You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a fishing tool for fishing sucker rods, tubing, pipe, pumps, plungers, plugs, tubing stops, packers, tools, anchors, obstructions, etc. from downhole in a subterranean well, such as but not limited to an oil producing, gas producing, injection or disposal well. More specifically, the fishing tool of the present invention is strong enough to retrieve up to 12,000 feet of rod at once, is designed to reduce stress on the tool so that it can be reused multiple times, is serviceable because it can be disassembled and repaired in the field, and is versatile since it can be combined with bells, adapters and other existing types of rod fishing equipment and accessories to successfully retrieve a wide range of items from subterranean wells. One or more extension pieces can be added to the body of the fishing tool to effectively lengthen the tool and thereby increase its functionality. 
         [0003]    2. Description of the Related Art 
         [0004]    Prior art fishing tools generally are of three types: tools that are overshot sockets, tools that bite and tools that are traps. An example of an overshot socket type tool can be found in U.S. Pat. No. 1,869,861 issued to O&#39;Bannon. These socket type of tools are designed to telescope over the part left in the well and interlock therewith to permit withdrawal of the part from the well by the tool. One problem with the socket type tools is that they are designed to catch only on specific shaped items and therefore are limited in the types of items with which they can interlock. Also, the proper socket size must be used for the item to be fished. When the item shape and size is unknown, the operator must play a guessing game to find a socket that is the proper size to work. This often results in the several different sizes of sockets having to be run into the well before the proper socket size can be found. This is expensive in terms of time and manpower to try again and again to get the proper socket size for the specific situation. Furthermore the sockets have a tendency of slipping open when hardened, hard lined, brass, out of round or worn couplings are being fished. Lastly, the sockets generally last for only one or two uses and become worn easily. 
         [0005]    The second type is a biter type tool. The biting type of tool is also known as a slip socket which should not be confused with the overshot socket type tool. An example of a biter type tool can be found in U.S. Pat. Nos. 1,620,382 and 1,620,383 issued to O&#39;Bannon. These biter types of tools are designed to receive the part left in the well within biting members, such as collets, which can be moved inward to bite into the part to attach the part to the tool in order to permit withdrawal of the part from the well by the tool. One problem with the biter type tools is that they are attempting to bite into a hard surface and therefore can slip. Also, the teeth of the biter type tool are only designed to catch the round rod body section of a sucker rod, and not the other items such as the bead, wrench flat, pin shoulder, pin thread or coupling. Furthermore the teeth on the slips generally only last for one or two uses before becoming worn off. Therefore the slips need to be replaced often between uses. 
         [0006]    The third type is a trap type tool. These trap type tools have a mechanism that traps the part inside the tool so that the part is captured therein and can be removed from the well with the tool. An example of a trap type tool is taught in U.S. Pat. No. 1,634,935 issued to Donnelly. In that patent, a hinged lift is provided within the tool so that after a shoulder of the part passes the lift, the lift springs back downward and traps the part within the tool. The lift of this invention is weak. Also, the tool is limited on the sizes of rods it can catch, limited on where it can catch the rod. The tool can become wedged and therefore limits the amount of pressure that this tool can exert when pulling an item from a well. 
         [0007]    Another example of a trap type tool is taught in U.S. Pat. No. 1,720,692 issued to Reynolds et al. This invention employs a slip which is pushed upward within the tool as the item enters the tool and then slides back downward below a shoulder of the item as the item moves upward and away from the slip through an opening provided in the side of the tool. By sliding under the shoulder of the item, the slip traps the item within the tool as the tool is raised within the well, thereby allowing the item to be removed from the well by the tool. 
         [0008]    The prior art mousetrap tools have several problems. First, because this type of tool is welded together, the barrel of this type of tool is weak and cannot withstand large lateral strains such as those imposed on it when the slip and the item being pulled are wedge between the walls of the barrel. Also, the top of this type of tool is also welded to the barrel portion and this creates another weak area where the tool will break. A further problem with this type of tool is that the side opening provided in the barrel of the tool is located above the shoulder of the slip, causing the item to create a sideways pull and torque moment on the tool as the item is pulled. This torque moment imposes stress on the tool that causes the barrel of the tool to split open and fail. Still a further problem with this tool is that it cannot be made in the sizes that are needed in the field. The geometry of the tool makes the walls too thin to hold the weight and tension of the rod string being pulled from the well. The rod string is also known as simply the rod, as working string, wire line tool string, or as tool string. A further problem with the tool is the way in which the slip is retained within the barrel of the tool. The slip is retained by shoulders that project into the barrel of the tool and retain the slip therein. There are two ways in which these shoulders are constructed, both of which are described in the Reynolds et al. patent. The first way is to mill slots into the interior surface of the barrel and then weld key stock into the slots to form the shoulders. The other way is to roll over the edges of two halves of the metal that will form the two halves of the barrel and then weld the two halves together to form the barrel with the rolled over edges forming the internal shoulders inside the barrel. The problem with these shoulders is that they can become bent and can prevent the slip from moving up and down within the barrel of the tool. When this happens, the tool is unable to attach to a rod and cannot fish rod out of the well. Because the shoulders of prior art tools are either welded within the tool or formed as an integral part of the barrel of the tool, once they become damaged, they cannot be economically repaired or replaced. This results in the tool no longer being functional and the tool must then be discarded. 
         [0009]    Still a further problem with prior art fishing tools is that because their body is a fixed length and their bodies cannot be lengthened, they are unable to catch certain types of breaks, such as rod breaks where the broken length of rod exceeds the length of the body of the fishing tool, thus making it impossible for the fishing tool to be lowered sufficiently around the broken rod for the fishing tool to engage one of the protrusions on the well string which can be gripped by the slip of the fishing tool. Steel sucker rods are normally twenty five feet long and fiberglass rods can be up to thirty five feet long. There are no tools within the industry today that can catch fiberglass sucker rods or successfully catch polished rods that break in the body. Fiberglass sucker rods will simply tear if biter type tools are used and also sometimes fiberglass rods will flare out slightly at the end of the break, making it difficult for the rod body to fit into a biter type tool. Polished rods are the very top rod on a rod string. Therefore they are hardened to prevent wear which makes them very difficult to fish with biter type tools. 
         [0010]    Because of all these weaknesses in this tool, it generally will only be a single use tool and it can only pull approximately 5,000 pounds of force without breaking. 
         [0011]    The present invention is a trap tool that addresses the problems found in prior art fishing tools. The design of the present tool is much stronger, has less stress concentrations, and no bending moments or torque when pulling. The present invention has increased wall thickness, is made of single pieces of metal that are threaded together or otherwise removably connected together instead of being welded together, and is designed to create a straight upward pull on the tool instead of a sideways force when pulling an item out of a well. Therefore, it can retrieve up to approximately 12,000 feet of rods at a time without breaking or withstand approximately 40,000 pounds of tension. The present tool is durable, reusable, reliable, has a long service life. 
         [0012]    The cross sectional geometry design of the present invention allows for critical sizes to be made and allows a variety of sizes to be offered. In fact, nine sizes of the invention will be made available to the purchasing public. This allows the invention to be constructed so that it can fish ¾ inch to ⅞ inch SH or slim hole couplings in 2⅜ inch tubing which is not possible with prior art tools. Slim hole couplings have the same outside diameter as the shoulder on the sucker rod whereas standard couplings have outside diameters that are larger than the shoulder of the sucker rod. 
         [0013]    The present invention is a catch-all design that does not require the use of multiple sizes of sockets, such as required by overshot socket types of fishing tools. The present tool eliminates the need for oversized tools, sockets, grapples and overshots. 
         [0014]    Further, this tool will catch hard lined couplings, fiberglass, worn or out of round couplings. This tool is provided with a threaded bottom end so that a variety of sizes of bells or adaptors can be employed with the tool. This tool can fish trashy rods from a well when an optional bottom piece with lip guide is used with the tool that assists in feeding the rods into the tool. The lip guide also allows the fishing tool to be utilized in horizontal wells. In horizontal wells the lip guide will guide the broken rod into the tool by rotating the tool from the surface. The lip will catch the rod and pull it over to the center of the fishing tool. 
         [0015]    The design of the present tool allows it to be made with a smaller outer diameter which allows it to fit through crimped or bend tubing or tubing that is filled with scale or debris. Also the smaller diameter allows for fluid to more freely flow around the outer diameter of the tool. The design of the present tool allows the tool to be screwed apart so that additional features can be added to the tool and each part of the tool can be replaced or repaired in the field. Because the present tool is constructed of parts that thread together, the top portion of the tool can be removed and the tool can be attached to another tool, such as for example the O&#39;Bannon biting type tool previously discussed, so that the two tools can be employed together, when it is desirable to do so. 
         [0016]    Some operators will leave this fishing tool in the tubing during pumping. This is generally done when a rod is parted and the tool is deployed to fish the parted rod. Then, for some reason such as a stuck insert pump, time constraints, or for other reasons the tool is left in the tubing while latched onto the broken rod and the well is simply put back on to production with the tool being utilized as a coupler to mend the parted rod. Then the tool is retrieved the next time the well is pulled or when the tubing and or sucker rods must be pulled. This type of use will occur with this tool. 
         [0017]    The present invention is also economical because it is reusable, field servable, and it is competitively priced. The present invention is also economical because it can produce a cost savings of approximately $10,000 to $30,000 per job on a deep well. 
         [0018]    The present invention is also provided with one or more extension pieces that can be inserted in the middle of the tool to thereby extend the effective length of the body or barrel of the fishing tool so that the tool can be used to catch rod breaks. Specifically, by employing extension pieces in the present fishing tool, it is able to swallow the entire rod body length and to catch the enlarged section, bead or coupling located below the rod body break. This enables the present invention to catch fiberglass sucker rods that part in either the rod body or section area break, catch steel sucker rods that part in the body, and catch hardened polished rods that part in the body. 
       SUMMARY OF THE INVENTION 
       [0019]    The present invention is a fishing tool for fishing sucker rods, tubing, pipe, pumps, plungers, plugs, tubing stops, packers, tools, anchors, obstructions, etc. from downhole in a subterranean well. The tool functions by trapping a broken sucker rod or other item to be fished out of the well within a barrel part of the tool&#39;s body by means of a combination of a movable slip provided within the barrel part and a side opening provided in the barrel part. The body of the tool is constructed of parts that are each machined from single pieces of metal stock and provided with threads so that the pieces can be secured together to form the body. The body is comprised of a top piece and a barrel piece, and normally also is provided with a bottom piece. A slip, preferable constructed of cast metal, is movably retained within the body. The slip serves to hold the rod within the barrel piece of the tool so that the rod or other item to be fished out of the well can be removed from the well by the tool. 
         [0020]    The top piece of the body is constructed of a solid metal stock and is provided with male threads on its top end for securing the tool to a rod string and with male threads on its bottom end for securing the top piece to the barrel piece of the tool. The top piece is also provided with a fluid channel extending from the bottom of the top piece to a flattened wrench flat on the top piece in order to provide fluid communication through the top piece. The purpose of the channel is to allow liquids that are trapped either above or below the top piece to move through the channel as the tool is raised and lowered within the well tubing of the well. 
         [0021]    The barrel piece of the body is constructed of hollow tube stock. The barrel piece is provided with female threads on its top end for securing the barrel piece to the male threads provided on the bottom end of the top piece and provided with female threads on its bottom end for securing the barrel piece to the bottom piece. Internally the barrel is machined to provide two parallel, longitudinally oriented grooves in which the slip is movably retained within the barrel. The slip is inserted into the barrel with ears of the slip inserting in the longitudinal grooves before the bottom piece of the body is secured to the barrel piece so that the bottom piece then captures the slip within the barrel portion when the bottom piece is attached to the barrel piece. Because the bottom piece secures the slip within the barrel, in order to replace the slip, the bottom piece is unthreaded from the barrel piece and then the slip can readily be removed from the barrel and replaced, if desired. 
         [0022]    The barrel piece is provided with a side opening that extends down and terminates on its lower end so that its lower end is level with the upper shoulder of the slip when the slip is at its lowest position. The position of the lower end of the side opening relative to the upper shoulder of the slip at it&#39;s lowest position is important for the proper function of the tool because it insures that when a rod is attached to the tool, the pulling force is directed vertically on the tool and there is no sideways pull on the tool. 
         [0023]    The body is normally also provided with a bottom piece, although, the bottom of the barrel piece can optionally be welded shut to permanently retain the slip within the longitudinal grooves and the bottom of the barrel piece can be internally beveled instead of being provided with female threads at its bottom end. 
         [0024]    However, the normal configuration is to have a bottom piece attached at the bottom end of the barrel piece. The bottom piece is also constructed of hollow tube stock. The top end of the bottom piece is provided with male threads for engaging the female threads provided on the bottom end of the barrel piece in order to secure the bottom piece to the barrel piece. The bottom end of the bottom piece is enlarged externally to help in centering the tool within the tubing and is beveled internally to aid in feeding rod into the barrel of the tool. 
         [0025]    Optionally, the bottom piece can be replaced by one of several sizes of existing bells. The bell can either be threaded directly onto the female threads provided on the bottom end of the barrel piece if the bell is provided with male threads that are compatible therewith, or alternately, can be secured to the barrel piece with an appropriate adaptor. The bell serves to guide the tool through larger size pipe interiors such as larger tubing sizes or production casing. The bell serves to guide the parted rod into the tool and allows the tool to stay centered in the pipe. 
         [0026]    The slip is in a half moon shape, with its externally facing wall convex in shape and its internally facing wall concave in shape. Two ears are provided on the external surface of the slip for movable engagement with the longitudinal grooves provided internally within the barrel, as previously described. The bottom edge of the slip is beveled on its internally face in a half moon configuration to provide for smooth engagement of the slip with the rod as the rod enters the tool and pushes the slip upward. The top end of the slip is provided with a square shoulder against which an expanded surface of the rod or other item to be pulled will engage the slip as the tool is raised, as will be further described herein. 
         [0027]    An optional slip can be employed instead of the standard slip. The optional slip is provided with a serrated or toothed shoulder on its top end instead of a square shoulder. The purpose of the teeth or serrations is to resist rotational slippage of the caught rod. The teeth are milled into a standard slip and are added to allow the tool to more easily be backed-off from downhole. Also, the teeth allow the tool to be more easily used when a rod on/off tool must be unlatched from downhole. 
         [0028]    Depending on where the break in the rod string occurs, the shoulder of the slip on the present invention can engage any enlarged area of the broken rod string, including an upper or lower bead of a rod, an upper or lower shoulder of a rod, or a rod coupling. 
         [0029]    One limitation of the present invention is that it is not able to catch on a straight rod if the rod is parted more than ten inches above a rod coupling. However, the present invention can be coupled with an existing biting type fishing tool, such as an O&#39;Bannon slip socket, in order to additionally catch those types of breaks. As previously stated, the biting type of tool is also known as a slip socket. 
         [0030]    In order to attach a biting type fishing tool such as the O&#39;Bannon device to the present invention, first the top piece of the present invention is removed from the barrel piece and then the bottom piece of an O&#39;Bannon type combination overshot socket device is removed from its top piece. Next, the barrel piece of the present invention is attached to the top piece of the O&#39;Bannon type device. The barrel piece of the present invention may be attached to the top of piece of the O&#39;Bannon type device either by directly threading the two parts together if their threads are compatible, or alternately, by employing an adaptor to secure them together if their threads are not compatible. 
         [0031]    In order to extend the effective length of the body of the fishing tool, the top piece can be unthreaded from the barrel piece and one or more extension pieces can be threadably secured between the top piece and the barrel piece. Extending the effective length of the body of the fishing tool allows the tool to be used to catch a rod body break, on either a fiberglass rod, steel sucker rod or hardened polished rod. By adding one or more extension pieces to the fishing tool, the fishing tool can then swallow the rod body and catch the enlarged section, bead or coupling located below the rod body break. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]      FIG. 1  is a side view of a fishing tool for fishing sucker rods out of a well constructed in accordance with a preferred embodiment of the present invention. 
           [0033]      FIG. 2  is a front view of the tool taken along line  2 - 2  of  FIG. 1 . 
           [0034]      FIG. 3  is an enlarged view of the top piece of the tool associated with numeral  3  of  FIG. 1  shown removed from the tool. 
           [0035]      FIG. 4  is a front view of the top piece of the tool taken along line  4 - 4  of  FIG. 3 . 
           [0036]      FIG. 5  is a top view of the top piece of the tool taken along line  5 - 5  of  FIG. 3 . 
           [0037]      FIG. 6  is a bottom view to the top piece of the tool taken along line  6 - 6  of  FIG. 3 . 
           [0038]      FIG. 7  is a cross sectional view taken along line  7 - 7  of  FIG. 4 . 
           [0039]      FIG. 8  is a cross sectional view taken along line  8 - 8  of  FIG. 4 . 
           [0040]      FIG. 9  is a side view of the barrel piece of the tool associated with numeral  9  of  FIG. 1  shown removed from the tool. 
           [0041]      FIG. 10  is a front view of the barrel piece of the tool taken along line  10 - 10  of  FIG. 9 . 
           [0042]      FIG. 11  is a side view of the bottom piece of the tool associated with numeral  11  of  FIG. 1  shown removed from the tool. 
           [0043]      FIG. 12  is a bottom view of the bottom piece of the tool taken along line  12 - 12  of  FIG. 11 . 
           [0044]      FIG. 13  is a cross sectional view of the bottom piece of the tool taken along line  13 - 13  of  FIG. 11 . 
           [0045]      FIG. 14  is a front view of the slip of the tool associated with numeral  14  of  FIG. 2  shown removed from the tool. 
           [0046]      FIG. 14A  is a perspective view of the slip of  FIG. 14 . 
           [0047]      FIG. 14B  is a perspective view of an alternate slip. 
           [0048]      FIG. 15  is a top view of the slip taken along line  15 - 15  of  FIG. 14 . 
           [0049]      FIG. 16  is a cross sectional view of the slip taken along line  16 - 16  of  FIG. 14 . 
           [0050]      FIG. 17  is a cross sectional view taken along line  17 - 17  of  FIG. 10 . 
           [0051]      FIG. 18  is a cross sectional view taken along line  18 - 18  of  FIG. 10 . 
           [0052]      FIG. 19  is a cross sectional view taken along line  19 - 19  of  FIG. 10  with the slip shown in outline to indicate where it would normally be located. 
           [0053]      FIG. 20  is a cross sectional view taken along line  20 - 20  of  FIG. 10 . 
           [0054]      FIG. 21  is a side view similar to  FIG. 11  of an alternate bottom piece of the tool. 
           [0055]      FIG. 22  is a bottom view of the alternate bottom piece of the tool taken along line  22 - 22  of  FIG. 21 . 
           [0056]      FIG. 23  is a cross sectional view of the alternate bottom piece of the tool taken along line  23 - 23  of  FIG. 21 . 
           [0057]      FIG. 24  is a side view of a bell for optional replacement of the bottom piece of the tool. 
           [0058]      FIG. 25  is a cross sectional view of the bell taken along line  25 - 25  of  FIG. 24   
           [0059]      FIGS. 26-31  are perspective views of the steps involved in engaging a broken rod string located within a well with the tool. 
           [0060]      FIG. 32  is a perspective view of the tool of  FIG. 1 . 
           [0061]      FIG. 33  is an enlarged view of a section of rod string to be fished with the tool. 
           [0062]      FIG. 34  is a top view of the broken rod string taken along line  34 - 34  of  FIG. 33   
           [0063]      FIG. 35  is an enlarged side view of a tool that is constructed without a bottom piece. 
           [0064]      FIG. 36  is an enlarged view of the tool and broken rod string from within circle  36  of  FIG. 31 . 
           [0065]      FIG. 37  is a side view of the fishing tool of  FIG. 1  shown with an extension piece added between the top piece and the barrel piece. 
           [0066]      FIG. 38  is a front view of the tool with extension piece added taken along line  38 - 38  of  FIG. 37 . 
           [0067]      FIG. 39  is a perspective view of a typical rod break in a rod string. 
           [0068]      FIG. 40  is a perspective view showing the typical rod break of a rod string of  FIG. 39  being caught by the tool with extension piece of  FIG. 38 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0069]    Referring now to drawings and initially to  FIGS. 1 ,  2 ,  26  and  32 , there is illustrated a fishing tool  10  for fishing sucker rods  12 , tubing, pipe, etc. from downhole in a well  14 . The body of the tool  10  is constructed of parts or pieces  16 ,  18  and  20  that are each machined from single pieces of metal stock and provided with threads so that the pieces  16 ,  18 , and  20  can be secured together to form the body of the tool  10 . As shown in  FIGS. 1 and 2 , the body is comprised of a top piece  16  and a barrel piece  18 , and normally also is provided with a bottom piece  20 . A slip  22 , preferable constructed of cast metal, is movably retained within the body, as will be more fully described hereafter. The slip  22  serves to hold the rod  12  within the barrel piece  18  of the tool  10  so that the rod  12  or other item to be fished out of the well  14  can be removed from the well  14  by the tool  10 . 
         [0070]    Referring now to  FIGS. 3 ,  4 ,  5 ,  6 ,  7 , and  8 , the top piece  16  of the body is constructed of a solid metal stock and is provided with male threads  24  on its top end  26  for securing the tool  10  to a rod string  12  and with male threads  28  on its bottom end  30  for securing the top piece  16  to the barrel piece  18  of the tool  10 . The top piece  16  is also provided with a fluid channel  32  extending from the bottom end  30  of the top piece  16  to a flattened wrench flat  34  on the top piece  16  in order to provide fluid communication through the top piece  16 . The purpose of the channel  32  is to allow liquids that are trapped either above or below the top piece  16  to move through the channel  32  as the tool  10  is raised and lowered within the well  14 . 
         [0071]    Referring to  FIGS. 9 ,  10 ,  17 ,  18 ,  19  and  20 , the barrel piece  18  of the body is constructed of hollow tube stock. The barrel piece  18  is provided with female threads  35  on its top end  38  for securing the barrel piece  18  to the male threads  28  provided on the bottom end  30  of the top piece  16  and provided with female threads  40  on its bottom end  42  for securing the barrel piece  18  to the bottom piece  20 . Internally the barrel piece  18  is machined to provide two parallel, longitudinally oriented grooves  44  in which the slip  22  is movably retained within the barrel piece  18 . These grooves  44  are milled with a rounded radius  46  at each of the edges, as shown in  FIG. 20 . The rounded radius  46  is employed instead of a pointed or squared off edge because this reduces the stress concentration at this point, thereby allowing the tool  10  to be stronger. The slip  22  is inserted into the barrel piece  18 , with matching rounded ears  48  of the slip  22  inserting in the longitudinal grooves  44  before the bottom piece  20  of the body is secured to the barrel piece  18  so that the bottom piece  20  then captures the slip  22  within the barrel piece  18  when the bottom piece  20  is attached to the barrel piece  18 . Having the bottom piece  20  also makes the tool  10  stronger by eliminating a shear plane of a weld at this point. 
         [0072]    Because the bottom piece  20  secures the slip  22  within the barrel piece  18 , in order to replace the slip  22 , the bottom piece  20  is unthreaded from the barrel piece  18  and then the slip  22  can readily be removed from the barrel piece  18  and replaced, if desired. The barrel piece  18  is provided with a side opening  50 . As shown in  FIGS. 18 and 19 , the walls adjacent to the side opening  50  are parallel with each other, thus allowing a rod coupling to move outward through the side opening  50 , as will be more fully described hereafter. The side opening  50  extends down and terminates on its lower end  52  so that its lower end  52  is level with an upper shoulder  54  of the slip  22  when the slip  22  is at its lowest position. The slip  22  is shown in its lowest position in  FIGS. 1 ,  2 ,  26 ,  27 ,  28 ,  30 ,  31 , and  36 . The position of the lower end  52  of the side opening  50  relative to the upper shoulder  54  of the slip  22  when the slip  22  is at its lowest position is important for the proper function of the tool  10  because it insures that when a rod  12  is attached to the tool  10 , the pulling force exerted on the tool  10  is directed vertically on the tool  10  and there is no sideways pull on the tool  10 . 
         [0073]    Referring to  FIGS. 11 ,  12 , and  13 , the body is normally also provided with a bottom piece  20  that attaches at the bottom end  42  of the barrel piece  18 . The bottom piece  20  is also constructed of hollow tube stock. Male threads  56  are provided on the top end  58  of the bottom piece  20  for engaging the female threads  40  provided on the bottom end  42  of the barrel piece  18  in order to secure the bottom piece  20  to the barrel piece  18 . The bottom end  60  of the bottom piece  20  is enlarged externally to help in centering the tool  10  within the well casing or the well  14  and is provided with an internal bevel  62  to aid in feeding rod  12  into the barrel piece  18  of the tool  10 . 
         [0074]    Optionally, as illustrated in  FIGS. 21 ,  22  and  23 , an alternate bottom piece  20 A can be employed that has a lip guide  64  provided in the bevel  62  of the bottom end  60  to facilitate guiding the rod  12  into the tool  10 , particularly when the rod  12  is bent or when the well  14  is filled with debris or scale. The optional lip guide  64  provides the tool  10  with the ability to rotate over the parted rod  12 . This is valuable because in most cases the parted rod  12  is up against the side of the inner wall of the tubing  100 . Sometimes it is freely against the wall and can easily move to the center when the tool  10  sides over it to catch it. But sometimes the parted rod  12  is bent or kinked over to the side of the wall, thereby making it more difficult to side over to the center. The lip guide  64  provides a gripping surface to rotate the rod  12  over toward the center so that it can more easily enter the tool  10 . 
         [0075]    Also, as illustrated in  FIGS. 24 and 25 , the bottom piece  20  can be replaced by one of several sizes of existing bells  66 . The replacement bell  66  can either be threaded directly onto the female threads  40  provided on the bottom end  42  of the barrel piece  18  if male threads  68  provided on the bell  66  are compatible therewith, or alternately, can be secured to the barrel piece  18  with an appropriate adaptor (not illustrated). The bell  66  serves to guide the tool  10  through larger size pipe interiors such as larger tubing sizes or production casing. The bell  66  serves to guide the parted rod  12  into the tool  10  and allows the tool  10  to stay centered in the pipe. Typical bells sizes are available for 3½ inch tubing, 4½ inch casing and 5½ inch casing, but other customized bells sizes can be obtained for up to 8⅝ inch casing. 
         [0076]    As illustrated in  FIG. 35 , alternately the tool  10  can be constructed without a bottom piece  20 . In this optional configuration, an alternate barrel piece  18 A is employed which has the longitudinal grooves  44  welded shut at the bottom end  42 A of the alternate barrel piece  18 A to permanently retain the slip  22  within the longitudinal grooves  44 . Also, the bottom end  42 A of the alternate barrel piece  18 A is provided internally with a bevel  70  to guide the rod  12  into the tool  10  instead of being threaded. 
         [0077]    Referring to  FIGS. 14 ,  14 A,  15  and  16 , the slip  22  is in a half moon shape, with its externally facing wall  72  being convex in shape and its internally facing wall  74  being concave in shape. Two ears  48  are provided one on either edge of the external wall  72  of the slip  22  for movable engagement with the longitudinal grooves  44  provided internally within the barrel piece  18 , as previously described and illustrated in  FIG. 19 . Also, the internal wall  74  of the slip  22  is provided at its bottom edge  76  with a half moon shaped bevel  78  to provide for smooth engagement of the slip  22  with the rod  12  as the rod  12  enters the tool  10  and pushes the slip  22  upward. As previously described, the upper shoulder  54  that is provided in the top end  80  of the slip  22  is square. The square shoulder  54  and provides a surface against which an expanded surface of the rod  12 , or other item to be pulled, will engage the slip  22  as the tool  10  is raised after the rod  12  has entered the barrel piece  18  and after the slip  22  has moved back downward to its lowest position, as will be more fully explained hereafter. 
         [0078]    As illustrated in  FIG. 14B , an optional slip  22 A can be employed instead of the standard slip  22 . The optional slip  22 A is similar to the standard slip  22  except it is provided with a serrated or toothed shoulder  54 A on its top end  80 A instead of a square shoulder  54 . The purpose of the teeth  82  or serrations is to resist rotational slippage of the caught rod  12 . To create the alternate slip  22 A, teeth  82  are milled into a standard slip  22 . The teeth  82  are added to allow the tool  10  to more easily be backed-off from downhole. Also, the teeth  82  allow the tool  10  to be more easily used when a rod on/off tool must be unlatched from downhole. 
         [0079]    Some downhole pumps are not pulled out when the rods  12  are pulled out of the well  14 . These types of pumps are called tubing pumps. They are installed on the bottom of the tubing  100  and are retrieved from the well  14  when the tubing  100  is retrieved. However, rods  12  are still used. But there is a tool on the bottom of the rod string  12  called a sucker rod on/off tool. This on/off tool latches onto the top of the pump when the rods  12  reach it and stay latched on until it is unlatched. To unlatch from it, the work over rig operator must rotate the rod  12  which unlatches the rod on/off tool. In order for the sucker rod fishing tool  10  to be able to transfer this rotation to the rod on/off tool, it must resist rotational slippage between the tool  10  and the broken rod  12 . The teeth  82  on the top end  80 A of the alternate slip  22 A help resist this slippage. 
         [0080]    In some cases insert tubing pumps will become stuck in the tubing  100 , i.e. in the seating nipple. Then the tool  10  may need to be backed off from. In this case the operator rotates the sucker rods  12  counter-clockwise to unscrew the rods  12  or clockwise when a back-off tool with left hand threads is utilized directly above the tool  10 . The tool  10  will also need to resist this rotation in order to be backed off from. 
         [0081]    Referring to  FIGS. 33 and 34 , there is illustrated a section of a typical rod string  12  showing a connection of an upper rod  12 U to a lower rod  12 L via a rod connector or coupling  12 C. The coupling  12 C shown in  FIG. 33  is a standard coupling since its outside diameter is greater than the outside diameter of the shoulders  90  and  92  of the sucker rod. Beginning at the top of  FIG. 33  and moving downward, the upper rod  12 U is provided with a rod portion  84 , an enlarged diameter bead  86 , a reduced diameter wrench flat  88 , and an enlarged diameter shoulder  90 . The female threaded rod coupling  12 C attaches to male threads (not illustrated) provided on a lower end of the upper rod  12 U so that the coupling  12 C abuts the enlarged diameter shoulder  90  of the upper rod  12 U when the upper rod  12 U is threaded together with the coupling  12 C, as shown in the  FIG. 33 . 
         [0082]    Still referring to  FIG. 33 , and moving below the coupling  12 C, the lower rod  12 L is likewise provided with a male threads (not illustrated) provided on the upper end of the lower rod  12 L and with an enlarged diameter shoulder  92  that abuts the coupling  12  when the lower rod  12 L is threaded into the coupling  12 C, as shown in  FIG. 33 . The lower rod  12 L then has a reduced diameter wrench flat  94 , an enlarged diameter bead  96  and a rod portion  98 . This illustration of this section of rod string  12  is provided to help illustrate the enlarged areas  86 ,  90 ,  12 C,  92  and  96  on a broken rod string  12  that can be caught by the present tool  10 . 
         [0083]    Depending on where the break in the rod string  12  occurs, the shoulder  54  of the slip  22  on the present invention can engage an upper or lower bead  86  or  96  of a rod  12 , an upper or lower shoulder  90  or  92  of a rod  12 , or a rod coupling  12 C. One limitation of the present tool  10  is that it cannot engage the rod portion  84  or  98  of the rod  12 . However, if the rod  12  parts at the rod portion  84  of the rod  12  within ten inches or less distance from above the rod coupling  12 C the present tool  10  can still retrieve it at any of the aforementioned locations  86 ,  96 ,  90 ,  92 , or  12 C. However, as is discussed hereafter, the present tool  10  can be attached with other existing fishing tools to address this limitation. 
         [0084]    Referring now to  FIGS. 26 ,  27 ,  28 ,  29 ,  30 ,  31 , and  36 , the steps involved in fishing a rod  12  from a well  14  with the present tool  10  are illustrated.  FIG. 26  illustrates the tool  10  being lowered within the well tubing  100 , casing or open hole and approaching the upper end  102  of a broken rod string  12  that is to be fished out of the well  14 . 
         [0085]      FIG. 27  shows the tool  10  lowered further so that there is initial engagement of the upper end  102  of the broken rod string  12  with the bottom piece  20  of the tool  10 . This illustration shows how the internal bevel  62  in the bottom piece  20  guides the broken rod string  12  into the tool  10 . 
         [0086]      FIG. 28  shows the tool  10  being lowered still further so that the tool  10  telescopically receives the broken rod string  12  within the tool  10 . This figure also shows the initial engagement of the upper end  102  of the broken rod string  12  with the slip  22 . 
         [0087]      FIG. 29  shows the tool  10  lowered further, the broken rod string  12  received further into the tool  10 , and the slip  22  being pushed upward within the barrel piece  18  of the tool  10  by the broken rod string  12 . 
         [0088]      FIG. 30  shows the broken rod string  12  moving into the side opening  50  provided in the barrel piece  18  which allows the slip  22  to slide downward within the barrel piece  18  past enlarged area or areas  86 ,  96 ,  90 ,  92 , or  12 C of the broken rod string  12  until the slip  22  is located at its lowest possible position within the tool  10 . Once the slip  22  has moved into this position, the tool  10  is then ready to be raised. 
         [0089]    Another way that the tool  10  can catch a broken rod sting  12  will be described. When the rod  12  enters the tool  10 , it pushes the slip  22  upward to the uppermost position of the slip  22 , i.e. at the top end of the grooves  44 . As the tool  10  travels further downward within the well  14 , the rod  12  travels upward within the tool  10  and along the slip  22 . The rod  12  then exits the side opening  50  as the tool  10  continues moving downward. The tool  10  continues to move downward until the broken upper end  102  of the rod  12  contacts the top piece  16 . When the end  102  contacts the top piece  16 , the tool  10  stops moving downward which signals the operator to begin raising the tool  10  within the well  14 . At this point the slip  22  is either located at its lowest most position or is still at the top end of the grooves  44 . If the slip  22  is still located at the top end of the grooves  44 , when operator starts to raise or pick up the tool, one of the edges  86 ,  96 ,  90 ,  92 , or  12 C of broken rod  12  will engage the upper shoulder  54  on the slip  22  and drag it back down to its lowest position, i.e. to the bottom end of the grooves  44 . The top ends of the grooves  44  stop short of the upper end of the side opening  50  so that the tool  10  will function properly to allow the parted rod  12  to move upward beyond the top end of the grooves  44  and still exit through the side opening  50 . 
         [0090]      FIG. 31  shows the tool  10  being raised with the broken rod string  12  secured thereto.  FIG. 36  shows an enlarged view of the relative positions of the tool  10  and the broken rod string  12  illustrated in  FIG. 31 . Referring to  FIG. 36 , as the tool  10  is initially moved upward, the shoulder  54  of the slip  22  engages an enlarged area  86 ,  96 ,  90 ,  92 , or  12 C of the broken rod string  12  that it previously slipped past. The enlarged areas  86 ,  96 ,  90 ,  92 , or  12 C of the broken rod string  12  may not all exist on the broken piece left in the well and this depends on where the break takes place. Different sections in different instances will be caught depending on where the break takes place. Simultaneously, the same enlarged area  86 ,  96 ,  90 ,  92 , or  12 C of the broken rod string  12  will also engage the lower end  52  of the side opening  50  of the barrel piece  18 . The lower end  52  of the side opening  50  of the barrel piece  18  and the slip  22  thus function together to capture the broken rod string  12  within the tool  10  and to keep the rod string  12  centered within the tool  10 . The shoulder  54  of the slip  22  and the lower end  52  of the side opening  50  of the barrel piece  18  are level at this time. This arrangement is important in that it prevents any sideway force from being exerted on the tool  10  as a pulling force is exerted on the tool  10  in order to pull the broken rod string  12  out of the well  14 . 
         [0091]    One limitation of the present invention is that it is not able to catch on a rod  12  where the break is at the straight rod portion  84  or  98  of a rod string  12 . However, if the rod parts at the straight rod portion  84  of the rod  12  within ten inches or less from above rod coupling  12 C the present tool  10  can still retrieve it at any of the aforementioned locations  86 ,  96 ,  90 ,  92 , or  12 C. However, the present invention  10  can be coupled with an existing biting type fishing tool, such as an O&#39;Bannon slip socket, in order to additionally catch those types of breaks. 
         [0092]    In order to attach a biting type tool such as the O&#39;Bannon device to the present invention, first the top piece  16  of the present tool  10  is removed from the barrel piece  18  and then a bottom half of an O&#39;Bannon tool is removed from its top half. Next, the barrel piece  18  of the present tool  10  is attached to the top half of the O&#39;Bannon combination overshot socket tool. The barrel piece  18  of the present tool  10  may be attached to the top half of the O&#39;Bannon tool either by directly threading the two parts together if their threads are compatible, or alternately, by employing an adaptor (not illustrated) to secure them together if their respective threads are not compatible. 
         [0093]    Referring to  FIGS. 37 and 38 , there is illustrated the fishing tool  10  which has had the top piece  16  disconnected from the barrel piece  18  and had one or more extension pieces  103  inserted between the top piece  16  and the barrel piece  18 , thereby extending the effective length of the body or barrel piece  18  of the fishing tool  10 . With the extension in effective length, the tool  10  can be used to catch broken rods  12  such as the one illustrated in  FIG. 39  where the length  109  of the broken rod  12 , i.e. the length from the broken upper end  102  of the broken rod  12  to the bead  86  on the sucker rod  12 , would exceed the length of the barrel piece  18  alone. Each extension piece  103  is a hollow pipe or tube that is threaded at both ends. An adapter  104  is shown connecting the extension piece  103  to the barrel piece  18  of the fishing tool  10 . The extension piece  103  and adaptor  104  have outside diameters  105  and  107 , respectively, which are preferably approximately the same as an outside diameter of the barrel piece  18  of the fishing tool  10 . The inside diameter  106  of the extension piece  103  and the inside diameter  108  of the adaptor  104  are preferably approximately the same as an inside diameter of the barrel piece  18  of the fishing tool  10 . 
         [0094]      FIG. 40  illustrates how the fishing tool of  FIGS. 37 and 38  that has been effectively lengthened by the use of one or more extension pieces  103  is used to swallow the entire rod body length  109  of the broken rod  12  illustrated in  FIG. 39  and to catch the enlarged section or shoulder  92 , bead  86  or coupling  12 C located below the broken rod  12 . By using one or more extension pieces  103  inserted into the body of the fishing tool  10 , this enables the tool  10  to catch fiberglass sucker rods that part in either the rod body or section area break, catch steel sucker rods that part in the body, and catch hardened polished rods that part in the body. 
         [0095]    Further, although not specifically illustrated, the fact that the present fishing tool  10  threads together in pieces, this allows a variety of threaded accessories to be connected to the top, the bottom or in the middle of the tool  10 . These threaded accessories may include, without limitation, cameras, lead impression plates or blocks, adaptors, pipe extensions, bells, mill shoes, and other special ends and tools. While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the embodiments set forth herein for the purposes of exemplification, but is to be limited only by the scope of the attached claim or claims, including the full range of equivalency to which each element thereof is entitled.

Summary:
A fishing tool for fishing sucker rods from a subterranean well. The tool is a top piece, a barrel piece and bottom piece that all thread together. One or more extender sections are added by unthreading the top piece from the barrel piece and threading the extender sections therebetween to effectively lengthen the barrel piece and increase its functionality. The bottom piece retains a curved cast metal slip movable within grooves milled internally into the body. A lower end of a side opening provided in the barrel piece is level with an upper shoulder of the slip when the slip is at its lowest position. Optionally, the bottom piece can be replaced with a bell, lip guide, mill shoe, or other types of tools and the top piece can be replaced by a prior art fishing tool or other tools.