Claims Analysis
Total Claims: 73
Claim 1
Independent Claim
126 words
An underwater trenching apparatus for burying pipeline and the like comprising: a frame for positioning about the pipeline to be buried, said frame including frame members positioned on each side of said pipeline, roller means connected to at least one of said frame members for engagement with said pipeline, pivot means positioned on said frame for pivoting each said frame member about a substantially horizontal axis parallel to the pipeline transversely toward and away from roller engagement with said pipeline, means operative upon said frame for laterally moving said pivot means and said horizontal axis to shift said frame members transversely to the axis of the pipeline, and cutting means secured to said apparatus for cutting a trench in a formation whereby said pipeline is buried.
Claim 2
Dependent Claim
126 words
An underwater trenching apparatus for burying pipeline and the like comprising: a frame for positioning about the pipeline to be buried, said frame including frame members positioned on each side of said pipeline, roller means connected to at least one of said frame members for engagement with said pipeline, pivot means positioned on said frame for pivoting each said frame member about a substantially horizontal axis parallel to the pipeline transversely toward and away from roller engagement with said pipeline, means operative upon said frame for laterally moving said pivot means and said horizontal axis to shift said frame members transversely to the axis of the pipeline, and cutting means secured to said apparatus for cutting a trench in a formation whereby said pipeline is buried.
Claim 3
Dependent Claim
49 words
The underwater trenching apparatus of claim 1 including, said pivot means including power means connected to said frame member and extending transversely to said pipeline for selectively and independently moving the fore and aft portions of each said frame member toward and away from roller engagement with said pipeline.
Claim 4
Dependent Claim
36 words
The underwater trenching apparatus of claim 1 including, said pivot means including power means being connected separately to the fore portion and to the aft portion of said frame member and extending transversely to said pipeline.
Claim 5
Dependent Claim
61 words
The underwater trenching apparatus of claim 1 including, said pivot means including power means connected to the fore and aft portions of each said frame member and extending transversely to said pipeline for bending the frame member upon selective moving of one portion of said frame member relative to said pipeline without moving the remaining portions of the same frame member.
Claim 6
Dependent Claim
37 words
The underwater trenching apparatus of claim 1 including, said pivot means including a plurality of power rams for selective movement of the fore and aft portions of each said frame member toward and away from roller engagement.
Claim 7
Dependent Claim
51 words
The underwater trenching apparatus of claim 5 including said power rams being connected separately to the fore and aft portion of each said frame member and extending transversely to said pipeline for selectively bending said frame member relative to said pipeline without moving the remaining portion of the same frame member.
Claim 8
Dependent Claim
41 words
The underwater trenching apparatus of claim 1 including, said roller means including at least one drive roller in contact with said pipeline in each of a fore portion of a frame member and in an aft portion of a frame member.
Claim 9
Dependent Claim
61 words
The underwater trenching apparatus of claim 7 including, said pivot means including power means connected to the fore and aft portions of each said frame member and extending transversely to said pipeline for bending the frame member upon selective moving of one portion of said frame member relative to said pipeline without moving the remaining portion of the same frame member.
Claim 10
Dependent Claim
51 words
The underwater trenching apparatus of claim 8 including, said power means being connected separately to the fore and aft portion of each said frame member and extending transversely to said pipeline for selectively bending said frame member relative to said pipeline without moving the remaining portion of the same frame member.
Claim 11
Dependent Claim
61 words
The underwater trenching apparatus of claim 7 including, said pivot means including power means connected to the fore and aft portions of each said frame member and extending transversely to said pipeline for bending the frame member upon selective moving of one portion of said frame member relative to said pipeline without moving the remaining portions of the same frame members.
Claim 12
Dependent Claim
38 words
The underwater trenching apparatus of claim 7 including, drive means for each said drive roller, control means to alternately drive a selected roller in contact with said pipeline with sufficient force to move said apparatus along said pipeline.
Claim 13
Dependent Claim
72 words
The underwater trenching apparatus of claim 2 including, said roller means including at least one drive roller in drive contact with said pipeline in each of a fore portion of a frame member and in an aft portion of a frame member, drive means for each said drive roller, control means to drive said roller remaining in driving engagement with said pipeline with sufficient force to move the apparatus along the pipeline.
Claim 14
Dependent Claim
96 words
The underwater trenching apparatus of claim 4 including, said roller means including at least one drive roller in driving contact with said pipeline in each of a fore portion of a frame member and in an aft portion of a frame member, drive means for each said drive roller, control means to drive said roller remaining in driving engagement with said pipeline with sufficient force to move the apparatus along the pipeline and prior to the bending of the frame member corresponding to the portion of the frame member having said disengaging other drive roller thereon.
Claim 15
Dependent Claim
196 words
An underwater trenching apparatus for burying pipeline and the like having a pipeline surface obstruction comprising: a frame for positioning about the pipeline to be buried, said frame including frame members positioned on each side of said pipeline, drive rollers connected to at least a fore portion of one of said frame members and to an aft portion of one of said frame members for drive engagement with said pipeline, first disengaging means to selectively alternately disengage at least one of said drive rollers from driving engagement with said pipeline in one portion of said frame member, drive means continuing to drive a drive roller in another portion of said frame member with sufficient force to move said apparatus along said pipeline a sufficient distance whereby said disengaged roller overrides said obstruction on the surface of said pipeline, second disengaging means to selectively and alternately disengage said previously engaged drive roller from said pipeline while said drive means drives said previously disengaged drive roller with sufficient force to move said apparatus along said pipeline, over said obstruction, and cutting means secured to said apparatus for cutting a trench in a formation whereby said pipeline is buried.
Claim 16
Dependent Claim
196 words
An underwater trenching apparatus for burying pipeline and the like having a pipeline surface obstruction comprising: a frame for positioning about the pipeline to be buried, said frame including frame members positioned on each side of said pipeline, drive rollers connected to at least a fore portion of one of said frame members and to an aft portion of one of said frame members for drive engagement with said pipeline, first disengaging means to selectively alternately disengage at least one of said drive rollers from driving engagement with said pipeline in one portion of said frame member, drive means continuing to drive a drive roller in another portion of said frame member with sufficient force to move said apparatus along said pipeline a sufficient distance whereby said disengaged roller overrides said obstruction on the surface of said pipeline, second disengaging means to selectively and alternately disengage said previously engaged drive roller from said pipeline while said drive means drives said previously disengaged drive roller with sufficient force to move said apparatus along said pipeline, over said obstruction, and cutting means secured to said apparatus for cutting a trench in a formation whereby said pipeline is buried.
Claim 17
Dependent Claim
34 words
The underwater trenching apparatus of claim 14 including, pivot means positioned on said apparatus for pivoting each said frame member about a substantially horizontal axis toward and away from roller engagement with said pipeline.
Claim 18
Dependent Claim
41 words
The underwater trenching apparatus of claim 15 including, each frame member having a both fore and aft drive roller, and said disengaging means being a ram connected to the fore and to the aft portions of at least one frame member.
Claim 19
Dependent Claim
32 words
The underwater trenching apparatus of claim 14 including said frame member being relatively rigid but capable of being bent by said disengaging means whereby to selectively and alternately disengage a drive roller.
Claim 20
Dependent Claim
20 words
The underwater trenching apparatus of claim 17 including, each frame member having both a fore and an aft drive roller.
Claim 21
Dependent Claim
29 words
The underwater trenching apparatus of claim 14 including, said disengaging means being a ram connected to the fore and to the aft portions of at least one frame member.
Claim 22
Dependent Claim
51 words
The underwater trenching apparatus of claim 1 including, said roller means being driven by fluid motor means, said fluid motor means including flow divider control means to proportion fluid flow to maintain motivation of selected rollers of said roller means having the greater resistance to moving said apparatus along the pipeline.
Claim 23
Dependent Claim
84 words
The underwater trenching apparatus of claim 1, including, said roller means including at least one drive roller in contact with said pipeline in each of a fore portion of a frame member and in an aft portion of a frame member said roller means being driven by fluid motor means, said fluid motor means including flow divider control means to proportion fluid flow to maintain motivation of selected rollers of said roller means having the greater resistance to moving said apparatus along the pipeline.
Claim 24
Dependent Claim
105 words
The underwater trenching apparatus of claim 1 including, said roller means including at least one drive roller in contact with said pipeline in each of a fore portion of a frame member and in an aft portion of a frame member, drive means for each said drive roller, control means to alternately drive a selected roller in contact with said pipeline with sufficient force to move said apparatus along said pipeline, and said control means including flow divider control means to proportion fluid flow to maintain motivation of selected rollers of said roller means having the greater resistance to moving said apparatus along the pipeline.
Claim 25
Dependent Claim
132 words
The underwater trenching apparatus of claim 1, including, said pivot means including power means connected to said frame member for selectively and independently moving the fore and aft portions of each said frame member toward and away from roller engagement with said pipeline, said roller means including at least one drive roller in contact with said pipeline in each of a fore portion of a frame member and in an aft portion of a frame member, drive means for each said drive roller, driving engagement with said pipeline with sufficient force to move the apparatus along the pipeline, and said control means including flow divider control means to proportion fluid flow to maintain motivation of selected rollers of said roller means having the greater resistance to moving said apparatus along the pipeline.
Claim 26
Dependent Claim
49 words
The underwater trenching apparatus of claim 14, including, said drive means including fluid motor means, said fluid motor means including flow divider control means to proportion fluid flow to maintain motivation of selected rollers of said drive rollers having the greater resistance to moving said apparatus along the pipeline.
Claim 27
Dependent Claim
81 words
The underwater trenching apparatus of claim 14, including, at least one drive roller being in selective contact with said pipeline in each of a fore portion of a frame member and in an aft portion of a frame member, and said drive means including fluid motor means, said fluid motor means including flow divider control means to proportion fluid flow to maintain motivation of selected rollers of said drive rollers having the greater resistance to moving said apparatus along the pipeline.
Claim 28
Dependent Claim
102 words
The underwater trenching apparatus of claim 14, including, said frame member being relatively rigid but capable of being bent by said disengaging means to selectively and alternately disengage a drive roller, at least one driver roller being in selective contact with said pipeline in each of a fore portion of a frame member and in an aft portion of a frame member, and said drive fluid motor means, said fluid motor means including flow divider control means to proportion fluid flow to maintain motivation of selected rollers of said drive rollers having the greater resistance to moving said apparatus along the pipeline.
Claim 29
Dependent Claim
115 words
The underwater trenching apparatus of claim 14 including, said frame member being relatively rigid but capable of being bent by said disengaging means whereby to selectively and alternately disengage a drive roller, at least one drive roller being in selective contact with said pipeline in each of a fore portion of a frame member and in an aft portion of a frame member, said drive means including fluid motor means, said fluid motor means including flow divider control means to proportion fluid flow to maintain motivation of selected rollers of said drive rollers having the greater resistance to moving said apparatus along the pipeline, and each frame member having both fore and aft drive rollers.
Claim 30
Dependent Claim
136 words
The underwater trenching apparatus of claim 14 including, said frame member being relatively rigid but capable of being bent by said disengaging means whereby to selectively and alternately disengage a drive roller, at least one drive roller in selective contact with said pipeline in each of a fore portion of a frame member and in an aft portion of a frame member, said drive means including fluid motor means, said fluid motor means including flow divider control means to proportion fluid flow to maintain motivation of selected rollers of said drive rollers having the greater resistance to moving said apparatus along the pipeline, each frame member having a bore fore and aft drive roller, and said disengaging means being a ram connected to the fore and to the aft portions of at least one frame member.
Claim 31
Dependent Claim
150 words
In an underwater trenching apparatus for burying pipeline and the like having a frame for positioning about the pipeline to be buried, drive rollers positioned fore and aft on said frame for moving the apparatus along the pipeline, drive means for driving said drive rollers and cutting means secured to said apparatus for cutting a formation for burying said pipeline, the improvement for enabling the apparatus to override obstructions in the pipeline surface comprising: control means for said drive means to vary the power directed to said drive rollers, said control means including power flow detection means operatively associated with each fore and aft drive rollers, power flow divider means operatively connected to said power detection means to proportion the power flow to drive selected rollers having the greater resistance to moving said apparatus along the pipeline whereby to enable the apparatus to override the obstruction on the pipeline surface.
Claim 32
Dependent Claim
150 words
In an underwater trenching apparatus for burying pipeline and the like having a frame for positioning about the pipeline to be buried, drive rollers positioned fore and aft on said frame for moving the apparatus along the pipeline, drive means for driving said drive rollers and cutting means secured to said apparatus for cutting a formation for burying said pipeline, the improvement for enabling the apparatus to override obstructions in the pipeline surface comprising: control means for said drive means to vary the power directed to said drive rollers, said control means including power flow detection means operatively associated with each fore and aft drive rollers, power flow divider means operatively connected to said power detection means to proportion the power flow to drive selected rollers having the greater resistance to moving said apparatus along the pipeline whereby to enable the apparatus to override the obstruction on the pipeline surface.
Claim 33
Dependent Claim
34 words
The underwater trenching apparatus of claim 29 including, disengaging means to selectively alternately disengage at least one of said drive rollers from driving engagement with said pipeline in one portion of said frame member.
Claim 34
Dependent Claim
49 words
The underwater trenching apparatus of claim 30 including, second disengaging means to selectively and alternately disengage said previously engaged drive roller from disengagement with said pipeline while said drive means drives said previously disengaged drive roller with sufficient force to move said apparatus along said pipeline, over said obstruction.
Claim 35
Dependent Claim
34 words
The underwater trenching apparatus of claim 29 including, pivot means positioned on said apparatus for pivoting each said frame member about a substantially horizontal axis toward and away from roller engagement with said pipeline.
Claim 36
Dependent Claim
55 words
The underwater trenching apparatus of claim 32 including, said pivot means including power means connected to the fore and aft portions of each said frame member for bending the frame member upon selective moving of one portion of said frame member relative to said pipeline without moving the remaining portions of the same frame member.
Claim 37
Dependent Claim
37 words
The underwater trenching apparatus of claim 32, including, said pivot means including a plurality of power rams for selective movement of the fore and aft portions of each said frame member toward and away from roller engagement.
Claim 38
Dependent Claim
45 words
The underwater trenching apparatus of claim 34 including, said power rams being connected separately to the fore and aft portion of each said frame member for selectively bending said frame member relative to said pipeline without moving the remaining portion of the same frame member.
Claim 39
Dependent Claim
32 words
The underwater trenching apparatus of claim 1 including, said means for moving said pivot means being extensible telescopic means operatively connected to said frame members between said apparatus and said pivot means.
Claim 40
Dependent Claim
82 words
The underwater trenching apparatus of claim 1 including, said pivot means including power means connected to said frame member for selectively and independently moving the fore and aft portions of each said frame member toward and away from roller engagement with said pipeline, said means for moving said pivot means being extensible telescopic means operatively connected to said frame members between said apparatus and said pivot means, and said extensible telescopic means being connected to said frame members above said power means.
Claim 41
Dependent Claim
38 words
The underwater trenching apparatus of claim 1 including, each said frame member having a support bar for said roller means, upright beam means connected to said support bar having bearing means to permit pivoting of said frame member.
Claim 42
Dependent Claim
25 words
The underwater trenching apparatus of claim 1 including, each said frame member receiving a pivot shaft journaled at the ends to form said horizontal axis.
Claim 43
Dependent Claim
24 words
The underwater trenching apparatus of claim 39 including, extensible telescopic means to move the frame members transversely being connected to each pivot shaft means.
Claim 44
Dependent Claim
38 words
The underwater trenching apparatus of claim 40 including, said extensible telescopic means operatively connected to said frame members and extending from said apparatus to said pivot shaft for lateral movement of said pivot shaft and said horizontal axis.
Claim 45
Dependent Claim
22 words
The underwater trenching apparatus of claim 41 including, said extensible telescopic means being connected to said frame members above said power means.
Claim 46
Dependent Claim
86 words
The underwater trenching apparatus of claim 38 including, each said frame member receiving a pivot shaft journaled at the ends to form said horizontal axis, extensible telescopic means to move the frame members transversely being connected to each pivot shaft means, said extensible telescopic means operatively connected to said frame members and extending from said apparatus to said pivot shaft for lateral movement of said pivot shaft and said horizontal axis, and said extensible telescopic means being connected to said frame members above said power means.
Claim 47
Dependent Claim
123 words
The underwater trenching apparatus of claim 1 including, each said frame member having support means for said roller means, said roller means including drive rollers positioned fore and aft on said frame member, upright members connected to said drive roller support means, said pivot means including a pivot shaft journaled within said upright members, said means for moving said pivot means being extensible telescopic means operatively connected to said frame members between said apparatus and said pivot means, and said pivot means including a plurality of power means operatively connected to said frame members below said means for moving said pivot means, whereby to achieve selective movement of the fore and aft portions of each frame member toward and away from roller engagement.
Claim 48
Dependent Claim
40 words
The underwater trenching apparatus of claim 44 including, said pivot means being selectively operable upon either or both the fore and aft portions of the frame member to move selectively one or more said portions to bend said frame member.
Claim 49
Dependent Claim
40 words
The underwater trenching apparatus of claim 45 including, each said frame member having a support bar for said drive roller means, and upright beam means connected to said support bar having bearing means to permit pivoting of said frame member.
Claim 50
Dependent Claim
40 words
The underwater trenching apparatus of claim 44 including, each said frame member having a support bar for said drive roller means, and upright beam means connected to said support bar having bearing means to permit pivoting of said frame member.
Claim 51
Dependent Claim
48 words
The underwater trenching apparatus of claim 44 including, said power means including first and second disengaging means to selectively and alternately disengage at least one of said drive rollers from said pipeline while another roller remains in contact with said pipeline and moves said apparatus along said pipeline.
Claim 52
Dependent Claim
38 words
The underwater trenching apparatus of claim 44 including said power means including disengaging means to selectively alternately disengage at least one of said drive rollers from driving engagement with said pipeline in one portion of said frame member.
Claim 53
Dependent Claim
47 words
The underwater trenching apparatus of claim 49 including, second disengaging means to selectively and alternately disengage said previously engaged drive roller from said pipeline while said drive means drives said previously disengaged drive roller with sufficient force to move said apparatus along said pipeline, over said obstruction.
Claim 54
Dependent Claim
39 words
The underwater trenching apparatus of claim 14 including, each said frame member having a support bar for said drive roller, and upright beam means connected to said support bar having bearing means to permit pivoting of said frame member.
Claim 55
Dependent Claim
39 words
The underwater trenching apparatus of claim 15 including, each said frame member having a support bar for said drive roller, and upright beam means connected to said support bar having bearing means to permit pivoting of said frame member.
Claim 56
Dependent Claim
128 words
In a method of underwater trenching of a bottom formation for burying a pipeline by jetting a trench with an apparatus having frame members supported on the pipeline and driven by fore and aft pipeline engaging drive rollers, the improvement comprising, contacting the pipeline with the drive rollers in driving engagement, selectively and disengaging a forwardly positioned drive roller from driving engagement with said pipeline, driving an aft positioned drive roller to enable said forward drive roller to move forwardly along said pipeline and override an obstruction on the pipeline surface, selectively disengaging said aft positioned drive roller from driving engagement with said pipeline, engaging said forward drive roller in drive engagement with said pipeline to move said aft drive roller above said pipeline and override said obstruction.
Claim 57
Dependent Claim
128 words
In a method of underwater trenching of a bottom formation for burying a pipeline by jetting a trench with an apparatus having frame members supported on the pipeline and driven by fore and aft pipeline engaging drive rollers, the improvement comprising, contacting the pipeline with the drive rollers in driving engagement, selectively and disengaging a forwardly positioned drive roller from driving engagement with said pipeline, driving an aft positioned drive roller to enable said forward drive roller to move forwardly along said pipeline and override an obstruction on the pipeline surface, selectively disengaging said aft positioned drive roller from driving engagement with said pipeline, engaging said forward drive roller in drive engagement with said pipeline to move said aft drive roller above said pipeline and override said obstruction.
Claim 58
Dependent Claim
37 words
The method of claim 53 including, selectively and alternately opening and closing fore and aft portions of said frame members to selectively and alternately disengage driving engagement of a drive roller in a fore or aft position.
Claim 59
Dependent Claim
40 words
The method of claim 53 including applying a force selectively and alternately to a frame member to bend said frame member to selectively and alternately engage and disengage driving engagement of a drive roller in a fore or aft position.
Claim 60
Independent Claim
91 words
A method of underwater trenching of a bottom with an apparatus having frame members supported on the pipeline and driven by fore and aft pipeline engaging drive rollers, the improvement comprising, detecting the amount of power directed to said drive rollers controling said drive rollers to vary power directed to said drive rollers, directing and dividing power to selected fore or aft drive rollers to maintain movement of said drive roller in driving engagement with said pipeline, whereby said apparatus moves along said pipeline to override obstructions on the pipeline surface.
Claim 61
Independent Claim
91 words
A method of underwater trenching of a bottom with an apparatus having frame members supported on the pipeline and driven by fore and aft pipeline engaging drive rollers, the improvement comprising, detecting the amount of power directed to said drive rollers controling said drive rollers to vary power directed to said drive rollers, directing and dividing power to selected fore or aft drive rollers to maintain movement of said drive roller in driving engagement with said pipeline, whereby said apparatus moves along said pipeline to override obstructions on the pipeline surface.
Claim 62
Dependent Claim
69 words
The method of claim 56 comprising, driving an aft positioned drive roller to enable said forward drive roller to move downwardly along said pipeline and override an obstruction on the pipeline surface, selectively disengaging said aft positioned drive roller from driving engagement with said pipeline, engaging said forward drive roller in drive engagement with said pipeline to move said aft drive roller above said pipeline and override said obstruction.
Claim 63
Dependent Claim
37 words
The method of claim 56 comprising, selectively and alternately opening and closing fore and aft portions of said frame members to selectively and alternately disengage driving engagement of a drive roller in a fore or aft position.
Claim 64
Dependent Claim
40 words
The method of claim 56 comprising, applying a force selectively and alternately to a frame member to bend said frame member to selectively and alternately engage and disengaged driving engagement of a drive roller in a fore or aft position.
Claim 65
Dependent Claim
100 words
The method of claim 56 comprising, driving an aft positioned drive roller to enable said forward drive roller to move downwardly along said pipeline and override an obstruction on the pipeline surface, selectively disengaging said aft positioned drive roller from driving engagement with said pipeline, engaging said forward drive roller in drive engagement with said pipeline to move said aft drive roller above said pipeline and override said obstruction, selectively and alternately opening and closing fore and aft portions of said frame members to selectively and alternately disengage driving engagement of a drive roller in a fore or aft position.
Claim 66
Dependent Claim
134 words
The method of claim 56 comprising, driving an aft positioned drive roller to enable said forward drive roller to move downwardly along said pipeline and override an obstruction on the pipeline surface, selectively disengaging said aft positioned drive roller from driving engagement with said pipeline, engaging said forward drive roller in drive engagement with said pipeline to move said aft drive roller above said pipeline and override said obstruction, selectively and alternately opening and closing fore and aft portions of said frame members to selectively and alternately disengage driving engagement of a drive roller in a fore or aft position, applying a force selectively and alternately to a frame member to bend said frame member to selectively and alternately engage and disengage driving engagement of a drive roller in a fore or aft position.
Claim 67
Dependent Claim
24 words
The apparatus of claim 1 including, said roller means including guide means positioned intermediate said cutting means to guide said apparatus along said pipeline.
Claim 68
Dependent Claim
72 words
The apparatus of claim 62 including, said guide means being forwardly positioned drive rollers, said cutting means including forward cutting jets in front of said forwardly positioned drive rollers to clear a shallow trench in said formation, and rearward cutting jets extending below said forward jets and aft of said forward drive rollers, said rearward cutting jets extending downwardly below said pipeline to cut said trench for said pipeline to be buried.
Claim 69
Dependent Claim
36 words
The apparatus of claim 14 including, said drive rollers connected to said fore portion of said frame members being forwardly positioned and providing guide means intermediate said cutting means to guide said apparatus along said pipeline.
Claim 70
Dependent Claim
72 words
The apparatus of claim 64 including, said guide means being forwardly positioned drive rollers, said cutting means including forward cutting jets in front of said forwardly positioned drive rollers to clear a shallow trench in said formation, and rearward cutting jets extending below said forward jets and aft of said forward drive rollers, said rearward cutting jets extending downwardly below said pipeline to cut said trench for said pipeline to be buried.
Claim 71
Dependent Claim
36 words
The apparatus of claim 29 including, said drive rollers connected to said fore portion of said frame members being forewardly positioned and providing guide means intermediate said cutting means to guide said apparatus along said pipeline.
Claim 72
Dependent Claim
72 words
The apparatus of claim 66 including, said guide means being forwardly positioned drive rollers, said cutting means including forward cutting jets in front of said forwardly positioned drive rollers to clear a shallow trench in said formation, and rearward cutting jets extending below said forward jets and aft of said forward drive rollers, said rearward cutting jets extending downwardly below said pipeline to cut said trench for said pipeline to be buried.
Claim 73
Dependent Claim
63 words
The method of claim 53 including, providing forward cutting jets on said apparatus in front of said fore drive rollers and rearward jets aft of said fore drive rollers, cutting a shallow and wide trench with said forward cutting jets, guiding said apparatus along said pipeline with said fore drive rollers while cutting a deep and narrower trench with said rearward cutting jets.