US2257861A - Dentist's casting machine - Google Patents

Description

H. H. SAMUELS 2,257,861

DENTISTS CASTING MACHINE Oct. 7, 1941.

2 Sheets-Sheet 1 Filed July 8, 1940 m-ma; :3

INVENTOR ATTORNEYS WITNESS Oct. 7, '1941. H. H. SAMUELS 2,257,851

DENTISTS CASTING- MACHINE Filed July 8, l940 2 Sheets-Sheet 2 I 15 J d1 10 (3.2 1 76 16 Q I J 2% O INVENTOR ATTORN EYS WITNESS Patented Oct. 7, 194i DENTISTS CASTING MACHINE 1 Henry H. Samucls, Rustenburg, Transvaal,

Union of South Africa Application July 8, 1940, Serial No. 344,408 In Union of South Africa June 30, 1939 1 Claim.

This invention relates to improvements in casting machines and especially is concerned with a novel device useful in the casting of dental inlays, in'casements, fillers, plates and the like.

Because the noble metals are especially resistant to corrosion and hence unaffected by oral conditions, and because gold is both the cheapest and the most commonly available of the noble metals, it is presently the practice to manufacture inlays, fillers, plates and other oral structures from gold usually by casting and it is devices useful for this purpose that thepresent invention is directed. 7

Experience indicates that in the casting of gold in molds having minute fissures, it is desirable that during the casting operation intermediate the pouring and solidification of the metal being cast positive pressure be applied to assure penetration of the fissures by the metal. I In the past this has been accomplished by application of Snperatmospheric pressure to the melted metal while within the mold. This practice, however, has necessitated the use of relatively complicated and consequently expensive equipment with resultant expense which is made unnecessary by practice of the present invention.

- It is an object of the present invention toprovide means for materially increasing the pressure applied to molten metal within a mold resulting from heat exchange between superheated metal and adjoining materials whereby the metal is compressed within the mold assuring faithful reproduction of the mold outline.

Another object of this invention is to provide a convenient machine useful in the casting of gold inlays and the like which includes means both forcing the metal into minute fissures and which also serves to preclude or at least minimize loss of gold due to splattering while the gold is transferred into the mold.

Noteworthy among the advantageous features of the present invention are its simplicity and ruggedness of construction, the former suiting the device to the requirements of manufacture under conditions of mass production and the latter assuring long useful life.

Other objects and features of the newand improved dentists casting machine according to the present invention will be apparent to those skilled in this art during the course of the following description. 7

Regarded in certain of its broaderaspects the novel casting machine according to the present invention comprises a base where'on'a casting ring can be rigidly mounted, a vertically reciprocable cap, for said ring carried in a frame attached to said base, and means for facilitating the packing of said cap with moist melted fibrous material whereby, when said cap is pressed upon the casting ring, radiant heat of molten metal Within the casting ring causes vaporization of moisture in the matted fibrous material and the steam so produced forces the molten metal into minute interstices of the mold, the pressure continuing until the metal has solidified.

In order to facilitate a fuller and'more complete understanding of the present invention a specific embodiment thereof herein illustrated will be hereinafter described, it being clearly understood, however, that the illustrated embodiment, although presently preferred, is provided solely by way of example of the practice of this invention and not by way of limitation thereof except insofar as the invention is recited in the subjoined claim,

Referring then to the drawings,

Figure 1 is substantially a side elevational view of the presently preferred embodiment of this invention,

Fig; 2 is a top plan in Fig. 1, 1

Fig. 3 is essentially a vertical sectional view of Fig 1 taken along the line 3-3 thereof,

5 Fig. 4'is essentially a horizontal sectional view of Fig. 1 taken along the line 4-4 thereof, a

Fig. 5 is substantially a perspective view of the vertically sliding carriage forming part of the device illustrated in Fig. 1,

Fig. 6 is essentially a side elevational view of the vertically sliding carriage showing a stirrup clamp mounted thereon for forming a fibrous mat in parts of the device as will be subsequently described,

Fig. 7 is'ess'entially a front elevational view of the assembly shown in Fig; 6, and

Fig. 8 is a side elevational view of the device partially in vertical section illustrating the disposition of parts of the device while in use.

Referring now to the drawings wherein the presently preferred herein illustrated embodiment of this invention is generally designated by the reference character I0, it will be seen that the device comprises a base ll supported on feet I2 disposed essentially in a horizontal plane and having a flat top surface from which extend essentially parallel guide bars l3 rigidly secured in the base by appropriate means such as threading or the like. A carriage l4 having fixedly mounted therein split sleeves l5 exteriorly taperthreaded to receive rings I6 is mounted upon the standards l3, the rings and sleeves serving upon occasion to permit the holding of the carriage in a selected position with respect to the base. A lever I'l swinging upon an adjustable fulcrum which comprises a pin l8 receivable in any one of a plurality of openings l9 formed in an upview of the device shown right member 20 mounted upon the base II 'by' means of screws 22 is connected to the carriage [4 by means of ball and socket joints generally designated by the reference characters 23 and carried on a pin rigidly mounted on a central portion of the carriage M. For purposes whichwill be hereinafter described posts 3| are provided near the corners of the carriage M, the posts projecting upwardly from the surface of the carriage to a degree such that whenthe carriage is inverted the ball 29 carried on-the pin 30* will clear a surface upon which the inverted;'car-.

ing sleeve 32 is threaded into an opening formed in the under side of the carriage l4.

A plurality of perforations V I la formed in the basell are arranged concentric the axis of the sleeve 32 and lQ l itudinally slidingclamps 33, 34 and 35 having V-shaped clampingend; portions are mounted upon the base l l in a manner facilitating the gripping of a casting ring; therebetween substantially as shown in Fig. 8. The clamps 33 and 34 it will be noted can be held in position by wing nuts 36 and 31 respectively and the clamp element 35 can be held in position or adjusted as the case may be by means of a screw 38 receivable within parts of' the base H. A sliding guide member 35a is providedto prevent rotation of the clamp element during adjustment of the screw 38. 7,

Referring now particularly to Figs. 6 and '7 it will be noticed that trunnions 39 extending outwardly from sides of the carriage l4 receive hook elements 40 formed in end portions of a stirrup frame 4| which hangs downwardly from the carriage substantially as illustrated, A screw 62 manually operable by means of a wheel 42a carries on its upper end a cup 3 adapted to receive the bottom end portion of the-internally upwardly tapered sleeve 32 hereinabove described. It is to be notedthat the interior of the cup includes a centrallylocatedupstanding bump which projects into the open end of the sleeve for purposes which will hereinafter be described. The well portion 43b of the cup; 43 is spaced with respect to the sides of the sleeve 3?. and terminates at its base in a trough 43c communicating withthe interior of the cup by radially extending openings formed near thebase of the cup walls. v

Having described the structural. features of the novel castingmachine according to the present invention its preferred mode of operation next will be described during the course of which reference will be made to. the numbered parts of the figures of the drawings and particularly to Fig. 8. Assuming the device assembled as described, a first step in use is disengagement of the link 25 from the joint 24 whereby the lever arm I! can be raised upwardly and backwardly and the carriage I4 removed from the standards I3. The carriage is inverted and placed upon a suitable support and wet fibrous material such asasbestos or the like is pressed within the sleeve 32 by means of a pestle or similar appropriate tool causing the matted fibrous material to be distributed within the sleeve. and across the mouth thereof substantially as shown in Fig. 8 wherein the main body of the fibrous material within thesleeve 32 is designated by the reference character A and the matted ma-1 terial around the mouth of the sleeve by the reference character A. It is to be noted that a cavity A is formed in the surface of the matted fiber for purposes which hereinafter will be more fully described.

When the matted fibrous material has been so disposed within the sleeve final pressing is accomplished preferably by use of the stirrup frame and cup illustrated in Figs. 6 and '7. In this instance appropriate quantities of wet fibrous materialif necessary are placed within the cup 43 and: the cup advanced against the open bottom end. 0f; the, sleeve 32 by rotation of the screw 42. riage is placed. An upwardly internally taper- It is to. be noted that moisture pressed from the fiberwill now collect in the trough 430 from edge portions of the cup 43 thereby preventing overflow of moisture onto the base of the device when the final pressing takes place after the carriage l4 has been returned to its position upon: the standard l3. 7

Assuming thematted material has been pressed within the sleeve 32 as described and a casting ring B having a mold C formed in an investment D withinsaid ring is held in the sliding clamps 33, 3d, and 35 above described, the carriage is moved downwardly by manipulation of the lever I! after connection of the link 25 with the joint 24 whereby the bottom of the sleeve 32 registers with and closes the open top'of thecasting ring B. In this manner the moisture matted fibrous material A is brought in close'proximity to superheated metal located-in the inverted conical cavity formed in the top of the investment and, inasmuch as asealed; chamber is provided by engagement of the sleeve endwith thecasting ring, moisture vaporized from the matted fiber produces steam which forces the molten metal into the mold cavity C causing complete penetration of the interstices thereof and assuring faithful reproduction in the molded object of the contour of the mold. It is preferred that the pressure appliedby means of the lever ll be continued until the molded metal bas hardened.

It is to beunderstood that this invention is capable ofextended application and is not confined" to the precise illustrated forms nor described construction and, therefore, such changes and modifications may be; made therein as do not affect the spirit of the-invention nor exceed the scope of the appended. claim.

Having thus described the present invention, what. it is desired to secure by Letters Patent is:

A device for casting dental inlays, comprising a fiat base havinga central. foraminous portion; two oppositely arranged uprights carried bythe base on the outside of. the foraminous portion, horizontally adjustable clamping means carried by the base-for adjustably-holding a. casting ring onthe foraminous, portion of the base, a carriage vertically movable on. said uprights, means carried by the carriage for holding the same in its adjusted position on theuprights, a standard carriedby the base beyond the uprights, a lever pivotally connected to the standard and straddling; the uprights, alink interposed between the carriage and the lever and having ball and socket connectionswith; the; same, a' tapering sleeve mountedon the,;underside of the carriage adapted to form. sealing engagement with a-casting ringheldon:saidnbasek r I HENRY H. sAMUnLs.

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