US3593366A

US3593366A - Multiple punch tool set for powder compacting press

Info

Publication number: US3593366A
Application number: US782918A
Authority: US
Inventors: Joseph E Smith
Original assignee: Wolverine Pentronix Inc
Current assignee: Wolverine Pentronix Inc
Priority date: 1968-12-11
Filing date: 1968-12-11
Publication date: 1971-07-20
Anticipated expiration: 1988-07-20
Also published as: FR2025916A1; DE1961586A1; JPS506261B1; CH498676A; NL6918567A; BE743018A

Abstract

A tool and die set for a powder-compacting press comprising a tool capsule and a die plate having punch apertures and discharge apertures, punches for said punch apertures which may contain core rods held immovable in relation to said punches and which are lockable in position so as to be flush with the surface of said die plate and in which said punches are telescopically arranged dual punches for movement relative to each other to form shaped articles.

Description

United States Patent [72] Inventor Joseph E. Smith Birmingham, Mich.

[2|] Appl. No.' 782,918

[22] Filed Dec. 11, 1968 {45] Patented July 20, 1971 l 73] Assignce Wolvcrine-Pentronix, lnc.

Lincoln Park, Mich.

[54] MULTIPLE PUNCH TOOL SET FOR POWDER COMPACTING PRESS 22 Claims, 14 Drawing Figs.

US. Cl 18/l6.7 1329c 3/00 [50] Field ofSearch l8/l6.7

[56] References Cited UNITED STATES PATENTS 2,499,980 3/1950 Stokes,.lr. et al 18/16.? 2,883,703 4/1959 Frank t l8/l6.7 3,172,156 3/1965 Belden l8/l6.7 3,353,215 [1/1967 Haller l8/16.7

Primary Examiner-William S. Lawson AttorneyHauke, Gifford and Patalidis ABSTRACT: A tool and die set for a powder-compacting press comprising a tool capsule and a die plate having punch apertures and discharge apertures, punches for said punch apertures which may contain core rods held immovable in relation to said punches and which are lockable in position so as to be flush with the surface of said die plate and in which said punches are telescopically arranged dual punches for movement relative to each other to form shaped articles.

PATENTEU JULZO m1 SHEET 1 0F 5 Q 5 l F ATTORNEYS ATENTEU JUL20 my:

SHEET 2 OF S FIGB MT 7/ 5 6 4 m .5 3

M6 FIG? INVENTOR JOSEPH E. SMITH ATTORNEYS PATENTEU M20197! 3, 593 366 SHEET u 0F 5 FIGB INVENTOR JOSEPH E. SMITH ATTORNEYS MULTIPLE PUNCH TOOL SET FOR POWDEP COMPACTING PRESS REFERENCE TO RELA'ITEI JAPPLICATIONS The present invention is in substance related to U.S. applications Ser. No. 450,427 filed Apr. 23, 1965 (now abandoned); Ser. Nos. 529,733 and 529,734 filed Feb. 24, i966,

BACKGROUND OF. THE INVENTION The present invention relates to powder-compacting presses and more particularly to an improved tool capsule or tool and die set assembly for such presses having means providing an accurate adjustment of the die cavity dimensions by relative adjustment of the punches associated with the tool set to insure a more precise dimensional control over the finished compacted article and which mayhave means to adjust and secure acore rod associated with said punches in said tool-set assembly. I

The present invention is a modification of a tool capsule or tool and die setof the character provided as part of apowder compacting press, as for instance disclosed in U.S. Pat. Nos. 3,328,842 or 3,414,940. The powder-compacting, press and tool and die set described in U.S. Pat. Nos. 3,4l4,940:and

3,4l5,l42 consists of a machinefor the purpose of manufacturing memory cores, beads, pellets, balls, tablets or other shaped articles made of powdered ferrite, glass or other comparable powdered substances capableof forming a product upon.the'application of a pressure in a confined die cavity.

The primary purpose of the machine is the manufacture of computer memory cores which are normally toroidal, pills or tablets such as pharmaceuticals balls for. ballpointpens,

porous bearings and bushings, and the like. Computer memory cores and porous bearings or bushings normally have a toroidal or cylindrical shape, while pharmaceuticals may take the form of flat-sided or slightly crowned tablets, whereas balls for ballpoint pens are formed with a spherical shape.

Small, compacted articles often require a high degree of dimensional the finished For instance, ferrite memory cores 1 have dimensions ranging from approximately 0.005 to 0.050 inch in thickness, and from approximately 0.005 to 0.080 inch in diameter, andthe tolerance of these dimensions normally may be held within 0.000l inch. in addition to dimensional control, the density of compacted articles, specifically small bushings or bearings, memory cores or the like, must beheld accurate, thereby making it necessary that the amount of powder placed in each die cavity-of the press must be substantially the same and must be repetitively maintained within extremely close limits. The finished density of all thefinishcd articles must be the same; that is, itmust beuniform and, ac-

cordingly, the compressing of thepowdered material must be exact andrepeatedly constant. If the dimensional and density specifications. are, not held within. close tolerances, the playback level, for instance, fromthe cores in .a computer memory bank will not be ,substantiallyconstant from coreto ticles are compacted and formedin a single or multicavity die plate forming part of the tool set. The finished articles are automatically ejected from the die, picked up by a vacuum suction. head or mechanical means, and swept out through discharge ports into suitable containers. A workstationpositioner assembly, which is part of the press, is angularly movable over the die plate and carries a powder dispenser, an anvil, and a pickup head. The powder dispenser, which is supplied with powdered material from a powder material supply source connected thereto by means of a flexible tubing or the like, is

first positioned over the die cavity or cavities'to fill the cavities with powder and the powder dispenser is vibrated or oscillated to assist in filling the die cavities, while punches in the tool capsule are displaced downwardly so as to draw into the die' cavities a predetermined amount of powder. The powder dispenser is then removed by a swinging movement of the work station positioner assembly,wiping the die plate surface clean. Thereafter, the anvil is, in turn, positioned on the upper pickup head. The pickup head is then moved from over the die cavities and disposed overone or a series of discharge aperturcs arranged in a disposition similar to the arrangement of the die cavities in the die plate where the finished articles are dropped through the discharge aperture or apertures into suitable containers.

ln'the aforementioned U.S. Patents, the tool capsule or tool i and die set'for forming'an article having a toroidal, circular or cylindrical shape comprises a die plate having one or a plurality of equally spaced apertures and a punch associated with each of the apertures adapted tobe displaced in the apertures to form a confined die cavity forthe powder between the head ofthe punch and the surface of the anvil and, if desired, a core rod may be provided for centrally apertured articles associated with each of the punches which are axially adjustable within an axial longitudinal bore in the punch. The prior patents were adapted to produce only flat, cylindrical, spherical or toroidal articles with'or without apertures by the'provision of a single punch which may have an axial bore for theextension'of a core rod therethrough, if desired. As mentioned before, the core rod or rods would be held stationary and thus only the extent of movement of the single punch or punches had to be preciselycontrolled to obtain the desired density and thickness of the finished article.

However, there are manyrelatively small articles of other than tablet, spherical or toroidal form which are desirable to bemade from powdered material. Such articles may be in the shape of cylindrical cups or flanged buttons, which may have apertures parallel to their central axis, and they may be used as miniature bearings or the like. Prior to the present invention, these'articles have been made by extrusion, stamping, in-

jection molding or the like process, which are relatively slow and expensive, and not readily applicable to powdered material. By means of the novelfeatures disclosed herein, it is possible to make these small shaped articles in a conventional powder-compacting press of the type disclosed in the aforementioned patents. These novel features comprise dual,

priorto placing the tool'set in the machine. This relative ad- 'justmentis maintained during the operation of the machine,

while the punches aredisplaced axially in the cavities in a regular cycle to form compacted cylindricalor circularshaped articles. Thus, the instantaneous position and relative movement of two movable members in the die cavity need to be controlled to assure accurate dimensional consistency.

One of the problems associated with high production automatic powderlcompacting presses of this character is the maintenance of a high degree of surface finish of the various tool and die members exposed to the powder and which are responsible for the dimensional tolerance of the finished articles. To insure a high degree of acceptable dimensional tolerances, the die plate and the punches are normally formed of a hardened tool steel or tungsten carbide and the surface of the die plate and the anvil are normally provided with a super finish. However, some powdered substances, for instance, powdered ferrite, used in the formation of computer memory cores or the like, have highly abrasive properties. Thus, the upper surface of the die plate tends to become pitted as the positioner assembly, which traverses the die plate, sweeps the excess powdered ferrite from the surface of the die plate prior to moving the anvil into engagement over the filled cavities. This sweeping action tends to wear the die plate so that acceptable dimensional tolerances are lost. In addition, the upper ends of the punches become worn due to their repeated compaction of the powdered ferrite. Normally, a conventional tool capsule has to be disassembled and the working surface of the die plate refinished, and the core rods and punches refinished or replaced depending upon the amount of wear which has developed, and then the various components have to be reassembled for further utilization.

In the tool and die sets disclosed herein as preferred embodiments of the present invention the time and effort involved in renovating the working surfaces of the die plate, punches and core rods are greatly reduced by providing a structure in which the die plate, core rods, punches, punch holder and related parts are removed as one complete assembly from the press, and all the parts can be refinished simultaneously by turning the assembly face down on a conventional lapping disc. The construction of the several components is such that all of the working surfaces are adjustable relative to each other to abut the lapping disc to be simultaneously finished or lapped.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a novel unitary tool and die set for a powder-compacting press adapted to produce irregular-shaped articles from a powdered material such as cups, flanged buttons or the like, necessitating the provision of multiple punches for each die cavity which are axially movable relative to each other and one moving within the other in such way that upon compaction of the powder in the die cavity in one embodiment of the present invention flanged buttons will be produced and in another embodiment of the present invention hollow cups will be produced.

Core rods may be provided extending through the central punch in case the shaped articles are to be provided with central apertures.

Further objects and advantages of the present invention will become apparent to one skilled in the art upon reference to the following detailed description and the accompanying drawings in which like reference numerals represent like parts throughout the several views.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical cross section through one embodiment of the present novel tool and die set showing the relative position of the punches in the fill position;

FIG. 2 is a similar cross section of the same embodiment as in FIG. 1 showing the relative position of the punches in the press position;

FIG. 3 shows the relative position of the punches in the eject position;

FIG. 3a is a perspective view of the finished article made by the novel tool and die set shown in FIGS. l-3;

FIG. 4 is a transverse cross section through the present novel tool and die set of FIG. I as seen along line 4-4 thereof;

FIG. 5 is a vertical cross section through a further embodiment of a novel tool and die set according to the present invention, for making the article shown in FIG. 3a, showing the relative position of the punches in the fill position;

FIG. 6 is a vertical cross section similar to FIG. 5 showing the relative position ofthe punches in the press position;

FIG. 7 is another vertical cross section similar to FIGS. 5 and 6 showing the relative position of the punches in the eject position;

FIG. 8 is a composite transverse cross section through the tool and die set of FIGS. 5-7 as seen along line 8-8 in FIG. 6;

FIG. 9 is a vertical cross section of still another embodiment of a novel tool and die set according to the present invention for making cup-shaped objects showing the relative position of the punches in the fill position;

FIG. 10 is a vertical cross section similar to FIG. 9 showing the relative position of the punches in the press position;

FIG. 1] is another vertical cross section similar to FIGS. 9 and 10 showing the relative position of the punches in the eject position;

FIG. 12 is a composite transverse cross section of the tool and die set of FIGS. 9-ll as seen along line l2-l2 in FIG. 10;

FIG. 13 is a perspective view of the finished article made by the tool and die set of FIGS. 9I2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIGS. 1-4 which illustrate a single cavity tool and die set 20 according to the present invention for use in a powder-compacting press, the tool and die set 20 comprises a die plate 22 to one side of which is attached a tool capsule 24 by means of screws or bolts or similar means 23.

The die plate 22 is adapted to be supported on or within the work surface of the press (not shown) and is provided with an aperture 26 disposed substantially in the center of the die plate 22 and adapted to receive a die bushing 28. The internal surfaces of the die bushing 28 define a die cavity 30 for the reception of powdered material 32 (FIG. 1

The tool capsule 24 comprises a cylindrical housing 34 suspended underneath the die plate 22 to which it is attached by screws 23 extending through a flange 36. In the assembled position, the longitudinal axis of the capsule housing is axially aligned with the center of the die bushing 28. Axially centered within the housing 34 for reciprocating movement therein is a telescoping punch assembly 38 comprised of an inner punch 40 adapted for sliding movement within a cylindrical outer punch 42 which, in turn, is adapted in the assembled position to be axially aligned with and slidingly engaged with the inner surface of the die bushing 28. The lower end of the inner punch 40 is secured to the head portion of a ramrod 44 which imparts a reciprocating movement to the inner punch 40. A substantial portion of the lower end of the inner punch 40 is externally threaded as at 46 to rotatably receive an internally threaded axially adjustable abutment member 48. A pinlike insert 50 of preferably plastic material is provided through a cross-drilled bore in the lower end of the threaded portion of the inner punch for engagement with the internal threads 47 to lock the abutment member 48 in the adjusted position. The adjustable abutment member 48 has a reduced outer end portion 52 for extension through the bottom opening 35 of the capsule housing 34 and is preferably provided with spaced radial blind bores 54 into which a suitable tool may be inserted to rotate the abutment member 48 for axial adjustment along the threaded end 46 of the inner punch 40. The portion of the abutment member 48 within the capsule housing 34 is provided with external threads 56 to adjustably receive an internally threaded cylindrical sleeve 58 for upward extension therefrom and sliding movement within the capsule housing 34. The sleeve 58 is normally held in a locked position relative to the abutment member 48 by means of plastic, or the like, thread inserts 60 unless a rotational force is applied to the sleeve to overcome the frictional resistance of the insens 60 opposing rotation of the sleeve. Thus, normally, the sleeve 58 will be rotated in unison with the abutment member 48-upon rotation of the latter unless it is held stationary by a tool or the like. As can be seen, the sleeve 58 and the abutment member 48 may be rotated for adjustment independently of each other to axially adjust these two members relative to each other and relative topunch 40..

The upper end of the cylindrical sleeve 58'-is formed with an inwardly extending circumferential flange portion 62. which inner diameter defines a central aperture 64 for the extension of the outer punch 42 therethrough. The lower. end of the outer punch '42 is provided with an outwardly circumferentially extending flange 43" disposed within the sleeve 58' to be retained within the upper end of the sleeve 58 by means of the sleeve flange 62 which prevents movement of the outer punch 42 outwardly of the sleeve. As can be seen in the Figures, both the outer punch 42 and the adjustable abutment 48 are contained within the sleeve 58and the upper surface 49' of the abutment 48 and the flange 43 of the outer punch 42 are normally axially spaced' from each other, as seen. in FIG. I, a predetermined distance D," which determines the axial movement of the punches 40 and 42' relative to eachother by which the fill and press position of the punches is determined in order to obtain the desired thickness and density of the finished article.

In the fill position, as shownin FIG. 1, which shows the relative position of the punches of the tool and die set in. the powder fill position, the ram- 44 has retracted the punch assembly 38 a predetermined amount so as to allow thedic-cavity 30 to be filled with powdered material 32. As can be seen, the inner punch 40 is retracted further than: the outer punch 42, thus providing in effect a secondary die'cavity 68 defined by the internal diameter of the outer punch 42' and the upper end of the inner punch 40. The actual depth of both the primary die cavity 30 and secondary die cavity 68- is determined by the relative position of the sleeve 58 inregard to the abutment 48 since the flanged connection of the sleeve 58 with the flanges 43 of the outer punch 42 regulatesthe extent that the outer punch extends into the die bushing 28. Thus, by screwing the sleeve 58 downwards upon the abutment 48, the outer punch 42 is caused to be extracted further from the die cavity 30 shortening the distance 0D,", and by screwing the abut ment 48 up on the inner punch the outer punch is caused to extend further into the die cavity 30-during the pressing operation. The fill retraction and press extent of the inner punch 40 is governed by the movement 'of the ram 44', which can likewise be adjusted by the initial machine setup.

In the press position, as shown in FIG. 2, the punch assembly 38 has moved to the maximum press position initiated by the upward movement of the ram 44. In this position, the

inner punch 40 has advanced relative to the outer punch a distance corresponding to the'distance "D" so that the abutment 48 now abuts against the flange 43 of the outer punch 42 and the flange 62 of the sleeve 58-is extended upwardly away from the flange 43 of the outer punch 42.

After the

die cavities

30 and 68 have been filled with the proper amount of powdered material by any conventional filling means (not shown), the ram 44 is actuated by the press mechanism for reciprocation as an anvil means or the like is placed over the die cavities. The inner punch 40 is advanced first by the ram 44 independently of the outer punch 42 which remains stationary at this stage. This is made possible by the As seen in FIG. 2, further movement of the ram 44 causes the surface 49 of the abutment 48 to engage against the flange 43 of the outer punch 42 whereupon both

punches

40 and 42 are moved simultaneously a short distance for the final compression of the article 66. As can be seen by comparing FIGS. 1 and 2 the inner punch 40 moves a further distance than the outer punch 42 due to its independent movement at the beginning of the pressstroke for initially compressing the powder.

The. initial position: of the

punches

40 and 42 relative to each. other, as illustrated in-FlG. l, is adjustable by relative rotation of the abutment 48 and sleeve 58 to permit a suffcientv amount of powder to fill the die cavities and 68, and to limit the length of the strokes of the punches relative to each other in order to produce the article 66 of FIG. 30 having the required dimensions and density.

Referring to FIG. 3, after final compression, the article 66 is ejected. from the-die cavity 30 by a final stroke of the punch assembly 38' moving both

punches

40 and 42 simultaneously to. permit the removal of the article. Thereafter, the punch assembly returns to its original fill position as in FIG. 1 causing first the inner punch 40 to be moved independently of the outer punch 42 until the flange 62 of the sleeve 58 comes in contact with the flange 43 of the outer punch 42, whereafter both

punches

40 and 42 are again moved together to resume the positionshown in FIG. 1.

It will be understood that any known press mechanism such as, for example, disclosed in U.S. Pat. No. 3,328,842or similar ones, may be used in conjunction with the present tool anddie set herein disclosed.

With reference to FIGS. 58, there is shown a multiple cavity tool and die set 74 adapted to produce a shaped article similar tothe article 66 shown in FIG. 3a.

' tool capsule 80 extending underneath thereof. The tool capinitial free movement afforded between the abutment 48 and flange 43 of the outer punch 42 which is defined by the distance 0D." For the particular article 66, FIG. 34 made by this tool and die assembly, it is desired to compact first the center portion which provides the shank 70 of the article 66 in order to compress the powdered material into the flange portions 72 of the article to compact the powder around the edges and into the comers of the die cavities to obtain a high quality internal grain structure with no voids present. This is of specific importance around the comer where the shank 70 joins the flange 72 to thus avoid the occurrence of internal stresses caused by the otherwise relatively weak cross section.

sule comprises a cylindrical housing 82 provided with a centralbore 84 in alignment with the die cavities 81 which contains a multiple punch assembly 86. The lower end of the housing 82 is closed by a plate 88 attached thereto by screws 90. The plate 88 has a central aperture 92 to permit the extension of a. punch actuating rod 94 therethrough to be disposed within the housing 82. The lower end of the punch actuating rod 94 is attached to the head of a reciprocating ram indicated at 44 for reciprocation of the punch assembly 86.

The punch actuating rod 94, which is part of the punch assembly 86, is provided with a first toolholder in the form of an enlarged head portion 98 provided with a relatively deep annular groove 100. The upper end of the head portion 98 is provided with equally angularly spaced, radially outwardly extending slots 102 as seen in FIG. 8, which join the annular groove 100 and which number corresponds to the number of die cavities provided in the die plate 76. Each of the slots 102 is adapted to receive an inner punch 104 which has an annular enlarged flange portion 106 at its end of a thickness such as to fit within the annular groove 100 to be retained therein. It will be seen that the depths of the groove 100 and the slots 102 are of such dimensions as to allow the inner punches 104 to radially float therein in order to permit them to be axially aligned with the center of the die cavities 81'.

The punch actuating rod 94 is provided below the head portion 98 with screw threads 108 adapted to receive an adjusting nut 110 for axial movement along the punch actuating rod 94. The nut 110 moves with the punch actuating rod 94 upon reciprocation of the latter partly through the central aperture 92 in the bottom plate 88.

The punch actuating rod 94, including the head portion 98, is surrounded within the housing 82 by a tubular sleeve or cup member 112 which is axially independently movable within the housing 82 between an upper and lower limit position as will be described.

The cup member 112 is in the shape of an inverted cup having a closed top portion 114 and an open bottom portion, which is closed by a detachable plate 116 attached to the cup by means of screws 118. The bottom plate 116 has a central aperture 120 to permit the extension of the punch actuating rod therethrough. The top portion 114 of the cup 112 comprises a second toolholder having an increased wall thickness to allow the provision of an annular groove 122 therein. The flange 124 created by the groove 122 is provided with a plurality of radially outwardly extending slots 126 which join the groove 122. As shown in FIG. 8, the slots 126 are equally angularly spaced around the flange 124 and correspond in number to the number of die cavities in the die plate 76. In assembly, the slots 126 of the toolholder 114 will be aligned with the slots 102 in the head portion of the punch actuating rod 94 and are adapted to receive hollow cylindrical outer punches 128 which have a radial flange 130 at the lower end therein on the toolholder 114. The depths of the groove 122 and the slots 126 are sufficient to permit the outer punches 128 to be axially aligned on center with the die cavities 81. In assembly, and as shown in the drawings, the hollow cylindrical outer punches 128 are adapted to telescopingly fit over the inner punches 104 for axial sliding movement relative thereto and for extension into the die cavities 81.

As shown in this embodiment, the inner punches 104 are axially bored through to permit the insertion of a core rod 132 in each of the punches for free sliding movement therein. The core rods 132 extend downwardly freely slidable through apertures 134 in the head portion 98 of the punch actuating rod 94 and, further, through apertures 136 in the bottom plate 116 of the cup 112 which are aligned with apertures 134 to permit free sliding movement of the core rods. The lower ends of the core rods 132 are individually secured within the bottom plate 88 of the housing 82 by means of individual setscrews 138 which are radially inserted through the side of the plate 88. The core rods 132 can thus be longitudinally adjusted by loosening the setscrews 138 and moving the core rods upwards through the inner punches 104 until their top end is flush with the top surface of the die plate 76. The setscrews 138 are then tightened to securely lock the core rods to the stationary housing 80 so that upon reciprocation of the punch assembly 86 the core rods will stay in place.

As mentioned before, the head portion 98 of the punch actuating rod 94 and the surrounding cup 112 are adapted for reciprocation relative to each other in one stage of the operation and for unitary reciprocation movement in another stage of the operation. This is determined by the spacing D (FIG. between the upper surface 97 of the head portion 98 and the underside 113 of the toolholder 114 of the cup 112, which can be adjusted by rotation of a plurality of adjustable setscrews 140 provided in the bottom plate 116 against which the head 98 abuts in the fill position of the punch assembly as seen in FIG. 5 thus regulating the extent of the punches within the die cavities during the powder fill operation. By adjusting the nut 110 along the punch actuating rod 94, the maximum press extent of the outer punches 128 within the die cavities 81 can be regulated. In the lowermost or fill position of the punch assembly as shown in FIG. 5, the head portion 98 of the punch actuating rod has been moved downward within the cup 112 and towards the bottom plate 116 until the head portion 98 cup 112 which tends to bias the cup upwardly to maintain engagement of the setscrews 140 against the underside of the head portion 98 and thereby likewise maintaining the position of the outer punches 128 within the die cavities 81 during the fill cycle.

As shown in the drawings, the outer punches 128 extend further into the die cavities 81 than the inner punches 104, thus providing a secondary die cavity 144 (FIG. 5). This arrangement is similar to that in FIGS. 1-4 to produce a similar button-type article as shown in FIG. 3a with the exception that a central bore is provided through the article by the provision ofthe core rods 132.

In the powder fill position as shown in FIG. 5, the

die cavities

81 and 144 are filled with powdered material 32 by any such means as disclosed in the aforementioned U.S. Patents.

In the press position shown in FIG. 6, after complete filling of the die cavities, an anvil means 25 is placed over the die cavities and the press cycle is initiated by upward movement of the ram 44 when actuated by the press mechanism (not shown). Initially, the inner punches 104 will be moved independently of the outer punches 128 by their direct connection to the head 98 of the punch actuating rod 94. The head portion 98 is caused to move upward within the cup 112, thereby compressing the spring 142 and advancing the inner punches 104 up on the stationary core rods 132 for an initial compression of the powder within the die cavities 144. The outer punches 128 will not be moved during this stage until the adjusting nut on the punch actuating rod 94 comes to abut against the bottom plate 116 of the cup 112 as seen in FIG. 6. Further upward movement of the punch actuating rod 94 thereafter causes the outer and inner punches to be moved simultaneously since the cup 112 that supports the outer punches 128 is taken along by the nut 110. The combined stroke of both outer and inner punches causes final compression of the powder within the

die cavities

81 and 144 to produce an article 66a having a shank portion 70a and a flange portion 72a, which is also provided with an axial bore 71 caused by the use of the core rods 132. (FIG. 7).

In the eject position shown in FIG. 7, after removal of the anvil means 25 from atop the die cavities 81 a final stroke of the ramrod 44 causes the finished article 6611 to be ejected from the die cavities, whereupon they can be removed from the punches.

Upon return movement of the punch assembly 86 to the initial fill position shown in FIG. 5, the retreat of the punch actuating rod 94 first causes the inner punches 104 again to be moved independently of the outer punches 128 until the head portion 98 comes to rest upon the setscrews in the bottom plate 116 of the cup 112. After this, the punch assembly will be moved as a unit to assume to position in FIG. 5. The spring 142, during the receding movement of the punch actuating rod, expands to exert a constant force on the cup 112 to prevent the cup 112 from dropping down in the housing 82 by gravity force as the nut 110 moves away from the bottom plate 116 upon return movement of the punch actuating rod 94.

With reference to FIGS. 912, this embodiment illustrates a multiple cavity tool and die set 148 constructed and adapted to produce a cup-shaped article 150 as shown in FIG. 13.

The tool and die set 148 is composed of a die plate 152 having a plurality of equally spaced apertures 154 (two of which are shown) which are preferably arranged in a circle and which are adapted to receive die bushings 156 press-fitted therein and which internal bores define die cavities 158. Attached to the underside of the die plate 152 by screws 160 is a tool capsule 162, which comprises an open cylindrical housing 164 having a straight axial bore 166. The open lower end of the housing 164 is closed by a detachable plate 168 attached to the housing by means of screws 170. The plate 168 has a central aperture 172 to permit the extension therethroug'h of a punch actuating rod 174 which extends into the housing 164 for actuation of a multiple punch assembly 176 for reciprocation within the housing 164, by means of a press ram 44 to which the lower end of the punch actuating rod 174 is connected.

The punch actuating rod 17 4 fwhich is part of the punch assembly 176, is provided with a first toolholder in the form of a diametrically enlarged head or flange portion 178 provided with an annular groove 180. The upper side of the enlarged head portion 178 is provided with a plurality of radially outwardly extending slots 182 which join the groove 180. The slots 182 are equally spaced around the head portion 178 as seen in FIG. 12 and correspond in number to the number of die cavities provided in the die plate 152. The slots 182 are adapted to receive each a hollow cylindrical outer punch 184 each provided at its end with a radial flange 186 which fits into the annular groove 180 by which the punches 184 are held in the slots 182. In assembly, the punches 184 will be aligned with the die cavities 158 for extension thereinto.

The intermediate portion of the punch actuating rod l74is provided with screw threads 188 for threading engagement with a longitudinally adjustable ring or nut 190 adapted to normally move with the punch actuating rod through the aperture 172 in the plate 168 upon reciprocation of the latter. The nut 190, at one stage of the press operation, is adapted to abut against a second toolholder in the form of a ring 192 which is loosely mounted by way of a central aperture 194 around the punch actuating rod 174 between the head portion 178 and the nut 190 for axial movement relative to the punch actuating rod. The ring 192 is of sufficient thickness to accommodate the provision of an annular groove 196. An upper flange 198, formed by the groove 196, is provided with a plurality of radially outwardly extending slots 200 which join the groove 198. The slots 200 are equally spaced around the flange 198 as seen in FIG. 12 and correspond in number to the number of die cavities in. the die plate 152. The slots 200 are adapted to receive each an inner punch 202 having each a flange portion 204 at its lower end which fits into the groove 198 to thus retain the punches 202 on the ring 192; The inner punches 202 will be aligned with their respective outer punches 184 to slidably extend therethrough and into the die cavities 158. The inner punches 202 are bored through to slidingly receive each a core rod 206 which extend downwardly through aligned apertures 208 in the bottom portion of the ring 192 and which are secured within the bottom plate 168 by means of individual setscrews 210 radially inserted from the side of the plate 168. Thus, the core rods 206 can be longitudinally adjusted to be flush with the surfaceof the die plate 152 and are thereafter locked to the stationary housing by means of the setscrews 210 to stay in place during reciprocation of the punch assembly 176.

As shown in the drawings, the inner punches 202 extend further into the die cavities 158 than the outer punches 184 providing a secondary die cavity 212 (FIG. 9) around the tip of the inner punches 202 which, upon compression of the powder in the die cavities, produces the cylindrical wall 151 of the cup-shaped article 150 in FIG. '13.

The fill and press extent of the

punches

184 and 202 within the die cavities and their movement relative to each other and together during the pressing operation can be precisely adjusted to obtain the desired thickness and density in the wall and bottom portion 155 of the cupshaped article 150. This is accomplished by moving the nutl90 up or down on the punch actuating rod 174, which determines the maximum extent of the inner punches 202 during the press operation.

The relative axial spacing of the outer punch 184 in regard to the inner punch 202 is determined by the adjustable spacing D" (FIG. 10) between the head portion 178 of the punch actuating rod 174 and the freely movable ring 192. To adjust the spacing D, adjusting screws 214 have been provided-in the ring 192 which are positioned along the outer edge of the ring to extend therethrough between the slots 200 as seen in FIG. 12. In the retracted or fill position of the punch assembly as seen in FIG. 9, the head portion 178 is caused to abut upon the adjusting screws 214 of the ring 192 so that upon adjustment of the adjusting screws 214 the initial fill position ofthe outer punches can be adjusted accordingly. The adjusting screws 214 can be adjusted from outside the tool housing 164 by means of aligned apertures 216 provided in the bottom plate 168.

in the fill position as shownin' FIG. 9, the

die cavities

158 and 212 are filled with powdered material 32 by any known means. After the filling, an anvil means or the like 25 is placed over the die cavities (FIG. 10) and the ram 44 is actuated by the press mechanism (not shown) to move the punch assembly 176. In the initial stage of movement, the outer punches 184 which are directly attached to the head 178 of the punch actuating rod 174 are first moved independently of the inner punches 202 to initially compress the walls of the cup-shaped article and to compact the powder into the bottom portion of the article against the surface of the anvil means 25. Upon further movement of the punch actuating rod 174, the nut engages the ring 192 to which the inner punches 202 are secured to thus move the inner punches simultaneously along with the outer punches for the final compressing stroke into the position indicated in FIG. 10. Thereafter, the anvil or the like is removed from the die cavities and an ejection stroke is applied to the punch assembly 176 to eject the finished articles 150 from the die cavities for removal from the press. This. position is shown in FIG. 11.

In this embodiment in comparison to the embodiments in FIGS. [-8, the outer punches are moved first instead of the inner punches to compact the powder into the bottom portion of the cup-shaped article. If the arrangement would be reversed by moving the inner punches first, a relatively weak bottom portion and high density wall portion would be obtained which is undesirable.

lf core rods are being used as illustrated, the finished cup article 150 will be provided with an aperture 153 in the bottom portion 155. However, in this, as in the foregoing embodi-' ments, core rods may be omitted or, on the other hand, instead of a single center core rod, multiple core rods for each die cavity may be employed. The use and arrangement of the core rods form no part of the present invention.

For reconditioning of any of the novel tool and die sets herein disclosed, the tool and die set is removed from he press as a unit and placed upside down upon an appropriate lapping tool or the like whereupon the inner and outer punches can be axially adjusted by their respective adjusting means to abut the lapping tool, in which position they can be locked in place for movement across the lapping tool.

The present novel tool and die sets as herein disclosed provide improved arrangements for multiple punch tool and die sets allowing for precise adjustment of the relative positions and movements of the associated punches to produce shaped articles from powdered materials.

Tl-le present invention may be embodied in certain other forms without departing from the essential characteristics therefrom. Therefore, the present embodiments are to be considered in all respects as illustrative only and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description.

What we claim is:

1. A punch and die assembly for a powder-compacting press for making shaped articles, said punch and die assembly comprising a die plate having at least one die cavity opened at opposite ends and adapted to be filled with a powdered material, a punch assembly associated with said die plate having at least a pair of punches consisting of an outer punch and an inner punch slidingly arranged one within the other for extension into one of said ends of said die cavity, overlapping anvil means dependent from said press and adapted to engage a surface of said die plate for closing the other end of said die cavity, a punch actuating rod axially aligned with said punches and adapted to reciprocate and support said outer and said inner punch, means associated with said punch actuating rod to adjustably vary the extent of said outer and said inner punches within said die cavity relative to each other, said punch actuating rod being adapted to move one of said punches independently of the other punch to initially compact said powdered material against said anvil means, and abutment means carried by said punch actuating rod engageable with said other punch so as to move said outer and said inner punches together as a unit for final compaction of said powdered material in said die cavity against said anvil means.

2. The punch and die assembly as defined in claim 1, wherein said punch actuating rod has means to support one punch of said pair of punches for reciprocation therewith and a sleeve member associated with said punch actuating rod having means to support the other of said pair of punches.

3. The assembly as defined in claim 2, in which said sleeve member surrounds said punch actuating rod in axially free sliding position relative thereto when said punch actuating rod is in one position and for reciprocating movement therewith when said punch actuating rod is in another position.

4. The assembly as defined in claim 2, in which said means to adjustably vary the extent of said outer and said inner punches relative to each other comprises an adjustable abutment member on said punch actuating rod adapted for abutment with said sleeve member to thus vary the axial position of said sleeve member relative to said punch actuating rod, and adjustable abutment members on said sleeve member adapted to vary the relative axial position of said punch supported on said punch actuating rod in relation to said punch supported on said sleeve member.

5. The punch and die assembly as defined in claim 2, further comprising a ram member adapted to move said punch actuating rod independently of said sleeve member to initially compact said powdered material in said die cavity by means of said punch supported on said punch actuating rod and said abutment means comprises an abutment member on said punch actuating rod for abutment with said sleeve member to move said sleeve member conjointly with said punch actuating rod for final compaction of said powdered material in said die cavity by conjoint movement of said inner and said outer punch.

6. A multiple punch tool and die set assembly for compacting powder to produce shaped cylindrical articles comprising a reciprocable punch actuating rod having an enlarged head portion for the support of a first set of a plurality of punches thereon, a sleeve member positioned in freely surrounding relationship to said punch actuating rod for axial movement relative thereto having means to support a second set a plurality of punches in coaxial telescopic arrangement with said first set of punches, adjustable means on said punch actuating rod to adjustably limit the axial movement of said sleeve member in relation to said punch actuating rod, first means to cause initial movement of said punch actuating rod independently of said sleeve member and second means to cause final simultaneous movement of said punch actuating rod with said sleeve member.

7. In the assembly as defined in claim 6, in which said adjustable means on said punch actuating rod comprises, an abutment member axially movable along said punch actuating rod adapted for abutment with said sleeve member to determine the relative axial position of said sleeve member in relation to said punch actuating rod.

8. In the assembly as defined in claim 7, in which said sleeve member has the shape of an inverted cup having a closed top placed over said head portion of said punch actuating rod and said means to support said second set ofa plurality of punches comprises an annular groove in said closed top and a plurality of radial slots equal in number to the number of said plurality of punches to receive and retain said punches within said annular groove.

9. In the assembly as defined in claim 7, in which a resilient means is provided between said sleeve member and said punch actuating rod to maintain said sleeve member in position relative to said punch actuating rod when said sleeve member is not in contact with said abutment member.

10. In the assembly as defined in claim 6, adjustable means associated with said sleeve member for varying the relative axial position of said second set of punches in relation to said first set of punches.

ll. In the assembly as defined in claim 6, in which said first set of punches are provided with axial bores to receive core rods therein.

12. In the assembly as defined in claim 6, in which said second set of punches are provided with bores to receive core rods therein.

13. In the assembly as defined in claim 6, in which said sleeve member comprises a ring having an annular groove and a plurality of radial slots for the reception and retainment of said second set of punches.

l4. ln the assembly as defined in claim 13, adjustable means associated with said ring for varying the relative axial position of said second set of punches in relation to said first set of punches.

15. A tool and die set for a powder-compacting press comprising a die plate having at least one aperture defining a die cavity, a tool capsule attached to said die plate, said tool capsule containing a punch assembly for reciprocation therein, said punch assembly comprising a punch actuating rod provided with at least one telescopically arranged pair of punches adapted for extension into said die cavity, first means to support the first punch of said telescopically arranged punches on said punch actuating rod, second means to support the second punch of said telescopically arranged punches on said punch actuating rod independently of said first means, means to axially adjust the rclative axial position between said first punch and said second punch of said telescopically arranged pair of punches, first means associated with said punch actuating rod upon application of force to cause said first punch of said telescopically arranged pair of punches to move into said die cavity independently of said second punch of said telescopically arranged pair of punches in a first stage of operation, second means associated with said punch actuating rod to cause said first and said second punch of said telescopically arranged pair of punches to move conjointly into said die cavity in a second stage of operation.

16. In the tool and die set defined in claim 15, said means to axially adjust the relative axial position between said first punch and said second punch comprising a plurality of adjusting members associated with said punch actuating rod and with said second means to support said second punch independently of said first means.

17. In the tool and die set defined in claim 15, said first punch provided with an axial bore to receive a core rod therein.

18. In the tool and die set defined in claim 15, said second punch provided with an axial bore to receive a core rod therein.

19. In the tool and die set defined in claim 15, said means to support the first punch of said telescopically arranged punches on said punch actuating rod comprising an enlarged head portion on said punch actuating rod, an annular groove provided in said enlarged head portion, radial slot means joining said annular groove, said first punch adapted to be placed in said slot means and being provided with a flange adapted to be retained in said annular groove.

20. In the tool and die set defined in claim 19, said means to support the second punch of said telescopically arranged punches on said punch actuating rod independently of said first means comprising a sleeve member freely surrounding said punch actuating rod for axial movement relative thereto in one position of said punch actuating rod and conjoint movement therewith in another position of said punch actuating rod, said sleeve member provided with annular groove means, radial slot means joining said groove means and aligned with said radial slot means in said enlarged head portion, said second punch adapted to be placed in said radial slot means for telescopic engagement with said first punch and being provided with a flange adapted to be retained in said annular groove means.

21. A punch tool and die set assembly for compacting powder to produce shaped articles comprising a reciprocable punch actuating rod, a die plate having a die cavity, a punch assembly associated with said die plate and having at least one set of dual punches comprising an outer punch and an inner punch slidably arranged one within the other for coaxial telescopic extension into said die cavity, said punch actuating rod adapted to initially move said inner punch independent of said outer punch initially to compact said powder material in said die cavity, an adjustable abutment member carried by said punch actuating rod and adapted for abutment with said outer member carried by said abutment member, said sleeve member being axially adjustable relative to said adjustable abutment member, said sleeve member having means engaging said outer punch to withdraw said outer punch from said die cavity after said inner punch has been withdrawn a predetermined distance.

i FORM PO-IOSO (10-69] PEN- iUtS-A UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO- 3, 593, 366 Dated July 20, 1971 Inventor(s) Joseph E. Smith It is certified that error appears in the above-identi ied patent and that said Letters Patent are hereby corrected as shown below:

IN THE SPECIFICATION Column 3, line 2, correct the spelling of "powder compacting" Column 5, line 42, change O"D, to "D",

line 66, change 0"D. to "DD" Column 6, line 40, change reference numeral "70" Column 7, line 23, after "end" insert thereof adapted to fit into the groove 122 to be retained 7-- Column 8, line 38, before "which" insert and Column 10, line 47, change "TI-1e" to The IN THE CLAIMS Column ll, line 38, after "set" insert of Sirzned and sealed this 15th day of February 1972.

(SEAL) Attast:

ROBERT GOTTSCHALK EDWARD M.FLETCHER,JR.

Commissioner of Patents Attesting Officer USCOMM-DC 60376-5 69 U1. GOVIINMENT rmm'ms orncz m0 0-4004

Claims

8. In the assembly as defined in claim 7, in which said sleeve member has the shape of an inverted cup having a closed top placed over said head portion of said punch actuating rod and said means to support said second set of a plurality of punches comprises an annular groove in said closed top and a plurality of radial slots equal in number to the number of said plurality of punches to receive and retain said punches within said annular groove.

11. In the assembly as defined in claim 6, in which said first set of punches are provided with axial bores to receive core rods therein.

14. In the assembly as defined in claim 13, adjustable means associated with said ring for varying the relative axial position of said second set of punches in relation to said first set of punches.

15. A tool and die set for a powder-compacting press comprising a die plate having at least one aperture defining a die cavity, a tool capsule attached to said die plate, said tool capsule containing a punch assembly for reciprocation therein, said punch assembly comprising a punch actuating rod provided with at least one telescopically arranged pair of punches adapted for extension into said die cavity, first means to support the first punch of said telescopically arranged punches on said punch actuating rod, second means to support the second punch of said telescopically arranged punches on said punch actuating rod independently of said first means, means to axially adjust the relative axial position between said first punch and said second punch of said telescopically arranged pair of punches, first means associated with said punch actuating rod upon application of force to cause said first punch of said telescopically arranged pair of punches to move into said die cavity independently of said second punch of said telescopically arranged pair of punches in a first stage of operation, second means associated with said punch actuating rod to cause said first and said second punch of said telescopically arranged pair of punches to move conjointly into said die cavity in a second stage of operation.

21. A punch tool and die set assembly for compacting powder to produce shaped articles comprising a reciprocable punch actuating rod, a die plate having a die cavity, a punch assembly associated with said die plate and having at least one set of dual punches comprising an outer punch and an inner punch slidably arranged one within the other for coaxial telescopic extension into said die cavity, said punch actuating rod adapted to initially move said inner punch independent of said outer punch initially to compact said powder material in said die cavity, an adjustable abutment member carried by said punch actuating rod and adapted for abutment With said outer punch after said inner punch has initially moved to thereby move both said inner and outer punches into said die cavity as a unit for final compaction of said powder material in said die cavity, said adjustable abutment member surrounding said punch actuating rod and adapted for independent axial movement along said actuating rod.

22. The assembly as defined in claim 21 including a sleeve member carried by said abutment member, said sleeve member being axially adjustable relative to said adjustable abutment member, said sleeve member having means engaging said outer punch to withdraw said outer punch from said die cavity after said inner punch has been withdrawn a predetermined distance.