US 3822974 A
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Description (OCR text may contain errors)
United States Patent 1 91 DeSantis et al,
1111 3,822,974 451 July 9,1974
 TOOL SET FOR POWDER COMPACTING 2,798,255 7/ 1957 Winters 425/78 PRESS 2,883,703 4/1959 Frank 425/78 1 3,574,892 4/1971 Smith 425/78 Inventors: y o d S s, y O 3,671,157 6/1972 Smith 425/78 Georges D. DeTroyer, Grosse Ile, both of Mlch' Primary ExaminerRobert L. Spicer, Jr.  Assignee: Wolverine-Pentronic, Inc., Lincoln Attorney, g or F i m, Gifford, Palalidis Park, Mich. & Dumont  Filed: Aug. 23, 1972 21 Appl. No.: 282,965  ABSIRACT I A tool set for use in conjunction with a die plate having at least one die cavity in it and at least one lower 2% F' 'S 5 65 545; punch mounted for movement into the die cavity to I I q 425/78 256 352 compact a powder material and produce a finished ar-  d 0 re ticle. The tool set includes both punch and core rod, with the punch movable into the die cavity during the v press operation. The core rod is fixed with reference  References cued to the die cavity and extends into the cavity to provide UNITED STATES PATENTS an aperture in the finished article. The core rod and 2,122,874 7/1938 Whipple 425/78 its special resilient type mounting facilitate sliding 2,253,003 1941 pp 8 15 37 movement of the punch relative to the core rod. 2,767,438 10/1956 Pingel 5 I 7 2,791,804 5/1957 Talmage 425/78 X 5 Claims, 4 Drawing Figures a /e l/ 4 3X /0 l/ I I za 3'8 I I Z 4 I 5 I I 4 I /l@ I X I g I :1 0 o I p: t
| I l I@ l as I@ a l I I Z v k l I I I "'1 I I i i i I PATENTED JUL SISH sum 2 or 2 BACKGROUND OF THE INVENTION l.- Field of the Invention The present invention relates to a powder compacting apparatus, more particularly one of the multiple die cavity type, and to an improved tool set for providing finished articles from a powder material which articles have an aperture formed in them during the press operation.
2. Description of the Prior Art The present invention represents an improvement over prior art tool sets for compacting presses. The tool set is suitable for use with work station positioners and compacting presses of the type disclosed in US. Pat. No. 3,574,892 issued Apr. 13, 1971 to Joseph E. Smith for Powder Compacting Press, which patent is of common ownership with the present application. The apparatus disclosed in the aforementioned patent is a press and associated tooling for'the purpose of manufacturing compacted articles such as toroids, beads, pellets and the like made of powdered ferrite, glass or other like powder substances capable of forming a compacted article upon the application of a pressure in a confined die cavity. T
In the powder compacting press disclosed in the aforementioned patent, the articles are compacted and formed in a multiple cavity die forming part of a punch and die set, withthe finished articles being automatically ejected from the die cavities, removed by a pickup head, and dropped through discharge ports into suitable receptacles. The work station positioner assembly, which is included as a part of the press, is mounted above and movable transversely over the upper surface of the die plate. The positioner assembly carries a powder dispenser, an anvil and a pickup head. The powder dispenser is supplied with powder from a primary powder supply means connected to it by a flexible tubing. The powder dispenser is first positioned over the die cavities, which are thus filled with powder as the punches are first displaced downwardly in order to draw a predetermined amount of powder into the die cavities. The dispenser is then removed from above the cavities by the subsequent angular motion of the positione'r assembly, and the anvil is next positioned over the die cavities. The anvil is clamped over the die cavities by means of a pivotable clamp supported above it and actuated in timed relationship with the press movement of the punches. The anvil is thus held down with sufficient pressure to permit the compacting of the powder against it as the result of an upward motion of the punches into the die cavities. The anvil is then removed from its position over the die cavities and is replaced by the pickup head as the result of a further angular movement of the positioner assembly transversely across the upper face of the die plate. The punches are displaced upwardly in order to bring their ends in substantially flush alignment with the upper surface of the die plate so that the finished compacted articles are ejected from the upper ends of the die cavities and then picked up by thepickup head. As the result of a return angular motion of the work station positioner assembly to the initial fill position, the pickup head is'removed from over the die cavities and is disposed over a series of discharge apertures in like arrangement to the die cavities to drop the compacted articles into containers.
The punch and die assembly disclosed and explained in the aforementioned patent is particularly useful for forming toroidal-type articles, and the improved tool set constructed in accordance with the present invention is specially adapted for'that purpose.
SUMMARY OF THE INVENTION In accordance with the present invention, an improved tool set is provided with a particular mounting arrangement for each core rod and its associated punch which permits the best possible alignment of the core rod with the internal bore of the punch to prevent binding, gouging or breakoff of the core rod within the punch bore during the punch movement for press operation. Additionally, the construction of the tool set, and particularly the parts for mounting the core rods, are such that adhesive binding or press-fit is not needed to fasten the core rods securely in place. This permits the ready removal and replacement of the core rods in the tool set when repair is required.
The several objects and advantages of the present invention will become apparent to those skilled in the compacting press art from the drawings when taken in conjunction with the following description.
BRIEF DESCRIPTION OF THE DRAWINGS The. description herein makes reference to the accompanying drawings wherein like reference numerals are used to refer to like parts where they may occur throughout the several views, and in which:
FIG. 1 is a top plan view of a multiple cavity die plate and punch assembly tool set as they would be mounted for operation in a powder compacting press;
FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, to illustrate the several different parts of the tool set and their relationship to each other and to the upper die plate;
FIG. 2A is a partial view to enlarged scale of a portion of the FIG. 2 drawing; and
FIG. 3 is an inverted exploded perspective view to show the separate parts which would be assembled to form a complete tool set.
DESCRIPTION or THE PREFERRED .EMBODIMENT Referring now to the drawings and with particular reference to FIGS. 1 and 2, there is shown a die plate 10 adapted to be seated in a press table 11 as part of a powder compacting press of the general type disclosed in the aforementioned U.S. Pat. No. 3,574,892. The die plate 10 has a flat upper surface 12 and is held securely to the press table 11 by a suitable means, such as die clamp plates 14 and 16. The plate 16 preferably includes a three-point clamping arrangement as shown in the drawing for secure locking engagement. A pair of screws 18 and 20 are included which extend through predrilled holes in the clamp plates 14 and 16, respectively, and into the press table 11. In the embodiment illustrated there are shown 14 die cavities, although the number may vary according to the production requirement and the size of the parts. The several die cavities are indicated by the numeral 22. Each die cavity 22 is formed by a die bushing 24, with the upper end surface of the die bushing aligned flush with the upper surface 12 of the die plate 10. Each die bushing 24 further has a centrally located bore 26 which is shown as being of circular cross section, although it will be obvious that the bore may as well be rectangular, square or of any appropriate cross-sectional shape according to the desired peripheral shape of the article to be compacted. The bore 26 extends downwardly from the upper surface 12 of the die plate throughout its width.
The die plate 10 is further provided with a pair of oppositely disposed vertical bores 28 and 30. Fastened in each of the bores 28, 30 are guide posts 32 and 34, respectively. The guide posts 32, 34 are of an elongated cylindrical shape and are preferably retained within the respective bores 28, 30 by a suitable adhesive or bonding compound. One example of a bonding compound which may be used is known and sold under the name Loctite," currently manufactured by the Loctite Corporation, Newington, Conn. This compound is particularly useful in bonding cylindrical-shaped parts, has excellent heat and solvent characteristics and provides a high sheer strength between adjacent interfaces. Also indicated in FIG. 1 are threaded fasteners 36 and 38 which are used to attach certain adjacent punch retaining parts of the tool set to each other, as will be better shown in FIG. 3 hereinafter. A screw 80 is shown which is used to fasten a retainer plate 66 (FIG. 2) to one of the guide posts 32.
FIG. 2 shows the tool set 40 as it is mounted below the die plate 10 during operation of the press. One of the two guide posts, post 34, is shown for holding the tool set 40 in place relative to the die plate 10. FIG. 2 also clarifies the manner in which the die clamp plates 14 and 16 are used to hold the die plate 10 securely in place on the press table 11. The die clamp plate 14 has a rightwardly extending upper marginal portion 140 which overlaps a mating lateral extension 10a at the left handedge of the die plate 10. In a like manner, the die clamp plate 16 has a left hand extending upper marginal portion 16a which overlaps a mating lateral exten sion 10b of thedie plate 10. Included in the tool set 40 are a plurality of punches 42, one of which is shown. Each punch 42 includes a lower cylindrical or head portion 420 and an upper reduced or rod portion 42b, which during press operation is driven upwardly into the die cavity 22. Each of the punches 42 is retained in one of a series of cut-out portions 43 formed about the periphery of a punch support plate 50. The punch support plate 50 further includes a pair of spaced bores 51, one of which is shown, containing a guide bushing 52. Each guide bushing 52 is further slidably mounted on one of the guide posts 32, 34. Each guide bushing 52 additionally passes through a complementary bore 57 formed in a stem plate 54. In its assembled position, the stem plate 54 is held flush against the opposed surface of the punch support plate 50. A resilient pad or resilient coating may be inserted between the lower punch portion 42a and the stem plate 54 to compensate for machining tolerances on the punch 42. Additionally, a resilient pad or coating 45 may also be inserted between the punch portion 42a and the punch support plate as shown in FIG. 2A. It will be understood that such resilient pads or coatings may alternately be mounted on the respective plates 54 or 50. Each punch 42 may be further held in place in punch support plate 50 by a suitable adhesive applied between its head 42a and the cut-out portion 43 which holds it. Each ofthe punches 42 has an internal bore 420 adapted to receive a core rod 56 in such manner that the punch 42 is slidably movable on the core rod 56. Each core rod 56 further includes an upper reduced or rod portion 56b and an enlarged head portion 56a. Each core rod 56 is held in place through its engagement in a marginal cut-out .portion 55 in a core rod support plate 62. A resilient pad 64 is mounted between each core rod head portion 56a and the opposed surface of a lower retaining plate 66. The resilient pad 64 is of particular importance with respect to the operation and performance of the tool set.
During assembly of the tool set, which process will be clarified hereinafter in FIG. 3, it is important that each core rod 56 be properly aligned with the mating bore in the associated punch 42. Otherwise, during operation, the core rod reduced portion 56b will tend to bind in the mating punch bore 420 and may cause breakoff of the core rod 56 or excessive wear to the internal bores 42c. Insertion of a resilient means, such as the pad 64, in the location indicated at FIG. 3, makes it possible for the core rod 56 to deflect slightly during the sliding movement of the associated bore 420 of the punch 42 along it. It will be understood that, while the coating or pad are nylon, teflon or the like. Another distinct and important advantage arising from the resilient pad mounting system is that the core rods are firmly anchored but still readily replaceable in the tool set 40, which represents a distinct improvement over prior art systems in which the core rods are retained by adhesive binders or press-fit in their position.
Also shown in the FIG. 2 drawing is a threaded fastener which is used to provide fastening of the retaining plate 66 to the core rod support plate 62. It will further be seen that the stem plate 54 terminates in a lower shaft 72, the lower end 74 of which is adapted to receive the upward drive from the punch operating mechanism, not shown, which moves the movable parts of the tool set 40 in an appropriate direction to accomplish the several different sequences of operation, namely fill, press and eject.
With reference to FIG. 3, it will be understood that the parts of the tool set 40 are shown in a position inverted from that in which the final assembled tool set would be used in the press. The tool set 40 parts are thus illustrated in a position which clarifies the general order in which they would be assembled on a work bench before being mounted in the press. The assembly process briefly described is as follows: The parts are first cleaned and demagnetized prior to assembly. The die plate 10 is laid on the bench and each die bushing 24 has applied to its outer surface a bonding material, such as Loctite.'Each bushing 24 is then pressed into the die cavity 22 provided in the die plate 10. The guide posts 32 and 34 are inserted into the respective vertical bores 28 and 30 formed in the die plate 10 with a similar bonding material applied for holding them firmly in place. Each punch 42 is mounted into the cut-out portion 43 provided for it in the punch support plate 50. It will be seen that the stem plate 54 and the punch support plate 50 are attachedfirmly together through the pair of screws 36, 38. In this manner, each of the punches 42 is held in position in the tool set. The resilient pads 45 may also be included as shown in FIG. 2A.
Each of the core rods 56 is likewise mounted in the cutout portions 55 provided in the core rod support plate 62 and in each case the resilient pad 64 is inserted be tween the head portion 56a of the core rod 56 and the opposed surface of the core rod retaining plate 66. The fastener screw 70 is used to securely attach the retainer plate 66 to the core rod support plate 62. A screw 80 is used to securely fasten the retainer plate 66 to the guide post 32 and a similar attaching arrangement may be included for the guide post 34. The general arrangement of the tool set is such that in the final assembled condition the guide posts 32, 34 are bonded and securely fastened to the die plate 10. The punches 42 are firmly seated in the upper punch support plate 50 in such manner that they are automatically aligned with openings in the die bushings 24.
The punch support plate 50 has press fitted or bonded to it the guide bushings 52, which bushings in turn are slidably fitted on the guide posts 32, 34. The core rods 56 in accordance with the improved construction shown are held together securely by the core rod support plate 62 and retainer plate 66 in such manner that they need not be bonded in place. This permits the individual core rods 56 to be replaced with only a partial disassembly of the tool set 40. The end portion 74 of the tool stem 72 passes through the central bore 73 provided in the retainer plate 66 and is adapted to be engaged by the press ram, not shown, to provide the actual movement of the tool set parts through the several motions and positions required for the fill, press and eject operations. It will be seen that the punches 42 and the several associated parts which retain them in place form the only moving parts of the tool set and their motion is properly synchronized with the oscillation of the positioner already described to provide the fill, press and eject operations.
It will thus be seen that the present invention provides a new and improved tool set for forming apertured compacted parts which is particularly adapted to provide multiple cavity operation for a compacting press. The improved mounting arrangement for the core rods facilitates their initial assembly and the repair of the tool set, as well as substantially'improving its durability in operation.
What is claimed is:
lQA tool set for use in conjunction with a press, said tool set comprising a die plate having at least one die cavity, a pair of spaced guide posts fixed to said die plate and normal to one surface thereof, a punch support slidably mounted on said posts and cyclically movable toward and away from said die cavity by a ram of said press, at least one punch mounted on said punch support, said punch having its longitudinal axis aligned with the longitudinal axis of said die cavity and alike peripheral sizing to said die cavity, said punch further having a longitudinal bore therethrough, a core rod having an enlarged mounting head portion and a reduced end portion slidably projecting through said punch bore and having a length sufficient to extend through the entire length of said die cavity, a core rod support means fixed to said guide posts, said core rod support means consisting of a pair of spaced apart substantially parallel support plates and one of said plates having an aperture for passage therethrough of the reduced end portion of said core rod with the enlarged mounting head portion of said core rod disposed between said mounting plates, a pad of resilient material disposed between the end of the mounting head portion of said core rod and the other of said mounting plates for permitting a limited deflection of said core rod during sliding movement of said core rod through said' punch bore during assembly and operation of the tool set and clamping means for drawing said mounting plates toward each other for holding therebetween the enlarged mounting head portion of said core rod.
2. The tool set of claim 1 wherein said pad of resilient material is a separate resilient pad of substantially the same diameter as said enlarged head portion of said core rod.
3. The tool set of claim 1 wherein said pad of resilient material is a coating of resilient material applied to the surface of said other of said mounting plates.
4. The tool set of claim 1 wherein said punch support comprises a pair of spaced apart substantially parallel support plates, one of said plates having an aperture for passage therethrough of the reduced end portion of said core rod and the other of said plates having an aperture for passage therethrough of said punch, said punch having an enlarged mounting head portion disposed between said mounting plates, a pad of resilient material disposed between the end of said punch enlarged head portion and the first of said plates, and clamping means for drawing said plates toward each other for holding therebetween the enlarged mounting head portion of said punch.
5. The tool set of claim 4 wherein a plurality of die cavities are included in said die plate and a like plurality of punches and core rods are included in said tool I set, said die cavities, punches and core rods being disposed in a predetermined array.