JPS61180082A - Piping breaking tool - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to pipe bursting tools, and in particular, but not exclusively, to tools for bursting gas, water or sewer pipes.

1 consisting of a body that is pulled into a pipe by a cable and has an impact mechanism that operates so that the pipe receives repeated impacts;
Two forms of tools are available in British Patent Application Publication No. 2.092.7 (
10) It has been described and used in No.A. The tool has a relatively narrow blade whose front end is pivotally connected to the body of the tool and which can be displaced obliquely outwardly and inwardly by a hydraulic cylinder. The blade is adapted to cut the pipe joint by outward displacement.

It has been found that such tools are not effective in rupturing tubes of construction and in other types of ground. A similar type of tool was proposed in British Patent Application Publication No. 2.139.938A, in which a pneumatic hammer strikes a rotating blade.

Other forms of tooling used to correct misaligned or reduced cross-sections in sewer pipes to restore the original internal diameter were proposed in British Patent Application Publication No. 2.122.299A.

Side loads acting on the displaceable elements and the wedges displacing these elements are transmitted to the piston rod of the hydraulic cylinder displacing the wedges. Therefore, the cylinder assembly is subjected to bending loads that impair the life or proper operation of the tool.

It is an object of the present invention to provide a tube bursting tool that reduces or eliminates the disadvantages of previously used or proposed tools.

A tube bursting tool according to the present invention includes an elongated body and first and second devices for attaching the body to a pulling device and a bore liner, respectively, the body having a profile that tapers toward its forward end and an outer wall portion lengthwise divided into a first portion and a second portion, the wedge being movable longitudinally of the body between the first portion and the second portion by a hydraulic cylinder; sliding of the wedge against a support surface associated with the cylinder and a support surface arranged so as not to subject the cylinder to lateral and bending loads acting on the body causes the first portion to move laterally of the body; It is a feature.

Preferably, said second portion extends forwardly from an annular portion of the body wall.

Preferably, each of said first and second portions extends 180° in the circumferential direction.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings.

The bursting tool shown in the drawing has the following main components: three parts;
namely, a body 10 consisting of a cylindrical front part 12, a hollow part 14 having a frustoconical wall and made up of a first part 16 and a second part 18, and a cylindrical rear part 20; 16 and 18; and a hydraulic cylinder 24 having a piston rod 26 housed in the rear part 20 and connected to the wedge 22.

The bursting tool is pulled through the tube to be ruptured by a pulling device, such as a self-advancing mechanism that can advance inside the tube, or by a pulling device in the form of a cable connected to a winch. A cable or other device is attached to a clevis 28 secured to the tip of the front section 12.

The bursting tool forms an enlarged cavity in the ground and draws into the cavity a polyethylene or similar tubular liner 30 that extends over the rear section 20 and is secured to the rear section 20 by clamps 32. As a modification, the liner may be made of polyvinyl chloride tubular lengths, and these lengths may be made of e.g.
The interconnection may be by interengaging socket end structures and cables threaded through the elongate, or by other means. The liner assembly is secured to the rupture tool by a cable or other device.

The front section 12 and the middle section 14 are of welded construction made of steel. Alternatively, the sections may be of cast construction, the front section 12 being a hollow cylinder that receives the front end of the wedge 22 as it is advanced beyond the small diameter end of the intermediate section 14. The front part 12 is the middle part 1
It has an opening at the rear end of its wall for receiving the front end of the first portion 16 of No. 4 (FIG. 4). On each side of this opening, the rear portion of the front section 12 supports a shroud 40. Two shrouds 40 cover the front edge 42 of the wall 44 of the first portion 14 .

The wall 44 is partially frustoconical and defines 180° of the circumference of the intermediate section 14 between the small diameter end of the intermediate section 14 and the rear end 46 of the wall 44 . The wall 44 is supported by an elongated inner support 48 which is connected to the wedge 2.
A member 48 is movably housed between the shrouds 40 and has an inner support pad 50 that slidably engages an upper support pad 52 of the 2.

The underside of the wedge 22 has a support pad 54 that slidably engages a support pad 56 supported by an opposing support 58 . The support 58 is the second
It is fixed to part 18.

Support 58 is positioned between two side plates 60 that extend straight through intermediate section 14 and front section 12 and accommodate wedge 22 therebetween.

The outer edges of the support pads 50, 52 are slidably engaged with opposing grooves of a pair of plates 62 fixed to both sides of the member 48, respectively.

Similarly, the pads 54 and 56 are received in opposing grooves in a pair of plates 64 fixed to both sides of the wedge 22, respectively. As such, as can be seen in FIG. 1, when wedge 22 is retracted to the left, first portion 16 is retracted inwardly.

Member 48 supports short outer ribs 66 as extensions of ribs 68 formed on the outside of wall 44 .

The tips of the ribs 66 do not protrude beyond the outer surface of the front portion 12 even in the outer position of the portion 16 shown in FIG. part 18
has an outer rib 70 diametrically opposed to rib 68 . These ribs are optional.

The first portion 16 has an extension strip 72 welded to its outer surface.
on each side edge (Fig. 2). The inner surface of the strip 72 slides over the flat edge surface of the second lower portion. middle part 1
4 has an annular wall portion 76 that is generally frustoconical. A second portion 18 of intermediate portion 14 is secured to and extends forwardly from the leading edge of wall portion 76. The front edge of wall portion 76 is secured to a circular plate 78 having a generally cross-shaped opening. The rear section 20 is a steel cylinder having a forward outer flange 80 secured to the plate 78 with bolts. 'The rear end of the side plate 60 is the plate 7
The receiver is inserted into the opening 8 and is fixed to this plate.

The side plates 60 are supported by transverse plates 90,92,94 fixed to these and to the part 76 or the second part. The front end of the side plate 60 is fixed to the inner surface of the front portion 12.

Cylinder 24 has a connection, such as 100, by which liquid is conveyed to and from a power bag (not shown) via a conduit extending through liner 30. When the bursting tool is pulled by the self-propelled device, further connections such as 102 direct fluid to conduits 104, 106 passing through the body 10 and exiting from holes (not shown) in the front end of the front section 12. It can then be conveyed to the cylinder of the pulling device.

When the bursting tool is pulled by the pulling table (as is preferred), only a hydraulic connection with the cylinder is required. In that case, the front part is preferably modified from that shown to provide a tapered lug and a D-shaped shackle is connected to this tapered lug by means of a pin.

The operation will be explained below.

Assuming that the bursting tool is pulled by a cable and winch, the cable is fed into a section of existing buried pipe whose end has been exposed by excavation.

In the case of gas distribution systems, the pipes are made of cast iron, ductile iron or asbestos-based materials. Other pipes, such as water pipes or sewer pipes, are made of cast iron, clay or vitreous ceramic materials. The bursting tool is applicable to bursting all kinds of such pipes. The winch is preferably a hydraulically driven winch housed in a cut-out at the end of the tube, with a cable extending in a straight line from the tube to the winch barrel.

One end of a relatively thin liner 30, in the case of a polyethylene liner, is fitted onto the rear section 20 and attached to this section by a clamp 32. Attach the cable to body 10,
Activate the winch to pull the bursting tool into engagement with the end of the tube. At this stage, the first part 16 can be retracted. Cylinder 24 is then actuated to advance wedge 22, thereby pushing first portion 16 outwardly. Typically, up to 36 tons of force is exerted on the tube and the surrounding ground by the first section 16 and second section 18 using hydraulic pressures of up to 207 bar (300 (10) bs/aJ), for example. to occur. The outward movement of section 16 ruptures the tube and partially enlarges the underground cavity.

The portion 16 is then retracted and the rupturing tool is advanced as far as possible by the load applied by the advancing mechanism, e.g. a cable.

In doing so, portion 16.18 and frustoconical wall 76
makes the enlarged part of the void just mentioned even larger. Thus, the fragments of the previously broken pipe are forced outward into the surrounding soil.

A typical cast iron pipe is, for example, 150 mm (6 inches).
The diameter of the fully expanded cavity formed by the bursting tool is 240 fl (9.5 inches) to receive the liner 30 having an outside diameter of 202 m (8 inches). The same bursting tool is also preferably designed to rupture tubes having an internal diameter of 127 mm (5 inches), 178 mm (Twift) or 203 mm (8.5 inches).
can be used. Bursting tools made in different sizes are, for example, 102 m (4 inches) or 127 m (
Burst a steel or tube with an internal diameter of 5 inches).

If the winch can be set to operate at constant pressure, the winch may be effectively self-regulating so that relatively little effort is required by the operator to control it. The bursting tool advances while the resistance is low, ie after retraction of the first part 16 following the bursting action. Cable tension keeps the rupturing tool engaged with the unruptured tube. By repeating the above operations, the first portion 16 is successively advanced and retracted, and the bursting tool is progressively advanced by the tension of the cable as it ruptures and expands the tube.

The winch must be capable of providing sufficient cable tension to overcome the frictional resistance experienced by the bursting tool and the liner connected to the bursting tool.

By virtue of the fact that portions 16 and 18 correspond to substantially the entirety of the frustoconical intermediate portion 14 and that the first portion 16 is entirely advanced outwardly relative to the portion 18, each portion 16, including both ends, The action of the two parts 16.18 on the rupture pipe and the ground adjacent to it is such that these parts are relatively separated by the wedge. When separated, it is more efficient in rupturing the tube and expanding the cavity than the action of known types of hinged members or tapered bodies pushed into the cavity.

First section 16 is shown in the fully advanced position in FIG. It is the same as the diameter. This, and the relatively small diameter of the rear section 20, significantly relieves frictional forces from the liner 30 during operation.

After the liner 30 is pulled into the rupture tube, the rupture tool is released from the liner 30. The new tube, typically made of a plastic material such as polyethylene, is drawn through a liner 30 that protects the outer surface of the tube from scratches and scratches.

Alternatively, the liner and the new tube placed therein are both attached to the bursting tool and pulled together into the expansion cavity. As yet another alternative, typically, for example, in replacing a sewer pipe, only the new pipe is installed in the tool and pulled into the cavity without the use of a separate liner. The new tube itself then constitutes the only liner,
In this specification, the term "liner" means any liner through which the tube itself is new.

The body 10 has a strong structure, and the counter support 5
8, and a support pad is attached to this support. The cylinder 24 is cantilevered to the plate 78 at one end. Bending loads and side loads acting on the body are supported by and reacted within the rigid body. For example, the first portion 16 and the second portion
Side loads acting on portion 18 are counteracted via wedge 22. Thus, the supporting surface provided by pad 56 for wedge 22 keeps cylinder 24 free from side loads and bending loads acting on the body.

In a variant, there is one or more, for example two, first parts;
Each spans 180° and overlaps at the side edges by extension strips. The wedge slides between the two first parts. In such a configuration, the second portion 18 can be omitted.

In such a variation, the body has a spine member rigidly attached to portion 76. This spine member corresponds to a counter support 58 into which the wedge slidingly engages at its support pad. This spine member thus eliminates side loads and bending loads acting on the body from being imposed on the cylinder assembly.

In the retracted position of the first portion 16 shown in FIG.
is a frusto-conical extension of the wall of section 76. Inside the first section 16, a bulkhead is formed by a transverse plate adjacent the rear end of the wall 44 and near the section 76, so that when advancing the first section, the wall 44 and the section 76 There is no open gap between them.

The first portion 16, the second portion IB, the front portion 12 and the wall portion 76 create a substantially closed housing complementary to the cylinder 24. The exposed portions of the wedge 22 and piston rod 26 are exposed regardless of whether the first portion is advanced or retracted.
During operation, it is always covered by the housing.

In yet another variant (not shown) (i) the frusto-conical wall 76 is replaced by a cylindrical wall, the diameter of the rear end of the portion 16.18 in the fully closed position being equal to the diameter of the cylindrical wall; For example, 240 cranes. The length of the wall part is arbitrarily increased compared to the length shown in the drawing.

(ii) instead of the intermediate section 14 being transversely circular throughout in the closed position of the section 16.18;
It changes from a circular section at its rear end to an oval section at its front end. In this case, the minor axis of the ellipse is vertical in the cross-sectional view corresponding to FIG.

The diameter of the cylindrical front section is preferably equal to the long axis of the ellipse at the front end of the intermediate section, so that the front section covers the front end of the blade 68.70.

The shroud 40 can be omitted.

Either a flat wall section or a fairing closes the gap between the rear end of the front section and the oval wall of the intermediate section.

This variant increases the effectiveness of the separation movement of the sections 16, 18 when rupturing the tube or enlarging the cavity. The cross-section of the intermediate part changes from an elliptical shape in the relative closed position of the parts 16,18 to a substantially circular shape in the relative separated position of these parts as the wedge advances.

[Brief explanation of the drawing]

1A and 1B are longitudinal cross-sectional views of the tube bursting tool; FIG. 2 is a vertical cross-sectional view along the line II-If of FIG. 1;
3 is a plan view of a part of the body of the tool shown in FIGS. 1 and 2; FIG. 4 is a vertical sectional view taken along line IV-fV in FIG. 3. 10...Body, 12 ...Cylindrical front part, 14...
- Middle part, 16... First part, 18... Second part, 20... Cylindrical rear part, 22... Wedge, 24
... Hydraulic cylinder, 26 ... Piston rod, 30
... liner, 40 ... shroud, 48 ... support,
52.54.56...Support pad, 58...Counter support, 66.68.70...Rep.

Claims (12)

[Claims] (1) an elongate body and first and second devices for attaching the body to a pulling device and a liner, respectively; the body has a profile that tapers toward a forward end thereof; an outer wall section longitudinally divided into two sections, the wedge being movable along the length of the body between the first section and the second section by means of a hydraulic cylinder, a support surface associated with the first section; A pipe rupturing tool characterized in that movement of the wedge relative to a support surface arranged to spare the cylinder from side and bending loads acting on the body causes the first portion to move laterally of the body. 2. The tool of claim 1, wherein the second portion extends forwardly from a frusto-conical annular portion of the body wall. (3) The tool according to claim 1 or 2, wherein each of the first portion and the second portion extends 180° in the circumferential direction. (4) The longitudinal edges of one of the first and second portions are overlapped at the respective longitudinal edge extensions of the other of these portions.
The tool described in any one of items 1) to 3. (5) The first portion and the second portion support longitudinal outer ribs extending longitudinally and diametrically opposed to each other. Tools described in any of Section 4. (6) The tool according to claim 5, wherein the ribs of the first portion extend forward beyond the ribs of the second portion. (7) The front end of the rib of the first part does not project beyond the outer surface of the front part even when the first part assumes its outer position. or a tool as described in paragraph (6). (8) The tool according to any one of claims (1) to (7), wherein the wedge is longer than the first portion. 9. The tool of claim 8, wherein the wedge extends beyond the front end of the first portion at all positions thereof. (10) Any one of claims (1) to (9), wherein the second device comprises a hollow rear portion of a body that houses the hydraulic cylinder and into which the front end of the liner is fitted. Tools listed in section. (11) A tool according to any one of claims (1) to (10), characterized in that the second portion is immovable with respect to the support surface of the body. (12) The first part and the second part are both movable relative to the support surface of the body. Tools listed.