WO1991015319A1 - Lost wax process and mould structure therefor - Google Patents

Lost wax process and mould structure therefor Download PDF

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Publication number
WO1991015319A1
WO1991015319A1 PCT/FR1990/000261 FR9000261W WO9115319A1 WO 1991015319 A1 WO1991015319 A1 WO 1991015319A1 FR 9000261 W FR9000261 W FR 9000261W WO 9115319 A1 WO9115319 A1 WO 9115319A1
Authority
WO
WIPO (PCT)
Prior art keywords
hollow
wax
casting
manifold
nurse
Prior art date
Application number
PCT/FR1990/000261
Other languages
French (fr)
Inventor
Pierre Malek
Original Assignee
Pierre Malek
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
Priority to FR8813508A priority Critical patent/FR2637518B1/en
Application filed by Pierre Malek filed Critical Pierre Malek
Publication of WO1991015319A1 publication Critical patent/WO1991015319A1/en
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=9371001&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=WO1991015319(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.

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Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61CDENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
    • A61C13/00Dental prostheses; Making same
    • A61C13/20Methods or devices for soldering, casting, moulding or melting
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22CFOUNDRY MOULDING
    • B22C9/00Moulds or cores; Moulding processes
    • B22C9/02Sand moulds or like moulds for shaped castings
    • B22C9/04Use of lost patterns
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22CFOUNDRY MOULDING
    • B22C9/00Moulds or cores; Moulding processes
    • B22C9/02Sand moulds or like moulds for shaped castings
    • B22C9/04Use of lost patterns
    • B22C9/043Removing the consumable pattern
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22CFOUNDRY MOULDING
    • B22C9/00Moulds or cores; Moulding processes
    • B22C9/08Features with respect to supply of molten metal, e.g. ingates, circular gates, skim gates
    • B22C9/088Feeder heads

Abstract

At least one calcinable structure (5) is inserted between the wax model (1) and the feeder (6) so that the wax of the model, which melts when the temperature rises, flows immediately toward the outside. The wax feed rods (4) connect the model (1) and the structure (5).

Description

 Lost wax molding process and structure

The present invention which generally relates to precision casting, whether industrial or not, aims to improve the precision of the molded object. IT DOES NOT EXCLUSIVELY REFER TO DENTISTRY, AS IT SEEMS THAT IT IS FOR THIS APPLICATION THAT IT IS MOST OF INTEREST. This molding technique has been around for a very long time; It is practiced in the industry for the manufacture of objects of small dimensions in medium series or individually.

Such a realization comprises two important elements: a model (single or multiplex) and the nurse intended to allow the molding of the part considered. The two aforementioned elements form a cluster.

The latter is generally produced in a wax; It is introduced into a hatch, then coated with a refractory product called a coating and consisting of a mixture of Si Lice, plaster, sable to which a binder is added. The two elements constituting the cluster are melted to leave a negative imprint corresponding to their shape which determines channels in which a molten metal alloy is cast, to allow the desired object to be manufactured quickly and without machining, this object being of course solid. of its casting channels. We will not go into more detail on this manufacturing process, yes, it has been well known in practice for many years. This lost wax molding process has a drawback at the time of the "grappe" merger. In fact, the ouLe is heated to the melting temperature of the wax so that the bunch liquefies and is evacuated. It is obvious that it is the mass, the casting rods and the nurse which flow first, The melted wax corresponding to the sculpted model remaining trapped in its cavity until all the melted wax corresponding to the above mentioned set is removed . There is therefore a delay in evacuating the wax constituting the model, which risks causing a boiling of the wax liable to deteriorate the internal walls of the cavity determined by the model.

Under these conditions, the surfaces and contours of the part obtained are not satisfactory, so that there is a loss of the precision of the casting.

The improvements which are the object of the present invention aim to eliminate these drawbacks, that is to say to allow to preserve intact in all cases The walls of the cavity after the evacuation of the liquefied wax .

For this purpose. The molding method according to the invention consists in providing means for first evacuating the liquefied wax forming THE MODEL FROM THE SET OF THE MOLD TO THE WELDING TEMPERATURE OF THE WAX.

In a preferred embodiment, the means for evacuating the li¬ quide wax are constituted by hollow structures made of calcinable material, the sublimation temperature of which is higher than that of the melting of the wax.

The appended drawing, given by way of example, will allow a better understanding of the invention, the characteristics which it has and the advantages which it is likely to provide: FIG. 1 i Chandelier in section The sculpted model intended for the implementation of the method according to the invention.

Fig. 2 is a section through a mold containing the elements according to the invention.

Fig. 3 is a view similar to that of FIG. 2, but after evacuation of the Liquefied wax.

Fig. 4 is a view similar to that of FIG. 3, but showing the mold after fusion of the calcinable structures.

Fig. 5 is a view similar to that of FIG. 4, but showing the mold in the inverted position for the casting of the molten metal. Fig. 6 shows the metaL cluster produced.

Fig. 7 ILLUSTRATED The part obtained after separation of the supply channels. We observe that it is strictly similar to the model in fig. 1.

Fig. 8 is a view in longitudinal section of a manifold for the implementation of the method according to the invention.

Fig. 9 is a section along IX-IX (fig. 8). Fig. 10 i Chandelier The nurse of fig. 8 provided with two plugs closing the ends.

Fig. 11 is a perspective view of a casting connector used in combination with the manifold of FIG. 8.

Fig. 12 is a perspective view of a nurse set up according to a variant.

Fig. 13 ILLUSTRATIVE PERSPECTIVE A PARTICULAR REALIZATION OF CALCINABLES. We have illustrated in fig. 1 a wax sculpture 1 produced by L'Hom¬ me de l'Art and which is intended to enable the manufacture of an armature for the production of three artificial parts.

To implement the method according to the invention, a frame 2 is used, having a tubular shape one of the ends of which is closed by a bottom 2a. In the known manner, a certain amount of refractory product 3, produced in the form of a mixture of Si Lice, plaster and sable added with a binder, is added to the chassis 2 and the model 1 is made to rest. on the Free surface of the product 3, taking care to penetrate it into the hollow parts 1a of the model.

We then place on each of the elements of the model three feeding rods 4 provided solid and made in the same wax as model 1. We then place a tubular nurse made of a calcinable or sublimable material, such as La PLASTIC MATERIAL OF THE POLYETHETAL TYPE AS IT WILL BE EXPLAINED MORE AROUND. We continue to fill the mold with refractory product, an operation called in practice "coating", then we place a wax cone 6 which terminates the casting tip 5a of the nurse 5 or an extension of it. Finally, there is a rubberized base 7 on the refractory product 3 to close the chassis 2.

The whole is placed under vacuum in order to carry out the packing of the product 3. The following operation consists in placing the illustrated assembly in an oven so as to carry out the melting of the wax. This is how the masseLotte 6 liquefies and flows as well as the feeding rods and finally the model or scuLpture 1. The melting temperature of the wax being lower than that of the sublimation of the nurse 5, this -this remains intact, its role being to allow rapid evacuation through it, that is to say, drainage, of the liquefied wax constituting the mold 1 and the feeding rods 4. As illustrated in FIG. . 4, the mold temperature is raised to a temperature such that the nurse 5 calcines and disappears purely and simply, so that it remains in the frame 2 a hollow assembly corresponding on the one hand to model 1 and on the other hand to an assembly - of channels making communicate the outside of the chassis with the said model. Turning over the mold as illustrated in fig. 5, we can practice the casting of a molten metal alloy which completely fills the cavity corresponding to the model and the supply channels, so that after unmolding, we obtain part 8 illustrated in fig. 6. After separation of its supply channels 8a, the armature 8b of FIG. 7 (which is strictly identical to model 1 in fig. 1).

The manifold 5 has been more particularly illustrated in fig. 8. IT comprises first of all a tubular body 5b from which crosswise the above-mentioned tubular end piece 5a which opens inside the bore 5c of the body 5b by a hole 5d. One of the extremities of the body 5b has an enlarged bore 5e with respect to that 5c so that several feeders 5 can be placed end to end, as illustrated in broken lines.

The bore 5c of the body 5b communicates with the outside opposite the end piece 5a by several holes 5f which are three in number in the example shown.

Finally, we observe in fig. 9 that the bore 5c of the body 5b of the nurse 5 has a flat portion 5g located opposite the holes 5f. It will be noted that the wax supply rods are forced hot in the holes 5f in order to ensure the tightness and their anchoring in the nurse. When only one nurse 5 is used, it is of course necessary to close off its two ends by means of a hermetic cap 9 to prevent the refractory product or coating 3 from penetrating inside said nurse during compaction of this product. When you want to make a framework with more than three teeth, for example at the level of the incisor-canine block, it is necessary to preform it so that it matches the morphology of the dental arch which has been illustrated by a broken line 10 in fig. 8. For this purpose, we cut for example two nurses placed end to end and we fix their curvature by immobating them Reading by means of a cast connector 11 in Y (fig. 11 ) whose branches 11a and 11b come engage around the tips 5a emerging from the two nurses 5. Thus, the deformed assembly corresponds to the morphology of the dental arch. The casting connector further comprises a leg 11c , which is connected to the mass 6, directly or by means of a tubular casting rod not shown. It is observed that between the legs 11a and 11c there is provided a solid or perforated member 11d which stiffens all of the elements, and which, moreover, plays the role of radiator to maintain a higher temperature of the rods. CASTED IN RELATION TO THIS MOLDED PART. Finally, we have illustrated in fig. 12 a manifold 12 having a cylindrical body 12a, the ends of which can be closed off by plugs 13 and which comprises one or two end pieces 12b intended to be possibly connected to tubular casting rods joining them to the mass 6. These casting rods must have, over part of their length, means of orientation or articulation produced for example in the form of an accordion bellows 14a (fig. 13), ensuring their convergence necessary for their implantation in the cone. CASTING (future massotte). The body 12a also includes several tubes 1 £ or supply rod whose free end engages in model 1. The tubes 12c can of course be replaced by solid wax rods.

In the case where it is necessary to make in a single cast an armature corresponding to a complete dental arch, we use a series of nurses 5, nested one inside the other, at least some of which are bent, each end piece tubular 5a being connected to one of the ends of an articulated casting rod 14 which is deformed so that its other end comes to end in the single casting cone (fig. 13). Thus all the above-mentioned articulated casting rods 14 converge in this casting cone.

Advantageously, a spacer 15 is used which is used to join two opposite nurses in order to maintain the desired general curvature.

It goes without saying that the fitting 11, the manifold 12 as well as its plugs 13 and the rods 14 are executed in a material similar to that provided for the manifold 5 so that they are subjected to a temperature of between 100 and 200 ° C.

To facilitate cooling of the part itself or metal frame 8b iL it is advisable that it is located as close as possible to the walls of the mold. To obtain this positioning, provision is made to include either the feeding rods 4 in wax when a feeder 5 is used, or the legs 11a, 11b of the connector 11, or even the tubes 12c. from The nurse 12.

IT should also be understood that the foregoing description has been given only as an example and that it does not completely limit the scope of the invention, from which we would not be able to replace the details of execution described by all other equivaLents.

Claims

R_§_y_E_N_D_I_ £ _A_T_I_0_N_S
1. Lost wax molding process consisting of making a wax model, depositing it in a chassis, placing solid wax-cast structures in the chassis by linking them to the model, filling the chassis with refractory earth, to melt the whole in an oven to obtain, after evacuation, a cavity provided with its supply channels, characterized in that it consists in providing means for firstly evacuating the liquefied wax forming the model (1) as soon as the assembly is brought to the melting temperature of the wax.
2. Method according to claim 1, characterized in that the means for evacuating the liquid wax are constituted by hollow structures in caLcinabLe material.
3. Method according to claim 1, characterized.en that the subLimation temperature of the hollow structure is higher than the melting temperature of the wax.
4. Hollow structure allowing the implementation of the method according to claims 1, 2 and 3, characterized in that it comprises at least one manifold (5) provided on the one hand with holes for receiving supply rods (4 ) filled with wax and on the other hand with a nozzle (5a) tubular for at least one tubular casting rod made of plastic material, connecting it to a mass (6) known per se.
5. Hollow structure allowing the implementation of the process according to claims 1, 2 and 3, characterized in that it comprises a manifold (12), plugged at its two ends, comprising on the one hand supply rods of tubular casting, and on the other hand at least one end piece (12b) and a mass Masse (6) in wax known per se.
6. Hollow structure according to claim 4, characterized in that the manifold (5) is produced by means of several interlocking elements.
7. Hollow structure according to claim 6, characterized in that the manifold (5) has plugs (9) at its ends.
8. Hollow structure according to claim 7, characterized in that the feeding rods (4) filled with wax, are adjusted in the holes of the nurse while being solid of the model.
9. Hollow structure according to claim 8, characterized in that the body of the nurse (5) has a transversaLe section a annular form with inner pile ( 5g ) .
10. Hollow structure according to claim 6, characterized in that The two ends (5a) of two nurses (5) are each assembLés to the branches (11a, 11b) of a Y connector ( 11), including the leg (11c ) is a customary tubular cast rod, said immobed branches reading the curvatures of the nurses so that they respect the morphology of the dental arch (10).
11. Hollow structure according to claim 10, characterized in that a solid or perforated membrane (11d) joins the two branches C11a, 11b) of the YELLOW fitting (11).
12. Hollow structure according to claim 10, characterized in that the branches (11a, 11b) of the casting connector (11) are inclined relative to the axis of the leg (11c).
13. Hollow structure according to claim 5, characterized in that the supply tubes (12 £) are inclined relative to the axis of
The nurse (12).
14. Hollow structure according to claim 4, characterized in that it comprises a series of nipples (5) nested one inside the other, at least some of which are curved in order to cast an armature corresponding to a complete dental arch, each tubu¬ Laire endpiece (5a) of said manifolds being connected to one of the ends of an articulated neck rod (14) which is deformed so that its other end comes into the single cast cone (6).
15. Structure according to claim 14, characterized in that two nurses (5 ) of the series are joined by a spacer (15) in order to maintain the desired curvature of some of the nurses (5).
16. Structure according to the resale cation 14, characterized in that the articulation of the casting rods (14) is produced by means of an accordion-shaped souf¬ (14a) formed over part of their length.
PCT/FR1990/000261 1988-10-11 1990-04-10 Lost wax process and mould structure therefor WO1991015319A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FR8813508A FR2637518B1 (en) 1988-10-11 1988-10-11 Improved lost wax molding process and structures for implementing same

Publications (1)

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WO1991015319A1 true WO1991015319A1 (en) 1991-10-17

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ID=9371001

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FR1990/000261 WO1991015319A1 (en) 1988-10-11 1990-04-10 Lost wax process and mould structure therefor

Country Status (2)

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FR (1) FR2637518B1 (en)
WO (1) WO1991015319A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2358824A (en) * 2000-02-02 2001-08-08 Trucast Ltd Casting

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2637518B1 (en) * 1988-10-11 1990-11-30 Malek Pierre Improved lost wax molding process and structures for implementing same
WO2006121316A1 (en) * 2005-05-09 2006-11-16 Martinez Procel Jose Luis System for optimising the formation of refractory moulds for multiple metal castings in the production of fixed dental prostheses
EP2055408A1 (en) * 2007-11-01 2009-05-06 Giulio Benetti Dental prosthetic forming system

Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR386325A (en) *
US2360986A (en) * 1941-08-06 1944-10-24 Taub Francis Heat transfer in denture molds
DE1608686B1 (en) * 1961-03-30 1969-10-23 Prec Metalsmiths Inc Modelltraeger for the precise casting with Ausschmelzmodellen
US3636632A (en) * 1969-04-14 1972-01-25 Clinica Si Policlinica De Stom Method of making dental bridges, dental crowns, and dental corono-radicular retainers
DE2100667A1 (en) * 1970-01-13 1972-07-06 Cosso Luciano
US3985178A (en) * 1975-05-01 1976-10-12 Cooper Abraham J Precision investment casting apparatus with reservoir blocks
FR2495052A1 (en) * 1980-11-28 1982-06-04 Leis Gerard Machine for injection moulding prepacked dental prosthesis - to accommodate and preheat plaster moulds and prefilled cartridges
US4346750A (en) * 1979-05-25 1982-08-31 Nemethy Mike Z Method of making dental bridge using a prefabricated non-precious pontic
WO1983004198A1 (en) * 1982-06-04 1983-12-08 Rousseau Carl H Apparatus for obtaining improved dental castings
WO1985003475A1 (en) * 1984-02-10 1985-08-15 Dentifax International, Inc. Spruing assembly
WO1986000215A1 (en) * 1984-06-27 1986-01-16 Berger Robert P Prosthesis restoration molding apparatus
EP0185287A1 (en) * 1984-12-13 1986-06-25 Rudi Körner Device for casting dental prosthesis materials
US4854368A (en) * 1988-12-27 1989-08-08 Edward Vezirian Lost foam casting method
FR2637518A1 (en) * 1988-10-11 1990-04-13 Malek Pierre Improved lost-wax moulding method and structures for implementing it

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR386325A (en) *
US2360986A (en) * 1941-08-06 1944-10-24 Taub Francis Heat transfer in denture molds
DE1608686B1 (en) * 1961-03-30 1969-10-23 Prec Metalsmiths Inc Modelltraeger for the precise casting with Ausschmelzmodellen
US3636632A (en) * 1969-04-14 1972-01-25 Clinica Si Policlinica De Stom Method of making dental bridges, dental crowns, and dental corono-radicular retainers
DE2100667A1 (en) * 1970-01-13 1972-07-06 Cosso Luciano
US3985178A (en) * 1975-05-01 1976-10-12 Cooper Abraham J Precision investment casting apparatus with reservoir blocks
US4346750A (en) * 1979-05-25 1982-08-31 Nemethy Mike Z Method of making dental bridge using a prefabricated non-precious pontic
FR2495052A1 (en) * 1980-11-28 1982-06-04 Leis Gerard Machine for injection moulding prepacked dental prosthesis - to accommodate and preheat plaster moulds and prefilled cartridges
WO1983004198A1 (en) * 1982-06-04 1983-12-08 Rousseau Carl H Apparatus for obtaining improved dental castings
WO1985003475A1 (en) * 1984-02-10 1985-08-15 Dentifax International, Inc. Spruing assembly
WO1986000215A1 (en) * 1984-06-27 1986-01-16 Berger Robert P Prosthesis restoration molding apparatus
EP0185287A1 (en) * 1984-12-13 1986-06-25 Rudi Körner Device for casting dental prosthesis materials
FR2637518A1 (en) * 1988-10-11 1990-04-13 Malek Pierre Improved lost-wax moulding method and structures for implementing it
US4854368A (en) * 1988-12-27 1989-08-08 Edward Vezirian Lost foam casting method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2358824A (en) * 2000-02-02 2001-08-08 Trucast Ltd Casting

Also Published As

Publication number Publication date
FR2637518A1 (en) 1990-04-13
FR2637518B1 (en) 1990-11-30

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