US3103038A

US3103038A - Powder pressing apparatus

Info

Publication number: US3103038A
Application number: US59324A
Authority: US
Inventors: Michael W Zolton
Original assignee: REFRACTO MET Inc
Current assignee: REFRACTO MET Inc
Priority date: 1960-09-29
Filing date: 1960-09-29
Publication date: 1963-09-10
Anticipated expiration: 1980-09-10

Description

Sept. 10, 1963 M. w. ZOLTON POWDER PRESSING APPARATUS Filed Sept. 29, 1960 2 Sheets-Sheet 1 Michael W. Zo/fon IN VENTOR.

BY Attorneys and Sept. 10, 1963 M. w. ZOLTON 3,103,038

POWDER PRESSING APPARATUS Filed Sept. 29, 1960 2 Sheets-Sheet 2 Michael W z /Ion United States Patent Vania Filed Sept. 29, 1960, Ser. No. 59,324 Claims. (Cl. 18-16) This invention relates to novel apparatus for forming solid shaped bodies from powdered metal, ceramic, plastic, and the like by compaction of the powdered material.

The formation of shaped objects from powdered materials has heretofore been accomplished by apparatus involving either rolling powdered material into solid sheets or press compaction of the material into a desired shape.

It will therefore be apparent that the physical aspects of the previous apparatus are restricted in the shapes or configurations into which the powdered materials may be transformed as is characteristic of the processes involving rolling. Press compaction processes are restricted as to the extent of the object to be formed because of the required pressure and load requirements imposed on the press and its inability to form a larger object having substantial uniform density.

It is therefore a primary object of this invention to provide a novel apparatus for compacting powdered materials into a wider range of shapes and at a significantly lower cost than was heretofore possible.

Another object of this invention is to provide a novel apparatus whereby a greater variation in size and shape is possible with equipment employing significantly lower forces in compacting powdered material.

A further object of this invention is to provide a novel apparatus for compacting powdered materials into desired shapes and sizes of objects wherein the dimensions, densities and other properties of the finished object may be predicted in advance thus eliminating subsequent investigation of dimensions, densities, etc.

The apparatus of this invention therefore involves as the physical forming portion thereof, the use of a ram actuated wedging mechanism for applying a continuously moving pressure over incremental areas of .a surface of the powdered material which is confined within a die forming chamber. Accordingly, the force necessary to generate the requisite pressure for compacting the powdered material into a rigid formation may be of a lower magnitude inasmuch as the force is applied over a relatively small area. Also, in view of the continuous movement of the compaction pressure over the entire surface with a constant and uniform compaction pressure, the finished object may be made with uniform density. It is therefore apparent that by use of sequentially applied continuously moving wedging mechanism moving at any desired speed and reacting against forming surfaces with any desired shape and variation, the compacting pressure requirements of the particular powdered material used may be accommodated in :order to form any desired shape with uniform or if so desired, non-uniform density. It will therefore be appreciated that the apparatus of this invention involves a radical departure from the convention-al method of compaction wherein a total and necessarily large force must be applied by the press over a total area in a single movement in order to compact the powdered material and form therefrom the desired object by the instantaneous localization of a significantly smaller compacting force to a small area at the requisite compaction pressure. The previous press compaction apparatus therefore while theoretically able to produce objects of any size become impractical in dealing with objects having lengths even as short as six inches since "ice the cost of the equipment necessary to generate the requisite pressures and temperatures outweigh by far any advantage which may be obtained from forming the objects by the press compaction process. Furthermore, the press compaction apparatus which is closest in principle to the apparatus of this invention is inherently incapable of obtaining the dimensional uniformity and predictability possible with the apparatus of this invention. Also, the equipment with which the instant apparatus is performed will not only be relatively simple and economical in construction but also readily adaptable for applying other powder treatments to the powdered material.

These together with other objects and advantages which will become subsequently apparent: reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer tolike parts throughout, and in which:

FIGURE 1 is a top plan view with parts broken away with one form of apparatus for performing the novel process of this invention.

FIGURE 2 is a sectional view taken through a plane indicated by section line 2--2 in FIGURE 1.

FIGURE 3 is a sectional view taken through a plane indicated by section line 3-3 of FIGURE 1.

FIGURE 4 is a perspective view of a finished object formed by the compaction process by use of the apparatus illustrated in FIGURES 1 through 3.

FIGURE 5 is a top plan view of another form of apparatus for performing the novel process of this invention.

FIGURE 6 is a sectional view taken through a plane indicated by section line 66 in FIGURE 5.

FIGURE 7 is a sectional view taken through a plane indicated by section line 7-7 in FIGURE 6.

FIGURE 8 is a sectional view taken through a plane indicated by section line 88 in FIGURE 6.

FIGURE 9 is a perspective view of a finished object formed by the novel process choosing the apparatus of FIGURES 5 through 8.

Referring now to the drawings in detail, FIGURES 1 through 3, illustrate one form of apparatus whereby the novel compaction process may be performed. It will be observed that the compaction apparatus generally indicated by reference numeral 10 is mounted on a base or machine bed 12 which machine may be part of apparatus for performing various treatments upon the powdered material other than the physical compaction thereof by the apparatus 16. Accordingly, apparatus 10 may be modified or disassembled for other process steps, the structure illustrated merely being exemplary for the purpose of demonstrating the principles and concepts of the novel aspects of the process. For example, a trough 14 or mold container is provided having

sides

16 and 18 land a bottom 20 as more clearly seen in FIGURE 3, said trough defining therein a die chamber within which the powdered material is confined with sufficient strength as to prevent dimensional elongation of the powdered material under compaction pressure. Although the die chamber 22 is illustrated as rectangular in shape, it should be appreciated that the actual shape of the chamber will depend upon the desired shape of the object to be formed.

Adjustably mounted above the die chamber 22 by means of :a plurality of adjusting screw members 24 is a cover member 26. It will be appreciated however that any type of adjustment mechanism may be provided other than that illustrated for adjustably spacing the cover member 26 above the trough 20. Also carried by the top cover member 26 is a forming die member 28 which may be assembled thereto in any suitable manner as for example by dovetailing as seen in FIGURE 3. Accordingly, the forming die member 28 may be removed and replaced by other shaped forming members or removed for purposes of applying other treating equipment to the powdered material confined within the trough 20.

It will therefore be observed that the powdered material is confined within the forming chamber 22 of the trough 14 by means of retaining

members

30 and 32 disposed at the ends of the trough 14. The retaining

members

30 and 32 are yieldably displaceable in a downward direction against the bias of spring 34 and include

beveled edges

36 and 38 respectively.

It will therefore be apparent that the retaining

members

30 and 32 while retaining the powdered material within the trough 14, may be displaced downwardly when engaged by a ram member generally indicated by reference numeral 40 which strikes the

beveled edges

36 and 38. The ram member 40 is therefore disposed between the upper surface of the powdered material and the lower surface 42 on the forming guide member 28. The r-am member includes a leader portion within which a plurality of guide rollers 46 are rotatably mounted. The guide rollers 46, it will be observed, are of such dimensions as to position the ram 40 within the space between the lower surface 42 of the guide member 28 and the top surface of a metallic sheathing 48 disposed above the loose powdered material 50 which is accordingly confined between the sheathing 48 and the bottom 20 of the trough 14. It will therefore be apparent that the guide roller 46 may align the ram member 40 and optionally apply an initial displacing pressure on the sheathing 48 to begin compacting the powdered material 50 which is in loose form.

Following the leader portion 44 of the ram member 40 is a wedging roller 52 which is of such a dimension as to displace the sheathing 48 relative to the bottom surface 42 of the guide member 28 so as to compact therebeneath the compacted powdered material 54. The roller 52 therefore presents a Wedging surface which slides relative to the contacting surfaces on the guide member 28 and sheathing and rolls about its axis in response to any.

difference between the frictional forces respectively developed on the confronting contact surfaces that resist movement of the wedging roller therebetween. Rollers are used because of the relatively small contact surface presented through which the compaction force is applied to develop the localized compaction pressure of requisite value to compact the powdered material. It is therefore apparent that the ram member 40 by being moved in the direction of arrows in FIGURES l and 2 will cause the roller members to sequentially apply the displacing pressure to the sheathing 48 to thereby compact therebelow the powdered material. The degree of compaction and the angle of compaction will therefore be determined both by the shape of the wedging mechanism which in the illustrated case are rollers Iandthe shape of the surface 42 on the guide member 28. Also, the shape of the object formed by the compaction of the mounted material will be determined by the shape of the chamber 22 of the trough 14. In the example illustrated in FIGURE 4, a rectangular shape flat bar member 56 is formed by use of the apparatus illustrated in FIGURES 1 through 3.

In connection with the above described process and apparatus it will be apparent that any suitable mechanism may be used to provide for continuous movement of the ram member 40 as the wedging rollers thereof pack the powdered material. The selected rate of the speed of the member 40 as well as the compaction angle and shape will therefore depend upon the properties of the powdered materials subjected to the compaction pressure and the desired shape and size of the object to he so formed. Accordingly adjustment of the cover member 26 will be necessary. Also it should be appreciated that the guide member 28 may be removed from the cover member 26 so that the cover member may alternatively support other equipment for example tamping devices to level and otherwise treat the powdered material prior to compaction thereof by the apparatus. Also, the apparatus may have the benefit of heating equipment, vacuum applying equipment and other such process steps to which the powdered material may be subject. that additional variations in shape may be achieved by the gauging of the rollers and the use of wed-ging mechanism of different shape such as balls, drifts and wedges of different configurations. In addition, different sequence combinations in the application of a wedge containing rams may be resorted to if so desired.

FIGURES 5 through 8 illustrate a second form or variation of the apparatus :by means of which the novel process may be performed. The latter form therefore includes a forming chamber 58 of cylindrical configuration formed by the cylindrical member 60. The loose powdered material 62 is therefore confined between the annular wall of the chamber 58 and a cylindrically formed sheathing 64. Similar retaining members are therefore disposed at the ends of the cylindrical members 60 which is mounted on the base 66. The retaining members 68 are therefore segmental in shape and are spring biased inwardly by means of spring 70.

-A ram member 72 is provided including a leader portion 74 which rotatably mounts rollers 76 and 78 disposed perpendicular to each other so as to guide the leader member 74 on the cylindrical wall of the sheathing 64. The leader portion 74 is therefore followed by the wedging member 80 of spherical shape which member 80 applies the compacting pressure to compact the powdered material 82 between the annular wall 58 of the cylindrical member 60 as the wedging roller 80 progresses therealong. In the case of this form of the invention, no separate forming guide member is needed for the wedging element in order to develop the requisite compaction pressures, since the annular configuration of the molding chamber 58 also replaces the function of the guide member 28 as described in connection with FIGURES 1 through 3. It will therefore be apparent that the apparatus of FIG URES 5 through 8 will compact and form a cylindrical object 84 as seen in FIGURE 9.

From the foregoing description, it will be appreciated that a wide variation in the shape of objects formed by the novel process may be obtained and different types of powdered material may be accommodated in a manner and to an extent not possible by previous processes. It will therefore be appreciated that dimensional variations may be obtained by use of wedges of different shapes including balls, rollers, cones, etc. Also the differently contoured wedges may be used in sequence or simultaneously and the speed of movement thereof varied by use of any suitable mechanism including for example explosively discharging actuators. Also, the controlled application of heat, vacuum and atmosphere as well as the changing of the dies or chambers constitute other variations pursuant to the concepts of this invention. It is also contemplated that objects of different materials may be formed in one piece by the compaction process of this invention. Although not illustrated, all of the above noted variations in the forming process of this invention are inherently possible with the process and apparatus of the instant invention which variations were not possible with any single particular type of process previously resorted to for compacting pow-dered material. The essential ingredient rendering all of the above advantages possible in the novel process of this invention is the fact that a continuous compaction of the powdered material is performed over incremental areas of the powdered material. Accordingly, the action is not interrupted by raising or lowering a compacting member or by adding incrementally to the powdered material which render previous processes unable to accomplish the objectives of this invention.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous Also, it should be understood J modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

:What is claimed as new is as follows:

1. The apparatus as defined in claim 26, wherein said chamber and sheathing are annular in shape.

2. Apparatus for molding powdered material capable of being formed into a solid body when subjected to a predetermined compaction pressure comprising, molding chamber means for confining a predetermined volume of said powdered material in an unpressurized state while exposing a compaction surface thereof to pressure, wedge means for instantaneously directing a compacting force of sufiicient magnitude against said compaction surface over an incremental area thereof to subject said surface to a localized pressure equal to said compaction pressure, ram means operatively connected to said wedge means for displacement and generation of said compacting force by a unidirectional displacing force in a direction parallel to said compaction surface to locationally displace and uniformly apply said localized pressure throughout said compaction surface, said chamber means comprising a rigid die forming chamber and a flexible sheathing enclosing the powdered material within the chamber and in contact with the compaction surface thereof, and forming guide means with which said wedge means reacts to apply said compaction pressure to the powdered material.

3. Apparatus for compaction of powdered materials capable of forming a solid cohesive body when subjected to a compaction pressure comprising, mold means for confining said powdered material to a predetermined external surface shape under said compaction pressure, compaction surface means displ-aceable under said compaction pressure to displace the powdered material Within the mold means for compaction thereof, ram means movable at a controlled rate of speed in spaced relation to the compaction surface means, and wedge means operatively connected to the ram means for moving engagement with said compaction surface means to apply a moving compaction force thereto over an instantaneous localized area of contact producing said compaction pressure, said wedge means comprising movable Wedge surface means mounted on the ram means and guide surface means in contact with the wedge surface means for controlling the compaction pressure applied to the compaction surface means in response to movement of the wedge surface means relative to the guide surface means.

4. Apparatus for molding powdered material capable of being formed into a solid body when subjected to a predetermined compaction pressure comprising, molding chamber means for confining a predetermined volume of said powdered material in an unpressurized state while exposing a compaction surface thereof to pressure, wedge means for instantaneously directing a compacting force of sufiicient magnitude against said compaction surface over an incremental area thereof to subject said surface to a localized pressure equal to said compaction pressure, ram means operatively connected to said wedge means for displacement and generation of said compacting force by a unidirectional displacing force in a direction parallel to said compaction surface to locationally displace and uniformly apply said localized pressure throughout said compaction surface, said chamber means comprising a rigid die forming chamber and a flexible sheathing enclosing the powered material within the chamber and in contact with the compaction surface thereof.

5. Apparatus for molding powdered material of the type capable of being formed into a solid cohessive body, due to a predetermined compaction pressure applied thereto, comprising, a molding chamber having retractible end walls for confining a predetermined volume of said powdered material in an unpressurized state, a flexible sheathing disposed on an exposed surface of said powdered material within the molding chamber for continuous compression of the powdered material by forces applied to the flexible sheathing, guide means mounted in spaced relation to the molding chamber, ram means operative in response to a predetermined displacing force applied thereto for movement between said flexible sheathing and said guide means retracting said retractable end walls in response to such movement and wedge means mounted on the ram means and having substantially line contact with said guide means for engaging incremental areas of the flexible sheating in response to movement of the ram means with a compacting force operative to produce said compaction pressure on localized portions of the powdered material.

References Cited in the file of this patent UNITED STATES PATENTS 374,065 Heaton Nov. 29, 1887 949,505 Snelling Feb. 15, 1910 1,282,161 Zatzke Oct. 22, 1918 1,308,111 Porzel July 1, 1919 1,335,475 Bergman Mar. 30, 1920 1,469,761 Yunck Oct. 2, 1923 2,039,204 Young Apr. 28, 1936 2,424,278 Kunpel July 22, 1947 2,730,760 Bibby June 17, 1957 2,830,320 Geppert Apr. 15, 1958 2,888,740 Danis June 2, 1959 13,064,312 Bronfman Nov. 20, 1962 FOREIGN PATENTS 535,888 Belgium Mar. 15, 1955

Claims

2. APPARATUS FOR MOLDING POWDERED MATERIAL CAPABLE OF BEING FORMED INTO A SOLID BODY WHEN SUBJECTED TO A PREDETERMINED COMPACTION PRESSURE COMPRISING, MOLDING CHAMBER MEANS FOR CONFINING A PREDETERMINED VOLUME OF SAID POWDERED MATERIAL IN AN UNPRESSURIZED STATE WHILE EXPOSING A COMPACTION SURFACE THEREOF TO PRESSURE, WEDGE MEANS FOR INSTANTANEOUSLY DIRECTING A COMPACTING FORCE OF SUFFICIENT MAGNITUDE AGAINST SAID COMPACTION SURFACE OVER AN INCREMENTAL AREA THEREOF TO SUBJECT SAID SURFACE TO A LOCALIZED PRESSURE EQUAL TO SAID COMPACTION PRESSURE, RAM MEANS OPERATIVELY CONNECTED TO SAID WEDGE MEANS FOR DISPLACEMENT AND GENERATION OF SAID COMPACTING FORCE BY A UNIDIRECTIONAL DISPLACING FORCE IN A DIRECTION PARALLEL TO SAID COMPACTION SURFACE TO LOCATIONALLY DISPLACE AND UNIFORMLY APPLY SAID LOCALIZED PRESSURE THROUGHOUT SAID COMPACTION SURFACE, SAID CHAMBER MEANS COMPRISING A RIGID DIE FORMING CHAMBER AND A FLEXIBLE SHEATHING ENCLOSING THE POWDERED MATERIAL WITHIN THE CHAMBER AND IN CONTACT WITH THE COMPACTION SURFACE THEREOF, AND FORMING GUIDE MEANS WITH WHICH SAID WEDGE MEANS REACTS TO APPLY SAID COMPACTION PRESSURE TO THE POWDERED MATERIAL.