Through Porous Mold Body Patents (Class 164/255)
  • Patent number: 4874029
    Abstract: A countergravity casting process involves holding an inherently unstable mass of particulate mold material in an open bottom container around a destructible pattern therein by exerting external fluid pressure, such as atmospheric pressure, on a bottom side of the particulate mass in excess of internal pressure in the container. The container and an underlying molten metal pool are relatively moved to place the bottom side of the particulate mass in the pool. Molten metal is drawn through an ingate to the pattern to destroy and replace the pattern in the particulate mass. When the container and pool are relatively moved to extract the bottom side from the pool after casting, the particulate mold material is held in the container around the metal replacing the pattern by the external/internal pressure differential between the bottom side of the particulate mass and interior of the container.
    Type: Grant
    Filed: May 9, 1988
    Date of Patent: October 17, 1989
    Assignee: General Motors Corporation
    Inventor: George D. Chandley
  • Patent number: 4865113
    Abstract: Apparatus for the vacuum-assisted, countergravity casting of thin-walled metal parts includes a plurality of expendable casting molds supported on a top side of a reusable drag slab. Each casting mold includes a mold cavity and a mold ingate passage extending from the mold cavity into registry with a respective underlying slab ingate passage that extends between the top side and a bottom side of the drag slab and that optionally includes a molten metal filter therein. When the bottom side of the drag slab is immersed in an underlying molten metal pool with the mold cavities evacuated, the molten metal is drawn upwardly through each slab ingate passage and the molten metal filter therein and then through each mold ingate passage registered therewith into each mold cavity. The molten metal filter in each slab ingate passage removes inclusion-forming impurities from the molten metal as it is drawn upwardly into each mold cavity.
    Type: Grant
    Filed: August 30, 1988
    Date of Patent: September 12, 1989
    Assignee: General Motors Corporation
    Inventors: Karl D. Voss, James B. Mercer, Gary F. Ruff
  • Patent number: 4862946
    Abstract: A vacuum countergravity casting apparatus includes a vacuum chamber and a gas permeable mold sealingly mounted in the mouth of the chamber and comprising a gas permeable upper mold member and a lower mold member held in sealing engagement at a mold parting plane without glue. To this end, the upper mold member includes an exterior mold surface confronted by the vacuum chamber and a plurality of vacuum passages extending between the exterior mold surface and a bottom parting surface thereof to expose an effective area of the lower mold member to subambient pressure in the chamber sufficient to urge the lower mold member into sealing engagement with the upper mold member at the mold parting plane. The vacuum chamber includes a mold-engaging stop member for engaging the upper mold member and limiting movement of the upper mold member inwardly of the vacuum chamber away from the lower mold member as the latter is urged into sealing engagement therewith.
    Type: Grant
    Filed: November 23, 1988
    Date of Patent: September 5, 1989
    Assignee: General Motors Corporation
    Inventor: George D. Chandley
  • Patent number: 4862945
    Abstract: An apparatus for the vacuum, countergravity casting of molten metal includes a bottom drag member and a casting mold member thereon engaged together at a parting plane. A valve member is disposed adjacent the parting plane in an ingate to a mold cavity formed at least in part in the casting mold member and is movable between a valve seat on the bottom drag member and a stop surface on the casting mold member to permit filling of the mold cavity in countergravity manner from an underlying molten metal pool when the bottom drag member is immersed therein and to prevent backflow of the molten metal from the mold cavity when the bottom drag member is withdrawn from the pool after mold filling and before solidification of the molten metal in the mold cavity.
    Type: Grant
    Filed: August 30, 1988
    Date of Patent: September 5, 1989
    Assignee: General Motors Corporation
    Inventors: Anthony C. Greanias, James B. Mercer
  • Patent number: 4858672
    Abstract: Apparatus for vacuum countergravity casting includes a gas permeable upper mold member and a lower mold member engaged to the upper mold member. A gas impermeable member includes a central portion overlying the upper surface of the upper mold member and in contact therewith at a plurality of spaced apart contact regions disposed across the horizontal dimension of the upper surface and further includes a peripheral portion in sealed relation substantially about the upper mold member. Reduced pressure is applied between the gas impermeable member and the upper mold member to draw molten metal into mold cavities therein when the lower mold member is placed in a molten metal pool. Simultaneously, ambient pressure, such as atmospheric pressure, above the gas impermeable member is transmitted by the contact regions to the upper mold member in opposition to ambient pressure transmitted to the lower mold member to substantially reduce bending stresses in the mold.
    Type: Grant
    Filed: May 25, 1988
    Date of Patent: August 22, 1989
    Assignee: General Motors Corporation
    Inventor: George D. Chandley
  • Patent number: 4834166
    Abstract: This invention relates to a die casting machine in which high pressure is applied to molten metal to inject and fill the molten metal all over the mold before the molten metal is solidified to continuously mold molded articles (products), which have a beautiful casting surface and a high dimensional precision, every cycle of the machine. One or both of a fixed mold or a movable mold, which serves as a molding mold, and a core incorporated into one or both the molds are formed of high strength ceramics, and in addition, a movable hob for pressurizing molten metal injected and filled into both the fixed and movable molds is formed of high strength ceramics thereby providing a mold construction which is excellent in mechanical characteristics such as strength, hardness, breaking toughness and the like and having durability and pressure resistance enough to withstand high temperature thermal shock and high pressure, and being capable of easily controlling the temperature distribution within the mold.
    Type: Grant
    Filed: January 6, 1987
    Date of Patent: May 30, 1989
    Inventor: Akio Nakano
  • Patent number: 4830085
    Abstract: A lost foam casting system (2) is provided with vacuum lift of molten metal (16) to an evaporative foam pattern assembly (8) surrounded by unbonded particulate media such as sand (6) in a flask (4). A gas permeable member (34, 70) or passage (72, 74) is provided between the sand and a vertical fill passage (20) to apply vacuum from the sand to the fill passage such that molten metal is vacuum lifted through the fill passage to the foam pattern assembly, such that the foam material vaporizes as the molten metal advances upward and is replaced by the metal in the shape of the pattern assembly.
    Type: Grant
    Filed: February 26, 1988
    Date of Patent: May 16, 1989
    Assignee: Brunswick Corporation
    Inventors: Terrance M. Cleary, Raymond J. Donahue, William G. Hesterberg, Lawrence I. Toriello
  • Patent number: 4828011
    Abstract: Immersion-type vacuum countergravity casting apparatus having a vacuum chamber including spring means for pressing the mold portions sealingly together and/or resisting destructive inward flexure of the mold. A split vacuum chamber, including a floating lower skirt portion, avoids the creation of stress concentration sites between the chamber and the mold.
    Type: Grant
    Filed: June 24, 1988
    Date of Patent: May 9, 1989
    Assignee: General Motors Corporation
    Inventors: Paul H. Hafer, Bradley W. Hanson, Jeffrey D. Porter, James Smith, Jr.
  • Patent number: 4828006
    Abstract: An improved lost foam pour box and lost foam casting process wherein the improvements are positioning one or more fluid permeable separators, such as well points, within the contained volume of the box so that the gasses generated in the lost foam casting process can be vented to the exterior of the box by passing through the separators. By positioning the separators within the box, a larger box can be used and more castings can be made within with reduced burn-in and porosity defects in the resulting castings.
    Type: Grant
    Filed: October 13, 1987
    Date of Patent: May 9, 1989
    Inventor: A. Dean Vander Jagt
  • Patent number: 4825933
    Abstract: Apparatus for the vacuum countergravity casting of metal in shell molds including a gas-permeable upper shell mold portion secured to a bottom mold portion and together secured to the mouth of a vacuum box by a plurality of threadable mounting sites engaged by self-tapping threads on the ends of rotatable shafts reciprocally slidable through the ceiling of the box. Each shaft has a stop fixed thereto at a predetermined distance above the threads for pressing the upper shell mold portion into sealing engagement with the bottom mold portion in order to eliminate the need to glue the upper and lower mold portions together.
    Type: Grant
    Filed: June 24, 1988
    Date of Patent: May 2, 1989
    Assignee: General Motors Corporation
    Inventors: Karl D. Voss, James B. Mercer
  • Patent number: 4809767
    Abstract: Apparatus for the countergravity casting of molten metal by immersing of gas-permeable multi-piece mold in an underlying pot of molten metal includes a motor actuated plunger for pressing the pieces into sealing engagement with each other without the need for glue therebetween and for resisting destructive flexure of the mold incident to the application of casting vacuum thereto.
    Type: Grant
    Filed: June 24, 1988
    Date of Patent: March 7, 1989
    Assignee: General Motors Corporation
    Inventors: Karl D. Voss, James B. Mercer, Anthony C. Greanias
  • Patent number: 4798237
    Abstract: This invention concerns an improvement in a molding die for use in casting in which a metal article is molded by charging a molten metal to the inside of a molding die comprising paired male and female dies, and then cooling the temperature of the molten metal to a solidification region and a solidification range where the solid phase and the liquid phase are present together, wherein one or both of paired male and female dies constituting the molding die equipped retractably with a pressurizing insert for applying the pressure to the molten metal charged to the molding die is made of ceramics thereby obtaining a molding die that can facilitate the control for the temperature distribution over the entire molding die, particularly, within the molding die upon cooling to solidify the molten metal, as well as having sufficient strength such as thermal shock resistance, shock resistance and durability enabling to mold a high temperature metal article by solidifying the high temperature molten metal of about 600.
    Type: Grant
    Filed: November 25, 1986
    Date of Patent: January 17, 1989
    Inventor: Akio Nakano
  • Patent number: 4791977
    Abstract: An apparatus and method for counter-gravity casting of molten metal, in a gas permeable mold with a fill passage upper end above the lateral communication of the passage with other mold cavities. The mold is filled by low pressure in a chamber sealed about the mold while the mold fill passage is communicated with the molten metal. Provision is made for maintaining, during filling, the upper part of the mold fill passage at a lower pressure than that in the chamber external to the mold.
    Type: Grant
    Filed: May 7, 1987
    Date of Patent: December 20, 1988
    Assignee: Metal Casting Technology, Inc.
    Inventor: George D. Chandley
  • Patent number: 4784207
    Abstract: An apparatus for lost-wax castings wherein metal is melted in a vacuum vessel, and wherein there are provided vacuum pumps for producing a higher degree of vacuum around the mold during the casting of the molten metal.
    Type: Grant
    Filed: October 16, 1987
    Date of Patent: November 15, 1988
    Assignee: Mario Di Maio S.p.A.
    Inventor: Eliseo Di Maio
  • Patent number: 4781237
    Abstract: A method and apparatus for filling a mold having walls porous to gases by exposing external surfaces of the mold to a vacuum while filling the mold through an opening exposed to a higher pressure. The mold may be rotated at speeds sufficient for centrifugal forces to be produced to assist in filling cavities in the mold.
    Type: Grant
    Filed: July 25, 1986
    Date of Patent: November 1, 1988
    Inventor: Peter Sing
  • Patent number: 4745962
    Abstract: Apparatus for the shaping of metal in a bottom-gated mold by the vacuum-induced countergravity casting method including an upstanding levee on the periphery of the drag and circumscribing the chamber-to-mold joint and/or the cope-to-drag joint for isolating such joint(s) when the mold is immersed in an underlying melt.
    Type: Grant
    Filed: July 27, 1987
    Date of Patent: May 24, 1988
    Assignee: General Motors Corporation
    Inventors: James B. Mercer, Karl D. Voss
  • Patent number: 4742863
    Abstract: A permanent casting mold has its casting cavity coated with a sand liner of varying thickness. The liner is thicker where the cast article section is thinner and the liner is thinner where the cast article section is thicker so as to permit the thicker sections to cool faster while the thinner sections cool slower. The different thicknesses of the liner are correlated so that the respective sections of the article are sufficiently cooled at about the same time for removal of the article from the mold. The mold is a cope and drag-type flask mold whose casting cavity halves are oversized relative to the cast article. The sand liner is formed therein by temporarily positioning a pattern within the permanent casting cavity halves and sand filling the space between the pattern and cavity wall. The exterior surface of the pattern corresponds to the cast surface of the article.
    Type: Grant
    Filed: April 27, 1987
    Date of Patent: May 10, 1988
    Inventor: Raymond H. Witt
  • Patent number: 4727922
    Abstract: A mold and method for producing, or casting a high-melting metal article from a high-melting metal having a melting point of about 900.degree. to 1600.degree. C.
    Type: Grant
    Filed: November 25, 1986
    Date of Patent: March 1, 1988
    Inventor: Akio Nakano
  • Patent number: 4673025
    Abstract: Apparatus and method for providing a constant level of molten metal to a mold in gas permeable shell mold casting. The apparatus includes a furnace for melting and holding metal to be cast. Structure is provided for locating a mold to be filled in casting relationship with the molten metal in the furnace and for causing molten metal to be drawn from the furnace into the mold. Structure responsive to the sensor is provided for tilting the furnace relative to the mold causing the level of the molten metal to remain constant relative to the mold as the mold is being filled.
    Type: Grant
    Filed: April 4, 1986
    Date of Patent: June 16, 1987
    Assignee: Inductotherm Corporation
    Inventor: John H. Mortimer
  • Patent number: 4658880
    Abstract: Apparatus for the vacuum, countergravity casting of metal in shell molds including a gas-permeable shell mold secured to the mouth of a vacuum box by a plurality of threadable mounting sites atop the mold engaged by self-tapping threads on the ends of rotatable shafts reciprocably slidable through the ceiling of the vacuum box.The mounting sites may comprise upstanding lugs atop the mold.
    Type: Grant
    Filed: June 9, 1986
    Date of Patent: April 21, 1987
    Assignee: General Motors Corporation
    Inventor: Karl D. Voss
  • Patent number: 4641703
    Abstract: Apparatus for the countergravity, shell-mold casting process comprising a gas-permeable shell mold sealed in the mouth of a vacuum chamber and a hollow, expendable, gas-permeable, thermally degradable, core disposed with the molding cavity for engulfment and retention by the metal being cast. The core defines a central evacuation cavity and an unobstructed vent for exhausting the evacuation cavity into the vacuum chamber such that the pressure in the evacuation cavity is substantially equal to that in the vacuum chamber during casting.
    Type: Grant
    Filed: November 27, 1985
    Date of Patent: February 10, 1987
    Assignee: General Motors Corporation
    Inventors: Karl D. Voss, Mark A. Datte, Gary F. Ruff
  • Patent number: 4632171
    Abstract: A thin-walled, resin-bonded sand, shell mold for the vacuum counter-gravity casting of metal comprising cope and drag halves glued together at a parting line therebetween. The drag includes a flange extending beyond the periphery of the cope which flange has an upper sealing surface formed by a drag-shaping pattern for effecting a seal with the mouth of the vacuum chamber used to fill the mold.
    Type: Grant
    Filed: September 26, 1984
    Date of Patent: December 30, 1986
    Assignee: General Motors Corporation
    Inventor: Roger L. Almond
  • Patent number: 4616691
    Abstract: Apparatus for the vacuum countergravity casting of metal including an elastomeric sealing gasket substantially thermally insulated, conduction-wise, from the underlying melt's heat by the mold-forming material and shielded from the melt's radiant heat by a surrounding skirt depending from the vacuum box.
    Type: Grant
    Filed: December 9, 1985
    Date of Patent: October 14, 1986
    Assignee: General Motors Corporation
    Inventor: Karl D. Voss
  • Patent number: 4606396
    Abstract: Casting metal in rigid, self supporting, gas permeable molds with one or more mold cavities for molding one or more parts, in which the mold cavities have gate passages with their lower open ends at the lower surface of the mold, by submerging the lower ends of the gate passages beneath the surface of molten metal and applying a reduced pressure to the upper surface of the mold to fill the mold cavities with molten metal to produce unconnected metal parts or groups of parts.
    Type: Grant
    Filed: January 27, 1984
    Date of Patent: August 19, 1986
    Assignee: Hitchiner Manufacturing Co., Inc.
    Inventors: George D. Chandley, Richard L. Sharkey
  • Patent number: 4532976
    Abstract: Unitary, rigid, self-supporting, gas permeable, low temperature bonded, sand grain molds having peripheral side surfaces extending between vertically spaced upper and lower surfaces with mold cavity means spaced therebetween connected to gate passage means having lower open ends exposed at said lower surface, adapted to be filled with molten metal through the gate passage means by applying reduced pressure to the top surface of the mold while its lower surface with the gate passage means lower open ends are submerged in molten metal, are provided with enclosed gas collection void means adjacent to and spaced from each of the mold cavity means, the gate passage means and the upper and lower mold surfaces for collecting gases from the cavity means and gate passage means during filling of the cavity means for controlled removal of gases from the void means through the upper mold surface by application of reduced pressure thereto.
    Type: Grant
    Filed: June 13, 1984
    Date of Patent: August 6, 1985
    Assignee: Hitchiner Manufacturing Co., Inc.
    Inventor: George D. Chandley
  • Patent number: 4512383
    Abstract: A vertical pressure die casting apparatus comprising a stationary member, an air-permeable die detachably mounted on the stationary member and formed with a cavity including a downwardly open runner portion and a casting cavity portion communicating with the runner portion, a die clamping member to clamp the die vertically between the stationary member and the die clamping member, a sleeve held in position with respect to the stationary member and having a bore upwardly communicating with the runner portion of the cavity in the die, and a power cylinder provided below the die and having a cylinder body fixedly held in position with respect to the stationary member and a piston rod extending upwardly into the sleeve and vertically slidable in the sleeve.
    Type: Grant
    Filed: December 14, 1982
    Date of Patent: April 23, 1985
    Assignee: Nissan Motor Company, Limited
    Inventors: Shunsuke Suzuki, Masanobu Mori, Takeshi Miyata
  • Patent number: 4457352
    Abstract: Air is caused to flow through the resin bonded mold to aid combustion of the resin binder to form a low BTU gas fuel. Casting heat is recovered for use in a waste heat boiler or other heat abstraction equipment. Foundry air pollution is reduced, the burned portion of the molding sand is recovered for immediate reuse and savings in fuel and other energy is achieved.
    Type: Grant
    Filed: April 19, 1982
    Date of Patent: July 3, 1984
    Inventor: Karl D. Scheffer
  • Patent number: 4340108
    Abstract: Casting metal in rigid, self supporting, gas permeable molds with one or more mold cavities for molding one or more parts, in which the mold cavities have gate passages with their lower open ends at the lower surface of the mold, by submerging the lower ends of the gate passages beneath the surface of molten metal and applying a reduced pressure to the upper surface of the mold to fill the mold cavities with molten metal to produce unconnected metal parts or groups of parts.
    Type: Grant
    Filed: May 29, 1980
    Date of Patent: July 20, 1982
    Assignee: Hitchiner Manufacturing Co., Inc.
    Inventors: George D. Chandley, Richard L. Sharkey
  • Patent number: 4325424
    Abstract: A low vacuum is applied to selected surface areas of a resin bonded sand mold to draw ambient air into selected portions of the mold. The air entering the mold burns out a significant portion of the resin binder to form a low BTU gas fuel and to recover casting heat for use in a waste heat boiler or other heat abstractions device. Therefore, foundry air pollution is reduced, the burned out portion of the molding sand is recovered for immediate reuse, and a savings in fuel and energy.
    Type: Grant
    Filed: March 14, 1980
    Date of Patent: April 20, 1982
    Inventor: Karl D. Scheffer
  • Patent number: 4129164
    Abstract: In a method for reduced-pressure mould production, a plurality of mould flasks are simultaneously evacuated by evacuating means, and in which production of the moulds is carried out while moving the mould flasks sequentially through a mould shaping position, a pouring position and a mould disintegrating position. Evacuation is effected by first evacuating means during a period from the beginning of mould shaping to the beginning of mould pouring and a period after pouring, and evacuation is effected more strongly by second evacuating means during the period of pouring.
    Type: Grant
    Filed: January 24, 1977
    Date of Patent: December 12, 1978
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventor: Kiyoshige Torikai
  • Patent number: 4113001
    Abstract: Moulding apparatus comprises a mould box support structure having spaced support members for receiving and supporting lug members formed at opposite ends of a mould box. The mould box is formed in two separable parts each incorporating at opposite ends thereof a lug member having a substantially semi-circular outside profile so that when the mould box parts are abutted the lug members of one box part register with the lug members of the other box part to provide a substantially circular surface which acts as a bearing for the mould box so that the box can be rotated on the support structure for convenience of handling. In one form the mould box is for use with the V-Process of moulding and suction is applied to the chambers within the walls of the mould box parts via conduits extending through the lug members of respective box parts. In one form the support structure includes a circular table which is indexed so that a mould box is sequentially processed through several processing stations.
    Type: Grant
    Filed: November 22, 1976
    Date of Patent: September 12, 1978
    Inventor: John Workman
  • Patent number: 4111255
    Abstract: The invention provides a new apparatus and method for forming thin metal parts of simple or intricate shape and depositing the same onto selected receiving surfaces. The parts may be in the form of wire leads which are bonded to the receiving surfaces. The invention consists in providing a hollow tool which includes a porous body with an exposed surface having a selected two-dimensional or three-dimensional geometry, immersing the surface of the porous body in a melt of a metal which will not wet the surface, pulling the tool away from the metal while applying a suction force to the porous body so that a portion of the melt will adhere to the surface, bringing the tool into contact with a receiving surface, and cooling the surface and removing the suction force so that the adhering portion of the melt will be deposited as a solid or partially solidified body onto the receiving surface.
    Type: Grant
    Filed: March 21, 1977
    Date of Patent: September 5, 1978
    Assignee: Seal Incorporated
    Inventors: Theodore H. Krueger, Jr., Robert Eller, John O'Brien, William L. Robbins
  • Patent number: 4036283
    Abstract: An improvement in a rail conveyor apparatus. The improvement is composed of a plurality of rail conveyor trucks coupled together and movably supported on a track with at least one foundry molding box being mounted on each rail conveyor truck. Each of the foundry molding boxes has a connector member thereon having first and second ends. A conduit connects the first ends of the connector members on each of the rail conveyor trucks. A vacuum source and another conduit is provided for coupling the vacuum source to a pair of coupling members. Valves are provided in the second-mentioned conduit for alternately connecting the coupling members to the vacuum source. Coupling devices are provided for effecting a coupling of at least one of the coupling members to the second end of one of the connector members on one of the conveyor trucks prior to an uncoupling of the other of the coupling members from the second end of another connector member on another rail conveyor truck.
    Type: Grant
    Filed: July 22, 1976
    Date of Patent: July 19, 1977
    Assignee: Heinrich Wagner Maschinenfabrik
    Inventor: Herbert Grolla
  • Patent number: 4034793
    Abstract: In a process for casting a plate grid for a lead-acid storage battery comprising the steps of preparing a casting die assembly including two interengagable die halves between which is formed a casting cavity to cast a plate grid therein and pouring a molten metal of lead or lead alloy into said casting cavity to form said plate grid therein, an air in said casting cavity is vented through gaps between said die halves and then through a narrow air passage in at least one venting member received in either of said die halves so that said venting member is flush with the casting surface of the corresponding die half, said venting member at the top surface having cavity forming portions operatively associated with said die halves.
    Type: Grant
    Filed: January 19, 1976
    Date of Patent: July 12, 1977
    Assignee: Shin-Kobe Electric Machinery Co., Ltd.
    Inventors: Tomoyuki Okura, Takashi Tatsumi, Hitoshi Watanabe, Hiroaki Murayama, Yoichi Kobayashi
  • Patent number: 4027719
    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.
    Type: Grant
    Filed: March 24, 1976
    Date of Patent: June 7, 1977
    Assignee: Ultratek International, Inc.
    Inventor: Willy Strempel
  • Patent number: 4014529
    Abstract: A device for vacuum-refining of molten metal, comprising a vacuum chamber and an electromagnetic pump with an annulus-section line to which metal feed and discharge pipe lines are connected. The latter is coupled with the central portion of the annulus-section line. For pouring vacuumed metal into a foundry mould provision is made for a metal pouring pipe line connected to the metal discharge pipe line. The device envisages a higher degree of metal refining to free it from harmful impurities and a possibility of pouring metal directly into foundry moulds.
    Type: Grant
    Filed: January 15, 1975
    Date of Patent: March 29, 1977
    Inventors: Leonid Petrovich Puzhailo, Vitaly Petrovich Polischuk, Viktor Konstantinovich Pogorsky
  • Patent number: 4010020
    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.
    Type: Grant
    Filed: December 18, 1973
    Date of Patent: March 1, 1977
    Inventor: Stephen Wyden
  • Patent number: 4007772
    Abstract: A portable vacuum investment casting apparatus includes a box-like housing having an upper generally flat supporting wall with a vertical conduit terminating in an opening in the top wall. A vacuum conduit is connected to the vertical conduit and terminates in an outer sidewall in large and small conical connectors to receive a conventional shop or household vacuum cleaner hose. A manually adjustable valve is connected in an exhaust pipe from the vacuum conduit for controlling the vacuum level. The apparatus is powered from a conventional household type vacuum cleaner device or similar fan unit which establishes a relatively high air flow with a relatively low vacuum. A small vacuum gauge tube is mounted on the front wall adjacent to the vacuum setting control. The top end is connected to the vertical conduit and the lower end has a supply tube with an adjustable end member to set the initial liquid level.
    Type: Grant
    Filed: November 6, 1974
    Date of Patent: February 15, 1977
    Inventors: Donald O. Laedtke, Myron W. Jackson
  • Patent number: 3955612
    Abstract: A method and apparatus for melting and fine-casting precious metals in which a closed, gas-pressurizable crucible is arranged on top of a molding cell and connected thereto via a valve-controlled tapping passage. The melt is tapped under pressure into an evacuated mold, thereby inhibiting melt evaporation and improving melt flow into the mold branches.
    Type: Grant
    Filed: June 19, 1974
    Date of Patent: May 11, 1976
    Inventor: Alfons Schultheiss