US2714450A - Method of metal forming and improved apparatus therefor - Google Patents

Description

United States Patent 6 i METHUD (1 F METAL FORMENG AND IMPROVED APPARATUS THEREFOR Robert tlhestnut, Tenatiy, N. .l., assignor to Aluminum Company of America, Pittsburgh, Pa., a corporation of Pennsylvania Original application Eseptemher 30, 1954), Serial No. 187,774. Divided and this application September 25, 1951, Serial No. 248,263

6 Claims. (Cl. 207-2) This invention relates to methods and means by which metal products may be quickly and efficiently formed, at least partly by extrusion, from metal slugs or other solid metal masses. The general object of the invention is to provide methods and means for the production in quantity and at low cost of small, accurately shaped metal pieces or small, accurately shaped articles having a pressed body and one or a plurality of projections extruded therefrom. However, the general principles of the invention are useful in connection with the production of massive articles, particularly those having a pressed body and one or more integral portions projecting therefrom.

l have developed novel methods of metal forming, an apparatus therefor, which may be used to simultaneously form a plurality of metal shapes by extruding the metal to be formed at an angle to the direction in which the extruding or forming pressure is applied. That is to say, the metal is forced through a plurality of die orifices in directions at a substantial angle, usually 20 degrees or more, to the direction of the applied pressure which is exerted on a metal mass to effect the extrusion action. In the preferred embodiment of the invention the direction of movement of the metal through the die orifice, i. e., along the longitudinal axis of the orifice, is substantially at right angles to the direction of the applied extrusion pressure. The invention includes the extrusion of the metal shapes, by such a lateral method, substantially immediately into metal receiving areas or chambers which are free of peripheral metal confining surfaces, or into spaces of infinite proportions, the result being that the metal, once shaped by the die orifice, and extruded at an angle to the direction of applied pressure, is thereafter not subjected to any metal confining surface which materially alters its cross section. If desired, however, a metal shape issuing from a die orifice may be deflected from its normal path of travel by one or more deflecting surfaces, thereby utilizing the extrusion pressure to further shape the metal without subjecting the extruding metal to dies which peripherally confine its surfaces.

The invention, its various principles, objects and advantages will more fully appear from the following description in which reference is made to the attached drawing which shows, for purposes of example and not by way of limitation, an embodiment of the invention by which articles of the described characteristics may be produced. In these drawings the eleven figures form a related group.

Fig. l is an elevational view, partially in section, of the essential parts of an apparatus embodying principles of this invention and designed for the production of a wing nut having a pressed body and extruded wing portions;

Fig. 2 is a cross sectional view taken through the apparatus of Fig. 1 as indicated by the section line 2-2 shown on the later figure;

Figs. 3 and 4 are elevational views, partly in section, of portions of the apparatus of Figs. 1 and 2 during an 2,714,4-5fi Patented Aug. 2, 1955 ice extrusion operation, the section of these views being indicated by the section line 3-3 shown on Fig. 2;

Fig. 5 is another elevational view, partially in section, of the same apparatus, the view being as indicated by the section line 55 shown on Fig. 4, and

Figs. 6 through 11 are perspective views illustrating various stages of the development of the wing nut, shown in Figs. 10 and ll, from the metal slug shown in Fig. 6 during the operation illustrated in Figs. 1 through 5.

The embodiment of my invention shown in Figs. 1 to 11, inclusive, is extremely useful for the rapid development and production of oddly shaped pieces, of which a wing nut is a particular example. Referring to Figs. 1 and 2, the elements of this apparatus include a metal confining chamber 50 defined by the complementary die blocks 51 and 52 assembled in the die ring 53 and separated by the shaped plates 54 and 55. This assembly is placed on a base 57, centered thereon by bolts 58, and the whole placed, as shown in a suitable holder 56. The bottom of chamber 59 is defined by the upper surface of the knockout element 59 which extends through base 57 and holder 56 and is movable upward by action of any suitable force applying means. If a knockout device is not necessary or desirable, the bottom of chamber 50 may be defined by a fixed element. A pressure element, the ram 60, is movably positioned to be operable into and out of chamber 59 as desired. This ram is sized to closely fit the elongate chamber 5t and the mouth of the chamber may be flared as at 61 to facilitate entry of the ram. The plates 5'4, 55 are sized to define, with the die blocks 51 and 52 a round chamber 5t and through a portion of their lengths the said plates completely fill the space between opposing surfaces of said complementary die blocks. However, through a portion of the length the plates 54, 55 are cut back, as indicated, so as to form, with the die blocks 51, 52 the metal receiving chambers 62 (best shown in 2) being on either side of the metal confining chamber 50 and opening into said chamber. While this arrangement is of considerable convenience, since plates 54 and 55 may be readily replaced by plates of differing shape without changing die blocks 51 and 52, it is, of course, possible and often practical to eliminate plates such as 54 and .75, and the metal receiving chambers may be formed by merely cutting them into die blocks such as 51 and 52. in which case these blocks are sized to form the chamber 5%. To form die apertures 63 between chamber 5t) and the chambers 62, the opposing edges of die blocks 51 and 52 are slightly enlarged and sloped toward each other, as shown with some exaggeration at 64 in Fig. 2, for a distance along their length measured by the distance between the upper surface of knockout pin 5? and the point where the chamber 50 begins to flare outwardly. The result is two slot-like die apertures 63 in the walls of chamber 5 1i and opening substantially immediately into each metal receiving chamber 62. It will now be noted that as the ram 60 descends into chamber Sit, it will progressively shorten the length of these slotlike die apertures 63. In the apparatus here shown the plates 54 and 55 are shaped to present opposite each aperture 63 a curved deflecting surface 65, the function and purpose of which will be later explained.

With reference to Figs. 1 to 11, inclusive, the operation of the apparatus will now he explained. The apparatus is designed to make from a solid metal slug, such as mass 66, a wing nut, two views of the finished form of which are shown in Figs. 10 and 11. To this end the metal mass is placed in chamber 50 and the ram 60 descends into the chamber to exert a steady extruding pressure on said mass. Under the influence of this pressure two cars or lugs 67 begin to develop from the metal mass. At this stage the metal assumes the form indicated in Fig. 7 and the cooperating parts of the apparatus are as shown in Fig. 3. As the ram 69 continues to descend the length of the slot like die apertures 63 is decreased and the metal issuing therefrom meets the deflecting surfaces 65 which are positioned in the'path of fiow of the metal from said aper tures. Under the action of the extruding pressure applied by ram 6i), the metal shape extruded from the apertures is deflected upwardly while its dimensions in the direction of the applied pressure are progressively shortened, the result being the gradual evolution of two extruded wings 67 on either side of the now pressed metal mass 66. As the extruding process continues, the surface 68 of each wing 67 is gradually tilted inwardly and advanced upwardly, as best shown in Figs. 7 to 10, inclusive. it will be noted that during the process no surrace serving to define metal receiving chambers 62 acts to peripherally confine the metal and alter the cross section thereof, the cross sec- 7 tional size and shape of the extruding wings being established by the cross sectional size and shape of die apertures 63 and the length of the extruding wings being established by the original volume of metal mass 66 and the distance to which ram es moves downwardly into chamber 50. The surfaces 65 merely act to divert and guide the flow of metal. When the ram till has progressed sulficiently into chamber St to extrude the desired amount of metal, it is withdrawn and the completed product removed by moving knockout pin 59 upwardly to eject the same. It will be noted that the longitudinal axes of the die apertures, and the directions of extrusion, are at an angle to the direction of applied extruding pressure.

It will at once be apparent to those skilled in the art of forming metal that the principles embodied in the apparatus and method just described may be readily embodied in apparatus of different form and shape and applied to the manufacture of formed metal articles of various shapes, whether the final article be formed of a pressed body with extruded parts protruding therefrom or whether the final article is merely an extruded shape such as, for

instance, would be formed by severing wings '67 from the mass 66 or by continuing the ram dil downwardly until all or substantially all of the metal mass had passed through die apertures 63.

Using the method and apparatus just described, I have produced thousands of wing nuts made of aluminum alloy with little or no variation in size from that esired. These wing nuts are characterized by a finished, attractive, precision appearance, such as is usually associated with a machined product, by a controlled strength and dimension in the center mass so which is far superior to that of wing nuts made by other methods. Such are but illustrative of the advantages to be obtained by the methods of metal forming herein described, and the improved means for performing such methods, examples of which are herein illustrated.

This application a division or my application Serial No. 187,774, filed September 3%, 1950, which is a continuation-in-part of my application Serial No. 712,832, filed November 29, i946, now abandoned.

I claim:

1. In that method of forming a metal product in which directional pressure is applied to a confined, solid metal mass to extrude metal therefrom through at least one orifice defining the cross sectional area and shape of the extruded metal, the improvement consisting in applying said pressure to said mass in a direction substantially at right angles to the direction of flow of said metal through said orifice and progressively shortening the dimensions of said mass in the direction of the applied pressure as the metal of said mass tlows through said orifice, thereby also shortening the dimensions of said orifice in the direction of the applied pressure.

2. that method of formin: a metal product in which directional pressure is a plied to a confined, solid metal mass to extrude metal therefrom through at least one orifice defining the cross sectional area and shape of the eI-"ruded metal, the improvement consisting in applying said pressure to said mass in a direction substantially at right angles to the direction of flow of said metal through said orifice, progressively shortening the dimensions of said mass in the direction of the applied pressure as the metal of said mass fiows through said orifice, thereby also short g the dimensions of said orifice in the direction the applied pressure, and deflecting the flow of said metal after it has issued from said orifice.

3. In that method of forming a metal product in which directional pressure is applied to a confined, solid metal mass to extrude metal therefrom through at least one orifice defining the cross sectional area and shape of the extruded metal, the improvement consisting in having said or fice deliver metal forced therethrough substanmediately into an area free of peripheral metal g surfaces which would alter the cross section of the denvercd metal, applying said pressure to said mass in a direction substantially at right angles to the direction of flow of said metal through said orifice, progressively shortening the dimensions of said mass in the direction of the applied pressure as the metal of said mass flows through said orifice, thereby also shortening the dimensions of said orifice in the direction of the applied pressure, and deflecting the flow of said metal in said area after it has issued from said orifice.

4. in a metal forming apparatus for the production of a formed metal product from a solid metal mass, means defining a metal confining chamber adapted to hold a metal mass, :1 die aperture disposed in and opening through a wall of said chamber, a pressure element sized to closely fit said chamber and operable to apply to a metal mass confined in said chamber directional pressure sufiicient to force metal from said mass through said aperture, said pressure element being adapted to progressively shorten the length of said aperture during its operation, and means defining a metal receiving chamber positioned to receive metal issuing from said aperture and shaped to be free ct peripheral metal confining surfaces which would alter the cross section of the delivered metal, said die aperture being so positioned between said confining chamber and said receiving chamber that metal formed in said aperture will move in a direction angular to the direction of pressure applied to said metal mass, one wall of said metal receiving chamber being positioned to oppose the flow of metal issuing from said aperture and to receive and divert metal flowing into said chamber in a direction angularly of said direction of flow from said aperture.

5. in a metal extruding apparatus, means arranged to form and define an elongate metal confining chamber having at least one elongate slot-like opening in its side through which metal confined in said chamber may be laterally extruded and a pressure element sized to closely fit said chamber and operable in said chamber to move toward the end thereof to apply extruding pressure to metal confined therein and to progressively shorten one dimension of said slot-like o, ening during an extrusion operation.

6. In a metal extruding apparatus, means arranged to form and define an elongate metal confining chamber having at least one elongate slot-like opening in its side through which metal confined in said chamber may be laterally extruded, a pressure element sized to closely fit said chamber and operable in said chamber to move toward the end thereof to apply extruding pressure to metal confined therein and to progressively shorten one dimension of said slot-like opening during an extrusion operation, and a metal receiving chamber positioned to receive metal issuing from said opening and shaped to be free of peripheral metal confining surfaces which would alter the cross section of the delivered metal, said opening being so positioned between said confining chamber and said receiving chamber that metal formed in said opening will move in a direction angular to the direction of pressure applied to said metal mass, and a surface disposed in the path of movement of metal from said opening and adapted to divert the flow of said metal in said metal receiving chamber.

References Cited in the file of this patent UNITED STATES PATENTS Mitchell Aug. 28, 1928 Kipperman et al June 6, 1939 Dunsheath Dec. 19, 1939 Talbot-Crosbie et a1. Mar. 19, 1940 Farr et a1 May 28, 1946 Jongedyk Dec. 12, 1950

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