US1767351A - Method of and means for investing denture models and patterns - Google Patents

Description

June 24, 1930. E. E. DALTON er AL 1,767,351'

TTEnns IETHODOF AND IEANS FOR INVESTING IDENTURE MODELS AND PA Whaler/M aZZYa J' ingle v Amm] F'ld Oct. 7, 1927 June 24,1930. E. EIDAQLTQN Em 1,767,351

muon or*4 Ann mms Fon mvss'rine DFN'x-URE u'oDsLs Ann PATTERNS" Filed Oct. '7,` 1927 2 Sheets-Sheet 2 Patented June 241, 1930 UNITED STATES PATENT OFFICE .l ERNEST E. DALTON AND CHARLES J'. BINGLE, OF CHICAGO, ILLINOIS METHOD OF AND MEANS FOR INVESTING DENTUBE MODELS AND PATTERNS Application filed October `7, 1927. Serial No. 224,749.

This invention relates to a method of and means for investing denture models and patterns.

Heretofore in investing-models and patterns of this sort, the investmenthas been commonly painted on the model and wax patl tern. This'investment painting process has ally been a matter of guess work, produced by building up the investment by the process of painting it upon the model or pattern. More than one mix is frequently required and the matter of getting the investment well around the pattern and sprue attachments has presented a difficult problem.

Still further a casting of this sort must be relatively thin, as well understood in the art and where the investment produces a rough-.

ness which requires any considerable grinding or finishing it is not infrequent to grind through the casting or produce weakened portions or imperfections in endeavoring to produce the smoothness which is so desired.

The object of the present invention is the provision of a generally im' roved method of and means for investing enture models and patterns to produce a smoother investment, a better uniformity in the body and surfaces of the investment and an investment of greater density.

More particularly the present invention provides a boxing device and for condensing and confining the investment. The invent-ion eliminates rough surfaces on the mold and the grinding of 'the surfaces of the casting ma also be eliminated, although it isfto be un erstoodthat the casting may be ground or lfinished, if desired. Where there is any grinding or finishing itis slight and any danger of grinding through the casting or weakening same is avoided.

-of Fig. 5;

ing' cavity;

The invention expedites the investing process, eliminates -the possibility of voids or blow-holes and assures an investment which shall be uniformly of required or sufficient thickness and without guess work.

The invention is particularly applicable to the formation of metal, usually gold or aluminum castings, but it is to be understood that the invention is not limited to use in forming a casting or plate of any particular material, but may be employed wherever suitable or desired.

The invention is illustrated in the accompanying drawings, in which:

Fig. 1 is a top plan view of an illustrative castin model and pattern that may be employe in connection with the present inven- 1on; l Fig. 2 is a section takenv on the of Fig. 1;

Fig. 3 lllustrates more or less diagram-` matically the step of applying the painting investment and simultaneously vibrating the casting model and pattern to settle the investment and bring any air or other gases to the surface;

Fig. 4 illustrates more or less diagrammaticall the next step in the process; ig. 5 is a top plan view of one form of boxing 'or coninin and condensing device with substantially t e amount of the investment material which is first introduced and the casting model in place therein;

Fig. 6 is a section taken on the ine 6--6 Fig. 7 is a sectional view similar to Fig. 6 showing the boxing device substantially filled with the investment material;

Fig. 8 is a view similar to Fig. 7 showing illustratively the step in the process which follows the filling of the boxing device;

Fig. 9 is a sectional view of the invested model with the boxing device removed.

Fig. 10 is a sectional view showing the invested model centered in -a centrifugal flask or casting ring with the outer or fin-- ishing investment applied and after introducing the gold or other metal into the castl shaft lnected by wax sprue leads 12 eign material on the surfaces Fig. 11'is a plan view of the nished casting with the metal cast in the sprue openings still in place;

Fig. 12 is a sectional view taken on the line 12-12 of Fig. 11; and

Fig. 13 is a view similar to Fig. 12 after removal of the metal and connections cast in the sprue openings.

Referring to the drawings, the model designated at 5 may be of any suitable or preferred form. These models are usually made of suitable plaster-like material from the dentists impression, as well understood in the art. The particular details or material of the model, per se, form no part of the present invention. Sulliceit to say that 5 designates any suitable model, thematerial and formation of which may vary Widely.

The impressed plate 'forming surface 6 of the model 5 is provided with a wax coating 8 of a thickness corresponding substantially to the thickness of the plate or casting. This waxed coating 8 is usually painted on with a suitable brush, as well understood, although this too forms no part of the present invention and may vary widely. The wax coating forms a wax pattern for forming the plate casting cavity and a suitable wax dental pattern 9 may be provided for forming the lingual castin cavity, all as well understood in the art. n upright and preferably centrally disposed sprue 10, preferably of wax or other suitable material, is con- With the wax casting pattern for receiving, passing and distributing thegold, aluminum or other molten metal into the plate casting cavities, as well understood.

By the rst step in our process the painting investment "material is painted over the entire wax pattern, as by means of a suitable brush 14, as shown in Fig. 3. The painting process assures good,'close and uniform contact of the investment material with the entire surface of the pattern and mold, if desired, and prevents a surface irregularities or any roughness in I#the surface of the investment along the pattern, such as might be produced by oilysubstances or other forof the pattern. In painting the investment it paint the investment material well over the surface of the attern and well around the attachment of t e sprue.

The painting investment is indicated at 15 in Fig. 3 and in applyingA this painting investment 15 the model 5 is preferably vibrated simultaneously witli the ainting on of this investment. This may e done by placing the model upon a metal plate 16 and placing this plate 16 upon the projecting 18 of a motor 20, as shown in Fi 3. When the motor is started the shaft 18 will vibrate the plat@l 16 which will settle theinvestment 15 and spread and rub the same vibration is desirable to b uniforml over the surface of the wax pattern 8. bviously the motor shaft 18 may be provided with eccentric or cam means for additionally vibrating the plate 16. The

of the model with the application of the painting investment settlesy the same and brings any bubbles or gases to the surface, eliminating the possibility of voids or blow-holes and assuring a smooth casting which need not be ground or which will at least require only a minimum of grinding or finishing. By vibrating the model simultaneously with the application of the investment 15, this application need not be as slow as heretofore and by means of this and the remainder of the technique this investment 15 may be applied liberally and without regard to the amount or uniformity f the thickness thereof.

By the next step in the process the investment material 22 which may be substantially the same as the painting investment or any other desired investing material is placed in a boxing device 23 up to say a level of about 1 inch and with the boxing device 22 laid upon the plate 16 upon the motor'shaft 18 for vibrating the same, the model upon which the initial investment material has been painted at is placed in the boxing device 5, as shown in Fig. 4.

The boxing device 23 is preferably of wax or other material that may be conveniently removed from the investment, as will be hereinafter pointed out. It has a closed bottom 25 provided with integral upstanding nibs 26 for engaging the flat bottom surface of the model 5 and supporting same in proper position in the boxing device 23 and raised slightly above the bottom wall 25 thereof. Upstanding marginally from the bottom wall 25 the boxin device 23 has the side walls 28 which may e rounded at 29 and flat or square at 30 to conform with the general contour of the model. It is to be understood, of course, that the particular shape or configuration of the boxing device may be varied as desired. The top ofthe boxing device is open at 32 and this open top 32 is provided with a separate removable cover 34, which is also preferably of wax or other material that may e readily removed from the investment. The cover 34 has an upright sleeve or tubular projection 35. The sleeve or tubular projection 35 ma be formed integral with the cov` er 34 and 1t defines an opening 36 for intro` ducingthe final portion of the rst investment and the upper open end 38 of the upright sleeve 35 is adapted to recei-ve a Weight or suitable closure, as will be pointed out later for additionally condensing the investment in the boxing device. Marginally the cover 34 is provided with a depending flange 39 v which, when the cover is placed on the boxing A, ly .about the model.

tinuing to settle The boxing device 23 confines and condenses -the investment material 22 and the boxing device may be vibrated upon the motor shaft with the investment material 22 up to substantially the level shown in Fig. 4 before placing the model therein. This will settle the investment and bring any lbubbles surface.' The model is'then continuing the vibration of the box the modelv is settled down into position upon the nibs 26,as shown in Fig. 6 and the investment material 23 is settled and condensed uniform- Additional investment material 22 is then introduced into the top of the box 23, the vibration upon the motor shaft 18, or in any other suitable 4manner conany gases or bubbles to the surface, as the investment is builtup in the boxing device. This produces a smooth surfaced investment and an investment having greater density and with its body and surfaces more uniform.

As the investment isbuilt up, in this` manner to or toward. the top of the box 23 the cover 34 is'placed upon the box. The upright sleeve portion 35 in addition to pro# 'viding material and for additionally condensin the same receives the sprue 10. The ladditional investment material may be then lintroduced thru the upright sleeve portion 35 up to. the top thereof, the vibration of the boxing device continuing to settle the investment and bring any bubbles or gases to the surface as it is introduced andto confine and condense the same uniformly and densely about the model.

When the boxing device has been filled up to the top of the tubular projection 35 an additional amount of investment placed over the top of the opening 38 so that the investment will project therefrom and,

f then the investment in the boxing device may any be additionally condensed by placing a weight or closure 45 over the opening 38, as shown in Fig. 8. The closure 45 may be flexible so that it may be pressed down by the f hand to additionally condense the investment Y although material within the boxing device,

other suitable condensing application may be imparted. This substantially completes the technique and the boxing and condensing processof the present invention, and wey find that a smoother investment is produced together with a, better uniformity in the body and surfac investment is of greater density and surface w irregularities and roughness are avoided.

We nd that an exceedingly smooth' casting v .is produced and that grinding and finishing may be eliminated or where desired is slight and without danger of grinding through or vweakening; the casting. When the investment 23 has set and lhardened the wax strucvention,

the investment and bringv may bel s of the investment. The

ture of the boxing device permits this to be expeditiously and conveniently peeled off. This is another important aspect of the inalthough it `is to be understood thatl the boxing device may be of other material and it may be formed for removal from the investment without peeling it off or destroying the boxing device. In this manner the boxing device would be adapted for re-use although thisv isnot desirable and we prefer to peel it olf and destroy itafter vone use.

After the boxing device 23 is removed the investment is centered in a suitable metal flask or castin ring 50, as shown in Fig. 9 and the ring is lled with the casting or outer investment 52 AWhi'ch is then allowed to set. These casting rings are usually made of two pieces and provided with lugs 53 which lock the ring in the centrifugal casting machine,

as well understood in the art. The features of investing the investment in the ring 52 apply particularly to Wherethe denture is -Ployedfor introducing further investment After the investment 52 has set the'investment may be dried out to burn out the wax sprue 10 and connctions 12 in the usual or any suitable manner. This is frequently done by. `placing the investment on aradial burner with the sprue hole down and when the gas is turned on it burns out the Wax inlays and frees'the investment of any Water. Any other suitable or-preferred manner of removing 'the wax may, of course, be `eniployed. 1' i In centri'fugallycasting the same after the investment 52 has set and hardened suficiently the ring 50 is placedin the centrifugal casting machine vand the gold or other'` molten material is introduced through the sprue cavity 54 and'flows in and ills the casting cavities 56 and 57' andthe sprue connection cavities 55. The resulting casting is desi'gf nated at 58, it consists of the plate portion 59, l

' connectionsA 62 extended may be finished as desired.

Wherel we use the term model in the appended claims we intend it to'apply to the model and pattern and a painting of the main body of the model or the pattern portion only is tobe considered a paintingof the model. f L

We also intend'the term model to cover any dental model or pattern Whether for a complete or partial denture, an inlay or 'anyoral restoration.

inl

, ing an open top and a cover removably fitting the top of said box and provided with a tubular projection opening into the interior of the box, said boxing device being formed of a material that may be peeled off 'of the investment.

3. As an article of manufacture, a boxing device formed to receive a denture model, said boxing device being adapted to confine the investing material upon the model and of a material which may be peeled off of the investment..

4. As an article of manufacture, a boxing device for dental investment formed of wax and adapted to receive and confine the investment upon the model.

5. As an article of manufacture, a boxing device for dental investment comprising a box having an open top and a removable cover having a depending marginal flange adapted to lit over the upper marginal edge of said box and having a tubular wax projection opening into the box.

6. As an article of manufacture, a dental boxing device includin a box part and a cover part and rovidelwith a tubular projection on one o said parts and openingl into the interior of the boxing device.

an article of manufacture, a dental boxing device adapted to receive investment material and a dental model for molding and confining the investment material upon the model and means within said boxing device and independent of the investment material for spacing the model from the bottom of the boxing` device.

8. As an article of manufacture, a dental boxing device adapted to receive investment material.. and a dental model for molding and confining the investment material upon the model and means within said boxing device and independent of the investment material for spacing the model from the bottom of the boxing device, said means comprising upstanding nibs on the interior of the bottom Wall of the boxingy device.

9. As an article of manufacture, a dental boxing device formed of receive investment material and' a dental model for molding and confining the investment material upon the model and integral wax nibs on the interior of the bottom wall of wax and adapted to- 11. A boxing device comprising a box formed to receive a denture model and having an open side and ting the open side of said box, said closure having an opening providing communication from the exterior of said box into the interior of the box.

12. As an article of manufacture, a noxing device cover comprising a closure portion and a tubular projection formed integrally 'of Wax.

In Witness whereof, We hereunto subscribe our names this 3rd day of October, 1927.

' ERNEST E. DALTON. CHARLES J. RINGLE.

a closure removably itv

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