CA2354737A1 - Method and apparatus for cutting and splitting pipe - Google Patents
Method and apparatus for cutting and splitting pipe Download PDFInfo
- Publication number
- CA2354737A1 CA2354737A1 CA002354737A CA2354737A CA2354737A1 CA 2354737 A1 CA2354737 A1 CA 2354737A1 CA 002354737 A CA002354737 A CA 002354737A CA 2354737 A CA2354737 A CA 2354737A CA 2354737 A1 CA2354737 A1 CA 2354737A1
- Authority
- CA
- Canada
- Prior art keywords
- pipe
- cutting
- culvert
- wall
- wheels
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
- B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
- B21C37/12—Making tubes or metal hoses with helically arranged seams
- B21C37/127—Tube treating or manipulating combined with or specially adapted for use in connection with tube making machines, e.g. drawing-off devices, cutting-off
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
- B23D21/00—Machines or devices for shearing or cutting tubes
- B23D21/02—Machines or devices for shearing or cutting tubes otherwise than in a plane perpendicular to the axis of the tube, e.g. for making mitred cuts, for making bicycle frames
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
- B26D3/00—Cutting work characterised by the nature of the cut made; Apparatus therefor
- B26D3/001—Cutting tubes longitudinally
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
- F16L55/16—Devices for covering leaks in pipes or hoses, e.g. hose-menders
- F16L55/162—Devices for covering leaks in pipes or hoses, e.g. hose-menders from inside the pipe
- F16L55/165—Devices for covering leaks in pipes or hoses, e.g. hose-menders from inside the pipe a pipe or flexible liner being inserted in the damaged section
- F16L55/1658—Devices for covering leaks in pipes or hoses, e.g. hose-menders from inside the pipe a pipe or flexible liner being inserted in the damaged section the old pipe being ruptured prior to insertion of a new pipe
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Forests & Forestry (AREA)
- Excavating Of Shafts Or Tunnels (AREA)
Description
TEM Docket No. 235.2 TITLE: METHOD AND APPARATUS FOR CUTTING AND SPLITTING PIPE
FIELD OF THE INVENTION
The present invention relates to a cutting, expanding, and re-piping apparatus that permits the in situ replacement of an existing corrugated metal pipe or thin walled pipe used for culverts by cutting and expanding the host pipe to permit a re-placement pipe to be drawn through the host pipe. More specifically, the invention is directed for use on 1o corrugated metal piping or thin-wall piping used for culverts under roads where the culvert has deteriorated over time, has lost some of its structural integrity or has partially collapsed, thereby losing its original circular shape.
BACKGROUND OF THE INVENTION
1s Existing underground or buried pipe, such as culverts or water and gas mains, are typically replaced for various reasons, such as the impending expiry of the pipe's service life, the failure or deterioration of the existing pipe, and the insufficient size/capacity of the existing pipe. Removal of such "old" pipe is avoided, if possible, to avoid prohibitive excavation costs and other related expenses and inconveniences, such as repaying a road 2o surface and closing the road to vehicular traffic.
Various devices and techniques have therefore been developed for in situ replacement of buried pipe to reduce costs and inconveniences. Examples of such tools to cut through an existing pipe from within, particularly those employing a form of cutting means such as cutting wheels or blades, are shown in US patents 5,098,225 2s (Rockower et al.) and 6,149,346 (Takamatsu et al.). However, a disadvantage of such prior art cutting tools is that they are dependent upon the concentricity and structural integrity of the pipe since such tools utilize offsetting forces to attain the cut or split. In Rockower and Takamatsu the cutting wheels or bodies will not cut through a longitudinal section of deteriorated pipe unless the cutting wheels/bodies have sufficient radial force to push through the pipe. For instance, in Rockower, the cutting wheels at the bottom of the cutting tool will not be able to push downwardly and cut through a bottom portion of s intact pipe if the opposed ceiling portion of the pipe has deteriorated and does not provide sufficient support for such downward forces. Hence, it is difficult, if not impossible, to expediently and properly split a deteriorated pipe lacking structural integrity with current cutting tools since the pipe will lose its concentricity and be incapable of supplying the necessary offsetting forces.
1o In another type of pipe replacement apparatus shown in US patent 5,112, I
(McConnell), a crushing head has circumferentially disposed tapered blades for crushing an existing pipe. Such apparatus will also encounter difficulties with deteriorated pipe because the crushing head will be forced off centre of the pipe and may jam if the blades encounter non-uniform resistance from the deteriorated pipe walls.
15 What is therefore desired is a novel pipe cutting tool that overcomes the limitations and disadvantages of the existing tools. Preferably, it should be able to cut through a pipe regardless of the pipe's structural integrity. All of the required cutting forces should be offset internally within the cutting tool itself. The same cutting tool should be capable of use for various sizes of pipes, to avoid the cost of stocking various 2o sizes of cutters for different pipes. The tool should be adapted to cut through external culvert obstructions, such as joining clamps, which traditionally have been problematic for conventional tools. Further, a user should have the option of using more than one cutting tool concurrently in a pipe to provide a desired number of longitudinal cuts, so as to easily and quickly adapt to the size and integrity of the pipe, and to the existing soil 25 conditions.
FIELD OF THE INVENTION
The present invention relates to a cutting, expanding, and re-piping apparatus that permits the in situ replacement of an existing corrugated metal pipe or thin walled pipe used for culverts by cutting and expanding the host pipe to permit a re-placement pipe to be drawn through the host pipe. More specifically, the invention is directed for use on 1o corrugated metal piping or thin-wall piping used for culverts under roads where the culvert has deteriorated over time, has lost some of its structural integrity or has partially collapsed, thereby losing its original circular shape.
BACKGROUND OF THE INVENTION
1s Existing underground or buried pipe, such as culverts or water and gas mains, are typically replaced for various reasons, such as the impending expiry of the pipe's service life, the failure or deterioration of the existing pipe, and the insufficient size/capacity of the existing pipe. Removal of such "old" pipe is avoided, if possible, to avoid prohibitive excavation costs and other related expenses and inconveniences, such as repaying a road 2o surface and closing the road to vehicular traffic.
Various devices and techniques have therefore been developed for in situ replacement of buried pipe to reduce costs and inconveniences. Examples of such tools to cut through an existing pipe from within, particularly those employing a form of cutting means such as cutting wheels or blades, are shown in US patents 5,098,225 2s (Rockower et al.) and 6,149,346 (Takamatsu et al.). However, a disadvantage of such prior art cutting tools is that they are dependent upon the concentricity and structural integrity of the pipe since such tools utilize offsetting forces to attain the cut or split. In Rockower and Takamatsu the cutting wheels or bodies will not cut through a longitudinal section of deteriorated pipe unless the cutting wheels/bodies have sufficient radial force to push through the pipe. For instance, in Rockower, the cutting wheels at the bottom of the cutting tool will not be able to push downwardly and cut through a bottom portion of s intact pipe if the opposed ceiling portion of the pipe has deteriorated and does not provide sufficient support for such downward forces. Hence, it is difficult, if not impossible, to expediently and properly split a deteriorated pipe lacking structural integrity with current cutting tools since the pipe will lose its concentricity and be incapable of supplying the necessary offsetting forces.
1o In another type of pipe replacement apparatus shown in US patent 5,112, I
(McConnell), a crushing head has circumferentially disposed tapered blades for crushing an existing pipe. Such apparatus will also encounter difficulties with deteriorated pipe because the crushing head will be forced off centre of the pipe and may jam if the blades encounter non-uniform resistance from the deteriorated pipe walls.
15 What is therefore desired is a novel pipe cutting tool that overcomes the limitations and disadvantages of the existing tools. Preferably, it should be able to cut through a pipe regardless of the pipe's structural integrity. All of the required cutting forces should be offset internally within the cutting tool itself. The same cutting tool should be capable of use for various sizes of pipes, to avoid the cost of stocking various 2o sizes of cutters for different pipes. The tool should be adapted to cut through external culvert obstructions, such as joining clamps, which traditionally have been problematic for conventional tools. Further, a user should have the option of using more than one cutting tool concurrently in a pipe to provide a desired number of longitudinal cuts, so as to easily and quickly adapt to the size and integrity of the pipe, and to the existing soil 25 conditions.
2 SUMMARY OF THE PRESENT INVENTION
According to the present invention, there is provided in one aspect a cutting apparatus which is adapted to cut corrugated metal pipe or thin walled pipe regardless of the pipe's concentricity and structural integrity as all required forces are offset internally s within the cutting tool. The apparatus accomplishes this with a series of cutting wheels, stepped in stages, mounted in a frame which envelopes one or more portions of the pipe wall and is drawn through the pipe to cut a specific logitudinal portion of the pipe without relying on or touching other portions of the pipe. The present apparatus relies on pressure between its frame and cutting wheels when pulled along the wall of the pipe, thus 1o eliminating the pipe's size and total structural integrity as prereqisites for using the device on the pipe.
In particular, the present device includes a guide for the device's frame which provides several advantages, including:
providing the frame with a larger area of contact with the pipe wall to allow the ~s cutter apparatus to follow the pipe wall regardless of the pipe's shape;
creating a channel for the cutter wheels beyond the diameter of the pipe; and, preventing debris from falling into the cavity of the pipe while cutting the pipe wall.
The leading edge of the frame of the present apparatus is hardened and sharpened 2o to shear any exterior bolts or bonding used to hold pipes together. Behind the cutter wheels is a sharpened, hardened ripper to ensure any uncut metal is severed.
For mobility, the cutter head is attached to a traveling link, connected to a pull string, which allows the head to follow along the pipe wall independently of any irregularities. A
chassis attached to the pull string is adjustable for different diameter culverts to allow for 25 alignment of the cutter apparatus with the pipe wall.
An expanding head travels behind the cutting apparatus to spread the cut pipe and make room for a new replacement pipe to be drawn through.
According to the present invention, there is provided in one aspect a cutting apparatus which is adapted to cut corrugated metal pipe or thin walled pipe regardless of the pipe's concentricity and structural integrity as all required forces are offset internally s within the cutting tool. The apparatus accomplishes this with a series of cutting wheels, stepped in stages, mounted in a frame which envelopes one or more portions of the pipe wall and is drawn through the pipe to cut a specific logitudinal portion of the pipe without relying on or touching other portions of the pipe. The present apparatus relies on pressure between its frame and cutting wheels when pulled along the wall of the pipe, thus 1o eliminating the pipe's size and total structural integrity as prereqisites for using the device on the pipe.
In particular, the present device includes a guide for the device's frame which provides several advantages, including:
providing the frame with a larger area of contact with the pipe wall to allow the ~s cutter apparatus to follow the pipe wall regardless of the pipe's shape;
creating a channel for the cutter wheels beyond the diameter of the pipe; and, preventing debris from falling into the cavity of the pipe while cutting the pipe wall.
The leading edge of the frame of the present apparatus is hardened and sharpened 2o to shear any exterior bolts or bonding used to hold pipes together. Behind the cutter wheels is a sharpened, hardened ripper to ensure any uncut metal is severed.
For mobility, the cutter head is attached to a traveling link, connected to a pull string, which allows the head to follow along the pipe wall independently of any irregularities. A
chassis attached to the pull string is adjustable for different diameter culverts to allow for 25 alignment of the cutter apparatus with the pipe wall.
An expanding head travels behind the cutting apparatus to spread the cut pipe and make room for a new replacement pipe to be drawn through.
3 All of the aforementioned aspects of the present invention are connected to each other at end of a pull string.
Depending on soil and pipe conditions, one or more cutting tools can be employed at the end of the pull string to provide a corresponding number of longitudinal cuts s through the pipe.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein:
Figure 1 shows a cutting, expanding and re-piping assembly according to a preferred embodiment of the present invention in operation, namely a pull string pulling a cutting tool through an existing culvert, and an expanding head and collar with a new culvert being drawn therewith;
Figure 1 a is a view similar to fig. l showing a shorter coupler for using the cutting 1s tool in an existing culvert of smaller diameter;
Figure 2 is a more detailed elevational view of the cutting tool of fig. l ;
Figure 2a is a view similar to fig.2 showing the frame of the cutting tool with cutting wheels removed;
Figure 3 is a plan view from above of the cutting tool of fig.2;
2o Figure 4 is a view from the bottom of the cutting tool of fig.2;
Figure 5 is a end view from the front of the cutting tool of fig.2;
Figure Sa is a viw similar to fig.5 showing the frame of the cutting tool with the cutting wheels removed;
Figure 6 is a cross-sectional view along line 6-6 of fig.2;
2s Figure 7 is a detailed elevational view of one of the cutting wheels of the cutting tool of fig.2;
Figure 8 is a cross-sectional view of the cutting wheel of fig.7; and,
Depending on soil and pipe conditions, one or more cutting tools can be employed at the end of the pull string to provide a corresponding number of longitudinal cuts s through the pipe.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein:
Figure 1 shows a cutting, expanding and re-piping assembly according to a preferred embodiment of the present invention in operation, namely a pull string pulling a cutting tool through an existing culvert, and an expanding head and collar with a new culvert being drawn therewith;
Figure 1 a is a view similar to fig. l showing a shorter coupler for using the cutting 1s tool in an existing culvert of smaller diameter;
Figure 2 is a more detailed elevational view of the cutting tool of fig. l ;
Figure 2a is a view similar to fig.2 showing the frame of the cutting tool with cutting wheels removed;
Figure 3 is a plan view from above of the cutting tool of fig.2;
2o Figure 4 is a view from the bottom of the cutting tool of fig.2;
Figure 5 is a end view from the front of the cutting tool of fig.2;
Figure Sa is a viw similar to fig.5 showing the frame of the cutting tool with the cutting wheels removed;
Figure 6 is a cross-sectional view along line 6-6 of fig.2;
2s Figure 7 is a detailed elevational view of one of the cutting wheels of the cutting tool of fig.2;
Figure 8 is a cross-sectional view of the cutting wheel of fig.7; and,
4 Figure 9 is an end view looking into a culvert with three cutting tools employed therein.
LIST
OF
REFERENCE
NUMERALS
IN
DRAWINGS
s 10 cutting apparatus/tool 12 existing culvert/pipe 14 centerline of 12 16 ground/soil 18 new culvert/pipe 1o 20 pull string 22 chassis portion of 20 24 coupling plate 25 bolts 26 travelling block is 30 expanding head 32 collar 40 frame of 10 42 nose of 40 44 lower lip 2o 46 upper lip 47 edge of 46 48 mouth 50 guide SOa, SOb plates 2s 52 longitudinal channel 54 opening 56 ripper 58 leading edge of 46 58a, 58b portions of 58 60 handle 62 bolt holes in 44 70 cutting wheels 70a-70e first to last cutting wheel 72 outer perimeter of 70 74 nut and bolt arrangement 76 bore DESCRIPTION OF PREFERRED EMBODIMENTS
Figure 1 shows an apparatus for cutting and splitting pipe according to a preferred embodiment of the present invention, generally designated by reference numeral 10 and usually referred to herein as a "cutting tool", being drawn along the wall of an old, or existing, culvert 12 by a pulling means such as a pull string 20. The existing culvert 12, also be referred to herein as "pipe", may comprise oiUgas pipelines, water lines, sewer pipes, gas mains, and the like, which are buried in the ground 16 or are located above-ground. The preferred embodiment of the cutting tool 10 is best suited for use on metallic pipes that are traditionally difficult to cut, such as corrugated metal pipe.
2o However, the apparatus is also well suited for smooth walled metal pipes and, as will be appreciated later, pipes of different materials.
An expanding device 30 having a conical head of conventional design is linked to the pull string 20 and travels behind the cutting apparatus 10 through the existing cut pipe to further expand and spread the pipe and surrounding soil as is known in the art. The expanding head 30 makes room for a new/replacement corrugated culvert/pipe 18.
The new pipe 18 is connected behind the head 30 via suitable means, such as a collar 32. In addition, the expanding head 30 may take other, non-conical shapes, depending on the configuration of the new pipe to be installed.
The cutting apparatus 10, expanding head 30, collar 32 and new culvert 18 are all operatively engaged to the end of the pull string 20 which is located generally along the longitudinal centerline 15 of the old culvert 12. The pull string 20 is pulled at a downstream location of the old culvert by suitable pulling means for exerting adequate force to pull the entire assembly through the ground. An important feature of the pull string 20 is a relatively solid chassis portion 22 and a triangular coupling plate 24 fixed thereto by suitable means, such as bolts 25. A traveling link 26 is pivotally coupled at 1o one end to the top of the coupling plate 24 and at the other end to the nose of the cutting apparatus at 42. As will be appreciated better later, the link 26 provides the cutting apparatus 10 with some freedom of movement radially to allow the apparatus to follow corrugations and other imperfections and irregularities on the old culvert wall 12. The height of the coupling plate 24, as well as the length of the link 26, may be appropriately is varied to fit the cutting apparatus in culverts of various sizes/diameters.
For example, the shorter ("shallower") coupling plate 24 in fig. l a would be used for a pipe of smaller diameter than the taller plate 24 for the larger pipe of fig. l .
Another important feature of the present invention is the configuration and function of the cutting apparatus, as shown in fig.l and in greater detail in figs.2 to 8.
2o The location of the various features of the cutting apparatus relative to each another will be described based on the orientation of the apparatus at the top of the culvert as shown in the figures. It should be understood that the described locations would change for an apparatus oriented in a different manner, say upside down on the lower part of the old culvert.
25 The cutting apparatus 10, also referred to herein as a cutting "tool", has a frame 40 (as best seen in figs. 2a and Sa) with a series of metallic cutting wheels, generally indicated by 70, spaced in tandem relationship along a lower elongate lip 44 of the frame 40. Although it is contemplated that hardened steel wheels will be most commonly used, wheels made of other suitable materials, such as ceramic, may be employed for other applications. The frame has an opposed upper elongate lip 46 spaced above the lower lip 44 to define an elongate longitudinal mouth 48 forming an opening of suitable size to s accept most thicknesses of culvert walls 12. Two elongate plates SOa and SOb, one extending transversely from either side of the upper lip 46, form a frame guide 50 above the mouth 48 along most of its length. The guide 50 provides an enlarged area of contact between the culvert wall and the frame to make it easier for the frame to follow the culvert wall regardless of its shape. The bottom surface of each plate SOa, SOb extends to slightly below the edge 47 of the upper lip to form a longitudinal channel 52 (best viewed in figs.2 and 5) for the back cutting wheels which extend across the mouth and beyond the radial extent of the culvert's wall. The guide 50 also prevents debris, such as soil from the ground above the pipe, from falling past the cutting apparatus into the inner cavity of the pipe being cut open.
15 The cutting wheels 70, which are individually designated by reference numerals 70a to 70e, are rotatably mounted along the lower lip 44 by suitable means, such as the nut and bolt/axle arrangement 74 which operationally engages the wheel's bore 76, shown in figs.6-8. The wheels 70a-70e are arranged so that they are stepped in stages upwardly toward the upper lip 46, and more particularly toward the channel 52 of the 2o body 40, progressively from the mouth's front opening toward its back throat. In the preferred embodiment the outer perimeter 72 of the first cutting wheel 70a (which first engages the wall of the existing culvert wall as it enters the mouth) extends the least distance from the lower lip 44 into the mouth 48. In contrast, the outer perimeter of the last, or fifth, cutting wheel 70e extends the furthest from the lower lip 44 and across the 2s mouth 48 into the channel 52 of the upper lip, in close proximity to the base of the channel. In the embodiment shown, the first three wheels 70a-70c are of the same size, but the bolt holes 62 (see fig.2a) are spaced progressively closer to the mouth 48 to bring the perimeter of the cutting wheels 70a-70c progressively closer to the upper lip. The fourth cutting wheel 70d is of greater diameter than wheels 70a-70c so that its outer perimeter is yet closer to the upper lip than wheel 70c. Finally, the fifth cutting wheel 70e has a greater diameter than wheel 70d to bring its perimeter closest to the frame's upper lip. It will be understood that other configurations of wheel sizes and bolt hole locations are possible to achieve a progressive cut of the pipe wall within the mouth 48.
As the cutting apparatus is drawn into contact with the culvert wall, the cutting wheels apply a progressively greater pressure on the wall to cut therethrough.
By the time that the last wheel 70e engages the cut being formed in the wall, the wall should be at least nearly or fully severed. As a "fail-safe" precaution, an inclined elongate opening 54 extends from the back of the mouth 48 behind the last cutting wheel 70e to present a hardened, sharpened lower edge, termed a "ripper" 56. The ripper ensures that any uncut culvert wall that might pass the last wheel 70e will be severed as the cutting tool is pulled through the existing culvert.
1s The leading edge 58 of the upper lip 46 has an upward pitch from the front to the back of the frame 40, with a steeper nose portion 58a and a more gradually sloped spinal portion 58b. The leading edge is hardened and sharpened for shearing any exterior obstructions that are encountered along the culvert's wall, such as exterior bolts or banding for joining sections of the culvert, and for pushing aside the ground through 2o which the frame 40 travels. An elongate hole 60 further along the spine toward the back of the frame forms a handle for a user to grip and lift the tool by hand.
As shown in fig.9, more than one cutting tool may be mounted on an existing culvert to provide a corresponding number of longitudinal cuts therethrough.
The number of cutting tools used will be determined by prior inspection and site conditions, such as 2s the condition of the soil and of the culvert.
An example of the typical operation of the present invention may now be illustrated. Once one end of a culvert is located and, if need be, excavated to expose the inlet, the cutting tool's mouth is slid onto the culvert wall and is pushed on as far as it will go until the cutting wheels resist further movement. The pull string 20 should already be passed through to the other end of the culvert where the cutting is to finish, and the nose 42 of the tool should be attached to a coupling plate 24 and traveling link 26 of s suitable size for the diameter of culvert to be cut. The number of cutting tools to be used is determined based on the earlier mentioned criteria. The expanding head 30 is connected to the end of the pull string just behind the cutting tool, and the new culvert is in turn connected to the expanding head via the collar 32. Force is then exerted on the far end of the pull string to draw the cutting tool longitudinally further onto the culvert wall.
1o The cutting wheels 70 engage the wall with greater force and progressively push the wall toward the upper lip 46, and in doing so the wheels form a cut through the wall, thereby severing the culvert. The expanding head then spreads the severed culvert and draws in the new culvert as is known in the art. As the cutting tool travels along the culvert, the lower lip 44 remains inside the culvert while the upper lip 46 remains outside the culvert.
1s Hence, the frame's leading edge 58 pushes aside the ground and severs any external pipe obstructions that are encountered, such as external bolts.
An important advantage of the cutting tool is its ability to cut through the culvert wall regardless of the culvert's structural integrity. The cutting tool 10 does not rely on structural support from other portions of the culvert to counteract cutting forces. Rather, 2o the upward forces of the cutting wheels 70 on the culvert wall are counteracted, or resisted, by the opposed upper lip 44 of the frame. Hence, all of the required cutting forces are offset "internally" within the cutting tool itself.
Another advantage of the present invention is the ability to use the same cutting tool for various sizes of culverts. As long as the thickness of the culvert wall can be 2s accommodated within the mouth 48 of the cutting tool, a user need only provide a suitably sized coupling plate 24 and/or travelling link 26 for the choosen culvert. Hence, a user is able to avoid the needless cost of stocking various sizes of cutters and of transporting several sizes of cutters to a work site.
Yet another advantage is that the leading edge 58 is adapted to effectively cut through external culvert obstructions which traditionally have been problematic for s conventional tools.
A further advantage is the ability to use more than one cutting tool during a single pass through an existing culvert to provide the desired number of longitudinal cuts.
Hence the apparatus is easily and quickly adapted at a work site to the size and integrity the particular pipe, as well as the existing soil conditions.
1o The above description is intended in an illustrative rather than a restrictive sense, and variations to the specific configurations described may be apparent to skilled persons in adapting the present invention to other specific applications. Such variations are intended to form part of the present invention insofar as they are within the spirit and scope of the claims below.
LIST
OF
REFERENCE
NUMERALS
IN
DRAWINGS
s 10 cutting apparatus/tool 12 existing culvert/pipe 14 centerline of 12 16 ground/soil 18 new culvert/pipe 1o 20 pull string 22 chassis portion of 20 24 coupling plate 25 bolts 26 travelling block is 30 expanding head 32 collar 40 frame of 10 42 nose of 40 44 lower lip 2o 46 upper lip 47 edge of 46 48 mouth 50 guide SOa, SOb plates 2s 52 longitudinal channel 54 opening 56 ripper 58 leading edge of 46 58a, 58b portions of 58 60 handle 62 bolt holes in 44 70 cutting wheels 70a-70e first to last cutting wheel 72 outer perimeter of 70 74 nut and bolt arrangement 76 bore DESCRIPTION OF PREFERRED EMBODIMENTS
Figure 1 shows an apparatus for cutting and splitting pipe according to a preferred embodiment of the present invention, generally designated by reference numeral 10 and usually referred to herein as a "cutting tool", being drawn along the wall of an old, or existing, culvert 12 by a pulling means such as a pull string 20. The existing culvert 12, also be referred to herein as "pipe", may comprise oiUgas pipelines, water lines, sewer pipes, gas mains, and the like, which are buried in the ground 16 or are located above-ground. The preferred embodiment of the cutting tool 10 is best suited for use on metallic pipes that are traditionally difficult to cut, such as corrugated metal pipe.
2o However, the apparatus is also well suited for smooth walled metal pipes and, as will be appreciated later, pipes of different materials.
An expanding device 30 having a conical head of conventional design is linked to the pull string 20 and travels behind the cutting apparatus 10 through the existing cut pipe to further expand and spread the pipe and surrounding soil as is known in the art. The expanding head 30 makes room for a new/replacement corrugated culvert/pipe 18.
The new pipe 18 is connected behind the head 30 via suitable means, such as a collar 32. In addition, the expanding head 30 may take other, non-conical shapes, depending on the configuration of the new pipe to be installed.
The cutting apparatus 10, expanding head 30, collar 32 and new culvert 18 are all operatively engaged to the end of the pull string 20 which is located generally along the longitudinal centerline 15 of the old culvert 12. The pull string 20 is pulled at a downstream location of the old culvert by suitable pulling means for exerting adequate force to pull the entire assembly through the ground. An important feature of the pull string 20 is a relatively solid chassis portion 22 and a triangular coupling plate 24 fixed thereto by suitable means, such as bolts 25. A traveling link 26 is pivotally coupled at 1o one end to the top of the coupling plate 24 and at the other end to the nose of the cutting apparatus at 42. As will be appreciated better later, the link 26 provides the cutting apparatus 10 with some freedom of movement radially to allow the apparatus to follow corrugations and other imperfections and irregularities on the old culvert wall 12. The height of the coupling plate 24, as well as the length of the link 26, may be appropriately is varied to fit the cutting apparatus in culverts of various sizes/diameters.
For example, the shorter ("shallower") coupling plate 24 in fig. l a would be used for a pipe of smaller diameter than the taller plate 24 for the larger pipe of fig. l .
Another important feature of the present invention is the configuration and function of the cutting apparatus, as shown in fig.l and in greater detail in figs.2 to 8.
2o The location of the various features of the cutting apparatus relative to each another will be described based on the orientation of the apparatus at the top of the culvert as shown in the figures. It should be understood that the described locations would change for an apparatus oriented in a different manner, say upside down on the lower part of the old culvert.
25 The cutting apparatus 10, also referred to herein as a cutting "tool", has a frame 40 (as best seen in figs. 2a and Sa) with a series of metallic cutting wheels, generally indicated by 70, spaced in tandem relationship along a lower elongate lip 44 of the frame 40. Although it is contemplated that hardened steel wheels will be most commonly used, wheels made of other suitable materials, such as ceramic, may be employed for other applications. The frame has an opposed upper elongate lip 46 spaced above the lower lip 44 to define an elongate longitudinal mouth 48 forming an opening of suitable size to s accept most thicknesses of culvert walls 12. Two elongate plates SOa and SOb, one extending transversely from either side of the upper lip 46, form a frame guide 50 above the mouth 48 along most of its length. The guide 50 provides an enlarged area of contact between the culvert wall and the frame to make it easier for the frame to follow the culvert wall regardless of its shape. The bottom surface of each plate SOa, SOb extends to slightly below the edge 47 of the upper lip to form a longitudinal channel 52 (best viewed in figs.2 and 5) for the back cutting wheels which extend across the mouth and beyond the radial extent of the culvert's wall. The guide 50 also prevents debris, such as soil from the ground above the pipe, from falling past the cutting apparatus into the inner cavity of the pipe being cut open.
15 The cutting wheels 70, which are individually designated by reference numerals 70a to 70e, are rotatably mounted along the lower lip 44 by suitable means, such as the nut and bolt/axle arrangement 74 which operationally engages the wheel's bore 76, shown in figs.6-8. The wheels 70a-70e are arranged so that they are stepped in stages upwardly toward the upper lip 46, and more particularly toward the channel 52 of the 2o body 40, progressively from the mouth's front opening toward its back throat. In the preferred embodiment the outer perimeter 72 of the first cutting wheel 70a (which first engages the wall of the existing culvert wall as it enters the mouth) extends the least distance from the lower lip 44 into the mouth 48. In contrast, the outer perimeter of the last, or fifth, cutting wheel 70e extends the furthest from the lower lip 44 and across the 2s mouth 48 into the channel 52 of the upper lip, in close proximity to the base of the channel. In the embodiment shown, the first three wheels 70a-70c are of the same size, but the bolt holes 62 (see fig.2a) are spaced progressively closer to the mouth 48 to bring the perimeter of the cutting wheels 70a-70c progressively closer to the upper lip. The fourth cutting wheel 70d is of greater diameter than wheels 70a-70c so that its outer perimeter is yet closer to the upper lip than wheel 70c. Finally, the fifth cutting wheel 70e has a greater diameter than wheel 70d to bring its perimeter closest to the frame's upper lip. It will be understood that other configurations of wheel sizes and bolt hole locations are possible to achieve a progressive cut of the pipe wall within the mouth 48.
As the cutting apparatus is drawn into contact with the culvert wall, the cutting wheels apply a progressively greater pressure on the wall to cut therethrough.
By the time that the last wheel 70e engages the cut being formed in the wall, the wall should be at least nearly or fully severed. As a "fail-safe" precaution, an inclined elongate opening 54 extends from the back of the mouth 48 behind the last cutting wheel 70e to present a hardened, sharpened lower edge, termed a "ripper" 56. The ripper ensures that any uncut culvert wall that might pass the last wheel 70e will be severed as the cutting tool is pulled through the existing culvert.
1s The leading edge 58 of the upper lip 46 has an upward pitch from the front to the back of the frame 40, with a steeper nose portion 58a and a more gradually sloped spinal portion 58b. The leading edge is hardened and sharpened for shearing any exterior obstructions that are encountered along the culvert's wall, such as exterior bolts or banding for joining sections of the culvert, and for pushing aside the ground through 2o which the frame 40 travels. An elongate hole 60 further along the spine toward the back of the frame forms a handle for a user to grip and lift the tool by hand.
As shown in fig.9, more than one cutting tool may be mounted on an existing culvert to provide a corresponding number of longitudinal cuts therethrough.
The number of cutting tools used will be determined by prior inspection and site conditions, such as 2s the condition of the soil and of the culvert.
An example of the typical operation of the present invention may now be illustrated. Once one end of a culvert is located and, if need be, excavated to expose the inlet, the cutting tool's mouth is slid onto the culvert wall and is pushed on as far as it will go until the cutting wheels resist further movement. The pull string 20 should already be passed through to the other end of the culvert where the cutting is to finish, and the nose 42 of the tool should be attached to a coupling plate 24 and traveling link 26 of s suitable size for the diameter of culvert to be cut. The number of cutting tools to be used is determined based on the earlier mentioned criteria. The expanding head 30 is connected to the end of the pull string just behind the cutting tool, and the new culvert is in turn connected to the expanding head via the collar 32. Force is then exerted on the far end of the pull string to draw the cutting tool longitudinally further onto the culvert wall.
1o The cutting wheels 70 engage the wall with greater force and progressively push the wall toward the upper lip 46, and in doing so the wheels form a cut through the wall, thereby severing the culvert. The expanding head then spreads the severed culvert and draws in the new culvert as is known in the art. As the cutting tool travels along the culvert, the lower lip 44 remains inside the culvert while the upper lip 46 remains outside the culvert.
1s Hence, the frame's leading edge 58 pushes aside the ground and severs any external pipe obstructions that are encountered, such as external bolts.
An important advantage of the cutting tool is its ability to cut through the culvert wall regardless of the culvert's structural integrity. The cutting tool 10 does not rely on structural support from other portions of the culvert to counteract cutting forces. Rather, 2o the upward forces of the cutting wheels 70 on the culvert wall are counteracted, or resisted, by the opposed upper lip 44 of the frame. Hence, all of the required cutting forces are offset "internally" within the cutting tool itself.
Another advantage of the present invention is the ability to use the same cutting tool for various sizes of culverts. As long as the thickness of the culvert wall can be 2s accommodated within the mouth 48 of the cutting tool, a user need only provide a suitably sized coupling plate 24 and/or travelling link 26 for the choosen culvert. Hence, a user is able to avoid the needless cost of stocking various sizes of cutters and of transporting several sizes of cutters to a work site.
Yet another advantage is that the leading edge 58 is adapted to effectively cut through external culvert obstructions which traditionally have been problematic for s conventional tools.
A further advantage is the ability to use more than one cutting tool during a single pass through an existing culvert to provide the desired number of longitudinal cuts.
Hence the apparatus is easily and quickly adapted at a work site to the size and integrity the particular pipe, as well as the existing soil conditions.
1o The above description is intended in an illustrative rather than a restrictive sense, and variations to the specific configurations described may be apparent to skilled persons in adapting the present invention to other specific applications. Such variations are intended to form part of the present invention insofar as they are within the spirit and scope of the claims below.
Claims
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002354737A CA2354737A1 (en) | 2001-08-02 | 2001-08-02 | Method and apparatus for cutting and splitting pipe |
| CA002364666A CA2364666A1 (en) | 2001-08-02 | 2001-12-07 | Improved method and apparatus for cutting and splitting pipe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002354737A CA2354737A1 (en) | 2001-08-02 | 2001-08-02 | Method and apparatus for cutting and splitting pipe |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2354737A1 true CA2354737A1 (en) | 2003-02-02 |
Family
ID=4169670
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002354737A Abandoned CA2354737A1 (en) | 2001-08-02 | 2001-08-02 | Method and apparatus for cutting and splitting pipe |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2354737A1 (en) |
-
2001
- 2001-08-02 CA CA002354737A patent/CA2354737A1/en not_active Abandoned
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| USRE35542E (en) | Pipe bursting and replacement method | |
| US5098225A (en) | Cutting/expanding tool | |
| US5306101A (en) | Cutting/expanding tool | |
| US5171106A (en) | Cutting/expanding tool | |
| US6109832A (en) | Ram burster and method for installing tubular casing underground | |
| EP0870151B1 (en) | Apparatus for removal of utility line and replacement with polyolefin pipe | |
| CA1216276A (en) | Apparatus and method for extracting horizontal underground pipe | |
| US5282696A (en) | Pneumatic ram pipe replacement | |
| US5507597A (en) | Underground pipe replacement method | |
| US5687805A (en) | Back reamer apparatus | |
| US20020081156A1 (en) | Tool for replacement of underground plastic pipe | |
| CA2354737A1 (en) | Method and apparatus for cutting and splitting pipe | |
| CA2364666A1 (en) | Improved method and apparatus for cutting and splitting pipe | |
| US20030084764A1 (en) | Method and apparatus for replacement of ductile pipe | |
| JPH036396B2 (en) | ||
| US6655874B2 (en) | Method and apparatus for slitting flexible pipe in an underground bore | |
| CN214466562U (en) | Pipeline replacement device is widened in broken of non-excavation | |
| JP2002303379A (en) | Replacing method without open-cut of buried pipe and pipe dividing tool | |
| CA2900182A1 (en) | Method and apparatus for culvert crushing | |
| JPH0255676B2 (en) | ||
| KR100323386B1 (en) | An apparatus for Pipe cutting and exchanging | |
| CA2310529C (en) | Method and apparatus for installing culverts | |
| JPH0432197B2 (en) | ||
| JPH10184995A (en) | Removing device for decrepit pipe | |
| JP2002303097A (en) | Non open-cut exchange method of buried pipe, and pipe- splitting tool |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 20031105 |