Abstract:
A pulling tool comprises an air-powered internal anvil and hammer. The pulling tool is attached to the object to be removed. The hammer is urged by pressurized air to repeatedly strike the anvil, which applies a percussive force to the object, progressively removing the object from its housing. A conventional air hammer can be modified into a tool puller by replacing the air hammer bit with a cap, and attaching the object to the rear of the air hammer through a coupler. Alternatively, a cylindrically-shaped collar is slidably secured over a conventional air hammer. A pulling bit slidably communicates with a flanged rod attached to the object to be removed. Operation of the air hammer causes the pulling bit to strike the flange, progressively removing the object from its housing.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. provisional application Ser. No. 60/319,362, filed Jun. 27, 2002, which is incorporated herein in its entirety. 

   BACKGROUND OF INVENTION 
   1. Field of the Invention 
   This invention relates to a pneumatically-driven tool. In one aspect, the invention relates to a device for the extraction of frictionally-fit fittings and tooling bits. 
   2. Description of the Related Art 
   Mechanical assemblies frequently utilize friction-fit components, such as fittings and tool bits, which must at times be separated. Friction pins, for example, can be used to hold two parts together. If the parts must be separated, the pin must first be removed. Generally, this is accomplished by repeatedly striking the pin with a hammer. Similarly, bearings are frequently press-fit into a housing. Removal of the bearing from the housing involves pulling or repeatedly striking the bearing until it is released. Other friction-fit or press-fit assemblies can occasionally require removal of the friction-fit or press-fit component from the remainder of the assembly. 
   A conventional way of removing a friction-fit or press-fit component is by rigidly attaching a pulling or pushing member to the component and applying a percussive force to the pulling member and thus to the component to be removed. The percussive force is developed by repeated striking of a heavy hammer against the member to progressively move the component out of its housing. The hammer is typically operated by hand. Consequently, the repetitive striking force can fatigue the operator and may even cause injury, particularly repetitive-motion injury. 
   Another means of removing a friction-fit or press-fit component is by use of a hydraulic puller comprising a hydraulic piston and cylinder assembly with a pulling member attached to the piston. The pulling member is attached to the object to be removed. The hydraulic cylinder assembly is attached to a stationary base, which is fixed with respect to the object. Hydraulic pressure is applied to the piston by a hydraulic pump, which causes the object to be removed from its housing. The hydraulic puller can comprise a relatively large assembly, which may be inconvenient or impractical for certain applications. As well, proper alignment of the device with the object to be removed may be difficult. 
   Yet another means is to utilize a screw-type puller in which a threaded pulling member is attached to the object and a mating threaded collar is turned against a base, gradually pulling the threaded rod and the removing attached object from the housing. As with the hydraulic puller, the screw-type puller can comprise a relatively large device having a base which must be properly aligned with the object to be removed in order to operate effectively. 
   The conventional pullers described above are frequently slow and require complicated assemblies which must be properly aligned with the object to be pulled and stabilized against the large pulling force that must be developed to remove the object. Human input is generally physically taxing. Shock to the various parts of the hands, arms and shoulders can cause fatigue and injury. 
   SUMMARY OF INVENTION 
   In one embodiment of the invention, a tool for removing a friction-fit or press-fit component from a seat comprises a hand-held, pneumatically-driven hammer for applying a repeating percussive force, and a coupling for interconnecting the hammer and the component, wherein the repeating percussive force is applied to the component thereby urging the component from the seat. The hammer can comprise a tool body comprising an anvil and enclosing a piston, wherein the piston strikes the anvil to apply the percussive force to the tool body. The coupling can interconnect the tool body and the component. 
   The tool can further comprise a spring adapted to urge the piston away from the anvil after the application of the percussive force. The coupling can comprise a tool holder, a coupling adapter, and a rod puller, and the coupling adapter can be adapted to transfer the percussive force from the tool holder to the rod puller. The coupling adapter can be adapted to enable the rod puller to translate relative to the tool holder. The coupling can comprise a sleeve adapted to slidably communicate with an exterior surface of the hammer and fixedly retain the hammer therein. 
   The tool can further comprise a pulling bit attached to the hammer and adapted to apply the percussive force to the component. The coupling can be attached to a forward end of the hammer or a rearward end of the hammer. 
   The tool can further comprise a cap having an anvil attached to the hammer for transmitting a percussive force applied to the anvil through the hammer to the component. 
   In another embodiment, an adapter for converting an air hammer with a reciprocating member into a tool for removing a friction-fit or press-fit component from a seat comprises a pull rod adapted to be attached to the component, and a hammer piece attached to the reciprocating member and adapted to percussively communicate with the pull rod, wherein the reciprocating member imparts a reciprocating motion to the hammer piece so that a repeating percussive force is applied to the pull rod by the hammer piece thereby urging the component from the seat. The coupling can comprise a sleeve adapted to slidably communicate with an exterior surface of the hammer and fixedly retain the hammer therein. A pulling bit can be attached to the hammer and adapted to apply the percussive force to the component. 
   In another embodiment, a method for removing a friction-fit or press-fit component from a seat comprises the steps of fixedly coupling a pull rod to the component so that an impact force delivered to the pull rod will be transmitted to the component, fixedly coupling the pull rod to a hand-held, pneumatically-driven hammer adapted to apply a repeating percussive force to the pull rod, and activating the hammer to apply a repeating percussive force to the pull rod, and thereby urge the component from the seat. The method can further comprise the steps of replacing a hammer bit with a cap, wherein the cap is adapted to transmit a percussive force applied thereto to the hammer, replacing the hammer bit with a pulling bit, wherein the pulling bit is adapted to transmit the percussive force from the hammer to the component, and coupling the pull rod to a rear portion of the pneumatically-driven hammer. 
   In yet another embodiment, a kit for converting an air hammer into a tool for removing a friction-fit or press-fit component from a seat, the air hammer comprising a body and a reciprocating member comprises a pull rod attached to the component, and a pulling member attached to the air hammer and adapted to percussively communicate with the pull rod. 
   In yet another embodiment, a hand-held, pneumatically-driven hammer comprises a mounting portion at a rear portion of the hammer, the mounting portion being adapted to fixedly couple a component thereto, the component being frictionally retained in a component seat, wherein the hammer is adapted to be a tool puller for removing the component from the component seat. The mounting portion can comprise threads adapted for threadable connection with the component, a bayonet-type connection, or a collar and at least one set screw. 

   
     BRIEF DESCRIPTION OF SEQUENCES 
     In the drawings: 
       FIG. 1  is a side view of a first embodiment according to the invention comprising a pneumatic percussive pulling tool. 
       FIG. 2  is an end view from the rear of the pneumatic percussive pulling tool of  FIG. 1 . 
       FIG. 3  is a cutaway view of the interior of the pneumatic percussive pulling tool of  FIG. 2 . 
       FIG. 3A  is a fragmentary sude elevational view showing a portion of the air hammer of  FIG. 3  in greater detail. 
       FIG. 4A  is a perspective view of a second embodiment according to the invention comprising an air hammer housing for converting an air hammer to a pneumatic percussive pulling tool. 
       FIG. 4B  is a top plan view of the air hammer housing of  FIG. 4A . 
       FIG. 5A  is a perspective view of a pulling bit comprising a part of the air hammer bit of  FIG. 4A . 
       FIG. 5B  is a side elevational view of the pulling bit of  FIG. 5A . 
       FIG. 5C  is an end elevational view of the pulling bit of  FIG. 5A . 
       FIG. 6  is a perspective view of the pulling bit of  FIG. 5A  assembled over an air hammer. 
       FIG. 7  is a cutaway view of the assembly of  FIG. 6 . 
       FIG. 8  is a cutaway view of a third embodiment according to the invention comprising a pneumatic percussive pulling tool. 
       FIG. 9  is a cutaway view of a fourth embodiment according to the invention comprising a pneumatic percussive pulling tool. 
       FIG. 10  is a cutaway view of a fifth embodiment according to the invention comprising a cap and adapter for converting an air hammer to a pneumatic percussive pulling tool. 
       FIG. 11  is a partial sectional view of the air hammer shown in  FIG. 10  prior to conversion to a pulling tool. 
       FIG. 12  is an exploded view of the air hammer shown in  FIG. 11  illustrating a first step in the conversion of the air hammer to a pulling tool. 
       FIG. 13  is an exploded view of the air hammer shown in  FIG. 11  illustrating a second step in the conversion of the air hammer to a pulling tool. 
   

   DETAILED DESCRIPTION 
   Referring now to  FIG. 1 , a first embodiment of the invention comprising a pneumatic percussive pulling tool  10  is shown. The pulling tool  10  comprises a tool body  12  and a rod assembly  14 . The tool body  12  is a generally cylindrically shaped body having a hollow interior, as shown in  FIG. 3 , to which are rigidly attached handles  16 ,  18  extending laterally therefrom, as shown in  FIG. 2 , thereby providing a tool having the general configuration of a conventional hammer drill. The handle  18  comprises a trigger  20  for activating the pulling tool  10 . 
   The tool body  12  comprises an anvil cap  22  and a cylinder body  24 . The anvil cap  22  is a generally cuplike member having an open end  23  and a closed end  25 . The open end  23  is provided with female threads  26  extending circumferentially around the interior thereof. The closed end  25  comprises a cylindrically-shaped anvil  28  coaxial with the anvil cap  22  and extending into the interior thereof. A spring  30  is slidably received over the anvil  28  to extend into the cylinder body  24  when the anvil cap  22  is connected to the cylinder body  24  as hereinafter described. 
   The cylinder body  24  comprises a proximal end  11  and a distal end  13 . The proximal end  11  is provided with male threads  32  adapted to matingly engage the female threads  26  of the anvil cap  22  and thereby secure the anvil cap  22  to the proximal end  11  of the cylinder body  24 . The distal end  13  of the cylinder body  24  is adapted to receive the rod assembly  14 , as hereinafter described. 
   The cylinder body  24  comprises a generally cylindrically-shaped cylinder cavity  34  coaxial with the cylinder body  24 , opening toward the proximal end  11 , and closed at the distal end  13 . The cylinder cavity  34  comprises a first portion  35  having a first diameter adapted to slidably receive a piston  36  and a second portion  37  having a second, larger diameter adapted to slidably receive a ram  38 . Intermediate the distal end  13  and the proximal end  11  are a plurality of exhaust ports  42  extending laterally outwardly from the cylinder cavity  34  to the exterior of the cylinder body  24 . As shown in  FIG. 3 , the exhaust ports  42  are inclined toward the distal end  13 . The preferred embodiment comprises two exhaust ports  42  comprising elongated cylindrical passageways having a diameter adapted to control the exhaustion of pressurized air from the cylinder body  24 . 
   As shown in  FIGS. 2 and 3 , the cylinder body  24  is provided with air supply passageway  44  fluidly interconnecting a conventional air inlet  46 , a conventional air regulator  48 , the trigger  20 , and the cylinder cavity  34 . The air inlet  46  is adapted to fluidly interconnect to a conventional supply of pressurized air  62  utilizing conventional pressure fittings. The air regulator  48  is adapted to regulate the pressure of the air delivered to the cylinder cavity  34 . The trigger  20  is adapted to allow the passage of the air from the regulator  48  to the distal end  13  of the cylinder cavity  34  when the trigger  20  is activated, such as by manual depression. 
   The piston  36  slides within the cylinder cavity  34  and is urged toward the proximal end  11  when pressurized air is introduced into the distal end  13  of the cylinder cavity  34  through the air supply passageway  44 . A valve assembly  40  is installed at the closed end of the cylinder cavity  34  and fluidly interconnected with the air supply passageway  44 . The valve assembly  40  is adapted to deliver a selected volume of pressurized air into the cylinder cavity  34  sufficient to move the piston  36  the required distance for operation of the pulling tool  10 . 
   A coupler is used to connect the tool body  12  to the rod assembly  14 . As shown in  FIGS. 1 ,  3 , and  3 A, a first embodiment of the coupler is shown comprising a rod connector  50  comprising a generally cylindrical body rigidly attached to the distal end  13  of the cylinder body  24 , axially aligned therewith, and adapted to rigidly connect the cylinder body  24  to the rod assembly  14  through a tool holder  52 , such as by a threaded connection for threading the tool holder  52  into the rod connector  50 . The tool holder  52  is a generally rod-like member having an annular flange  78  at a free end thereof, adapted to slidably communicate with a coupling adapter  56  for connecting the tool holder  52  to a puller rod  58 . The coupling adapter  56  is a hollow, generally cylinder-shaped body having a tool holder end  66  and a pull rod end  68 . The coupling adapter  56  comprises an annular wall  70  defining a cylindrical chamber  76  adapted to slidably receive the annular flange  78 . The annular wall  70  terminates at the tool holder end  66  in an inwardly-extending annular shoulder  72  defining a tool holder aperture  74  adapted to slidably receive the tool holder  52 . The annular shoulder  72  is adapted to operably cooperate with the annular flange  78  to prevent the separation of the tool holder  52  from the coupling adapter  56 . The tool holder  52  slidably receives a spring  54  therearound, which is in contact with the rod connector  50  and the coupling adapter  56 , and which is adapted to urge the annular flange  78  against the annular shoulder  72 . The puller rod  58  is an elongated generally rod-like member rigidly connected to the coupling adapter  56  at the puller rod end  68  and adapted to be removably connected, such as by a threaded connection, to a fitting  60  frictionally or press-fit into a seat for removal of the fitting  60  from the seat using the pulling tool  10 . 
   The operation of the pulling tool  10  will now be described. The pulling tool  10  is connected to the air supply  62  and to the fitting  60  to be removed. An operator grasps both handles  16 ,  18  exerting a slight pulling force on the pulling tool  10  and the fitting  60 . The operator the depresses the trigger  20  which delivers pressurized air through the passageway  44  to the valve assembly  40 . The valve assembly  40  delivers a preselected volume of highly pressurized air to the cylinder cavity  34 , accelerating the piston  36  towards the ram  38  and the proximal end  11 , the piston  36  impacts the ram  38 , propelling it into the anvil  28 , compressing the spring  30 . As the ram  38  impacts the anvil  28 , the piston  36  clears the exhaust ports  42 , and the pressurized air in the cylinder cavity  34  is exhausted through the exhaust ports  42 . With the pressurized air removed from the cylinder cavity  34 , the spring  30  urges the piston  36  and the ram  38  back toward the distal end  13 , when the process is repeated. The rapid succession of impacts of the ram  38  against the anvil  28  drives the tool puller  10  away from the fitting  60 , gradually extracting the fitting  60  from the seat. 
   The rapid return of the piston  36  and the ram  38  toward the distal end  13  caused by the spring  30  exerts a force on the pulling tool  10  toward the fitting  60 , which would tend to drive the fitting  60  back in place, thereby preventing its removal. The spring  54  and the sliding coupling adapter  56  absorb the forward-directed shock from the tool puller  10 , thereby preventing the fitting  60  from being driven back into the seat by the rebound of the pulling tool  10 . 
   Referring now to  FIGS. 4–7 , a second embodiment of the invention is shown comprising an air hammer housing  80  adapted for conversion of a conventional air hammer  88  into a pulling tool. In this embodiment, the air hammer housing  80  comprises the coupling and the anvil assembly. Referring to  FIGS. 4A–4B , the air hammer housing  80  comprises a sleeve portion  82 , a pull rod support assembly  84 , and a pulling bit  86 . The sleeve portion  82  is a generally cylindrically-shaped body, having a proximal end  81  and a distal end  83 , comprising a hollow tube  90  and a longitudinally-extending channelway  92  extending the length of the sleeve portion  82 . Diametrically opposite to the channelway  92  at the proximal end  81  is a handle cutout  94  adapted to receive the handle of the air gun  88 , as hereinafter described. At the proximal end  81  are a pair of diametrically-opposed mounting blocks  96  adapted to threadably receive a threaded connection  100 , such as a cap screw. A plurality of stop blocks  95  comprising generally rectilinear block-like bodies are fixedly attached to the inside surface  97  of the sleeve portion  82  near the distal end  83 . 
   The pull rod support assembly  84  comprises an arcuate band  98 , a rod guide support block  102 , and a rod guide  104 . The arcuate band  98  is provided with an aperture at each end axially aligned with an aperture in each mounting block  96  for receipt of the threaded connector  100  therethrough. The rod guide support block  102  is a rectilinear, somewhat elongated block-like body having a first end  101  and a second end  103 . The first end  101  is rigidly attached to the midpoint of the arcuate band  98  to extend laterally therefrom. The rod guide  104  is a generally cylindrical collar-like body rigidly attached at its circumference to the second end  103  of the rod guide support block  102  so that the axis of the rod guide  104  is orthogonal to the axis of the arcuate band  98 . The pull rod support assembly  84  is attached to the sleeve portion  82  with the threaded fasteners  100  so that the arcuate band  98  extends diametrically across the sleeve portion  82  and the axis of the rod guide  104  is parallel to the axis of the channelway  92  and the axis of the sleeve portion  82 . 
   Referring to  FIGS. 5A–5C , a pulling bit  86  is an irregularly-shaped body comprising a retaining flange  108 , a rod portion  110 , and a hammer portion  112 . The retaining flange  108  is adapted to rigidly connect the pulling bit  86  to a hammer rod  106  as shown in  FIGS. 5A and 7 . The rod portion  110  is a generally rod-like member axially aligned with the retaining flange  108 , in axial alignment with the hammer rod  106 . The hammer portion  112  comprises a hammer  114  rigidly connected in a longitudinal direction to a flange  116  which is in turn rigidly connected to the rod portion  110  extending laterally therefrom. The hammer  114  is a generally cylindrical collar-like body having an aperture  118  therethrough. A conventional return spring  97  retains the pulling bit  86  to the air hammer  88  in a well-known manner. 
   Referring to  FIG. 6 , a rod  120  is an elongated rod like member adapted to be slidably inserted through the apertures  105  and  118 , and attached through suitable means at a first end  122  to the fitting to be removed (not shown). A second end  124  of the pull rod  120  terminates in a circular flange  126  having a diameter somewhat greater than the diameter of the pull rod  120 . The flange  126  is adapted to bear against the hammer  114 . Or, alternatively, a common, manual slide-hammer rod can be used without departing from the scope of this invention. 
   Referring to  FIGS. 6 and 7 , the air hammer housing  80  is assembled to an air hammer  88  by inserting the air hammer  88  into the air hammer housing  80  so that the air hammer handle extends through the handle cutout  94 . The arcuate band  98  is attached to the sleeve portion  82  so that the air hammer  88  is forcibly held against the stop blocks  95  by the arcuate band  98 . The pulling bit  86  is attached to the hammer rod  106  through the retaining flange  108  so that the pulling bit  86  extends through the upper slot  92 . The pull rod support assembly  84  is attached to the sleeve portion  82  so that the aperture  118  is axially aligned with the aperture  105 . The pull rod  120  is first inserted through the aperture  118  followed by the aperture  105 , and the first end  122  is rigidly attached to the fitting to be removed. The assembly is then brought toward the second end  124  of the pull rod  120  so that the flange  126  bears against the hammer  114 . The air hammer  88  is actuated so that the hammer  114  repeatedly strikes the flange  126 , transmitting a percussive pulling force to the fitting and thereby removing the fitting. 
     FIG. 8  illustrates a third embodiment of the invention comprising a pneumatic percussive pulling tool  130  which is similar in most respects to the pulling tool  10  shown in  FIGS. 1–3 . Thus, like numerals will be used to identify like elements. The pulling tool  130  differs from the pulling tool  10  in that the pulling tool  130  comprises a single cylinder-shaped piston  136  rather than the combined piston  36  and ram  38  of the pulling tool  10 . Furthermore, the piston  136  travels in a cylinder cavity  134  having a constant diameter, rather than the dual-diameter cylinder cavity  34  of the pulling tool  10 . 
   The pull rod  58  of the pulling tool  130  is attached directly to the rod connector  50  rather than through a tool holder  52 , spring  54 , and coupling adapter  56 , as with the pulling tool  10 . A spring in communication with the anvil  28  is unnecessary for returning the piston  136  to the distal end  13  of the tool body  12  at the completion of each stroke. The pulling tool  130  operates in the same manner as the pulling tool  10 . 
     FIG. 9  illustrates a fourth embodiment of the invention comprising a pneumatic percussive pulling tool  140  which is similar to the pulling tool  130  shown in  FIG. 8 , with the exception of the handle and the attachment of the pulling tool  130  to the rod assembly  14 . Thus, like numerals will be used to identify like elements. 
   The pulling tool  140  comprises a cylinder  142  having a closed proximal end  144  and an open distal end  146 . The proximal end  144  comprises an anvil wall  148 . A cylindrical bore  150  extends from the anvil wall  148  to the distal end  146  and is adapted to slidably receive a piston  152 . A handle  154  is attached to the proximal end  144 . An air supply passageway  44  extends through the handle  154  from the regulator  48 , through the trigger  24  in fluid communication with the valve assembly  40 . 
   A tool cap  156  is a generally cylindrical body having at one end an annular wall defining a cylinder well  158  which is adapted to fixedly receive the distal end  146  of the cylinder  142 , preferably by means of a threaded section  159 . The end of the tool cap  156  is provided adjacent its perimeter with a plurality of evenly-spaced threaded wells  162  adapted for threadable receipt of cap screws  170 . A shallow, cylindrical pull rod chamber  160  is centered coaxially in the end of the tool cap  156 . 
   A tool rod coupler  164  is a generally cylindrical-shaped body adapted for cooperative communication with the tool cap  156 . A plurality of cap screw apertures  168  is provided adjacent its perimeter in mating coaxial alignment with the threaded wells  162  so that the cap screws  170  can be inserted through the apertures  168  to be threaded into the threaded apertures  162  to attach the tool cap  156  to the tool rod coupler  164 . The coupler  164  is also provided with a pull rod aperture  166  extending coaxially therethrough for mating communication with the pull rod chamber  160 . A pull rod  174  is an elongated rod-like member comprising a shaft  176  and a flange head  178 . The shaft  176  is adapted for slidable communication with the pull rod aperture  166 , and the end of the flange head  178  is adapted for cooperative receipt in the pull rod chamber  160 . When the coupler  164  is attached to the tool cap  156  with the pull rod  174  installed in the pull rod chamber  160 , the pull rod  174  will be fixedly attached to the tool cap  156  and, thus, to the percussive pulling tool cylinder  142 . 
   The operation of the percussive pulling tool  140  is generally the same as previously described. Compressed air delivered through the valve assembly  40  into the bore will drive the piston  152  against the anvil wall  148 . The percussive force will be applied through the cylinder  142  to the tool cap  156  and the coupler  164 , and thence to the pull rod  174  and the item to be removed. 
     FIGS. 10 and 13  illustrate a fifth embodiment of the percussive pulling tool which comprises a conventional air hammer  88  which has been modified into a pulling tool. The air hammer  88  is provided with a cylinder portion  182  defining an internal cylindrical chamber  186  and a cylindrical piston  188  adapted for slidable movement within the chamber  186 . As compressed air is delivered to the chamber  186 , the piston  188  is urged to the front of the air hammer  88  in a well-known manner. 
   Looking at  FIGS. 11 and 12 , the air hammer  88  is typically provided with a hammer bit  196  terminating at one end in an anvil  198 . The air hammer  88  is also provided with a coil spring  200  which is adapted to be threaded onto a threaded spring mount  202  extending coaxially from the end of the cylinder  182 . An aperture  184  extends through the threaded spring mount  202  to communicate with the chamber  186 . The bit  196  is attached to the cylinder  182  by inserting the anvil  198  through the aperture  184  and threading the coil spring  200  onto the threaded spring mount  202 . The coil spring  200  and the hammer bit  196  are adapted for cooperative communication so that the spring  200  retains the anvil  198  in the aperture  184  while allowing slidable movement of the hammer bit  196  relative to the cylinder  182 . As the piston  188  is urged by the compressed air to strike the anvil  198 , the hammer bit  196  will be driven away from the cylinder  182 . However, the spring  200  will extend with the movement of the hammer bit  196  and will prevent the hammer bit  196  from being expelled from the air hammer  88 , in a well-known manner. 
   Referring again to  FIGS. 10 and 13 , a pull cap  180  is a generally cylindrical-shaped body having an annular wall  194  at one end and a cylindrical anvil post  190  extending coaxially relative to the annular wall  194 . The annular space between the annular wall  194  and the anvil post  190  is provided with cap threads  204  adapted for threadable communication with the threaded spring mount  202 . Additionally, set screws can be used to secure the pull cap  180  to the spring mount. The cap  180  is threaded onto the cylinder  182  so that the anvil post  190  extends through the aperture  184  into the chamber  186 , and the cap  180  will be fixedly attached to the cylinder  182 . When the piston  188  strikes the anvil post  190 , the impact will be transmitted through the cap  180  to the cylinder  182  and the body of the air hammer  88 . 
   The butt end of the air hammer  88  is modified with a seat  61  for attachment of the pull rod  58  thereto. Preferably, the seat  61  is threaded and the pull rod  58  is attached by threading a threaded stud  59  therein. The fitting  60  is fixedly attached to the tool assembly  64  as previously described. Thus, percussive force applied to the body of the air hammer  88  will be transmitted to the pull rod  58  and the tool assembly  64  (i.e., the fitting to be removed) for removal of the tool assembly  64  from its seat. Alternatively, the seat  61  can be adapted for attachment of the pull rod  58  in a well-known manner through a collar and one or more radially-oriented set screws, or a bayonet-type connection. 
   The unique invention described herein is easy to assemble and use. In the embodiments shown herein, the invention provides a way to use an existing air hammer as a pulling tool and, in other embodiments, a new-style air hammer body and attachments are shown that provide a way by which an air hammer can be easily used as a pulling tool. The invention requires only a single supply of readily available pressurized air. The invention eliminates the manual effort and impact stresses to the operator resulting from the use of the prior art pullers, thus minimizing fatigue and injury to the operator. With the easily-assembled, hand-held assembly, fittings can be quickly pulled, thereby minimizing downtime and improving productivity. 
   While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.