drum attached to each outer frame section, each said cutter drum includes a central tube having an internal passageway extending from its bottom opening to its top opening, and a plurality of cutter bars adjacent the exterior of said tube and connected thereto by means of outwardly extending brackets, a suction dredge pump mounted adjacent the upper portion of said tube and communicating with said top opening, propulsion section disposed adjacent one end of said carriage unit, reciprocating drive means connected to said propulsion section for alternately moving said propulsion section towards and away from said carriage unit, and clamping means on said propulsion section selectively engageable with the pipeline to lock said propulsion section thereto whereby, said drive means may be actuated to propel said carriage unit along said pipeline.

Claim 14

An underwater pipeline trenching apparatus comprising, a carriage unit adapted for support upon a pipeline disposed on the floor of a body of water, said carriage including an inner frame section and a pair of outer frame sections, a plurality of support rollers on said inner frame section engageable with the periphery of the pipeline when said carriage unit is in its normal working position, said outer frame sections pivotally attached to said inner frame section for movement between an open position and a clamping position with respect to said pipeline, guide means on said outer frame sections engageable with said pipeline when said outer frame sections are in the clamping position, a rotary cutter drum attached to each outer frame section, each said cutter drum includes a central tube having an internal passageway extending from its bottom opening to its top opening, and a plurality of cutter bars adjacent the exterior of said tube and connected thereto by means of outwardly extending brackets, a suction dredge pump mounted adjacent the upper portion of said tube and communicating with said top opening, propulsion section disposed adjacent one end of said carriage unit, reciprocating drive means connected to said propulsion section for alternately moving said propulsion section towards and away from said carriage unit, and clamping means on said propulsion section selectively engageable with the pipeline to lock said propulsion section thereto whereby, said drive means may be actuated to propel said carriage unit along said pipeline.