WO2002040204A2 - Hydraulic modular manufacturing system - Google Patents

Abstract

A modular manufacturing system for manufacturing parts includes at least one force application assembly and at least one punch or tool. This punch is driven by a force application assembly which directly applies a force to the force receiving end of the punch without involving a single adapter. The tool, or the press, requires neither the presence of conventional press plates nor that of a bulky external frame.

Description

HYDRAULIC MODULAR MANUFACTURING SYSTEM This is a Continuation-in-Part of the U.S. Patent Application that was filed on November 10, 2000, which is in turn a Continuation-in-Part of U.S. Patent Application No. 09/503,543 filed on February 14, 2000, which in turn claims benefit from Provisional Patent Application No. 60/146,422 filed on July 29, 1999.

Field of the Invention This invention relates to a manufacturing system for forming a work piece from materials and, in particular, a manufacturing system that comprises an independent power source and at least one manufacturing assembly associated therewith. Background of the Invention

In the field of powder metallurgy, fine metal powders are compressed into the form of a work piece in a die under high pressure. The procedure is typically carried out in huge oversized machines referred to as powder presses. In these- presses, pressure is applied to t'he metal powder by at least one movable punch. The pressure applied to the work piece by way of the punch, or punches, can be applied, for example, mechanically or through the use of hydraulic rams. An example of a powder press using a hydraulic ram is shown in U.S. Patent No. 3,788,787 to Silbereisen et al . Silbereisen et al . involves a powder press having a vertical orientation and upper and lower hydraulic cylinder assemblies. The upper hydraulic cylinder assembly is connected to a massive cross head, or platen. A press punch, is in turn connected to the cross head and moves downwardly into a mold cavity in the die. This action presses the metal powder within the die to form a compressed solid work piece having the desired height and shape. A lower punch is fixed relative to the frame. The Silbereisen, et al. press is representative of powder preπseπ presently known in HIP art: .in I'hnl 1) it in ϋiηnotl to accommodate a variety of different work pieces by allowing for interchangeability of the tool matrix or die and 2) the distance the ram(s) travels or ^,λ stroke" is relatively fixed. In this ^generic" press it is therefore necessary to compensate for the ^v>fixed" stroke by adapting the tool and die and appropriately connecting them to the ram(s) in order to produce a given part or work piece. Such adaptation typically involves large structure and results in large distances between the source of force moving the ram and the actual part being produced. These large distances then translate into inaccuracies in alignment between the punches when they reach the die to form the work piece. The powder from which the work piece is formed is conventionally introduced to the die by a powder feed shoe that allows powder to fall gravitationally into the open upper end of the die as the feed shoe travels across the die. As the powder is compressed by the punches, density gradations in the powder create shear forces within the powder. To contain the shear forces and other forces created by misalignment of the punches, conventional presses rely on large overall size and weight and on massive moving platens to maintain proper alignment during operation. In particular, the platens of conventional presses and the frame members holding and guiding the platens, are also very large and very heavy in order to maintain proper alignment of the .punches and the die. Because of the tremendous forces employed in the press, any misalignment can cause catastrophic failure of the press. As a result of all this required additional structure, presses of this type typically stand greater than 20 feet high and weigh more than 50 tons.

Further contributing to the massive size of these presses is an ^integrated energy source. That is, each press has its own built in energy source that typically is very large considering the amount of energy needed to press a work piece. A commercially available hydraulic automatic press known as the TPA H manufactured by Dorst Maschen und Anlagebau readily illustrates the massive size of these conventional presses. The TPA H press provides, at the lower end of the press, a first hydraulic cylinder fixed relative to the frame of the press and having a first piston that moves vertically within the first hydraulic cylinder. A second piston moves vertically within the first piston such that the first piston acts as a second hydraulic cylinder within which the second piston operates. The TPA H press also provides an upper hydraulic cylinder fixed relative to the frame of the press. The upper hydraulic cylinder has an upper piston that moves vertically relative to the upper hydraulic cylinder.

Similarly to those of other conventional presses, the punches used with the TPA H press are spatially separate from the various hydraulic pistons and are held in position by large platens. Hence, this press has, as is typical with other conventional presses, a source of energy for moving the punches at a remote location from the energy or force receiving end of the punch. This press also has a large external frame to compensate for the shear forces on the powder and the misalignment of the punches due to large travel distances.

The moving mechanism in a typical press can be, as in Silbereisen, et al . , a hydraulic piston cylinder mechanism. Further drawbacks to the typical powder press as shown in Silbereisen, et al . include the requirement for an extensive set-up procedure prior to starting a production run for a given work piece. During set-up^'» the various punches and the die must be properly aligned relative to one another and attached to their respective platens. In addition, movement of the platens must be coordinated such that the powder in the die is compressed at a predetermined rate by each punch. Such coordination usually results in different platens moving at different rates for different periods of time. Therefore, set-up is a time consuming operation that can take one to three _cdays to complete and must be performed by highly skilled operators. When the next work piece is to be^' made, the press must be disassembled and reassembled, resulting in a significant down time for the entire press.

This need for massive platens movable relative to one another and thus the requirement of long punches, and the requirement for sufficient floor space to permit assembly and disassembly, further adds to the massive size of the presses, which can be around 25 or more feet high. They also involve a, large number of massive, relatively moving parts whose movements must be precisely controlled, with the result that they are very complex and very expensive, and can cost for example, more than a million dollars for a single press. These presses are typically installed with their bases at least 6 feet underground and require reinforced foundations. Also, frequent breakage of parts during assembly and disassembly results in added costs associated with the conventional press. Each conventional press is manufactured as a specific size, for example, 220 ton, 750 ton, etc., each size having the ability to make only a certain range of parts. Further, the large distances between moving parts of conventional presses magnifies the effect of manufacturing tolerances. As a result, very large pieces of conventional presses must be manufactured to very tight tolerances, making manufacture of these pieces very expensive. Additionally, as discussed above, each conventional press has an integrated force producing assembly. All of these factors contribute to high operating costs that must eventually be recouped in the price of the work pieces produced. Moreover, these conventional powder presses are considered to be permanent fixtures and lack any kind of portability. Summary of the Invention

An apparatus and manufacturing system of the present invention perform the pressing function of conventional presses such as powder, stamping, die casting, injection molding, etc. while, at the same time, allowing the use of a substantially smaller, lighter, portable and less expensive apparatus than conventional presses and manu acturing systems. A manufacturing module of the present invention can be about 12 ind es in diameter and about 28 inches long, for example, as opposed to about 25 feet high and about six feet across for a conventional press. A manufacturing module of the present invention can be manufactured to produce one specific work piece and therefore need not be adjustable thereby requiring long down times to set-up or in some embodiments, the present invention press can be manufactured to produce one specific work piece for an ] onq nπ nff rl nnrl Ihon retooled to produce another work piece. Moreover, tlie present invention manufacturing systems have manufacturing modules that are remote from independent power sources such that a number of raodulss can be attached to one power source, greatly conserving resources and space. The greatly reduced size, weight and complexity of a press of the present invention allows a manufacturing system to take up much less physical space than multiple conventional free standing integrated presses .

The press module of the present invention has a substantially simplified structure. In embodiments of this invention, the motive force is applied directly to a force ■ receiving end of one or more punches without the need for intervening platens. The punches are preferably monolithic devices that include a work-pressing end and a force-receiving end, although in some embodiments interchangeable work pressing attachments are provided at the work piece forming end of the punch. In embodiments involving a plurality of punches moving in the same direction during formation of a work piece, the force applying mechanism for one punch is preferably axially fixed relative to the force applying mechanism for another punch. For example, each punch is preferably associated with a hydraulic cylinder, with the plurality of hydraulic cylinders {being fixed relative to one another. Particularly in embodiments comprising a plurality of coaxial hydraulic cylinders, adjacent cylinders may be in contact with and attached to one ^' another to provide a particularly compact arrangement. The present invention press module optionally includes means for creating a substantially uniform distribution of powder in the die. By including such means the powder in the die can be pressed relatively squarely and perpendicularly, reducing the requirement for huge platens and structure to maintain alignment of the press during pressing. Add to this the relatively short distances the punches of the present invention travel in forming the work piece and the result is the virtual elimination of shear forces on the powder during pressing. This contributes to more precise part geometries and tolerances .

Brief Description of the Drawings The foregoing and further objects, features and advantages of the present invention will be described in or be apparent from the following description of embodiments, with , reference to the accompanying drawings, where like numerals are used to represent like elements and wherein:

Fig. 1 is a schematic drawing of a pressing assembly according to the present invention; and Fig. 2 is a sectional view of a press of the invention wherein the die is stationary.

Fig. 3 is a sectional view of a press of the invention wherein the die is movable.

Fig. 4 is a sectional view of an alternate embodiment of the invention wherein the force receiving pistons and respective cylinders are mounted concentrically with respect to each othe .

Fig. 5 is a sectional view of a single piston, associated die rods, cylinder head plate, and punch plate for a press with concentrically mounted force receiving pistons and cylinders .

Fig. 6 is a sectional view of an alternate embodiment of the invention for casting fluid material in a closed mold.

Fig. 7 is a sectional view of an alternate embodiment of the invention showing a single station for cold working material .

Fig. 8 is a sectional view of an alternate embodiment of the invention for hot working material.

Fig. 9 is a sectional view 'of an alternate embodiment of the invention for bending material .

Fig. 10 is a sectional view of an alternate embodiment of the invention incorporating a channel through the piston rod for the delivery of particulate material to the die.

* Detailed Description of Preferred Embodiments In an embodiment of the present invention a powder press manufacturing system is comprised of an independent power source and at least one pressing module remotely associated therewith. Each pressing module is comprised of at least one punch having an end for pressing a powder material to form a work piece. At least one punch is operatively associated with a first end of a piston having a second force receiving end. In one embodiment, the punch that is operatively associated with the first end of the piston is removable therefrom. Alternatively, the punch that is operatively associated with,. the first end of the piston comprises a single monolithic part .

There is at least one force applying assembly configured to apply pressing force directly to the force receiving end. ^'Each force applying assembly applies force to the force receiving end portion of a punch along the axis of the punch. Each force applying assembly is preferably axially fixed relative to a frame so that it cannot move along the axis of the punch. Some or all of the force applying assembly can be, for example, a hydraulic force applying assembly, a pneumatic assembly or mechanical force applying assembly. In a particularly preferred embodiment, the force applying assembly of the pressing module is a hydraulic assembly.

Each pressing module is operatively and reciprocally connected to and receives power from the independent power source. The pressing module further comprises a die to receive and contain the powder. The material from which the work piece is formed when using the powder pressing module can be, for example, metal powders, ceramic powders, other powders, flakes, fibers or sheets of ceramics, polymers, carbides, cements or the like. For ease of reference throughout the specification and claims, such materials are referred to as "powders." The die has an opening positioned to receive the end of the punch. 'The pressing module can further comprise means for delivering powder into the die and creating a substantially uniform distribution of powder in the die. Preferably, the means for creating a substantially uniform distribution comprises a powder fluidizing apparatus, preferably, the manufacturing system according to the present invention comprises a plurality of pressing modules remotely associated with the independent power source. There is at least one pressing station remotely connected to the power source, wherein each of the pressing modules is removably attached respectively. The manufacturing system according to the present invention further comprises at least one controller associated with each pressing module . The controller controls the distribution of power from the independent power source to each of the stations. There is a computer interface associated _fwith. that controller. The controller controls the distribution of power from independent power source by controlling hydraulic fluid delivery to and removal from the force applying assembly associated with the pistons. The manufacturing system can be operated wherein the controller controls the rate at which each piston moves towards the die so that at a point in time force/unit area² being applied to each said first surface of the work piece is the same. Likewise the manufacturing system can be operated wherein said controller controls a rate at which each piston moves towards the die so that each piston reaches the surface of the work piece at the same point in time. This also applies wherein the first piston moves toward and into the die until it moves a predetermined distance in the cylinder, a predetermined force is being applied to a first surface of the work piece and/or until a mechanical stop is reached.

The present manufacturing system can further comprise at least one second punch that extends in a second direction opposite that of the first punch and towards the die. This second punch can be fixed or alternatively it is operatively associated with a first end of at^ least one second piston having a second force receiving end.

The punches are, in some embodiments, arranged so that the work piece forming ends of one or more punches are arranged to form the same side or alternatively, opposite sides of the work piece. The long axes of the punches can be arranged horizontally, vertically or at any other angle relative to the horizon.

In an embodiment of the invention for forming a work piece the press module has at least one piston cylinder having a piston slidable within it. The piston has a force receiving end within the cylinder and a work piece forming end extending beyond the cylinder. In contrast to typical powder presses wherein the force receiving end of the punch is attached to or at least in contact with any number of adapters before engaging the motive force, in the present invention the force receiving end directly engages a motive force for sliding the piston within the first piston cylinder. This sliding within .the ςylinder acts to generate a force that is directly applied to the first surface of the work piece

The die is preferably annular but can be any shape appropriate to define the work piece being formed. The die has ^"a hole, which is positioned to receive the work piece forming end of or attachment on the piston. There is also an opening in the die to receive the powder. One or more piston cylinders can be positioned on the same side or opposite sides of the die. Therefore, the work piece forming end of a particular piston can extend in the same direction or in an opposite direction to the work piece forming ends of other pistons. Alternatively one of the pistons - the opposing one can be fixed, e.g. an anvil.

In a further embodiment the press module of the present invention further comprises at least one second piston cylinder having a second piston reciprocally slidable within it. The second piston, like the first piston, has a force receiving end located within the cylinder and a work piece forming end for forming a second surface of a work piece . The work piece forming end extends beyond the cylinder. The force receiving end directly engages a ^'motive force for sliding the piston (s) within the second piston cylinder (s) to generate a force to be applied to the first .surface of the work piece. In embodiments, a plurality of the piston cylinders are fixed relative to each other. Some of the second ends of the pistons can extend beyond their respective cylinders in the same direction, for example to provide concentric punches, while others can extend in a direction opposite the direction in which second ends of other pistons extend beyond their respective cylinders in order to press the opposite side of the work piece. Each piston cylinder and piston therein corresponds to a different level of the work piece to be formed.

Some or all of the piston cylinders can be hydraulic cylinders with the pistons being hydraulically operated. In the case of some or all of the piston cylinders being hydraulic cylinders, the piston cylinders can share a common hydraulic fluid pressure source or can have hydraulic fluid sources with the same or different pressures. The hydraulic pressμre of the hydraulic fluid delivered to each hydraulic piston may be individually controlled by separate valves. Further, the valves may be, for example, controlled by the controller. 5 Piston cylinders that are adjacent to each other can be in contact with and attached to each other. This helps enhance the compactness of the structure and permits individual parts to have multiple functions. For example, the end of a part defining a cavity of one piston cylinder may 0 .also define the head of an adjacent piston cylinder.

Additionally, in preferred embodiments, the first piston within each succeeding first piston cylinder extends through and is axially movable along an inner peripheral surface defining a cylindrical void through a directly preceding first 5 piston. Likewise, the second piston within each succeeding second piston cylinder extends through and is axially movable along an inner peripheral surface defining a cylindrical void through a directly preceding second piston.

Figs. 4-7 show an embodiment of the invention wherein the ;0 punches are hydraulic pistons and the cylinders are hydraulic cylinders in which the pistons operate.

The hydraulic fluid for the various hydraulic fluid passages and channels in the press of the present invention is pressurized, for example, by a pressure source 360 as shown in IS Fig. 1. Hydraulic fluid lines connect the pressure source to the hydraulic fluid channels, the pressing hydraulic fluid passages, the retracting hydraulic fluid passages) , the die ejection piston and the die ejection reservoir. In a preferred embodiment, the pressure source 360 has a 30 plurality of valves 371, one valve for each hydraulic fluid line 370. By selectively operating the valves 371 of the pressure source 360, the punches and the die ejection piston 510 can be selectively moved in either direction. In embodiments, the valves 371 of the pressure source 360 are 35 controlled by a microprocessor 372. For example, valves 371 may be controlled by one time/pressure curve such that each punch begins pressing at substantially the same time, stops pressing at substantially the same time and presses the powder with substantially the same pressure even though different punches can have substantially different strokes. The controller, preferably a microprocessor, controls the rate at which each piston slides within the cylinder so that at a given point in time, the force per unit area² on each surface ^'o the work piece is the same. Alternatively, the valves 371 can be controlled so that each punch slides a predetermined distance in the cylinder, until a predetermined force is being applied to the respective first surface (s) and second surface (s) of the work piece or until a mechanical stop is reached within the piston cylinder.

Figure 6 shows an alternative embodiment of the present press wherein there is one first piston cylinder 210. First piston 212 reciprocally operates within piston cylinder 210. First punch 213 for forming a first surface of a work piece 205 is operatively associated with first piston 212.

Similarly, there is one second piston cylinder 240 wherein second piston 242 operates. Second punch 215 for forming a second surface on the work piece 205 is operatively associated with second piston 242. First punch 213 has work piece forming end 223 opposite to the portion 228 at which it associates with the piston 212 and similarly second punch 215 has work piece forming end 225 opposite to the portion 231 at which it associates with piston 242. Pistons 212 and 242 respectively have retraction surface 221 and 223 and force receiving surfaces 229 and 233. First spacer cylinder 235 and second spacer cylinder 237 maintain piston cylinders 210 and 240 fixed relative to the die 310, in this embodiment fixed. Die holder cylinder 320 holds die 310 in a position to receive first <work piece forming end 223 of first piston 212 and second work piece forming end of second piston 242. First cylinder 210, first spacer cylinder 235, die holder cylinder 32o, second cylinder 240 and second spacer cylinder 237 are held by frame 10 having first end plate 12 and second end plate 14. The first end plate 10 and second end plate 14 are held together by bolts (not shown) .

In operation, starting from "fill" wherein a portion of first work piece forming end 223 of first punch 213 and a portion of second work piece forming end of second punch 215 each respectively sit inside die 310 thereby enclosing die 310 ,for containing powder material. Powder material to make a work piece is then introduced into die 310 through a conduit (not shown) and preferably fluidized. Hydraulic fluid moves through first inlet (not shown) to act on first force ^'receiving end 229 of piston 212 sliding it within first piston cylinder 210 towards die 310. At the same time hydraulic fluid moves through second inlet (not shown) to act on second force receiving end 233 of piston 242 sliding it in the direction of die 310. Powder (not shown) in die 310 is thereby compressed between the work piece forming end 223 of first punch 213 and the work piece forming end 225 of second punch 215. Second retraction surface 233 is acted upon by hydraulic fluid entering into second cylinder 240 through retraction inlet 390 thereby moving second piston 242 away from die 310. The work piece formed is ejected by further application of hydraulic fluid on the force receiving end 229 of piston 212 causing piston 212 to travel toward and through die 310 a distance that is approximately equal to the height of the work piece thereby pushing the work piece out of the die 310. As will be immediately appreciated, the process by which the press of the present invention presses and then ejects a work piece can involve any number of the above operational steps in the same or different order or combination and the invention should therefore not be construed as limited only to the above.

In preferred embodiments of the invention, the powder from which the work piece is produced is fluidized and/or pressurized to produce a substantially uniform density throughout the powder in the die during pressing. Examples of such powder fluidization and pressurization are shown in U.S. Patent No. 5,885,625, issued on March 23, 1999; U.S. Patent No. 5,945,135 issued on August 31, 1999 and U.S. Patent No. 5, 897,826 issued on April 27, 1999, which are hereby incorporated in their entirety herein by reference. Using such filling techniques, a press of the present invention can be operated with its major axis in the horizontal position, unlike conventional presses which rely mainly on gravity for their fill. Additionally, because the density of the powder is uniform in the die the press need not withstand the large shear, stresses encountered with conventional presses, the number of parts of the press may be greatly reduced (for example, approximately 30 parts, other than seals, versus approximately 2000 parts in a conventional press) . Also, the powder is isolated from the operating environment enabling the safe usage of a number of materials. Due to the compact size and reduced number of parts, a press of the invention can be produced for a fraction of the cost of a conventional press. Moreover, since the power supply for a press of the present invention is independent and external to the press, it is highly portable and can be attached and detached to the power supply as needed. While the invention, has been described by using the example of a hydraulic press with concentrically positioned punches, it should be noted that other known force producing sources and other relative punch positions can be used. For example, mechanical pressing, pneumatic pressing, piezoelectric or electromagnetism can be used to apply force to the punches. In addition, punches having work piece forming ends other than cylinders and having axes that are not concentric can be used.

The present invention is further fdirected to a method for forming a work piece. The method comprises introducing a powder material into a die, preferably creating a uniform density of powder in the die by fluidizing the powder in the die and pressing the material in the die from a first direction with a first set of at least one work piece forming punches. Operatively associating the work piece forming punches with a first set of at least one pistons and pressing the material in the die by directly applying a motive force to a force receiving end of each of the first set of at least one pistons thereby sliding each piston within a first piston cylinder in a direction towards the die. Each of the first piston cylinders is fixed relative to each other. The method can optionally further comprise the step of pressing the material in the die from "a second direction opposite the first direction with a second set of at least one work piece forming punches respectively operatively associated, with a second set of at least one pistons. Like the first set of work piece forming punches, the material is pressed in the die by directly applying a motive force to the motive force receiving end of each of the second set of at least one piston (s) thereby sliding each within a second piston cylinder in a first^, direction towards the die. Each of the second piston cylinders is also fixed relative to each other.

In this method the first and/or second direction can be along a ^'horizontal plane.

In this method the step of directly applying the motive force to the force receiving end of each of the first pistons is carried out by delivering hydraulic fluid into each of the first piston cylinders.

In a further embodiment, Fig. 3 schematically shows the present invention is directed to a modular manufacturing assembly. The assembly comprises an independent power source 1 and at least one manufacturing module 2 remotely associated therewith. Each manufacturing module 2 is comprised of at least one tool 3 to form a work piece. Preferably, the tool 3 is operatively associated with a first end of a piston having a second force receiving end. There is at least one force applying assembly configured to apply force directly to the force receiving end of the pistonv The manufacturing module 2 is operatively and reciprocally connected to and receives power from the independent power source 1. In a particularly preferred embodiment, the tool is a stamping press configured to stamp out parts or the tool is configured as a forging press. Any number of different manufacturing technologies can be used in conjunction with the modular manufacturing assembly and the invention should therefore not be construed as being limited only to forging and stamping. Fig. 4 shows an embodiment of the present invention wherein the die 950 and the die cavity 951 are stationary relative to the structure of the press 901. The structure of the press 901 is comprised of the die holder 949, an upper spacer ring 921, a lower spacer ring 920, at least a first upper cylinder 925, at least a first lower cylinder 924, an upper cylinder head 927, a lower cylinder head 926, at least three tie rods 960, and associated fasteners 961. The structure of press 901 is also comprised of second upper cylinder 923 and second lower cylinder 922. Pressure end surface 962 of first lower cylinder ^■924 is mounted against lower cylinder head interior face 918 to seal chamber 970 therein. Pressure end surface 966 of second lower cylinder 922 is mounted against retraction end surface 964 of first lower cylinder 924 so that second lower cylinder 922 is coaxially adjacent thereto and seals chamber 972 therein. Lower spacer ring 920 is coaxially adjacent to second lower cylinder 922, its cylinder side surface 956 being mounted against retraction end surface 968 of second lower cylinder 922. Die holder 949 is mounted coaxially adjacent to • ' lower spacer ring 920, with lower die holder surface 954 mounted against die side surface 958.

Upper spacer ring 921 is coaxially adjacent to die holder 949, with spacer ring's die side surface 959 bearing against upper die holder surface 955. Second upper cylinder 923 is coaxially adjacent to upper spacer ring 921, with its retraction end surface 969 bearing against cylinder side surface 957 of upper spacer ring 923. First upper cylinder 925 is coaxially adjacent to second upper cylinder 923, with its retraction end surface 965 mounted against pressure end surface 967 of second upper cylinder 923, and seals chamber 973 therein. Upper cylinder head 927 is mounted coa-ially to first upper cylinder 925, with its interior face 919 mounted against pressure end surface 963 and sealing chamber 971 therein. Any number of cylinders may be mounted to provide the structure of a press, and other embodiments of the present invention may comprise more or fewer cylinders. Passing directly between upper cylinder head 927 and lower cylinder head 926 and connecting them so as to hold or tie the structure of press 901 together is at least one and preferably a plurality of tie rods 960, and associated fasteners 961. The tie rods 960 and fasteners 961 preferably have a cross sectional area for a given tie rod material and fastener material that is able to withstand a pressure approximately equal to the sum of the respective surface areas of the force receiving ends of the pistons within the cylinders multiplied by the respective motive force being applied to each surface. These pressure values for a given tie rod material and fastener material and cross sections can be readily ascertainable . For safety reasons it is of course preferable, ,to exceed this calculated pressure by at least a factor of 2 and preferably 4. This can be done by adding tie rods and fasteners, choosing stronger materials for the tie rods and fasteners, enlarging their cross sectional areas, or any combination of these.

Because the cylinders are coaxially mounted within the structure of press 901, the punches are coaxial. Within first upper cylinder 925 is piston 941, with retraction face 911 connected to first upper punch 903, and with first upper punch face 905 affixed to its opposite end. Within first lower cylinder 924 is piston 940 connected at retraction face 910 to an end of first lower punch 902, and with first lower punch face 904 affixed to its opposite end. Within second upper cylinder 923 is piston 943 connected by its retraction face 915 to one end of second upper punch 907, with second upper punch face 909 affixed to its opposite end. Within second lower cylinder 922 is piston 942 connected by its retraction face 914 to one end of second lower punch 906, with second upper punch face 908 affixed to its opposite end. Ports 936, 932, 933, and 937 are associated with cylinders

924, 922, 923, and 925 respectively, to admit hydraulic fluid (not shown) under pressure from and outside source (not shown) into the cylinders, and to apply, force to the force receiving ends 912, 916, 917 and 913 of pistons 940, 942, 943, and 941 respectively, to cause the punches faces 904, 908, 909, and

905 to move in a direction toward die cavity 951. Ports 934, 930, 931, and 935 are associated with cylinders 924, 922, 923, and 925 respectively, to admit hydraulic fluid (not shown) under* pressure from and outside source (not shown) into the cylinders, and to apply force to the retraction faces 910, 914, 915 and 911 of pistons 940, 942, 943, and 941 respectively, to cause the punches faces 904, 908, 909, and 905 to move in a direction away from die cavity 951. In operation, particulate material 952 is introduced into the die cavity 951 while first and second lower punch faces 904, 908 form a floor in the die cavity 951 to contain particulate material 952 within die cavity 951 . Hydraulic pressure is applied to the force receiving faces 912, 913, 916, and 917 of pistons 940, 941, 942, and 943, causing punch faces 904, 905,

- 36 908, and 909 to move toward the uncompacted powder that comprises the particulate material 952 contained in die cavity ^■951. The punches enter the die cavity, compacting and consolidating the particulate material therein. Upon sufficient compaction of the particulate material, first upper punch 903 and second upper punch 907 are withdrawn by application of hydraulic pressure on retraction faces 911 and 915 until sufficient clearance is achieved for consolidated article 953 to be withdrawn from die cavity 951. Hydraulic pressure is then applied again to force receiving face 912 of first lower piston 940 and force receiving face 916 of second lower piston 942, causing consolidated article 953 to move toward the withdrawn upper punch faces 905 and 909. Hydraulic pressure is applied continuously until consolidated article 953 clears die cavity 951 and can be removed from the press

901. Upon retrieval of the finished workpiece 953, hydraulic pressure is applied to the retraction faces 910 and 914 of the lower pistons, causing the punches and die to move to the compaction procedure starting position. Because cylinders that are adjacent to each other can be in ^■ contact with and attached to eaclj. other, and shafts can be nested within each other, other embodiments of the invention may have more or fewer cylinders, pistons and punches than are

1 shown by the embodiments herein.- Moreover, certain embodiments of the present invention do not require all of the described punch and die sets.

In an alternative embodiment, both the upper and lower punches are introduced into the die cavity to a distance sufficient to allow _<the filling of each level of the die to be proportional to the finished levels of the compacted workpiece in the die cavity.

Fig. 5 shows an embodiment of the present invention wherein the die 1050 and the die cavity 1051 move axially relative to the structure of the powder metallurgy press 1001. The structure of the press 1001 is comprised of the die 1050, at least a first upper cylinder 10?.^r>, nt l an a firr.t lower cylinder 1022, an upper cylinder head 1027, a lower cylinder . head 1026, at least three tie rods 1060, and associated fasteners 1061. The structure of press 1001 is also comprised of second upper cylinder 1023, second lower cylinder 1024, die cylinder 1056, and spacer ring 1020. Cylinders and spacer ring are mounted coaxially in a manner similar to that shown in Fig. 4. Spacer ring 1020 is coaxially adjacent to second lower ^'cylinder 1024, and die cylinder 1056, with one end being mounted against retraction end surface 1044 of second lower cylinder 1024, and the opposite end mounted against retraction end surface 1045 of die cylinder 1056.

Any number of cylinders may be mounted to provide the structure of a press, and other embodiments of the present invention may comprise more or fewer cylinders. Passing directly between upper cylinder head 1027 and lower cylinder head 1026 and connecting them so as to hold or tie the structure of press 901 together is at least one and preferably a plurality of tie rods 1060, and associated fasteners 1061. The tie rods 1060 and fasteners 1061 preferably have a cross sectional area for a given tie rod material and fastener material that is able to withstand a pressure approximately equal to the sum of the respective surface areas of the force receiving ends of the pistons within the cylinders multiplied by the respective motive force bding applied to each surface. These pressure values for a given tie rod material and fastener material and cross sections can be readily ascertainable . For safety reasons it is of course preferable to exceed this calculated pressure by at least a factor of 2 and preferably 4. This can be done by adding tie rods and fasteners, choosing stronger materials for the tie rods and fasteners, enlarging their cross sectional areas, or any combination of these. Die 1050 is affixed or formed in die holder 1059, which is affixed to an end of at least one die rod 1055, with the opposite end of die rod 1055 affixed to die piston 1054 which is able to move slidably within die cylinder 1056. Because the cylinders are coaxially mounted within the structure of press 1001, the punches are coaxial. Within first upper cylinder 1025 is piston 1041, with retraction face 1011 connected to first upper punch 1003, and with first upper ; punch face 1005 affixed to its opposite end. Within first lower cylinder 1022 is piston 1040 connected at retraction ,face -1010 to an end of first lower punch 1002, and with first lower punch face 1004 affixed to its opposite end. Within second upper cylinder 1023 is piston 1043 connected by its retraction face 1015 to one end of second upper punch 1007, with second upper punch face 1009 affixed to its opposite end. Within second lower cylinder 1024 is piston 1042 connected by its retraction face 1014 to one end of second lower punch 1006, with second upper punch face 1008 affixed to its opposite end. Affixed respectively to first upper piston 1041 and first lower piston 1040 are punch position indicators 1071 and 1072. Although shown mounted to pistons, one skilled in the art would realize that punch position indicators may also be attached to any portion of the press that moves. The distance each punch has moved is indicated by its respective tool position indicators, and is detected by sensors (not shown) associated with the tool position indicators, the signals from which are transmitted to an electronic controller such as electronic controller 372 shown in Fig. 1, preferably a microprocessor based controller. Using information from tool position indicators 1071 and 107-f and their associated sensors (not shown), and a predetermined , operating program, the controller controls the distance the punches move, thus and can determine whether the particulate material has been sufficiently compacted to form consolidated article 1053. Furthermore, as shown in Fig. 3, a single controller 4 can control the operation of a plurality of presses, and can also accept data input from various sensing devices affixed to a plurality of presses. Because cylinders that are adjacent to each other can be in contact with and attached to each other, and shafts can be nested within each other, other embodiments of the invention may have more or fewer cylinders, pistons and punches than are shown by the embodiments herein. In operation, particulate material 1052 is introduced into the die cavity 1051 while first and second lower punch faces 1004, 1008 form a floor in the die cavity 1051 to contain : particulate material 1052 within die cavity 1051 . Hydraulic pressure is applied to the force receiving faces 1012, 1013, _ι

-- 39 1016, ,and 1017 of pistons 1040, 1041, 1042, and 1043, causing punch faces 1004, 1005, 1008, and 1009 to move toward the particulate material that comprises the uncompacted powder 1052 contained in die cavity 1051. The punches enter the die 5 cavity, compacting and consolidating the particulate material therein. Upon sufficient compaction of the particulate material, first upper punch 1003 and second upper punch 1007 are withdrawn by application of hydraulic pressure on retraction faces 1011 and 1015. ^' Hydraulic pressure is then

10 applied to die piston force receiving face 1063, causing die 1050 and die holder 1059 to move toward second lower cylinder 1024. Because first and second lower punches 1002 and 1006 are maintained in position, the movement of die 1050 causes workpiece 1053 to emerge from the side of the die opposite to

15 that where the lower punches enter. Upon retrieval of the finished workpiece 1053, hydraulic pressure is applied to the retraction faces 1010 and 1014 of the lower pistons and the retraction face 1062 of the die piston 1054, causing the punches and die to move to the compaction procedure starting

?0 position.

Embodiments of the present invention may incorporate alternate arrangements of cylinders and pistons, such as the arrangement shown in Fig. 6, wherein the pistons and cylinders are arranged concentrically. Concentric piston press 1101 is

25 shown having a first upper cylinder 1133, a second upper cylinder 1134, and a third upper cylinder 1135 all having the same length relative to their common axis, arranged concentrically, commonly attached to the upper cylinder head 1110 a-t one end of the cylinders, and commonly attached to the

30 upper cylinder end 1131 at the opposite end of the cylinders. Likewise, a first lower cylinder 1136 and a second lower cylinder 1137 which have the same length relative to their

- - common axis, are arranged concentrically, with one end of the cylinders attached to the lower cylinder head 1120, and the

35 opposite end of the cylinders attached^' to the lower cylinder end 1132. The external surface 1138 of lower cylinder end 1132 is abutted coaxially to one end of cylinder spacer 1140, . and the opposite end of cylinder spacer 1140 is abutted coaxially to the external surface 1139 of upper cylinder end .1131». Thus the upper assembly of cylinders and pistons is oriented coaxially opposite the lower assembly of cylinders and pistons .

Referring now to Fig. 7, wherein is shown a detail of the arrangement of certain features of a concentric piston press. Annular piston assembly 1201 is comprised of annular piston 1212, affixed to at least one, and preferably a plurality of punch rods 1214, further affixed to punch holder 1216. Punch rods pass through cylinder end 1231, and are able to move ^• slidably through openings 1233 in cylinder end 1231.

Other arrangements and numbers of cylinders and pistons are practical and one with skill in the art would recognize are within the scope of the present invention. Although shown having a common axis that is vertical in relation to the horizon, the common axis of such an arrangement of cylinders may be oriented at any angle to the horizon.

Fig. 8 shows an alternate embodiment of the present invention as a closed mold press 1301, into which a fluid material, or a fluid compound, is introduced into an enclosed molding cavity and solidified therein, thereby retaining the contours on its surfaces that correlate to the surfaces of the enclosed

'l molding cavity, used in procedures such as those including die casting and plastic injection molding. A first closed mold portion 1302 and second closed mold portion 1303 are attached to the first upper punch face 1309 and the first lower punch face 1308 respectively. The figure shows the closed mold press 1301 in an open position, with the ejector pins 1311 partially ejecting work-piece 1353. In operation during a molding or casting procedure, hydraulic fluid (not shown) from an outside source (not shown) exerts pressure on force receiving face 1322 of piston 1320, and force receiving face 1333 of piston 1331, moving first closed mold portion 1302 and second closed mold portion 1303 toward each other. The mold portions are moved into contact with each other, so that first molding surface 1304 and second molding surface 1305 are engaged in such a way as to form an enclosed molding cavity with internal surface features correlating to the features of the work-piece, into which is introduced fluid material or compound capable of .solidification (not shown) that subsequently solidifies within the enclosed molding cavity thereby forming a 3 dimensional part. The closed mold portions remain in contact under pressure until the work-piece 1353 has solidified sufficiently ^'to be removed from the enclosed molding cavity. After the work-piece 1353 has been determined to be sufficiently solidified, hydraulic pressure is exerted on first lower piston retraction face 1324 and first upper piston retraction face 1335, causing first closed mold portion 1302 and second close mold portion 1303 to move away from each other, exposing work-piece 1353 and allowing it to be removed from the mold cavity. Hydraulic pressure is exerted on the force receiving face 1344 of the ejection piston assembly 1342, causing the ejection pins 1311 to force the work-piece 1353 away from the molding cavity surface. After the work-piece 1353 is removed, hydraulic pressure exerted on the retraction face 1346 of the ejection piston assembly 1342 retracts the ejection pins 1311. In this embodiment, additional pistons and cylinders can be added in a manner similar to that shown in Fig. 4, to provide injectors for introduction of the fluid material or compound into the molding cavity via channels similar to that shown in Fig. 3 through the pistons and associated features. An alternate embodiment of the present invention is that of a press used for forming materials including sheet metal in procedures that may include or combine, among others, bending, drawing, stretching, compressing, shearing, and cold welding, in procedures including stamping, coining, embossing, piercing, blanking, and dinking. Fig. 9 shows an embodiment of the; present invention as a single station stamping press. In press 1401, a punch 1409 is formed or affixed to an end of a first piston rod 1420 opposite from that to which is attached first piston 1431. A pressure plate 1446 is attached to annular piston 1440 via pressure plate rods 1448. Die 1411 is attached to base plate 1450 which forms the lower portion of the press frame 1452.

In operation, at least one portion of workpiece material 1453 is placed in position for the press to commence the operation. Other operations may have been performed on the material prior to its introduction to the pressing station. Hydraulic pressure from an outside source (not shown) is applied to annular piston force receiving face 1442, causing pressure plate 1446 to bear against workpiece material first surface 1454 of workpiece material 1453, and forcing workpiece second surface 1055 against the die 1411. Hydraulic pressure is then applied to first piston force receiving face 1433, causing punch 1409 to contact and move at least a portion of workpiece material 1453 into die cavity 1410 wherein contours and openings corresponding to those of punch 1409 and die 1410 are imparted to the portion in a cold forming operation.

Subsequent to the completion of the cold forming operation, hydraulic pressure is applied to the first piston retraction face 1435, causing punch 1409 to withdraw from the die cavity 1410, and hydraulic pressure is applied to the annular piston retraction face, causing the pressure plate 1446 to relieve pressure on the workpiece material, allowing the cold formed workpiece (not shown) to be withdrawn from the die cavity. In Fig. 10, an alternate embodiment of the present invention is shown as a press for hot or warm working material in procedures that include forging, thixoforming, and extrusion. Fig. 10 shows press 1501 with fiJrst die 1509 in the retracted position, and workpiece 1553 resting within second die cavity 1510 of second die 1511. First die 1509 is formed or affixed to an end of a first piston rod '1520 opposite from that to which is attached first piston 1531. Die 1511 is attached to base plate 1550 which forms the lower portion of the press frame 1552.

In operation, a quantity of heated material is deposited onto second die cavity 1510. While the material remains heated, hydraulic pressure is applied to first piston force receiving face 1533 of first piston 1530, causing first die 1509 to move toward second die 1511 and to come into contact with the heated material of the work piece. The movement of first die 1509 continues until sufficient flow of the material has occurred to cause the material to conform to the contours of first die cavity 1508 and second die cavity 1510 and to achieve material properties that include grain form and size, and material density. Subsequently, hydraulic pressure is applied to first piston retraction face 1535 to cause first ^ie 1509 to move away from second die 1511. The steps of moving the dies together and apart causing plastic flow of the heated material may occur once or may be repeated until the heated material conforms sufficiently to the die contours, or ^'the desired material properties have been achieved. To facilitate removal of work-piece 1553 from second die cavity 1510, hydraulic pressure is applied to second piston force receiving face 1542 of piston 1540, causing ejection rod 1546 to move toward first die 1509, and pushing work-piece 1553 out of second die cavity 1510. Ejection rod 1546 is retracted by ' applying hydraulic pressure to second piston retraction face 1544.

An alternate embodiment of the present invention is shown in Fig. 11 as a brake press for forming bends in material. Tool first part 1609 is attached to an end of a first piston rod 1620 opposite from that to which is attached first piston 1631. Tool second part 1610 is attached to base plate 1650 which forms the lower portion of press frame 1652. Tool position indicator 1637, is shown attached to piston 1631, and may also be attached to any portion of the press that moves with piston 1631.

In operation, material in sheet form to be bent is manipulated between tool first part 1609 and tool second part 1611. Hydraulic pressure is applied to piston force receiving face 1633, causing tool first part 1609 to move toward tool second part 1611. The angle and depth of the bend in the material are determined by the specific tool type chosen and the distance between the tool first and second parts. The distance is indicated bv the tool position indicator 1637, and < is detected by sensors (not shown) associated with the tool position indicator, the signals from which are transmitted to an electronic controller, preferably a microprocessor based controller (not shown) . Using information from the tool position indicator 1637 and its associated sensors (not shown) , and a predetermined operating -program, the controller controls the distance between tool parts thus controlling the angle and depth of the bend. Upon completion of the bend, tool first part 1609 is caused to move away from tool seconc part, 1611 by applying hydraulic pressure to piston retraction face 1635.

Fig. 12 shows an embodiment of the present invention as powder metallurgy press 1701, wherein particulate material 1355 to be formed into a finished article 1753 is delivered to the empty die 1709 via a channel 1712 through a first upper piston 1731 and first upper piston shaft 1730. The quantity of particulate material to be used measured by a weighing means 1757, and controlled by a valving means 1759 or other means of controlling the flow of particulate material. The quantity and flow of the particulate material are controlled by a controller (not shown) , preferably microprocessor based, and are defined by a predetermined program.

In another embodiment, the present invention is directed to a method for preventing part cracking upon ejection from a press. The method comprises providing a press for making work- pieces from particulate material. The press comprises at least one press piston operatively associated with a press punch. The press is so configured as to allow independent control and movement of each of the press pistons relative to each other press piston. Particulate material is provided to the die cavity of said press . The work-piece is made on the press by moving each of the press pistons toward the die until each press piston exerts pressure on the particulate material, thereby consolidating the particulate material into the work- piece. Before ejecting the work-piece from the press, the work-piece is held in place by moving each press piston until each press punch makes contact with the work-piece thereby providing substantially uniform support on the work-piece. This movement of the press piston is done to compensate for press punch deflection that occurs during and after pressing the part. When this occurs the result is that the press punches to not uniformly support the part and cracking can occur upon ejection. In the method each press piston can be moved toward the die until it reaches a fixed position to press the part or each press piston is moved toward the die until it reaches a fixed pressure to press the part. To eject the part each piston can be moved to a position whereby the work-piece is ejected from the die while substantially uniform support is maintained on the work-piece. Alternatively, the die can be moved relative to the work piece while maintaining substantially uniform support on the work piece.

In a further embodiment, the present invention is directed to a method for forming a work piece. The method comprises digitally controlling the introduction of a powder material into a die, digitally controlling the creation of a substantially uniform distribution of powder material in the die, pressing the powder material in the die from a first direction with a first set of work piece forming punches respectively operatively associated with a first set of at pistons by digitally controlling the direct application of a motive force to each of the first set of pistons. The pistons are thereby each slid within a first piston cylinder in a second direction towards the die. Each of the first piston cylinders are fixed relative to each other.

The method further comprises pressing the material in the die from the second direction opposite the first direction with a second set of work piece forming punches respectively operatively associated with a second set of pistons by digitally controlling the directj application of a motive force to each of the second set of pistons thereby sliding each within a second piston cylinder in the first direction towards the die. Each of the second piston cylinders is fixed relative to each other . In the present method the motive force is directly applied to each of the first pistons by digitally controlling the delivery of hydraulic fluid into each of the first piston cylinders. The step of pressing the material is carried out by digitally controlling the direct application of a uniform pressure to each of the first set of work piece forming punches .

In another embodiment, the method of forming a work piece comprises digitally controlling the introduction of a powder material into a die; digitally controlling the application of a first force directly to a first force receiving end of a first piston within a first piston cylinder to move the first piston within the first piston cylinder towards the die thereby pressing the material in the die with a first work piece forming end of the first piston extending out of the t t _— — .

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Claims

WHAT IS CLAIMED IS: l.A powder press manufacturing system comprising an independent power source; and at least one pressing module remotely associated ^'therewith, each said at least one pressing module comprised of at least one punch having an end for pressing a powder material to form a work piece, said at least one punch being operatively associated with a first end of a piston having a second force receiving end; at least one force applying • ' assembly configured to apply pressing force directly to the force receiving end; said at least one pressing module being operatively and reciprocally connected to and receiving power from said independent power source; and a die to receive and contain the powder, said die having an opening positioned to receive the end of the punch.

2. The manufacturing system according to claim 1, wherein the pressing module further comprises means for delivering powder into the die and creating a substantially uniform distribution of powder in the die.

3. The manufacturing system according to claim 1, comprising a plurality of pressing modules remotely associated with said independent power source.

4. The manufacturing system , according to claim 1, wherein said force applying assembly is a hydraulic assembly.

5. The manufacturing system according to claim 1, further comprising at least one pressing station remotely connected to said power source, wherein each of said at least one pressing module is removably attached respectively at one of said at least 'tine pressing station.

6. The manufacturing system according to claim 2, wherein said means for creating a substantially uniform distribution comprises a powder fluidizing apparatus.

7. The manufacturing system according to claim 1, further comprising at least one controller associated with each said at least one pressing module, said controller for controlling distribution of power from said independent power source to each of said at least one stations. ,

8. The manufacturing system according to claim 7, further comprising a computer interface associated with that controller.

9. The manufacturing system according to claim 7, wherein said controller controls the distribution of power from said independent power source by controlling hydraulic fluid delivery to and removal from the force applying assembly.

10. The manufacturing system according to claim 9, wherein said controller controls a rate at which each first ' piston moves towards the die so that at a point in time force/unit area² being applied to each said first surface of the work piece is the same.

11. The manufacturing system according to claim 9, wherein said controller controls a rate at which each first piston moves towards the die so that each first piston reaches each first surface of the work piece at the same point in time .

12. The manufacturing system of claim 1, wherein said punch being operatively associated with said first end of said at least one piston and is removable therefrom.

13. The manufacturing system of claim 1, wherein said punch being operatively associated with said first end of said at least one piston comprises a single monolithic part.

14. The manufacturing system of claim 1, further comprising at least one second punch extending a second direction opposite that of said at least one first punch and towards said die.

15. The manufacturing system of claim 14, wherein said at least one second punch is fixed.

16. The manufacturing system of claim 14, wherein said at least one second punch is operatively associated with a first end of at least one second piston having a second force receiving end.

17. The manufacturing system of claim 1, wherein said first piston moves toward and into said die until it moves a predetermined distance n the cylinder.

18. The manufacturing system of claim 1, wherein said first piston moves toward said die until a predetermined force is being applied to a first surface of the work piece.

19. The manufacturing system according to claim 1, wherein said first piston moves toward and into said die until a mechanical stop is reached.

20. The manufacturing system according to claim 1, further comprising a controller for controlling a rate at which each said first piston moves so that at a point in time force/unit area² being applied to a first surface of the work piece is the same.

21. The manufacturing system according to claim 1, further comprising a controller for controlling a rate at which each first piston moves so that each first piston reaches each of a first surface of the work piece at the same point in time .

22. A modular manufacturing system comprising an independent power source; and at least one manufacturing module remotely associated therewith, each said at least one manufacturing module comprised of at least one tool having an end for working a material to form a work piece, said at least one tool being operatively associated with a first end of a piston having a second force receiving end; at l^ast one force applying assembly configured to apply pressing force directly to the force receiving end; said at least one manufacturing module being operatively and reciprocally connected to and receiving power from said independent power source; and a die to receive and contain the material, said die to engage the end of the punch .

23. The manufacturing system according to claim 22, wherein the manufacturing module further comprises means for delivering the material to the.

24. The manufacturing system according to claim 22, comprising a plurality of manufacturing modules remotely associated with said independent power source.

25. The manufacturing system according to claim 22, wherein said force applying assembly is a hydraulic assembly.

26. The manufacturing system according to claim 22, further comprising at least one manufacturing station remotely_^ connected to said power source, wherein each of said at least one manufacturing module is removably attached respectively at one of said at least one manufacturing station.

27. The manufacturing system according to claim 22, further comprising at least one controller associated with ^'each said at least one manufacturing module, said controller for controlling distribution of power from said independent power source to each of said at least one stations.

28. The manufacturing system according to claim 22, further comprising a computer interface associated with that controller.

29. The manufacturing system according to claim 22, wherein said controller controls the distribution of power from said independent power source by controlling hydraulic fluid delivery to and removal from the force applying assembly.

30. The manufacturing system according to claim 22, wherein said tool is configured as a stamp.

31. The manufacturing system according to claim 22, wherein said tool is configured as a forging press.

32. The manufacturing system according to claim 22, wherein said tool iε configured as a closed mold

1 for casting fluid material.

33. The modular manufacturing assembly according to claim 22, wherein said tool is configured as a closed die for receiving casting material.

34. A press for forming a work piece, comprising: a computer controller; a computer interface operatively connected to said controller, at least one tool to form a work piece, said at least one tool being operatively associated with a force receiving piston; at least one force applying assembly configured to apply pressing force directly to the force receiving piston, wherei-n said computer controller controls said at least one force applying assembly; and a die to receive and contain material from which the work is formed. ,

35. A method for forming a work piece, comprising the steps of: digitally controlling the introduction of a powder material into a die; digitally controlling the creation of a substantially uniform distribution of powder material in the die; pressing the powder material in the die from a first direction with a first set of at least one work piece forming punches respectively operatively associated with a first set of at least one pistons by digitally controlling the direct application of a motive force to each of the first set of at least one pistons thereby sliding each within a first piston cylinder in a second direction towards the die, each of said first piston cylinder being fixed relative to each other.

36. The method according to claim 35, further comprising pressing the material in the die from the second direction opposite the first direction with a second set of at least one work piece forming punches respectively operatively associated with a second set of at least one pistons by digitally controlling the direct application of a motive force to each of the second set of at least one pistons thereby sliding each within a second piston cylinder in the first direction towards the die, each of said second piston cylinders being fixed relative to each other.

37. The method according to claim 35, wherein the motive force is directly applied to each of said first pistons by digitally controlling the delivery of hydraulic fluid into each of the first piston cylinders. ^■t

38. The method according to claim 35, wherein the step of pressing the material is carried out by digitally controlling the direct application of a uniform pressure to each of said first set of at least one work piece forming punches .

39. A method of forming a work piece, comprising the steps of: digitally controlling the introduction of a powder material into a die; ■digitally controlling the application of a first force directly to a first force receiving end of a first piston within a first piston cylinder to move said first piston within said first piston cylinder towards the die thereby pressing the material in the die with a first work piece forming end of the first piston extending out of the first piston cylinder in a first direction.

40. The method according to claim 39, further comprising the digital control of the application of a second force directly to a second force receiving end of a second piston within a second piston cylinder and thereby pressing the material in the die with a second work piece forming end of the second piston extending out of the second piston cylinder in a second direction.

41. The method according to claim 39, wherein the first direction is the same as the second direction.

42. The method according to claim 39, wherein the first direction is opposite the second direction.

43. The method according to claim 39, wherein the first piston cylinder and the second piston cylinder are hydraulic cylinders and the first piston ajd the second piston are hydraulically operated.

44. The method according to claim 38, further comprising the step of digitally controlling the distance for the first piston to move within the first piston cylinder based on the work piece being formed.

45. The method according to claim 44, further comprising the step of digitally controlling a distance for the s.econd piston to move within the second piston cylinder based on

46. A modular manuf cturing assembly comprising an independent power source; and at least one manufacturing station remotely associated therewith, each said at least one manufacturing station receiving power from said independent' power source and comprising a manufacturing module removeabl y and operatively connected thereto, each manufacturing module comprised of at least one tool to form a work piece, said at least one tool being operatively associated with a first end of a piston , having a second force receiving end; at least one force applying assembly configured to apply force directly to the second force receiving end.

47. The modular manufacturing assembly according to claim 46, wherein said tool is configured as a stamp.

48. The modular manufacturing assembly according to claim 111, wherein said tool is configured as a forging press.

49. The modular manufacturing assembly according to claim 46, wherein said tool is configured as a closed mold for casting fluid material.

50. The modular manufacturing assembly according to claim 46, wherein said tool is configured as a closed die for receiving casting material.

51. The modular manufacturing assembly according to claim 46, wherein said tool is configured as a closed die into which plastic is injected.

52. The modular manufacturing assembly according to claim 111, wherein said tool is configured as a brake press.

53. A method for preventing part cracking upon ejection from a press comprising the steps of: providing a press for making work-pieces from particulate material, said press comprising at least one press piston operatively associated with a press punch, said press being so configured as to allow independent control and movement of each said at least one press piston relative to each other said at least one press piston, providing particulate material in a die cavity of said press, making a work-piece on said press by moving each said at least one press piston toward the die until each said at least one press piston exerts pressure on said particulate material, thereby consolidating the particulate material into the work- piece, before ejecting the work-piece from said press, holding the work-piece in place by moving each said at least one press piston until each press punch makes contact with the work- piece thereby providing substantially uniform support on the work-piece. ,

54. The method according to claim 53, wherein each said at least one press piston is moved toward the die until it reaches a fixed position.

55. The method according to claim 53, wherein each said at least one press piston is moved toward the die until it reaches a fixed pressure.

56. The method according to claim 53, further comprising the step of moving each said at least one piston to a position whereby the work-piece is ejected from the die while maintaining substantially uniform support on the work-piece.

57. The method according to claim 53, further comprising the step of moving moving the die relative to the work piece while maintaining substantially uniform support on the workpiece .