T.h.t. Presses, Inc.

Richard J Kamm

John L Jorstad

Michael J Loughman

Ted H Thieman

Ronald P Swarts

Michael W Thieman

Larry T Siefring

Eric W Cruse

A hermetically sealed disc drive comprising at least one aluminum alloy housing component manufactured with a thermally directed die casting press subassembly is disclosed. In one embodiment, the thermally directed die casting press subassembly comprises a thermally directed funnel gate that is skewed to sample molten material from an off-center portion of the shot sleeve. Disc drive housing components can be manufactured by injecting an aluminum alloy slurry from the shot sleeve through the thermally directed funnel gate and the injection nozzle into the die cavity. The aluminum alloy slurry may be a thixotropic slurry comprising a uniform primary aluminum particle size in the range of approximately 50 to 80 microns. The primary aluminum particles of cast products produced according to the methodology of the present disclosure, with the aforementioned particle size distribution, are free of encapsulated eutectic at the micron scale.

Thermally directed die casting suitable for making hermetically sealed disc drives

A rotor core for an electric motor includes a stack of laminations having peripherally spaced openings receiving copper bars with opposite end portions projecting from the stack. The core is mounted on an arbor and is inserted into a mold on a vertical die cast press having a shot chamber. The mold has upper and lower mold members defining annular cavities receiving end portions of the bars. Molten copper or aluminum is poured into the shot chamber and forced upwardly by a shot piston through passages in the lower mold member and into the cavity around the lower end portions of the bars. The pressurized molten metal solidifies and shrinks around the bar end portions to form an endring for the rotor. The core, endring and arbor are inverted and confined in the mold, and the casting steps are repeated to form the opposite endring.

Production of die cast rotors with copper bars for electric motors

A metal alloy is heated to a molten state and then poured into a shallow shot chamber defined by a shot sleeve and a shot piston of a vertical die cast press. A homogenizing member having L-shape arms projecting outwardly from a vertical shaft is inserted into the molten metal, and the shaft and arms are simultaneously rotated and orbited by a six axes robot for moving more solidified semi-solid metal cooled by the shot sleeve and shot piston into a more liquified semi-solid metal within a central portion of the shot chamber to form a homogenizing slurry. The force required to move the homogenizing member is used to determine the solid fraction of the slurry and to stop the homogenizing process after a predetermined force is detected. A hydraulic cylinder actuates the piston to transfer the semi-solid slurry upwardly from the shot chamber into a die cavity.

Semi-solid molding method and apparatus

A metal alloy is heated to a molten state, and a grain refiner may be added. The molten alloy is poured into a shallow chamber of a shot sleeve of a vertical die cast press and on top of a shot piston. The shot sleeve is transferred to an injection station while the molten alloy cools to a semi-solid slurry with a globular, generally non-dendritic micro structure. An inner portion of the shallow slurry is injected upwardly by the piston through a gate opening into a die cavity while an outer more solid portion of the slurry is entrapped in an annular recess. After the slurry solidifies, the shot piston retracts, and the shot sleeve is transferred to a position where the residual biscuit is removed. The shot piston may have internal grooves to provide a large heat transfer area for cooling water to absorb heat from the molten alloy.

Semi-solid molding method

A fiber reinforced porous preform is positioned within a die cavity defined by upper and lower die members, and the lower die member defines at least one gate opening in the center portion of a water cooled shot sleeve which receives a vertically moveable shot piston. The area of the gate opening is small relative to the area of the shot sleeve, and the lower die member defines an annular recess above the inner surface of the shot sleeve for entrapping a shell of pre-solidified metal. Air vent slots extend outwardly between the shot sleeve and lower die member and are closed by the shell of pre-solidified metal. In one embodiment, the shot sleeve and shot piston are non-circular or oval in cross-section; and the lower die member has a plurality of longitudinally space gate openings.

Vertical die casting press and method of producing die cast metal parts

A metal alloy is heated to a molten state and is poured into a shot sleeve of a vertical die cast press and on top of a shot piston. The shot sleeve is transferred to an injection station while the molten alloy is cooled to a semi-solid slurry and a globular, generally non-dendritic microstructure. A retractable cooling pin is temporarily inserted into a center portion of the slurry while in the shot sleeve to obtain optimum cooling. A center portion of the slurry is injected upwardly by the piston through a gate opening into a die cavity while an outer more solid portion of the slurry is entrapped in an annular recess. After the slurry solidifies, the shot piston retracts, and the shot sleeve is transferred to a position where the residual biscuit is removed. Another shot sleeve filled with the molten allow is transferred, and the process is repeated.

Semi-solid molding apparatus and method

A metal alloy is heated to a molten state, and a grain refiner may be added. The refined molten alloy is poured into a large diameter shot sleeve of a vertical die cast press and on top of a shot piston. The shot sleeve is transferred to an injection station while the molten alloy cools to a semi-solid slurry with approximately fifty percent solids and a globular, generally non-dendritic microstructure. A center portion of the slurry is injected upwardly by the piston through a gate opening into a die cavity while an outer more solid portion of the slurry is entrapped in an annular recess. After the slurry solidifies, the shot piston retracts, and the shot sleeve is transferred to a position where the residual biscuit is removed. A second shot sleeve filled with the molten alloy is transferred to the metal transfer station, and the process is repeated.

A fiber reinforced porous preform is positioned within a die cavity defined by upper and lower die members, and the lower die member defines a gate opening in the center portion of a water cooled shot sleeve which receives a vertically moveable shot piston. The area of the gate opening is small relative to the area of the shot sleeve, and the lower die member defines an annular recess above the inner surface of the shot sleeve for entrapping a shell of pre-solidified metal. Air vent slots extend outwardly between the shot sleeve and lower die member and are closed by the shell of pre-solidified metal. The structure prevents pre-solidified metal and air from entering the die cavity.

Vertical die casting press and method of producing fiber reinforced die cast metal parts

A vertical frame supports a rotary indexing table which carries a pair of vertical shot sleeves each having a shot piston with a depending shot piston rod. The shot sleeves are alternately indexed between a metal receiving station and a metal transfer station where a mold is supported above the table by a gate plate mounted on the frame. A hydraulic ejection cylinder and a substantially larger hydraulic shot cylinder are supported by the frame under the metal receiving and transfer stations, respectively, and laterally sliding couplings alternately connect the shot piston rods to the hydraulic cylinders when the table is indexed 180.degree.. Each shot piston and the gate plate form a biscuit which is retracted into the shot sleeve at the transfer station by the shot cylinder and is ejected at the receiving station by the ejection cylinder after the table and shot sleeves are indexed.

Vertical die casting press with indexing shot sleeves

A vertical die casting press includes a frame supporting a stationary lower horizontal platen which supports a base plate attached to a lower mold. An upper horizontal platen is supported for vertical movement between vertical columns by corner lift cylinders mounted on the lower platen, and the upper platen encloses hydraulic cylinders for actuating blades for releasably locking the upper platen to teeth on the vertical columns at a selected height. The upper platen carries a relatively movable intermediate platen which supports a base plate attached to an upper mold. After the upper platen is locked to the columns, a hydraulic load cell or cylinder within the upper platen clamps the intermediate platen and upper mold to the lower mold and lower platen. Molten die cast material is transferred through a horizontal ceramic cylinder from a ladle inlet to a vertical shot cylinder within the lower platen and lower mold, and a shot piston injects the material upwardly from the shot cylinder through runners and into cavities defined by the molds. The intermediate platen and lower platen enclose hydraulic cylinders for extending and retracting a set of rollers which engage tracks within the corresponding base plates to provide for quickly removing and replacing a set of upper and lower molds and corresponding base plates.

Vertical die casting press and method of operation

An ingot having a predetermined amount of electrolytic copper and a small percentage of boron copper alloy is rapidly heated to about 2,100.degree. F. in a clay graphite crucible by induction coils surrounding the crucible. The crucible and the entire amount of molten copper are automatically transferred to a cavity defined within a shot cylinder above a vertically movable shot piston of a vertical die casting press. A shuttle moves a lower end ring mold and a stack of connected rotor laminations into a position above the shot cylinder, and the press moves an upper end ring mold downwardly to clamp the stack between the molds and against the cylinder. The molten copper is rapidly injected upwardly through gates within the lower mold and into end ring cavities within the molds and also through connecting aligned bar slots within the stack of laminations with a shot pressure of about 2250 psi. After the copper solidifies by circulating cooling water within the molds, the press opens and the die cast rotor and lower mold are transferred by the shuttle to a position where the rotor is ejected upwardly from the lower mold by a fluid cylinder. The copper rotor is annealed by induction heating the rotor to about 1,500.degree. F. and allowed to air cool.

Growing community of inventors

Vandalia, OH, United States of America

Richard J Kamm