US2147103A - Apparatus for investing and casting inlays - Google Patents

Description

' Feb. 14, 1939. 'v-- W v 2,147,103

I APPARATUS FOR INVESTING AND CASTING INLAYS Filed Feb, 5, 1937 '-2 Sheets-Shegt-l BY ATTORNEY Feb. 14,1939. E 2,147,103

APPARATUS FOR INVESTING AND CASTING INLAYS Filed Feb. 5, 1957 I 2 Sheets-Sheet 2 ATTORNEY l Patented Feb; 14,1939

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My "invention relates to "a processjandapparatus forJinvesting andicasting-dentalinlaysf An ob jectof my' invention is to provide means l iorlapplyingithe'jinvesting materlal aboutwax I denturei formations byJal uniform and maximum centrifugalaction. l I I l-Aufurther object of my'invention is toprovide means' for such investing fsoas-to provide a closely homogeneously invested mass, with all of the air 10. pockets "andf-the' moisture properly excluded therefrom'by'such centrifugal action? l V A further object of myfinventi'onis.to provide any electrical apparatus: which will apply such centrifugal action atithe proper rate and-which can be conveniently controllediu- .ja-.'A"further object of my inventi'ontis. to provide meansv forcasting inlays from;-.gold,-.gusing the I sameapparatus which is'used. for the investing Drocessj.

A 'further obj'ect of my 'inventionis'to provide adjustable 'meansto" cast .such gold: centrifugally,

' and to l-s'upplyzthe maximumqamount of.:centrif.'

' inlay. I

A'afurtheriobject of'my inventionis t o provide identical? means for investing iandi-casting in a.

device-which readily a'ccommodates itself :tovthe centrifugally thrown position.

Afurther. object of my invention is 'toprovide 3Q; a'rotating support which=rotates horizontallyand ause'san electric-motor'forfthe most efllcient oper ation; and whichrotatirlg sup'portincl'udesmeans for: regulating the balanced length of either the investing or .the casting methods. -22,

v A further object or my inventionlisto provide the above Lmentioned characteristicsf in a 'con-' struction which is" reasona'ble in cost oflkmanu fa'ctureb 'With theserxand-otherobjects. in' View, myinvention consists 'in"the construction, arrangement" andxcombination of "the various parts of my; de-

vice,. w'hereby'the objectscontemplated are; at tainedgas hereinafter more fullyset forth, point" ed out in my claim; and illustrated in theaccom s pariying adrawingspinwhich: v

. -Figure '11 isla'side elevation oizthe apparatus used .forl centrifugally.v investirignnd' c asting the ra ure-es is-a ironti vievvt ofathmcentrifugally thrown.;receiving cup; i; 1

' gFigurieA is a sectionalvlewof the investinglcup I together/with the inlay-receiving member, 1 l f -Figure 5iis 1a sectional YiQW-z'ShOWiIlg the gold inlays just. before Iormat1on thereof,:f r

threaded integirl extension 23.

Figure 6; is' an elevation of the" machlnefshow ing the position, of themembers during the investm Qperatiomand- Figure Tis'a correspondingyiew' showing the casting operation. I

tis highly essential in the'formationof dental inlays,- first that tlie'packing of the investing material about the preliminary wax impressions be as close and-as"hoinogeneous as possible to eliminate air pockets orb moisture pockets? His 10 also extremely important that the gold inlay whi'chis made'in the-holl'ow-fiiold, beof maximum concentration and density 'and that the same be made1with-sharply'tdefined *formation' so that it '-:---I will proceed to showfin 'my invention-that' both of these results can be'obtained in the same identical' machine without'resorting to a great deal of unncessary labor. Furthermorefin order to provid the proper closely packed investment, as well 20 as the inlay, I use the principle of centrifugal force; properly applied; to achieve this result. a In order to obtain the maximum efiect desired; I useanelectric motor for the purpose; Ihave'used tha character III to designate generally an-eleci '5 tric motor which is positioned 'verticallyand'in cludesthe usual upwardly =ektending"vertical i 'shaft ll." 'I-he motor 40 is attached 'to the -base I2; and the electric cord connection is shown at I I3 passing iritof-thebasein the usual manner. 1 l A'rheostat is providedat -14, having three posithe cylindricalvertical member l8, and the round head machine-screw la provides means for tightening the member l8 against the shaft H. Pass- 5 7 ing through the member 'IB- at 2I -is the rod'Zll, Which- -is retained against--slidable m'otion by means of; the wing nut 22, which includes the A cylindrical balancing weight- 24 'slidably receives the rod 20 0' and is locked therewith by means ot the machine screwv25: 'JI'heend of the rod 20 is threaded,-as at i ,26, whichthreadedportiori receives-thesquarenut. -21; which nut serves to help maintain the locked positioni oi the weight. n :The forward: end .of :the' 51 rodfis; threadedsasraatg-28; and loosely engaged' therewith-tiszthe bracket 29 having the arcuate side arms 30; A nut is provided at 3|, which bears against a suitable washer 32, and 'a. further retainingamemberlgis vprovided at .33; Suflicient o spaceis left between I the. member a 33 I and the washer 32'so' that the bracket 29 is free to pivot? in .a-vertical planein either-direction," as indicated 'by'th atarrows fl in fi'giirej li.Suspended-from the-outer ends of theflarms '30 is-the' pair or "an-1740s.

ceived at 31 within the ends 35. The engagement 38, which are bent over and which are reat 31 is fairly loose for the reasons to be given.

Attached between the lower ends of the members 33, at 33, is the horizontal member 33 which The first operation necessary in' formin g'the inlay is to take the wax impression which is formed in the necessary shape desired; and pack the investing material closelyabout the same. It..; is'also extremely important to force out all moisture within such investing material.

I have used the character 43 to represent the i cylindrical investing-receiving membeng which 111- cludes a further asbestos or other liner 44, which is also cylindrical. The investing cup is indicated by .the'character 45, which includes the substantiallyarcuate sides and the lowerportion 41, which is slightly beveled to fltwithin the upper portionof the member 43. ,Asmall opening is provided at in the bottom, of the investing cup. .A further member 50 isprovided,

- having the conical-formation 5| into which is pressed a substantial amount of wax 52. A series of pins 53 which are attached. to the wax formations 54, are forced through thewax 52 with their outer'ends extending s i htlyabovethe surface pfthe wax asshownin Figures 4 and :6. The member 50 includes the upturned annular flange 55, which snugly receives the member 43 at the bottom thereof. I I

After the wax impressionsare formed to the V suitable shape desired,- they are fixed in'the member 50 asexplained and the member 50 is Vattached to the member 43 through the. medium of the flange 55. ;The investing material is then formed. e r v The investing materialis usually a plaster substance which is.mixed. with,water, and the necessary amount is then packed into the upper cup 45 as shown inFigure 4. Themember 43, which then carries the member 50, as well as the cup 45, is then placed within the cylindrical cup 40 in themachine. Since the combined weight of the; investing material together with the other members is heavier thanin the casting process, the rod 20 can be moved until it abuts .against the pin, 4 I when the wing nut isagain tightened.

This-throws the weight 24 farther outward with respect to themachine, providing the proper balance. I i

i'l'he rheostat control 'isrthen thrownover to the position at, l5,which is the slow speed position, since ,I have found that the best investing, speed is about 1200 R. P. M. The motor then" rotates atlthis speed, and during such rotation the plastic investing material, which Ihave indicated by the character 55, is uniformlyand efflciently thrown through the opening 43.

Figure 6 shows the position of the various mem-;

bers during the centrifugal action jimparted thereto, andthe cylindrical member 40-, carrying the-various members, 'will'lie'directlyin a'horivaontal axis.

The machine-is allowed to run.for a certain length of time and after all of the investing material 56 1s thrown through the opening 48, it is then surrounding thewax impressions 54. During: the continued motion .of the motor,-the centrifugal action imp rted tends to paclrlthe in-' material ll very closely about the-1m terial and all of such unnecessary elements are thus completely removed from the investing material.

i "The centrifugal proces s impartedby the electric' motor, packs the investing material so closely about the wax impressions that there are no air pockets formed, which is highly essential for perfect casting.

The excess liquid within the member 40 is easily removed bypivoting the member 40 upwardly,

allowing the" same to fallout by gravity.

After this process the machine is stopped and the cup 43, carrying the attendant members, is removed from the member 40.

Next, thecup 45 is removed from the member 43 and then the pins'53 are pulled out of the wax and the investing material 55, which is now in the lower member .43. The member 50 is then pulled out, leaving the conical opening. This operation, of course, is performed after the substance 56 has set properly, which can be hastened in any manner-wellknown in the art. The resultantstructure is as shown inFigure 5, and the member 43 is-reversed as shown in thisflgure. There are now provided a series of openings 58, which were formerly occupied by the .pins 53. The member 43 is then suitably heated until the wax impressions 54 are completely evaporated through the openings 58. l The device is. now ready for; the gold-inlay forming operation; -'I'he member 43, containing the paster. 55, is now heated to a-fairly substantial degree to maintain the temperature within the casting openings. Asolid gold piece, such as 59,.is now placed within the 'lower portion of the cone 5! and directly above the openings. 53. The gold 59 is heated by means of a blow torch, or any other well known means, until it reaches the melting point, and-after a sufficient heat is applied to maintainthe same in a fluid condition for the necessary interval,the arrangement is then again put into the cylindrical cup 40, and the rheostat controlis thrown over to the position It, which -is thehigher speed position, and which ranges from approximately 2000 to 2400 R. P. M. During such centrifugal action, the fluid gold is thrown into theopenings- 58' and thence inwardly into the hollow cores formed by the removal of the wax impressions 54. I

During the centrifugal action, the gold is closelypacked with a maximum effect so that sharp impressions are formed, providing flawless inlays. After preliminary cooling, the substance 56 is removed together with the inner lining member 44, and the material is broken away about the dentures. The excess gold is scraped off close to the dentures, which gold canbe remelted and draw the metal awayfrom the walls of thecavities, etc. "By the application of the undiminished and constant centrifugal force, however, during such 'contraction the gold is still being forced against-the outlines of the hollow gold sothat in spite of.contraction, a-perfectly'formed denture is obtained.

During the casting'operatiomsince the weight a of the member 43 is lightened, the rod 2|! is passed, I 10 left, throws the weight 24 inwardly thereby again effecting the proper balance between theweight ,and the processed material andattachments.

through the member l8 u ntil thepin 42 abuts thereagainst. This movement of'the rod to the From observation of Figure 3, it will be noted that beforethe machine attains full speed, the

pivoting action about the rod 20,-as'indicated by the arrows 34, allows the material to be gradually carried into the functioning position without any tendency of spilling or abrupt jerks, which would be present if: the connection were'madefrigid, "I'he pivotal connection described'compensates for this and insures a uniform action: I

It will now be seenthat- I have provided, a proc ess and apparatus for investing and casting inlays which employs means forusing a uniform and [maximum centrifugal action, which provides" 1 II means for investing whichinsures'a closely packed investing mass with all air pockets and-moistureg excluded, which is electrically driven to insure the most eflicient results, which employs" an identical device for both investing and casting inlays by centrifugal action, which during'the gold cast- "in'gxoperation insures the immediate passage of the molten gold to thefldenture pocket, thereby eliminating heat losses, whichincludesmeans for readily attaining desired adjustments in the machine, and that I have provided a structure which 1 is simply constructed. j 1

Some changes may be made in the construction and arrangement of the parts of my invention without departing from the real spirit and purpose of my invention, and it is my intention to cover, by my claim any modified forms of structure or use of mechanical equivalents, which may bereasonablyincluded within their scope.

I 'I'c'laimas myinvention:

Anapparatus' for investing and casting inlays comprising an electric motor, an arm attached transversely to the motor shaft, a receiving member attached at one-end of said arm, means receivable inysaid receiving member for causing centrifugal action to imparted to investing or I casting material, including a wax form receiving member, a cup containing plastic investing material engaged with said member said cup including a bottom having an opening for causing said investing material to be thrown therethrough and about the .wax forms by; such centrifugal action, a conical memberfor securingvwax formsseparably attached to said receiving member, re-

moval of said conical mem'ber causing a conical depression to be formed in the investing material throwninto said .receivingmember, said conicali depression adapted to receive a molten metal, said conical member including wax impressedthereon, pins passing through the wax andattached to said wax forms, removal of said pins forming hollow' passageways for transferring said molten metal to the hollow cavities formed by evaporation of the wax forms, said transverse I arm including a counter-weight attached thereto,

meansfor regulating balanced adjustment of said arm, including pins attached to the arm at established points regulating proper balancing for 1 either, investing or casting operation.

DALE L. mm. I

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