Abstract:
A machine, tooling and method for cold forming complex metal parts such as a banjo style hose fitting starting with a near net shape volume of wire and continuing with multiple forging blows and an intermediate rotation of the blank to produce a hose coupling shell end, a transition neck, a large counterbored annular coupling body and a perpendicular alignment tang.

Description:
The invention relates to cold-forming complex metal parts and, in particular, seamless hollow parts having features developed on different axes. 
     BACKGROUND OF THE INVENTION 
     Multi-station or progressive cold-forging machines are well known. Up to now, as far as known, the versatility of such machines has been limited, inter alia, by the number of stations available in a given machine. When a part can be cold-formed from a metal blank that is at or near the volume of the finished part, sometimes referred to as net shape or near net shape, considerable savings in material cost, machine time, and labor can be realized. There thus exists a need for machines of the nature described with improved versatility and for new methodology to advance the art of cold forming complex metal parts. 
     SUMMARY OF THE INVENTION 
     The invention provides a methodology of operating a progressive forming machine that produces a part with multiple features formed on multiple axes perpendicular to one another. The invention affords, as another aspect of the invention, a novel hose fitting that includes a counterbored connector body and an integral alignment tang. In the forming process of the invention the tang is caused to extend well beyond the plane of a mounting face of the connector body to thereby securely and reliably locate and orient the fitting on a brake caliper or like housing or manifold. The inventive method produces the brake hose fitting in a condition that is ready for assembly with the hose without secondary machining operations except for drilling of a small fluid passage. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a banjo style brake hose fitting made by the process of the invention; 
         FIGS. 2A and 2B  show the brake hose fitting in successive stages of cold forming; 
         FIGS. 3A ,  3 B and  3 C show progressive forming steps in the environment of a multi-station forging machine used to produce the brake hose fitting; 
         FIG. 4  is a somewhat diagrammatic fragmentary perspective view of a high force lever and gas spring system for biasing the dies at selected forming stations; and 
         FIG. 5  is a schematic drawing of a part rotator. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  illustrates a cold-formed metal part  10 , typically made of steel, in the form of a brake hose fitting. The particular form of fitting  10  is of the banjo style, a description derived from its similar appearance to the musical instrument. The part  10  is preferably formed of a suitable steel such as spheroidalized annealed steel. A description of the process, machine, and tooling used to make the part  10  follows. 
     In  FIGS. 2A ,  2 B and  3 A,  3 B, and  3 C, the preforms of the part  10  are identified by the numeral  10  with a sequential letter of the alphabet as a suffix corresponding to its stage in the progressive forming steps. 
     In the following description, an intermediate part may be designated just by the numeral  10  such as when the part is in a transitional period between forming stages.  FIGS. 2A and 2B  provide partial sectional views of the part preform while  FIGS. 3A ,  3 B, and  3 C provide views of the part preforms within successive stations of a progressive cold-forming or forging machine  11 . The machine  11  is of generally conventional construction except that it has an increased number of forming stations. In the illustrated case, the number of forming stations is nine, although in the disclosed process, one of the stations is dedicated to manipulating the part as opposed to contributing a forming step at such station. This explains why the number of stages shown in  FIGS. 2A and 2B  is different than the number of stations seen in  FIGS. 3A ,  3 B, and  3 C. 
     Wire stock  12  ( FIG. 3A ) typically fed from a supply coil is cut to a precise length at a cutoff station  13  to provide a starting piece  10   a  for the part  10 . From this cutoff station  13 , the part  10  is sequentially moved to subsequent stations, where it is progressively formed or, in one case, rotated, by a mechanical transfer (not shown) of generally conventional design. A die breast or block is indicated at  14  and a reciprocating slide or ram is indicated at  16 . 
     The forming stations of the machine  11  are identified by the numerals  21 - 29  inclusive. In the first forming station  21 , the part  10   b  is coned or upset at one end  31  to locally increase its diameter and open extruded at the other end  32  to decrease its diameter by tools  33 ,  34 , and  35  on the slide  16  and die block  14 , respectively. The part  10  is transferred to the second forming station  22  where, in the next blow of the slide  16 , it is back extruded at the end  31  by a tool  36  on the slide  16  to create a cylindrical shell and further open extruded at the other end  32  with a tool  38  carried on the die block  14  to create a further reduction in diameter. 
     In the third forming station  23 , the part  10   d  is double upset or coned at its mid-length by tools  41 ,  42 . The tool  42 , carried on the die block  14 , comprises segmented inserts  43 . These segmented inserts  43  are arcuate segments that contract radially inwardly against the part  10  when the punch tool  41  first strikes the end face of the segments  43 . The segments  43  work in a tapered bore of a die case  44 . The die case  44  is strongly biased to a forward position towards the slide  16  by a forked lever  46  that, in turn, is pushed by a large high pressure nitrogen gas spring  47  ( FIG. 4 ). In the disclosed arrangement, upper ends of the forked lever  46  operate on the die case  44  through push rods  48 . The segment inserts  43  establish the position and geometry of the upset at the mid-length of the part  10   d . The spring biased lever  46  allows the die case  44  to yield axially rearwardly to the force of the slide  16  during the actual upset action at the forward end of the slide stroke while maintaining the segments closed around the part  10   d  to properly shape it. When the slide  16  retracts, the segment inserts  43  open to allow release of the upset mid-section and subsequent transfer of the part from this station  23 . 
     In  FIGS. 3A ,  3 B, and  3 C tines  51 ,  52  of the forked lever  46  are offset from one another, the one on the right being retracted and the one on the left being extended. This offset between the tines  51 ,  52  is for illustrative purposes only in these figures to simply show the typical movement of the lever and it will be understood that the tines in actuality are working in concert and are at the same relative position to the die plate or block  14 . 
     The part  10  is advanced to the fourth station  24  where its mid-section is again double upset in tooling  53 ,  54  in a die case to develop a spherical or ball-shaped mid-section. The die side tooling  53  comprises segmented inserts operated like that just described in connection with the tooling inserts  43  at the previous station  23 . As before, a gas spring powered lever  46  biases a die case  56  through push rods  48 . 
     Next, the part  10  is transferred to the fifth station  25  where it is received in a blank rotator  58 . The blank rotator  58  occupies the space normally taken up by a regular die case at this station  25 . The blank rotator  58  is schematically shown in  FIG. 5  in a perspective view. No forming of the part  10  occurs in this station  58  when the slide  16  comes forward in the next stroke. When the slide retracts, the part rotator  58  rotates the part  10  90° from its original orientation where its longitudinal axis is horizontal and parallel to slide motion to an orientation where its longitudinal axis is vertical with the hollow or shell end  31  up and the pin or tang end  32  down. The rotation of the part  10  is about a horizontal axis  60  of a trunnion-like structure  59 . This rotation is synchronized with the die kick-out motion at the station  25 . 
     In its progress from this station  25  through subsequent stations  26 - 29  inclusive, the part  10  remains in the orientation with longitudinal axis in an upright or vertical position, i.e. perpendicular to the motion of the slide  16  and to the plane of the work stations  21 - 29 . However, for purposes of illustrating the process in a clear, simplified single drawing, the part  10  in  FIGS. 3B and 3C  is shown in the stations  26 - 29  beyond the rotator station  25  in what appears to be a horizontal orientation. It should be understood, therefore, in actuality, the part  10  is vertical in the stations with the shell end  31  up. Of course, the tooling is oriented so that it compliments the respective progressive shapes produced at each of the respective stations. 
     In the sixth forming station, the spherical mid-section of the part  10   f  is flattened and dimpled or recessed by tooling  61 ,  62  on the punch and die sides, respectively. 
     At the seventh station  27 , the flattened mid-section of the part  10   g  is pierced to form a circular bore  63  by removing a round slug or coupon  64  and a pin or tang  68  comprising the part end  32  is bent laterally off the longitudinal axis of the part. A gas spring  47  and forked lever  46  like that described in connection with the third station  23 , is used to hold the die tooling  66  against the punch tooling  67  during the forming of the part  10   g  at this station. The bending action on the tang designated  68  is produced by an anvil-like tool  69  rigidly fixed to the die plate. The tooling and timing of the actuation of the tooling is such that the piercing of the bore  63  occurs before the tang  68  is bent. This isolates the forces of these different operations from each other so as to achieve consistent forming action in both the formation of the bore  63  and the bending action on the tank  68 . 
     The part  10   h  in the eighth station  28 , backed up by tooling  71  on the die side, has its bore broached or sheared by punch tooling  70  to gather material from the wall area forming the previous bore  63  at one end of this bore and in effect forming a counterbore  72  with an end wall  74 . 
     At the last or ninth station  29 , the pin or tang  68  is bent on an anvil tool  79  fixed on the die plate  14  so that the tang  68  extends perpendicularly to the longitudinal axis of the part  10   i . Ideally, the tang  68  extends laterally outward of the plane of the adjacent side of the circular body surrounding the bore  72  so that it can reliably be received in a hole, slot or other formation to align the fitting  10  to the body of a brake caliper or cylinder. Also at this station, after bending the tang  68 , the part  10   i  is re-pierced through the counterbore end wall formed in the preceding station to complete the finish shape of the counterbore by cutting an annular slug or coupon  76  from the part with punch tooling  77  to make a precise hole or bore  78  at the end wall  74 . Like the tooling action that occurred in the seventh station, tools  81  on the die plate or block  14  are forwardly biased by a gas spring  47  operating through a forked lever  46  as previously described. The biasing force assures that the punch and die tools,  77 ,  81  work like complementary clamshell halves to precisely hold the part  10   i  during these forming operations. 
     The part  10  is finished as far as cold-forming is concerned at the last station  29   i . As seen in  FIG. 2  in the last stage, as well as in  FIG. 1 , a part  10  produced by the disclosed methodology is of complex shape. The part  10 , a banjo style brake hose fitting, includes a hollow cylindrical shell  86 , a cylindrical solid neck area  87 , a circular body  88  having a large counterbore  72  on an axis perpendicular to the shell and neck and being open at two opposite faces  89 ,  90 , and a round tang  68  extending from the longitudinal axis at a right angle for distance sufficient to project beyond the plane of a face  89  of the circular body or ring  88 . A central hole (not shown) is drilled through the neck  87  to provide fluid communication from a hose end assembled in the shell  86  and the counterbore  72 . The shell  86  may be crimped over the hose end in a customary manner to lock it in position and form a fluid tight seal therewith. A bolt, not shown, is assembled into the counterbore  72  from the side of the face  90  and threaded into the body to which the fitting couples the hose. 
     It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.