Abstract: A powder molding press includes a die plate provided with a die having a die hole, a punch device to be inserted into the die hole and a hydraulic cylinder device attached to the punch device for driving the same, the hydraulic cylinder device being arranged coaxially with the punch device. A movable punch plate may be disposed on one side of the die plate in parallel thereto with a predetermined space and a punch adapter for securing the punch device to the punch plate may be also disposed. The punch device includes a plurality of punches disposed axially in series.

Abstract: In a hydraulic circuit a positive-displacement pump has a flywheel. An actuation motor is attached to the positive displacement pump. The pump is capable of directing liquid flow either towards the tank or towards a hydraulic cylinder. The control of flow direction is determined by a first valve which is connected on the output side of the pump in order to discharge the flow of the positive displacement pump either to the tank or to the cylinder. The opening speed of the first valve is controlled. A bistable valve feeds the pilot line of the first valve. A distribution valve, connected with the output side of the pump feeds two pressure lines.

Abstract: An apparatus and method is disclosed for an improved press for pressing a compressible material such as a deformable plastic material with a fluid under pressure from a fluid pressure source. The press incorporates a press cylinder having a press cylinder bore for removably receiving a sleeve defining a sleeve bore. The sleeve bore is adapted to receive the compressible material between a first and a second forming tool. The fluid from the pressure source is applied to the first and second forming tools to press the compressible material therebetween.

Abstract: A device for forming a two-tiered external helical gear, having upper and lower parts having pitch circles of different diameters, includes a die, an upper punch and a lower punch which are rotatable relative to one another, and a core. The die is formed on the inner periphery with helical teeth in two tiers. The upper and lower teeth have the same twisting direction and lead and have pitch circles of diameters corresponding to the diameters of the pitch circles of the upper and lower parts of the gear. The upper punch is formed on the outer periphery with helical teeth adapted to mesh with the first tier of helical teeth on the inner periphery of the die. The lower punch is formed on the outer periphery thereof with helical teeth adapted to mesh with the second tier of helical teeth on the inner periphery of the die. There is also provided a similar device for forming a two-tiered internal helical gear.

Abstract: A brick press easily exchanges a mold as well as a material in a short time in the same way as a mold exchange in a die floating type press in which a press molding is performed only by an upper plunger of the press body with the mold holder being moved vertically. The brick press includes a plurality of transfer trucks provided with a device for removably mounting a mold and a device for supplying raw material. A pin positions the transfer truck to the brick press. In another embodiment, the brick press includes a plurality of transfer trucks. Each transfer truck is provided with the device for supplying raw material, a device for moving the raw material supply device, a device for lifting and lowering the raw material supply device, and a pin for positioning the transfer truck to the mold holder.

Abstract: An apparatus for the production of pellets of metal powder, more particularly pellets of highly active metal powder, for example Raney catalysts, has a press with a filling shoe and a pellet discharge shoot. A wet processing environment is established and thus no inert gas atmosphere is required to avoid oxidation of the metal powder.

Abstract: A machine for producing lollipops 3 having a rotatable die ring 6 with radial press rooms 11 into which cut sugar pieces 1 are fed from inside the die ring and from which the completed lollipops 3 are discharged outwardly, with assistance of centrifugal force. Pivotal flaps 16 are provided to prevent escape of the cut sugar pieces from the cavities of movable shear blades 7 after the cut sugar pieces have been successively fed into the cavities.

Abstract: A pressure molding machine for molding various types of stepped articles having, a nest of ram adapters receiving thereon pressure rams and a common base support having cylindrical walls positioned coaxially. The end faces of the walls are at the same level for receiving thereon base ends of the ram adapters, and a nest of movable frames each operated by a pressure cylinder. The movable frames move along guide channels provided in the cylindrical walls of the common base support for operating the ram adapters. Total length and total weight of the machine can be minimized, a die-set is easy for manufacturing, mounting and exchanging, and costs for the equipment can also be minimized.

Abstract: There is disclosed a tooling (punch) face for pressing chemical tablets which essentially comprises a central flat area of about 75% of the outer diameter of the tool surrounded by a peripheral radial area or arcuate area which comprises about 25% of the outer diameter of the tool. The tool face is such that it enables a conformed tablet to be fabricated utilizing the tool surface whereby one can employ powdered chemical compositions and virtually eliminate excipients.

Abstract: A ceramic chip-resistant chamfered integrated circuit package and an apparatus for and method of manufacture thereof. The exposed-surface edge of each short end of a ceramic package component (base and/or cap) are made with an integral chamfer at an angle of from about 20.degree. to about 85.degree. relative to the plane of the opposing inner surface of the component. The height H of the chamfer is from about 20% to about 67% of the thickness T of the ceramic package component. In particular, the preferred angle of the chamfer is from about 50.degree. to about 70.degree., with a preferred height H of about 30% to about 50% of the thickness T. The integral chamfer of each ceramic package component is made by means of an inventive die-press apparatus for inverted formation of the ceramic package component. The inventive method forms the chamfers without causing localized compaction of the ceramic powder starting material.

Abstract: A hydraulic device is described which operates with an open hydraulic circuit. The device includes a positive-displacement pump for driving hydraulic fluid. An actuation motor having a flywheel is attached to the positive-displacement pump. A tank for hydraulic liquid is connected via a delivery line to the pump. The pump capable of directing hydraulic fluid flow either towards the tank or towards a hydraulic actuation means. The control of flow direction is determined by a first directional control valve means which is connected on the output side of the pump in order to discharge the flow of the positive displacement pump either to the tank or to the hydraulic actuation means. A method for pressing bodies to be processed is also described.

Abstract: In a press forming apparatus for forming spiral parts, a plurality of first connecting rods are mounted on a lower end of a divided core divided from a die in shifting relation to each other in a winding direction of vortex. The plurality of first connecting rods are supported by a vertically movable core plate, while a plurality of second connecting rods are mounted on a lower end of a lower punch in shifting in position relation to each other. The second connecting rods extend respectively through bores in the core plate, and are supported by a lower punch plate movable vertically and arranged below the core plate. Further, the first and second connecting rods extend through a stationary block. The stationary block is arranged between the die and the core plate, for restricting downward movement of the lower punch and the divided core.

Abstract: A rotary pelletizing machine has a rotatable matrix disc, a plurality of vertically adjustable pressing rollers which control position of the upper and lower plungers, a drive for a height adjustment of the rollers, a housing accommodating the drive, and a bearing block supporting the pressing roller and releasably connected with the housing.

Abstract: A press is provided for simultaneously pressing and piercing an object. The piercing means moves from a sheathed to unsheathed position in response to compressive pressure. The piercing means are normally biased in the sheathed position by a bias means. Methods and apparatus for piercing an object are disclosed. The press can be used to produce a pierced dispensing device having a compression coating by (a) charging to a die mold a quantity of powder to be compressed; (b) delivering to the die mold an unpierced dispensing device core; (c) charging to the die mold an additional quantity of powder to be compressed; and (d) substantially simultaneously (i) compressing the elements within the die mold to produce a compression coating, and (ii) piercing the compression coating. The compression coating can comprise, for example, a loading dose or a semipermeable membrane.

Abstract: Anisotropic rare-earth permanent magnets characterized in that an aggregate of a plurality of blocks, to each of which anisotropy is imparted, is formed using powders of magnetic material containing rare-earth elements, and the adjoining blocks are powder-metallurgically bonded together under pressure into one piece; a method of making anisotropic rare-earth permanent magnets by molding anisotropic blocks by magnetic-field molding, arranging, aggregating and sealing a plurality of blocks in a bag, and cold hydrostatic pressing the aggregate of blocks in the absence of magnetic field; and a suitable metal mold for magnetic-field molding anisotropic permanent magnets of a relatively large size.

Abstract: The present invention relates to a method and apparatus for the manufacture of finished parts by the sintering of compacts which are formed as composite moldings of a pulverulent base material and at least one other pulverulent material, particularly different metal powders. The compacts are produced in the manner that at least one of the powder materials is introduced in pourable condition directly alongside of an already pre-compacted part of the compact into the mold which has a shell-shaped matrix and the powder materials are subjected together to final compacting by plug forces acting from on top and on bottom to the size desired for the sintering.

Abstract: A pressure molding device having a powder supporting flat face formed by the end face of a pressure ram or a pressure-submissive block and a reciprocating vertical sleeve. The layer of powder formed on the flat face and having a uniform density is cut with the vertical sleeve's end for molding. A molded body has a uniform density in all portions and deformation does not occur in the course of sintering for producing semiconducting or insulating base boards.

Abstract: An apparatus for shaping, by compacting, carbonaceous blocks formed by a carbonaceous paste based on a carbonaceous aggregate such as coke, anthracite or graphite, and an organic cokable binder such as tar and optional additives. The carbonaceous paste is introduced into a mould in which some of the walls are displaceable with respect to their initial position and there are successively applied to said paste at least one stress .sigma.n along an axis An, then at least one stress .sigma.n+1 along an axis An+1 which is not coincident with the axis An, then at least one stress .sigma.n+2 along an axis An+2 which is not coincident with the axis An+1, and so forth, repetitively, each stress .sigma.(i) being applied after at least partial suppression of the stress .sigma.(i-1). Use of the apparatus substantially enhances compactness of the carbonaceous blocks.

Abstract: Molding apparatus, particularly for mounting specimens for microstructural analysis. A ramhead pressurizes a molding chamber, with the pressure, temperature and time of the cycle being set into the system from a control panel and proceeding automatically. The ramhead is advanced through a hydraulic system. A spring is provided for mounting the tubular molding chamber to permit the molding chamber to spontaneously align with the advancing ramhead. A wrench member is provided as an integral part of the apparatus to rotationally lock the handle to the molding chamber, to permit rotation of the molding chamber through the handle for removal thereof when desired.

Abstract: Apparatus and method for molding a plurality of articles having various masses and shapes wherein a parison mass is injected at constant back pressure through a time controlled valve from a supply of molten molding material at predetermined temperature and pressure. The articles are compression molded at predetermined pressures in accordance with their shapes or masses. The variable compression pressures are provided in one embodiment by similar actuators which are unequally excited; and in another embodiment an actuator is coupled to a mold cavity by a machine having a variable mechanical advantage. The actuators are pivotally mounted. A series of lenses including negative powers is particularly contemplated.

Abstract: A press for producing dimensionally stable moldings from powdered materials is described whereby a press frame and a press platen are provided in a press body and are linked together in movement by means of a drive and form a main press plunger. A hydraulic press part with at least two additional press axes is mounted in front of the main press plunger between the press frame and press platen. The second hydraulic press axis of hydraulic press part is actuated and controlled by its first axis through a hydraulic coupling device that has a variable transmission ratio, while the first axis of the hydraulic press part is in turn actuated by the press frame of the main press plunger. The movement ratios of the second press axis of the hydraulic press part can then be varied relative to the main press axis.

Abstract: A device for the controlled release of a substance having useful activity into a fluid medium at a substantially constant rate, said substance contained in a shape which is substantially that of a truncated cone by means of an impermeable wall or coating on the base and side (but not the top) of said truncated cone. Apparatus useful in manufacture when said device is a tablet for administration to a mammal.

Abstract: Apparatus for forming graphite into packing rings utilizes a press to compress the graphite within a movable die. The graphite is supplied to the press by the combination of a turntable-type feeder and a tubular feeder which places increments of the graphite in dies carried by the turntable. The punch has a retractable pin which cooperates with a lower core pin to maintain the interior diameter of the rings as they are formed. The press and turntable are connected for synchronous operation.

Abstract: An optic for an intraocular lens with finished, molded radii on the anterior and posterior edges of the peripheral surface of the optic. The optic has a thin central optical zone and a surrounding annular ring having sufficient material to support haptics. The ring is thicker than the optical zone and, thus, recesses the posterior surface of the optical zone to provide a capsulotomy space. The present novel optic is produced by novel molding pins which are shaped to provide the finished molded radii on the edges of the optic so that the optic requires little or no post-molding finishing or polishing other than the degating and deflashing.

Abstract: A cap heat-sealing apparatus for containers comprises a stationary pressing member (18), and movable pressing members (19) arranged around the stationary pressing member (18) and identical in number to the number of corners of a container opening fitting portion (8) of a polygonal cap (5) formed at its periphery for heat sealing. The stationary pressing member (18) has an outer periphery shaped in conformity with the shape of the inner periphery of the fitting portion (8). Each of the movable pressing members (19) is movable toward or away from the stationary pressing member (18) in a horizontal direction through the center of the stationary pressing member (18) and the corner thereof opposed to the movable pressing member (19).

Abstract: A method of and apparatus for pelletizing a radioactive waste powder is disclosed. The apparatus includes a pelletizing section, and a pelletizing die which has one end facing a powder receiving cavity formed in the pelletizing section and the other end exposed to the atmosphere, and a through bore is so formed in the die as to pass from the one end to the other end. A first pelletizing rod can be inserted into and pulled out of the through bore from the one end of the die through the cavity, and a second pelletizing rod can be inserted into a pulled out of the through bore from the other end of the die. The first and second rods are arranged such that, when the second rod takes a predetermined position in the through bore, the first rod is inserted through the receiving cavity into the through bore, thereby enabling the pelletizing operation of the powder within the through bore.

Abstract: A molding machine for making bricks, etc. having a mold open on both ends and opposed plungers for cooperation with the mold, the mold and plungers being removable and replaceable as a set.

Abstract: A tablet having the shape of a gelatine capsule avoids the swallowing and digestion drawbacks of said capsules and consists of a blend of one or more excipients and granules of one or more active substances, said blend being compressed along the longitudinal direction, i.e. at both heads or ogives, so as not to damage integrity of granules, in a suitable molding device provided with at least an upper die and a lower die. The invention relates also to such a device as well as the process of obtaining said tablet.

Abstract: Apparatus and method for compensating uneven gravity filling with powder material of a die cavity formed on the top of a punch reciprocable in a bore in a die plate, the punch having an end face normally parallel to the surface of the die plate. The punch is mounted on an adjustable support member split into portions having each an end face disposed parallel to the end face of the other portion. The two portions have a common surface of junction disposed in a plane at an angle to the parallel end faces. The two portions are rotated together to orient the surface of junction in the direction of inclination of the punch, and the two portions are independently rotated the same amount in opposite directions as a function of the desired angle of inclination of the punch.

Abstract: As in the conventional manner for molding an optical component, a molding cavity is used in combination with a relief chamber with which the molding cavity can selectively communicate. There is no communication between the relief chamber and the molding cavity while the latter is filled. The molding cavity is then placed in communication with the relief chamber. Subsequently, relative displacement of the relief chamber and the molding cavity parallel to the axis of the combination interrupts such communication. The optical component thus molded may be of any kind, such as an optical lens, specifically an ophthalmic lens.

Abstract: In the production of molded articles from a pourable substance, such as a porcelain substance, a hollow mold space is formed between a pair of horizontally displaceable compression mold parts. In the closed molding position, the mold parts are is spaced relation and form an annular gap laterally enclosing the mold space. An annular member forms a closure for the gap. The pourable substance is introduced into a passage through the closure member and through the gap into the mold space. A vacuum system is provided in the closure member in communication with the mold space during the step of filling the pourable substance into the mold space.

Abstract: In an arrangement for and a method of producing shaped parts of a non-swellable mixture of fibers and heat-hardenable resin, a pressing mass divider is introduced into lower pressing tool during filling of the mixture.

Abstract: An apparatus and method for molding polycarbonate lenses is disclosed in which the lenses are formed in a single injection molding operation. Polycarbonate is injected into a cavity between two movable dies which are forced apart by the injected polycarbonate. These dies are then urged together forcing a portion of the injected polycarbonate back through the same port through which the polycarbonate was injected. The finished lens does not have the knit line normally associated with injection molded lenses.

Abstract: A brick-forming vacuum press is provided with a die and top and bottom plungers which are disposed along the same vertical central axis as the die. Spaces which extend from the die and surround the top and bottom plungers are enclosed by chambers formed of sealing cylinders, flexible bowl-like skirts and sealing flanges. A horizontal table is provdided on the die to support a mix-filling charger and a compact-discharging pickup device. A wiper is carried by the pickup device to clean the table when the pickup device is shifted away from the vertical central axis of the press. Controls are provided to automate the filling of the die, press-forming and discharging of the resultant compact.

Abstract: A transmission member of the kind comprising a floating core free to move in all directions within a casing, the floating core comprising at least two arms disposed at an angle to one another, one for supporting a driven member, the other for actuation by a driving member, and the casing comprising an internal housing with a configuration which duplicates that of the floating core. Between the floating core and the walls of the internal housing is disposed there is disposed an insulating layer of a solid elastic material. Use of the transmission member is directed, in particular, to ultrasonic assistance in compacting or drawing.

Abstract: In a press operable for movements of proof plate exchangeably mounted on an end of a press die into and out of a mold, and wherein the proof plate normally does not exceed a position wherein its topmost portion is at most flush with a topmost portion of the mold during the movements, the improvement includes a drive device independent of the movements for moving the proof plate beyond the topmost portion of the mold, so that the proof plate projects through the mold, and is thereby freely accessible for the purpose of being replaced.

Abstract: A punching tool for use in a tablet making machine includes a body portion having at least one bore extending from an end of the holder a preselected distance into the holder. The bore is internally threaded a preselected depth. An interchangeable punch is threaded into the punch holder bore and extends a selected length from the holder. The end of the punch has an externally threaded portion and a cylindrical portion. The cylindrical portion is positioned between the threaded portion and the portion of the punch that extends outwardly from the holder. The cylindrical portion has a diameter that permits it to move freely without interference into and out of the internally threaded bore. The bore has an enlarged thread configuration provided with cylindrical bearing surfaces between threads. The punch threaded portion has a thread configuration corresponding to the configuration of the threaded bore to permit rapid engagement and disengagement of the punch in the bore.

Abstract: A press designed for producing true-to-size workpieces from powder material has upper and lower platens, a base plate, a die support plate and a lower stamp, which is moved hydraulically in translation in relation to the base plate and the die plate. The die plate and the base plate are parts of a frame structure using pull-rods and having the die plate and a lower joining plate as parts thereof. The frame structure is joined with the top platen of the press by way of a connection piece, which may be moved in translation in relation to the frame structure in the direction of pressing, whereas the lower platen of the press is joined up with the lower joining plate. To get an even density in the pressed workpieces and to make possible the use of modern electronic control systems the lower stamp of the press is made up of at least two lower stamp parts which are supported on machine parts.

Abstract: Blocks with a casing composed of upper and lower parts are produced by inserting the upper and lower parts in an inserting device above and below pushing elements between upper and lower pressing dies of a press, displacing by the pushing elements the lower part in a chamber of a mold towards the lower pressing die and the upper part towards the upper pressing die with self-releasable holding on the latter, withdrawing the inserting device from a pressing region between the upper and lower pressing dies, and cyclically repeating these steps in synchronism with a working stroke of the press.

Abstract: A hydraulic press is provided including a frame having a pair of spaced-apart vertical side members and a crown, and a mold box rigidly supported between the vertical side members and including a vertical mold cavity. A lower plunger assembly is positioned below the mold box and includes at least one plunger adapted to extend upwardly into the mold cavity, and an ejection cylinder assembly is provided for causing selective vertical movement of the lower plunger assembly. An upper plunger assembly is positioned above the mold box and includes an upper plunger adapted to extend downwardly into the mold cavity, and a hydraulic ram is provided for supporting the upper plunger assembly for vertical movement with respect to said mold box and with respect to said lower plunger assembly. The hydraulic ram includes a cylinder fixed to the lower plunger assembly and a ram housed in the cylinder and adapted to selectively drive the upper plunger assembly downwardly.

Abstract: Disclosed is a pressure cylinder apparatus having a cylinder and a slidable member such as a ram or piston which is slidable back and forth in response to charging and discharging of fluid into and out of the cylinder, wherein that the said slidable member has a polygonal cross-sectional shape and that the said stopper assembly having an aperture of a polygonal shape corresponding to the polygonal cross-section of the slidable member is provided in the plane perpendicular to the direction of movement of the slidable member so that the stopper assembly prevents or limits the undesirable rotation of the slidable member during outward movement of the slidable member, and disclosed also is a hydraulic press incorporating the pressure cylinder apparatus stated above, and the end surface of the said slidable member is shaped and sized to conform with the press mold part to which the end surface portion is connected.

Abstract: In a multi-motion powder compacting press for making a useful article from powdered metal, ceramic or other particulate material, an upper assembly comprising a frame, a driven bull gear, a crankshaft having a cam and a pitman for reciprocally operating one or more upper punches into a die cavity, an improved compacting and ejection assembly depending from the frame and having a pair of inner and outer lower rams, adjustably supported by a pair of vertically spaced pressure plates, and adjustable ejection plates for upwardly ejecting a pressed article from the die cavity.

Abstract: A hydraulic press for refractory material including a mold box rigidly supported by a press frame. A lower plunger assembly positioned below the mold box and includes a lower crosshead and at least one plunger adapted to extend upwardly into a vertical mold cavity in the mold box. An ejection cylinder assembly supported by the press crown is provided for causing selective vertical movement of the lower crosshead. An upper plunger assembly is positioned above the mold box and includes an upper crosshead and at least one upper plunger supported by the crosshead and adapted to extend downwardly into the mold cavity. A hydraulic cylinder is provided for supporting the upper crosshead for vertical movement with respect to the mold box and the lower crosshead. The hydraulic cylinder is fixedly connected to the lower crosshead, and a ram is housed in the cylinder and adapted to selectively drive the upper crosshead downwardly.

Abstract: In a die, punch and core rod assembly for a powder compacting press wherein the core rod or rods remain stationary while the punch or punches are reciprocable relative to the die, the invention provides individual longitudinal position adjustment for the core rods by fitting the end of the core rods in a threaded member such as a set screw threading in a threaded bore in a core rod support member. The core rod support member is in the form of a pair of plates one defining a core rod support plate and the other a retainer plate, sandwiching a plastic locking plate. The core rods are immobilized in their adjusted position by the plastic locking plate, sandwiched between the core rod support plate and the retainer plate, being provided with a threaded bore aligned with the threaded bore in the support plate and having a slight screwthread mismatch with the threaded bore in the support plate.

Abstract: A brick forming machine comprising an upper vacuum room mounted on a frame lifting up and down and enclosing an upper piston therein, an upper sealing ring mounted on the frame for sealing contact to an upper face of a mold, a lower vacuum room mounted on a truck and encircling a lower piston and giving airtight contact to a lower face of the mold, a lower sealing ring mounted detachably on an upper face of a lower half of a main body, spaces between the upper vacuum room and the upper sealing ring and also between the lower vacuum room and the lower sealing ring being respectively connected to upper and lower skirts in airtightening condition, and vacuum pressing forming operation is performed by extracting air in the spaces through an extracting pipe.

Abstract: In an anvil assembly for powder-compacting press wherein an article is compacted of powder material against the face of the anvil clamped in position over a die cavity filled with powdered material, a reciprocable punch being disposed at the bottom of the die cavity for compacting the powdered material against the anvil face, the anvil is provided with a movable face portion which, during compaction of the powder material, is displaced away from the die cavity, compressing an elastomeric return spring.

Abstract: A press for compressing pulverulent materials into both concave and convex pieces includes a press frame, a die carying plate, upper and lower punches, holders for carrying the punches and control devices for controlling the displacement of the upper and lower punches. The press comprises also a first piston-cylinder device for controlling the displacement of the die carrying plate, a second piston-cylinder device fastened to the frame and supporting the die carrying plate, levers arranged above the die carrying plate and having one end pivoted to the frame and sliders slidable on the opposite ends are provided in the press. The first piston cylinder device acts on the other ends of the levers to exert thereon a pressure depending on the distance of the sliders from the other ends of the levers.

Abstract: A die, punch and core rod assembly for a powder compacting press wherein the core rod or rods remain stationary while the punch or punches are reciprocable relative to the die. The invention provides individual longitudinal position adjustment for the core rods by fitting the end of the core rods in a threaded member such as a set screw threading in a bore in the core rod support plate. Alternatively, the invention provides for position adjustment of the core rod support plate by supporting the support plate below the die plate by spacer sleeves having a threaded peripheral portion threading in a bore in the core rod support plate. By combining an adjustable core rod support plate with individually adjustable core rods, the core rods can be adjusted longitudinally relative to each other, and in unison by way of the position adjustment provided for their support plate.

Abstract: A die for compacting powder by dynamic compaction. The die is intended for compaction pressures substantially above 1 GPa. The die is made of a mixture of a plastic material and a metal powder. The die has the same density before compaction as the powder to be compacted. Furthermore, the die undergoes the same increase in density during compaction as the powder being compacted. The die is cheap relative to a steel die and can, thus, be made for single use. The range of geometries possible to compact is greatly extended.

Abstract: A powder press has a fixed plate secured to a frame and having mounted thereon stops which are adjustably movable up and down. The stops are in abutting contact with rotatable stop rods which are threadedly mounted to an intermediate plate carrying a floating punch and which receives downward thrust during the process of compaction. The stop rods are locked against rotation by locking members during compaction and released therefrom upon descent of ejector rods which press down the intermediate plate and a die plate at the time of the ejection of the compact. The released stop rods rotate about their own axes to permit the descent of the intermediate plate. The abutting stop rods and stops make no large space requirement, and their rigidity is high.