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Publication numberUS3671157 A
Publication typeGrant
Publication dateJun 20, 1972
Filing dateJan 25, 1971
Priority dateJan 25, 1971
Also published asCA965918A1, DE2202753A1
Publication numberUS 3671157 A, US 3671157A, US-A-3671157, US3671157 A, US3671157A
InventorsSmith Joseph E
Original AssigneeWolverine Pentronix
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Die and punch assembly for compacting powder material
US 3671157 A
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Description  (OCR text may contain errors)

J. E. SMITH 3,671,151

DIE AND PUNCH ASSEMBLY FOR COMPACTING POWDER MATERIAL June 20, 19 72 5 Sheets-Sheet 1 Filed Jan. 25, 1971 8 2 p w q w 0 2 a, a Iv w. fl; H ,8 v #55; J M v w a m a 6 3 4W Z Z v m w a a 7 a 0 M u 0 2 Z n a 4 0 4 J an M 6 & n M 5 e 3. 0 4 a 2 I'll W M r I \B 1!; 6 I 5 6 l 4 /0 M, W r w 6 -z 6 ILuW r z w INVENTOR JOSEPH ESMITH June 20, 1972 J. E. SMITH 3,671,157

- DIE AND PUNCH ASSEMBLY FOR COMPACTING POWDER MATERIAL Filed Jan. 25, 1971 3 Sheets-Sheet 2 Fig-6 INVENTOR JOSEPH E. SMITH g/fw'neys J. E. SMITH 3,671,157

DIE AND PUNCH ASSEMBLY FOR COMPACTING POWDER MATERIAL June 20, 1972 3 Sheets-Sheet 5 Filed Jan. 25, 1971 Fig-7 INVENTOR JOSEPH E. SMITH always 3,671,157 Patented June 20, 1972 United States Patent cc 1 3,671,157 DIE AND PUNCH ASSEMBLY FOR COMPACTING "POWDER MATERIAL 1 Joseph E. "Smith, Birmingham, Mich., 'assignor to Wolverine-Pentronix, Inc., Lincoln Park,'Mich. I Continuation-impart of applications Ser. No. 782,918, Dec. 11,1968, now Patent No. 3,593,366, and Ser. No. 49,800, June 25, 1970. This application Jan. 25, 1971, Ser. No.,109,37 5

Int. Cl. 133% 11/02 US. Cl. 42578 14 Claims ABSTRACT OF DISCLOSURE A die and punch assembly foruse onapowder compacting. press, for making articles compacted from a powder material. The assembly comprisesfa die plateappropriately mounted to the press and includes one or more die cavities, each die cavity having telescopically arranged inner and outer punches adapted for movement relative to each other to form various shaped articles. T e uter punch is actuated by a first punch support which, in ,turn, is carried by a pair of posts extending below; the die plate to permit reciprocal movement of the outer punch within-the die cavity, whilethe inner punch iscarried by a second punch support.which, in turn, is slidably. carried by the post in a position below the first punch support. An actuating stem, operatively connected to one of the punch supports, is adapted to impart a reciprocal movement thereto and includes an adjustable abutment member adapted to engage the other punch supports to displace the latter in an upward direction together with the first punch support as, a unit after the actuating stem has moved the first punehsupporta predetermined distance toward the die cavity. The secondpunch support has an adjustable, abutment member cooperating with the actuating stem ,to

and other powdered substances capable of forming a subretract both punch supports as .a unit away from the die I cavity after an article has been :ornpacte d-v in the die cavity. I a

A core rod' may be provided withor'ie enddisposed in a longitudinal bore formed-within the inner punch, while the other end of the core rod is fixedly mounted to a core rod support which in turn, is fixedly supported by the post below the second punch support. Resilient means are provided between the actuatirrg fstern and the. second punch support to maintain the-secondpunch support in position relative to the die cavity when the second punch support is not'engagedby the. adjustable abutment member. carried by the actuatingste m A (I I) Description of the prior art The present inventionis an improvement over an apparatus. of the character provided-as part of the powder compacting press disclosed: in -the aforementita'nedUS.

stantially solid article upon the application of pressure iri-a confined molding cavity. The primary purpose of such'presses is the manufacture of computer memory cores, porous bearings and bushings, transistor headers, substrates for micro-circuits and the like. Such computer memory cores, porous bearings and bushings, and the like, may'have 'a'toroidal, cylindricahsquare or rectangular shape which often requires a high degree of dimensional controLFor instance, ferrite memory cores have dimen-' sionsranging from approximately .005" to' .015" in thickness and approximately .005" to' .025 in diameter,

andthe tolerance of these dimensions normally must be held within"one tenth of one thousandth of an inch.

In addition to dimensional control, the density of compacted articles of this character, such as memory cores, must be held accurate, thereby making it necessary that the amount of powder pressed in each die cavity ofthe pres'sfrnust-be substantially the same and must be repetitively maintained within extremely close limits. The

finished density of all finished articles must be the same, that is,they must be uniform; accordingly, the compress ing of the powdered material must be exact and repetitively constant. If these dimensional and density specifications" are notheld within the specified tolerances, the play-back level from the cores in the computer memory bank will not be substantially constant from core to core."

In order to-realize acceptable dimensional tolerances, it is necessary that the compacting press be capable of accurate adjustment of the movement of several component parts' 'within at least 25-50 millionths of an inch, and that precautions be taken to insure a correct fill of each die cavity r In the? preferredembodiments' of powder compacting presses disclosed in several of the aforementioned pat ents'and' 'p'atent application, the articles are compacted and formed in multi-ca'vity dies. Finished articles are automatically ejected from'the-die cavities, picked' up by a vacuum suction head, and delivered into, vials or bottles. A flipperassembly, which is part of the press, and which includes a secondary powder hopper, an anvil, and a vacuum pick-up head disposedsubstantially side-by-side', is mounted movable transversely over the'dieplate: The secondary powder hopper, which is supplied with pow der from a'primary hopper connected thereto b y'm'eans of a flexible tubing, is -first positioned over the" die"cavities which are filled with powder as the punchesa're displaced downwardly so as to draw into thedie cavities a predetermined amount ofpowder. l'he hopper is vibrated to aid in fillingeach die cavity. The secondary "hopper is removed from over the die cavities by'a subsequent motion of 'the flipper assembly,'the edges of the hopperwiping the die plate surface clean from excess powder, and'is replaced "by the anvil which, in turn, is clamped into position on the upper surface of the die plate-and over the die'cavities. The powder in each die cavity is com pactedagainst the anvil 'asthe result of displacing the punch toward the anvil surface. The anvil is then removed from its position over the die cavity or cavities andreplace'd by the vacuum pick-up head. The pu'nch or punches are then further upwardly displaced so as to bring-their, upper ends substantially flush or preferably slightly above the surface of the die plate so that the fin ished compacted articles are ejected from the die cavities and picked up by the pick-up head. The pick-up head is then moved from over the die cavity or cavities and disposed over one or a series of discharge apertures 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 or the like simultaneously with the secondary hopper being positioned over the die cavities.

:In the aforementioned U.S. patents, a punch and die assembly is provided for forming an article having a toroidal, circular or cylindrical shape, which comprises a die plate having one or a plurality of equally spaced apertures and a punch associated with each of the apertures and adapted to be displaced in the aperture to form a confined die cavity for the powder material between the head of the punch and the surface of the anvil; and, if desired, a core rod may be provided for centrally apertured articles. The core rods associated with each of the punches are axially adjustable within an axial longitudinal bore in the punch. The core rods are normally held stationary and thus only the movement of the punch or punches has to be precisely controlled to obtain the desired density and thickness of the finished article. With the exception of co-pending patent application Ser. No. 782,918, the patents and co-pending applications referred to hereinbefore disclose punch and die assemblies adapted to produce only fiat cylindrical, spherical or toroidal shaped articles, with or without core apertures.

However, there are many relatively small articles other than tablet, spherical or toroidal shape articles which are desirable to be made from powdered material. Such articles may be in the shape of cylindrical cups or flanged buttons, they may be provided with apertures parallel to their central axis and they may be used as miniature bearings or the like. Such articles are generally made by extrusion, stamping, injection molding, or like processes which are relatively slow and expensive, or when they are made by powder material compacting methods they are made by means of complex multi-punch tools mounted in machines having a punch operating ram for each punch in the tools. By means of the novel apparatus disclosed in U.S. patent application Ser. No. 782,918 and the present application, it is possible to make small shaped articles compacted from powder material by way of a multi-punch tool mounted in a powder compacting press of the type disclosed in the aforementioned patents and provided with a single punch actuating ram.

The present invention represents a further advancement over the prior art aforementioned application in that it provides an improved and considerably simplified structure including telescopically arranged punches which are axially movable relative to each other in a precisely adjusted relationship to compress powdered material within a die cavity to form shaped articles such as cup-shaped or flanged button-shaped parts, and the like, and which are actuated by the reciprocating motion of a single actuating ram or rod.

SUMMARY OF THE INVENTION The present invention relates to a die and punch assembly for a powder compacting press for making from powder materials irregularly shaped articles such as cupshaped, flanged button-shaped parts and the like, comprising a multiple punch assembly for each die cavity, all the punches being actuated by a single control member and being axially movable relative to each other and one within the other in such a way that upon compaction of the powder in the die cavity in one example of the present invention flanged button-shaped articles are produced, and in another example of the invention cupshaped articles are produced.

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

Other objects, advantages, and applications of the present invention will become apparent to those skilled in the art of powder compacting presses whena description of several examples of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and in which:

FIG. 1 represents a fragmentary vertical sectional view of a die and punch assembly as seen along line 1--1 of FIG. 6 and shown in fill position with a hopper over the die cavity and the die cavity filled with powdered material;

FIG. 2 represents a fragmentary vertical sectional view of the die and punch assembly as seen along line 2-2 of FIG. 6 with the assembly shown in fill position;

FIG. 3 represents a fragmentary vertical sectional view of a die and punch assembly as'seen along line 3-3 of FIG. 6 with the assembly shown in fill position;

FIG. 4 represents a fragmentary vertical sectional view similar to the die and punch assembly illustrated in FIG. 1 with an anvil disposed over the die cavity and the assembly shown in press position;

FIG. 5 represents a fragmentary vertical sectional view similar to FIG. 2 with an anvil disposed over the die cavity and the assembly shown in press position;

FIG. 6 represents a fragmentary bottom view of the die and punch assembly illustrated in FIG. 1;

FIG. 7 represents a fragmentary vertical sectional view of a modified die and punch assembly as seen along line 7-7 of FIG. 8 and shown in a fill position with a hopper over the die cavity and the die cavity filled with powdered material;

FIG. 8 represents a fragmentary bottom view of the die and punch assembly illustrated in FIG. 7;

FIG. 9 represents a fragmentary vertical sectional view of the modified die and punch assembly as seen along line 7-7 of FIG. 8 with an anvil disposed over the die cavity and the assembly shown in the press position; and

FIG. 10 is a fragmentary sectional view of the modified die and punch assembly as seen along line 10-40 of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, and in particular to FIGS. 1, 2 and 3, there is shown an example of the present invention in the form of a die and punch assembly 10 having a the plate '12 adapted to be seated in the counterbore 13 of a table '15 (FIG. 1) which, in turn, forms a portion of a powder compacting press (not shown). The die plate 12 has a flat upper surface -14 and is held to the table 15 by any suitable means such as clamps, screws or the like (not shown). The die plate 12 is provided with a cylindrically shaped aperture 18 formed about an axis 20 which is disposed normally to the upper surface 14 of the die plate 12. A cylindrically shaped die bushing 22, preferably formed of a hardened material such as a carbide, is retained within the aperture 18 by a suitable adhesive material disposed between the outer periphery of the die bushing 22 and the surface of the aperture 18. A suitable adhesive material is Loctite which is described in greater detail hereinafter. The manner in which the die bushing 22 is inserted within the aperture 18 is described in the aforementioned patent application Ser. No. 49,800, and a further description thereof is not necessary as the assembly features form no part of the present invention. As can best be seen in FIG. 1, the die bushing 22 is inserted into the aperture 118 such that the upper surface 19 of the die bushing 22 is flush with the upper surface .14 of the die plate 12.

The die bushing 22 has a centrally disposed bore 24 which extends normally, downwardly from the upper surface 19 of the die bushing 22 and is provided with a chamfered portion 26 at thefl'ower end thereof. Although only one bore 24 is shown, it' is to be understood that the die bushing 22. may be provided with a plurality of mutually parallel bores disposed in a circular arrangement around the axis 20 ofthe die bushing 22 and havingla regular peripheral spacing with each of the parallel bores extending normally downwardly from the upper surface 19 of the die bushing 22 and each bore being provided with a chamfered portion 26 at the lower end thereof.

With reference to IEIG. 3, it can be seen that the die plate 12 is further provided with a pair of longitudinal bores 28 and 29 radiallyspaced from the axis 20 by a predetermined equal distance. Associated with eachbore 28 and '29 there is one of a pair of downwardly extending support posts 32 and 34 respectively. Support posts 32 and 34 are of an elongated cylindrical shape and are retained within their respective bores 28 and 29 with any suitable adhesive, or otherwise fastened into the bores 28 and 29 such as by a press-fit assembly or by means of set screws. v y I Axially centered within the die bushing 22 for. reciprocating movement, there is provided a telescopic assembly 39 comprising a cylindrical inner punch 40 adapted for sliding movement within a cylindrical outer punch 42 which, inturn, is adapted to be axially aligned with and slidably engaged within the die bushing 24. The lower end of the outer punch 42 is secured to anupper punch support 44 which is provided with a centrally disposed bore 46 supporting a cup-shaped support member 48 having an outer periphery complementary to the bore 46 of the upper punch support44. The support member 48 has a shoulder 50 abutting an annular recess 52 formed in the bore 46 to provide axial support for the support member 48, while the support member 48, in turn, supports a punch insert 54 having. a centrally disposed bore 56 in which the lower end portion ofthe outer punch 42 is received. The punch insert bore 56 and the outer punch 42 have an adhesive applied to their engaged surfaces to'secure the outer punch 42 therein. The punch insert 54 is similarly bonded to the cup-shaped support member 48, while the support member 48 is, in turn, mounted t the upper punch support 44 by the adhesive. I e With reference to FIG. 3, it canbe seen that the upper punch support 44 has a pair of longitudinalbores 58 and 60 which are radially spaced "from the axis 20' by the same distances as the die'plate bores 28'and 29 to permit a sliding engagement between the upper punch support 44 and the posts 32 and 34 respectively, and to axially align the upper end oftheouter punch 42 with the die bushing bore 24 such that the outer punch'42 extends axially upwardly fronrthe upper punch support 44 to register with the diebushing bore 24. The inner punch 40 which is slidably disposed within a longitudinal bore 62in the outerpunch 42 extends downwardly through the cup-shaped support member'48 and is supported at its lower end by a lower punch support 64. The'lower "punch support 64 isprovided with a centrally disposed bore 66 supporting acup-shaped member 68 having an outer periphery complementary to the bore 66 of the lower punch support 64 and includes a shoulder 70 mating withan annular recess 72 formed in the bore 66 toprovide axial support for the member 68. The cupshaped support member 68 supports a punch insert 76 having a centrally disposed bore 78 in which the lower end of the inner punch 40*is received-"Hie punch insert 76, the innerpunch 40,'th ecup-shape'd sup port member 68 and the lower punch support 64 are all bonded to one another in the same "manner asher'einbefore described in the description of the upper punch support 44. i 1 p The lower punch support 64 has a pair of longitudinal bores 80 and 82 (FIG. 3) which are radially spaced from the axis 20 by the same distances as the die plate bores 28 and 29 to permit a sliding engagement between the lower punch support 64 and the posts 32 and 34, respectively, so as to align the upper end of the inner punch 40 with the longitudinal bore 62 of the outer punch 42, such that the inner punch 40 extends axially up from the lower punch support 64 through the cupshaped support member 48 to register with the outer punch bore 62 and to extend in axial alignment with the outer punch 42 into the die bushing bore 24.

The outer diameters of the outer, punch 42 and the inner punch 40 accurately fit respectively the inner diameters of the die bushing bore 24 and the longitudinal bore 62 in the outer punch 42 and both project into the die bushing bore 24 such as to define a die cavity 86 therein. Although not shown, the embodiment illustrated in FIGS. 14 may be provided with a core rod of the type similar to the core rod disclosed in the embodiment illustrated in FIGS. 7-10 and which will be described in greater detail hereinafter. I

When a multi-die bushing is used, a plurality of telescopic punch assemblies 39 are provided and arranged in the same configuration as the die bores such that each punch assembly 39 is disposed in axial alignment with its respective die bore. v

I The upper punch support 44 and the lower punch support 64 function to transmit an upwardly directed force from an actuating stem 88 to the powder material 90 (FIGS. 1-3) within the die cavity 86 to form a compacted cup-shaped article 92 (FIGS. 4 and 5) as will be described in greater detail hereinafter.

With reference to FIGS. 2 and 6, it can be seen that the upper punch support 44 is coupled to the actuating stem 88 by means of a plate member 94 and a pair of threaded fasteners 96. The plate member 94 has a pair of diametrically opposed bores 98 and 100 (FIG. 3) which slidably engage the posts 32 and 34, respectively, to guide the plate member 94 during reciprocal movement thereof. The plate member 94 is connected directly to the upper punch support 44 by the threaded fasteners 96 (only one of which is illustrated in FIG. 2), each of which extends axially upwardly through a bore 102 in the plate member 94 and threadedly engages the upper punch support 44 as shown at 104. A sleeve member 106 surrounds each fastener 96 with the upper and lower end faces of each sleeve member 106 being respectively in abutment with the lower and upper surfaces of the upper punch support 44 and the plate member 94. Thus, as the fasteners 96 are threaded into the upper punch support 44, the support 44 and the plate member 94 are fixedly secured to one another and reciprocate as a unit under the motion of the actuating stem 88. The actuating stem 88 has an upper end portion 108 bonded or otherwise attached to a bore 110 which is centrally disposed within the plate member 94. Diametrically opposed bores 112 (FIG. 2) disposed in the lower punch support 64 slidably receive the outer periphery of the sleeve members 106 and, as can best be seen in FIG. 6, the fasteners 96 are angularl'y displaced from the support posts 32 and'34.

A spring128 (FIGS. 2 and 5) is disposed around each sleeve 106 with its opposite ends in abutment with the underside of the lower punch support 64 and the upper surface of the plate member '94, respectively, to bias the punch support 64 and the plate member 94 away from each other and maintain the lower punch support 64, and thus the inner punch 40, in a predetermined position relative to the plate member 94 and the die cavity bore 24 when the assembly is in the fill position illustrated in FIGS. 1-3. The plate member 94 is also provided with diametrically opposed bores 114 (FIGS. 2 and 5), each having a threaded surface in which an adjustable abutment member 116 is threadedly engaged. The upper ends 118 of the adjustable abutment members 116 are adapted to abut the lower surface of the lower punch support 64 when the actuating stem 88- moves the plate member 94 in an upwardly direction to drive the lower punch support 64 upwardly, and thus drive the inner punch 40 within the longitudinal bore 62 of the outer punch 42.

As can best be seen in FIG. 4, the lower punch support 64 also has diametrically opposed threaded bores 120 in which a second pair of mechanical abutment-members 122 are threadedly engaged and which extend down- Wardly therefrom and are slidably received in diametrically opposed bores 124 in the plate member 94. Each member 122 has an enlarged end portion 126 which abuts the lower side of the plate member 94 when the actuating stem 88 is moved downwardly so as to drive the lower punch support 64 downwardly and withdraw the inner punch 40 from the die cavity bore 24.

A suitable adhesive which may be used between the bonded elements described hereinbefore may be of a commercial quick-setting bonding compound such as an anaerobic adhesive which will securely maintain the die bushing 22 within the aperture 18 when subjected to pressure during the compacting operation. An example of'one of such bonding compounds is known and marketed under the name of Loctite manufactured by the Loctite Corporation, Newington, Connecticut. The compound, particularly useful in the bonding of cylindrical parts, is an anaerobic adhesive having unusually high shear strength exceeding that of conventional press-fitted parts by up to five times. The Loctite retaining compound is-fast curing and has excellent heat and solvent characteristics, as well as providing high shear strength between adjoining interfaces. A more detailed description of the Loctite retaining compound may be had by reference to US. Patent No. 3,621,534.

For purpose of illustration, a typical powder compacting cycle includes a powder filling step, a compacting step, and an ejection step. Briefly, the filling step is diagrammatically shown in FIGS. 1, 2 and 3 and comprises a powder supply device, which is commonly referred to as a hopper 130 and which is disposed over the die'plate 12 completely encompassing the die bushing 22 and which fills the die cavity 86 defined by the die cavity bore 24 and the upper ends of the inner and outer punches 40 and 42 with the powdered material 90. The punches are displaced downwardly from the upper surface 19 of the die bushing 22 by the action of the actuating stem 88 being moved downwardly so as to insure that the cavity 86 is filled with the powdered material 90. The hopper 130 may be vibrated to insure a complete filling of the-die cavity 86. After the filling operation, with the punches shown in the position of FIG. 1, the hopper 130 is removed -by means (not shown) and the upper surface 19 of the die bushing is wiped clean of any excess powder, which can be accomplished by the hopper 130 being moved transversely across the upper surface 19 of the die bushing 22. The upper surface 19 of the die bushing 22 is preferably polished to a super-finish so that there is no possibility of any grain of powder remaining on the surface 19 after the wiping step.

Referring to FIGS. 4 and 5, an anvil 132 supported by any suitable means (not shown) is transferred over the filled die cavity 86 and clamped into position. As can be seen in FIG. 2, when the die and punch assembly is in the fill position the upper ends 118 of the abutment members 116 carried by the plate member .94 are displaced from the lower surface of the lower punch support 64 by a predetermined amount which is dependent upon the amount of compaction desired. Thus, when the actuating stem 88 is actuated to move upwardly to compact the powder material within the die cavity 86-only the upper punch support 44, and thus only the outer punch 42 will initially move upwardly in the die bushing bore 24. After the actuating stem 88 has moved the mechanical abutment members 116 a suflicient distance to engage the underside of the lower punch support 64, the upper and lower punch supports and thus the inner and outer punches move together as a unit to compact the powdered material 90 contained within the die'cavity 86 against the anvil 132 to form the compacted finished artitile 92 having a cylindrical cup-shape (FIGS. 4 and 5).

8 After compaction of the article 92, the anvil 132 is removed from over "the die cavity 86 and the inner and outer punches 40 'and'"42" are preferably displaced upwa'rdly so that their ends are substantially flush with the upper surfaces 19 of the'die bushing 22' so that'they eject the finished article 92 which may be picked up by any suitable means, such as the vacuum pick-up described in the aforementioned patents, removed from the'die cavity 86 anddeposited in any suitable container.

After ejection of the compacted article 92, the'actuating stem 88 moves downwardly withdrawing only the outer punchd 42 downwardly in the die bushing bore 24, while the bias of thesprings 128 maintains the lower punch support 64 and thus the inner punch 40 man upward position with respect'to the die bushing bore 24 until the enlarged ends 126 of abutment members 122 carried by thelower punch support 64 are-engaged by the lower surface of the plate member 94, as shown in FIG. 1, 'at which time both the upper'and lower punch supports move-downwardly, together as a unit withdrawing the punches 40 and 42 from the die bushing bore 24 to their initial fill position wherein the cycle is repeated.

"Referring to FIGS. 7-10 wherein another example of the present invention-is illustrated in the form of a die and punch assembly 200 which is adapted to compact articles in the sha'pe'of flanged buttons. The die and punch assembly 200 has a die plate 212 adapted to be seated in the counterbore 214 of a table 215 (FIG. 7) which, in turn, forms a portion of-the aforementioned powder compacting press. The die plate 212, which is similar to'the die plate 12' hereinbefore described, has a flat upper surface 216 and is held to the .table215 by any suitable means. The die plate 212 is similarly provided with a cylindrically shaped aperture 218 formed about an vaxis 220 and accommodates a cylindrical shaped die bushing 222. The die bushing 222 has a centrally disposed bore 224 which extends normally downwardly from the upper surface 221 of the die bushing and is shown with a ch mfered portion 226 at the lowerend thereof. Thedie plate 212 is further provided with a pair of longitudinal bores 225 (onlyone of which is shown in FIG. 10) radially spaced from the axis 220tby equal distances and each bore 225accommodating one ofa pair of downwardly extending support posts 232 and 234 as shown in FIGS. 8 and 10. Axiallycentered within the die bushing bore 218 for reciprocating movement is a telescopically engagingpunchassembly 238 comprising an inner punch 240 adapted for sliding movement within a longitudinal bore 241 of an outer punch 242, which, inturn, is axially aligned and slidably engaged within the die bushing bore 224.

The lower end of the outer punch 242 is secured within a centrally disposed bore 243 formed. in an upper punch support 248 by a suitable. adhesive, such as the aforementioned Loctite. An annular shoulder 247 formed on the outer punch 242 abuts the upper surface of the upper punch support 248 and aids in the transmission of ,acompacting force, as will be describedhereinafter. The upper punch support 248 has a pair of diametricallyopposed longitudinal bores 264; (only one of which is shown in FIG. 10) whichare radially spaced from the axis 220 by the same distances as the die plate bores 225 to permit a sliding engagement between the upper punch support 248 and. the posts 232 and 234,.and to provide proper alignment of the upper end of the outer punch 242 with the die bushing bore 224, such that the outer punch 242 extends axially upward from the upper punch support 248 to register'with the die bushing bore 224. V v

.Iheinner punch .240 extends from the lower end of the outerpunch 242 and is supported at its lower end by a lower punch support 249 in a centrally disposed bore 251. The interfaces of the inner punch240 andthe lower punch support 249 may be bonded by any suitable adhesive such as the aforementioned Loctite. The lower .19.. punch 240 has an annular shoulder 253 which abuts the upper surface of the lower punch support -249yand functions to aid in transmitting the compacting force from the lower. punch support 249 to compact the powder material-within the die bushing bore 224,-The. lower punch support 249 has a pair of diametrically opposed longitudinal bores-254 (oneof which is shown in FIG. 10-) which are radially spaced from the axis 20 by the'same distances as the die-plate bores 225 and permit-asliding engagement between the lower punch support 249.1 and the posts 232 and 234 so as to align the upper end :of the inner punch 240 with the longitudinal bore 241 of the outer punch 242, such that the inner punch 240 extends-axially upward from thelower punchsupport 249 to register with the longitudinal-bore 241 and extend-in axial alignment with the outer punch 242 into the die bushing bore 224. The outer diameter of the outer punch 242accurately fits the inner diameter of the die bushing bore 224 and together with the inner punch 240. define a die cavity256 (FIG. 7).

The die and punch assembly 200 further comprises a core rod support 258 of a cylindricalshape. The core rod support 258 is provided with a central, partially threaded aperture 260 in which "a core rod insert-. 262 threadedly.

engages. The core rod support 258 isalso provided with a pair of diametrically opposed longitudinal bores 265 ':(one of which isshowninFIG. 10), which are .radially spaced from the axis 220 by the same distances .as'the die plate bores 225. Core rod support. 258- is positioned ata selected distance below the die bushing 222: by means of a sliding engagement between the bores-265-and the support posts 232 and 234. A pair. of. threaded. passages(one of which. is shown at 268 in FIG. 10) radially-extends from the outer periphery of the core rod support 258 and terminate at the longitudinal bores265, the threaded bores 268 accommodating set screws 270. r I

Thecylindrically shaped core rod sup ort zss may be adjusted up and down on the support post's23'2fand 234 at a selected distance from the lower surface of the die bushing 222 and locked in' place by fifieans of thexset screws'270. The inner punch 240 hasalongitudinalbore 272 clo'sely fitting the outerldiameterofa corelrod 274 which is disposed within the innei punch longitudinal bore 272 for relative sliding; movement, such 'thatft'he inner punch '240 slidablyguided' over the .corei odj274 and the inner punch 240 is fr 'e I and dowumove;

inent relative to the core rod 27 4 I 2 r "The 'core' rod 274 is'fixedly ouritedinto the upper uni threaded portion ofdthe core rod support aperture 260 byany suitable adhesive, with thelow erfend ofthejcore rod in abutment with .the core rod insert'jlfil Initial ad justrnent 6f the insert 262 with respect to h'e'upper sur face of the core rod support 258 axially juststhepqsi tionof the" core" rod 274' so that the; 'per end of the core rod 274 may be flush with"the"i1 per 'siir face221 of-tlie die bushing 222. "j With reference to FIGS. 8 and .10, the lowerpunch support 249 is shown' 'as being directly coupled to an ac tuating 'stem" 27 6 byrnea 'ns of a plate member.278 and a pair of threaded fasteners 2801 The plate member 278 has a pair of diametricallyioppQsed bores. -279 (FIG. ;1 which slidablyerigagethe' posts 232 and .234 toguide the plate member 27.8 during,reciprocal movement... thereof. Each threaded'fasten'er 280.,extend's. axially. through a bore 284fin the platemember, 278 an dithreaded ly engages the lower punch support 249 as shown at 28-6. A sleeve member 288 surrounds each fastener 280 with-the upper and lower surfaces of each sleeve member 288 being respectively" in abutment with the lower surfaces of the lower punch support 244 and the. upper surfacejof the plate member 278'."Thus, as the faste ners 280Qare threaded into the ,lowerpiinch support @249,-.,tl 1e .punch support249, and the plate member 278 are fixedlysecuredto one another and reciprocate as a unit under the reciprocating motion of theactuating stem 276. The actuating stern 2 76 isattached to a centrally disposed bore 290 within the plate member 278 by any suitable means such as the adhesive Loctite. Bores 291 (FIG. 10) disposed in the lower punch support 249 slidably receive the outer periphery of the sleevemembers 288. As can best be seen in FIG. 8, the fasteners 280 are angularly displaced from the support posts 232 and 234.

.The plate member 278 is provided with diametrically opposed threaded bores 294 (FIGS. 7 and 9) which are angularly. spaced from the support posts 232 and 234.

Threaded adjustable abutment members 296, one of which is illustrated in FIGS. 7 and 9, are threaded into the bores 294 and extend axially upwardly through enlarged bores 298 and 300 respectively formed in the core rod support 258 and the lower punch support 249. The abutment members 296 are adapted to abut the lower surface of the upper punch support 248 when the actuating stem 276 moves the plate member 278 in an upwardly direction to thereby cause movement of the outer punch 242 into the die. bushing bore 224 as shown in FIG. 9.

The upper punch support 248 also has diametrically opposed .threaded bores 302 each of which threadedly receives a second mechanical abutment member 304. The mechanical abutment members 304 extend axially downwardly from the upper support member 248 and through diametrically. opposed bores 306, 308 and 310, respectively, foundin the lower punch support 249, the core rod support 258 and the plate member 278. Each abut-v ment member 304 has an enlarged end portion 312 which is adapted. to abut the lower surface of the plate member 278/(as shown in FIG. 7) when the actuating stem 276. -is .moved downwardly so as to impart a corresponding downwardmo-vement of the outer punch 242 and withdraw the outer punch 242 downwardly in the die bushing bore .224. 1

A spring- 314 is disposed around each abutment member 312 with the opposite ends respectively in abutment with the underside of the upperpunch support 248 and the upper surface of the plate member 278 to bias the two components away from each other. and to maintain theupper. punch support 248 in a predetermined position rel-afiVfi to. the-die bushing bore 224 and the platemember 2 7 8. ;when,the die and punch assembly is in the filled position i-llustrated in FIG. 7 'mAs hereinbefore mentioned, a typical compacting cycle includescaapowder filling step, a-compacting step and an ejection stepgwAs-showni in FIG. -'7, the filling step comprises :positioning a hopper 316:over the die plate 212 completely encompassingthe die bushing 222 to fill-the diecavit-y-e256. defined-by the die cavity bore 224 and upper'ends of the inneniand outer punches. The punches areslightly displaceddownwardly' under the action of the aotuating;,stem 276. to insure a complete filling of the die cavity .1256. ,After, the filling step and with, the punches positioned asshown in FIG.. 1, the hopper 316 is removed, by ,means'not shown, and the upper surface 221 of the-die bushing 222 is wiped clean of any excess powder.- As shown in FIG. 9, an anvil 318 is transferred over thefilled diecavity 256 and clamped into position. The upperends 320 -(FIG.-'7) of the abutment members 296 carried by the plate member 278 are normally displaced below the lower surface of the upper punch support 248 by a predetermined distance, which is dependent upon the amount of compaction desired. Initially, when the act-natingstem .276 .is. actuated to move in an upwardly direction to cause compaction of the powder material within the die cavity256, only the innerpunch 240 will move upwardly intothe die bushing bore 224. After the actuating stem 276'has moved upwardly. a suificient distance, theupper;v ends 320 of the-mechanical abutment members- 296 willgengage the underside of the upper punch support 248, at which time 'both the upper and lower punch supports and their associated punches will move together. asa unit to compactthe powder contained within the die cavity 256 against the anvil 318 to .form a compacted finished article 322 having a flanged button shape ('FIG. 9).

After compaction of the article 322, the compacting pressure is relieved by a slight downward movement of the punches and the anvil 318 is removed from over the die cavity 256. The inner and outer punches 240 and 242 are then preferably displaced upwardly so that they eject the finished article 322 which may be picked up by any suitable means such as the vacuum pick-up described in the aforementioned patents, and removed from the die cavity 256 to be deposited in any suitable container.

After ejection of the compacted article 322, the actuating stem 27 6 moves downwardly withdrawing only the inner punches 242 downwardly in the die bushing bore 224, while the bias of the springs 3-14 maintains the inner punch 240 in upward position with respect to the die bushing bore 256 until the lower ends 312 of the abutment members 304 carried by the upper punch support 248 are engaged by the lower surface of the plate member 278, as shown in FIG. 7, at which time both the upper and lower punches 240 and 242 move downwardly together as a unit to the fill position, wherein the compacting cycle may be repeated.

It can thus be seen that the present invention provides a die and punch assembly having an improved arrangement for a die and punch assembly for producing shaped articles, such as cup-shaped and flanged button-shaped articles, from a powdered material.

Although only two embodiments of the present invention have been disclosed, it will be apparent to those skilled in the art of powder compacting presses that other embodiments may be had all coming within the spirit of the invention and the scope of the appended claims.

What is claimed is as follows:

1. -An apparatus for making a compacted powdered article comprising: a die plate having at least one die cavity, means for dispensing a powdered material into said die cavity, an upper and a lower compacting means adapted to be aligned with said die cavity and disposed for relative movement toward and away from each other to compact said powdered material within said die cavity, said lower compacting means comprising an outer punch and an inner punch slidingly arranged one within the other for extension into said die cavity, first support means spaced below said die cavity and supporting said outer punch for movement within said die cavity, second support means spaced below said first support means and supporting said inner punch for movement within said outer punch, actuating means operatively coupled to one of said support means to impart a recprocating motion thereto, said actuating means having first adjustable abutment means engaging the other of said support means to move both of said support means in a first direction together as a unit after said actuating means moves said one support means in said first direction for a distance depending from the adjustment of said first abutment means; and second adjustable abutment means carried by said other support means for engaging said actuating means when said actuating means is moved in an opposite direction to move both of said support means in said opposite direction together as a unit after said actuating means moves said one support means in said opposite direction for a distance depending from the adjustment of said second abutment means.

2. The apparatus defined in claim 1 wherein said actuating means is disposed below said second support means, and further comprising resilient means provided between said actuating means and said other support means to maintain said other support means in position relative to said actuating means when said other support means is not engaged by said abutment means carried by said actu- 3. The apparatus defined in claim 2 wherein said 'reating means. silient means comprises a spring disposed between said actuating means and said other support means.

4. The apparatus defined in claim 1 further comprising post means; said first and said second support means each comprising a support plate slidably mounted to said post means for reciprocal movement toward and away from said die cavity, said actuating means having an enlarged end portion and disposed below said second support plate, said enlarged portion of said actuating means slidably engaging said post means.

5. The apparatus defined in claim 1 further comprising at least one core rod disposed in said inner punch for the provision of at least one core hole in said compacted article.

6. The apparatus defined in claim 1 further comprising a longitudinal bore extending in said inner punch from one end to the other end thereof, a core rod slidably and snuggly disposed within said punch longitudinal bore and having an end projecting through the lower end of said inner punch and said second support means; a core rod support positioned between said second support means and said actuating means and having means for mounting the lower end of said core rod on said core rod support for axial alignment with said inner punch bore.

7. An apparatus for making a compacted powdered article, comprising: a die plate having at least one die cavity, means for dispensing a powdered material into said die cavity, an upper and a lower compacting means adapted to be aligned with said die cavity and disposed for relative movement toward and away from each other to compact said powdered material into a finished article within said die cavity, post means carried by said die plate and extending downwardly therefrom, said lower compacting means comprising an outer punch and an inner punch slidingly arranged one within the other for telescopic extension into said die cavity, a first punch support spaced below said die cavity and connected to said outer punch and engaging said post means for reciprocating movementrelative to said die cavity, a second punch support spaced below said first punch support and connected to said inner punch and engaging said post means for reciprocatin'g movement relative to said die cavity, reciprocating means positioned below said second punch support and operatively connected to said first punch support for reciprocating said first punch support relative to said die cavity, said reciprocating means having an adjustable abutment means for engaging said second punch support whereby said reciprocating means and said punch supports move in an upwardly direction toward said die cavity, together as a unit, after said reciprocating means moves said first punch support in an upwardly direction of a distance depending from the adjustment of said adjustable abutment means. i 8. The apparatus defined in claim 7, further comprising second adjustable abutment means carried by said second punch support for engagement by said reciprocating means to move both said punch supports in a downwardly direction away from said die cavity after said reciprocating means has moved said first punch support in said downwardly direction of a distance depending from the adjustment of said second adjustable abutment means.

9. The apparatus defined in claim 8 wherein said reciprocating means slidably engages said post means, and further comprising resilient means provided between said rec procating means and said second punch support to mamtam said second punch support in position relative to said reciprocating means when said second punch support 1s not engaged by either of said adjustable abutment means.

10. The apparatus defined in claim 9 further comprising a longitudinal bore extending in said inner punch from one end to the other end thereof, a core rod slidably and snuggly disposed within said inner punch longitudinal bore and having an end projecting through the lower end of said inner punch and said second punch support, a core rod support fixedly mounted to said post means below said second punch support and above said reciprocating means and having means for mounting said core rod on 13 said core rod support for axial alignment with said inner punch bore.

11. An apparatus for making a compacted powdered article comprising: a die plate having at least one die cavity, means for dispensing a powdered material into said die cavity, an upper and lower compacting means adapted to be aligned with said die cavity and disposed for relative movement toward and away from each other to compact said powdered material into a finished article within said die cavity, post means carried by said die plate and extending downwardly therefrom, said lower compacting means comprising: an outer punch and an inner punch slidingly arranged one Within the other for telescopic extension into said die cavity, a first punch support spaced below said die cavity and connected to said outer punch and engaging said post means for reciprocating movement relative to said die cavity, a second punch support spaced below said first punch support and connected to said inner punch and engaging said post means for reciprocating movement relative to said die cavity, reciprocating means positioned below said second punch support and operatively connected to said second punch support for reciprocating said second support relative to said die cavity, said reciprocating means having an adjustable abutment member for engaging said first punch support whereby said reciprocating means and said punch supports move in an upwardly direction towards said die cavity together as a unit after said reciprocating means moves said second punch support in an upwardly direction of a distance depending from the adjustment of said abutment member.

12. The apparatus defined in claim 11 further comprising a second adjustable abutment member carried by said first punch support engageable by said reciprocating means to move 'both said punch supports in a downwardly direction away from said die cavity after said reciprocating means has moved said second punch support in said downwardly direction of a distance depending from the adjustment of said second abutment member.

13. The apparatus defined in claim 12 wherein said reciprocating means slidably engages said post means, and further comprising resilient means provided between said 14 reciprocating means and said first punch support to maintain said first punch support in position relative to said die cavity when said first punch support is not engaged by either of said adjustable abutment members.

14. The apparatus defined in claim 13, further comprising a longitudinal bore extending in said inner punch from one end to the other end thereof, a core rod slidably and snuggly disposed within said inner punch longitudinal bore and having disposed within said inner punch longitudinal bore and having an end projecting through the lower end of said inner punch longitudinal bore and said second punch support, and a core rod support fixedly mounted to said post means below said second punch support and above said reciprocating means and having means for mounting said core rod on said core rod support for axial alignment with said inner punch bore.

References Cited UNITED STATES PATENTS 2,810,929 10/1957 Willi 18--16.7 2,821,748 2/ 1958 Willi 18-16.7 2,883,703 4/1959 Frank 1816.7 3,154,812. 11/1964 Haller 18-16.7 3,168,759 2/1965 Johannigman 18-16.7 3,172,156 3/1965 Belden 1816.7 3,337,916 8/1967 Smith 1816.7 3,460,202 8/1969 Graf et al 18-16.7 X 3,464,089 9/1969 Smith 18-16.7 3,524,220 8/ 1970 Davison 18--16.7 3,561,056 2/1971 Smith et al 18-16.7

FOREIGN PATENTS 663,040 12/ 1951 Great Britain 18--16.7

OTHER REFERENCES Smith 3574892, April 1971.

J. HOWARD FLINT, J R, Primary Examiner US. Cl. X.R.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3733154 *Aug 17, 1971May 15, 1973Wolverine PentronixDeflection compensation system for press
US3741697 *Feb 2, 1972Jun 26, 1973Wolverine PentronixRemote control system for powder compacting presses
US3999922 *Apr 16, 1975Dec 28, 1976Yasuo ShimadaRotary tableting machine
US4053267 *Oct 22, 1976Oct 11, 1977Wolverine Aluminum CorporationDie and punch assembly for compacting powder material
US4153399 *Sep 8, 1977May 8, 1979Ptx-Pentronix, Inc.Multiple punch tool set for powder compacting press
US4450127 *Sep 20, 1982May 22, 1984Ptx Pentronix, Inc.Method for compacting powder material with adjustable die and punch assembly
US4456445 *Sep 19, 1983Jun 26, 1984Ptx-Pentronix, Inc.Mounting structure for die, punch and core rod assembly for compacting powder material
US4865789 *Nov 14, 1983Sep 12, 1989Akzo NvMethod for making porous structures
US5326242 *Aug 9, 1991Jul 5, 1994Yoshizuka Seiki Co., Ltd.Powder molding press
US8312612 *Jun 9, 2010Nov 20, 2012Blue Sky Vision Partners, LlcRefurbished punch tip and method for manufacture and refurbishing
US20100239698 *Jun 9, 2010Sep 23, 2010Luka GakovicRefurbished punch tip and method for manufacture and refurbishing
Classifications
U.S. Classification425/78, 425/345, 425/405.1, 425/414
International ClassificationB30B11/02, B22F3/035, B22F3/02, B22F3/03
Cooperative ClassificationB30B11/027
European ClassificationB30B11/02D