US2636232A

US2636232A - Centrifugal casting machine

Info

Publication number: US2636232A
Application number: US751655A
Authority: US
Inventors: Jr John Frei
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-06-02
Filing date: 1947-06-02
Publication date: 1953-04-28
Anticipated expiration: 1970-04-28

Description

J. FREI, JR

CENTRIFUGAL CASTING MACHINE April 28, 1953 2 SHEETSSHEET 2 Filed June 2, 1947 & 1% N fizwerziar: Jv/m F361), Jr.

/ QQQ Patented Apr. 28, 1953 UNITED STATES PATENT OFFICE CENIRIFUGAL oAsmNo MACHINE JohnFreLJn, Chicago, Ill. Application 'Junejz, 1947, Serial No. 751,655

6 :Claims.

My invention relates to centrifugal casting of metal and more particularly to a centrifugal casting machine.

It is an object of my invention to provide a centrifugal casting machine in which the use of less centrifugal force is required than is necessary in the usual centrifugal casting machines operating about a vertical axis. A centrifugal casting machine which operates about a vertical axis generally is required to lift the metal in the crucible from a lower level to a higher level at whichthe outlet of the crucible is located, before the metal will be cast therefrom into the mold. This lifting action requires the exertion of con siderable force and that necessitates higher angular velocities. More time may also be required to complete the casting operation. In the accomplishment of the above mentioned object I provide a centrifugal casting machine which is arranged to rotate about a'horizontal axis with the mold and crucible initially being vertically aligned and wherein the outlet of the crucible extends vertically and the mold is positioned radially beyond said outlet in casting relationship. "In

such arrangement the first half revolution of the I casting machine delivers the molten metal in the crucible to the mold and therefore speeds up the casting operation. Only sufficient centrifugal force need thereafter be provided to retain the metal in the mold until it has set.

It is a further advantage of my invention, wherein I dispose the centrifugal casting apparatus on a horizontal axis-that access maybe had more readily to all portions of the casting apparatus than is possible when it is disposed about a vertical axis. It is still a further advantage that the centrifugal casting machine of my invention requires far less floor space than that occupied by centrifugal casting machines of known types.

It is another object of my invention to provide a centrifugal casting machine which is adapted to accommodate molds of different sizes-withoutthe necessity of providing different sizes of cradles for holding the different sizes of molds. No special adjustments or extra parts are necessary at any time to accommodate molds of various sizes.

it is another object of my invention to provide, in conjunction with the centrifugal casting machine, heating means which will heat the metal in "the crucible to high temperatures rapidly and with a minimum of heat transference to adjacent objects. In the casting machine of my invention the heating means is so disposed relative to the rotatable apparatus of the casting machine that immediately after the metal in, the crucible is heated to the desired temperatureit can be cast into "the mold centrifugally so that there is no delay occasioned which will chill the ,metal,,o.r which will chill the mold when a pro-heated mold is-employed.

It is another object of :my inventionto pro vide sa iety means for the centrifugal casting machine of my inventionwhereby, during the casting operation, the rotating mechanism is entirely enclosed. In this connection I preferably employ a movable closure member which, when it has been moved :to cover the open side of the casting apparatus adjacent the operator, automatically starts the driving :means for the r0 tatahle apparatus of said casting machine. Also, when it is desired to cease {the casting operation, movement of the closure element away from the frontof the rotatable apparatus automatically shuts off the driving means for said apparatus.

It is a further advantage of my invention that, following the casting operation, movement of the crucible away from the mold to release the same from its casting position simultaneously returns the crucible to the position wherein it may be heated by the heating means.

Other objects, uses and advantages of :my invention will become apparent from the following description when taken with drawings in which:

Figure 1 is a front elevation of the centrifugal casting machine of my invention'with portions broken away;

Figure 2 is a horizontal, sectional view on the line 2 2 of 21:; and

Figure 3 is a vertical, sectional view on the line 3--'3 of Figure 1 illustrating the casting machine in larger scale.- Like referenoenumerals have been employed in the several views to indicate the same or similar elements.

Referring now to Figures 1, '2 and 3 it will be seen that the centrifugal casting machine illustrated in the drawings is indicated generally by the reference numeral It. This centrifugal cast ing machine comprises a vertically extending supporting structure formed of brick and angle iron, the base, indicated generally by the refereence numeral [2, being built up of brick, and the circular or arched portion, indicated generally bythe referencenumeral i ibeing formed of brick supported by angle iron 18. It will be understood that other materials could be employed in the construction of the base I 2 and arched porthe accompanying Secured to the back of the centrifugal casting machine I9 is a stationary supporting plate I8 which has a circular opening 29. The rotatable portion of the casting machine, indicated generally by the reference numeral 22, comprises a circular rotatable plate 24 which is secured to an annular flange 26 of a ring 28. The diameter of ring 28 is such that it fits within the circular opening 29 in the back supporting plate I8 with sufficient clearance so that it may be rotatable relative to the plate I8 and find bearing support therein. On the right hand side of supporting plate I8 (see Figure 3) an annular member 39, having a groove 32, is secured to the outer side of ring 28and serves to keep the ring 28 from becoming disassociated from the plate I8.. A V-belt 34 is adapted to ride in groove 32. of the annular member 36 and to extend therefrom and about a driving pulley wheel 36 which also has a V-shaped notch 38 to accommodate the belt 34.

' Pulley wheel 36 is carried on a shaft 49 for rotation therewith. Shaft 49 is supported in

bearings

42 and 44 which are secured to the base I2 of the centrifugal casting machine In in a passageway 46 which extends through said base from its back side to its front side. At its other end, shaft 49 has keyed to it, as by key 41,. a larger pulley wheel 48 having a. V'shaped notch 59 in which a V-belt 52 is adapted to ride. Belt 52 extends from the pulley wheel 48 about a small pulley wheel 54 directly connected with the driving mechanism 56 for the rotatable portion 22 of the centrifugal casting machine [8. The driving mechanism 56 is an electric motor, but it will be apparent that other driving means may be substituted therefor. It will be observed that the large pulley wheel 48 at the front of the centrifugal casting machine has a plurality of hand grips 58 by means of which the operator may manually shift the rotatable portion 22 of the casting machine when the driving mechanism 56 is shut off. The purpose of such manual shifting of the rotatable portion 22 will be explained hereinafter.

The circular revolving plate 24 (which is driven from the driving mechanism 56 through the pulley wheel 54, belt 59, pulley wheel 48, shaft 49, pulley wheel 36, belt 34,'annul'ar member 36 and ring 28) has secured to its front face 69 a supporting structure, indicated generally by the reference numeral 62, which comprises a pair of parallel side members 66 and a transverse end wall 68 which is positioned near the periphery of the circular rotatable plate 24.

The side members 66 each have a longitudinally extending slot 19. Positioned in each slot 19 is a lug 12 which is secured to a centrally apertured platform 14, which platform serves as a holder and carriage for a crucible 16. The platform 14 is guided in its movement by the slots 19. On the outer side of each side member 66 there are a pair of idler pulley wheels I8 and 89 which serve to guide a cable 82 which is connected at one end to screw eye 84 in the top of a lug I2 and which, at its other end is connected to a spring 85 and then to a cross bar 86. The bar 86 having a handle 81 at each end interconnects the two springs 85 and their respective cables 82. Intermediate the ends of each cable 82 there is interposed, in series, a sprgcket chain 88 which is adapted to engage the teeth of a sprocket Wheel 99, carried by side member 66, the sprocket wheels on each side of the supporting structure 62 being interconnected for simultaneous rotation by a shaft 92. It will therefore be seen that movement of the cross bar 86 by the operator in a downward direction to a position indicated in Figure l by the dotted line position of the bar will result in a raising of the platform 14 to its dotted line position in Figure l. The platform 14 will by its own weight tend to descend and raise the cross bar 86 unless said bar is held in its lowered position. There is therefore provided along an edge on each side member 66 a series of downwardly inclined teeth 94 under which the cross bar 86 may be hooked. Consequently the platform 14, which serves as a carriage for the crucible '16, may be ad usted to any desired height by downward movement of the cross bar 86 followed by engagement of said bar with teeth 94. If the exact level desired for platform 74 does not position the cross bar 86 exactly in alignment with teeth 94 on the side members 66, springs connected to thecross bar 86 will permit of adjustment of the position of the cross bar so that it may engage the teeth. The advantage and purpose of this ad ustment will be pointed out at greater length hereinafter.

The purpose of employing the sprocket chains 88 and interconnected sprocket wheels 99 intermediate the ends of the respective cables 82 is to maintain the platform 14 in horizontal position and to exert equal lifting force on its opposite sides even when the force supplied to the cross bar 86 may be greater on one side than on the other. It will be seen that pulling down on one side of the cross bar 86 will cause the cable 82 connected to that side of the bar to drive the sprocket wheel 99 on that side and said sprocket wheel by being interconnected by the shaft 92 to the other sprocket wheel 99, will drive the other cable 82 at the same rate so that there will be an automatic adjustment of this unbalanced force. Consequently, the platform 14 will not be cocked from its horizontal osition, which movement might result in jamming of the platform between the side members 66 and shifting of the mold-containing flask 95 which is resting on the platform.

The central aperture 96 in the platform 14 is enlargedas at 98 in order to provide a seat for the flange of crucible 16. The crucible may be easily lifted out of the aperture 96 at anytime desired. In order to heat crucible I6 I supply in conjunction with the centrifugal casting machine heating means indicated generally by the reference numeral I99, which heating means in its preferred form comprises an induction coil I92 havin its leads I94 and I96 extending through a central aperture I96 in the rotatable plate 24. If desired, the induction coil I92 may be supported independently of the centrifugal casting machine I9 and does not rotate with the rotatable portion 22 of machine I9.

From Figure 3 it Will be seen that the cross bar 86 Whichis manually controlled by the operator may be engaged with the upper teeth 94 carried by the side members 66 so that the platform 14 is positioned immediately above the induction coil I92. This permits the crucible 16 carried by the platform 14 to be surrounded by the induction coil and to be heated, together with its contents, by said coil. When the metal in the crucible is heated to the desired temperature it may be withdrawn immediately from the induction coil I92 by pulling downwardly on the cross bar 86 since such downward movement will draw the platform 14 upwardly and carry the crucible with it. In use, a flask 95 containing a mold is positioned with ts pour ng sprue adjacent. the outlet of the assesses crucible 16 and in alignment therewith :as soon as the metal is heated to the propertemperature. At that time downward movement of the bar 86 'by the operatorcarries the crucible and-superimposed fiask upwardly to the dotted line position shown in Figure 1 wherein the'fiask isiheldnrmly in place between the end, or transverse, wall 68 of the supporting structure 52 by means of the platform M which is securedin an upper osition by positioning of the cross bar .86 beneath the teeth 94 adjacent said bar. In actual practice the bar 86 is drawn down until the platform 14 will go no farther in an upward direction andthen the cross bar "is moved downwardly stillfar'ther in order to have the springs"85 under "tension when thebar 86 is hooked under the teethlll.

During the operation of the centrifugal casting machine Ill the large pulley wheel 68 at the front of the centrifugal casting machine is rotating and might, by its handles 58, strike an operator standing-nearby. Consequently, in the preferred form of my invention I enclo e the pulley wheel 48 in a housing I It which covers-theirontof the wheel and its-sides and permits access to the handles of the wheel only at its upper side-by "means of the opening H2 in said housing Hi). The opening H2 is of sufficient size that a series of handles 58 011 the pulley wheel 48 may beengaged-by the operator, when the driving means for the centrifugal casting machine is inoperative, so as to position the rotating plate 24 with the supporting strum ture 62 extending vertically as shown in the drawings'. A mark II l on the supporting angle iron .IS atthe'top of the arched portion .I-d of casting mac'hinelmin cooperation with the pointer W on the margin of'the rotatable plate 24, :permits the operator. to, vertically align the supporting structure .52 by means of the handles 58 on the pulley wheel 48 when the driving means 55 has been shutoff.

To further protect theloperator of the centrifugal casting machine II! I providea movable door I I8, carried in. upper'and'lower slides I2!) and I22, respectively, which door or closure member may be positioned over the front of the-centrifugal castingmachineso that access may-not be had to the rotating parts during operation of the oasting machine. in the preferred formof myrinvention the --movable door has a contact button 24 at its upper left-hand corner, as viewed in Figure a which contact button engages a control button 1.2.6 of a switch .-I28. :Switch I28 governs the operation of the driving-means so and when the door lzI-fi is moved to the left, as viewed in Figure 1, to cover the rotating portions of the centrifugal castingniachine I of the-button .124 of door .I I8 willpress theoontrol button 126 of switch I28 and close-the contacts of said switch, whereupon driving means 56 is set in motion to drive the casting machine. .At the end of thepredeterminedperiod of rotation the door I I8 is moved to the right, as viewed in Figure :1 whereupon the control button 26, containing a springelement (not shown), is released and breaks the circuit by which the driving means is connected to asource of power. With the door withdrawn from iii-frontier" the rotatable portion .22 of the centrifugal casting machine i ll theoperatormaysthen vertically align the supporting structure 82 connected with the rotatable plate 24 by means of the handles 58011 the pulley wheel-.48.

The method of my inventionma-y beparried out byother apparatus than .that*-.shown, but it will be lllflddlfStOOd' from .thedescription of the particular apparatus illustrated the drawings,

6 The" centrifugal casting machine .of-my invention is particularly well adapted for repeatedrrapil casting operations and-may be advantageously employed in connection'with a furnace such as that shown in my copending application Serial No; 743,745,;fi1ed April "25, 1947, wherein heated flasks are continuously delivered at a desired rate for transfer-to the centrifugal casting machinea-t the time when the metal in the crucible hasbeen heated to the desired temperature. When the flask containing the mold and the crucible containing the metal have both reached'thedesired temperature positioningthem together at "that time will result in a minimum loss of heat-from the metal and'mold and will result in a better casting, assuming the casting operation may take place as soon as the mold and crucible are posi tioned in casting relationship. The ,centrifugal casting machine of my inventionis soconstructed as to permit oasting to take place almost instantaneously" following alignment of the mold and crucible in casting relationship. This will peterter understood by a description of the'operation of my machine.

Assuming that the driving means 56 forthe centrifugal casting machine Ill is inoperative and that the door -I It is withdrawn from thefront-of therotatable portion'ifi of the casting machine, the operator will first position the supporting structure 62, which is carried bythe rotatable plate 24, in vertical alignment so that-the-pointer Ilfi on the rotatable plate 2d will be opposite the marker I It on the arched portion Id of the cast-'- ing machine. At this time the platform I4 would normally be in its lowermost position, as illustrated in Figure 1, wherein it is immediately above the induction coil I02 and the manually controlled cross bar 86 will be engaged with the upper teeth 94 whiohare carried'by the side members 66 of the supporting structure'62. Ifacrucible such as crucible I6 is notalready positioned in the central aperture 95 of the plate 14 the operator will there insert the crucible and it will then be encircled by-the'induction coil I02. The next step will be to fill the crucible with metal which is to be melted and then to start the induction coil I82 to heat the crucible-and metal containedtherein. ;At the end of a predetermined heating 'period,.or atsuch time as the operator observes thatthe metal appears to be properly heated, a preheated .fiask 9.5 containing a mold will be positioned on platform '14 .with the pour, ing sprue .of the mold positioned opposite .to and .in vertical alignment with the ,outletof crucible l6 and thelinduction coil will be.'shut-ofi. The .0131- erator will immediately grasp, the .cross bar 1861b? its handles 87 and will .pullit downwardlmflthereby raising the mold andcrucible away from the induction .coil and toward the end wall 68 orthfe supporting structure 52 so that the .fiask,9.51con taining the (mold-will be held firmly-between/said end wall 68 and theplatiorm Flt. -When-;the,-flask engagestheend wall 68 the operator will continue to draw downwardly on thecross bar 86, thereby stretching the springs 85,.and will .then hooknthe cross bar under the teeth =94 carried by the-side members 66. This movement takes but 12. second or two and immediately thereafter, the operator will move thedoor lgIj-t to the leitosviewedinsfiigvure 1 whereupon its contact button 124 depress the control button IRE :of :switch 1I2B :and

start the driving 'mechanism'fifirunctioning.' This will cause :thepulley :wheel 254 of the drlving mechanismfifi to .:rotate an'd'will causetherotat zable plater'saand v.itsoattached :supportingwstrue ,ture GIcarryingJthe mold and crucible, torotate by-reason of the driving means interposed between pulley wheel -54 and the rotatable plate 24. On the first half revolution the metal will be poured into the mold and thereafter the rotatable portion 22 of the centrifugal casting machine It) will continue to be rotated at a speed sufficient to keepth'e metal in the mold by centrifugal action until the metal has set. High speeds of rotation are unnecessary with my centrifugal casting machine since the metal is delivered very easily from the crucible to the mold. In centrifugal casting machines presently in use which operate about a vertical axis it is necessary to exert considerable force merely to lift the metal up and out of the crucible since the heated metal must be positioned below the outlet of said crucible prior to the casting operation.

After the predetermined period of rotation has ended, the operator will move the door H8 to the right, as viewed in Figure 1, whereupon the electrical circuit energizing the driving means 56 will be broken by reason of the control button lZfi of switch I28 opening contacts, of said switch. Ihe

rotating portion 22 of the casting machine Ill quickly ceases rotating and then the operator grips the handles 58 of the large pulley wheel 48 and manually causes rotation of the rotatable plate 24 and its supporting structure 62 into a position wherein pointer H6 on the rotatable a plate 24 points to the marker H4 on the stationary part of the casting machine ill, assuming that the rotatable portion 22 did not stop in such position at the end of the period of rotation. The

operator then grasps the handles of the cross bar 85 and releases said bar from teeth 94 and moves it upwardly into engagement with the upper teeth 94 as soon as a platform 14 has passed downwardly to such a position that the crucible i6 is positioned within the induction coil E02. Downward movement of the platform 14 will also bring the mold into which the metal has been cast and has set. The operator will then remove the mold and will fill the crucible with metal and then turn on the induction coil once again. Then the operations set forth above will be repeated with no time lag.

' Although heating means other than an induction coil may be employed for heating the crucible for non-ferrous metals, I find that for ferrous metals the induction coil is very satisfactory from several aspects, particularly, the ability to heat the metal to very high temperatures when the casting operationsso require, economy of opera tions and savings in time. It will be appreciated that the induction coil could be dispensed with and that the crucible '15 could be filled each time from a pouring ladle if it is not necessary to heat the metal to high temperatures. However, I prefer to employ the induction coil when ferrous metals are to be heated.

Although I have described a preferred form of my invention I do not intend to be limited thereto,'except insofar as the appended claims are so limited, since various changes and modifications will suggest themselves to others from an examination of my disclosure. I claim:

1. In a centrifugal casting machine having a vertically extending supporting structure and a member supported on said supporting structure and rotatable about a horizontal axis, the improvement which consists in having the rotatable member an apertured plate-like member, together with a radially movable platform carried on the rotatable member for carrying both the crucible and mold adjacent each other in casting relationship with the mold positioned radially outwardly of the crucible, and heating means comprising a heating coil so disposed as'to intersect the extended axis of rotation of the rotatable member andhaving its electrical leads passing through the aperture of the rotatable apertured platelike member, said radially movable platform being adapted to move the crucible and mold toward and away from said heating coil along a radius of the rotatable aperture member.

2. The improvement of claim 1 wherein the radially movable platform is aperture and is adapted to support the crucible with the main portion of the crucible extending from the platform toward the axis of rotation of said rotatable member and wherein the heating coil is an induction coil adapted to encircle said main portion of the crucible with the axes of said crucible and coil being parallel to each other.

3. In a centrifugal casting machine having a vertically extending supporting structure and driving means, the combination of a rotatable plate adapted to be driven by said driving means and to be carried by said supporting structure and having a horizontal axis of rotation, carrier means carried by the plate and rotatable therewith and adapted to support a mold and crucible adjacent each other in casting relationship with the mold positioned radially outwardly of the crucible, and heating means comprising aheating coil adapted to encircle the crucible and to melt the metal therein when the coil and crucible are in a heating position with respect to each other, said heating coil being fixedly positioned with respect to the movable carrier adjacent the center of said rotatable member, and said carrier means being movable radially on said rotatable member and adapted to support and to carry both the crucible and mold with it radially outwardly from the fixed coil at said heating position to a casting position, a door adapted to be supported by the vertically ext-ending supporting structure, said door being adapted to be movable toward and away from in front of said heating coil, said rotatable plate and said means for supporting the mold and crucible, a switch carried by the vertically extending supporting structure and governing the operation of the driving means for the rotatable plate, said switch being actuated to closed position to actuate the driving means when the door is moved to its closed position and said switch being adapted to be opened to shut off the driving'means by an opening movement of the door.

4. In a centrifugal casting machine having a driving shaft and a rotatable member driven thereby, the combination of a carrier supported on the rotatable member and adapted to support both a mold and crucible adjacent each other in pouring alignment with the mold positioned radially outwardly of the crucible, and heating means comprising a heating coil adapted to encircle the crucible and to melt the metal therein when the coil and crucible are in a heating position with respect to each other, said coil being fixed at said heating position with respect to the movable carrier at a location where the heating coil intersects the axis of rotation of the rotatable member, and said carrier being movable radially on said rotatable member and adapted to support and carry both the crucible and mold with it radially outwardly, from the fixed coil at the heating position, to a casting position when said coil and crucible 'art'separated.

5. In a centrifugal casting machine having a driving shaft and a rotatable member driven thereby, the combination of a carrier supported on the rotatable member and adapted to support both a mold and crucible adjacent each other in pouring alignment with the mold positioned radially outwardly of the crucible, and heating means comprising a heating coil adapted to encircle the crucible and to melt the metal therein when the coil and crucible are in a heating position with respect to each other, said coil being fixed at said heating position with respect to the movable carrier adjacent the center of said rotatable member, and said carrier being movable radially on said rotatable member and adapted to support and carry both the crucible and mold with it radially outwardly, from the fixed coil at the heating position, to the casting position when said coil and crucible are separated.

6. In a centrifugal casting machine having a vertically extending supporting structure and a member supported on said supporting structure and rotatable about a horizontal axis, the improvement which consists in having the rotatable member an apertured plate-like member, together with a radially movable platform carried on the rotatable member for carrying both the crucible and mold adjacent each other in cast- 'ing relationship with the mold positioned radially outwardly of the crucible, and heating means comprising a heating coil fixedly disposed adjacent the center of the rotatable member and having its electrical leads passing through the aperture of the rotatable apertured plate-like member, said radially movable platform being adapted to move the crucible and mold toward and away from said heating coil along a radius of the rotatable apertured member.

JOHN FREI, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 950,106 Jameson Feb. 22, 1910 1,498,562 Maupin June 24, 1924 1,534,952 Hobday et al Apr. 25, 1925 1,562,029 Larson et al. Nov. 17, 1925 2,086,483 Tonceda et al. July 6, 1937 2,235,443 Steinbock et al. Mar. 18. 1941 2,304,067 Anderson Dec. 8. 1942 2,348,322 Bellows May 9, 1944 2,472,246 Christian et al June 7, 1949 OTHER REFERENCES Page 49 The Iron Age, October 31, 1946.