US3344213A

US3344213A - Powder compacting method

Info

Publication number: US3344213A
Authority: US
Priority date: 1965-04-23
Publication date: 1967-09-26
Anticipated expiration: 1984-09-26

Description

Sept. 26, 1967 P. vlNsoN POWDER COMPACTING METHOD Filed Feb. 24, 1966 5 Sheets-Sheet l Armar/(6 Sept. 26, 1967 P, VINSQN 3,344,213

POWDER COMPACTING METHOD Filed Feb. 24, 1966 5 Sheets-Sheef. 2

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INVENTOR. @a4 -z//ff/sa/z/ Zz #f5/Mfg.

Fraz/vins Sept 26, 1967 P. vlNsoN 3,344,213

POWDER COMPACTING METHOD Filed Feb. 24, 1966 5 Sheets-Sheet 5 By #www Sept. 26, 1967 P. vlNsoN POWDER COMPACTING METHOD 5 Sheets-Sheet 4 Filed Feb. 24, 1966 @Mig M if A .xol rl .M w. Zw W ZQf// Vn 6 www wawa Sept. 26, 1967 P. vlNsoN 3,344,213

POWDER COMPACTING METHOD Filed Feb. 24, 1966 5 Sheets-Sheet 5 Ww KM@ United States Patent O 3,344,2l3 WBER CGMPASTNG METHOD Paul Vinson, Costa Mesa, Calif., assigner to Pentrnnix, inc., a corporation of Michigan Filed Feb. 24, 196e, Ser. No. 529,734 6 Claims. (Cl. 264-39) ABSTRACT 0l? THE DISCLOSURE the punches with coaxial core rods movable independently from the punches.

The present application is a continuation in part of serial number 450,427, filed April 23, 1965, and now abandoned.

The invention in the present application relates to a new and improved automatic powder compacting method. The method of the present application is for the purpose of manufacturing cores or beads of ferrite or glass or any other powdered metal or comparable substance. The primary purpose of the method is the manufacture of memory cores which are normally toroidal, pills, such as pharmaceutical pills, balls for ball point pens, porous bearings and bushings, and the like. Memory cores are of course widely used in computers and related apparatus. As stated, memory cores and porous bearings and bushings are normally toroidal, although pharmaceutical pills may be in the form of tablets, such as aspirin tablets, and balls for ball point pens are of course spherical.

Ferrite cores, by way of an example, may be from approximately .005 to .015 inch in thickness and the accuracy of the dimensions must be held to 1/10 of a thousandth of an inch. Balls for ball point pens may be in the same order of dimensions, and also require great accurcay in manufacturing. Pharmaceutical pills do not, of course, have to have comparable accuracy. In the manufacture of the ferrite cores for use in memory devices, the density of the cores must also be held accurate thereby making it necessary that the lill or the amount of powder in each die cavity of a compacting press be maintained within very close limits. The resulting density of all cores must be the same, that is, it must be uniform and accordingly, the compressing of the powdered material must be exact and repetitively constant. lf these dimensional and density factors are not held within close tolerances the readout level from the cores in a memory stack would not be substantially constant from core to core and the cores would not then serve their purpose. To realized the dimensional accuracy referred to in the foregoing, it is necessary that the press used for practicing the method of the invention be capable of accurate adjustments of movements of certain parts within at least 50 millionths of an inch. The powder is compressed by way of punches which control the fill of the die cavities and the thickness to which the cores are compressed. in a machine for practicing the method according to the present invention the adjustment of the movements of these parts is accurate to within a millionth of an inch. One of the primary objects of the invention is consequently to make possible this degree of accuracy whereby the dimensions and density of the 3,344,213 Patented Sept. Z, i957 ICC manufactured article is controllable with a great degree of accuracy.

A machine for practicing the method according to the present invention has many novel characteristics and advantages rendering it suitable for fulfilling many objectives in addition to the foregoing. An exemplary form of a machine for practicing the method of the invention which has been reduced to practice is capable of producing approximately eight hundred cores or pills per minute and its production rate can readily be increased to approximately sixteen hundred per minute. The machine referred to is fully automatic and discharges the finished units into separate vials or bottles. In the preferred exemplary form the machine is motor driven. The cores or pills are formed in a multi-cavity die. The cavities are atuomatically and accurately lled with powder; the powder is automatically pressed or compacted; the iinished articles are automatically ejected from the die and are picked up, discharged and delivered into the vials or bottles.

In the preferred exemplary form of a machine to practice the present invention the punches move upwardly in the die cavities for compacting the powder. A iiipper assembly is provided which is movable transversely over the die and carries an anvil which is positionable over the die cavities. The flipper assembly also includes a secondary powder hopper in the form of a split ball which is also positionable over the die cavities for providing an overiill of powder in the cavities, the excess powder being expelled back into the hopper as will be explained hereinafter. Additionally, the flipper carries a vacuum pickup means for picking up the finished articles, i.e., cores, pills, or the like, and transferring t-hem to a discharge station for ejection through tubes into the bottles or vials referred to above. Another object of the invention, consequently, is to provide for positioning the anvil, the secondary hopper and the vacuum pickup above the die cavities.

The secondary hopper is connected through a tube to a main hopper in the form of a bottle or the like containing powder to be compacted. Additionally, an object of the invention is to provide brushing olir the surface of the anvil and for the edge surfaces of the Teiion ball forming the secondary hopper wiping the surface of the die on each operation of the flipper.

A further object of the invention is to provide an improved method for obtaining the desired accuracy in the adjustment of and movement of the punches and core rods for effecting the fill of the die cavities and compacting the powder.

An additional object is to provide for accuracy of operation and maintenance of the desired accuracy in applications where toroidal articles are produced by reciprocating punches in the form -of sleeves having central bores with core rods operating in the bores independently from said core rods. A further object is to realize the desired accuracy' by supporting the punches and core rods by means of a holder having circularly arranged radial slots for these elements allowing them to float radially, but containing them axially or vertically and by utilizing the internal surface of the die cavities or bores for positioning the punches and the internal surface of the bores in the punches for in turn positioning the core rods. Another object is to provide accurate adjusting of the strokes and operational positions of the core rod holder and punch holder.

Further objects and additional advantages of the invention will become apparent from the following detailed description when read in conjunction with the attached drawings wherein:

FIGURE 1 is a plan View of an example of a preferred 3 embodiment of a machine for practicing the method of the invention;

FIGURE 2 is a side elevational view thereof;

FIGURE 3 is a sectional view thereof taken substantially along line 3 3 of FIGURE 1;

FIGURE 4 is a sectional view of a portion thereof taken along line 4 4 of FIGURE 3;

FIGURE 5 is a sectional view thereof taken along line 5 5 of FIGURE 3;

FIGURE 6 is a sectional view of a portion thereof taken along the line 6 6 of FIGURE 3;

FIGURE 7 is a sectional view of a portion thereof taken along line 7 7 of FIGURE 3.

FIGURE S is a sectional View of a portion thereof taken along line 8 8 of FIGURE 5;

FIGURE 9 is an enlarged sectional view of the tooling capsule of the example of a preferred embodiment of the invention shown in the die cavity fill position;

FIGURE 10 is a partially enlarged sectional view of the tooling capsule shown in the press position;

FIGURE 11 is a partial enlarged sectional view of the tooling capsule shown in the eject position;

FIGURE l2 is an enlarged detail View, partly in section, of the part of the flipper carrying the anvil and the vacuum pickup;

FIGURE 13 is a plan view of the die as seen from line 13-13 of FIGURE 9;

FIGURE 14 is a view of the top of the tool holding capsule as seen from line 14-14 of FIGURE 9;

FIGURE 15 is an axial view of the cam shaft showing the contours of all the cams;

FIGURE 16 is a greatly enlarged partial sectional detail view showing the lling operation of a die cavity;

FIGURE 17 is an enlarged partial sectional view of a detail similar to FIGURE 16, but illustrating the press operation; and

FIGURE 18 is an enlarged partial sectional view showing the eject operation with the vacuum pickup in position.

GENERAL ORGANIZATION OF THE MACHINE The general organization of the illustrated exemplary embodiment of a machine to practice the method according to the invention will be described first and the various parts and components will subsequently be described in detail, proceeding from the input drive end to the tool holding capsule die and flipper actuation.

Referring to FIGURES 1 and 2 of the drawings, a preferred exemplary embodiment of a machine to practice the method according to the invention comprises a substantially rectangular base 10 on which the machine is mounted, and a housing 11 enclosing various components of the machine as Will be hereinafter described. A variable speed electric motor 13 is provided with an output shaft 14 for driving a shaft 15 through a coupling 16 for furnishing the power means for effecting the lling, pressing, ejecting and vacuum pickup operations of the machine. The motor 13 is mounted in a saddle 20 having upright legs 21 and 22 with

feet

23 and 24 mounted on

spacers

27 and 28 on the base 10 of the machine. Numeral 30 designates a housing forming a part of the motor 13 which contains a reduction gear train through which the shaft 15 is driven.

On one end of the shaft 15, at the opposite end of the housing L11, is a hand wheel 32 by means of which the shaft 15 can be rotated by hand.

A primary hopper 35 in the form of a funnel or a bottle contains the powder to be compacted into nished articles. From the bottom of the primary hopper leads a flexible tube 36 which connects to the secondary hopper which operates to ll the die cavities, as will be described hereinafter. The primary hopper 35 is supported in a exible clamp 38 attached to the upper end of an upright 39 having a base 40 attached to the top of housing 11 by bolts, as shown at 41 and 42.

Within the housing 11, and shown in broken lines in FIGURE 1, there is a pulley 45 keyed on the shaft I5. This pulley drives another pulley 46 by means of a belt 47. The pulley 46 is in turn keyed on a shaft 48 sultably mounted and journaled within the housing 11. Mounted on the shaft 43 there is a bevel gear 50 which meshes with another bevel gear 51 keyed on a shaft 52 which drives a rotary brush 53. The bristles of the brush 53 eX- tend upwardly and the brush is positioned adjacent to the ipper assembly, designated generally at 56, which 1s mounted on top of the housing 11. The flipper assembly will be described in detail hereinafter and for the present, it is sufficient to indicate that it is positionable over the die having the die cavities in which the powder is compacted. The position of the ipper assembly 56 may be observed in the cross-sectional views of FIGURES 3 and 5, the die being shown generally at 58 in FIGURE 5.

Referring again to FIGURES 1 and 2, the flipper assembly can be seen to include a body member 6) rotatable in a horizontal plane, pivotally supporting anvil holding member 62 and a support member or arm 63 for the secondary hopper. Between these members is disposed the vacuum pickup member or head 65. The anvil holder member 62 carries an anvil 335 (best seen in FIGURES 10 and 12) and the anvil may be moved over brush 53 so that any powder adhering to the anvil is brushed off.

Numeral 67 designates an arm member which cooperates with a cam surface 69 at the end of the anvil holder 62 for extending the anvil toward the die cavities as will be explained hereinafter in further details.

The vacuum pickup is connected by means of a exible tube 76 to a controlled source of vacuum, which may be of any suitable type, as designated by numeral 78. The iinished articles, after having been pressed from the powder and ejected, are picked up by the vacuum pickup 65 and are released over a member having a group of holes arranged in a circle corresponding to the cavities or bores in the die 58 as will be described in further details hereinafter. The compacted iinished articles, whether toroidal cores, tablets, or balls, when released drop into these holes to which are connected a plurality of tubes as shown at S0 which lead to and into separate individual vials or bottles into which the inished articles are delivered.

Referring now to FIGURES 3, 4, and 5, it can be seen that a tooling capsule 75, best seen in FIGURE 5, comprises a rod or stem which carries the punches, and a sleeve 86 which carries the core rods. The rod or stem 85 is actuatable by an assembly of cams designated generally at 90 and disposed on the cam shaft 15. These cams operate a cone 92 forming part of a lever assembly designated generally at 93. The sleeve 86, carrying the core rods, is actuatable by a separate cam designated at 97 (see FIGURE 7) which actuates a lever assembly designated generally at 98.

The iiipper assembly 56, FIG. 3 is actuated by a separate cam designated at 101, FIG. 6 which actuates a lever and slide assembly designated generally at 103.

DETAILED DESCRIPTION OF THE MACHINE Actuatz'on of the tooling capsule As explained in the foregoing, the machine for practicing the invention provides for a very accurate adjustment of the positioning of the parts constituting the tooling capsule in order to accurately adjust the ll of the cavities in the die and the pressing of the powder, i.e., the thickness to which the powder is pressed or compacted. The actuating mechanism for these parts, as shown in detail in FIGURES 3 to 8, is driven by the shaft 15 extending transversely through the housing 11, as best seen in FIGURE 3, being journaled therein by means of bushings and 111 fitting appropriate bores disposed in the walls of the housing 11. The housing 11 has a downwardly extending internal web 113 having a bore within which is a bushing 114 in which the shaft 15 is additionally joumaled. The shaft is threaded with a 40 pitch micrometer thread as designed at y117. On the shaft are mounted three cams, as designated at '121, 122, and 123, which constitute respectively the press earn, the ll cam and the eject cam. As shown in FIGURE l5 which is an end view in section of the shaft 15 enabling the cam contours to be observed, the shaft 15 has key ways such as shown at 127, and the cams are keyed to the shaft by keys 128 so that they can slide along it yaxially but are positively driven rotationally by shaft 15. The peripheries of the cams are beveled as shown in FIGURE 3, and the peripheral surfaces of the cams engage with a tapered cone 92 forming part of the lever actuating mechanism for the rod or stem of the tooling capsule. The lever actuating assembly 93 as shown in FIGURES 4 and 5, comprises a lever in the form of a frame, as generally designated at 139. This frame-like lever has an opening 1311 `and is provided with extending stems or

trunnions

133 and 134 received and journaled in

bores

135 and 136 formed in integral web portions of the housing 11, as designated at and 141. A bushing 142 is disposed in an appropriate bore in a portion of the frame-like lever 139 for supporting the stem or trunnion i133. The frame-like lever 130 is further provided with integral

bifurcated legs

146 and 147 forming a yoke affording a journaled support for both ends of the cone 92 rotatably mounted between the legs. The axis of the cone 92 is parallel to the axis of the shaft 15, and its periphery has a taper which for example may be of the order of one degree.

The cone 92 (FIGURE 3) has a threaded bore 150 in its left end, as seen in the drawing, and a tapered counterbore 151. Fitting therein is the threaded end portion of an arbor 153 having a tapered portion 152 and a cylindrical portion 154 journaled in a bushing 156 in a bore in the leg `146. At the other end of the cone 92 there is an arbor having a hexagonal head 161. The arbor extends into the end of the cone 92 and through a bushing 162 in a bore in the end of the leg 147 of frame-like lever 130. This leg also has a counterbore 164 housing a bearing 165 through which the arbor 160 extends. The mountings for the cone 92 are such that it is freely rotatable when engaged by one of the

rotating cams

1211, 122, or 123.

Disposed adjacent to each of the cams, 121, 122 and 123 for holding them in position are knurled nuts, designated and 171 for cam 121, 172 and \173 for

cam

122, and and 176 for cam 123. These knurled nuts thread upon thread 117 on cam shaft 15 and are provided with circumferentially arranged spaced radial holes or bores whereby they may radially be rotated small angular amounts. By means of rotating these nuts the cams may be adjustably displaced axially along the cam shaft 15 whereby precise Vadjustments of the tooling are realized as will be described more in detail presently.

The lever member 139 of the lever actuating assembly 93 is connected to the actuating stem 85 of the punch holding member of the tooling capsule 75 by way of a knuckle joint shown generally at in FIGURES 5 and 8. The lever member 13G has an end portion 131 provided with extending

legs

183 and 184 forming a yoke. These legs, as best seen in FIGURE 8, have bores in them in which are bushings 1&6 and 187 and disposed transversely through these bushings is a pin I19t?. Journaled on this shaft is a knuckle joint member 191 having projecting legs 192 and 193 forming a yoke. A connecting rod or member 195 is connected to the stern 35 by having on its upper end an Mial bore 194 receiving the lower end of stem 85 immobilized therein by means such as set screw 197. The other end 195 of connecting rod 195 is positioned between legs 192 4and 193 of knuckle joint member 191, these parts being connected by a shaft or pin 200 passing through appropriately aligned bores in the legs and in end 196 of the connecting rod. The connecting rod E 195 is guided by a bushing 291 in a bore in a transverse web 203 formed within the housing 11.

On the ends of the pin are

collars

205 and 206 having

radial projecting pins

208 and 209 which fit into the ends of

coil springs

211 and 212, the other ends of which are received in

recesses

214 and 215 in the supporting web 203. Consequently, when the right end of lever '130, as seen in FIGURE 5, moves upwardly the

springs

211 and 212 are compressed and serve to stabilize and regulate the lever operation and the movement of the actuating rod or stem 85.

As will be described presently, the stern 85 moves the punches that control the filling and pressing of the powder. Extreme accuracy of positioning the punches for filling the die cavities is required and extreme accuracy in the pressing movement of the punches for compacting the powder is necessary in order that the finished articles be pressed or compacted to the required thickness. These adjustments are realized by adjusting the

cams

121 and 122 and 123 along the threaded shaft 15. Detailed description of these adjustments will be given after the tooling capsule has been described in detail.

The sleeve 86 as shown in FIGURES 5 and 9 carries the core rods which fit in axial bores in the punches as will be described presently. This sleeve is -actuated by a separate cam which is the cam 97 shown in FIGURES 3, 7, and 15.

Between the cam 97, as shown in FIGURE 3, and the web 113 is a bushing 229. Between the cam 97 and cam 101 is a washer 221, and on the opposite side of the cam 101 is another washer 222. As shown in FIGURE 7, -a roller cam follower 225 which engages the cam 97 is mounted on the end of an arm 226 attached to a transverse pivot pin 228. As shown in FIGURE 5, a support bracket 239 attached inside of the housing 11 by screws such as shown at 231, is provided with a bore in which the transverse pivot pin 228 is journaled. Bracket 230 is substantially in the form of a yoke and it also supports, mounted on the pivot pin 228 between the legs of the yoke, an actuating lever arm 233 acting against a coil spring 235, the other end of which is received in a -recess 236 formed below the top of the housing 11. The end of the lever 233 is bifurcated so as to form a yoke designated generally by numeral 240. The yoke 240 engages the barrel part of a nut or threaded collar 242 having knurled

flanges

243 and 244 as may best be seen in the enlarged view of FIGURE 9. The sleeve 86 of the tooling capsule 75 is threaded at its lower end 250. Threaded onto this end 250 is an internally and externally threaded sleeve 251 having a nut head 252 formed at its lower end. The threaded collar 242 is threaded onto the external threads on the sleeve 251 and its position thereon may be set by a lock nut 254.

As may be seen, the assembly just described provides for a fine relative adjustment of the position of the sleeve 86 that actuates the core rods relative to the position of the actuating lever mechanism 98 including the lever arm 233 and the yoke 240 at the end thereof. The intern-al and external threads of the sleeve 251 are of dilerent pitch. Therefore, by adjusting the nut head 252 and sleeve 251 to move it in one direction while adjusting the threaded collar 242 to move it in the opposite direction a very fine precision adjustment can be made in the vertical position of the actuating sleeve 86, controlling in turn the position of the core rods, relative to the actuating mechanism and cam 97. Or stating it another way, the instantaneous position of the core rods can be very precisely adjusted for any position in which the cam 97 is in at a given time.

Tooling capsule The tooling capsule 75 is best seen fully in cross-section in FIGURE 9 and portions thereof are shown in FIGURES 10 and 11, and also in FIGURES 13 and 14. Referring now more particularly to FIGURES 9, 10 and 11, the body of the housing 11 has a bore 295 in which it receives the tooling capsule and the tool holders. Within the bore 295 is a cylindrical member 297 having a bore 29S in its bottom. A second cylindrical member 300 is disposed within the cylindrical member 297. The cylindrical member 300 is open at its bottom end and has an upper closed end provided with a group of eight bores or openings 301 to accommodate the punches, shown at 30S, which reciprocably move through these bores. The punches 308 are carried in a tool holder in the form of an integral enlarged head 303 at the end of the rod or stem 85. The head 303 is adapted to reciprocably move in the inside, or bore 305, of the cylindrical member 300. The head 303 has eight angularly spaced radial slots 307 best seen in FIGURE 14. There are eight punches 30S corresponding to the number of slots 307 in the head 303. Each punch has an enlarged circular head as shown at 309 in FIGURES 9 and 14 of a thickness to be received in an annular groove 310 in head 303. Each punch has a part of decreased diameter 311, of a size to be received in one of the radial slots 307, and an upper portion 312 of still decreased diameter which performs the punching operation. This portion 312 of each punch is of a size to t snugly into one of the cavities or bores 314 in the die 58. In the example of the invention as shown, there are eight punches corresponding to the number of cavities or bores 312 in die 58, as best seen in FIGURE 13. The die 58 is circular and may be made of suitable material for this porpose such as hardened tool steel or tungsten carbide which may be substantially the same as the material of the punches. The entrances to the die cavities or bores 314 are slightly chamfered or radiused as shown at 315. At the bottom of the die there is an extending integral flange or shoulder 316 and the die as a whole lits into a corresponding bore and counterbore as shown in the top wall portion of the housing 11.

Each of the punches 303 is provided with a longitudinal bore 313 of a size to snugly receive a core rod, designated generally at 320. The upper end of the sleeve S6 forms a tool holder within the tooling capsule for the core rods by being provided with an annular groove 321 and a group of eight angularly spaced radial slots designated generally at 322, corresponding to the slots in the head 303 of rod or stem 85. The core rods 320 are provided with enlarged heads 323 which are received in the annular groove 321 and with yreduced diameter cylindrical portions 325 which are held in slots 322. The core rods are further provided with integral further reduced diameter portions 326 adapted to extend upwardly through the bores 313 in the upper portions 312 of the punches 308. This construction can be observed more clearly in the enlarged views of FIGURES 16, 17 and 18.

From the foregoing those skilled in the art will observe that both the punches and core rods are free to oat radially in their tool holders, but they are contained axially. The punches are guided axially by the internal diameter of the cavities or bores 314 in the die S. The core rod ends 326 are guided by the internal diameter of the bores in the upper parts 312 of the punches 308. This manner of holding and mounting the tools whereby radial float is permitted and the tools are contained axially as described makes it possible to realize the degree of accuracy which is necessary in the adjustments and movements as has been described in the foregoing. The ts respectively between the outer diameter of the punches 308 and the inner diameter of the bores 314 of the die cavities and between the youter diameter of the core rod ends 326 and the inner diameter of the bores 313 in the punches are effected within close tolerances and with great precision.

The consecutive operations effected by the tooling capsule and the respective positions of the punches and core rods while effecting such operations are illustrated in FIG- URES 9, 1() and 11 showing respectively the fill, press and eject positions of lthe tool holders and tools in the tooling capsule 75. As will be observed in FIGURE 9 and the enlarged view of FIGURE 16, the punches 308 and core rod ends 326 have been retracted for purposes of lling the die cavities or bores 314i. The position to which the punches are retracted is determined with extreme accuracy by prior adjustment as will be described hereinafter.

FIGURE 10 and the enlarged View of FIGURE 17 illustrate the press position. In this position the bottom face 37S of the anvil 335 is positioned over the die 53. The ends 326 of the core rods have been moved upwardly against the bottom face 378 of the anvil 335 and the punch end portions 312 have moved up to compact or press the powder in each die 314 into a toroidal shaped article as designated at 336 in FIGURE 17.

FIGURES 11 and 18 show the eject position wherein the punch end portions 312 have been moved up with their end faces substantially level with the ends of each die cavity 314 for ejecting the nished articles 336 from the die cavities. In this eject position, the vacuum pickup head or member is over the die 58 in a position to pickup the compacted articles 336 for transfer to a discharge station as will be explained hereinafter in further details relative to the description of the llipper assembly and its operation.

The actuation of the fpper assembly The ipper assembly, designated generally by numeral 56, is actuated from cam 101 (FIGURE 3) having a contour as shown in FIGURES 6 and 15. The cam 101, as best seen in FIGURE 6, actuates a lever member 260 which is in the form of a cam follower mounted on a pivot bolt 261 within the housing 11. The lower end of the cam follower member 260 acts against a coil spring 262 the end of which engages a spring holder 264 which abuts against a sidewall of the housing 11.

As shown in FIGURE 3, in the top plate of the housing 11 is provided a recess 270 having a bottom surface. Recess 270 is in turn provided with a transversely disposed lower recess 271. These recesses are covered by a cover plate 273. The end `of the cam follower member 260 engages in an opening 275 in a slide member 276 that slides in the transverse lower recess 271. The slide member 276 has an extending pin 278 (FIGURE 3) that engages in a bore 279 in the end of a lever 280 pivoted at an intermediate point by Way of a pivot pin 281 extending into a bore 282 in the bottom of the recess 270. In the other end of the lever member 280 is a bore 235 which receives a pin 286 the upper end of which is threaded at head 237 for eixing radially to a side part or portion of the flipper member 60. As may be observed, the actuating eect of the cam 101 is to operate the lever 260 which by Way of the slide 276 and lever 280 rotates the flipper member 60 angularly through its various positions as shown in FIGURES 9, 10, l1 and 12. The details of the ilipper assembly will be described hereinafter.

The flipper assembly The flipper assembly may be seen in FIGURES 1, 2, 3, and 5 and parts of it in FIGURES 9, 10, and 11 and in the enlarged views of FIGURES 12, 16, and 17 and 18. As best seen in FIGURES 3 and 5, the lipper body 60 has a central bore 350 in which is disposed a bushing 351 having a ange 352 received in an appropriate counterbore in the top portion of the body 60. The flipper body 60 is rotatably mounted to the top of the housing 11 by way of a bolt 355 having a stem portion 356 extending through the bore 350 in the bushing 351 and a threaded'end portion 357 threaded into an appropriate threaded bore 358 in the top of the housing 11. The ipper body 60 rests on a thrust bearing plate or platform 359 and the top of the housing 11 is recessed as shown at 361 through a limited area corresponding to the extent of angular rnovements of the flipper body 60, a spacer member 360 being t? disposed in the remaining area of the recess 361 to provide an adequate support for the flipper body.

The flipper body 6i) has an intermediate extending rib 362, as best seen in FIGURES 1 and 5, and adjacent to this rib it has cutout recessed surfaces as shown in 363 and 365, which have less extent than the intermediate rib 362. The anvil holding member 62 and the secondary hopper holding member 63 are pivotably mounted to be movable about a horizontal axis by a transverse bolt 370 which extends through appropriate transverse apertures arranged in the holding members and the rib 362 of flipper body 66. The anvil holding member 62 is normally urged downwardly by a leaf spring 371. One end of the spring 371 is attached to recessed surface 363 by means such as screw 372 and the other end of this spring is attached to the anvil 335 by a bolt or screw 373 which, as best seen in FIGURE l0, extends through a bore 374 in the holding member 62 and threads into the top of the anvil 335. Formed in the holding member 62 there is a hemispherical cavity 376 in which floats the anvil 335 which is of hemispherical shape and made of a suitable material. rI`he bottom face 378 of the anvil is ilat and is lapped to a high supertinish degree of approximately 1A helium light band.

In operation the at bottom face 378 of the floating anvil seeks the atness of the die top. The mating of the anvil bottom face and the die top surface provides an absolute precise and solid tit and they are forced together in a manner as will be described presently. The cam surface 69 at the end of the holding member 62, as seen also in FIGURES l, 5, and 10, is caused to be engaged under the end part of the arm member 67 when the flipper is moved to a position that brings the anvil 335 over the die 58. This camming action forces the anvil bottom surface 37S down onto the die top surface as best illustrated in the enlarged view of FIGURE l0.

The arm holding member 63 carrying the secondary hopper is best seen in FIGURE 1 and in the enlarged view of FiGURE 9. The secondary hopper holding member 63 is also normally urged downwardly by a leaf spring 380 attached to one end by a screw 379 to the recessed surface 365 on the flipper body 6i). The other end of the leaf spring 330 is bifurcated as shown at 381 and has an upward bend as shown at 382 in FIGURE 9. The holding member 63 has a bore 335 disposed substantially vertically proximate to the er1-:l thereof, and the tube 36 which delivers the powder from the primary hopper 35 extends through this bore. The secondary hopper designated at 386 is a hollow hemisphere made of any convenient material such as, for example, tetrafluoroethylene, to the top of which the tube 36 connects as shown. In FEGURE 9, the arm or holding member 63 and the secondary hopper 386 are shown disposed directly `over the die 58 for filling the die cavities. The powder feeding down from the primary hopper into the secondary hopper 386 causes an overfill of the die cavities 314, as illustrated in FGURE 16. Before the punch end portions 312 begin the pressing stroke conipacting the powder against the anvil bottom face 378, the punches move up and expel the overfill `of powder back into the secondary hopper 336. This is an important feature of the invention since the overl'ill and expulsion of the excess powder material before compacting assures that the die cavities are always full when the pressing stroke begins.

As seen in FGURES l and 2, and in the enlarged view of FIGURE 11 illustrating the flipper position with the vacuum pickup head 65 positioned over the die 53 for picking up the nished formed articles, the vacuum pickup head 65 is mounted on the end of an arm or support 362 mounted on integral flipper body 6% and disposed between the anvil holding member 62 and the secondary hopper holding member 63. The vacuum line 76 lits an appropriate bore 46d formed in arm 362 and is connected to a bore 4201 provided with a counterbore 402. In the counterbore 1h32, there is a flexible pad 495 which can be brought down into a position over the die S to seal against it.

This pad is provided with eight circularly arranged openings 467 corresponding to the eight die cavities or bores 314 used in the present example of the invention. Above the pad 495 and openings 497 is disposed a mesh or screen member 4&9. By providing this mesh or screen member, the formed finished articles such as cores, as illustrated at 336 in FIGURE 18, are picked up by the vacuum after they have been ejected from the die cavities and held against the mesh or screen member 469, as shown in phantom lines, for transfer to the delivery distributor.

FIGURE l2 shows the vacuum pickup head in the delivery position. It will be observed that it is in this `angular position of the flipper body 6i), that the anvil holder 62 and the anvil 335 are over the rotating brush 53 which brushes any powder off the tlat bottom surface 378 of the anvil 335 that may be adhering thereto. In this position the pickup head is over a distributor plate 412 having eight circularly arranged openings 13 corresponding to the pattern of openings in the die. The mesh or screen member 499 and pad it' are over the pattern of openings 413. At this time the vacuum is momentarily broken or cut oif so that the vacuum head releases the formed 1inished articles or cores 336 which drop down through the openings 413 into the group of tubes which connect to these openings and deliver the formed finished articles to a corresponding number of vials or bottles as previously described. In this position the secondary hopper 386 is over the die cavities filling them with powder. Consequently, the die cavities are filled, the nished articles dropped into the discharge tubes, and the anvil brushed olf, all in the same position of the flipper 56.

Briefly summarizing the movements of the ipper assembly, it will be observed that in the position in which it is shown in FIGURE l, the vacuum pickup is over the die cavities. in the position of FIGURE l2, the finished articles are expelled, the anvil is brushed and the cavities are filled. After the overiill of powder has been expelled, the flipper is moved to the position shown in FIGURE 11 in which the cores or lnished formed articles are ejected from the die cavities and picked up by the vacuum. The flipper then moves to transfer the picked up cores or articles to a position as shown in FIGURE l2 wherein they are discharged or delivered to the vials or bottles, the anvil is in the position to be brushed oif by the brush 53 and the die cavities are iilled.

ADIUSTMENTS BEF ORE OPERATION As has been previously mentioned, among the important features of the invention is the capability of precision adjustments of the fill position of the punches and the extent of the pressing stroke whereby the powder is compacted as well as the extent of the ejecting stroke of the punches. In making ferrite cores, by Way of example, the dimensions of the finished articles have to be held to an accuracy within 1/10 of a thousandth of an inch in thickness resulting in machine operation adjustments capable of precise control to within at least fifty millionths of an inch.

A preferred manner of making adjustments is as follows:

The shaft 15 is rotated by way of the hand wheel 32 so that the high point of fill cam 122 is against or tangent to the core 92. This actuates the lever mechanism 93 to position the stem and the tool holder for the punches to a predetermined position. The punches can then be adjusted to the desired position, measured in thousandths of an inch or tenths of a thousandth of an inch, by adjusting the till cam 122 along the threaded shaft 15 in the manner described above. By way of example, when the cone 92 has a one degree angle of slope, with a forty micrometer pitch thread on the shaft 15, one degree of rotation of the nuts 172 and 173 adjust the position of the ll cam 122 to produce a one millionth of an inch adjustment in the position of the punches through the lever mechanism 93. Similar adjustments may be made in the eject position of the punches by adjusting the eject cam 123. The adjustment of the eject cam may be made before the adjustment of the till cam, if desired. The correct adjustment of the iill cam 122 for filling the die cavities automatically takes care of the correct position or movement of the punches for the overiill. Similarly the press cam 121 is adjusted to produce the exact correct thickness of the core desired after being pressed or compressed.

By reason of these adjustments as aforesaid, the diverse positions of punch end portions 312 and core rod end portions 326 can be determined with great precision so that there is always the correct, accurate amount of fill and that the cores are compacted or compressed to the exact, correct thickness. It will be observed that not only are the adjustments extremely precise, but they are very positive and dependable and maintain their accuracy during long periods of operation.

SUMMARY OF OPERATION The adjustments described above are, of course, made before operating the machine of the invention. In operation the machine is driven by the motor 30 rotating at an appropriate substantially constant speed so as to continuously repeat the operating cycle for compacting and producing the compacted articles eight at a time, in the present example of the invention including eight cavities in the die.

For convenience, the description of the operation of the machine has been arbitrarily chosen to begin with that point in the cycle when a group of compacted finished articles have just been ejected from the die by operation of the eject cam. The eject cam 123 has a single lobe as indicated in FIGURE 15. When this lobe engages the cone 92 and operates the lever actuating mechanism 93 the stem S5 and the punch end portions 312 are moved upwardly to eject the finished articles, that is, they are moved to the position as shown in FIGURES 11 and 18 in which the finished articles are ejected. At this time, the iiipper is angularly :positioned to a position placing the vacuum pickup head 65 over the die 58, as shown in FIGURE 18, and the source of vacuum is connected to the bore 401 in the head for lifting the finished articles against the mesh or screen member 409. The next motion in the cycle is initiated by the flipper cam 101 angularly positioning the iiipper to cause the pickup head 65 to occupy the position of FIGURE 12, with the pickup head over the discharge distributor 412. The flipper, in this position, actuates a valve of any suitable type, not shown, to momentarily cut-off the vacuum so as to release the formed finished articles to allow them to drop into the tubes 80. At this time the secondary hopper 386 is over the die in the position of FIGURE 9, and powder is allowed to flow from the primary hopper 35 into the secondary hopper so as to fill the die cavities 314. Next in the cycle, the fill cam 122 actuates the cone 92 and the lever mechanism 93 to move the punch end portions 312 into the overiill position wherein the die cavities are overlilled and the punches are displaced to a position expelling the excess powder from the die cavities back into the secondary hopper. If toroidal cores are being formed, the core rod cam 97 operates in the manner described in the foregoing to displace the core rod end portions 326 to a position wherein their ends are ush with the top surface of the die, that is as shown in FIGURE 10. Next in the cycle, the flipper cam 101 operates the lever 280 to move the iiipper so as to position the anvil 335 over the die while moving the secondary hopper 386 away from the die. In the course of this motion, the lower edges of the secondary hopper act as wipers wiping off any loose powder from the top surface of the die. Next in the cycle, the press cam 121 comes into action and actuates the lever mechanism 93 to move the punches toward the anvil bottom surface 378 for compacting the powder lling the die cavities into the toroidal cores,

12 as illustrated in FIGURES l0 and 17. The cores having now been formed, the iiipper cam 101 now again acts to angularly shift the iiipper to move the anvil away from a position over the die, while at the same time positioning the pickup head 65 over the die, as illustrated in FIGURES ll and 18. The eject cam 123 now operates lever mechanism 93 to further displace upwardly the punch end portions 312 to eject the formed iinished articles.

From the foregoing description of an example of a machine and method according to the invention, those skilled in the art will observe that the invention herein achieves and realizes all of the objects and advantages as stated in the introduction, as well as having manifold additional advantages that are readily apparent from the detailed description.

The foregoing disclosure is representative of a preferred form of the invention and is to be interpreted in an illustrative rather than a limiting sense, various modifications being contemplated as may obviously be resorted to by those skilled in the art without departing from the spirit and scope of the invention, as hereinafter defined in the appended claims,

What is claimed is: 1. A method for making simultaneously a plurality of articles of predetermined dimensions and density compacted from powder by means of a die having a plurality of cavities and a plurality of reciprocable punches, each of said punches being disposed at the bottom of each of said cavities, said method comprising:

disposing a hopper over said die, said hopper having a lower edge engaging the surface of said die;

lling said hopper with the powder to a predetermined level so as to completely iill said cavities;

reciprocating the punches simultaneously to a iirst predetermined position causing an overiiow of the excess powder from each of said cavities back into said hopper and a predetermined amount of powder to remain in each of said cavities;

removing said hopper from over said die and simultaneously removing the excess of powder not contained in each of said cavities as a result of the wiping action of the edge of said hopper on the surface of said die;

placing an anvil surface over said die for closing said cavities; reciprocating the punches simultaneously to a second predetermined position toward said anvil surface for causing a predetermined compaction of said predetermined amount of powder in each of said cavities so as to form a plurality of said compacted articles;

removing said anvil surface from over said die; and

reciprocating said ypunches simultaneously to a third predetermined position for ejecting said compacted articles from said cavities;

whereby said punches are snugly fitted within said die cavities and are held longitudinally rigid for reciprocation within each cavity by a circularly arranged holder permitting each of said punches to be radially displaceable relative to said holder enabling accurate guiding of said punches within said cavities during reciprocating movement of said punches.

2. The method of claim 1 further comprising:

placing an ejector member Vover said cavities in said die, said ejector member having a first closure provided with an upper porous wall separating said iirst closure from a second closure;

simultaneously sucking said articles by connecting said second closure to a source of uid at a pressure lower than atmospheric pressure for causing said articles to be ejected into said iirst closure and to remain adhering to said upper porous wall;

displacing said ejector member over a plurality of outlets; and

disconnecting said second closure of said ejector member from said source of iiuid for causing said articles to drop each into one of said outlets.

3. The method of claim 2 further comprising: brushing said anvil surface by means of a rotating brush for removing from said surface any powder remaining attached thereto previously to placing said anvil surface over said die.

4. A method for making simultaneously a plurality of toroidal articles of predetermined dimensions and density compacted from powder by means of a die having a plurality of cavities and a plurality of reciprocable punches, each of said punches being disposed at the bottom of each of said cavities and each of said punches having a core rod disposed concentrically within a longitudinal bore therewithin and reciprocable independently therefrom, said method comprising:

disposing a hopper over said die, said hopper having a lower edge engaging the surface of said die; filling said hopper with the powder to a predetermined level so as to completely till said cavities;

disposing each of said core rods to a position whereby the end thereof is substantially flush with the top of each of said cavities;

reciprocating the punches simultaneously to a first predetermined position causing an overflow of the excess powder from each of said cavities back into said hopper and a predetermined amount of powder to remain in each of said cavities;

removing said hopper from over said die and simultaneously removing the excess of powder not contained in each of said cavities as the result of the wiping action of the edge of said hopper;

placing an anvil surface over said die so as to close said cavities;

reciprocating the punches simultaneously to a second predetermined position toward said anvil surface for causing a predetermined compaction of said predetermined amount of powder in each of said cavities so as to form a plurality of said compacted toroidal articles;

removing said anvil surface from over said cavities; and

reciprocating said punches simultaneously to a third predetermined position for ejecting said toroidal compacted articles from said cavities;

whereby said punches are snugly fitted within said die cavities and are held longitudinally rigid for reciprocating Within said cavities by a circularly arranged holder permitting each of said punches to be radially displaceable relative to said holder enabling accurate guiding of said punches within said cavities during reciprocating movement of said punches, and

whereby said core rods are snugly fitted within said longitudinal bores of said punches and are held longitudinally rigid for reciprocation within said bores by a circularly arranged holder permitting each of said core cord to be radially displaceable relative to said holder enabling accurate guiding of said core rods within said bores during reciprocating movement of said punches.

5. The method of claim 4 further comprising:

placing an ejector member over said cavities in said die, said ejector member having a first closure provided with an upper porous wall separating said first closure from a second closure;

simultaneously sucking said toroidal articles by connecting said second closure to a source of fluid at a pressure lower than atmospheric pressure for causing said toroidal articles to be ejected into said first closure and to remain adhering to said upper porous wall;

displacing said ejector member over a plurality of outlets; and

disconnecting said second closure of said ejector memher from said source of fiuid for causing said toroidal articles to drop each into one of said outlets.

6. The method of claim 5 further comprising: brushing said anvil surface by means of a rotating brush for removing frorn said surface any powder remaining attached thereto previously to placing said anvil surface over said die.

References Cited UNITED STATES PATENTS 1,007,831 lll/1911 Whitney 25-103 2,127,994 8/1938 Davis et al 264-l09 3,142,863 8/1964 Mazzoni 25-1 ROBERT F. WHITE, Primary Examiner.

I. R. HALL, Assistant Examiner.

Claims

1. A METHOD FOR MAKING SIMULTANEOUSLY A PLURALITY OF ARTICLES OF PREDETERMINED DIMENSIONS AND DENSITY COMPACTED FROM POWDER BY MEANS OF DIE HAVING A PLURALITY OF CAVITIES AND A PLURALITY OF RECIPROCABLE PUNCHES, EACH OF SAID PUNCHES BEING DISPOSED AT THE BOTTOM OF EACH OF SAID CAVITIES, SAID METHOF COMPRISING: DISPOSING A HOPPER OVER SAID DIE, SAID HOPPER HAVING A LOWER EDGE ENGAGING THE SURFACE OF SAID DIE; FILLING SAID HOPPER WITH THE POWDER TO A PREDETERMINED LEVEL SO AS TO COMPLETELY FILL SAID CAVITIES; RECIPROCATING THE PUNCHES SIMULTANEOUSLY TO A FIRST PREDETERMINED POSITION CAUSING AN OVER FLOW OF THE EXCESS POWDER FROM EACH OF SAID CAVITIES BACK INTO SAID HOPPER AND A PREDETERMINED AMOUNT OF POWDER TO REMAIN INEACH OF SAID CAVITIES; REMOVING SAID HOPPER FROM OVER SAID DIE AND SIMULTANEOUSLY REMOVING THE EXCESS OF POWDER NOT CONTAINED IN EACH OF SAID CAVITIES AS A RESULT OF THE WIPING ACTION OF THE EDGE OF SAID HOPPER ON THE SURFACE OF SAID DIE;