US2556951A - Powdered material compacting press - Google Patents

Description

3 Sheets-Sheet l J'. E. WEIDNER POWDERED MATERIAL COMPACTING PRESS INVENTOR.

3 0 I flw June 12, 1951 Filed June 5, 1944 I J0 w 3/ w W M June 12, 1951 J. E. WEIDNER POWDERED MATERIAL COMPACTING PRESS "3 Sheets-Sheet 2 Filed June 5, 1944 Patented June 12, 1951 POWDERED MATERIAL COMPACTING PRESS Jack E. Weidner, Milwaukee, Wis., assignor, by mesne assignments, to F. J. Stokes Machine Company, Philadelphia, Pa., a corporation of Pennsylvania Application June 5, 1944, Serial No. 538,865

42 Claims. :1

This invention relates to improvements in presses, and particularly to a hydraulically operated press for molding powdered materials.

It is well known that certain types of powdered materials, such as dry ceramic materials, powdered metals, and the like, have very poor flow characteristics and will compact in the position placed in a die cavity rather than fiow to different levels therein. Due to the compacting and non-flowing action of the material, the die cavity must be uniformly filled with the powdered material before pressing. Such materials require a molding die with independent punches for the various thicknesses of the finished piece, with separate movements into the filling position and in the pressingposition for each thickness so that the resulting piece will be of uniform density in its various sections. Furthermore, prior to firing or sintering, compacted pieces are fragile and must be ejected from the die in such manner as to avoid breakage or even the setting up of stresses in the piece which result in cracks when the piece is fired.

Presses for molding powdered materials are known as tableting or pelleting presses andare characterized by a stationary-die ring having the shape of the periphery of the finished piece'and by upper and lower punches entering the die ring to press the upper and lower surfaces of the pieces. Mechanically operated presses having the a steps of the operation of molding powdered materials and result in defective and non-uniform pieces.

It is an object of the present invention to provide a press for compacting powdered material into fiat or unflanged pieces, pieces having the general outline of a cone and pieces having the general configuration of a cup, simply by interchanging of die parts or change in their movements.

Another object of the invention is to provide a press for compacting powdered material into pieces of different shapes in which the dies used 1 "2 are simple blocks, rods, and tubes or sleeves, without stops and without any movable pieces on the die parts themselves.

Another object of the invention is to provide a press for compacting powdered material into various shapes, ,in which all of the die elements may be individually controlled during all or a portion of each of the several steps of filling the die cavity, pressing the material, and ejecting the molded piece.

Another object of the invention is to provide a press for compacting powdered material into articles of a high degree of uniformity in density, size,.and other characteristics.

Another object of the invention is to provide a press which powdered material to be compacted is filled into a die cavity under the pressure of a constant column of the material and is uniformly distributed throughout the entire die cavity,'thus maintaining accuracy in the amount of material used for any production run of a given pressed piece.

Another object of the invention is to provide a press for molding powdered materials in which movement of the die parts is so controlled as to present an invariable die cavity during the entire productionrun of a given piece.

Another object of the invention is to provide a press for compacting powdered materials in which the pressure exerted during the entire production of any given piece is maintained at its predetermined value, thus maintaining accuracy of size and uniformity of density of any number of the given piece produced at one setting of the press parts.

Another object of the invention is to provide a press for molding powdered materials in which the pressure is uniformly exerted throughout the entire mass of the article being molded regardless of the volume of any given section of the article.

Another object of the invention is to provide a press for compacting powdered materials in which the compacting pressure is exerted by way of one of the die parts'against the yielding resistance of another die part and final pressure is exerted by the one .die part against a fixed stop.

Another object of the invention is to provide a molding press in which such differential movements of the ejecting die parts are avoided, particularly during ejection of the compacted piece from the die, as might cause breakage or deformity of the piece.

Another object of the invention is to provide an improved compacting press for powdered materials which is capable of a high rate of output, is

3 economical in operation and maintenance, and is durable in construction while readily adjustable to the making of pieces of different sizes, configuration, and density.

Objects and advantages other than those above set forth will be apparent from the following description when read in connection with the accompanying drawings, in which:

Fig. 1 is a view partially in front elevation and partially in section of a press embodying the present invention with the parts in compacting or pressing position but omitting the punches for compacting the material;

Fig. 2 is a partial View in side elevation of the press;

Fig. 3 is a vertical sectional enlargement of portions of the several die holders and of a particular set of dies for a cup-shaped piece shown in the position assumed when the press has reached the end of its material-compacting stroke;

Fig. 4 is an enlarged vertical sectional view of the die holder for the outer lower die punch and its associated stop plate;

Fig. 5 is an enlarged view partially in elevation and partially in vertical section of the die holder for the inner lower die punch;

I Fig. 6 is a vertical sectional view on a plane perpendicular to Fig. 1 of the die core rod and the parts for holding the die core rod;

Fig. 7 is an enlarged partial side elevation of the mechanism for filling the die cavity with powdered material;

Fig. 8 is a sectional view taken on a vertical central plane through a portion of the filling mechanism shown in Fig. 7;

Fig. 9 is a cross sectional view taken on the plane IXIX of Fig- 8;

Fig. 10 is a diagrammatic view in vertical cross section showing the relationship of the principal elements of the press; and

Fig. 11 is a view similar to Fig. 3 but showing punches for molding a piece of conical configuration.

Referring more particularly to the drawings by characters of reference, a base structure is formed of structural steel shapes such as beams ll, of any desired section, connected by crossbeams or plates !2, preferably in a rectangular shape, to form a structure of suflicient rigidity and size to support the weight of the press over an area sufficiently large to minimize the amount of foundation required under the press.

A frame structure, including side plates i5 and a front plate I6, is mounted on the base I I, i2 to form both a partial enclosure and a support for a block IS in which are mounted a plurali ty of motor means shown as hydraulic pressure cylinders 2D, 2!, and 22 having connections indicated at 23, 24 and 25, 26, and 21, 28 with a source of suitable fluid pressure (not shown). The cylinders 26, 2! and 22 are fluid pressure motors which are well known as comprising cylinders with pistons having exteriorly extending rods and are not further described. The block i9 is substantially recontagular and has threaded bosses in the corners thereof in which are mounted circular bars 30 extending upwardly from the block l9 and defining a main press frame. The corner bars or posts 30 have mounted thereon a centrally apertured pressure plate 3! which is held against downward movement only, and forms a fixed stop limiting movement of some of the press parts, by collars 32 on the corner posts beneath the plate, the collars 32 4 resting on shoulders on the posts 30 or being otherwise held in place by suitable fastening means by which the lowermost position of the plate 3i may be fixed.

A centrally apertured plate 35 is mounted on the corner or frame posts 38 above the pressure or stop plate 3| and is held in fixed position on the posts 30 by locking collars 36 and 31 fixed on the posts both below and above the plate 35. The plate 35 is held against movement in either direction and provides a stationary mounting on which a stationary die part (such as the core rod) may be mounted.

A plate 40 is mounted above the bracket or mounting plate 35 and interconnects the upper ends of push rods 4i and 42 which are connected with and extend upwardly from the pistons of the cylinders 29, 22. Movement of the plate 40 is guided by the frame corner posts 30 and is limited in the downward direction by contact through sleeves with the pressure or stop plate 3|. The plate 40 is formed with a rabbeted or stepped opening 43 therethrough to form a holder for one of the movable die parts which is, generally speaking, formed as a sleeve. A ring 44 of larger diameter than that of the opening 43 is mounted about such opening on the underside of the plate 40 and is secured to the plate by screws 45 extending through the plate into the ring. The ring 44 is externally threaded to receive a sleeve 46 which is adjustably locked to the ring, as indicated at 41 and 48. The lock part 47 is preferably a key engaging in a keyway in the ring 44 and locking grooves in the sleeve 46 and extending over the top of the sleeve 46 and locked against movement therefrom by the screw 48. The sleeve 46 may engage with a sleeve or ring 49 which is mounted at its lower end on the pressure plate 3| by screws 59 to form means for transmitting pressure on the plate 4i? to the plate 3|.

A table 5| is mounted in fixed position on the corner posts 38 by locking collars 52 and 53- The table 5| has an opening therethrough formed (see Fig. 3) with a plurality of rabbets from the upper edge to receive a die ring 56 forming a mold into which the other die parts enter in compacting the piece, the die ring 56 being held in place .by a retaining ring 51 secured to the table by screws 58. A ring BI is mounted on the underside of the table about the opening therethrough and is held to the table by screws 62. The ring BI is externally threaded for the positioning thereon of a ring 63 which forms an adjustable stop for limiting upward movement of the punch holder 41? and its punch when the compacted piece is being ejected, as will be described. The rings 6i and 63 are locked together by a locking means including a key 64 and a screw 65 for setting the position of the key. The table extends beyond the space defined by the corner posts and serves as a mounting for a die filling mechanism to :be described.

A plate 58 is mounted on the frame posts 36 for movements to bring an upper punch into and out of the die ring 56 in the table 5i Movement of the plate (it is guided by the posts 36 and is produced by motor means in the form of a fluid pressure cylinder t? similar to the cylinders 26, 2| and 22 and shown only in elevation. The pressure cylinder 51 is mounted in a head plate '68 to which the upper ends of the corner posts so are connected and which completes the frame or supporting structure for the press. The cylinder 6'! of course is provided with a piston having threaded at the end thereof iorengagement with a sleeve 18 fitting into a socket in the plate .66 and preferably pinned therein against rotation, as indica-tedat l I. The piston rod andthe sleeve are held in thesocket in the .plateby a retaining and locking ring 12 threaded .on the piston rod 69 and locked to the plate 66 by screws 13.. A split rin PM is threaded on the piston rod between the plates 65 and 68 to act .as an adjustable stop in conjunction with the end of .the cylinder for limiting the extent to which the plate fill may :be moved above the table The plate I56 hasrods 1.6 secured theretoand depending irom the plate to pass through .holes in the table 5!, the punch with an upper punch holder ll secured to the under side of the plate, as by screws 18., .and provided with a socket for receiving the stem of an upper punch generally designated 9..

A frame 8! is mountedon the base II, I2 toone side of the press structure described above and forms supporting and enclosing means for pumps and their drive, .for pipes ..connecting;such pumps with cylinders 2? 2i, 22,;and 61, and for control valves by which distribution :of pressure tosuch cylinders is controlled, :all of which are a separate invention :and not disclosed herein. The frame @I also has mounted thereon a hydraulic pressure cylinhr operated filling mechanism generally designated 32 by which powdered materials .are conveyed in measured .quantity.from ahopper as to the cavityin the table which its-defined the various die parts.

The pushrods 4:! and '42, connected with the piston ,rods :of the lower :hydraulic cylinders 2.3 and 22 extend upwardly through :stop plate :34 and mounting plate 315, :and are connected at their upper ends with the plate '46 to movesuch plate upwardly .and downwardly responsive to movement of the pistons in the cylinders 2&3 and 22 within thelimits imposed .on such zmovemient upwardly by the adjustable istop 53 .on table .5 and downwardly by the adjustable stop $5 and sleeve A9 on pressure plate 3|. The pistonssojfthe side cylinders 29 and 22 are therefore iyoked together by the vplate 41d and must move .in unison. Stops 86 and 8'! are mounted respectively on rods M and s2 and are adjustably fixed in position thereon'by suitable means such as locking collars 33 and Eldrespec-tively.

The lower hydraulic cylinder .tl, which is mounted between the hydraul-iccylinders 2t and 22., has "mounted on the piston rod thereof an inner punch holder .QI (see Fig. .5) which is threaded for a portion of its length, as indicated at 92, and has a cavity or slot 93 formed therein at its upper end. A nut -95 is mounted on the threaded portion 92 of the punch holder SI and is lockedin predetermined position by a ring and a locking screw, indicated at Ill, and is movable into contact with the stops .853, 8?. A sleeve 98 is threaded on the punch holder SI and is held in its predetermined position by a locking ring '99. The sleeve moves in :an opening in the pressure plate 3| and is formed with a flange engaging the top of the plate which therefore gg-uides the punch holder '9! and limits its movement :in the downward direction.

The punch holder cavity 93 has mounted therein a core rod holder :best shown in Fig. 6. The core rod holder includes a supporting bar or bracket IB -I mounted atyits ends on the support plate 135., as by screws I32, .and extends through the cavity 93 in the punch holder 91. The bracket Ill has a threaded :hole thereth-rough, on the vertical axis of the press, into which a sleeve N3 is threaded and is locked in any desired position therein by a nut Hi4. Acore rod holder are is inserted through the sleeve IE3 and is formed withashoulder resting on the upper end of the sleeve. A lock-nut 1:01 is threaded on the lower end of the holder 1st and pulls the shoulder of the .holderagainst .the upper end of the sleeve,

byalockmut M39. The stop ring I63 may engage a shoulder .I I3 (Fig. 5) formed in the cavity 93 of the punch holder to limit the upward move .ment of the punch holder '9I by thecylinder .21 during the ejection movement of the press :in

forminga stepped piece as shown in Figure 11.

Peter now to Fig. .3 which discloses the several die parts required for making a cup-shaped piece with a central aperture therethrough. The die in the table 5] is of such size as .to :re- 1 ceive the upper punch I9 which is formed with a socket havin a vent H6 to atmosphere. The socket i It is adapted to receive the upper :end of a core rod H3 which is threadedly mounted in the end of the core rod holder I33 and is held in fixed position thereby with the upper end of the core rod flush with the table top. An inner punch or sleeve H9 fits closely around the core rod I is and is mounted in the rabbetat'the upper end of the punch holder -QI. The length of the sleeve punch H9 is such that, in the pressed position shown in the drawing in Fig. 3, the .upper end of the sleeve acts in conjunction with he lower surface of the upper punch '59 to determine the final compressed thickness .of the bottom-section of the cuppiecc being made. And the outer diameter of the sleeve punch H8 is determined by the inner diameter of the bottom of the cup piece. An outer sleeve punch 52:; is mounted in the rabbet in the punch holder 48 to extend into the die ring 56 for a distance dependent on the compacted height of the rim of the cup piece. The inner diameter of the sleeve punch are is such that the sleeve fits close" ly over the sleeve punch I I 3 and the outer diameter of the punch IE6 is a close clearance fit in the die ring 55.

The filler mechanism indicated generally at 82 in Fig, 2 is shown in elevation in Fig. 7 and in section in Figs. 8 and 9 and comprises a boxlike shoe I25 having its material-conveying portion I21 divided into substantially equal sections by partitions I2 8. The shoe length and the width are chosen to cover the entire die cavity defined by the die ring 56 and the height is so chosen that the shoe fits between the top of the rear- Wardly extending portion of the table 5! and the bottom of the hopper 83. The shoe is guided in its movement over the table by guides I29 which are fastened to the table top. The hopper is held by a hopper guide block I25 which is held down by screws I3I and the pressure of springs I39 acting on the screws extending into the table top. Movement of the .filler shoe is produced by a pressure cylinder I32 mounted on the frame SI and having its piston connected with the shoe by a universal connection shown as a ball and socket member I33. As the filler shoe I23 is retracted into the hopper guide block 125. under the bottom of the hopper 83, an opening in the hopper is uncovered and, as the active shoe portion I21 comes under the hopper, is fully opened. Upon forward movement of the shoe, the hopper opening is closed by the rear portion of the filler shoe as the active shoe portion |2| moves beyond the front hopper wall. The partitions I28 end slightly above the top of the table 5| to permit flow of the material in a leveling out action in the die cavity during both the forward stroke of the shoe and upon retraction thereof when the forward edge of the shoe passes over the die cavity. The material-conveying shoe portion carries only a constant measured quantity of material and division thereof into sections by partitions has the effect of distributing the material uniformly throughout the die cavity and of providing 001- umns of material of a constant height for filling every portion of the die cavity, thus securing uniform filling of the cavity under a constant pressure of material.

Referring now to Fig. in considering the operation of the press, the structure described performs three major functions, namely, the function of filling the die cavity, compressing the material in the die cavity, and ejecting the compressed and formed piece.

The operation of the press will be considered from the moment of ejection of a finished piece at which time the lower punches I I9 and I20 are flush with the upper surface of the die ring 5%, the end of the core rod H6 also being flush with the top of the table. The filler shoe I26 then passes beneath the opening in the hopper 03 and the several partitioned sections of the shoe portion I 21 are filled with the powdered material. The shoe then passes over the table 5| until the conveying portion I21 is over the opening in the die ring 56. The plate 39, and the outer punch I20 thereon, are then pulled down b cylinders 20 and 22 so that adjustable sleeve 46 engages sleeve 49. Plate 3| is then pushed down on 001- lars on rods 16 and pulls down the plate 56 against resistance in cylinder 61. Downward movement of plate 40 and rods III and t2 also moves the stops 86 and 81 down against the nut 96 to pull the inner lower punch I I9 down against the resistance of the upward pressure in cylinder 2| until the pressure plate 3| hits the stop rings 32. The lower punches H9 and 20 are then in the filling position and the material from the shoe portion I21 uniformly fills the die cavity.

During the time when the lower punches are being pulled down, the filler shoe moves forwardly until it comes to an abrupt stop at the end of its stroke which causes the material to be distributed uniformly in the die cavity. The filler shoe is then retracted and in its backward movement further distributes and levels off the de-- posited material, The several die parts remain in the filling position until after the filler shoe has been retracted to its former position below the opening of the hopper.

The several die parts now move in a sequence dependent on the shape of the pieceto be formed. As shown in Fig. 3, the die parts the designed to produce a cup-shaped piece with a hole through the cup bottom. The sequence of actions in forming such cup-shaped piece is as follows: The upper die 19 moves downwardly into the die cavity defined by the die ring 56 and which is closed on the bottom by the core rod [I0 and the lower punches I I9 and I20. The pressure required for compressing the powdered material is now supplied to upper punch 19 by the upper hydraulic cylinder 61 and such pressure is resisted by the cylinder 2| which holds the inner punch H9 in yielding position, and the pressure plate 3| on which the outer punch I20 now rests which holds such outer punch I 20 in stationary position. The upper die 19 continues to move downwardly, overcoming the resistance pressure in cylinder 2| and moving punch II9 on punch holder 9| down until sleeve 98 is stopped by plate 3|. The remaining downward pressure on upper punch 19 then exerts a final pressure on the piece being formed While the lower punches rest on a positive stop.

It will be seen from the above that all of the compacting pressure is obtained from the upper punch only and that the lower punches merely provide a reacting or resisting pressure. The reacting or resisting pressure is however variable, thus providing means by which the same degree of resistance may be obtained for each of the lower punches, thereby securing uniform density in all sections of the base regardless of the volume of such sections and hence of the mass of powdered material which must be compressed to secure the desired section.

The ejection operation of the press now follows and the parts move in the following sequence of steps. The plate 66 with upper punch 19 is raised which raises the pull rods 16 until the collars 15 on such rods engage the pressure plate 3| and lift the plate. Both punches I I9 and I20 are then raised as a unit by plate 3| until the upper punch 19 has reached the upper end of its stroke as set by stop ring 14 at which time inner punch I I9 is flush with the top of the table. The outer punch I20 is then moved up by the pressure acting upwardly in the cylinders 20 and 22 until the upper end of the punch is flush with the top of the table and is stopped by striking adjustable stop 63, thus completing the ejection of the molded piece from the table opening. The filler shoe again moves over the die cavity and pushes the finished piece into a carry-01f trough, refills the die cavity and withdraws. The above sequence of steps is repeated and the entire cycle of operations continues as long as the press is kept in operation.

When the piece to be made has a conical or stepped configuration as shown in Fig. 11, the sequence of operations differs as follows:

For the filling operation, the ring 96 is manually moved to a position above the stops 86 and 81, as shown in dotted position in Fig. 10. Downward pressure is then applied to the cylinder 2| which pulls the die holder 9| down until the flange on sleeve 98 engages plate 3|. When the ring 96 contacts with the stops B6 and 81, the die holder 40 and the outer sleeve punch I20 are pulled down.

In the pressing operation, the outer punch holder 40 and punch I20 are moved downwardly, as the pressure exerted on the upper punch 19 by the cylinder 61 overcomes the pressure in the cylinders 20 and 22, until sleeve 46 rests on sleeve 49.

In the ejecting operation, raising of the upper die plate 66 raises both inner punch H9 and outer punch I29 as a unit until the outer punch I20 is flush with the top of the table 5| as determined by the limit set by ring 14. The inner punch 9 then rises due to upward pressure in cylinder 2|, until the shoulder III) on the punch holder 9| strikes against ejection stop I08, this stop having been adjusted so that the upper end of punch H9 is flush with the table top to com- '9 plete the ejection process when shoulder engages: the stop.

In forming both the cup-shaped piece of Figures 3 and and the stepped piece of Figure 11, the ring 14 constitutes the principal or main stop for the plate 66 during the ejection movement of this plate. For the cup-shaped piece of iFigures 3v and 10, the subsidiary stop 63 limits. the upward movement of the outer punch I20 under the action of cylinders 20, 22, after the main stop 14 has arrested the upward movementofj the plate 66. In forming the stepped piece of Figure, 11, the subsidiary stop H38 limits the upward movement of the inner punch I I9 under the action of cylinder 2| after the upward movement of plate 66 has been arrested by the main stop 14.

It will be seen that the above construction provides a base on which is mounted a main press frame and a subsidiary frame for receiving and enclosing portions of the hydraulic drive of the press. and supporting the filler mechanism. The main frame of the press includes posts set in a lower frame block and extending upwardly therefrom and joined at their upper ends by a head plate. A plurality of motor means, which are shown as fluid pressure actuated cylinders, are mounted in the lower portion of the frame and the two side motors or cylinders are interconnected with a holder for a lower outer die while the center motor or cylinder is connected with a holder for a lower inner die.

The lower outer die holder includes a plate guided on the frame corner posts, the die holder plate being connected by means of rods with, the pistons of the side cylinders. The lower inner die holder has a rod-like member mounted on the piston rod of the center cylinder and extending upwardly through an opening in the pressure plate and the plate of the outer die holder. The inner die holder rod member engages the pressure plate upon its movementin downward direction and the rods of the outer die holder have members moving in the path of movement of a ring on the inner die holder member to secure simultaneous movement of both die holders, after partial movement of the outer die holder, in a direction determined by the type of piece being made. The inner die holder is provided with a, slotted cavity through which a fixed bracket bar extends and in which is mounted a holder for a die core rod which is adjustably mounted in the bracket bar.

The die ring in which the powdered material is compressed is formed by a removable member set into an opening in a table fixed on the press frame, the table being provided with means for controlling the upward movement of the outer lower punch holder during the ejecting action of the press. The pressure exerted on the material to be compacted is obtained from motor means, also shown as a fluid pressure cylinder, mounted in the head plate of the frame and acting on an upper punch holder by which an upper punch is moved down into the mold cavity. The upper punch holder is provided with means for engaging with the pressure plate of the lower punch holders for raising both lower punch holders simultaneously during the initial portion of the ejecting action of thepress.

The mechanism for filling'the, die cavity in the table includes a reciprocating filler shoe provided with partitions by which equal columns of material are supplied to the several portions of the die cavity. Reciprocation of the filler mechanism is produced by motormeans also shown as 10 a fluid pressure cylinder which is controlled to stop abruptly at the end of the forward stroke and the filler shoe itself acts as a gate in the bottom of the hopper for filling the shoe.

A constant measured quantity of material divided into columns of the same area and height is supplied to the die cavity, thus filling the cavity under a constant pressure regardless of the material in the hopper. The filling mechanism secures positive placing of the material throughout the entire cavity and the filling portion of the shoe insures uniformity in distribution of the material throughout the cavity. The filler shoe is made to. secure a preliminary leveling action of the material. in the cavity upon the forward stroke and to secure a final levelin action of the material in the cavity upon the return stroke.

During the pressing and compacting operations a constant predetermined pressure is exerted by the top punch against the yielding hydraulic resistance of either the center or the side of the lower pressure cylinders, dependent on the type of piece being made, during the greater portion of the pressure stroke. Such resistance may of course be varied as desired to obtain the same density in the compacted article regardless of varying cross sections thereof. The final compacting is obtained by pressing the piece against the same positive mechanical stop for the lower dies. The ejecting dieparts move simultaneously during a portion of their ejecting movement due to engagement with the same mechanical means, thus securing lifting of the piece over substan" tially its entire area during at least that portion of the ejecting action when differential movement of the die partsmight cause breakage of the compacted piece.

Although the present invention has been illustrated and described as having die parts including a stationary die ring, one upper punch, two lower punches, and a stationary core rod, it will be understood that the use of both two or more upper punches and three or more lower punches, either separately or jointly, are within the scope of the invention.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications, may be made therein Without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. In a press for compacting powdered materials, a frame, a plurality of fluid pressure motors, mounted on the frame, a plurality of upper and lower punch holders mounted on the frame independently and severally actuated by the motors, punches mounted in the holders, a table fixed on the frame and providing a mold for receiving the powdered material and the punches for compacting the same, means holding the lower punch holders in an upper position, and means mechanically interlinking the several punch holders for moving all of the lower punches downward into a material-receiving position by the power for operating one of said punch holders only.

2. In a press for compacting powdered materials, a frame, a plurality of fluid pressure motors mounted on the frame, a plurality of upper and lower punch holders mounted on the frame independently and severally actuated by the motors,

7'5 punches mounted in the holders, a table fixedon the frame and providing a mold for receiving the powdered material and the punches for compacting the same, means holding the lower punch holders in an upper position, and means mechanically interlinking the several punch holders for moving all of the lower punches downwardly into a material-receiving position by the power for operating one of said punch holders only moving in one direction.

3. In a press for compacting powdered materials, a frame, a plurality of fluid pressure actuated motors mounted on the frame, a plurality of upper and lower punch holders mounted on the frame independently and severally actuated by the motors, punches mounted in the holders, a table fixed on the frame and providing a mold for receiving the powdered material and the punches for compacting the same, means holding the lower punch holders in an upper position, and means mechanically interlinking the several punch holders for moving all of the lower punches downwardly into a material-receiving position in a predetermined sequence upon movement of only one of the punch holders in one direction.

4. In a press for compacting powdered materials, a frame, a plurality of motors mounted on the frame, a plurality of punch holders mounted on the frame and severally actuated by the motors, a table fixed on the frame and providing a mold receiving the powdered material, the punch holders being mounted for movement toward the table, a movable plate mounted on the frame and engageable by one of the punch holders for limited movement of said plate in one direction, and means extending between the punch holders for interengagement of such holders whereby movement of one of the punch holders in one direction produces movement of another of the punch holders until stopped by the plate.

5. In a press for compacting powdered materials, a frame, an upper punch holder movably mounted on the frame, a plurality of lower punch holders movably mounted on the frame, a plurality of motors mounted on the frame and connected severally with the punch holders, a table fixed on the frame and providing a mold receiving the powdered material, a movable plate mounted on the frame for engagement with one of the lower punch holders and being movable through a limited movement in one direction by said one punch holder, means extending from the upper punch holder and engageable with the plate for movement of the plate in the opposite direction, and mean extending from the lower punch holders for interengagement and move ment of one thereof by the other thereof.

6. In a press for compacting materials, a frame, a plurality of fluid pressure actuated motors mounted on the frame, a plurality of punch holders mounted on the frame and severally connected with the motors, a table fixed on the frame and providing a mold receiving the powdered material, and means for limiting movement of all but one of the motors, the one of the motors exerting the final compacting pressure against all the others of the motors when moved to their limit position.

'7. In a press for compacting materials, a frame, a plurality of fluid pressure actuated motors mounted on the frame, a plurality of punch holders mounted on the frame and severally connected with the motors, a, table fixed on the frame and providing a mold receiving the powdered material, and means for limiting movement f all but one of the motors, one of the motors ex erting the initial compacting pressure against a second one of the motors in the limit position and against the fluid pressure in a third one of the motors.

8. In a press for compacting materials, a frame, a plurality of fluid pressure actuated motors mounted on the frame, a plurality of punch holders mounted on the frame and severally con} nected with the motors, a table fixed on the frame and providing a mold receiving the powdered material, and means for sequentially limiting movement of all but one of the motors, the one of the motors exerting the initial "compacting pressure against another of the motors in the limit position and against the fluid pressure in still another of the motors and exerting the final compacting pressure against both the said other motors in the limit position.

9. In a press for compacting powdered materials, a frame, a plurality of fluid pressure operated motors fixed in the lower part of the frame, a plurality of lower punch holders severally and individually actuated by the lower motors, a fluid pressure operated motor fixed in the upper 'por-' tion of the frame, an upper punch holder actuated by the upper motor, a table fixed on the frame and having an opening therethrough forming a mold for the'powdered material, and a movable plate mounted on the frame and limited thereby in its movement in one direction, the plate being engageable by the lower punch holders, the upper motor pressing the powdered material against the resistanceto movement of one of the lower motors until the lower punch actuated by said one lower motor rests on the plate.

10. In a press for compacting powdered materials, a frame, a plurality of lower punch holders movably guided in the frame, a motor mounted in the lower portion of the frame for actuating one of the punch holders, a motor mounted in a lower portion of the frame and individually actuating another of the punch holders, an upper motor, an upper punch holder actuated by the upper motor, a table mounted on the frame and having an opening therethrough for receiving the powdered material, the lower punch holders moving independently of each other for a portion of their stroke in one direction, a plate engageable with one of the lower punch holders and limiting downward movement of said one lower punch holder and having an opening therethrough, another of the lower punch holders extending through the opening in the plate, and a sleeve on the portion of the punch holder extending through the plate opening and engageable with the plate for limiting downward movement of the said second punch holder.

11. In a press for compacting powdered materials, a frame, a plurality of fluid pressure operated motors mounted in the lower portion of the frame, a lower outer punch holder movably mounted in the frame and actuated by one of the motors, a lower inner punch holder movably mounted on the frame and actuated by another motor, a core holder adjustably fixed on the frame, a table fixed on the frame and providing a mold and die cavity, an upper punch holder movably mounted on the frame, a fluid pressure operated motor for actuating the upper punch holder, and a movable plate movably mounted on the frame and limited thereby in its downward movement, the plate being engageable by the lower punch holders, the upper motor pressazscaecr tors, punches, mounted in the holders, a table; mounted on the frame and providing a moldforreceiving the powdered material and, the punches for. compacting the same, and; means for mechanically interlinking, the several punch. holders.

upon movement of one thereof for moving others of the punches into ejecting position.

13. In a pressv for compacting powdered! material-s, a frame, a plurality of fluid. pressure operated motors mounted on the frame, a plurality; of punch holders mounted on the frame; and severally actuated by the motors, punches mounted in the holders, a table fixed on the frame and providing, a mold for receiving. the

powdered material and the punches for compacting the same, a plate movably mounted on the: frame: independently ofsaid punch holders and extending into the path of movement of some of the punch holders, and means interlinking the plate with one of the motors for movement: thereby in one direction, the plate being adapted to engage some of the punch ho1ders for simultaneous'movement thereof until one of the punches is. in, ejectingposition.

14. In a press for compacting powdered materials, a frame, a plurality of fluid pressure operated motors mounted on the. frame, a plurality of punch holders mounted on the frame and severally actuated by the motors, punches mounted in the holders, a table fixed on the frame and providing a mold receiving the powdered material and the punches for compacting the same, a plate movably mounted on the frame, on one side of the table for movement in one direction and engageable with all of the punch holders on the said one side of the table for movement in the said one directionof plate movement, and means interlinking the plate with one of the motors for movement thereby in said one direction, the plate engaging with some, of the punch holders for simultaneous. movement thereof until one of the punches is in ejecting position, another of the. motors completing movement of one of the. punches into ejecting position.

15. In a press; for compacting powdered materials, a frame, an upper punch. holder movably mounted on the frame, a plurality of lower punch holders movably mounted on the frame, a plurality of motors mounted on the frame and connected severall with the punch holders, punches mounted in the holders, a table; fixed on the frame and providing a mold receiving the powdered material and the punches for compacting the same, a movable plate mounted on the frame, and a lost motion connection between the upper motor andthe plate for moving, the. latter in one direction, the plate engaging. the lower punch holders for simultaneous movement thereof until oneof the punches is in position for ejecting the compacted piece.

16. In a press for compacting. powdered materials, a frame, a plurality of lower punch holders movably guided in the frame, a. fluid pres.- sure operated. motor mounted in the lower por.-. tion of the frame for actuating one of the holders, another fluid pressure operated motor mounted in alower portion of theframe' for in? dividiially actuating another of" the punch holders, an upper fluid pressure operated motor, an. upper punch holder actuated by the upper motor, a table mounted on the frame and havin securing simultaneous movement of all of the punch holders; by the;- upper punch holder during a portion of their stroke, the lower. punch; holders moving; independently of each other for a portion of their-stroke.

17. In a, press forcompacting powdered material, a frame, a plurality of lower: punch hold-- ers movably guided in the frame, a motor mounted in the lower portion of the frame for actuating one of the punch holders, asecond motor mounted in thelower portion of the frame and individually actuating another of the punch holders, an upper motor, anupper punch holder actuated by the upper motor, a table mounted on the frame and having an opening; therein for receiving thepowdered material, a movable plate engageable with one of the lower punch holders and. limiting movement thereof in one direction, and means on another of the lower punchholders and engageable withthe plate for movement therewith inthe opposite direction.

18. In a press for compacting powdered material, a frame, a plurality of lower punch hold-- ers movably mounted in the frame, a motor mounted in. the lower portion of the frame for acuating one of the punch holders, another motor mounted in the lower portion of the frame for. actuating another of the punch. holders, anupper motor, anxupper punch holder actuated by the upper motor, a table.- mounted on the frame and having anopening therein for receiving the powdered material, a. movable plate mounted onv the frame: for. limitedmovement thereon and having a portion. engageable with one of the lower punch holders, and a sleeve on another of the lower punch holders and engageable. with the plate for movement thereby in one direction.

19.. In a press for compacting powdered material, a frame, a plurality of lower punch hold ers movably mounted in the frame, a motor mounted in the lower portion of the frame for actuating one. of. the punch holders, a second motor mounted: in the lower portion of the frame. for actuating another of the punch holders, an upper motor, an, upper punch holder actuatedby the, upper motor, a table mounted on the frame and. having an opening therein for receiving the powdered material, and a movable plate mounted on the frame for simultaneously engaging. withv the, lower punch holders upon movemerit. in one. direction and limiting. movement of the lower punch holders in. the other direction.

20.. In a press for compacting. powdered material, a frame, a. plurality of lower punch holders movably guided in the frame, a motor mounted in the. lowerv portion ofthe frame for actuating one. of the punch holders, a second motor mounted in the lower portion of the frame for individually actuating another of thepunch holders, anupper motor, anupper punch holder actuated by the. upper motor, a table-mounted onv the frame and having. an opening therethroughvv for receiving the powderedmaterial, the lower punch holders moving independently for a portion of their stroke, a movable plate mounted on the frame,.means. connecting the upper punchv holder withthe plate. for lifting of the plate. by the upper punch holder, and means for engaging the lower punch holders with the plate for movement of the lower punch holders in the lifting direction.

21. In a press for compacting powdered materials, a frame, a plurality of lower punch holders movably guided in the frame, a motor mounted in the lower portion of the frame for actuating one of the punch holders, a second motor mounted in the lower portion of the frame for actuating another of the punch holders, an upper motor, an upper punch holder actuated by the upper motor, a table mounted on the frame and having an opening therethrough for receiving the powdered material, the lower punch holders moving independently of each other for a portion of their stroke, a movable plate engageable with one of the lower punch holders and limiting downward movement of said one lower punch holder, a means on a second lower punch holder and engageable with the plate for limiting downward movement of the said second lower punch holder, and rods extending from the upper punch holder through the plate for lifting the plate upon raising of the upper punch holder.

22. In a press for powdered solids, a frame, a table immovably mounted on the frame and having an opening therethrough defining a portion of a die cavity, a plurality of punches movable in and into the table opening, a plurality of fluid pressure motors actuating the punches, a plate movably mounted on the frame and limited thereby in its movement in one direction, stops shifted by the-motor actuating one of the punches and engaging with and moving another of the punches, and means extending from a third 1 punch and engageable with the plate for movement of the third punch thereby upon movement of the plate in one direction.

23. In a press for powdered solids, a frame, a table immovably mounted on the frame and having an opening therethrough defining a portion of a die cavity, a plurality of lower punches and an upper punch movable in and into the table opening, a plurality of fluid pressure motors severally actuating the punches, a plate movably mounted on the frame and limited thereby in its movement in one direction, stops shifted by the motor actuating one of the lower punches for engaging with and moving another of the lower punches, and means connected with the upper punch and engaging with the plate for movement of the upper punch thereby upon movement of the plate in one direction.

24. In a press for powdered solids, a frame, a table immovably mounted on the frame and having an opening therethrough defining a portion of a die cavity, a plurality of punches movable in and into the table opening, a plurality of fluid pressure motors actuating the punches in one direction of movement, a plate movably mounted on the frame and limited thereby in its movement in one direction, stops shifted by the motor actuating one of the punches and engaging with and moving another of the punches against the resistance of fluid pressure in its motor acting in the opposite direction, and rods extending from a third punch and engageable with the plate for movement of the said third punch upon movement of the plate in one direction and against the resistance of fluid pressure in its motor acting in the opposite direction.

25. In a press for powdered solids, a frame, a table immovably mounted on the frame and having an opening therethrough defining a portion of a die cavity, a plurality of lower punches and anupper punch movable in and into the table opening, a plurality of fluid pressure motors actuating the punches, a plate movably mounted on the frame and limited thereby in its movement in one direction, the plate limiting movement of the lower punches in one direction, stops shifted;

by the motor actuating one of the lower punches and engaging a second of the lower punches for movement of said second punch until stopped by the plate, and rods connected with the upper punch and extending through the plate, the rods having means thereon engaging with the plate in one direction of movement thereof and moving the upper punch in one direction upon such engagement.

26. In a press for finely divided materials, a frame, a table fixed on the frame and having an opening therethrough partially defining a die cavity, a plurality of punches movable in and into the table opening, a plurality of fluid pressure motors actuating the punches, a plate mounted on the frame for movement in one direction from a predetermined location, and a sleeve connected with one of the punches and engageable with the plate upon exertion of pressure on the said one punch by another of the punches.

27. In a press for finely divided materials, a frame, a table fixed on the frame and having an opening therethrough partially defining a die cavity, a plurality of lower punches and an upper punch movable in and into the table opening, a plurality of fluid pressure motors actuating the punches, a plate mounted on the frame for movement in one direction from a given loca tion, and a sleeve connected with one of the lower punches and engageable with the plate upon exertion of pressure on the said one lower punch by the upper punch.

28. In a press for finely divided materials, a frame, a table fixed on the frame and having an opening therethrough partially defining a die cavity, a plurality of lower punches and an upper punch movable in and into the table opening, a plurality of fluid pressure motors actuating the punches, a plate mounted on the frame for movement in one direction from a given location, and a sleeve connected with one of the lower punches and engageable with the plate upon exertion of pressure on the said one lower punch by the upper punch, the motor of the said one lower punch resisting movement thereof by the upper punch until the sleeve engages the plate.

29. In a press for finely divided solids, a frame, a table fixed on the frame and partially defining a die cavity, a plurality of punches mounted on the frame and movable in and into the die cavity and completing the definition thereof, a plurality of fluid pressure motors actuating the punches, a plate movable on the frame and engageable with some of the punches, and means connected with one of the motors and engageable with the plate for moving at least one of the punches engageable by said plate upon movement of the said one motor in one direction.

30. In a press for finely divided solids, a frame, a table fixed on the frame and partially defining a die cavity, a plurality of lower punches and an upper punch, the punches being mounted on the frame and movable in and into the die cavity and completing definition thereof, a plurality of fluid pressure motors actuating the punches, a plate movable on the frame and engageable with some of the punches, and means connected with the motor for the upper punch and engageable with the plate for moving the lower punches upon movement of the said upper punch motor in one direction.

31. In a press for finely divided solids, a frame, a table fixed on the frame and partially defining a die cavity, a plurality of punches mounted on the frame and movable in and into the die cavity and completing the definition thereof, a plurality of fluid pressure motors actuating the punches, a plate movable on the frame and engageable with some of the punches, and rods connected with one of the motors and engageable with the plate for simultaneously moving some of the punches upon movement of the said one motor in one direction and until one of the lower punches reaches a predetermined position, the motor of another lower punch thereupon continuing movement of said last mentioned punch until the ends of said lower punches are at the same level.

32. In a press for compacting powdered materials, a table providing a mold cavity receiving the powdered material, a plurality of independently movable punches mounted on movable holders arranged on opposite sides of the table for movement into and out of the mold, a plurality of motors for severally moving the punch holders, a plate limiting movement in one direction of the punch holders on one side of the table, and means for bringing the punch holders on one side of the table into contact with the plate in a predetermined sequence of actions.

33. In a press for compacting powdered materials, a table providing a mold cavity receiving the powdered material, a plurality of independently movable punches mounted on movable holders arranged on opposite sides of the table for movement into and out of the mold, a plurality of motors for severally moving the punch holders, a plate limiting movement in one direction of the punch holders on one side of the table, and means forbringing the punch holders on one side of the table into contact with the plate in a predetermined sequence of actions, movement of one punch holder bringing the plate into its limit position and bringing a second punch holder into contact with the plate against the resistance of the second punch motor to maintain a given positioning of the punches in the mold during reception of the owdered material.

34. In a press for compacting powdered materials, a frame, a plurality of lower punch holders movably guided in the frame, a motor "mounted in the lower portion of the frame for actuating one of the punch holders, a second motor mounted in the lower portion of the frame and individually actuating another of the punch holders, an upper motor, an upper punch holder actuated by the upper motor, a table mounted on the frame and having an opening therethrough for receiving the powdered material, the lower punch holders moving independently of each other for a portion of their stroke in the direction for ejecting the material from the mold after compaction, means mounted on the frame for engagement with one of the lower punch holders and limiting downward movement thereof, and means mounted on the second of the said lower punch holders for engagement with the first said means and limiting downward movement of the second lower punch.

35. In a molding press for forming molded articles, the combination of a die having a vertical bore, a plurality of independently movable plungers positioned in the lower end of the bore of said die, means for maintaining the ends of two of said plungers in fixed relative positions at dilferent levels during compression of said article into final shape, and means for ejecting said article from said bore including means for moving said plungers through said bore while maintaining the same relative compression levels of said plungers to initiate the ejection of said article, and means for thereafter leveling the ends of said plungers in the plane of the upper end of said die.

36. In a molding press for forming articles of compressed material, the combination of a die, a plurality of independently movable plungers positioned in the lower end of the bore of said die, an upper plunger arranged to enter the upper end of said die, means for effecting rela tive movement between said upper plunger and said lower plungers to compress an article into final form where the ends of at least two of said lower plungers are at different levels, and

including means for moving said two lower plungers in said bore while maintaining the same relative compression levels of the ends thereof to initiate the ejection of said article, and means for thereafter leveling the ends of said two plungers in the plane of the upper endv of said die.

3'7. In a molding press for forming articles of compressed material, the combination of a die,

a pair of independently movable plungers -posi-.

tioned in the lower end of the bore of said die,

an upper plunger arranged to enter the upper. end of said die, means rigidly supporting one of said lower plungers with its upper'end .at a certain level within said die, means yieldably supporting the other lower plunger with its upper end located at a higher level than said one lower plunger, means for filling said die with molding material, means for actuating said upper plunger to compress said material in said die, said actuating means operating to depress said yieldably supported lower plunger by pressure applied through said molding'ma-terial, and a stop for limiting the downward movement of said yieldably supported plunger at'a level above the level of said one plunger.

38. In a molding press for forming articles of compressed material, the combination of a table having a die bore formed therein, a pair of independently movable plungers arranged below said table and having their upper ends positioned to enter the lower end of said bore, an upper plunger arranged to enter the upper end of said bore, a movable stop arranged below said table and mounted for vertical movement between a lower position and an upper position, said stop in its lower position forming a common seat for supporting said lower plungers in fixed relation to determine the final form of the molded article where the ends of said lower plungers are at different levels, means yieldably supporting the uppermost of said lower plungers in an elevated position with respect to said stop to define the die cavity in said bore for receiving molding material, means for supplying molding material to said cavity, means for actuating said upper plunger to compress the material within said cavity, said actuating means operating to depress said yieldably supported lower plunger by pressure applied through said molding material until said yieldably supported plunger is seated against said stop, means for withdrawing the upper plunger, and means operated in timed relation with the withdrawal of the upper plunger for raising said movable stop to initiate the ejection of said molded article.

39. In a molding press for forming articles of compressed material, the combination of a die, a plurality of independently movable punches positioned in the lower end of the bore of said die, means yieldably supporting one of said lower punches in a raised position, an upper punch arranged to enter the upper end of said die, means for effecting relative movement between said upper punch and said lower punches to compress an article into final form where the ends of at least two of said lower punches are at different levels, said yieldably supported punch being depressed from its raised position by pressure applied through the molding material, and means for ejecting said article from said bore including means for producing relative movement between said die and said two lower punches while maintaining the same relative compression levels of the ends of said two lower punches to initiate the ejection of said article through the upper end of said die, and means for thereafter leveling the ends of said two punches in the plane of the upper end of said die.

40. In a molding press, the combination of a frame, a die element mounted within said frame and having a vertical bore, a pair of lower punches positioned within the lower end of the die bore, separate holders for said lower punches mounted within said frame for independent vertical movement, a plate mounted in said frame for vertical movement from a loading position to an ejecting position, yieldable fluid pressure means normally holding said plate in loading position, stop means interconnecting each of said lower punch holders with said plate to maintain said lower punches at different loading levels, motor means for moving said plate into ejecting position, and mechanical interlocking means interconnecting said plate and said lower punch holders for moving both of said punch holders by the movement of said plate from its loading position towards its ejecting position.

41. In a molding press, the combination of a frame, a die element having a vertical bore, an upper punch element, a plate mounted upon said frame for vertical movement and supporting one of said elements, a pair of lower punches positioned within the lower end of the die bore, separate holders for said lower punches mounted within said frame for independent vertical movement below said plate, fluid pressure motor means for moving said plate between an upper position and a lower position, and a lost-motion connection between said plate and said lower punch holders for suspending both of said punch holders from said plate and thereby moving both of said lower punches upwardly by movement of said plate, after said plate moves upwardly a predetermined distance from its lower position. 42. In a molding press, the combination of a frame, a die element having a vertical bore, an upper punch element, a plate mounted upon said frame for vertical movement therein and supporting one of said elements, a pair of lower punches positioned within the lower end of the die bore, separate holders for said lower punches mounted within said frame for independent vertical movement below said plate, fluid pressure motor means for moving said plate in a direction to separate said upper punch and said die element and to eifect relative movement between said die element and said lower punches in a direction to eject a molded piece from the top of said die element, and individual stops for said lower punch holders for stopping said relative movement when the end of each lower punch becomes flush with the upper end of said die.

JACK E. WEIDNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 994,349 Updegrafi June 6, 1911 1,839,056 Short Dec. 29, 1931 1,858,225 Frederick May 10', 1932 1,971,850 Ernst Aug. 28, 1934 1,972,789 Newkirk Sept. 4, 1934 1,982,576 Derry Nov. 27, 1934 2,122,874 Whipple July 5, 1938 2,209,404 Lassman July 30, 1940 2,325,687 Kux Aug. 3, 1943 2,332,938 Sohmidberger Oct. 26, 1943 2,350,971 Pecker et al. June 6, 1944 2,499,980 Stokes, Jr., et al. Mar. 7, 1950

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