US2472246A - Centrifugal casting machine - Google Patents

Description

J1me 1949- R. E. CHRISTIAN EIAL 2,472,246

. CENTRIFUGAL CASTING MACHINE Filed Sept. 17, 1945 3 Sheets-Sheet 1 IN'VENTORS RODNEY ecumsnm By ALFRED W.WIDERSTEDT ATTORNEYS June 7, 1949. R. E. CHRISTIAN ETAL CENTRIFUGAL CASTING MACHINE 3 Sheets-Sheet 2 Filed Sept. 1'7, 1945 nvmvroxs aoomzv E. CHRISTIAN fiY LFRED W.WIDERSTEDT ATTORNEYs J 1949- R. E. CHRISTIAN ETAL 2,472,246

CENTRIFUGAL CASTING MACHINE Filed Sept. 1'7, 1945 3 Sheets-Sheet 3 FIG.5

H2 H IN H' 2 6% -$-s L 4 INVENTORS N RODNEY E.GHRISTIAN BY ALFRED W.WIDERSTEDT ATTORNEYS ed in bearings D in the standards A.

Patented June 7, 1949 2,472,246 oanramccar. CASTING MACHINE Rodney E. Christian, Royal Oak, and Alfred W. Widerstedt, Detroit, Mich., assignora' to Kerr Manufacturing Company, a corporation of Michigan Application September 17, 1945, Serial No. 616,850

8 Claims. (Cl. 22-65) The invention relates to centrifugal casting machines and has among its objects, first, the obtaining of a construction in which the work including the mold and the crucible for the molten metal can be quickly inserted within and removed from the centrifugal holder; second, to provide for accurately determining the pressure on the molten metal within the mold which is centrifugally developed; and, third, to provide adjustable means for counterbalancing exchangeable molds and crucibles. With these and other objects in view the invention consists in the construction as hereinafter described.

In the drawings:

Fig. 1 is a side elevation of the machine;

Fig. 2 is a plan view thereof;

Fig. 3 is an end elevation;

Fig. 4 is a cross section on line 4-4, Fig. 1, showing the centrifugal holder in position for loading with the mold and crucible;

Fig. 5 is a cross section on the line 5--5, Fig. 4;

Fig. 6 is a cross section on the line 8-6, Fig. 4; and

Fig. 7 is a section through the clutch.

As illustrated in Figs. 1 to 3, A is a frameincluding a base portion A and spaced standards A B is a cylindrical casing centrally provided with diametrically oppositely extending trunnions C and C which are respectively mount- E is a motor mounted on the base and F is a variable speed transmission between said motor and the trunnion C by which the latter and the casing B may be revolved at a predetermined speed.

The casing B has at one end a fixed head or closure G and at its opposite end a quickly removable and replaceable closure H. The latter is preferably formed by a cap having a flange I-I' overlapping the end of the casing and a series of spaced lugs H thereon. H are pins extending radially inward from the flange H which are adapted to pass through the spaces between the lugs H and to interlock with the latter by a rotation of the cap. This forms in efiect a bayonet joint by which-the cap may be quickly locked to the casing after the loading of the latter with the work. The molds I are preferably of the type formed of investment compound retained within a cylindrical metal casing I. At oneend is a hopper-like recess I for receiving the molten metal and which is connected by a sprue I to the mold cavity (not shown). J is a crucible in which the metal'to be cast is melted in a suitable external furnace. This crucible is engageable with an annular seat member K preferably formed of a metallic outer ring K internally fitting and slidable within the cylindrical casing B and a refractory lining K=1for directly engaging the crucible. The member K is yieldably supported by a coil spring member L, which also is within the casing B and has an abutment in the opposite end portion thereof. Thus, in loading the machine the crucible J containing the molten metal is removed from the furnace and inserted through the open end of the casing B into engagement with the seat member K. The mold I is then placed within the casing with its recessed end adjacent to the upper end of the crucible and bearing thereagainst, after which the cap H is engaged with and locked to the casing. This cap is provided with an adapter H for fitting the outer end of the mold I and holding it in registration with the crucible. During engagement of the cap the mold I is pressed inward which is permitted by the yielding of the spring L and the seat member K, the resilient pressure of said spring holding the crucible in sealing contact with the mold.

As the apparatus is designed for use with (Hf-1 ferent molds requiring dliferent quantities of molten metal for filling the same, it is essential to provide means for balancing the structure. For this purpose, exchangeable counterweights M are placed in the end of the casing adjacent to the head f3. These are preferably annular in form constituting an abutment for the end of the spring L and the particular counterweight used is selected with respect to the weight of the mold and crucible together with its molten metal content. However, to obtain a more accurate balancing, provision is made for adjusting the counterweight .M towards or from the axis of the trunnions C and C. This, as shown, comprises a disc or head N engaging the outer end of the counterweight and centrally provided with a threaded bearing N for engaging a threaded shank N passing therethrough. The shank N has a smooth portion N passing outward through a central aperture in the head G and provided at its outer end with a knob or handle N by which it may be rotated. A thrust bearing N engages the inner face of the head G and one or more guide rods N extending inward from the head G and passing through corresponding apertures in the disc N hold the latter against rotation. These guide rods also support an inner bearing N for the shank N Thus, by rotating the knob N the counterweight N may be adjusted towards or from the axis of the trunnions into a position which accurately counterbalances the parts on the opposite side of said axis.

the balancing operation the'casing and its trunnions must be free to turn in their. sup porting bearings. This necessitates detachment therefrom oi the driving mechanism and for this purpose aclutchoisarrangedbetweenthe trunnion C and. the variable speed trammission l". The purpose of the variable speed trammission is toenable the operator to regulate the speed of rotation of the centrifugal holder in accordance with the requirements for particular metals used in forming the casting. any suitable mechanism maybe usedi'or this purpos such, for instance, as the "Reeves Drive! .The details of this construction are not shown-and it will be sumcient to state that by adjusting the motor E on the base A towards or from the axis ofthe trunnions C and C, the speed of rotation of the driven member will be correspondingly reduced or increased.

The trunnions C and C are attached to the casing 13 preferably through the medium of a ring Q, which latter engages an axially tapering seat Q formed centrally on said casing. A

clamping collar Q having a screw-threaded engagement with the casing B holds the ring Q to its seat. The attachment between the ring and each of the trunnions is by a plurality of bolts Q}, the heads of which engage countersunk recesses in the inner face of the ring. The casing B is enclosed within an outer protecting casing R which, however, is cut away at the. top for access to the upper end of the casing B during loading and unloading of the same. A speedometer mechanism 8 is connected to the outer end oi the trunnion C and the indicator dial 8 thereof is arranged at a convenient point on the casing R for observation by the operator.

Operetims In the operation of the machine, the operator first selects a counterweight as suitable for counterbalancing a particular mold and crucible and places this within the casing 3 adjacent to the disc N. The spring L is then placed within the casing to abut against the counterweight M and the seat member K is placed against the upper end of the spring in positionto receive the cruelble J. The mold I is then placed within the casing against the crucible J and is pressed inward and locked into position by the cap or closure H. The operator may then accurately balance the structure by shifting the counterweight M through the rotation of the screw. threaded shank N by the knob or'handle N When balance is attained, the mold and crucible are removedfrom the casing and the latter is placed within a furnace to melt the metal which is to be cast. When the molten metal is at the desired temperature, the crucible can be quickly transferred from the furnace to the open end of the casing B and engaged with the refractory seat K. The mold I is then placed against the crucible and the cap H is locked in position. Prior to the loading operation the casing 13 has been turned into upright position by means of the handwheel P. After loading is completed the clutch O is moved by its operating lever 0 to couple the trunnion C with the transmission mechanism F. The motor is then energized to revolve the casing B and the speed of revolution of the latter is regulated to produce the desired pressure on the molten metal. Centrifugal force will throw the molten metal outward into the recess P of the mold and through the sprue 1 into the mold cavity. 7 The work is removed from the casing B by turning the casing into upright v 4 position'andremoving capH. The and crucible may then be removed and th paratus is in condition for' repeating mold e D- operation with another mold and crucible.

What we claim as ourinvention is: r i. In a centrifugal casting machine, a cylin-' drical casing mounted for revolution in a vertical plane about a central transverse axis, a heated crucible with molten content and a mold b'oth insertable within said casing when in upisht position through anopen upper end there.,.

said annular memberand holding the same on one side of the axis of rotation of said casing, and a closure for the open end of said casing adapted to press said mold into sealing contact with said crucible against the resilient pressure of said spring.

2. In a centrifugal casting machine, a cylindrical casing mounted for revolution in a vertical plane about a central transverse axis, a heated crucible with moltencontent and a mold both insertable within said casing when in upright position through an open upper end thereof the mold being inverted above and seated upon the top rim of said crucible, an annular member slidable within said casing and provided with a refractory lining forming a seat for said crucible, a helical spring coaxially arranged within said casing forming a resilient support for said annular member and holding the same. on one side of the axis of rotation of said casing, a'closure for the open upper endof said casing adapted to press said mold into sealing contact with said crucible against the resilient pressure oi said spring, and an annular exchangeable counterweight within said casing forming an abutment for said spring on the opposite side oi said axis of rotation.

3. In a centrifugal casting machine, a cylindrical casing, a trunnion projecting laterally from the central portion of said casing, a hearing in which said trunnion is iournaled, a detachable closure for one end of said casing, a heated crucible with molten content and a mold both insertable within said casing when in upright position with the closure removed the mold being inverted above and seated upon the top ring of said crucible, an annular seat for said crucible slidable within said casing, a helical spring coaxially arranged within said casing forming a resilient support for said seat whereby the engagement of said closure will press said mold into sealing contact with said crucible, a counterweight within said casing on the opposite side of the axis of said trunnion, means operable from without the casing for adjusting said counterweight towards or from said'axis to balance the structure, means for rotating said trunnion and casing, and means for adjusting seated upon the top ring of said crucible, an annular seat slidable within said casing and provided with a refractory lining for engaging and supporting said heated crucible, a helical spring coaxially arranged within said said casing for -resiliently supporting said seat, an annular counterweight in the casing on the opposite side of the axis of rotation of said trunnions and forming an abutment for said spring, a head adjacent to the outer end of said annular counterweight, a screw passing through and swiveled in the end of said casing adjacent to said head and threadedly engaging the latter whereby said counterweight may be adjusted by said screw towards or from the axis of said trunnion, rotating means for one of said trunnions, a clutch between said rotating means and said trunnion, and manually operable rotating means on the other trunnion whereby said casing can be turned into upright position.

5. In a centrifugal casting machine, a cylindrical casing having an opening at one end thereof and mounted for revolution in a vertical plane about a central transverse axis, a resiliently yieldable seat within said casing movable lengthwise thereof, a closed bottom open top crucible engaging said seat with its open top facing toward the open end of said casing, a mold engaging said crucible and in communication with the open top thereof and a closure for the open end of said casing adapted to engage said mold and press the same into sealing contact with said crucible against the resilient pressure of said seat.

6. In a centrifugal casting machine, a cylindrical casing mounted for revolution in .a vertical plane about a central horizontal axis and extending substantially equidistantly on opposite sides of said central axis, one end of said cylinder being open for substantially the full diameter thereof, a removable closure for the open end of saidcasing, a head at the opposite end of said casing, a spring sleeved within said cylindrical casing and extending from said head beyond said central axis toward said open end, an annular seat slidable within said casing and abutting said spring, a closed bottom open top crucible of a diameter to be inserted through the open end of said cylinder, a mold also insertable through the open end of said casing and adapted to engage the open top of said crucible, said spring being adapted to urge said mold and crucible toward said open end when said closure is removed and means for locking said closure to said casing against the resilient pres sure of said spring.

7. In a centrifugal casting machine, a cylindrical casing having an opening at one end thereof and mounted for revolution in a vertical plane about a central transverse axis, a resiliently yieldable seat within said casing movable lengthwise thereof, a closed bottom open top crucible engaging said seat with its open top facing toward the open end of said casing, a mold engaging said crucible and in communication with the open top thereof, a closure for the open end of said casing adapted to engage said mold and press the same into sealing contact with said crucible against the resilient pressure of said seat, an exchangeable counterweight within said casing on the opposite side of said central axis from said closure, and means operable from outside said casing for adjusting said counterweight towards or from said central axis.

8. In a centrifugal casting machine, a cylindrical casing mounted for revolution in a vertical plane about a central transverse axis, said casing being adjustable to a position in which its longitudinal axis is vertical, one end of said cylindrical casing being open for substantially the full diameter thereof, a removable closure for the open end of said casing, a closed bottom open top crucible of a. size to be inserted through said open end when said casing is in its Vertical position with said open end upward, a refractory seat slidable within said casing for receiving said crucible, resilient yieldable supporting means for said seat, a mold insertable through the open end of said casing and adapted to rest on the open top of said crucible, said closure being engageable with the upper end of said mold to press the same and said crucible against said resilient supporting means, interlocking means between said closure and said casing, an exchangeable counterweight within said casing on the opposite side of said central axis from said mold, and means operable from outside said casing for adjusting said counterweight to counterbalance the load.

RODNEY E. CHRISTIAN. ALFRED W. WIDERSTEDT.

REFERENCES (JITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,009,489 Fritzsche July 30, 1935 2,235,443 Steinbock et al. Mar. 18, 1941

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