US3735796A - Permanent mold risering - Google Patents

Permanent mold risering Download PDF

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Publication number
US3735796A
US3735796A US00210638A US3735796DA US3735796A US 3735796 A US3735796 A US 3735796A US 00210638 A US00210638 A US 00210638A US 3735796D A US3735796D A US 3735796DA US 3735796 A US3735796 A US 3735796A
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US
United States
Prior art keywords
riser
sand
mold
opening
resin
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00210638A
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English (en)
Inventor
A G Germain
D R Wiles
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Amsted Industries Inc
Original Assignee
Amsted Industries Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Amsted Industries Inc filed Critical Amsted Industries Inc
Application granted granted Critical
Publication of US3735796A publication Critical patent/US3735796A/en
Assigned to AMSTED INDUSTRIES INCORPORATED, A CORP. OF DE. reassignment AMSTED INDUSTRIES INCORPORATED, A CORP. OF DE. RELEASED BY SECURED PARTY (SEE DOCUMENT FOR DETAILS). Assignors: FIRST NATIONAL BANK OF CHICAGO, AS AGENT
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C23/00—Tools; Devices not mentioned before for moulding
    • B22C23/02—Devices for coating moulds or cores
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/08—Features with respect to supply of molten metal, e.g. ingates, circular gates, skim gates
    • B22C9/088—Feeder heads

Definitions

  • a graphite mold has riser openings lined with an insulator extending around the periphery and substantially across the bottom of the openings.
  • the bottom portion of the insulator is formed of facing sand and phenolic resin while the peripheral portion of the insulator is formed of a coarser backing sand and phenolic resin.
  • the insulator is baked by residual heat in the mold and decreases in thickness from the bottom toward the top of the riser opening.
  • the liners are generally made higher than necessary, but in these instances the portions of the resin-sand mix above the height of the liquid metal do not bake through, thus making later removal of the resin-sand mix more difficult. Still further, the noxious gases emitted from the riser openings make such manual dispensing not only extremely unpleasant but also hazardous to health.
  • mold cope is lifted and the metal in the riser must be torn away from the wheel as close to the wheel face as possible, thereby minimizing the clean up work in removing excess riser material from the wheel. It has been found that the cope may be lifted approximately 7 minutes after pouring, with the riser remaining intact and broken off from the wheelclose to the face thereof, because of the wedging action created by the draft in the riser insulator.
  • FIGURE is a fragmentary vertical sectional view through a riser opening of a graphite mold.
  • the numeral 10 designates a portion of a permanent, preferably graphite, mold such as might be used for the casting of steel railway car wheels substantially as shown in the aforementioned U.S. patent.
  • the mold has atop surface 12 and 2 a downwardly facing surface 14 which partially defines a casting cavity 16.
  • the mold is also provided with one or more riser openings 18 lined with an insulator'liner generally indicated at 20.
  • the liner 20 includes a pcripheral wall portion 22, which decreases in thickness from the bottom of the riser openings toward the top surface of the mold but preferably does not extend completely to the surface 12.
  • the liner also includes a second portion 24 extending substantially across the bottom of the riser opening and forming a continuation of the downwardly facing casting surface 14.
  • the riser insulators are formed in a heated mold, the mold either having been preheated or still hot as it is being recycled in casting operations.
  • the mold When the mold is placed in the production line where the riser liner is to be formed, it has a natural temperature gradient of approximately 465 at the downwardly facing surface defining the top of the casting cavity and approximately 380 F at the top surface of the mold.
  • a core baker 26-, shaped to conform to the contour of surface 14, is placed 'in the cavity under the riser opening 13, the core baker having a projection 28 which is smallerthan the riser opening 18 and extends slightly thereinto.
  • the entire liner may be formed of a backing sand-phenolic resin mixture, preferably a layer of fine facing sand is deposited across the bottom of the riser opening against the core baker 26, the sand having previously been mixed with about l k to 3 V2 percent by weight of a phenol formaldehyde resin binder.
  • the facing sand may be either very fine silica or may be zircon, as well known in the foundry art.
  • the remainder of the riser opening is then filled to the desired height with backing sand, a silica sand having coarser grains than those of the facing sand, which has previously been mixed with 1 r to 3 percent by weight of phenol formaldehyde resin binder.
  • the unbaked sand is dumped and the baking core is removed from the casting cavity.
  • a riser insulator liner having a bottom portion 24 preferably formed of facing sand, and a peripheral portion 22 which de creases in thickness toward the top surface of the mold.
  • the projecting portion 30 which was formed over portion 28 of the baking core is knocked out to provide a sprue having -a smaller cross section than the riser proper.
  • the riser insulator liner formed by the above described method will have a tensile strength of 450 to 600 pounds per square inch as compared to a tensile strength of 300 to 350 pounds per square inch for liners formed by the prior art plug method, thus affording greater protection and consequently longer life to the graphite mold and also assuring that the metal in the riser will be torn off the casting close to the top face thereof.
  • the advantages of the new process are that the riser insulators are equal in height thereby assuring that molten metal does not flow over the insulator and solidify against the graphite mold. Damage to the graphite is, therefore, decreased resulting in approximately a 25 percent savings in graphite consumption and a similar savings in the amounts of sand resin mix which must be used per mold.
  • the new method has also resulted in the elimination of at least two men per 8 hour shift in wheel casting plants.
  • the new method also permits the economical use of a facing sand mix at the bottom of the riser opening and a coarser back up sand mix for the peripheral portion of the riser openings.
  • a riser insulator in a riser opening of a graphite mold having a top surface and a downwardly facing surface defining a casting cavity communicating with the opening, the steps of: heating the mold to a certain temperature; permitting the mold to cool in air until the downwardly facing surface is at a second certain temperature and the top surface is at a temperature lower than the second temperature; closing the riser opening with a core baker positioned in the mold cavity; filling the riser opening to a predetermined height with a mixture of sand and thermosetting resin; and after a predetermined period of time, dumping the loose sand-resin mixture from the opening and leaving in the riser opening an insulator lining having a wall diminishing in thickness from the downwardly facing wall toward the top wall of the mold.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Mold Materials And Core Materials (AREA)
  • Casting Devices For Molds (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)
  • Motor Or Generator Current Collectors (AREA)
US00210638A 1971-12-22 1971-12-22 Permanent mold risering Expired - Lifetime US3735796A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US21063871A 1971-12-22 1971-12-22

Publications (1)

Publication Number Publication Date
US3735796A true US3735796A (en) 1973-05-29

Family

ID=22783668

Family Applications (1)

Application Number Title Priority Date Filing Date
US00210638A Expired - Lifetime US3735796A (en) 1971-12-22 1971-12-22 Permanent mold risering

Country Status (11)

Country Link
US (1) US3735796A (xx)
JP (1) JPS5146484B2 (xx)
AU (1) AU463182B2 (xx)
CA (1) CA981869A (xx)
DE (1) DE2251819C3 (xx)
ES (1) ES408042A1 (xx)
FR (1) FR2164570B1 (xx)
GB (1) GB1400888A (xx)
IT (1) IT966351B (xx)
SE (1) SE374678B (xx)
ZA (1) ZA727136B (xx)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5896912A (en) * 1995-04-27 1999-04-27 Hayes Wheels International, Inc. Method and apparatus for casting a vehicle wheel in a pressurized mold

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US24655A (en) * 1859-07-05 Hand printing-press
US2779075A (en) * 1950-10-13 1957-01-29 Griffin Wheel Co Cast article and method of making
US2819501A (en) * 1950-10-13 1958-01-14 Griffin Wheel Co Wheel mold
US2838816A (en) * 1955-09-14 1958-06-17 Griffin Wheel Co Permanent mold with sand dome
US3302919A (en) * 1965-11-12 1967-02-07 Abex Corp Apparatus for casting metal wheels
US3480070A (en) * 1967-02-16 1969-11-25 Abex Corp Permanent mold for casting a wheel

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3342942A (en) * 1964-06-05 1967-09-19 Automatic Elect Lab Party line exchange with interworking of different type switching units

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US24655A (en) * 1859-07-05 Hand printing-press
US2779075A (en) * 1950-10-13 1957-01-29 Griffin Wheel Co Cast article and method of making
US2819501A (en) * 1950-10-13 1958-01-14 Griffin Wheel Co Wheel mold
US2838816A (en) * 1955-09-14 1958-06-17 Griffin Wheel Co Permanent mold with sand dome
US3302919A (en) * 1965-11-12 1967-02-07 Abex Corp Apparatus for casting metal wheels
US3480070A (en) * 1967-02-16 1969-11-25 Abex Corp Permanent mold for casting a wheel

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5896912A (en) * 1995-04-27 1999-04-27 Hayes Wheels International, Inc. Method and apparatus for casting a vehicle wheel in a pressurized mold

Also Published As

Publication number Publication date
DE2251819B2 (de) 1973-12-20
SE374678B (xx) 1975-03-17
JPS4870624A (xx) 1973-09-25
DE2251819C3 (de) 1974-07-11
CA981869A (en) 1976-01-20
IT966351B (it) 1974-02-11
AU463182B2 (en) 1975-07-17
FR2164570A1 (xx) 1973-08-03
GB1400888A (en) 1975-07-16
AU4738072A (en) 1974-04-11
ZA727136B (en) 1973-06-27
FR2164570B1 (xx) 1974-10-25
ES408042A1 (es) 1975-11-16
JPS5146484B2 (xx) 1976-12-09
DE2251819A1 (de) 1973-07-12

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Legal Events

Date Code Title Description
AS Assignment

Owner name: AMSTED INDUSTRIES INCORPORATED, A CORP. OF DE., IL

Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:FIRST NATIONAL BANK OF CHICAGO, AS AGENT;REEL/FRAME:005070/0731

Effective date: 19880831