Abstract:
A pilot assembly and method for metal forming dies has a generally cylindrical pilot with a stripper that strips stock from the pilot when metal forming dies diverge. The pilot assembly is secured to one die member by a fastener by itself or in combination with a window mount. A spring within the pilot assembly contacts the stripper to force the stripper to reciprocate when the dies are pulled apart. Thus, the pilot assembly helps locate the stock within the metal forming die while also having a stripper to help strip the stock from the pilot.

Description:
CROSS REFERENCE TO RELATED APPLICATION AND CLAIM TO PRIORITY 
       [0001]    The present application is a continuation of commonly assigned, co-pending U.S. patent application Ser. No. 14/460,583, filed Aug. 15, 2014, entitled LOW PROFILE PILOT ASSEMBLY AND METHOD FOR METAL FORMING DIES, which is a continuation of commonly assigned U.S. patent application Ser. No. 13/971,343, filed Aug. 20, 2013 (now U.S. Pat. No. 8,844,335, issued Sep. 30, 2014), entitled LOW PROFILE PILOT ASSEMBLY AND METHOD FOR METAL FORMING DIES, which claims priority under 35 U.S.C. §119 to U.S. Provisional Application No. 61/684,492, filed Aug. 20, 2012, all of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to metal forming dies and the like, and in particular to a low profile pilot assembly and associated method. 
         [0003]    Metal forming dies, such as stamping dies and the like, are well known in the art. Progressive metal forming dies are unique, very sophisticated mechanisms which have multiple stations or progressions that are aligned longitudinally, and are designed to perform a specified operation at each station in a predetermined sequence to create a finished metal part. Progressive stamping dies are capable of forming complex metal parts at very high speeds, so as to minimize manufacturing costs. 
         [0004]    Heretofore, the dies used in metal forming processes have typically been individually designed, one of a kind assemblies for a particular part, with each of the various components being handcrafted and custom mounted or fitted in an associated die set, which is in turn positioned in a stamping press. Not only are the punches and the other forming tools in the die set individually designed and constructed, but the other parts of the die set, such as stock lifters, guides, end caps and keepers, cam returns, pilots, etc. are also custom designed, and installed in the die set. Current die making processes require carefully machined, precision holes and recesses in the die set for mounting the individual components, such that the same are quite labor intensive, and require substantial lead time to make, test and set up in a stamping press. Consequently, such metal forming dies are very expensive to design, manufacture, and repair or modify. 
         [0005]    Pilot assemblies, such as that disclosed in U.S. Pat. No. 4,342,214, are used for locating a work piece in successive forming stages of a machine, such as a punch press, where the work piece is progressively moved through the forming stages of the machine. The pilot assembly typically includes a pilot pin mounted to a movable die member of the machine for guiding entry into a previously formed hole in a work piece or in a companion die member as the die members are moved toward each other, the pin being axially retractable in its mounting in the event that it strikes an obstruction. The retraction movement of the pin may be controlled by a spring or a hydraulic mechanism which includes a hydraulic chamber formed behind the pin into which the pin moves to displace a hydraulic fluid therefrom. 
         [0006]      FIGS. 9-14  illustrate several well-known prior art metal forming dies and associated pilot mechanisms, which further represent the background of the present invention. For example,  FIG. 9  illustrates one half of a die set  100 , which includes a first die member  101  having a plurality of longitudinally spaced apart work stations  102  at which various bending, forming, cut-off and/or punching operations are performed on an elongate strip of metal stock  103 . As best illustrated in  FIG. 10 , the prior art pilot mechanism  104  for the illustrated die set  100  includes a pierce tool punch  105  located at an upstream portion of stock strip  103 , which, in the illustrated example, forms a vertically oriented through hole  106  in the stock strip  103  at regularly spaced apart intervals along the stock strip. The through holes or pilot holes  106  are selectively engaged by a series of pilot pins  107  positioned on at least selected ones of the die work stations  102 , which serve to precisely locate the stock strip  103  in the work stations, and retain the same in place during the metal forming stroke of the die tools. After each metal forming stroke of the die tools, the pilot pins  107  are retracted out of their associated pilot holes  106  in the stock strip  103 , and the stock strip  103  is then shifted longitudinally to the next adjacent work station  102 , until the metal part has been completely formed and cut off of the stock strip. When the pilot pins  107  are retracted out of the pilot holes  106  in the stock strip  103 , the stock strip tends to stick on one or more of the pilot pins, thereby requiring some type of stripper mechanism to separate them, such that the stock strip can be quickly and sequentially advanced longitudinally through the various die stations. 
         [0007]      FIG. 11  illustrates another known prior art pilot assembly that includes a rectangularly shaped block or base  111  that is mounted in a blind hole pocket  112  in an associated upper die member  113 . The base block  111  includes a central aperture  114  in which a pilot pin  115  is retained, and two laterally offset reaction apertures  116  in which a pair of stripper assemblies are received and retained. A female punch tool  117  is positioned in the lower die member  122 , and closely receives the pilot pin  115  to precisely locate the stock strip  103  in the associated work station. Each of the stripper assemblies comprises a plunger shaped rod  118  having an outer end  119  protruding outwardly from base block  111  toward the stock strip  103 , and an inner end  120  with a coil spring  121  received thereover which resiliently urges the rods  118  outwardly on opposite sides of pilot pin  115 , and serve to strip the stock strip  103  from the exterior surface of the pilot pin  115  as the pilot pin and associated upper die member  113  are raised to a diverged condition relative to the lower die member  122 . 
         [0008]      FIG. 12  illustrates yet another known prior art pilot assembly, which includes an enlarged, flat mounting plate  126  which attaches to the upper surface  127  of the upper die member  113  using a pair of cap head screws  128  having threaded shanks  129  that are anchored in the upper die member  113 . The upper die member  113  includes a central aperture  114  in which a pilot pin  115  is received and retained, along with a pair of reaction apertures  116  disposed on opposite sides of pilot pin  115 , each of which receives and retains therein a plunger shaped rod  118 . The outer ends  119  of the rods  118  protrude outwardly from the lower surface of upper die member  113 , while the inner ends  120  of rods  118  have coil springs  121  received thereon which resiliently urge rods  118  outwardly, such that the outer ends  119  of rods  118  serve to strip the stock strip  103  away from the exterior surface of the pilot pin  115 , and thereby permit the stock strip  103  to be shifted longitudinally into the next adjacent work station. 
         [0009]      FIGS. 13 and 14  illustrate yet another known prior art pilot assembly which includes a rectangular shaped block or base  111  that is mounted on to the lower surface  133  of the upper die member  113  using fasteners  134 . In addition, dowels  135  may be used to help locate and secure the base block  111  in dowel holes  136  in the upper die member  113  and/or dowel holes  137  in the base block  111 . The base block  111  includes a central aperture  114  in which a pilot pin  115  is retained, and two laterally offset reaction apertures  116  in which a pair of stripper assemblies are received and retained. A female punch tool  117  is positioned in the lower die member  122 , and closely receives the pilot pin  115  to precisely locate stock strip  103  in the associated work station. Each of the stripper assemblies comprises a plunger shaped rod  118  having an outer end  119  protruding outwardly from base block  111  toward the stock strip  103 , and an inner end  120  with a coil spring  121  received there over which resiliently urges the rods  118  outwardly on opposite sides of the pilot pin  115  and serve to strip the stock strip  103  from the exterior surface of the pilot pin  115  as the pilot pin and associated upper die member  113  are raised to a diverged condition relative to the lower die member  122 . 
         [0010]    Large manufacturers of formed metal parts, such as those which supply parts to automobile companies and the like, have an extensive inventory of metal forming dies and related metal handling machinery. Through the years, such companies have standardized several different styles and sizes of pilot punches and associated pins for use with their various dies, so as to maximize efficiencies when combining various tooling for a specific project. Similarly, the metal forming die industry generally has adopted such standard pilot punch and pin sizes and shapes to minimize the effort and expense of making, installing and maintaining the dies and related metal handling equipment. When a new die is designed and fabricated by a tool and die maker, the customer will often specify that the die maker use a specific shape and size of pilot punching pin, which is often one of several styles that are standard or non-custom, and are commercially readily available. Sometimes, the customer will actually provide to the die maker the pilot punch and pilot pins that it desires to be incorporated into a specific progressive metal forming die, or portion thereof. 
         [0011]    While such prior pilot assemblies have proven generally successful, they are rather expensive and time consuming to construct and install in an associated die set, such that further improvements and enhancements to the same, as well as metal forming dies generally, would be clearly advantageous, and are disclosed herein. 
       SUMMARY OF THE INVENTION 
       [0012]    One aspect of the present invention is a multi-station progressive metal forming die having at least two mutually converging and diverging die members between which an elongated stock strip is shifted longitudinally to form parts from the stock strip, along with an improved modular pilot assembly. The pilot assembly includes a generally cylindrically shaped pilot configured for operable support on one of the die members. The pilot has an outer end portion oriented toward the stock strip, an oppositely disposed inner end portion oriented away from the stock strip, and a medial portion disposed axially between the outer and inner end portions. The medial portion has an annular groove. The outer end portion has a generally tapered nose, with a circularly shaped innermost portion configured for close reception in a pilot hole in the stock strip, and a generally conically shaped outermost portion configured to engage the pilot hole in the stock strip and guide the same to a predetermined position in an associated die forming station. The inner end portion has a generally cylindrical shape, with a flat surface for engaging a surface of the one die member. A spring member having a generally hollow interior is received over the medial portion of the pilot. The spring member has an outer end oriented toward the stock strip, and an opposite inner end oriented away from the stock strip and positioned adjacent a surface on the pilot. A stripper has an outer collar portion with an outer end surface oriented toward the stock strip and a generally cylindrical first sidewall with a first outside diameter. The stripper also has an inner collar portion with an inner end surface oriented away from the stock strip with a generally cylindrical second sidewall having a second outside diameter which is less than the first outside diameter of the first sidewall of the outer collar portion to define an annularly shaped, radially oriented shoulder there between for engaging the outer end of the spring member. The stripper is received over the medial portion of the pilot. The outer collar portion of the stripper also has a first inner diameter and the inner collar portion has a second inner diameter which is less than the first inner diameter to define an annularly shaped, radially oriented inner shoulder there between. A retainer operably connected on the annular groove of the medial portion of the pilot maintains the stripper on the pilot assembly by engaging the inner shoulder of the stripper when the die members are diverged. 
         [0013]    Yet another aspect of the present invention is a modular pilot assembly for multi-station progressive metal forming dies having at least two mutually converging and diverging die members between which an elongate stock strip is shifted longitudinally to form parts from the stock strip. The pilot assembly includes a generally cylindrically shaped pilot configured for operable support on one of the die members. The pilot has an outer end portion oriented toward the stock strip, an oppositely disposed inner end portion oriented away from the stock strip, and a medial portion disposed axially between said outer and inner end portions. The medial portion has an annular groove. The outer end portion has a generally tapered nose, with a circularly shaped innermost portion configured for close reception in a pilot hole in the stock strip, and a generally conically shaped outermost portion configured to engage the pilot hole in the stock strip and guide the same to a predetermined position in an associated die forming station. The inner end portion has a generally cylindrical shape, with a flat surface for engaging a surface of the one die member. The assembly includes a spring member having a generally hollow interior that is received over the medial portion of the pilot, with an outer end oriented toward the stock strip, and an opposite inner end oriented away from the stock strip and positioned adjacent a surface on the pilot. The assembly also includes a stripper with an outer collar portion with an outer end surface oriented toward the stock strip and a generally cylindrical first sidewall with a first outside diameter, and an inner collar portion with an inner end surface oriented away from the stock strip. The inner collar portion has a generally cylindrical second sidewall with a second outside diameter which is less than the first outside diameter to define an annularly shaped, radially oriented shoulder there between for engaging the outer end of the spring member. The stripper is received over the medial portion of the pilot. The outer collar portion of the stripper has a first inner diameter and the inner collar portion has a second inner diameter which is less than said first inner diameter to define an annularly shaped, radially oriented inner shoulder there between. A retainer is operably connected on the annular groove of the medial portion of the pilot to maintain the stripper on the pilot assembly by engaging the inner shoulder of the stripper when the die members are diverged. 
         [0014]    Yet another aspect of the present invention is a method for making a multi-station progressive metal forming die having at least two mutually converging and diverging die members between which an elongate stock strip is shifted longitudinally to form parts from the stock strip, with the improvement of at least one modular pilot for precisely locating the stock strip in the die stations. The method includes forming a generally cylindrically shaped pilot for operable support on one of the die members with an outer end portion oriented toward the stock strip, an oppositely disposed inner end portion oriented away from the stock strip, and a medial portion disposed axially between the outer and inner end portions. The method includes forming an annular groove on the medial portion of the pilot. The method also includes forming the outer end portion with a generally tapered nose with a circularly shaped innermost portion configured for close reception in a pilot hole in the stock strip, and a generally conically shaped outermost portion configured to engage the pilot hole in the stock strip and guide the same to a predetermined position in an associated die forming station. The method includes forming the inner end portion with a generally cylindrical shape, with at least one flat surface for engaging a surface of the one die member. The method further includes selecting a spring member with a generally hollow interior. The method includes positioning the hollow interior of the spring member onto and over the medial portion of the pilot so that the outer end of the spring member is oriented toward the stock strip, and the opposite inner end is oriented away from the stock strip. The method includes forming a stripper with an outer collar portion with an outer end surface oriented toward the stock strip and a generally cylindrical first sidewall with a first outside diameter, an inner collar portion with an inner end surface oriented away from the stock strip with a generally cylindrical second sidewall with a second outside diameter which is less than the first outside diameter to define an annularly shaped, radially oriented shoulder there between for engaging the outer end of the spring member. The method includes forming the outer collar portion to have a first inner diameter and forming the inner collar portion to have a second inner diameter which is less than the first inner diameter to define an annularly shaped, radially oriented inner shoulder there between. The method includes positioning the stripper over the pilot. The method further includes selecting a retainer ring that fits securely onto the annular groove on the medial portion of the pilot and positioning the retainer ring on the annular groove to maintain the stripper on the pilot assembly by engaging the inner shoulder of the stripper when the die members are diverged. 
         [0015]    These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims, and appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a perspective view of a modular pilot assembly embodying the present invention, shown installed in a die set carrying a stock strip in which pilot holes have been formed. 
           [0017]      FIG. 2  is an exploded perspective view of the pilot assembly shown in  FIG. 1 . 
           [0018]      FIG. 3  is a perspective view of the pilot assembly in an assembled condition, taken from an outer end thereof. 
           [0019]      FIG. 3A  is a vertical cross-sectional view of the portion of the pilot assembly shown in 
           [0020]      FIG. 3  when the pilot assembly is in a position for installation on an upper die member. 
           [0021]      FIG. 4  is a top plan view of the pilot assembly as shown in the orientation of  FIG. 3 . 
           [0022]      FIG. 5  is a perspective cross-elevational view of the apertures in the window mount. 
           [0023]      FIG. 6  is a perspective view of the pilot assembly prior to installation on the upper die member. 
           [0024]      FIG. 7  is a perspective view of the pilot assembly partially installed on the die member. 
           [0025]      FIG. 8  is a perspective view of the pilot assembly installed on the die member. 
           [0026]      FIG. 9  is a partially schematic perspective view of a representative prior art die member shown in an open condition with a stock strip positioned along the various work stations in the die member. 
           [0027]      FIG. 10  is a partially schematic cross-sectional view of a prior art pilot. 
           [0028]      FIG. 11  is a partially schematic cross-sectional view of another prior art pilot. 
           [0029]      FIG. 12  is a partially schematic cross-sectional view of yet another prior art pilot. 
           [0030]      FIG. 13  is a perspective view of another prior art pilot. 
           [0031]      FIG. 14  is a perspective view of the prior art pilot shown in  FIG. 13 . 
           [0032]      FIG. 15  is a perspective view of another embodiment of a modular pilot assembly embodying the present invention. 
           [0033]      FIG. 16  is an exploded perspective view of the pilot assembly shown in  FIG. 15 . 
           [0034]      FIG. 17  is a vertical cross-sectional view of the pilot assembly of  FIG. 15  engaged with a stock strip prior to the die members converging. 
           [0035]      FIG. 18  is a vertical cross-sectional view of the pilot assembly of  FIG. 15  after the die members converge. 
           [0036]      FIG. 19  is a perspective view of the pilot assembly of  FIG. 15  shown installed on a die member. 
           [0037]      FIG. 20  is a vertical cross-sectional view of the pilot assembly shown in  FIG. 19 . 
           [0038]      FIG. 21  is a perspective view of the pilot assembly of  FIG. 15  shown installed on a die member using a window mount. 
           [0039]      FIG. 22  is a vertical cross-sectional view of the pilot assembly shown in  FIG. 21 . 
           [0040]      FIG. 23  is a perspective view of the pilot assembly of  FIG. 15  with another window mount. 
           [0041]      FIG. 24  is a vertical cross-sectional view of the pilot assembly shown in  FIG. 23 . 
           [0042]      FIG. 25  is a perspective view of another embodiment of a modular pilot assembly embodying the present invention. 
           [0043]      FIG. 26  is a vertical cross-sectional view of the pilot assembly shown in  FIG. 25 , shown installed on a die member. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0044]    For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal” and derivatives thereof shall relate to the invention as oriented in  FIGS. 1 ,  2 ,  3 A, and  4 - 26 . However, it is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
         [0045]    The reference numeral  1  ( FIGS. 1-4  and  6 - 8 ) generally designates a modular pilot assembly embodying an aspect of the present invention. As shown in  FIG. 1 , the pilot assembly  1  is particularly adapted for use in conjunction with a multi-station progressive metal forming die  2 , having at least two mutually converging and diverging die members  3  and  4 , between which an elongate stock strip  5  is shifted longitudinally to form parts from the stock strip. 
         [0046]    The modular pilot assembly  1  includes a generally cylindrically shaped pilot  10  operably supported on one of the die members  3 . The pilot includes an outer end portion  11  oriented toward the stock strip  5 , an oppositely disposed inner end portion  15  oriented away from the stock strip  5 , and a medial portion  13  disposed axially between said outer  11  and inner  15  end portions. The medial portion  13  has a generally cylindrical wall  54  with an annular groove  48 . Also, as illustrated in  FIGS. 2 and 3A , the medial portion  13  of the pilot  10  can be tapered to create a necked portion  52  that would have a smaller cross-sectional area. The outer end portion  11  of the pilot has a generally cylindrical shape where the medial portion  13  transitions to the outer end portion  11 . The outer end portion  11  then transitions to a generally tapered nose  28  with a generally frusto-conically shaped outermost portion  26 , with a tip  30 , configured to engage the pilot hole  6  in the stock strip  5  and guide the same to a predetermined position in an associated die forming station. The inner end portion  15  of the pilot has a generally cylindrical shape with a flat surface  20  for engaging a surface on the die member  3 . The inner end portion also has an inner facing surface  22  that can engage a surface for mounting the pilot  10  to the one die member  3  by way of a window  60  that is fastened to the one die member or by way of a fastener as discussed herein. A channel  24  may be formed within the inner end portion  15  for receiving a portion of the spring member  12 . 
         [0047]    A spring member  12  has an inner end surface  16  and an outer end surface  14  and a generally hollow interior  18 . The spring member is received over the medial portion  13  of the pilot  10 . The inner end surface  16  of the spring member  12  can be closely received within the channel  24  in the inner end portion  15  of the pilot  10  such that it abuts surface  25  in the channel  24 . 
         [0048]    The pilot assembly  1  includes a stripper  34  that has an outer collar  35  and an inner collar  37 . The outer collar  35  has an outer end surface  36  that can include a tapered edge  38  and an inner end surface  44 . The outer collar  35  has an outer diameter  51  and an inner diameter  53  as shown in  FIG. 2 . The inner collar  37  includes an outer diameter  55  and an inner diameter  57  as shown in  FIG. 3A . A generally annularly shaped, radially-oriented shoulder  40  on the stripper  34  engages the outer end portion  14  of spring  12  when the stripper  34  is installed on the pilot  10 . A generally annularly shaped, radially-oriented inner shoulder  50  is formed on the stripper  34  due to the difference between the inner diameter  57  of the inner collar  37  and the inner diameter  53  of the outer collar  35 . When the stripper  34  is installed in the pilot assembly  1 , the interior  46  of the stripper  34  will closely surround the pilot  10  as shown in  FIGS. 3 and 3A . 
         [0049]    A retainer ring  32  is received on the annular groove  48  on the medial portion  13  of the pilot  10 . The retainer ring  32  engages the inner shoulder  50  of the stripper  34  to retain the stripper  34  on the pilot  10  when the die members  3 ,  4  diverge. The outer wall  42  of the inner collar  37  of the pilot  34  may be closely received within the interior  18  of the spring member  12 . The retainer ring  32  may be any ring that can be closely received on the groove  48  and remain engaged in the groove during operation of the die  2 . For example, the ring  32  can be a steel C-ring. 
         [0050]    A window mount  60  may be used to help secure the pilot assembly  1  to the one die member  3 . The window mount has an aperture  62  ( FIG. 5 ) with a larger diameter portion  63  and a smaller diameter portion  64 , thus forming a shoulder  65  in the aperture  62 . The window mount includes a fastener opening  68  and can optionally include a dowel opening  66 . When the window mount  60  is used for installing the pilot assembly  1  on the one die member  3 , fastener apertures  70  are machined into the one die member  3 . Optionally, if dowels  75  are going to be used in the installation, dowel holes  72  are also machined into the one die member  3  as shown in  FIG. 6 . When the inner end surface  61  of the window mount  60  is placed against the lower surface  56  of the one die member  3 , the window mount can be used to secure the pilot assembly  1  to the one die member  3  as shown in  FIG. 7 . A fastener  74  is inserted through the fastener opening  68  in the window mount  60  and secured into the fastener opening  70  in the one die member  3 . Optionally, a dowel  75  can be inserted to help locate the window mount  60  on the one die member  3 . The dowel  75  is inserted into dowel opening  66  on the window mount  60  and into dowel opening  72  on the one die member  3  as shown in  FIGS. 7 and 8 . 
         [0051]    The term “die member,” as used herein, refers to any portion of a metal forming die or die set, including, but not limited to, an upper die member or a die shoe, a lower die member or a die shoe, and all other die components, whether stationary or reciprocating, including a reciprocating pressure pad, or the like. In the illustrated example, the pilot assembly  1  is shown mounted in a reciprocating upper die pad  3  located above a lower stationary die shoe  4 . However, as will be appreciated by those skilled in the art, pilot assembly  1  can be mounted in other types of die members and/or components in a variety of different positions and orientations, as necessary to precisely locate the stock strip  5  in the various workstations  102  of a metal forming die  100 . 
         [0052]    The illustrated pilot  10  has a one-piece construction formed from a solid bar of rigid material, such as metal or the like. Preferably, all machining operations on the solid bar of rigid material are made during a single machine setup, so as to achieve greater accuracy and consistency of the pilot  10 , as well as reduced manufacturing costs. In addition, the illustrated stripper  34  has a one-piece construction formed from a solid bar of rigid material, such as metal or the like. Again, preferably all machine operations on the solid bar rigid material are made during a single machine setup, so as to achieve greater accuracy and consistency of the stripper  34  as well as reduce manufacturing costs. 
         [0053]    As best illustrated in  FIGS. 1-3A , the outer end portion  11  of the pilot  10  has a relatively bullet-like profile, with a tapered nose  28  that ends to a relatively small, circular flat tip  30 . However, a wide variety of differently sized and shaped outer end portions  11  of pilot  10  can be used in accordance with the desires of the die maker and/or die user. 
         [0054]    In addition, the modular pilot assembly  1  can be used with different sized window mounts  60 . The thickness and shape of the window mount  60  can be changed. The illustrated window mount  60  has a one-piece construction formed from a solid bar of rigid material, such as metal or the like. In addition, the machining to create surfaces to secure the pilot assembly  1  to the die member  3  using a window mount  60  may be modified. For example, the die member  3  may also be machined to closely receive a portion of the pilot  10 . 
         [0055]    The illustrated spring member  12  comprises a conventional closed coil spring, which may have partially flattened or ground ends  14 ,  16  to more securely abut a surface  25  on the pilot  10  and the surface  40  on the stripper  34 . 
         [0056]    The illustrated fastener  74  comprises a conventional socket head cap bolt having a tool engaging socket  76  in the outer face of the fastener  74 , and a threaded shank portion  71 . The threaded shank portion  71  can include a self-locking nylon patch  176  (see  FIG. 20 ) which prevents fastener  74  from inadvertently loosening from its tightened condition in die member  3  and window mount  60 . However, the fastener may be any fastener, including but not limited to a bolt or screw. The inner surface  73  of the head of the fastener  74  may abut a shoulder in the fastener aperture  68  of window mount  60 . As illustrated, the threaded fastener aperture  70  in the die  3  is designed to receive a portion or all of the threaded shank  71  of the fastener  74  depending upon the depth of the shoulder in the fastener aperture  60  of the window mount  60  and whether there is a threading in the fastener aperture  68 . Also, as discussed below, the inner surface  73  of the head of the fastener  74  may be used to secure the pilot assembly  1  directly to the one die member  3  without the use of a window mount. In addition, a washer may be used with the fastener  74 . 
         [0057]    With reference to  FIGS. 6-8 , the assembled pilot assembly  1  is quickly and easily installed in the illustrated upper die pad  3  in the following manner. Once the assembled pilot  1  is placed in the appropriate spot on the upper die member  3 , the window mount  60  is placed over the pilot  10  so that the inner end surface  61  of the window mount  60  abuts the lower surface  56  of the one die member  3  (see  FIG. 6 ). The inner end portion  15  of the pilot  10  fits closely within the aperture  62  ( FIG. 5 ) of the window mount  60 . As illustrated in  FIGS. 1 ,  7 , and  8 , at least a portion of the stripper  34  extends beyond the outer end surface  67  of the window mount  60 . One or more fasteners  74  are used to secure the window mount  60  to the die  3 . Optionally, one or more dowels  75  can be used to help locate the window mount  60  on the lower surface  56  of the die  3  as described above. 
         [0058]      FIGS. 15-24  illustrate another embodiment of a pilot assembly  78  and various ways of mounting that pilot assembly  78  to the one die member  3 . The pilot assembly  78  includes a pilot  79  with an inner end portion  81 , a medial portion  82 , and an outer end portion  83 . The outer end portion  83  includes a tapered nose  91  with a generally circular tip  90 . The medial portion  82  (shown in  FIGS. 16-18 ) includes a generally annular groove  95 . The medial portion  82  can include a necked portion  96 , with a smaller cross-sectional area, where the medial portion  82  tapers from the groove  95  to the neck  96  and from the outer end portion  97  of the medial portion  82  to the neck  96 . The tapered design on the medial portion  82  allows the stripper  84  to tip and not bind on the pilot  79 . The inner end portion  81  has an outer diameter  81   d.  A generally circular stud  80  can extend inwardly from the inner end portion  81 . The stud  80  has an outer diameter  80   d  that is less than the outer diameter  81   d  of the inner end portion  81 , thus forming an annularly shaped, radially-oriented shoulder  92 . The inner end surface  93  of the inner end portion  81  of the pilot  79  also forms an annularly shaped, radially-oriented shoulder between the outside diameter  81   d  of the inner end portion  81  and the outside diameter  97   d  of the outer end portion  97  of the medial portion  82  of the pilot  79 . 
         [0059]    A spring member  87 , with an inner end  88  and an outer end  89  is received over the pilot  79 . The inner end  88  of the spring member  87  abuts surface  93  of the pilot  79 . 
         [0060]    The stripper  84  has an outer end portion  85  that may include a tapered portion  86 . As discussed above, the stripper includes an annularly shaped, radially-oriented outer shoulder  99  for engaging the outer end  89  of the spring member  87  and a generally annularly shaped, radially-oriented inner shoulder  98  for engaging the retainer ring  94  when the retainer ring  94  is installed in the annular groove  95  and the die members are diverged as shown in  FIG. 17 . When the die members start to converge, as shown by the arrows in  FIG. 17 , the spring member  87  becomes compressed as shown in  FIG. 18 . When the spring member is compressed, the inner shoulder  98  of the stripper  84  no longer engages the retainer ring  94  and the stock strip  5  closely fits onto the cylindrical portion of the pilot  79  where the outer end portion  83  transitions to the medial portion  82 . 
         [0061]    As illustrated in  FIGS. 19 and 20 , the pilot assembly  78  can be installed onto the one die member  3 . An aperture  150  is machined onto the one die member  3  for receiving the pilot assembly  78 . The aperture  150  has a smaller diameter portion  151  to closely receive the stud portion  80  of the pilot assembly  78 . In addition, the aperture  150  has a larger diameter portion  152  that closely receives the inner end portion  81  of the pilot assembly  78 . Aperture  150  also includes space  167  for receiving the pilot assembly  78  as well as space  163  for receiving a retainer  172  with the associated fasteners  170 . The aperture  150  includes a space  163  that is generally larger, but closely shaped to, the retainer  172  in the area of the fasteners  170 . Threaded fastener openings  153  are machined into the one die member  3 . 
         [0062]    The retainer  172  has fastener apertures  174  and a pilot aperture  173 . Threaded fasteners  170  are used to secure the retainer ring  172  and the pilot assembly  78  to the one die member  3 . The fasteners  70  have threaded shanks and can optionally include a self-locking nylon patch  176  as described above. As illustrated in  FIG. 20  when the pilot assembly  78  is secured to the upper die member  3  utilizing the retainer  172  and associated fasteners  170 , the shoulder  92  on the pilot assembly  78  abuts a surface  180  on the die member  3 , while the surface  93  of the pilot assembly  78  abuts a surface on the retainer  172  to press fit the pilot assembly  78  into the one die member  3 . 
         [0063]    Yet another way of securing the pilot assembly  78  is shown in  FIGS. 21 and 22 . An aperture  210  is machined into the one die member  3  to include a generally cylindrical wall  222  that closely receives the outer wall of stud  80 . In addition, the aperture  210  can include a smaller diameter opening  225  so that a shoulder  202  is created within upper die member  3 . The length of the stud  80  determines whether or not it touches the shoulder  202 . The shoulder  92  on the inner end portion  81  of the pilot  79  is received on the lower surface  56  of the one die member  3 . A window mount  220  has an aperture  212  with a larger diameter opening  216  and a smaller diameter opening  214 . The smaller diameter opening  214  closely receives, but does not restrict movement of the spring member  87 . The larger diameter opening  216  closely receives the inner end portion  81  of the pilot  79  such that the shoulder  93  of the inner end portion  81  abuts a shoulder  218  on the window mount  220 . As illustrated in  FIG. 21  a fastener  216  can be inserted through a fastener opening  218  in window mount  220  and secured in the one die member  3  in order to secure the window mount  220  and the associated pilot assembly  78  to the one die member  3 . 
         [0064]    The pilot assembly  78  may also be secured using a different style window mount  238  ( FIGS. 23-24 ) that contains an aperture  252  for receiving the pilot assembly  78  and an aperture  254  for receiving the fastener  236 . The aperture  252  for securing the pilot includes a smaller diameter aperture  255  and a larger diameter aperture  256 . The larger diameter aperture  256  is shaped to closely receive the inner end portion  81  of the pilot  79 . The smaller diameter portion  255  is designed to receive the medial portion  82  of the pilot  79  and the spring member  87 , without restricting movement of the spring member  87 . The inner end surface  246  of the window mount  238  should be generally flush with the shoulder  92  of the inner end portion  81  of the pilot  79  such that the inner end portion  246  and the shoulder  92  can abut the lower surface  56  of the one die member  3  when the pilot assembly  78  is installed on to the one die member  3 . An aperture for the stud  80  and a threaded aperture for the fastener  236  are machined into the upper die member  3  (not shown in  FIGS. 23 and 24 ) to facilitate installation of the pilot assembly  78  and window mount  238 . 
         [0065]    Another illustrated embodiment of a pilot assembly  300 , shown in  FIGS. 25 and 26 , includes a pilot  301  with an inner end portion  270 , an outer end portion  271 , and a medial portion  272 . The pilot  301  includes a stud portion  270  extending from the inner end portion  272 . The outer end portion  271  includes a tapered portion  260  and that extends to a rounded point  261 . A stripper  274  includes an outer end surface  278  with a tapered portion  276 . A spring member  262  includes an inner end portion  264  and an outer end portion  263 . The inner end portion  264  of the spring member  262  abuts surface  275  of the inner end portion  272  of pilot  301 . The stripper  274  includes an inner shoulder  283  that abuts the retainer ring  280  when the retainer ring  280  is retained on groove  282  on the medial portion  273  of the pilot  301  in the same manner as described above. 
         [0066]    An aperture  290  having a larger diameter opening  294  and a smaller diameter opening  292  is formed in the one die member  3 . The smaller diameter opening  292  is designed to closely engage the outer diameter of the stud  270 . The smaller diameter opening  294  is designed to closely receive the outer diameter of the inner end portion  272 . As shown in  FIG. 26 , the pilot assembly  300  is secured via fastener  266  to upper die member  3  by installation of the fastener  266  into a threaded fastener aperture  282  in the one die member  3 . 
         [0067]    A washer  268  may be used with the threaded fastener  266  to secure the pilot assembly  300  to the one die member  3 . As shown in  FIG. 26 , when the die members diverge, the stock strip  5  moves inwardly up the upper end portion  271  and the opening  6  in the stock strip is closely received on the pilot  301 . Also, as shown in  FIG. 26 , when the spring member  262  becomes compressed, the retainer ring  280  moves away from the shoulder  283  in the stripper  274 . 
         [0068]    The pilot assemblies  1 ,  78 , and  300  may be readily removed from die member  3  by simply reversing the sequence of the installation steps described above. 
         [0069]      FIG. 1  illustrates the operation of pilot assembly  1 . The upper die member  3  with pilot assembly  1  mounted therein is positioned to converge against the stock strip  5  that is supported on the upper surface  58  of the lower die member  4 . In this position, the stripper  34  is fully extended, and has yet to abut against the upper surface of the stock strip  5 . When the die members  3 ,  4  begin to converge, the tapered nose  28  of the pilot  10  is received through the most closely aligned one of the pilot holes  6  in stock strip  5  and into the female pilot portion  9  in the bottom or lower die member  4 . Next, the upper die pad  3  converges or closes completely against the stock strip  5  and lower die member  4  supporting the same, such that the abutting contact between the stripper  34  and the upper surface of the stock strip  5  overcome the biasing force of pretensed spring member  12 , further compressing spring member  12 , while shifting and/or retracting the stripper  34  back toward the interior of the outer end portion  11  of pilot  10 . The tip  30 , tapered nose  28 , and most if not all of the remaining generally cylindrical portion of the outer end portion  11  of the pilot  10  is thus received in the aligned pilot hole  6  in stock strip  5  and the female pilot portion  9  in the bottom die member  4 . The metal forming operation in the associated die work station is then completed with the pilot assembly  1  such that the stock strip  5  is precisely located and securely held in place during formation and further processing of stock strip  5 . As the upper die member  3  diverges or moves away from the stock strip  5  and the lower die member  4 , the resilient force generated by spring member  12 , urges the stripper  34  back outwardly toward and abuttingly against the stock strip  5  and separates or strips the stock strip  5  from the pilot  10 , such that the stock strip  5  can then be quickly shifted longitudinally to the next work station for further processing. 
         [0070]    The pilot assemblies  78  and  300  operate in a similar manner as shown in  FIGS. 17 ,  18 ,  25 , and  26 . 
         [0071]    As will be appreciated by those skilled in the art, pilot assemblies  1 ,  78 , and  300  can be provided in a wide variety of different sizes to accommodate many different metal forming die applications. The all-in-one, modular construction of pilot assemblies not only provides a self-contained stock stripper that uses only one spring, but can be quickly and easily installed in a die member using simple machining techniques, a window mount and/or one or more mounting screws. 
         [0072]    Pilot assemblies  1 ,  78 , and  300  have an uncomplicated construction with relatively few components and are therefore quite durable and economical to manufacture. The mounting screw(s) and optional window mount attachment of the pilot assemblies to an associated die member provides quick and easy installation and removal of the pilot assemblies. The spring member and assembly are backed up or axially supported by the die member itself for greater strength and convenience. Pilot assemblies  1 ,  78 , and  300  positively separate the stock strip from the die during operation of the metal forming die, and provide a very compact, low profile shape that can be used at various locations and orientations on the various die members. The installation of the pilot assemblies can be achieved with simple machining, so as to reduce installation time and cost. The shape of the assemblies can be configured, so as to accommodate many different applications and users. 
         [0073]    In the foregoing description, it will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed herein. Such modifications are to be considered as included in the following claims, unless these claims by their language expressly state otherwise.