Patent Document

This application claims priority to Applicant&#39;s U.S. Provisional Patent Appl. No. 60/924,328 titled “ELECTRICAL OUTPUT GENERATING DEVICES AND DRIVEN ELECTRICAL DEVICES, AND METHODS OF MAKING AND USING THE SAME” filed May 9, 2007, U.S. Provisional Patent Appl. No. 61/064,162 titled “ELECTRICAL OUTPUT GENERATING DEVICES AND DRIVEN ELECTRICAL DEVICES, AND METHODS OF MAKING AND USING THE SAME” filed Feb. 20, 2008, and to U.S. Provisional Patent Appl. No. 61/064,161 titled “LAMINATE ROTOR OR STATOR ELEMENTS FOR ELECTRICAL OUTPUT GENERATING DEVICES AND DRIVEN ELECTRICAL DEVICES, AND METHODS OF MAKING AND USING SUCH ELEMENTS AND DEVICES” filed Feb. 20, 2008. This application has a common filing date with U.S. patent application Ser. No. 12/149,931, now U.S. Pat. No. 7,800,275 titled “ELECTRICAL DEVICES USING ELECTROMAGNETIC ROTORS” U.S. patent application Ser. No. 12/149,935, now U.S. Pat. No. 7,876,019 titled “ELECTRICAL DEVICES WITH REDUCED FLUX LEAKAGE USING PERMANENT MAGNET COMPONENTS” U.S. patent application Ser. No. 12/149,934, now U.S. Pat. No. 7,868,511 titled “ELECTRICAL DEVICES USING DISK AND NON-DISK SHAPED ROTORS”, and U.S. patent application Ser. No. 12/149,936, now U.S. Patent Application Publication No. 2009/020,6693 titled “ELECTRICAL OUTPUT GENERATING DEVICES AND DRIVEN ELECTRICAL DEVICES HAVING TAPE WOUND CORE LAMINATE ROTOR OR STATOR ELEMENTS, AND METHODS OF MAKING AND USE THEREOF”, the entirety of each of which is hereby incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     Aspects of the present invention relate to the field of manufactured powdered metal parts, and, in particular, to devices and methods for affixing powdered metal parts to other mechanical parts, and methods of making and use thereof. 
     2. Background of the Technology 
     The ability to construct devices from powdered metal materials has many advantages. Powdered metal parts can be molded precisely, allowing strict tolerance compliance in using the parts in assemblies. The molding process allows design of complex parts because minimal or no additional machining is required to bring the parts within tolerance. 
     Most powdered metal parts are cured through a sintering process which includes heating of the powdered metal part to a temperature below melting but high enough to foster adherence of the powdered metal particles to one another. Sintering is generally used to increase the strength of a part, but sintering may aggravate the magnetic properties of a powdered metal part, making the process undesirable for certain applications, including for use as magnetic flux concentrators in electric motors. 
     SUMMARY OF THE INVENTION 
     Particular variations of methods and devices for joining powdered metal parts described in accordance with aspects of the present application may satisfy one or more of the above identified needs, as well as others, by disclosing powdered metal parts and fasteners, methods of making and use thereof, that, among other things, permit the attachment of powdered metal parts to other parts of dissimilar material without disruption of the magnetic flux properties of the powdered metal parts. With these features and others, aspects of the present invention thereby provide other advantages, such as enabling more efficient manufacturing of joined parts. 
     In a first exemplary aspect of the present invention, a method of manufacture may begin by inserting a pre-machined mechanical part into a forming apparatus. Powdered metal fasteners or other attachment related mechanisms may be inserted into the pre-machined part by hand or directly by a fastener insert tool. A forming tool may be used to create a cavity or other features into or onto which a powdered metal is flowed. The powdered metal may then be mechanically pressed under high pressure to join a powdered metal part to a mechanical part via the fastener or other attachment related mechanism. 
     In another variation of the present invention, a powdered metal part is joined to a pre-machined mechanical part by direct molding with no fastening device or mechanism. 
     Other aspects of the present invention relate to various fastening devices for joining a powdered metal part to a pre-machined mechanical part through a pressing process. 
     Additional advantages and novel features relating to devices and methods for affixing powdered metal parts to other mechanical parts, and methods of making and use thereof, will be set forth in part in the description that follows, and in part will become more apparent to those skilled in the art upon examination of the following or upon learning by practice of aspects of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       In the drawings: 
         FIG. 1  illustrates an exemplary forming apparatus and affixing devices for forming and joining a powdered metal part to a mechanical part in accordance with aspects of the present invention; 
         FIG. 2  illustrates an exemplary cutting device for forming the geometry of a mechanical part for accepting powdered metal fasteners in accordance with aspects of the present invention; 
         FIG. 3  illustrates an exemplary install tool for placing powdered metal fasteners in position for affixing a powdered metal part to a mechanical part in accordance with aspects of the present invention; 
         FIG. 4  shows the exemplary install tool of  FIG. 3  after rolling the retention lip of the mechanical part in accordance with aspects of the present invention; 
         FIG. 5  is an exemplary illustration of powdered metal flowing down and compacting into the cavities of an exemplary mechanical part in accordance with aspects of the present invention; 
         FIG. 6  shows the impact of the powdered metal compaction on an exemplary powdered metal fastener in accordance with aspects of the present invention; 
         FIG. 7  illustrates the uninhibited effect of an exemplary powdered metal fastener on the magnetic flux of a powdered metal part in accordance with aspects of the present invention; 
         FIG. 8  illustrates an exemplary application of the methods and devices described herein in accordance with aspects of the present invention; 
         FIG. 9  illustrates the geometry of an exemplary powdered metal fastener in accordance with aspects of the present invention; 
         FIG. 10  shows an exemplary geometry for a machined pocket or cavity in a mechanical part for directly affixing a powdered metal part thereto without the use of fasteners in accordance with aspects of the present invention; 
         FIG. 11  illustrates the geometry of exemplary fasteners that may be used when machining or metal forming of the mechanical part prohibits the geometry shown in  FIG. 10  in accordance with aspects of the present invention; 
         FIG. 12  shows an exemplary wedge fastener in accordance with aspects of the present invention; 
         FIGS. 13A and 13B  illustrate exemplary compression fit fasteners in accordance with aspects of the present invention; 
         FIGS. 14A ,  14 B and  14 C illustrate exemplary variations of a dove tail type fastener in accordance with aspects of the present invention; 
         FIGS. 15A and 15B  illustrate exemplary variations of fasteners in accordance with aspects of the present invention; and 
         FIGS. 16A and 16B  illustrate an exemplary variation of a powdered metal part bonded to a substrate in accordance with aspects of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Aspects of the present invention and its implementations are not limited to the specific components or assembly procedures disclosed herein. Many additional components and assembly procedures known in the art consistent with devices and methods for affixing powdered metal parts to other mechanical parts, and methods of making and use thereof will become apparent for use with particular aspects and implementations from this disclosure. Accordingly, for example, although devices and methods for joining powdered metal parts to mechanical parts for use in a magnetic environment, for example, are disclosed, such devices and/or methods, including implementing components, may comprise any suitable shape, size, style, type, model, version, measurement, concentration, material, quantity, and/or the like usable for such fastening devices and/or methods and implementing components, consistent with the intended operation of the devices. 
     Description of exemplary aspects and implementations of methods and devices for joining powdered metal parts will now be made with reference to the appended drawings. 
       FIG. 1  shows a sectional view of an exemplary forming apparatus  1  and fasteners  101 ,  102  for forming and joining a powdered metal part  10  to a mechanical part  20 . (Note: when the term fastener is referenced as  100  in sections of the specification, the feature refers to fasteners or fastening devices, in general, of the type illustrated in this application. Use of reference numbers other than  100 , for example  101  or  102 , for a fastener indicate a particular embodiment of a fastener or fastening device, rather than fasteners in general.) A mechanical part  20  is provided and set into the forming apparatus  1 , such as a powdered metal press. A form tool  30  may be provided that is configured to work in tandem with the mechanical press  40  to form the dimensional characteristics of the powdered metal part  10 . The form tool  30  may comprise a mold machined from carbide, for example. The mold may have side walls and a bottom surface, for example, to form a cavity for placement and support of the mechanical part  20 , prior to pressing. In another variation, the forming tool  30  may operate in tandem with a support boss  50 , as shown in  FIG. 1 , to provide for support and placement of the mechanical part  20  prior to pressing. 
     The mechanical part  20  may be made from any of a variety of suitable material, including steel or aluminum, for example, and may be pre-machined as required to facilitate the manufacturing process.  FIG. 1  illustrates two exemplary variations of the mechanical part  20  machined to receive a powdered metal fastener  101  or  102 . Powdered metal fasteners may be described herein, but any of a variety of fasteners may be used, including solid metal fasteners.  FIG. 1  illustrates a through-hole  21  that has been machined to receive a powdered metal fastener  101  inserted from the bottom and supported by a support boss  50 . The through-hole  21  may include any number of geometric features to enhance the joining and manufacturing processes, including tapering the upper portion of the through-hole  21 , for example, to provide a press fit of the fastener  101 , or shoulders  23  may be provided as a seat for the fastener during the pressing operation.  FIG. 1  also illustrates a fastener cavity  70 , machined into the mechanical part  20 , which may comprise a fastener seat  71 , rollover lip  73  and coining gap  75 , for example. 
       FIG. 2  illustrates an enlarged view of the fastener cavity  70  of  FIG. 1 . A special cutter  200  may be used to machine a fastener seat  71  to specific dimensions, in accordance with the type and size of a fastener to be used. The special cutter  200  may have a cutting flange  205  for milling a rollover lip  73  and associated coining gap  75 , for example. 
     A method of manufacture may begin by inserting the pre-machined mechanical part  20  into the forming apparatus  1 , as illustrated in  FIG. 1 . Powdered metal fasteners  100 , for example, may be inserted into the pre-machined part by hand or directly via a placement tool (not shown). The fasteners  100  may be inserted into each seat  71 , where the fasteners  100  may be held in place by an assembly adhesive, for example. The fasteners  100  may themselves be coated with assembly adhesive, or other surface treatments, to facilitate the bonding process. The assembly adhesive may hold the fastener in place prior to the pressing process, but the adhesive should not inhibit the free rotation or lateral movement of the fastener during the pressing process. 
     As shown in  FIG. 3 , a fastener install tool  300  may be configured to work with a particular fastener  100  and/or mechanical part  20 , for example. The fastener install tool  300  may be designed with a tapered interior gap  302  for protecting aspects of the fastener, including the tip. The gap  302  may comprise configurations specific to the dimensions and geometry of a particular fastener. For instance,  FIG. 3  shows a shoulder  304  and beveled surface  305  for properly seating the tip of the fastener in the fastener install tool without causing damage when the install tool yields a downward force while inserting the fastener  100  into the fastener cavity  70 . 
     The fastener install tool  300  exerts a downward force on the fastener  100  until the fastener  100  is seated in the fastener seat  71 . As the install tool pushes down on the fastener, as shown in  FIG. 3 , a flanged rim  310  on the install tool exerts a bending pressure on the rollover lip  73 , in a coining process. The geometry of the flanged rim  310  may be such that an inwardly sloped surface  312  meets the rollover lip  73  at a point  315 . As seen in  FIG. 4 , the downward force of the install tool, combined with the slope  312  of rim  310 , may cause the rollover lip  73  to yield inward. While the rollover lip  73  folds over in a coining process, the flanged rim  310  slides into the coining gap  75 . At this point, the fastener  100  fits snug in the fastener cavity  70 , but, by virtue of the geometry of the seat  71  and the head of the fastener  100 , the fastener may still twist or lean when subjected to pressure. 
       FIG. 5  illustrates another step in the process of affixing a powdered metal part  10  to the mechanical part  20 . With the fastener  100  in the cavity  70 , powdered metal  11  may be flowed downwardly, as shown in  FIG. 5 , into the cavity formed by the form tool  30  and the mechanical part  20 . 
       FIG. 6  illustrates the powdered metal  11  after it is compacted by a mechanical press under high pressure, such as 60,000 pounds per square inch (psi). Because of the geometry of the fastener  102 , such as the inclusion of a bulbous head, the fastener can yield to unequal forces exerted during the compacting process by twisting or tilting. The ability of the fastener to yield in this manner may permit complete compaction of the powdered metal material around the fastener and may protect the fastener from breaking. At the same time, as the pressure is exerted by the mechanical press on the powdered metal, the overhang of the rollover lip  73  creates a pocket  74  where the density of the packed powdered metal is lower than that of the packed powdered metal above the lip  73 . The higher density of the material above may cause the lip  73  to further fold over the material below in pocket  74 , causing the powdered metal in pocket  74  to further compress. The powdered metal above the folded lip  73  is thereby locked in place by the powdered metal at full density, or near full density, in pocket  74 . In this manner, a powdered metal part  10  is simultaneously formed and affixed to the mechanical part  20 . 
     The fold-over process of the lip  73 , as well as the density in pocket  74 , may be controlled to limit undue strain on the fastener  102 , for instance. Because powdered metal particles do not behave like a fluid, the amount of lip rollover is important because a properly designed rollover creates a “dovetail”, or reverse, taper effect, without compromising the compaction density of the powdered metal part. For example, the density of the powdered metal material in pocket  74  may be controlled by varying the thickness of the lip  73  during the machining of part  20 , or by adjusting the initial overhang of lip  73  through configuration of the fastener install tool  310 . Superior to simply packing the powdered metal into the pocket  74 , a properly yielding lip  73  may become part of the pressing fixture for that micro region, in effect increasing the compaction of the powdered metal below the lip  73  and adding to the tensile strength of the bonded powdered metal part  10 . Controlling the density may also be important in some applications for protecting the integrity of the fastener  102  during the pressing process. Too low of a density, for instance, could allow the lip  73  to fold completely over onto the fastener  102 , possibly shattering or adversely impacting the structural integrity of the pre-formed and pre-strengthened powdered metal fastener  102 . Once formed, the powdered metal fastener  102  may be magnetically invisible within the powdered metal part  10 , allowing uninhibited flow of magnetic flux, as shown in  FIG. 7 . 
       FIG. 8  shows one exemplary variation of a rotor portion  1000  of an electrical output generating device or driven electrical device for use in accordance with aspects of the present invention. Rotor portion  1000  includes an axial disk portion  1010 , having a flange portion  1020 . Attached to and extending from flange portion  1020  may be a plurality of rectangular or wedge shaped plates  1030 . Such plates  1030 , as shown in  FIG. 8 , may, for example, be affixed using powdered metal formed over one or more flux conducting fasteners or other fastening extensions attached to flange portion  1020 , or machined into the disc, as described above. 
     An exemplary process may include configuring the axial disk portion  1010  with flange  1020  using a special cutter to accept powdered metal fasteners in pre-machined cavities. The pre-machined axial disk portion  1010  with flange  1020  may then be placed into a forming tool, for example. Powdered metal fasteners may be provided in the machined cavities using the fastener install tool, which also may bend a machined lip around the fastener in a coining process. Powdered metal may then be flowed into the forming tool cavity, and a mechanical press used to apply high pressure to the powdered metal flowed around the powdered metal fasteners, as described above. The rollover process of the machined lip, in combination with the powdered metal fastener, may hold the powdered metal plates  1030  in place. The mechanical press may then be released, and the rotor portion  1000 , comprised of the powdered metal plates  1030  affixed to the axial disk  1010  with flange  1020 , may be removed, without sintering. In this manner, the flux signature of the powdered metal part is controlled and constant, and the magnetic properties of the powdered metal fastener in the powdered metal part become invisible to flux traveling therethrough. 
     An exemplary process is described above for manufacturing a powdered metal assembly for use in a magnetic flux application, but bonded powdered metal parts may be used in a variety of applications, including those which may require sintering. Moreover, the powdered metal parts described herein may be hardened using other methods known in the art, including a variety of alternative heat treatment methods, steam treatments or impregnation with adhesives. 
       FIG. 9  illustrates an exemplary variation of a powdered metal fastener  102  that may be used in the process described above. The fastener  102  has a radiused head portion  103  at a first end that allows for tilting of the fastener  102  once set in place. The head portion  103  has a large head surface area  104  for distributing extreme force that may be exerted during the pressing process. A tapered body member  105  extends axially from the head portion  103  and may include undercut barbs  106  along the outer circumference along the length of the body member  105  that are angled for maximum holding strength. The tapered body member  105  may include a pointed distal end  107  designed to further minimize and distribute any force applied in the axial direction of body member  105  by the pressing process or the fastener install tool. 
       FIG. 10  illustrates another variation of a mechanical part  20  machined with a fastenerless pocket  410 . The pocket  410  may be machined to include a wedged gap  402  and flange  403 . The bottom surface of pocket  410  cylindrically ramps up from the base  405  of the flange  403  to a peak  404  in the center of the pocket  410 . The peak  404  may be polished or coated with a material to enhance the flow of powdered metal toward the base  405  of the flange  403 . In this manner, as the mechanical press exerts enormous pressure on the powdered metal, the powdered metal simultaneously drives into the wedge gap  402  and slides off of the peak  404 . The pressure exerted in the wedge gap  402  causes the flange  403  to begin folding over. As this effect occurs, an undercut density shadow enhances the effect due to the lower density now underneath the flange  403  overhang. At the same time, the peak  403  drives the powdered metal material toward the base  405  of the flange  403 , causing the base  405  to displace radially outward, further enhancing the fold-over action of the pressing process. The enhanced fold-over may be desirable in this variation, as there may be no possibility of damaging a fastener. The fold-over provides the mechanism for holding the formed powdered metal part directly to the mechanical part  20  without the need for a fastener. 
     Further, some aspects of these devices give rise to difficulties with manufacturing. For example, the mechanical part  20  may be comprised of a material that is brittle if bent, such as aluminum. In the case where material properties or other factors prevent machining or metal forming on the co-molded mechanical part  20 , a fastener ideally matched to the powdered metal forming process may be installed with threads or barbs, for instance. 
       FIG. 11  illustrates an exemplary approach in which a fastening device  600  may engage a pre-machined bore  25  in the mechanical part  20 . The bore  25  could be simply a hole of fixed diameter and depth. Threads  614  may be provided on an interior surface of the bore  25  for receiving a threaded fastening device  600 , or the fastening device  600  may comprise directional barbs  616  for compression fitting into the bore  25 . The fastening device  600  may be installed by a fastener install tool or by hand. Once installed, a form tool will operate in tandem with the mechanical part  20  to form a cavity into which a powdered metal may flow. A mechanical press may then apply high pressure to bondform the powdered metal particles into a powdered metal part. 
     As further shown in  FIG. 11 , the fastening device  600  may be machined to include a flange  603 . The flange may be slightly bent radially inward to create a wedged gap  602  between the flange and an inner surface of the bore  25 . A peak  604  that cylindrically ramps up from the inner base  605  of the flange  603  is provided in the fastening device  600 . The peak  604  may be polished or coated with a material, such as uncured epoxy, which acts as a lubricant to enhance the flow of powdered metal toward the base  605  of the flange  603 . In this manner, as the mechanical press exerts enormous pressure on the powdered metal, the powdered metal simultaneously drives into the wedge gap  602  and slides off of the peak  604 . The pressure exerted in the wedge gap  602  causes the flange  603  to fold over further. As this occurs, the undercut density shadow increases, and the effect of the lower density underneath the flange  603  overhang enhances the fold over effect. At the same time, the peak  604  drives the powdered metal material toward the base  605  of the flange  603 , causing the base  605  to displace radially outward, further enhancing the fold-over action of the pressing process. This operation may enhance the compression fit of the fastening device  600 , due to the outward force applied against the walls of the bore  25 . In this manner, the flanges  603  may act as a clamp on the packed powdered metal part, holding it in place and preventing it from disengaging from the mechanical part  20 . 
     The fastening device  600  may be designed to completely fit into the bore  25 . As shown in  FIG. 11 , the top of the flange  603  is situated below the shoulders  27  of an upper surface  22  of the mechanical part  20 . Thus, the flux properties of the joined parts may be such that flux flows unimpeded over the top of the bore  25  through the powdered metal part. In this manner, the fastening device  600  may be comprised of almost any material, including titanium, copper or steel, for example. This configuration allows joining of a powdered metal part under high pressure to a mechanical part  20  that might have material properties that would otherwise prevent machining or direct co-molding, without losing the flux characteristics important in certain operating environments. 
       FIG. 12  shows another variation of a fastening device. A “drop in” wedge fastener  650  may allow for easier hand installation of the fasteners without requiring a multi-step machining process. The fastener  650  may be pre-assembled and comprise an outer cylinder  652 , for example, and a wedge  660 . The outer cylinder  652  includes an inner bore  651  that is tapered so as to have a larger diameter in a shoulder area  656  than the inner end surface  658 . The outer cylinder  652  further has an upper flange  653  that is bent radially inward over the upper surface of the wedge  660 . 
     The tapered cylindrical wedge  660  is compression fit into the bore  651 . The wedge has a lower surface  662  with diameter greater than the diameter of the inner end surface  658  and is tapered at a degree matching the taper of the outer cylinder  652 . The wedge has an upper surface with a central rounded peak  654  that ramps down to the inner base  655  of the flange  653 . Because the wedge  660  has a base of larger diameter in the upper direction, as shown in  FIG. 12 , the wedge does not completely slide down into the cylinder  652 . 
     The configuration of the “drop-in” wedge fastener  650  may permit the flange rollover process described above to effectively bond a powdered metal part to the mechanical part. The wedge fastener  650  may also be made from material matched to the powdered metal properties for heat treatment so that it hardens and strengthens as well during a heat treatment process. In this manner, the wedge fastener  650  may be comprised of a more malleable material to facilitate the pressing process. 
     The pre-assembled “drop-in” fastener  650  may then be inserted into the pre-machined bore  25  of a mechanical part  20 , for example. The force from the pressing operation drives the wedge  660  to a selected depth, causing a high magnitude press fit of the cylinder  652  against the bore  25 . The flange gap  657  operates in tandem with peak  654  to produce the fold-over effect described above. But in this variation, the motion of the wedge  660  also increases the possible amount of flange  653  fold-over because the volume inside the cylinder  652  expands as the compaction of the wedge  660  occurs. The increasing volume thus reduces further the density of the powdered metal material under the flange  653  during the initial stages of the pressing process. The wedge  660  and cylinder  652  may be configured in various ways to increase or decrease the pressure of the fit, such as by varying the angle of the wedge  660 , the depth of the bore  25 , and the thickness, length and material properties of the flange  653 . Controlling the rollover of the flange  653 , such as within a few thousandths of an inch, may properly balance the mechanical undercut to permit for increased tensile strength of the powdered metal part. Furthermore, the exterior surface of the wedge  660  or cylinder  652  may be provided with ribs  670  for enhanced grip following the compaction process. The ribs  670  may also accommodate tolerances in the machining process by permitting material to compact in the direction of the air voids of the ribs if the bore is too tight, allowing full travel of the wedge. 
       FIG. 13A  illustrates another variation of a fastening device  800 . The fastening device  800  has an insert section comprised of a press fit shoulder  802  and an upper shoulder  804  separated by a micro void area  806 , and an upper tapered body member  808  with angled barbs  810  axially extending from the insert section. The pressing process in this variation causes material from the mechanical part  20  to roll into the micro void area, thus trapping the press fit shoulder  802 . A tight bond is ensured between the powdered metal part and the mechanical part  20  by virtue of the secure fastening device  800 .  FIG. 13B  illustrates a similar fastening device  815  with a slightly taller tapered body member. 
       FIG. 14A  illustrates a dovetailed fastening device  820 . The fastening device  820  is designed to fit into a machined slot  821  in the mechanical part  20 . Once inserted into the slot  821 , the shoulders  822  retain the fastening device  820  in place. The pressing process may further secure the fastening device  820  in the slot  821 . 
       FIG. 14B  shows another fastening device  830 . The geometric features of the device  830  and the machined cavity create pockets  834  that work to retain the powdered metal part in place once the pressing process is complete. 
       FIG. 14C  shows another fastening device  840  installed with the assistance of a support boss  50 . The fastening device  840  has a dovetail section  842  that slidably enters the guide hole  844  via the support boss  50  until firmly seating against the shoulder  848 . The pressing process forms the powdered metal part around the fastening device  840 . The geometric features of the fastening device  840  are designed with aspects of the machined mechanical part  40 , such as the lip  846 , to further bind the parts together. 
       FIG. 15A  shows a threaded fastening device  850  with a threaded base  851  that is screwed into a bore  852  in the mechanical part  20 . The end  854  of the fastening device is bulbous in nature so that the pressing process packs the powdered metal around the head in all directions. In so doing, the powdered metal part may be prevented from detachment from the mechanical part  20  by the combination of the embedded end  854  and the threaded base  851 . 
       FIG. 15B  illustrates a fastening device  860  that includes a threaded base  861 , a central body portion  862 , and a tapered distal end  863 . A stamped nut  864  is slidable over the taper end  863  so as to fit onto the central body portion  862 . The nut  864  is free to move during the pressing process so that the density of the material will be uniform above and below. The nut  864  may work in combination with the threaded base  861  to join the powdered metal part to the mechanical part  20 . 
       FIG. 16A  illustrates a powdered metal assembly  900  manufactured according to the methods described herein. The powdered metal part  10  bonds to the mechanical part  20  through the pressing process of the powdered metal in a forming apparatus. The force of the pressing action during compaction of the powdered metal drives the flanges  903  inward toward the powdered metal part to mechanically hold the parts together, as illustrated in the enlarged picture of the prototype in  FIG. 16B . The combination of the mechanical hold means and a glue bond, for example, may be used to further enhance the strength of the bond. 
     The places where the description above refers to particular implementations joining powdered metal parts to machined mechanical parts, it should be readily apparent that a number of modifications may be made without departing from the spirit thereof and that these aspects and implementations may be applied to other powdered metal parts joining machined mechanical parts. The presently disclosed aspects and implementations are therefore to be considered in all respects as illustrative and not restrictive.

Technology Category: 4