Pulley bursting head

Abstract

Disclosed is a bursting head device or tool whose interior accommodates a pulley system competent to engage a pulling cable. The pulley can comprise a wheel on an axle or shaft designed to support movement and change of direction of the pulling cable and can include a groove or channel around its circumference to locate the cable. The improved bursting head device is competent to increase the effective pulling force or capacity of a bursting head pulling machine and can increase the machine's effective range of replacement pipe diameters.

Claims

1. A bursting head device dimensioned to burst a pipe when pulled through said pipe by a cable, comprising: a cone body having an anterior and posterior end, an interior cavity and an anterior aperture through which said cable can enter and exit said cavity, and a pulley wheel located in said cone body interior cavity and comprising a groove around the external circumference of said wheel dimensioned to locate said cable, such that when said cable is located about said pulley wheel, one free end of said cable is attached to an external anchor point, the other end of said cable is attached to a pulling means, and said pulling means is engaged, said pulley wheel rotates about a central shaft and said bursting head device is pulled towards said pulling means.

Description

DESCRIPTION OF THE DRAWINGS

(1) The foregoing aspects and many of the attendant advantages of this disclosure will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

(2) FIG. 1 illustrates a prior art bursting head;

(3) FIG. 2 illustrates a bursting head according to one embodiment of the instant disclosure;

(4) FIG. 3 illustrates a pulley bursting head mechanism according to one embodiment of the instant disclosure;

(5) FIG. 4 illustrates a pulley bursting head mechanism according to one embodiment of the instant disclosure;

(6) FIG. 5 illustrates a pulley bursting head mechanism according to one embodiment of the instant disclosure;

(7) FIG. 6 illustrates a pulley bursting head mechanism according to one embodiment of the instant disclosure;

(8) FIG. 7 illustrates a pulley bursting head according to one embodiment of the instant disclosure, and

(9) FIG. 8 illustrates a pulley bursting head according to one embodiment of the instant disclosure.

DETAILED DESCRIPTION

(10) Embodiments of the present disclosure provide devices, tools, components, mechanisms and methods of use directed to improved means for bursting pipe underground, particularly degraded or under-capacity pipe.

(11) The pulley bursting head of the present disclosure provides a novel solution for increasing the pipe bursting capacity of a given pipe bursting pulling machine. The device allows an operator to increase the pipe bursting diameter range of her/his pulling machine without requiring larger cable diameter or substantive modification to the pulling machine's pulling force capabilities.

(12) Referring to FIG. 1, a representative bursting head tool or device of the prior art is shown. In the figure, bursting head tool 10 has a cone body 12, having a substantially conical shape with a front or “nose end” 22 of a smaller diameter than the diameter of back end 24. The cone body optionally can include one or more cutting blades 14 on its outer surface to support fracturing the existing pipe through which bursting head device 10 is being pulled through. The back end of bursting head 10 can include a linkage 16 connecting device 10 to replacement pipe being pulled through together with bursting head 10. Typically the replacement pipe is coupled to bursting head 10 via a universal duct puller 18 or similar structure. The free end of a pulling cable 20 typically is attached to the front end of bursting head 10 in the devices of the art, either by an external linkage or, as in FIG. 1, by means of an internal clamping mechanism that secures the free end of cable 20 to the device and cable 20 extends out from a single nose end aperture 26 of cone body 12.

(13) Referring to FIGS. 2-8, bursting head device 10 can include a cone body 12 that houses an internal pulley mechanism competent to locate cable 20 in a channel or groove 32 and reverse cable 20's direction. Nose end 22 of cone body 12 can include two apertures 28 to accommodate cable 20 entering and exiting cone body 12. Highlighted in FIGS. 2, 3 and 8 in particular, apertures 28 can comprise part of a front cap 50 that attaches to cone body 12. As with bursting head devices in the art, cone body 12 also can include means for accommodating one or more splitting blades on the cone body 12 outer surface. FIG. 2 illustrates a groove 15 into which a splitting blade can be fitted, if desired.

(14) FIGS. 3-5 illustrate one representative useful pulley mechanism that may be used to advantage. In the figures, pulley wheel 30 includes a groove or channel 32 that accommodates and locates cable 20 as the cable travels around wheel 30. Wheel 30 is on an axle or shaft 34 that supports movement and change of cable direction as wheel 30 rotates about shaft 34, and cable 20 is the pulley system or pulley mechanism drive element. If desired, wheel 30 also can include one or more weight-reducing gaps, holes or cut-outs 38.

(15) In the figures axle 34 and wheel 30 is held between pulley blocks 36. In the figures blocks 36 connect the pulley mechanism and attached cone body 12 to linkage means 16 that couple bursting head device 10 to the replacement pipe.

(16) In the embodiment illustrated in the figures, pulley wheel 30 in placed in a hollow interior of cone body 12, and can include any useful means for securing the pulley system or mechanism to the cone body. Exemplary, illustrative components include cable channel extender 40, configured with a channel 32 to accommodate, locate and guide cable 20 across the distance between front cap 50 and pulley wheel 30. A filler component 42 also can be provided that at least partially fills the available space of the cone body interior not occupied by the pulley mechanism.

(17) In FIGS. 5-8, filler component 42 comprises two ribbed or strut-like structures that are attached by standard means to opposing sides of pulley wheel 30 and extender 40 such that the composite structure has an overall conical shape dimensioned to substantially mirror and fill the conical interior cavity of cone body 12. In the figures an axle housing 44 encases axle 34 and provides means for connecting wheel 30 and block 36 to filler component 42 by filler attachment means 46. Similarly, filler component 42 can be attached to extender 40 by any standard means including, for example, bolting means 48.

(18) It will be appreciated by those having skill in the art that the embodiments illustrated here are exemplary and that, provided with the instant disclosure, a range of means for constructing a bursting head with an internal cable pulley system or mechanism now can be fabricated by one of ordinary skill in the art without undue experimentation. For example, a bursting head cone body could be machined to create a pocket into which a pulley wheel could be inserted and the axle shaft attached to the cone body interior itself, or to a block that attaches to the cone body interior or directly to linkage 16.

(19) In operation, the pulling machine is located at the extraction or receiving point, preferably positioned so cable pulling action is in alignment with the existing pipe cavity. A cable free end is provided through the pipe cavity to the insertion point where the bursting head device and attached replacement pipe are located, and the free end provided through the cone body nose end opening, around the pulley wheel, back out the nose end, and provided back through the pipe cavity to the extraction or receiving point. Preferably, means are provided on the pulling machine or, more preferably on a crib in which the machine sits, or at some other location at the receiving point, for anchoring the cable free end. The anchoring means can include a cable clamping means analogous to the cable gripping means used by the pulling machine, including means that provide a modulatable gripping and release means common to pulling machines. As the pulling machine pull the attached cable towards the receiving point, the bursting head and attached replacement pipe are pulled forward through the pipe.

(20) The pulley bursting head allows the machine to double its effective pulling power. In the case of a piston-driven pulling machine, each piston stroke now moves half the cable distance, which can effectively double the power. Pulling machines that operate well in the 30-40 ton pulling force range generally have an operational pipe diameter cap of about 6-inches. Using the pulley bursting head device, the effective pulling capacity of the machine now can be doubled, in the range of about 60-80 tons, which can expand operational pipe diameter cap to include 8, 10 and 12-inch diameter pipe.

(21) Embodiments of this disclosure may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the disclosure being indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the disclosure.