Abstract:
A pipe extraction tool grips the inside of a pipe or other such conduit to facilitate removal of a pipe which can not otherwise be removed. The extraction tool uses expandable jaws to grip the inside of the pipe.

Description:
RELATED APPLICATIONS 
       [0001]    The present application claims the benefit of U.S. Provisional Application Ser. No. 60/867,063, filed Nov. 22, 2006, which is expressly incorporated herein in its entirety, and U.S. Provisional Application Ser. No. 60/887,068, filed Jan. 29, 2007, which is expressly incorporated herein in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. The Field of the Invention 
         [0003]    The present invention relates to a pipe extraction tool. More specifically, the present invention relates to a tool for extracting pipe or the like by gripping the inside of the pipe to facilitate removal thereof. 
         [0004]    2. State of the Art 
         [0005]    Pipes are used in many situations, such as irrigation pipes, water supply lines, gas pipes, etc. Commonly, pipes are used which are threaded, and which are screwed into a fitting such as an elbow or tee to connect the pipe together. Often, a system of pipe includes a permanent system of pipe to distribute fluids to desired locations, and threaded inserts at these locations to allow the connection of a valve, sprinkler head, etc. to the pipe. The distribution pipe is often soldered or glued together, and is difficult to repair. The sprinklers heads, valves, etc. are often connected by a short piece of pipe such as a riser or standoff, which is typically threaded into the distribution pipe. 
         [0006]    It is not uncommon for a pipe to break. For example, sprinkler/irrigation pipes are often broken when a lawn mower, tractor, or other vehicle accidentally drives over a sprinkler head. In such a situation, the standoff or riser is often broken at or near the connection to the distribution pipe. It is often difficult to remove the broken pipe, as it often breaks underground. Thus, it may be necessary to dig a hole to expose the connection between the riser pipe and the distribution pipe and remove and replace the riser pipe. It is often difficult to remove the riser pipe even after exposing the connection, as the riser may break off at the threaded end of the riser, as the threaded section is weaker than the rest of the pipe. Thus, there may be very little if any of the riser pipe extending from the distribution pipe. 
         [0007]    There is thus a need for a pipe extraction tool which allows for the removal of pipe or the like when little or none of the pipe exterior is exposed. There is a need for a pipe extraction tool which allows for removal of pipes without requiring a person to dig up or otherwise expose the pipe. 
       SUMMARY OF THE INVENTION 
       [0008]    It is an object of the present invention to provide an improved pipe extraction tool. 
         [0009]    According to one aspect of the invention, a pipe extraction tool is provided with a head which is inserted into a pipe, and with jaws which grip the inside of the pipe. The extraction tool may use a tapered wedge which is moved to expand the jaws into the pipe. Such an extraction tool provides a high gripping force and may be used to remove large pipe, or pipe which is rusted or otherwise stuck. 
         [0010]    The extraction tool may also be provided with a stop to automatically position the tool at a proper depth in the pipe, and may include a biasing element to bias the jaws to a non-gripping position. Such features make the extraction tool easier to use, especially where the pipe is underground or otherwise inaccessible. 
         [0011]    These and other aspects of the present invention are realized in a pipe extraction tool as shown and described in the following figure and related description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0012]    Various embodiments of the present invention are shown and described in reference to the numbered drawings wherein: 
           [0013]      FIG. 1A  shows a perspective view of the pipe extraction tool of the present invention; 
           [0014]      FIG. 1B  shows a partial perspective view of the tool of  FIG. 1A  having a different locking nut; 
           [0015]      FIG. 2  shows a top view of the extraction tool of  FIG. 1A ; 
           [0016]      FIG. 3  shows a side view of the wrench body of  FIG. 1A ; 
           [0017]      FIG. 4  shows a top view of the wrench body of  FIG. 3 ; 
           [0018]      FIG. 5  shows a bottom view of the wrench cap of  FIG. 1A ; 
           [0019]      FIG. 6  shows a cross-sectional view of the wrench cap of  FIG. 5 ; 
           [0020]      FIG. 7  shows a side view of a wrench jaw of  FIG. 1A ; 
           [0021]      FIG. 8  shows an end view of the wrench jaw of  FIG. 7 ; 
           [0022]      FIG. 9  shows a cross-sectional view of the wedge of  FIG. 1A ; 
           [0023]      FIG. 10  shows a side view of the screw of  FIG. 1A ; 
           [0024]      FIG. 11  shows a top view of the screw nut of  FIG. 1A ; 
           [0025]      FIG. 12  shows a partial cut-away view of the wrench of  FIG. 1A ; 
           [0026]      FIG. 13  shows a perspective view of an alternate embodiment of wrench jaws and wedge according to the present invention; 
           [0027]      FIG. 14  shows another perspective view of the jaws and wedge of  FIG. 13 ; and 
           [0028]      FIG. 15  shows a perspective view of a wrench having the jaws and wedge of  FIG. 13 . 
       
    
    
       [0029]    It will be appreciated that the drawings are illustrative and not limiting of the scope of the invention which is defined by the appended claims. The embodiments shown accomplish various aspects and objects of the invention. It is appreciated that it is not possible to clearly show each element and aspect of the invention in a single figure, and as such, multiple figures are presented to separately illustrate the various details of the invention in greater clarity. 
       DETAILED DESCRIPTION  
       [0030]    The invention and accompanying drawings will now be discussed in reference to the numerals provided therein so as to enable one skilled in the art to practice the present invention. The drawings and descriptions are exemplary of various aspects of the invention and are not intended to narrow the scope of the appended claims. 
         [0031]      FIG. 1A  shows a perspective view of the pipe extraction tool of the present invention. The extraction tool  10  includes a wrench head  14 , stem  18 , and handle  22 . The wrench head  14  engages the inside of a pipe or the like to remove the same. The stem  18  allows the wrench head  14  to reach a pipe which is underground or otherwise inaccessible, and the handle  22  allows a person to provide sufficient torque to remove a pipe. 
         [0032]    The extraction tool  10  shown is about 53 inches long. As discussed herein, example dimensions are provided for an extraction tool  10  capable of removing a pipe with about a 2.75 inch diameter. It is appreciated that the tool  10  may be made in different sizes to accommodate different sizes of pipe, and in different lengths as is desired. It may be desirable to make different lengths for different sizes of pipe. When removing a relatively large sprinkler standoff, for example, it may be easier to have a long extraction tool  10  which may be inserted into the ground to reach the pipe, and which may be used by one or two persons while standing to achieve greater force. For an extraction tool  10  for removing smaller pipe, it may be desirable to have an overall tool length of about 12 or 24 inches for ease of use. 
         [0033]    The wrench head  14  includes a wrench body  26  and a wrench cap  30 . The wrench body  26  has openings to receive a plurality of wrench jaws  34  which are expandable from the wrench body  26  to grip the inside of a pipe. The wrench jaws  34  are expanded outwardly by a wedge  38  and a draw bar or screw  42  and screw nut  46  which are used to pull the wedge upwardly within the wrench body  26 . The screw  42  passes through the stem  18  such that the wrench jaws  34  may be expanded to grip a pipe by using a screw nut  46  and screw nut handle  50  which are adjacent the handle  22 . An O-ring  54  may be used to bias the wrench jaws  34  into the wrench body  26  in a non-griping configuration. 
         [0034]      FIG. 1B  shows a partial perspective view of the tool  10  of  FIG. 1A . The tool  10  utilizes a screw nut  46 ′ with a handle  50 ; which is shaped like a wing nut. It will be appreciated that a variety of different shapes of screw nut  46  may be used. 
         [0035]      FIG. 2  shows a top view of the extraction tool  10  of  FIG. 1A . It can be better seen how the screw nut  46  and screw nut handle  50  are in a convenient position for use.  FIG. 2  also illustrates bolts  58  used to hold the wrench body  26  and wrench cap  30  together. 
         [0036]      FIG. 3  shows a side view of the wrench body of  FIG. 1A . The wrench body  26  has slots  62  for receiving the wrench jaws  34 . The wrench body  26  also has a groove  66  which receives the O-ring  54 , allowing the O-ring to sit beneath the surface of the wrench body  26 . For the size illustrated herein, the wrench body is about 2.75 inches in diameter. The slots  62  are about 0.38 inches wide and 1.06 inches deep. The groove  66  is about 0.22 inches wide and about 0.25 inches deep. 
         [0037]      FIG. 4  shows a top view of the wrench body of  FIG. 3 . It can be seen how the interior  70  of the wrench body  26  is hollow to receive the wrench jaws  34  and the wedge  38 . The wrench body also includes threaded holes  74  to facilitate attachment to the wrench cap  30 . For the size of tool shown herein, the interior  70  of the wrench body  26  has a diameter of about 1.75 inches. 
         [0038]      FIG. 5  shows a bottom view of the wrench cap  30  of  FIG. 1A , which is attached to the stem  18 . The wrench cap  30  includes an internal recess of about 1.75 inches in diameter and about 0.63 inches deep. A square hole  82  of about 0.6 inches is formed through the center of the wrench cap  30 . The screw  42  has an unthreaded square portion which passes through the hole  82 . The unthreaded portion of the screw  42  has a square shaft which, in combination with the square hole  82 , prevents rotation of the screw. Thus, the screw moves linearly through the hole  82 . Holes  86  are provided to allow for attachment to the wrench body  26 . 
         [0039]    The wrench cap  30  is about 3 inches in diameter, and is larger in diameter than the wrench body  26 . The wrench cap provides a stop, and does not allow the wrench  14  to be inserted too far into the pipe. If the wrench  14  is inserted too far into the pipe, it may pass through the pipe and not grip the pipe. Thus the present invention is particularly useful in removing sprinkler and irrigation risers which have broken off beneath the ground. 
         [0040]      FIG. 6  shows a cross-sectional view of the wrench cap of  FIG. 5 . The recess  78  and hole  82  of the wrench cap  30  may be better seen. It can also be seen how the holes  86  may be countersunk to receive the head of the bolts  58  ( FIG. 2 ) used to attach the wrench cap  30  and wrench body  26 . 
         [0041]      FIG. 7  shows a side view of a wrench jaw of  FIG. 1A . The wrench jaw  34  has a pipe engaging portion  90  about 1.05 inches long which extends through a slot  62  in wrench body  26  to grip a pipe. A notch  94  of about 0.2 inches width and depth may be formed therein for receiving the O-ring  54  of  FIG. 1A  such that the O-ring is not cut when the jaw  34  engages a pipe. 
         [0042]    The wrench jaw  34  has a first tab  98  which is received within the recess  78  of the wrench cap  30  and a second tab  102  which is disposed in the opening  70  in the wrench body  26 . The tabs  98 ,  102  aid in locating the jaw  34  and ensure that the jaw does not pass completely through the slot  62  in the wrench body  26 . An inclined surface  106 , formed at an angle of about 10 degrees for example, engages the wedge  38  and is used to push the jaw  34  outwardly against a pipe. 
         [0043]      FIG. 8  shows a top view of the wrench jaw of  FIG. 7 , illustrating how the pipe engaging portion  90  may be formed to have teeth  110  which aid in gripping a pipe. It will be appreciated that the engaging portion need not be formed in a concave shape as shown. If the engaging portion is simply cut flat, the corners thereof will still form relatively sharp edges which will engage the inside bore of a pipe to grip the pipe. The extraction tool  10  may be used for a variety of pipe materials, including plastic, iron, copper, etc. The present design uses three jaws  34  to aid in gripping the pipe and in automatically centering the extraction tool  10  in the pipe. 
         [0044]      FIG. 9  shows a cross-sectional view of the wedge of  FIG. 1A . The wedge  38  is a frusto-conical or cone shaped member having a tapered outer surface  118  of approximately the same angle as is formed in inclined surface  106  of the wrench jaws  34 . Thus, as the wedge  38  is drawn upwardly into the wrench body  26 , the jaws  34  are forced outwardly to grip a pipe. Preferably, the wrench jaws slide linearly to engage the pipe. Thus, the maximum engagement between the teeth  110  and the and the pipe is achieved. 
         [0045]    The wedge  38  has a hole  114  there through for receiving the screw  42 , and the wedge  38  is at a fixed position along the length of the screw  42 . Thus, drawing the screw  42  upwardly through the tool  10  also draws the wedge upwardly through the wrench body  26 , pushing the jaws  34  outwardly as surfaces  106  and  118  interact. 
         [0046]      FIG. 10  shows a side view of the screw of  FIG. 1A . The screw  42  includes a body  122 , preferably with a square cross section, and a cylindrical threaded end  126 . The threaded end  126  engages the screw nut  46 . The square body  122  passes through the square hole  82  in the wrench cap  30 , preventing rotation of the screw  42 . 
         [0047]      FIG. 11  shows a top view of the screw nut of  FIG. 1A . The screw nut  46  includes a threaded hole  130  which is threaded onto the threaded end  126  of the screw  42 . A handle  50  is used to rotate the screw nut  46 . 
         [0048]    Referring now to  FIG. 12  and also back to  FIG. 1A , the assembled extraction tool  10  is seen.  FIG. 12  shows a partial cut away view of the tool  10 , omitting the stem  18  for clarity. Following the discussion of the various pieces of the tool  10 , the construction and operation of the tool is more easily understood. The wrench top  30  is attached to the stem  18 , and the wrench body  26  is attached to the wrench top with the wrench jaws  34  extending outwardly through the slots  62  of the wrench body. The slots are indicated by a dashed outline in  FIG. 12 . The wedge  38  nests in the open interior  70  of the wrench body between the inclined surfaces  106  of the wrench jaws  34 . 
         [0049]    The screw  42  is attached to the wedge  38  and passes through the stem  18  and handle  22 . The screw nut  46  is attached to the threaded end  126  of the screw  42 . Tightening the screw nut  46  via handle  50  draws the screw  42  up through the stem  18  and wrench  14 , drawing the wedge  38  further into the open interior  70  of the wrench body  26  and extending the wrench jaws  34  outwardly to grip a pipe. Loosening the screw nut  46  allows the screw  42  and wedge  38  to slide back down through the stem and release the wrench jaws  34 , allowing the O-ring  54  to move the jaws back into the wrench body  26 .  FIG. 12  shows the jaws  34  (only one shown for clarity) in an extended position. It can be seen that the O-ring  54  is stretched away from the groove  66  in the wrench body  26  by the jaw  34 , and as such will exert a restoring force on the jaws  34  to pull them back into the wrench body  26  when the screw nut  46  is loosened. 
         [0050]    It is appreciated that the wedge  38  could be reversed so as to be wider on top and narrower on the bottom, and that the tapered surfaces  106  on the wrench jaws  34  could be similarly reversed such that the wedge is pushed downwardly to extend the jaws. For such a configuration, the screw  42  would likely rotate in the wrench and the stem  18  or handle  22  would contain a threaded portion such that as the screw  42  rotates, it is forced downwardly. The screw nut would be eliminated and the screw nut handle  50  would typically be attached directly to the screw  42  to rotate the screw. The configuration shows is, however, advantageous as it places the screw  42  in tension and does not present any buckling concerns when the wrench  14  is tightened. 
         [0051]    In use, a person would insert the wrench head  14  into a pipe, such as a broken pipe. If the pipe is broken underground, for example, the person may pull the broken off piece of the pipe out of the ground and insert the wrench head  14  into the resulting hole in the ground and into the remaining piece of pipe. When inserting the wrench head  14  into the pipe, the wrench top  30  provides a depth stop as it is larger diameter than the pipe bore, and the wrench body  26  is a smaller diameter than the pipe bore. It is appreciated that different sizes of extraction tools  10  may be made to accommodate different sizes of pipes, and may be made to accommodate a range of pipe sizes. 
         [0052]    Once the wrench head  14  is inserted into the pipe, the handle  50  is used to tighten the screw nut  46  and draw the screw  42  upwardly through the wrench to extend the jaws  34  and thereby grip the broken pipe. The broken pipe is then rotated out of the distribution pipe. 
         [0053]      FIG. 13  shows an alternate configuration of wrench jaws and wedge which may be easier to manufacture for smaller diameter pipes, such as one half inch, one inch, etc. The configuration shown in  FIGS. 1-12  may be more difficult to construct for smaller sizes. The wrench jaws  34 ′ are shaped roughly as half cylinders, and typically have ridges or teeth  110 ′ which grip the inside of a pipe riser and allow the riser to be extracted from a distribution pipe. 
         [0054]    The wrench jaws  34 ′ are formed with internal recesses  138  which define a tapering cavity  142  having a generally square cross section at any given point. The cavity  142  is smaller at one of the wrench jaws  34 ′ and larger at the other end of the wrench jaws and configured to receive wedge  38 ′ which also has a square shaped cross section. The wedge  38 ′ is inserted into the wrench jaws  34 ′. The cavity  142  and wedge  38 ′ have complementary shapes and tapers such that as the wedge  38 ′ is drawn inwardly through the wrench jaws  34 ′, the wrench jaws are pushed apart from each other and expanded into the interior bore of a pipe. The wedge  38 ′ may have a base portion  146  which prevents the wedge from being drawn too far into the wrench jaws  34 ′. 
         [0055]    The wrench jaws  34 ′ are formed with grooves  150  which receive a circular biasing member such as an O-ring, circular spring, spring wire, etc. The circular biasing member pulls the wrench jaws  34 ′ towards each other to release the jaws from the inside of the pipe when the wedge  38 ′ is not being drawn upwardly into the wrench jaws. The square cross section of the cavity  142  and the wedge  38 ′ prevent the wrench jaws  34 ′ from simply rotating around the wedge when using the tool to unscrew a broken riser pipe. While discussed herein as square, other cross section shapes can be used to prevent slipping. 
         [0056]      FIG. 14  shows another view of the wedge  38 ′ and wrench jaws  34 ′ of  FIG. 13  wherein the wedge has been drawn inwardly between the wrench jaws to force the wrench jaws apart so as to grip the inside of a pipe. It is appreciated how the expansion of the wrench jaws  34 ′ will be resisted by the biasing member (not shown) which is placed in grooves  150  such that the biasing member will pull the wrench jaws back together when the wedge  38 ′ is not drawn upwardly between the wrench jaws. 
         [0057]      FIG. 14  illustrates how the wedge  38 ′ may have a square hole formed therein for allowing a draw bar or screw (not shown, similar to screw  42 ) to pass therethrough. The draw bar or screw typically passes through the wedge  38 ′ and is used to pull the wrench jaws  34 ′ towards the wedge  38 ′. The wedge  38 ′ is attached to the stem of pipe extraction tool so as to rotate with the tool, causing the wrench jaws  34 ′ to rotate with the tool. 
         [0058]      FIG. 15  shows a pipe extraction tool  10 ′ having the wrench jaws  34 ′ and wedge  38 ′ of  FIG. 13 . The tool  10 ′ includes a handle  22  and stem  18  as have been discussed. base portion  146  of the wedge  38 ′ is attached to the stem  18  and prevents excessive upward motion of the wrench jaws  34 ′ when the wrench jaws are drawn upwardly by the draw bar  158  and base plate  154 . The action of the base plate  154  and draw bar  158  moving the wrench jaws  34 ′ upwardly causes expansion of the wrench jaws  34 ′ as has been discussed. The base portion  146  of the wedge  38 ′ may also form a depth stop to ensure that the tool is not inserted too far into a riser pipe. The draw bar  158  passes through the handle  22 , stem  18 , and wedge  38 ′, and is connected to the base plate  154  to allow pulling of the wrench jaws upwardly onto the wedge. A lever  162  is pivotably mounted to the handle  22  and is used to pull the draw bar  158  upwardly relative to the tool  10 ′ and thereby extend the wrench jaws  34 ′ to engage the bore of a pipe. 
         [0059]    It will be appreciated that a screw and screw nut such as screw  42  and screw nut  46  shown previously may be used instead of a draw bar  158  and lever  162 , and that a draw bar and lever may equally be used in the wrench shown in  FIGS. 1-12 . 
         [0060]    The wrench is used in the manner discussed above. The wrench jaws  34 ′ are placed into a riser pipe which is to be extracted. The lever  162  is then moved to pull the draw bar  158  and base plate  154  upwardly and expand the wrench jaws  34 ′ to grip the pipe. The handle  22  is then turned to extract the riser pipe. The lever  162  is then released to allow the draw bar  158 , base plate  154 , and wrench jaws  34 ′ to move downwardly and release the engagement of the wrench jaws  34 ′ and the pipe riser. A spring  166  or other biasing element may be used (in the grooves formed in the wrench jaws) to aid in releasing the wrench jaws  34 ′. 
         [0061]    There is thus disclosed an improved pipe extraction tool. It will be appreciated that numerous changes may be made to the present invention without departing from the scope of the claims.