CN101815592A - Apparatus for investment casting and method of investment casting - Google Patents

Abstract

Described is a method of preparing an investment casting mould, said method comprising: providing a sleeve; blocking an open end of said sleeve by fixing a water permeable material over it; and providing a water absorbent material on a side of said water permeable material opposite to said sleeve, wherein said water absorbent material is held together and constructed and arranged to ensure fluid communication between said water absorbent material and the inside of said sleeve. Also described is an object for use in removing water from an investment casting slurry in a sleeve, wherein at least a portion of an outer surface of said object is water permeable thereby to provide fluid communication from outside of said object with a water absorbent material of said object, said object comprising a sealing feature for sealing the container onto an end of a sleeve.

Description

Method and apparatus for investment casting

technical field

This invention relates to investment casting. In particular, the present invention relates to an object for removing water from an investment casting slurry within a sleeve and a method of making an investment casting mold.

Background technique

Lost wax investment casting has been used for hundreds of years. The model of the product to be produced, such as a piece of jewelry, is made of wax or similar material. The model is attached to a wax tree and placed in a sleeve such as a container or bottle. The remainder of the vessel is filled with a ceramic slurry which can then be consolidated. The wax can be melted with heat, thus leaving a mold that can be used to cast the material. Once the cast material solidifies itself, the mold is broken.

Contents of the invention

The present invention provides an object for removing water from an investment casting slurry within a sleeve, wherein at least a portion of the outer surface of the object is water permeable, thereby providing water absorption between the exterior of the object and the object In fluid communication with a non-volatile material, the object includes a sealing member for sealing the object to the end of the sleeve.

The present invention provides a container for removing water from an investment casting slurry and containing water-absorbent material, the container comprising a sealing member for removably sealing the container to an end of a sleeve, and A toothed portion that projects into the bottom of the sleeve when the sleeve is sealed to the container.

The present invention provides an object for removing water from an investment casting slurry within a sleeve, wherein at least a portion of the outer surface of the object is water permeable, thereby providing an improved connection between the exterior of the object and the interior of the object. Fluid communication of absorbent material, the object comprising a through-hole to enable the object to be placed on the protrusion such that the absorbent material surrounds the protrusion as the protrusion extends through the object.

The present invention also provides a method of preparing an investment casting mold, the method comprising: providing a sleeve; blocking the open end of the sleeve by fixing a water-permeable material on the open end; water-absorbent material is provided on a side of the material opposite the sleeve, wherein the water-absorbent material is held together and is constructed and arranged to ensure fluid communication between the water-absorbent material and the interior of the sleeve .

Description of drawings

Specific embodiments of the present invention will only be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows, in cross-section, an investment casting method not according to the present invention, generally showing how the general process works;

Fig. 2 shows the investment casting method according to the first embodiment in a sectional view;

FIG. 3 shows a cross-sectional view of an investment casting method according to a second embodiment;

FIG. 4 shows a cross-sectional view of an investment casting method according to a third embodiment;

FIG. 5 shows a cross-sectional view of an investment casting method according to a fourth embodiment;

FIG. 6 shows a cross-sectional view of an investment casting method according to a fifth embodiment;

FIG. 7 shows a cross-sectional view of an investment casting method according to a sixth embodiment;

FIG. 8 shows a cross-sectional view of an investment casting method according to a seventh embodiment;

FIG. 9 shows an investment casting method according to an eighth embodiment in a cross-sectional view;

FIG. 10 shows a cross-sectional view of an investment casting method according to a ninth embodiment;

FIG. 11 shows a cross-sectional view of an investment casting method according to a tenth embodiment;

FIG. 12 shows an investment casting method according to an eleventh embodiment in a sectional view.

Detailed ways

For the past 50 years or more, for gold, silver and copper, jewelry lost wax investment casting was cast within a molding material usually made of a mixture of silica, cristobalite and gypsum. The gypsum component is used to solidify (set) the investment casting powder slurry when casting around a wax tree. The gypsum component accomplishes this by absorbing water and thereby expanding as the gypsum crystals grow. Slurry investment casting powders must be made to flow easily so that they flow easily around the very fine wax patterns found in many jewelry, medical and industrial lost wax patterns. To make it flowable, the moisture content per 100 parts by weight of the powder needs to be between 25 and 45 parts.

For gold, silver and copper castings, the wax is usually burned out of the bottle at a temperature of 700°C plus or minus 80°C, and the metal is poured into the bottle at a temperature between 500°C and 740°C. But for investment casting of stainless steel, cobalt, platinum and expensive palladium-platinum alloys, much higher temperatures are required for dewaxing and the metal is injected into the sleeve at temperatures between 850°C and 1000°C. Higher sleeve temperatures are required to avoid chilling of high melting point metals, the metal platinum having a melting point of 1773°C compared to gold which melts at 1063°C.

Due to the higher sleeve temperatures required, gypsum can no longer be used in investment casting powder formulations because gypsum decomposes at temperatures above 800°C.

Correspondingly, for platinum, platinum alloys such as palladium/platinum, platinum-rhenium, and investment casting powder formulations for steels such as cobalt and stainless steel consist primarily of silica or a mixture of silica and cristobalite with 0.5% to 2.5% additives To solidify the investment casting powder slurry as it is poured around the wax tree inside the sleeve.

The present invention relates to mechanisms for removing water from investment casting powders that do not contain gypsum or that contain at least less than about 10% or less than about 6.0% or about 4.0% gypsum. In the absence of significant amounts of gypsum (5% to 28%) in investment casting powder slurries, water needs to be absorbed from the slurry mixture in a steadily controlled manner while the chemical additives set the silica slurry.

Figure 1 shows a technique that is commonly used worldwide for high temperature casting powders. In this method, a sleeve or bottle 10 (sleeve 10 may have any cross-sectional shape (though typically circular) and may be of any height) is placed in a water-permeable material 20 (i.e., a material that is porous to water ( such as pulp and/or other absorbent mat)). This material is between 1mm and 4mm thick. The water permeable material 20 is sealed to the bottle 10 using liquid wax 40, for example. One purpose of the water permeable material 20 is to contain the slurry in the sleeve. The wax tree 30 is glued to the center of the water-permeable material 20 with wax. This can be done before or after attaching the sleeve 10 to the water permeable material 20 . The assembly is then placed on a loose pile (10 mm to 30 mm thick) of water absorbent material 60 such as silica or gypsum or other powdered absorbent. This water-absorbing material 60 can even be the actual molding material with additives.

The liquid slurry 50 is then poured into the sleeve 50 . The slurry sets in 45 to 120 minutes. The downside is that it is very messy and tedious as the joint between the bottle and the pad has to be sealed with wax and the powder that holds the assembly has to be cleaned up and discarded. There are also physical hazards associated with the use of silica powder, as breathing fine particles of silica can cause silicosis. This problem is exacerbated in some hotter regions, where factories use fans for cooling.

The present invention avoids or alleviates at least some of the above-mentioned disadvantages by providing a method of making investment casting molds. The method includes providing a sleeve 10 . The sleeve 10 is then blocked by securing a water-permeable material to an open end thereof. Preferably, securing includes sealing. An object comprising water-absorbent material is disposed on the opposite side of the water-permeable material from the sleeve. The absorbent material is held together. For example, the absorbent material can be placed in a bag, or it can be a loose material that has been compressed, such as wood or pulp or a castable special absorbent material, specifically sized to fit into the bottom of the sleeve (eg with a circular cross-section having a diameter between 9 and 7 cm (standard diameter for sleeves is 4 to 6 inches)). Such objects of water-absorbent material may be placed in (recyclable) containers. The water-absorbent material is thus held together, eg by being compressed together and/or placed in a container. The container preferably completely surrounds said absorbent material. The container is preferably designed and/or made of a material that does not allow water-absorbing material to pass through. At least a portion of the surface of the object comprising the water-absorbent material or the wall of the container is water permeable to provide fluid communication between said water-absorbent material and the interior of the sleeve. Thus, the water-absorbent material is accommodated, so that the possibility of detachment of the water-absorbent material is reduced. Furthermore, the cleanliness of handling is improved because all absorbent materials are kept together.

If the water-absorbing material is in powder form and is contained in a container, preferably the pores or through-holes in the water-permeable portion of the container wall have a maximum diameter smaller than the average or smallest powder particle minimum diameter.

The water-absorbent material is sealed against the penetration of water prior to use, for example sealed in a water-tight package. The seal can be broken prior to use to ensure that the water-absorbent material remains unused during transport from the place of manufacture to the place of use.

Preferably the water permeable portion of the object is a water permeable material secured to one end of the sleeve. This will reduce the number of parts and can simplify the assembly of the system. For example, the invention may provide an object for removing water from an investment casting slurry within a sleeve. At least a portion of the outer surface of the object may be water permeable to provide fluid communication with the water-absorbent material of the object from the exterior of the object. The object may further comprise sealing means for sealing the container to the sleeve in a direction in which the water permeable portion contacts the investment casting slurry within the sleeve. Thus, the number of steps for manufacturing the mold is greatly reduced. To utilize such a container, a wax tree 30 with appendages 35 is simply placed over the water permeable part of the container. In one embodiment, the object includes a notch extending into the sleeve and providing a base for insertion of the trunk of the wax tree. The sleeve 10 is then placed on the wax tree 30 and sealed to the object using the object's sealing means. The sealing part of the object is preferably designed to withstand the hydrostatic pressure that occurs when the slurry 50 is poured into the sleeve 10 . This prevents water and/or slurry from escaping between the sleeve and the object before it sets. Preferably, the sealing member is constructed and arranged to be watertight to a hydrostatic pressure of water of at least 6 cm, preferably 10 cm, more preferably 15 cm and even to about 30 or 40 cm. Such an arrangement further reduces the mess associated with producing the mold and can eliminate mold cracks associated with water and/or slurry leaking around the edges.

In some embodiments the sealing member comprises a resilient material. This is a cheap and simple sealing part and has a high tolerance for different dimensions of the sleeve 10 .

The sealing member may employ a radial compressive force. This sealing feature is preferred as there is no need for any feature on the sleeve 10 to secure the container to the sleeve 10 .

In one or more embodiments, the side walls of the container are sufficiently rigid to resist pressure from the sealing member. This simplifies the design and manufacture of the body, especially when elastic and/or radially compressive sealing elements are used.

Where the object comprises a container, preferably the walls of the container (except for the water permeable part) are provided in one piece. This helps with manufacturing. For example, parts of the container other than the water-permeable part may be formed from (injection) molded plastic. In one embodiment, the fixing member is integral with the side wall of the container. The side walls of the container are generally coplanar or parallel to the side walls of the sleeve 10 . This arrangement facilitates the manufacture and assembly of the container. Additionally, this arrangement can provide sleeve 10 with additional strength and/or easy attachment.

Examples of materials for the water permeable portion include paperboard formed from wood pulp, vermiculite, perforated boards, woven materials, non-woven fabrics, and the like. A water permeability of at least 0.25 cm3/cm2/hr at a head of 0.5 cm is preferred.

The water-absorbing material described here can be, for example, silica or gypsum or other absorbent powders as described above. Other examples are wood or pulp or vermiculite. Preferably these materials have a water absorption of at least 100% by weight. Preferably the water capacity is above 110%, 120%, 130%, 150% and 200% or even more. This will provide flexibility in adapting to a given container having a sleeve 10 of a given diameter but varying height.

Seven specific implementations will be described below with reference to accompanying drawings 2-6. It should be understood that elements of one embodiment may be suitably utilized in other embodiments.

first embodiment

Fig. 2 shows a first embodiment.

The object or container or tank of the present invention may have the following characteristics:

1) Porous upper surface 85;

2) base and top (cover) and side walls that house the absorbent material 70;

3) A fixing part or sealing mechanism between the top of the absorbent container or tank 90 and the cast sleeve or bottle 10 attached to the absorbent container or tank 90 . (It may be part of the container or tank 90 or a separate part.)

4) Absorbent filler/material 70, preferably an inert non-hazardous fine grade vermiculite, but it could also be silica, gypsum, silica gel or other absorbent material, or a solid mass of absorbent material such as pulp.

The base and sides of the canister may be permeable and/or absorbent like the top, or they may be waterproof made of plastic or polymer material or similar or an absorbent core.

The amount of absorbent material in the jar (along with the absorbent capacity of the lid, sides and base of the jar) should be at least large enough to absorb unwanted water from the slurry in the jar. The higher the water absorption, the higher the setting rate of the slurry in the bottle. A water absorption of between 110% and 250% is preferred to provide flexibility in bottle height for a given diameter. Only about 60% of the water needs to be removed from the slurry in this way; the remainder of the water is removed during the burnout of the wax in the furnace.

During the solidification of the slurry in the cartridge/bottle 10, it is not necessary to remove all the water, as the remaining water (approximately 40% of the initial water capacity) can be removed during wax burnout. Sufficient moisture absorption is required to allow the slurry in the sleeve/bottle 10 to solidify, and to be strong enough so that when the sleeve/bottle 10 is placed in the furnace for burning, the solid powder around the wax tree 30 will not crumble during handling crack.

As shown in FIG. 2, a first embodiment wax tree 30 is positioned and/or secured to a water permeable material 20 (as in FIG. 1). And like in FIG. 1 , the (retrievable) sleeve 10 is placed on the wax tree 30 on the water permeable material 20 and is closed to the wax tree 30 with wax 40 . The seals are formed by a circumferential seal or wax edge or other similar sealing compound, between the sleeve and the water permeable material around the bottom end of the sleeve 10 and between the sleeve 10 and the water permeable material 20 Achieving a seal. The entire assembly is then placed on the container 90 containing the water-absorbent material 70 . At least a portion 85 of the wall 80 of the container 90 is water permeable. The water permeable portion 85 is disposed at least partially in alignment with the water permeable material 20 such that the water absorbent material 70 is in fluid communication with the sleeve 10 interior.

The sleeve 10 of the described embodiment has a circular cross section. The sleeve 10 has a standard diameter size. The cross-section need not be circular, but could be of a different shape, eg square. Also, the sleeve 10 is known as having an open top end and an open bottom end. In fact the sleeve may have a bottom end closed by a water permeable material. Also, the cross-section of the sleeve 10 may vary along the length of the sleeve. The tip can be tapered.

The shape of container 90 shown in Figure 2 is ideal. Other shapes are also suitable. For example, the manufacturing process of the container may cause seams or other joints to protrude from the container 90 . The container may for example be formed from two plates secured one above the other. In that case only the top panel is water permeable, the bottom panel may be waterproof. The slurry 50 is then added to the bottle, and the drying process begins when the water-absorbent material 70 absorbs water from the slurry 50 . Water from the slurry passes through the water permeable portion 85 and the water permeable material 20 . The outer radial shape of the container and or absorbent mass may be circular, oval, triangular, square, pentagonal, hexagonal, or different polygons.

In this embodiment, the weight of the sleeve 10 and slurry 50 holds the sleeve 10 to the container 90 .

In the embodiment of Figure 2, the portion of the wall 80 of the container 90 that does not include the water permeable portion 85 is preferably watertight. This is not required. For example the walls 80 of the container 90 may all be made of the same or similar material. That makes manufacturing easier. However, it is advantageous to ensure that the walls 80 of the container 90 which are not the water-permeable portion 85 are watertight. For example, water does not leak out of the container 90, and the possibility of water-absorbent material 70 being lost from within the container 90 once saturated with water is reduced.

The container 90 of the embodiment of Figure 2 is flexible and in use is compressed into the shape shown in Figure 2 . Transport is facilitated because the container 90 can take any shape and thus occupy a small volume. However, container 90 may be rigid, as in the other described embodiments.

The container 90 with the absorbent material 70 can be placed in a separate package. The packaging is preferably water impermeable so that the absorbent material 70 does not absorb water between manufacture and use. A single package may contain one or more containers 90 . Alternatively or additionally, different forms of sealing against ingress of water can be provided. For example a removable or breakable seal may be glued on top of the container 90 on the water permeable portion 85 . The seal can thus be removed (eg broken or peeled) prior to use.

second embodiment

Figure 3 shows a second embodiment. The second embodiment is the same as the first embodiment except as described below.

In the second embodiment, the water-permeable material 20 and the container 90 are not used. This is achieved by providing the water-absorbent material substantially in the form of a solid and/or rigid body, eg in the form of a block. That is, the water-absorbent material 70 is no longer in powder form, but has a certain shape. That is, the water-absorbent material may be shaped into an object for removing water from the investment casting slurry sleeve. The object may for example be a wood or paper (or similar material) slurry. Alternatively, the object may be made of compacted powder or fibrous absorbent material. The object does not have to be made of only one material, it can be made of layers, for example. This form of absorbent material can be used in any other embodiment. It is specifically used in the fourth to seventh embodiments. This has the advantage that other parts of the object (ie container) can be reused. As is the case with other embodiments, the absorbent material may be recyclable. That is, after the slurry is dried, the water-absorbent material that has absorbed water can be dried (for example, by heating) and then used. Preferably the body is radially elastically compressible so that the body itself acts as a sealing member for sealing the body to the end of the sleeve 10 as described below.

In the second embodiment, the object is sized and shaped to fit into the end of the sleeve 10 . The preferred body is adapted to fit snugly within the sleeve so that there is a seal between the outer surface of the body and the inner surface of the sleeve 10 . The size and shape of the object can thus be considered a sealing member for sealing the object to the sleeve such that the slurry 50 in the sleeve 10 is in fluid communication with the absorbent material.

The seal between the sleeve and the object can be accomplished using a bonded edge or wax 41 circumferentially between the object and the sleeve. Alternatively, additional components such as the sealing component of the sixth embodiment may be used. This is shown in Figure 4 described below.

However, preferably no additional components are used. The elasticity of the object itself forms the seal. That is, when not in use, the diameter of the object is larger than the inner diameter of the sleeve. When inserted into the sleeve, a compressive force is applied to the object, and the outward force generated by the compression acts between the object and the sleeve to make a seal. The shape of the object may be such that it facilitates its insertion into the sleeve. For this purpose, the object can be tapered. In use it can be pushed as far into the sleeve as possible to form a seal. In this conical embodiment, the object does not have to be elastic, although it is of course preferably elastic. Elasticity may be provided by additional elastic material surrounding the object and in use contacting the inner surface of the sleeve.

In an alternative arrangement a lip may be formed on the object such that contact is additional or only between the outer surface of the sleeve and the object. With only unique contact between these two surfaces, the shape of the object is similar to container 90 of FIG. 6 .

At least a part of the upper surface of the object (the part where the wax tree 30 is attached) is water permeable. This allows the absorbent material to communicate with the slurry fluid. In one embodiment, a separate water permeable material (eg in layered form, which may also be water absorbent) may be formed or placed on top of the water absorbent material. Ideally, the object is easily penetrated by the slurry.

third embodiment

Fig. 4 shows a third embodiment. The third embodiment is the same as the second embodiment except as described below.

In the embodiment of FIG. 4 , the top outer surface of the absorbent object comprising absorbent material is shaped to fit within the sleeve 10 . That is, a step is formed in the object. The inner diameter of the sleeve is the smaller diameter and the outer diameter of the sleeve 10 is the larger diameter. The top portion may have the properties of the sealing member of the object of the second embodiment (eg elastic, tapered, etc.). A seal 330 may additionally be provided, for example in the form of an O-ring or a gasket or glue or wax. The seal 330 rests on the lip formed by the change between the smallest diameter and the largest diameter.

As noted above, Figure 4 shows an optional component band 210 (dashed line) that generates a radially inward force, for example as described in detail in the sixth embodiment. Said band 210 is part of the sealing member and contributes to a sufficiently tight seal between the sleeve 10 and the object to achieve the desired level of water tightness.

Further optional components are shown in Figure 4. The toothed portion 72 extends into the sleeve 10 further than the rest of the upper surface of the object. The toothed portion forms the base of the wax tree 30 (making the mold funnel-shaped). The remainder of the wax tree is attached to the top of the toothed portion 72 (which forms a truncated cone). The toothed portion 72 may have a hole on its upper surface to receive one end of the wax tree 30 . This avoids the need to use glue or other adhesives to attach the wax tree to the water permeable portion. The toothed portion can be integral, but is not required. Furthermore, it does not have to be water permeable or water absorbent.

The toothed portion may form part of any embodiment. For example it can be formed on the top 100 or on the water permeable material 20 .

Fourth Embodiment

Fig. 5 shows a fourth embodiment. The fourth embodiment is the same as the first embodiment except for the following.

In the embodiment of FIG. 5 , the object comprises a container 90 . The container 90 is composed of side walls 120 , a bottom 110 and a top 100 . The top and bottom can be in the form of plates, they can also have a different form, for example sheet form. At least a portion of the top 100 is formed as a water permeable portion. This is not equivalent to the permeable material 20 of FIGS. 1 and 2 . The bottom 110 may be impermeable or permeable. The top and bottom 100, 110 are preferably held by the side walls 120, but they can also be fixed in a different way, for example by glue.

Sidewall 120 is generally tubular in shape. It preferably has the same (external) section as the sleeve 10 . Sidewall 120 may also include a bottom lip 122 . Bottom lip 122 holds bottom plate 110 in place. Between the top and bottom 100 , 110 is a water absorbent material 70 . As with all other embodiments, the absorbent material 70 can be of any form. It may be in powder form, or it may be a solid object as in the second and third embodiments. In that case it is not necessary to have a separate top 100 as the top of the object has the necessary properties. The object does not have to be fixed to the container. The container can be reused for a new object comprising absorbent material, or the object itself can be reused. The reusable objects may be dried inside or outside the container 90 . Container 90 can be used for several objects. The top 100 can either be glued in place, or it can be placed, for example, in a recess in the inner surface of the side wall 120 . The above structure will be described and illustrated with respect to the fifth embodiment.

As seen, the sidewall 120 extends over the top 100 to form a sealing member 125, which may also be considered a stationary member. The sealing member 125 is dimensioned such that it contacts the outer surface of the bottom end of the sleeve 10 . Preferably, the material of the fixing part is elastic. This allows it to be arranged to generate a radial compressive force. This creates a good seal between the container and the sleeve 10 . The sealing member 125 thus protrudes from the top of the container 90 . The sealing member 125 protrudes from the edge of the container 90 beyond the top 100 of the container. The top 100 of the container is the water permeable part of the container. The internal cross-sectional shape of the sealing member 125 at rest is the same, preferably smaller than the external cross-sectional shape of the bottom of the sleeve 10 . The sealing member 125 is preferably elastic so as to deform radially outward. Preferably the sealing member is elastic. Preferably, the sealing member exerts a radial compressive force on the sleeve 10 when the container 90 is attached to the sleeve 10 .

The material of the sidewall 120 is preferably a polymer. Other materials may also be suitable. Metal side walls are also suitable; the container is then heated, for example during drying of the absorbent material. The side wall 120 may be, for example, an injection molded part. The compressive force exerted by the sealing member 125 on the sleeve 10 is preferably large enough to ensure that the container is attached to the sleeve 10 so that the hydrostatic pressure created by the water in the slurry 50 does not lift the sleeve 10 from the container. Preferably the seal produced by the sealing member has the properties described above. However, other components may be provided in order to increase the strength of the fastening and/or seal between the container and the sleeve 10 . For example an adhesive can be used. Alternatively or additionally, other clamping devices may be used. For example the clamping means may comprise an elastic band around the sealing member 125 to increase the compressive force on the sleeve 10 . Optionally, the clamping means may extend longitudinally around the sleeve 10 and container 90 to hold them together.

As shown, sealing member 125 has tapered edges. In this way, the inner diameter of the container gradually decreases as the distance from the edge increases towards the bottom plate 110 . This makes it easier to insert the sleeve 10 into the container.

The container of the second embodiment is relatively rigid. However the top and bottom 100, 110 may be flexible (eg made of sheet material). Optionally, they can be made thicker for ease of manufacture.

Fifth Embodiment

A fifth embodiment will now be described with reference to FIG. 6 . The fifth embodiment is the same as the fourth embodiment except as described below.

As in the case of the fourth embodiment, the fifth embodiment includes a container preferably composed of a material that renders the container rigid. In the fifth embodiment, the bottom 110 and the side wall 160 are integrally provided.

As shown in FIG. 6 , a dimple 167 (annular) is provided on the inner surface of the side wall 160 . The edge of the top 100 rests within the dimple 167 . If the side walls 160 are made of a resilient material such as plastic, the top (plate) 100 can be pushed into the container and snapped into the recess 167 after the absorbent material 70 is placed in the container. The details of the sealing member 165 of the embodiment of FIG. 6 are similar to those of the embodiment of FIG. 5 .

Sixth Embodiment

Fig. 7 shows a sixth embodiment. The sixth embodiment is the same as the third embodiment except as described below.

In the sixth embodiment, the sealing member 210 may be separated from the container 90 . The container 90 is formed in a similar manner to the sixth embodiment, except that the side walls 200 do not extend beyond the top 100 . It will be appreciated that the container may be otherwise shaped, as with the other embodiments, and may be constructed similarly to the container of the embodiment of FIG. 5, for example. That is, the bottom 110 may be configured not to be integrally formed with the side wall 200 .

In the embodiment of FIG. 7 , the top 100 is secured to the side walls 200 . Can be fixed by glue or other means. Alternatively or additionally, the entire container 90 is made of the same material.

The fixing part 210 is configured as an elastic sleeve. That is, the sealing member 210 is formed from a strip of elastic material and is in the shape of an annulus having an inner diameter which is smaller than the outer diameter of the container and sleeve 10 in the absence of any external force. The sealing member can be made of synthetic or natural rubber or any other elastic material.

Incidentally, the container 90 has substantially the same outer diameter as that of the sleeve 10 . Thus, when the sleeve 10 and the container are aligned, the sealing member 210 may be provided on the connection portion between the sleeve 10 and the container, thereby fixing the container to the sleeve.

The container of the embodiment of Figure 7 is provided with a sealing member which may be provided separately or already attached to the top of the container.

In a further modification, the sealing member 210 may be configured as an adhesive tape or the like. In that case the adhesive tape may not be in the form of an endless strip but in the form of a longitudinal strip long enough to surround the circumference of the sleeve 10 and the container 90 . Optionally, it is not necessary to provide tape around the entire perimeter, and sufficient force against hydrostatic pressure can be achieved simply by providing securing means 210 in the form of tape at appropriate locations around the perimeter of the sleeve 10 and container 90 . This is especially the case when the seal 330 is used as in the second and third embodiments, or when the sealing component comprises other components.

As described for the second embodiment, clamping members can optionally also be included, extending between the top of the longitudinal edge of the sleeve 10 and the bottom of the container 90 . Said clamps can be reused together with the sleeve 10 and the new container 90 during the preparation of the next mould.

Seventh Embodiment

Fig. 8 shows a seventh embodiment. The embodiment of FIG. 8 is the same as the fifth embodiment except as described below.

In a fifth embodiment, the sealing means include a mechanical interlock instead of using radial compressive forces to secure the container to the sleeve 10 . One way of doing this is through threads 310 on the container 90 which allow the container 90 to be screwed onto threads 320 formed on the bottom edge of the sleeve 10 . A gasket 330 or an O-ring may be provided between the top 100 and the end of the sleeve 10 . Gasket 330 is annular. Gasket 330 may ensure the watertight integrity of the connection between threads 310 , 320 .

An alternative to replacing the threads 310, 320 is a bayonet type fitting. At least one protrusion is provided on the outer surface of the sleeve 10 in a bayonet type fitting. Slots extending beyond the top plate 100 are provided in the side walls of the container. The protrusion slides into the slot when assembled. Relative rotation of the container 90 relative to the sleeve 10 thus effectively moves the protrusion into place in the slot such that the sleeve 10 does not substantially move away from the container 90 . One way of accomplishing this is to provide a slot with an L shape so that the protrusion travels from the top of the L to the base of the L and then along the base. One, two, or more protrusions and corresponding slots may be provided. It is advantageous to provide a biasing force in this embodiment. This biasing force acts to push the sleeve 10 away from the container 90 to hold it in place and prevent rotation. The biasing force may be provided by washer 330, for example. It is understood that components from one embodiment may be used in other embodiments.

Eighth embodiment

Fig. 9 shows an eighth embodiment. The eighth embodiment is the same as the third embodiment except as described below.

In the eighth embodiment, a container 90 (for example, the container of the fourth embodiment) is used. The protrusion from the bottom 110 forms the toothed portion 72 which is part of the container. A water absorbent material surrounds the base of the toothed portion 72 . That is, the water absorbent material 70 is in the shape of an endless belt so as to surround the toothed portion 72 . The toothed portion 72 extends from the bottom 110 of the container 90 through the absorbent material 70 to form the toothed portion 72 . The toothed portion 72 is separable from the remainder of the container 90 . It can, for example, be glued to the container. The toothed portion can be made of polymer. The top 100 (if provided) has a central through hole for the toothed portion to protrude through. Optionally, top 100 may be shaped (or formable). The absorbent material 70 can be recycled or discarded after one use.

In this embodiment the opening of the container is particularly wide, ie the inner diameter of the container is larger at the top than at the bottom. In fact the inner diameter of the top is greater than the outer diameter of the lower part. Edges curl outward for easier insertion. This feature can also be used in other embodiments. The side walls of the container widen slowly at the upper end to widen the opening of the container.

Ninth Embodiment

Fig. 10 shows a ninth embodiment. The ninth embodiment is the same as the eighth embodiment except as described below.

While it is clear from the above description that the toothed portion 72, the bottom 110, the sides 120 and the sealing member 125 may be made from a unitary piece, this is illustrated in Figure 10 for clarity. In Fig. 10, those parts are made from a single piece of material, for example from plastic material or rubber-like material or rubber. The components are similar to the embodiment of Fig. 6, especially for the sealing components and the side walls. The single piece of material is recyclable. The absorbent material 70 is a separate insert. It is annular. In other words it has a through hole. The through holes are frusto-conical. The water permeable top 100 may be fixed to the absorbent material 70, or may be freestanding. The top 100 could even be the same material as the absorbent material 70 . The absorbent material 70 may or may not be recyclable. The water-absorbent material 70 may be integral, for example made of wood or pulp.

A similar effect can be achieved by placing an insert such as that shown in Figure 4 into the container of any of Figures 5-8.

Preferably, the absorbent material 70 is fitted so that, in application, little, if any, water escapes between the toothed portion 72 and the inner surface of the absorbent material 70 . That is, a seal is created between the water absorbent material 70 and the notch portion 72 . Likewise, preferably no water leaks between the side wall 120 of the container and the water-absorbent material 70 .

One way to reduce the possibility of liquid leakage between the recessed portion 70 and the absorbent material is to ensure that the inner surface of the absorbent material is sloped less than the slope of the toothed portion 72 . This ensures that the water-absorbent material contacts the toothed portion 72 at the top of the water-absorbent material 70 rather than at the bottom near the bottom 110 of the container. Of course, the slope of the inner surface of the through-hole of the water-absorbent material 70 and the tooth-shaped portion 72 may be the same.

Tenth Embodiment

Fig. 11 shows a tenth embodiment. The tenth embodiment is the same as the ninth embodiment except as described below.

The tenth embodiment allows the water absorbent material to be used in powder form. This is done while avoiding the mess and health hazards associated with the use of powders. As seen from FIG. 11, an object comprising a water-absorbing material 70 is provided. The water-absorbing material 70 is accommodated in a tray 600 . The disc is round on request. The disc 600 defines a through hole for seating the toothed portion 72 . The surface of the disk 600 defining the through hole is sized and shaped in the same manner as the tenth embodiment. The material of the disc can be plastic or metal material. The top of the disc 600 is sealed with a top 100 made of a water permeable material. Inside the tray 600 is placed a water-absorbent material, preferably in powder form. One form of absorbent material is vermiculite. The top 100 of water permeable material may be glued or pressed into the tray 600 . The latter embodiment is easy to reuse, see below.

In a vertical section through the central axis of the disc 600 (as is the case in FIG. 11 ), the cross-section of the disc has two trapezoids. Of the two parallel lines of the trapezoid, the uppermost line is the longest. One of the two non-parallel lines of the trapezoid is substantially or approximately perpendicular to the two parallel lines. This geometry results in the formation of through-holes with a frusto-conical shape on the surface. It should be understood, however, that other shapes are also suitable. For example, the serrated portion 72 may be a pyramid shape or a hemispherical shape or a shape curved toward a wax tree progression. The sides of the toothed portion 72 form an arbitrary acute angle with the bottom 110 of the container. The base of the toothed portion 72 may have any shape in plan view including, but not limited to, triangular, square, circular, hexagonal, and the like. Asymmetrical shapes are also possible in plan and vertical section. Actually the shape of the notch portion 72 may not be regular in the vertical section. The base of the toothed portion 72 may be, for example, a conical hemisphere at the top.

In the embodiment of Fig. 11, the container 90 comprising the side walls, bottom and serrations can be reused multiple times. Each time the container is used, a new object comprising the disc 600, absorbent material 70 and top 100 is inserted into the container. The combination of pan 600, absorbent material 70 and top 100 can be discarded after use. Optionally, they can be dried and reused.

Eleventh Embodiment

Fig. 12 shows an eleventh embodiment. The eleventh embodiment is the same as the tenth embodiment except as described below.

In FIG. 12 the sleeve has been omitted, and only the object comprising the absorbent material 70 and the container 90 is shown.

The bottom 110 of the container 90 has at least one through hole 700 . For example, there may be four through holes 700 in the bottom 110 of the container 90 . The four through holes may be evenly distributed around the periphery of the container 90 . Vias 700 serve two purposes. The first purpose is to allow a tool or operator's fingers to press onto the disc 600 from below the container 90 through the through hole 700 , thereby facilitating removal of the disc 600 from the container 90 . A secondary purpose of the through holes 700 is to allow the extraction of gas from the object comprising the absorbent material 70 and the sleeve 10 . Gas is removed from the investment casting slurry by placing the entire assembly including sleeve 10 and container 90 in a vacuum chamber. By having through holes 700 in the bottom 110 of the container 90, gas and/or liquid can be drawn out of the assembly and gas in the container 90 can be prevented from being drawn through the slurry in the sleeve 10. The purpose of vacuuming is to remove gas from the slurry.

A plurality of other through holes 710 may be provided at the bottom of the disc 600 . The through hole 710 on the bottom of the tray 600 may be smaller than the through hole 700 on the bottom 110 of the container 90 . This is because they need not be sized to allow a tool or operator's fingers to pass through them; the through holes 710 at the bottom of the disc 600 merely ensure that the inside of the disc 600 is in fluid contact with the outside of the container 90 so that the vacuum can draw the gas And/or liquid is sucked out of the sleeve 10 and container 90 rather than through the slurry within the sleeve 10 .

To ensure that all through-holes 710 of the bottom of the disc 600 are in fluid contact with at least one through-hole 700 in the bottom 110 of the container 90 , grooves 720 may be provided on the inner surface of the bottom 110 of the container 90 . In this way, the disc 600 is supported by the bottom 110 of the container 90 , there is also fluid contact between the through holes 700 in the bottom 110 of the container 90 and the through holes 710 in the bottom of the disc 600 .

In order to ensure that the water-absorbent material 70 on the tray 600 does not fall through the through holes 710 , a porous partition 730 (eg, paper) may be placed at the bottom of the tray 600 . The partition 730 is also annular to match the contour of the bottom of the disc 600 .

In order to ensure that the sleeve 10 and the container 90 are easily placed in the vacuum chamber and that the interior of the sleeve 10 and the container 90 is connected to a vacuum, the bottom of the container 90 may be provided with a leg 740 . When the container 90 is located within the vacuum chamber, the container can stand upright on the feet 740 and this allows for a gap to exist between the bottom 110 of the container 90 and the surface on which the container 90 is placed. This allows gas and/or liquid to be sucked out through the through hole 700 in the bottom 110 of the container 90 .

If gases do not escape from the slurry through the absorbent material 70 when the assembly is placed in a vacuum, the through-holes and/or feet 740 and/or grooves 720 and/or porous barriers 730 may be provided in any other implementation as desired. way. In particular, the embodiments of Figures 2 and 5-11 all benefit from the components described above. Optionally, through-holes 700, 710 are provided in the side walls of container 90 and tray 600 so that feet 740 are not required.

Claims (49)

1. object that the model casting slurry that is used in the sleeve dewaters, at least a portion of the outer surface of wherein said object is permeable, thereby provide the fluid of the outside water-absorbing material with described object of described object to be communicated with, described object comprises and is used for described object is sealed to seal member on the end of sleeve.

2. object as claimed in claim 1, this object also comprises container, described container holds described water-absorbing material.

3. one kind is used for dewatering and holding the container of water-absorbing material from the fusible pattern slurry, described container comprise be used for removedly with described seal of vessel to the end of sleeve seal member and the parts of tooth that when described sleeve is sealed to described container, stretches into the bottom of described sleeve.

4. object as claimed in claim 2 or container as claimed in claim 3, wherein said seal member comprise from the outstanding part in the end of the sidewall of described container.

5. object as claimed in claim 2 or container as claimed in claim 3, wherein said seal member extends from the edge of described container.

6. as each described object in the claim 2,4 or 5 or as each described container among the claim 3-5, wherein said wall of a container portion is an one except described permeable part, preferably injection mo(u)lding.

7. as each described object in the claim 2,4,5 or 6 or as each described container among the claim 3-6, the sidewall of wherein said seal member and described container is an one.

8. as each described object in the claim 2,4,5,6 or 7 or as each described container among the claim 3-7, at least a portion of wherein said wall of a container forms described permeable part.

9. as each described container among the claim 3-8, wherein said water-absorbing material is ring-band shape and the base portion that centers on described parts of tooth.

As claim 1,2 and 4-8 in each described object, this object also comprises parts of tooth, this parts of tooth surpasses described permeable outer surface away from described water-absorbing material is outstanding.

11. object as claimed in claim 10, wherein said parts of tooth are the parts of described water-absorbing material.

12. as each described object among the claim 9-11 or as each described container among the claim 3-8, wherein said parts of tooth comprises the pit of the base portion that is used for inserting therein wax tree.

13. as each described object among claim 1 or the 10-12, the size and dimension of wherein said object is decided to be and can inserts under radial compression in the described sleeve, described seal member comprises the sidewall of described object.

14. as each described object among claim 1 or the 10-13, wherein said seal member is sealed to the madial wall of described sleeve by the biasing force by the resiliency compressible generation of described object.

15. as each described object or container among the claim 1-12, wherein said seal member utilizes radial compression force.

16. object as claimed in claim 17 or container, wherein said object have sidewall or described container has sidewall, described sidewall is enough firm to resist the compression of described seal member.

17. as each described object or container among the claim 1-12, wherein said seal member comprises that screw thread fixes.

18. according to each described object or container in the aforementioned claim, wherein said seal member is configured and is set under the hydrostatic pressure of at least 6 cm of water waterproof.

19. according to each described object or container in the aforementioned claim, wherein said seal member comprises elastomeric material.

20. according to each described object or container in the aforementioned claim, this object or container also comprise packing ring, described packing ring is used for contacting between described object and sleeve when described container is sealed to sleeve, thereby improves described sealing.

21. according to each described object or container in the aforementioned claim, wherein said water-absorbing material is made up of global facility.

22. according to each described object or container in the aforementioned claim, wherein said seal member extends around described permeable part.

23. according to each described object or container in the aforementioned claim, wherein said seal member is removable with respect to described object.

24. according to each described object or container in the aforementioned claim, wherein said seal member is configured and is arranged such that the inside of described water-absorbing material and described sleeve becomes the fluid connected state when the sealing parts are sealed to sleeve with described object.

25. object that the model casting slurry that is used in the sleeve dewaters, at least a portion of the outer surface of wherein said object is permeable, thereby provide the outside of described object to be communicated with the fluid of the water-absorbing material of described object, described object comprises through hole so that described object can be placed on the protuberance, thereby when described protuberance extended through described object, described water-absorbing material was around described protuberance.

26. object as claimed in claim 25, the described through hole of qualification of wherein said object the surface be frustum-like shape basically.

27. as claim 25 or 26 described objects, wherein said through hole is coaxial with the central axis of described object.

28. as each described object among the claim 25-27, it is circular that wherein said object is essentially in plane.

29. as each described object among the claim 25-28, wherein said water-absorbing material is accommodated in the dish, described dish limits described through hole.

30. object as claimed in claim 29, the opening of wherein said dish is by the permeable property material sealing that forms described permeable part.

31. as each described object among the claim 25-30, wherein said water-absorbing material is a powder.

32. according to each described object or container in the aforementioned claim, wherein said water-absorbing material be can be dry so that described object can re-use.

33. according to each described object or container in the aforementioned claim, wherein said water-absorbing material is at least one in gypsum, silica, wood pulp, paper pulp, the vermiculite.

34. according to each described object or container in the aforementioned claim, wherein said permeable part has at least 0.25 cubic centimetre/square centimeter/hour permeability under 0.5 centimetre head.

35. according to each described object or container in the aforementioned claim, but wherein said permeable part is made up of a kind of material that is selected from wood pulp, shaped cardboard, shaping vermiculite, porous plate, braided material, non-woven fabric founding water-absorbing material, plastics or the polymeric material.

36. as each described object among claim 1,10-12 or the 25-28, wherein said object is made up of global facility.

37. according to claim 3 or be subordinated to the described container of arbitrary claim of claim 3 and according to claim 25 or be subordinated to the combination of the described object of arbitrary claim of claim 25.

38. each described object or container or combination in the claim as described above, wherein said object also comprise removable or easily broken sealing, to seal the anti-sealing infiltration of described water-absorbing material, for example described object places fluid-tight packing.

A 39. model casting sleeve and according to each described object or container or combination in the aforementioned claim.

40. according to the described model casting sleeve of claim 39 and object or container or combination, wherein said sleeve has the parts that use by described seal member, described parts are used to utilize and mechanical interlocked described object are fixed to described sleeve.

41. a method for preparing investment casting mold, described method comprises:

One sleeve is provided;

By on the openend of described sleeve fixedly the seepage of water material block described openend; And

On a side opposite of described seepage of water material, provide water-absorbing material with described sleeve,

Wherein said water-absorbing material is held togather, and is constructed and arranged to guarantee that the fluid between described water-absorbing material and described sleeve inner is communicated with.

42. method as claimed in claim 41, wherein said seepage of water material are the surfaces of described water-absorbing material.

43. as claim 41 or 42 described methods, wherein said water-absorbing material is made up of global facility.

44. as claim 41 or 42 described methods, wherein said water-absorbing material keeps together by container, at least a portion of this wall of a container is permeable.

45. method as claimed in claim 44, the described permeable part of wherein said container are the described seepage of water materials that is fixed on the openend of described sleeve.

46. method as claimed in claim 41, this method also comprises: will put into the described container of arbitrary claim as claimed in claim 3 or any claim appended thereto as claim 25 or the described object of arbitrary claim that is subordinated to claim 25, and use described seal member with described seal of vessel to described sleeve.

47. method as claimed in claim 41, wherein said water-absorbing material is as the described object of arbitrary claim of claim 1 to 38 or the water-absorbing material of container or combination, and perhaps described object or container or combination and sleeve are according to claim 39 or 40 described objects or container or combination and sleeve.

48. one kind basically with reference to above description and illustrated in the accompanying drawings container.

49. one kind basically with reference to above description and illustrated in the accompanying drawings method.

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