Abstract: Molten metal is introduced into the cavity by a combined gravity feed and centrifugal force feed using a rotating turntable under electrical or electronic control. The centrifugal force is controlled to be substantially constant until the metal has solidified. This is accomplished by controlling the ramp-up acceleration of the turntable where rotational velocity is a time-dependent function of rotational radius and molten metal mass and taking into account the flow rate and cooling rate of the liquid metal. The process reduces waste and the attendant energy consumption associated with the quantity of metal required to be melted for the initial pour and associated with reprocessing and reusing the waste component.
Abstract: An apparatus for centrifugal casting under vacuum includes a rotor having a shaft extending in an essentially vertical direction and being rotatable around an axis defined by the shaft. The rotor has at least one mold, at least one crucible, and a gas-tight housing in which the mold and the crucible are accommodated. The apparatus also includes a vacuum source to create a vacuum in the housing, a heating device that melts a metal, a drive device that drives the shaft in order to rotate the rotor, and an auxiliary acceleration device configured to generate a force to further rotate the rotor to overcome a moment of inertia of the rotor. The auxiliary acceleration device includes a jet propulsion and/or at least one pushing actuator accelerating the resting rotor.
Abstract: A method of producing a precision centrifugal casting includes: a) providing a centrifugal casting device having a rotor rotatable around an axis, at least one crucible accommodated in the rotor, and at least one mold associated with the crucible and disposed at a first radial distance from the axis, b) creating a metal melt within the crucible, c) rotating the rotor thereby forcing the melt using centrifugal forces from the crucible into the mold, d) exerting a pressure on the melt forced into the mold until the temperature of the solidifying melt has reached a predetermined cooling-temperature in a range of 1300° to 800° C., wherein the pressure corresponds to the centrifugal force acting on the melt just when the mold is completely filled, times a factor of 1.0 to 5.0, and e) relieving the pressure when the temperature of the solidifying melt is lower than the predetermined cooling-temperature.
Abstract: A turbine blade having a leading edge portion and a flowing-off edge portion is formed using the following steps: providing a centrifugal casting device having a rotor and at least one crucible being accommodated in the rotor; providing a mold having an extended cavity for forming the turbine blade; arranging the mold so that an inlet opening of the mold is arranged with an outlet opening of the crucible, and further arranging the mold so that a mold leading edge is directed in a direction against the rotational direction of the rotor; forcing a metal melt by means of centrifugal forces from the crucible into the mold; exerting a pressure on the melt being forced into the mold until the temperature of the solidifying melt has reached a predetermined cooling-temperature; and relieving the pressure when the temperature of the solidifying melt is below the predetermined cooling-temperature.
Abstract: A centrifugal casting method and apparatus for casting molten metal into a mold. The casting apparatus includes a housing provided with a bottom surface and a retaining wall for minimizing a number of projectiles that escape the housing during casting operations. A prime mover is provided for imparting a centrifugal force on the molten metal, and an arm is coupled to the prime mover adjacent to a proximate end to be rotated about a rotational axis and to support a cradle for receiving the mold adjacent to a distal end. A crucible is to be coupled to the arm for supporting the molten metal to be cast into the mold, while a catch surface is disposed between the arm and the bottom surface of the housing to collect molten metal that is cast but not received within the mold.
Abstract: Apparatus for forming a cast component has a chamber for holding an alloy and which is rotated about an axis to separate an impurity from the alloy by centrifugal force. The chamber feeds a mould that is also rotating and into which the alloy is supplied to form a component by centrifugal casting.
Abstract: A bearing arrangement for a centrifugation injection mold, comprising an upper mold portion (10) and a lower mold portion (20), which are respectively and rotatively mounted to an upper bearing (30) and to a lower bearing (40), the latter comprising: a first flat ring (41) affixed to a machine structure (E) and presenting a radial gap that is internal in relation to the lower mold portion (20); an annular cage (42) bearing spheres (44) seated on the first flat ring (41), said annular cage (42) presenting radial gaps that are external and internal in relation to the machine structure (E) and to the lower mold portion (20), respectively; and a second flat ring (45) inferiorly seated on the spheres (44) of the annular cage (42) and maintaining radial gaps that are external and internal in relation to the machine structure (E) and to the lower mold portion (20), respectively, axially bearing the latter.
Abstract: Methods for making various titanium base alloys and titanium aluminides into engineering components such as rings, tubes and pipes by melting of the alloys in a vacuum or under a low partial pressure of inert gas and subsequent centrifugal casting of the melt in the graphite molds rotating along its own axis under vacuum or low partial pressure of inert gas are provided, the molds having been fabricated by machining high density, high strength ultrafine grained isotropic graphite, wherein the graphite has been made by isostatic pressing or vibrational molding, the said molds either revolving around its own horizontal or vertical axis or centrifuging around a vertical axis of rotation.
Abstract: To produce precision castings from a melt, use is made of a metallic casting wheel (1) which has an annular distribution channel (4) and a plurality of interchangeable casting moulds (6), each having at least one filling opening (6a). The melt quantity per casting operation is chosen here such that the casting moulds (6) and the distribution channel (4) are filled with the melt upon the rotation of the casting wheel (1) about its axis (A—A), in such a way that after the solidification of the melt the precision castings are held together by a ring of the casting material which is formed in the distribution channel (4), the so-called circulating material for new casting processes, and are removed from the casting wheel (1) together with the casting moulds (6), whereupon the precision castings are separated from the ring.
April 19, 2002
Date of Patent:
April 27, 2004
Ald Vacuum Technologies AG
Matthias Blum, Georg Jarczyk, Hans-Günther Fellmann, Peter Busse
Abstract: Methods for making various nickel based superalloys into engineering components such as rings, tubes and pipes by melting of the alloys in a vacuum or under a low partial pressure of inert gas and subsequent centrifugal casting of the melt in the graphite molds rotating along its own axis under vacuum or low partial pressure of inert gas are provided. The molds have been fabricated by machining high density, high strength ultrafine grained isotropic graphite, wherein the graphite has been made by isostatic pressing or vibrational molding.
Abstract: With the centrifugal casting apparatus, the rotating arm is never loosened to thereby obtain good casting quality even if rapid variation in speed is generated upon rotating of the rotating arm at high speed. The centrifugal casting apparatus is provided with a rotating shaft 51, a rotating arm 1 fixed to the shaft 51, a crucible 3, a mold 4 and the like provided at one end of the arm 1, and a balance weight 2 provided at the other end. The apparatus is provided with arm fixing bolts 12a, 12b for fixing the arm 1 to the shaft 51 and positioned so as to be deviated from the rotational center 15 of the shaft 51. The rotating shaft 51 is provided with fulcrum pins 18a, 18b serving as fulcrum for balance of the arm 1. The fulcrum pins 18a, 18b protrude from the shaft 51 when the balance of the arm 1 is adjsted, and retract into the shaft 51 when the arm 1 and the shaft 51 are fixed.
Abstract: An adjustable investment mold positioner includes a resilient band bent into a partial cylinder. Opposite ends of the band bound an opening at the side of the cylinder. A mold receiving member made of bent metal has side walls with bent connectors that are attached to the opposite ends of the band. A recess is formed between the side walls for receiving an oval investment mold. The outer cylindrical configuration of the positioner is readily engageable within the cradle of a conventional casting machine which is designed for normally receiving cylindrical investment molds. In this way, oval investment molds can be received in a secure manner within the conventional casting machines.
Abstract: The system comprises a main casting unit and a glove box unit for reworking cast items. The main casting unit has a frame with a casting chamber, a heating element, a vacuum, a supply of inert gas and a rotatable casting arm for spin casting molten material into a mold. The arm is adapted to removably mount a crucible and mold at one end and, an adjustable counterweight at the other end. The heating element can be moved into and out of the path of the arm and is adapted to heat metallic material in the crucible. The main casting unit also has a driver that projects into the chamber for driving the casting arm with reduced wear on seals between the chamber wall and the driver. A safety bar is provided to prevent the arm from spinning except when desired. The main unit also has electrical and gas conduit connectors for connecting the glove box unit to the main unit.
Abstract: A centrifugal caster arrangement including: a motor driven centrifuge arm and a weight arm connected to the centrifuge arm, with both arms being rotatable about a vertical axis. A counterweight is permanently fixed to the weight arm and a casting chamber is connected to the centrifuge arm. A melting crucible is disposed in the casting chamber. A plurality of muffle sets is provided with each muffle set including an exchangeable muffle cage and an associated casting muffle inserted therein. The casting chamber is provided with a region for mounting one of the muffle sets. Each exchangeable muffle cage is matched to its associated casting muffle according to size and weight so that the total weight of each respective muffle set is such magnitude that when each respective muffle set is mounted in the casting chamber and rotated about the vertical axis the centrifuge arm is in balance with the weight arm and the permanently fixed counterweight.
July 22, 1983
Date of Patent:
February 7, 1989
Fried. Krupp GmbH
Ronald Friedrich, Werner Hammecke, deceased, Ronald Friedrich
Abstract: Metal material is melted by moving the magnetic flux of electromagnets virtually perpendicular to an arc column to apply Lorentz force to the arc column and the metal material so that the arc column can move over the metal material surface. The movement direction and speed of the arc column are determined by detecting the arc voltage of the arc column. Feed back control is performed by comparing the obtained detection data with preset data so that optimum control is performed, and the molten metal is poured into a casting mold.
Abstract: A centrifugal casting device adapted to mold and cast a casting material melted by a casting material melting means, by the centrifugal force of a rotary arm, in a mold disposed on the centrifugal side of the arm through a casting crucible disposed at one end of the arm, in which device the melting means is designed to move outside the path of rotation of the arm at least when the arm is rotated so as to reduce the force of rotation of the arm to thereby increase efficiency of casting. And also a centrifugal casting device having the above features in which device the righting reaction of a charged compression spring is used as the driving force of the rotary arm and further included a clutch member and sensors so that the rotary arm stops as soon as possible at the end of casting and returns automatically to its normal position after stopping so as to be ready for the next step of casting and so as to automatically keep the force of rotation of the arm invariably constant.
Abstract: There is disclosed herein an embodiment of a vacuum centrifuge device for employment for filling cavities in material or in bodies such as, for example in ceramic multi-layer capacitors, with molten material, for example, metal.A chamber (12) in the device includes an outlet opening for the molten material, fashioned as a flow throttle (16), which is dimensioned, such that a dynamic pressure acting on all sides arises for a prescribed time span in the molten material (20) situated in the chamber (12) of the device, this dynamic pressure leading to the filling (of the cavities) in the material or in the bodies (15).
Abstract: Improved casting of titanum or alloy of titanium is obtained by using a crucible and a mold made of high-purity magnesium oxide and/or zirconium oxide. It is also possible for only the interior portion of the crucible to be made of such high-purity material, or for the mold to be made of copper or an alloy of copper. The mold and crucible can be used in a centrifugal-type casting machine or a compression-type casting machine. In either machine, discharge vents must be provided in the mold to connect the casting chamber with the outer atmosphere. An argon electric arc generated between a pivotable, tiltable cathode and an anode may be used for melting the titanium in the crucible. A high-frequency electric current can also be used to melt the titanium. By using the above apparatus, it is possible to obtain castings which are dimensionally accurate and do not have an external layer of fragile metal oxide or rough cavities.
Abstract: A melt receptacle (4) together with a muffle (5) attached thereto by a connector is situated on a centrifugal arm (2) of a centrifugal device, which arm rotates during the casting operation. On a common structural unit (8) are situated a preheater furnace (1) and the connector (9,13) in a manner to allow, respectively, for the conveyance of the muffle (5) from the preheater furnace and the fastening thereto for which connector there can be used a manipulator arm (12) which carries out only one shifting movement in one plane and engages the muffle (5).
Abstract: A centrifuge or casting machine has an arm disposed perpendicularly to the axis of a spring motor. One end of the arm supports a mold or flask. The opposite end includes a toothed scale for setting counterweights along the arm according to a set of predetermined locations which carry indicia related to the dimensions of the flask to be centrifuged. An overrunning clutch is included in the base of the centrifuge to engage the arm during wind-up and acceleration. The arm runs free for rotation during deceleration. Swing of the flask is limited to facilitate acceleration of the motor.
Abstract: A method and an apparatus for manufacturing a hollow curved member, especially a curved pipe as well as the curved member or pipe produced by the method and apparatus. A blank is formed by rotating fluid material in a mold having a toroidal cavity about an axis displaced a predetermined distance from the mean longitudinal axis of the cavity and solidifying the fluid material. The blank is removed from the mold and a toroidal inner surface is machined into the blank so as to provide a passageway therethrough. In the preferred embodiment, the toroidal cavity is circular in cross-section and has a circular arcuate axis and the inner surface is machined into the blank coaxial with the outer surface of the blank.
Abstract: Due to the inclination of a centrifuge arm of a centrifugal casting arrangement the mass of a muffle or retort and a compensation or balancing mass come to lie essentially in the same rotational plane. The infinite adjustment of a muffle or retort holder and the compensation or balancing mass is accomplished by a drive rod movably arranged within the centrifuge arm as well as by a gear rack driven by the drive rod and upon which there is seated the muffle holder. A housing structure containing a cover member prevents access to the centrifugal casting arrangement during operation of the centrifugal casting machine.
Abstract: A crucible for use with a broken arm-type centrifugal casting machine includes an elongated base section and a top section which is generally in the shape of a half cylinder, a large portion of the top section being removed by a cavity which creates a crucible floor, left and right side walls and a generally funnel-shaped channel which extends to a front surface at the front end of the crucible to provide a discharge opening. The right side wall is always correspondingly higher than the left side wall and both the left side wall and the right side wall increase in height and slope over toward one another as they extend toward the front end of the crucible until they merge at a point on a head portion of the top section which is on the left side of the crucible. The crucible floor includes a portion which narrows in width as it extends toward the front end of the crucible and slopes downwardly from horizontal at an angle of between about 10.degree. and 20.degree.
Abstract: A centrifugal ceramic casting furnace including a horizontal arm rotatably supported by the upper end of a vertical shaft driven by a motor and the arm having a casting ring cradle on one end, a muffle movable along said arm a limited distance toward and from the cradle and a counterweight device mounted upon the opposite end of the arm adjustably both longitudinally and upwardly in a manner to balance the opposite ends of the arm statically and also adjustably dispose the effective masses of the muffle and counterweight within a common horizontal plane to effect substantial freedom from vibration while the furnace is rotating at a centrifugal casting speed.
Abstract: A centrifugal caster comprising a motor driven centrifuge arm connected to a weight arm, both of which are rotatable about a vertical axis. A casting chamber is connected to the centrifuge arm and has a melting crucible disposed therein, and a counterweight is fixedly attached to the weight arm. The casting chamber is provided with a region for mounting a muffle set comprising a casting muffle inserted into an exchangeable muffle cage which is associated with the casting muffle according to size and weight, whereby the total weight of the muffle set is of such magnitude that upon rotation, the centrifuge arm is in balance with the weight arm and its fixedly attached counterweight.
March 26, 1981
Date of Patent:
December 6, 1983
Fried. Krupp Gesellschaft mit beschrankter Haftung
Ronald Friedrich, Werner Hammecke, deceased
Abstract: A centrifugal casting apparatus for dentistry comprises a rotating member or platform for the mold having a mold disposed on one side thereof, a rotating member for the crucible movably positioned at the center of revolution of the said rotating member for the mold and provided with a crucible and a melting means, and a driving mechanism therefor, whereby metal for dentistry uses charged into the crucible is heated to be molten, while the mold is caused to rotate about the periphery of the crucible by means of the rotating member for the mold, and, after melting of the metal for dentistry uses is completed, the rotating member for the crucible is brought into engagement with the rotating member for the mold for rotation therewith where the metal in the molten state is cast from the crucible into the mold through impact force produced upon transmission of rotation as well as centrifugal force after initiation of rotation.
Abstract: A centrifugal-casting machine includes a rotatable subassembly that has a generally planar support plate extending perpendicularly to the axis of rotation and a generally cylindrical shield portion extending from the periphery of the support plate. The shield rotates with the rotatable subassembly. A handle means slides in a track on the support plate and has a handle portion and a catch portion. In one position of the handle means, the catch portion engages a stop portion of the base in which the rotatable subassembly is journaled, and in the other position the catch portion does not engage the stop portion, so the rotatable subassembly can rotate freely. Winding, locking, and release can thereby all be effected by manipulation of the handle portion of the handle means.
Abstract: A centrifugal casting machine has an interchangeable casting head to permit the head to be rapdily and easily changed from one mold size to another. The head is removably affixed to the upper end of the motor driven shaft of the machine as by bolting to a flange on the shaft.
Abstract: The disclosure embraces a centrifugal casting apparatus of a character for casting comparatively small articles or objects of highly refractory metals, such as jewelry and similar articles, the centrifugal casting apparatus being enclosed in a housing, the arrangement having a motor-driven throwing arm and a secondary arm mounting components of the casting apparatus, the secondary arm being adapted upon energization of the motor to be centrifugally oscillated or rotated about a pivot axis to a diametrically aligned position with the throwing arm to rapidly accelerate flow of the molten casting metal into the mold, the apparatus including a closure or cover for the housing in association with means for automatically interrupting operation of the motor when the cover or closure is moved to an open position.
August 5, 1977
Date of Patent:
January 16, 1979
Dick Blick Company
William F. Goodrich, Robert C. Ingersoll, Donald W. Doman
Abstract: A centrifugal casting machine of the broken arm type has a rotatable casting arm on which a swing arm, which supports a crucible and a casting ring, is pivotably mounted. The crucible is tiltable so that upon initial rotation of the casting arm the crucible tilts to a pouring position to pour molten metal into the casting ring. A cam follower on the swing arm engages a cam on the base of the machine to hold the swing arm, during a start up period of rotation, in an orientation in which the flow path of molten metal lies in a plane approximately tangential to a circle concentric with the axis of rotation of the casting arm. This orientation and the tilting action eliminates splashing or other metal losses.After the initial period of rotation during which the metal enters the casting ring, the cam releases the swing arm for alignment with the casting arm so that the action of centrifugal force in filling the mold cavity is maximized.
Abstract: A centrifugal casting machine includes a plurality of split centrifugal molds which are successively brought to a casting station in which the molds are closed, clamped together and rotated rapidly while molten metal is fed through a central sprue to mold cavities therein. For feeding the molten metal, a vacuum chamber is provided at the casting station above the mold, and a feed pipe leading to a reservoir of molten metal extends into the vacuum chamber through a nozzle which discharges into a funnel communicating with the central sprue of the mold. Means are provided to create a vacuum condition within the vacuum chamber, the funnel, nozzle and the mold cavities when the mold is closed and clamped, whereby the molten metal is drawn by a siphoning action through the feed pipe and discharged from the nozzle into the mold cavities. The feed flow of the molten metal is accomplished solely by the vacuum condition which is timed to feed a selected charge of molten metal to the mold cavities.
Abstract: The following specification describes a safety shield assembly for centrifugal casting apparatus of the type used by hobbyists. The assembly comprises a ring wall encircling the path of rotation of the casting arm carrying the metal charge and mold. A top wall is provided having a central opening through which access is provided for heating the metal and releasing the arm carrying the charge and mold for rotation. The top wall is provided with a fixed wall portion and a lid hingedly secured along a diameter line of the ring wall and foldable into coincident relationship with the fixed top wall portion.An annular bottom wall adapted to be secured to a table top is also provided for the ring wall and a cup shaped housing adapted to be recessed in the table top is fixed to the bottom wall. The housing has a back wall for supporting the centrifugal casting apparatus with arms of the casting apparatus located just above the table top to reduce the height required of the ring wall.
Abstract: A centrifugal casting machine includes a rotatable shaft having a mounting plate for receiving a pair of molds containing the casting cavities. A passage in the shaft has one end connected to a source of vacuum and the other end opening in the plate. A conduit is provided from the casting cavities to the exterior of the molds. Connection means are provided for applying the vacuum in the passage to the cavity through the conduit. The vacuum so applied improves both the operation of the casting machine and the quality of the castings.
Abstract: A spring action portable centrifugal casting machine having a castor arm freely pivotable at a centrally balanced point has a horizontal pivotable extension arm attached thereto, and a crucible and flask entirely enclosed within a portable shield mounted on said extension arm.
Abstract: A system for centrifugal casting of induction melted metal includes a crucible and a porous mold secured to a casting arm. The casting arm is secured to a hollow rotatable shaft which includes two separate fluid channels extending axially therethrough. The shaft is supported on a rotary valve which provides separate flow communication with each flow channel. One flow channel provides pressurized argon to the crucible to prevent oxide formation during casting. The other channel provides a vacuum to the exterior of the mold to draw gasses out of the metal, aid in the argon flow into the mold, and to augment the centrifugal flow of the molten metal into the mold.
Abstract: Conoid surfaces can be generated by rotation of a material at different angles and under differing constraints. An axis of 45.degree. can produce hyperboloids; with perpendicular axes, concentric spheres can be produced; magnetic fields can be used to shape the lenses; and multielement lenses can be produced with special chambers.