Abstract:
An apparatus and method for creating a flange around a preformed opening in a wall of a tubular member. The apparatus includes an elongated guidance housing adapted to fit within the tubular member. An elongated presser having at least one pressing surface is slidably received within the guidance housing. A punch member is located adjacent the pressing surface within the guidance housing. The punch member is sized to fit at least partially through a side opening in the guidance housing and at least partially through the preformed opening. When the presser is advanced relative to the guidance housing, the pressing surface to urges the punch-through the side opening and through the preformed opening. The movement of the punch thereby forms an outwardly upstanding annular flange extending around the preformed opening in the tubular member.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to machining processes. In particular, the present invention relates to an apparatus and method for forming flanged openings in objects where access to certain areas may be difficult or undesired.  
           [0002]    In typical machining processes, openings are formed in metal or plastic objects using techniques such as drilling or punching. These techniques are most often performed by orienting the object to be machined perpendicularly to a drill bit or punch.  
           [0003]    Due to particularities of some processes, however, openings may need to be formed on objects where normal access by a drill bit or punch is not possible. For example, a relatively small opening may need to be formed in a distal end of a long section of sealed pipe after connection to another sealed object. Because of the nature of this configuration, it may not be possible to introduce a tool to drill the opening after the connection is made. The solution to this problem would typically involve the steps of drilling concentric openings in each object before connection. The numerous steps involved in drilling the individual objects and precisely aligning them together for connection may prove difficult, expensive and time-consuming for the manufacturer.  
           [0004]    Some applications require formed openings to include a short flange or rim annularly defined around a round opening. This flange is used to facilitate welding of the object to another object and to ensure a complete seal around the opening after the weld. An example of such an application is the configuration of a 0.5-inch manifold pipe used in automobile applications. To manufacture the proper configuration, is necessary to attach threaded joints to the sidewalls of a narrow, bent section of the thin aluminum tubing. A drilled, round opening is formed in the sidewall concentrically with the joint attachment point to allow airflow through the sidewall and into the joint.  
           [0005]    The attachment of the threaded joints to the pipe requires strong, airtight welds nearly normally to the sidewalls of the tubing. To ensure the strength and integrity of the welds, it is preferable to form an outwardly facing, annular flange around the opening in the sidewall before attachment of the threaded joint. To best form this joint, it is preferable or desired to machine the flange from the interior side of the tubing in order to ensure a uniform flange rim that faces outwardly in a desired direction. However, as in the hole-forming processes described above, access to the interior of the tubing is difficult for conventional tooling. Thus, the flange must be formed by inserting a punch tool from the exterior side of the tubing into a pre-formed, drilled opening in the sidewall. The tool is expanded within the opening and is withdrawn from the tube with force, thereby bending the rim of the opening slightly toward the exterior of the pipe.  
           [0006]    This rim-forming process has serious shortcomings. Most significantly, the withdrawal of the tool from the hole does not produce a uniform flange, but rather a flange that is uneven and includes cracks caused by fatigue of the surrounding metal. The poor quality of the flange can seriously compromise the weld or brace used to attach the threaded joint to the tubing. Other methods have been utilized, such as welding exterior flanges around the tubing, but these operations are very costly and difficult to perform.  
           [0007]    Therefore, there is a need for a tooling operation and apparatus for forming openings and flanges in objects where access to the object from the exterior is difficult or unpreferred.  
         SUMMARY OF THE INVENTION  
         [0008]    To alleviate the shortcomings noted above and in the prior art, an apparatus and method are provided herein to create a flange around a preformed opening in a wall of a tubular member. In one aspect of the present invention, the apparatus includes an elongated guidance housing adapted to fit within the tubular member. An elongated presser having at least one pressing surface is slidably received within the guidance housing. A punch member is located adjacent the pressing surface within the guidance housing. The punch member is sized to fit at least partially through a side opening in the guidance housing and at least partially through the preformed opening. When the presser is advanced relative to the guidance housing, the pressing surface to urges the punch through the side opening and through the preformed opening. The movement of the punch thereby forms an outwardly upstanding annular flange extending around the preformed opening in the tubular member.  
           [0009]    In another aspect of the invention, an apparatus for forming an opening in a wall of a tubular member includes an elongated guidance housing adapted to fit within the tubular member. The guidance housing defines a hollow interior space and at least one side opening. An elongated presser having at least one pressing surface is slidably received within the interior space of the guidance housing. A punch member sized to fit at least partially through the side opening is located adjacent to the pressing surface within the interior space. The advancement of the presser relative to the guidance housing causes the pressing surface to urge the punch through the side opening and through a wall of the tubular member.  
           [0010]    In yet another aspect of the apparatus of the present invention, the guidance housing defines a hollow interior space and at least one side opening. The elongated presser slidably received within the interior space of the guidance housing includes a distal end, a flanged end, and at least one sloped pressing surface sloping toward the flanged end and the side opening in the guidance housing. A floating punch member is received within the interior space of the guidance housing and is placed in contact with the sloped pressing surface of the presser. The floating punch member is sized so that at least a portion of the punch member is receivable through the side opening. The advancement of the presser relative to the guidance housing causes the pressing surface to urge the floating punch through the side opening and through a sidewall of the tubular member.  
           [0011]    The invention may also be embodied in a system provided in conjunction with the preferred apparatus. The system includes a pressurizable cylinder linked to the presser in the apparatus. A pump is also provided to pressurize the cylinder, and a clamping device is used to hold and reinforce at least a portion of the tubular member.  
           [0012]    The invention may be further embodied in a method of forming an opening in the sidewall of a tubular member. The method includes the steps of inserting an elongated guidance housing into the tubular member, inserting a floating punch member into the interior space, and inserting an elongated presser into the interior space of the guidance housing. The presser includes at least one sloped pressing surface, wherein the insertion of the presser captures the punch member between the sloped pressing surface and the side opening of the guidance housing. The presser is then advanced relative to the guidance housing within the tubular member. This causes the pressing surface to push the floating punch through the side opening and through a sidewall of the tubular member. 
       
    
    
       [0013]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. The invention, together with further objects and attendant advantages, will best be understood by reference to the following detailed description, taken in conjunction with the accompanying drawings.  
       BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a perspective exploded view of a first embodiment of the apparatus of the present invention.  
         [0015]    [0015]FIG. 2 is an assembled perspective view showing the apparatus of FIG. 1.  
         [0016]    [0016]FIG. 3 is a cutaway view of the apparatus of FIG. 1 showing the apparatus in use.  
         [0017]    [0017]FIG. 4 is the same view of the apparatus as in FIG. 3, showing a flange being progressively formed.  
         [0018]    [0018]FIG. 5 is the same view of the apparatus as in FIG. 4, showing a flange being progressively formed.  
         [0019]    [0019]FIG. 6 is a schematic diagram showing the apparatus of FIG. 1 implemented in a system of the present invention.  
         [0020]    [0020]FIG. 7 is a perspective view of a second preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    Referring now to the drawings, in particular FIG. 1, a forming apparatus  10  includes a guidance housing  12 , a presser  14 , and a punch  16 . In preferred embodiment, the guidance member  12  is formed from a tubular steel tube having a distal end  18  and a mounting end  20 . Proximate to the mounting end  20 , an annular mounting flange  22  is preferably integrated to the guidance member  12 . The distal end of the guidance housing  12  preferably defines a front side opening  24  into the axially extending hollow space defined within the member  12 .  
         [0022]    An elongated opening  26  is defined proximate the distal end  18  of a guidance housing  12  axially along a cylindrical side of the tube. The opening  26  preferably includes a curved front end face  28  closest to the distal end  18 . Side edges  30  extend axially along the housing  12  toward a rear edge  32 , which is also preferably of a semicircular curve shape.  
         [0023]    Presser  14  is preferably formed from solid steel cylindrical stock preferably about 0.442 inches in diameter. The circumference of the presser  14  is sized to fit closely within the interior circumference of the guidance housing  12 . The presser  14  includes a distal end  40  and a rear end  42 . Beginning at the distal end  40  of the presser  14  and extending rearwardly toward a center of the length of the cylinder is a flattened pressing surface  44  machined into the cylinder shape of the presser  14 . Preferably, the pressing surface  44  is divided into a horizontal section  44   a  and at least one ramped or wedged section  44   b . The horizontal section  44   a  preferably is 0.5 inches in length and is shorter than the ramped section  44   b . An elongated, shallow guidance groove  46  is defined centrally along the surface sections  44   a  and  44   b  and extends substantially along the lengths of the surface sections. The groove is preferably 0.1 inches wide and defines an interior, cross-sectional radius of approximately 0.1 inches. The groove preferably extends approximately 2.0 inches along the horizontal axis. The ends of the slot  46  include semicircular edges  48  preferably approximately 0.05 inches in radius.  
         [0024]    It has been found that the ramped or wedged surface section  44   b  performs best when the surface  44   b  is machined to an angle of 170 degrees with the horizontal plane along the axis of the presser  14 . A tolerance of plus or minus 0.05 degrees has also been found to provide acceptable results for the presently preferred application. The ramped or wedged section  44   b  preferably extends approximately 1.875 inches along the horizontal axis. Of course, these and other specific measurements may vary in accordance with the particular requirements of the application and are not meant to be limiting herein.  
         [0025]    A second elongated positioning slot  50  extends diametrically through the cylinder  53  of the presser  14 , and extends in axial alignment with the groove  46 . The slot  50  extends within the area bounded by the surface section  44   b  and the rear end  42  of the presser  14 . Preferably, the slot  50  is about 0.167 inches wide and includes curved end portions  54  preferably having a radius of 0.08 inches. The remaining, non-machined portions of the presser  14  preferably form right cylindrical walls  58  which are sized to fit within the hollow bore of the guidance member  12 . Thus, the presser  14  may be slidably received within the guidance member  12 , and force applied longitudinally to the rear end  42  of the presser  14  relative to the guidance housing  12  forces the pressing surface sections  44   a  and  44   b  to move forwardly underneath the opening  26  in the guidance housing  12 .  
         [0026]    When the presser  14  is properly positioned within the guidance housing  12 , an alignment pin  60  may be inserted through the cylinder  22  or the rear end of the guidance member  12  and at least partially through the slot  50  in the presser  14 . The alignment pin  60  prevents rotation of the presser  14  relative to the guidance housing  12 , yet allows for axial displacement of the presser  14  within the guidance housing  12 . A range of extension and insertion of the presser  14  is thus allowed identical to the length of slot  50 . Of course, other guidance mechanisms may be utilized. For example, keyed recesses and protrusions on either the sides of the presser  14  or the interior surface of the guidance housing  12  may be utilized to register the presser  14  with the housing  12 . Other alternative structures will be apparent to those skilled in the art.  
         [0027]    The assembled apparatus  10  including the presser  14  inserted within the board of the guidance member  12  is shown in FIG. 2. As shown best in FIG. 1, a punch  16 , preferably a spherical metal ball bearing, may be dropped into the slot  26  for registration with the groove  46  and pressing surface sections  44   a  and  44   b  of the presser  14 . The punch  16  also registers within the slot  26  and the interior of the guidance member  12 . The round surface of the ball bearing punch  16  allows the punch  16  to rotate relative to the curved edge  28  as the presser  14  is advanced relative to the guidance housing  12 . During this advancement, the punch  16  is gradually raised transversely out of the slot  26  as it is pushed by the gradually sloping, ramped surface section  44   b  of the presser  14 . The transverse advancement of the punch  16  is what is used to create openings or flanges.  
         [0028]    The operation of the apparatus  10  is shown in FIGS.  3 - 5 . Turning to FIG. 3, the cutaway illustration shows a tubular aluminum manifold pipe or tubular member  75  consisting of a tubular straight portion  76  and an elbow portion  77 . A preformed opening  78  has preferably been drilled in the top of the straight portion  76 . The tubular member  75  is preferably held in place by an external clamp  80  made of hardened tool steel. The clamp  80  preferably includes two halves split along a longitudinally extending face  82 . A round opening  84  is provided at the top of the clamp which allows for alignment with the preformed opening  78  in the tubular member  75 .  
         [0029]    In the present example application, it is desired for an annular flange to be formed surrounding the preformed opening  78  in the tubular member  75 . It is also desired that the flange be directed approximately 9 degrees from the normal transverse direction to allow custom installation of an angled branch connection to the member  75 . The particular configuration of the clamp openings  84  assist in directing the flange in this orientation.  
         [0030]    A forward edge  86  and a rearward edge  88  of the clamp opening  84  control the direction of flange formation. In particular, the rearward edge  88 , at its point closest to elbow  77 , includes a cross-sectional bent angle at approximately 10 degree deviation from vertical. The leading edge  86  includes a stepped tang formed in the edge as shown. In the preferred embodiment, an innermost edge  89  and an outermost edge  90  are formed of roughly equal thickness. The edges  89  and  90  are separated in the horizontal direction preferably by approximately 0.021 inches.  
         [0031]    As shown in FIG. 3, the distal end of the apparatus  10  is inserted through an open end  74  of the tubing  75 . Preferably, the leading edge  28  of the side opening  26  is aligned with the edge of the pre-formed opening  78  in the tubing  75 . By sliding the presser  14  into the position as shown, the ball-bearing punch  16  may also be aligned with the pre-formed opening  78 .  
         [0032]    Gentle forward pressure P applied to the presser  14  in the direction of the arrow shown lodges the punch  16  against the edge  28  of the opening  26  as shown.  
         [0033]    The completion of the flange forming operation around the preformed opening  78  is shown in FIGS.  4 - 5 . Referring first to FIG. 4, increased pressure P 2  is used to force the presser forward relative to the guidance housing  12 . This results in the sloped pressing surface section  44   b  urging the ball bearing punch  16  against the leading edge  28  of the side opening  26 . The groove  46  in the sloped surface section  44   b  keeps the bearing punch  16  centered on the pressing surface section  44   b  to ensure that the punch  16  remains in the axial center of the opening  26  during the formation of the flange. The punch  16  is thus driven upwardly in the direction of the vertical arrow D. In this Figure, the beginning of the formation of flange  100  around the preformed opening  78  may be seen as the punch  16 , which is slightly larger in circumference than the preformed opening  78 , bears against the rim of the preformed opening  78  and bends the rim against the edges  88  and  86  of the clamp  80 .  
         [0034]    Turning now to FIG. 5, as pressure P 2  continues to urge the presser  14  forwardly through the guidance housing  12 , the ball bearing punch  16  is finally pushed through the preformed opening  78  in the tubing  75 . This final urging of the widest diameter of the punch  16  urges the top edges of the newly formed annular flange  100  completely against the edge  88  and tang  90  of the clamp  80 . This orientation of the edges  86  and  88  of the clamp forces the punch  16  to exit the clamp portion  80  in the adjusted direction D 2 , which is approximately 10 degrees from vertical. At this point, the ball bearing punch  16  may be removed and the guidance housing  12  and presser  14  may be withdrawn from the tube  75 .  
         [0035]    Turning now to FIG. 6, a system for utilizing the apparatus  10  is shown in a schematic diagram. In particular, the apparatus  10  is shown including guidance housing  12 , a presser  14 , a punch  16  and a clamp  80 . In order to apply the proper amount of force to move the presser  14  forwardly within the guidance housing  12 , an hydraulic cylinder  200  may be provided as shown. The cylinder  200  includes a projecting piston  210  which is preferably linked to a rear end  42  of the presser  14 . Pressurization of the cylinder  200  may be accomplished by pumping either fluid or air from a hydraulic pump  220  into the cylinder  200 . The pressurization forces the piston  210  forward, which in turn forces the presser  14  forward. In the preferred embodiments, the preferred force must be applied along the axial direction of the presser  14  to form the flange in the stainless steel manifold pipe is approximately 380 in-lbs.  
         [0036]    [0036]FIG. 7 shows a second preferred embodiment of the invention. In particular, an elongated guidance housing  312  is shown having two separate side openings  326 . Aligned with these openings are dual ramped or wedged presser surfaces  344  and  345  having ramped sections  344   b  and  345   b , respectively, which are integrally formed into a single elongated presser  314 . The apparatus as shown in FIG. 7 preferably operates in substantially identical fashion to the apparatus shown in FIGS.  1 - 5 , although a separate punch may be utilized within each of the dual openings  326  to form simultaneously a flange within each of two separate preformed openings.  
         [0037]    The above preferred embodiments of the invention have been configured for use in forming openings in tubular members. It should be noted, however, that the invention may be modified to form openings in any hard-to-reach places, even in flat walls. For example, when it is required to form an opening perpendicularly to a sheet of metal in a difficult-to-access area, such as between parallel walls spaced only inches apart, the invention may be modified accordingly. In this regard, the guidance housing  12  may include means for holding the guidance housing  12  securely against a wall so that its side opening  26  is positioned against the wall. Such holding means may be implemented using suction technology or electromagnets, for example. Once the guidance housing  12  is secured against the wall, the presser  14  may be utilized to urge the punch  16  through the wall as described above. This type of configuration would allow the forming of openings without the necessity for space-consuming drill bits and their associated motor structures.  
         [0038]    Of course, it should be understood that a wide range of changes and modifications can be made to the embodiments described above. For example, the punch used to enlarge the preformed opening need not be a ball bearing. In the alternative, the punch may comprise a flap hinged to an inside of the guidance housing  12  and configured to be urged upwardly of the guidance housing through the use of a forwardly thrusting piston or presser configuration. Furthermore, the guidance housing and the presser need not be cylindrical in shape, and may comprise open interfacing cross-sectional pieces. In addition, it is important to note that the present apparatus need not be utilized solely to form flanges around pre-formed openings. Indeed, the apparatus may be used to form new openings by applying sufficient force to the punch to force it through a solid wall of an object. The apparatus is also useful for forming openings in any wall in a difficult-to-access area, as noted above. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting and that it be understood that it is the following claims, including all equivalents, which are intended to define the scope of this invention.