WO2007132198A1

WO2007132198A1 - Pressure casting apparatus, system and methods

Info

Publication number: WO2007132198A1
Application number: PCT/GB2007/001731
Authority: WO
Inventors: Christopher Moore; Nicholas Riddington
Original assignee: Pcl Ceramics Ltd
Priority date: 2006-05-11
Filing date: 2007-05-11
Publication date: 2007-11-22
Also published as: EP2089198A1; GB0609297D0

Abstract

A mould press apparatus adapted for pressurised slip casting of a ceramic article, the apparatus comprising a supporting framework module within which a mould housing (5) comprising at least one mould member is located, said member (s) formed to be capable of pressurised moulding of said ceramic article within said housing, clamping means (8) adapted to at least partially clamp the mould member (s) to form said housing, ceramic slip introducing means adapted to introduce said slip into the mould housing, pressurising means adapted to apply pressure to the slip within said mould housing, wherein said framework module is configured to restrict movement therein of the mould housing in a generally vertical direction to prevent generally vertical demoulding of the moulded article whilst within said framework module but arranged to permit withdrawal of the at least partially clamped mould housing in a generally horizontal direction away from said framework so as to permit generally vertical demoulding of the moulded article in a location spaced away from the said framework module.

Description

PRESSURE CASTING APPARATUS, SYSTEM AND METHODS

This invention is concerned with pressure casting apparatus, systems and methods principally for the production of ceramic products by pressurised slip casting. In particular the invention is concerned with apparatus constructed for the production of ceramic products such as ceramic sanitaryware, such as ceramic houseware for example sinks, basins, pedestals, vanity units and/or toilet bowls. Preferred embodiments of the invention are directed to the production of ceramic toilet bowls wherein a plurality, such as two, three or possibly four individual ceramic articles are constructed by pressurised slip casting and then assembled into the final product.

The pressure casting of ceramic toilet bowls in particular is a complex multi-stage process including simultaneous or sequential casting of component articles and subsequent assembly operations. Specially fabricated casting machines have been used for these purposes, but there are a number of drawbacks associated with their construction and use. For instance, the known such casting machines have of necessity been large framework installations of considerable complexity arising from the need to manipulate and move the mould parts within the confines of such machines in multiple complex sequences.

We have now found that the size and complexity of such casting machines can advantageously be reduced and hence we propose an alternative structure for such casting machines, which is less bulky and more economical to produce and use. We have also found that manipulation of mould housings associated with such casting machines can be improved by restricting or minimising the use of manual labour and/or fork lift trucks which hitherto have been necessary or desirable in handling the moulds and the moulded articles. In particular we have now developed pressure casting apparatus, systems and methods wherein movement of the mould housings including demoulding of the ceramic articles can be performed by means of a multiple axis manipulator, such as a robotically controlled arm, or by apparatus which comprises a robotically operated arm. For brevity such items will be referred to herein as a 'robot arm'.

Robot arms in themselves are known items of industrial hardware, and many are used in industrial assembly operations such as in the automated or semi-automated production of motor vehicles. They are known and used as labour saving, and hence cost saving, devices to perform manipulations of components in multiple axes. However the application of robot arms to the manipulation of multiple mould parts is apparently novel

Accordingly the present invention is directed to, in at least one aspect, the use of at least one multiple axis manipulator such as the aforementioned robot arm to manipulate, i.e. to move by displacement and/or orientation, the ceramic mould parts but especially ceramic sanitaryware mould parts, moulded articles and finished moulded product. Hence we have now surprisingly found application of such manipulators for the purpose of reducing the size and complexity of the casting machines, and to facilitate not only the required movements of e.g. the ceramic mould housings and the demoulding of ceramic articles therefrom but also in the assembly operations for producing the intended finished ceramic product by assembling together in appropriate steps and movements, the demoulded individual ceramic articles which make up the intended final product.

Additionally, we have found that the gripper component of the manipulator can be modified to include moving parts such as moving locators which can assist in the removal of mould parts such as mould covers from the mould housing. Accordingly the invention provides a multi-axis manipulator as a component of the present pressure casting apparatus and systems, wherein the end gripper component has the capacity itself to move apart the mould pieces so as to remove the cast article and/or to perform subsequent operations upon it. The present pressure casting methods therefore also embody the use of such a gripper arrangement.

According to one aspect of this invention, there is provided a mould press apparatus adapted for pressurised slip casting of a ceramic article, the apparatus comprising a supporting framework module within which a mould housing comprising at least one mould member is located, said member(s) formed to be capable of pressurised moulding of said ceramic article within said housing, clamping means adapted to at least partially clamp the mould member(s) to form said housing, ceramic slip introducing means adapted to introduce said slip into the mould housing, pressurising means adapted to apply pressure to the slip within said mould housing, wherein said framework module is configured to restrict movement therein of the mould housing in a generally vertical direction to prevent generally vertical demoulding of the moulded article whilst within said framework module but arranged to permit withdrawal of the at least partially clamped mould housing in a generally horizontal direction away from said framework so as to permit generally vertical demoulding of the moulded article in a location spaced away from the said framework module.

According to a second aspect of this invention, there is provided a method of demoulding a ceramic article from a pressurised slip casting module, in which an at least partially clamped mould assembly initially located within said module is charged with ceramic slip, sealed and pressurised, the mould assembly whilst still at least partially clamped being withdrawn generally horizontally from said module by means of a multi axis manipulator, said manipulator subsequently inverting said mould housing, the moulded ceramic article being demoulded spaced away from said module, said manipulator subsequently re- inverting the at least partially clamped mould housing and returning it to its original location within said module.

Preferred features of the invention, including preferred features of a system of mould apparatus are to be found amongst the sub Claims herewith.

Principal advantages attributable to the present invention include improved economics in the construction and use of casting machines, i.e. casting framework modules as referred to above. The flexibility of the apparatus, system and methods is similarly improved. Additionally, product changeover, i.e. ceramic article displacement, manipulation and assembly can be accelerated in the production of multi-component, i.e. multiple ceramic article finished products. This advantage is of particular benefit in the construction of ceramic sanitaryware and especially so in the production of ceramic toilet bowls by pressurised slip casting. These advantages may also apply in the construction and assembly of other articles.

By incorporating a multiple axis manipulator, the required manipulations and movements of the mould parts and moulded articles can all be undertaken by that manipulator, e.g. by the robot arm. This significantly reduces the complexity and hence cost of the casting machines (framework modules) required in the manufacture of the end product. Instead of multiple motion systems associated with and built into each casting module, the modified casting modules have become simplified, smaller, less bulky, less expensive and have only 'short stroke' clamping requirements for holding the mould parts against the applied pressure from the pressurised slip.

In essence, all the larger scale mould housing and ceramic article movements can then be performed by a single general purpose mechanism, i.e. the multiple axis manipulator such as a robot arm. Furthermore, additional benefits stem from automation of mould changing which hitherto had required manual operations.

In order that the invention in all its aspects and the preferred or optional features thereof may be illustrated, more readily appreciated and carried into effect by those skilled in the art, reference will now be made to the accompanying drawings which are illustrative of the invention by way of non-limiting example only, and wherein:

Figure 1 is an informal photograph depicting one suitable form of modified framework casting module associated with a robot arm, together forming a pressurised slip casting system;

Figure 2 is a schematic illustration from above, of a multi-component pressurised slip casting system including two separate spaced ceramic article casting framework modules, a support for an optional tertiary ceramic article, and a robot arm all for constructing a ceramic toilet bowl; and

Figure 3 is an informal photograph of a modified robot arm, with an alternative gripper means at the rotatable head able to move apart and close component parts of the mould assembly to assist demoulding away from the module. Referring to the drawings and initially to Figure 1 thereof, one suitable form of modified pressurised slip casting framework module (1) is shown. This is a simplified framework, less bulky and more economical than the conventional frameworks within which it is possible to demould ceramic articles in a generally vertical direction. In this framework there is a limited upward (generally vertical) movement of the mould housing (5) whereby a stroke of some 20 to 150, preferably 30 to 100, more preferably 40 to 8 mm of movement is permitted hence in this module it is not possible to demould the formed ceramic article (not shown) from the mould housing within the confines of the framework module in a generally vertical direction.

The illustrated frame assembly (1) is comprised of four similar upright supporting posts (2) spaced apart around a base (3) and terminating at an upper section (4) to define the boundary of the framework. Between the base (3) and a short stroke clamping press (8) a mould housing (5) is located, and which can be inserted into and removed from the framework (1) in a generally horizontal direction through an opening (6) between a pair of the spaced upright supporting posts (2). The mould housing (5) can be a multi, i.e. 2 or more part sub assembly if desired. Suitable clamping arrangements will be needed (not shown) for vertically split such mould components The mould housing is adapted to be supplied with pressurised ceramic slip by slip introducing means. The short stroke clamping press (8) is adapted to cover the top of the mould housing and be pressed against it to form a corresponding seal during introduction of the slip. The mould is dewatered at this point if required and the clamping press (8) released, sufficient to make a short stroke clearance between itself and the top of the mould housing.

The system of apparatus shown in Figure 1 further includes a remote robot arm (10) securely affixed to the ground by means of floor mounting (11) and having the multiple axis manipulator arm (12) and rotatable end piece (13). Various accessory parts can be fitted to that end piece (13) as described hereinafter. The robot arm is spaced apart from the modified mould casting framework module (1) and operated by conventional means which need not be described here in further detail. The robot arm can be programmed to make the necessary manipulations and other movements.

Also spaced from the module (1) and robot arm assembly (10) is a remote support (7) optionally carrying a preformed ceramic article, such as a preformed tertiary ceramic article as needed for the end product such as the preferred item of ceramic sanitaryware such as the multi component toilet bowl. Whilst the support (7) and article (9) are optional, Figure 1 depicts in its simplest form a system of apparatus for producing ceramic articles with one framework casting module and one multiple axis manipulator.

Figure 2 herewith is illustrative of the necessary components according to the invention for producing a tri-component ceramic product, namely a finished three part ceramic toilet bowl. Here there is shown a pair of separate and slightly different framework casting modules 1A and 1B. Each will correspond generally with the type of framework depicted in Figure 1 , although there are additional clamping means for securely holding the mould housings to receive the ceramic slip under pressure.

The robotic arm (10) corresponds generally to that depicted in Figure 1, save that its rotatable end (13) is fitted with an adaptor (14) from which prongs (25) and grippers (26) extend in a generally horizontal plane relative to that adaptor in its rest position. The robot arm has a circular sweep depicted generally by the circular path (29) and a displacement distance at least that represented by the length of the sector (30). Mould casting module (1A) is constructed to make the ceramic bowl component (15) as a primary ceramic article in a multi part ceramic sanitaryware product. The mould housing has sides or side plates (20,21) clamping rams (18,23) a removeable upper plate (22) with vertically disposed rams (23) which can be held by stand 17 to remove that upper plate after removal of the mould housing generally horizontally from the module (1A). The robot arm adapter (14) can similarly replace that uppermost plate (22) and return the mould housing to the module (1A) after demoulding the formed ceramic toilet bowl (not shown).

The secondary module (1 B) is structurally similar to the module (1A) but is adapted to produce a different ceramic article, namely a rim (16) for the bowl. Like reference numerals have been used therein to depict the same or closely similar features.

It will be appreciated that module (1A) is separate and spaced from module (B), and both can be operated independently in appropriate sequence in the manufacture of an assembled toilet bowl. This system of apparatus for producing ceramic articles also has a separate, spaced support member (17) in the nature of a parking station. This support member (17) can be used for the temporary storage of mould parts while manipulation operations are being performed. It is supplied with an already formed tertiary ceramic article (17) or mould therefor, such as a rim mould and/or ceramic articles

In operation, the robot arm undertakes required manipulations and other movements of the mould casings and of the demoulded articles and the assembly of the articles into the finished product. Thus in further detail referring still to Figure 2, the robot arm removes the mould from the body casting module (1A), and leaves the rim mould (15) on the parking station at (17). The robot moves the mould for application of paste (not shown) and for cutting as required (not shown). The ceramic rim framework casting module (1B) opens, the top mould is moved out generally horizontally and inverted by the robot arm. The toilet bowl body is then brought into alignment with the rim and clamped. The rim section is demoulded and the robot arm brings the bowl to the demoulding station. The bowl is then inverted and positioned on the setter.

The mould sides are opened and the robot arm raises leaving the bowl on the setter in the inverted position.

Referring lastly to Figure 3, the robot arm is depicted with an alternative adaptor (14) at the rotatable end piece (13), in which projecting arms (27) are capable of lateral displacement with respect to the adaptor (14) by means of suitable mechanism (28). This system shows a gripper on the robot arm for removing the assembled moulds from the clamping unit(s). The gripper can move the mould pieces apart to remove, i.e. demould the cast article, and to perform further work on it.

Claims

1. A mould press apparatus adapted for pressurised slip casting of a ceramic article, the apparatus comprising a supporting framework module within which a mould housing comprising at least one mould member is located, said member(s) formed to be capable of pressurised moulding of said ceramic article within said housing, clamping means adapted to at least partially clamp the mould member(s) to form said housing, ceramic slip introducing means adapted to introduce said slip into the mould housing, pressurising means adapted to apply pressure to the slip within said mould housing, wherein said framework module is configured to restrict movement therein of the mould housing in a generally vertical direction to prevent generally vertical demoulding of the moulded article whilst within said framework module but arranged to permit withdrawal of the at least partially clamped mould housing in a generally horizontal direction away from said framework so as to permit generally vertical demoulding of the moulded article in a location spaced away from the said framework module.

2. A mould apparatus system comprising a plurality of mould press apparatus as claimed in Claim 1 , in which separate such apparatus within the plurality is adapted and configured to produce ceramic articles of different shape and/or size by pressurised slip casting.

3. A mould apparatus system as claimed in Claim 2, in combination with support means upon which the ceramic article to be formed or upon which another ceramic article already formed can be located.

4. A mould apparatus system as claimed in Claim 2 or 3, in combination with a multiple axis manipulator adapted to withdraw a mould housing away from its supporting framework module to permit or facilitate demoulding of the moulded ceramic article therefrom.

5. A system as claimed in Claim 4, in which the manipulator is capable of engaging said mould housing, withdrawing said housing away from its associated framework module in a generally horizontal direction, inverting if required said housing, and replacing said housing into said framework module after demoulding the ceramic article therefrom onto a preferably stationary support.

6. A system as claimed in Claim 4 or 5, in which the manipulator is constructed to be capable of removing, when present, an uppermost mould member from the mould housing.

7. A system as claimed in any one of Claims 4 to 6, in which the manipulator is or comprises a robotically controlled arm.

8. A system as claimed in any one of Claims 4 to 7, comprising a primary ceramic article casting module as defined in Claim 1 , and adapted to produce a primary ceramic moulded article, a secondary ceramic article casting module as defined in Claim 1 and adapted to produce a secondary ceramic article, both modules comprising a static framework assembly provided with moving parts for introducing ceramic slip, for securing mould members together which define the mould housing and for applying pressure to the slip within the mould housing, the system further including support means optionally provided with a tertiary ceramic moulded article, said manipulator constructed and arranged to remove from their associated module and demould said primary and secondary moulded articles, to assemble the required final ceramic product from said primary, secondary and if present, tertiary ceramic articles, and to return the mould housings to their original positions within the primary and secondary casting modules.

9. A method of demoulding a ceramic article from a pressurised slip casting module, in which an at least partially clamped mould assembly initially located within said module is charged with ceramic slip, sealed and pressurised, the mould assembly whilst still at least partially clamped being withdrawn generally horizontally from said module by means of a multi axis manipulator, said manipulator subsequently inverting said mould housing, the moulded ceramic article being demoulded spaced away from said module, said manipulator subsequently re-inverting the at least partially clamped mould housing and returning it to its original location within said module.

10. A method of making a ceramic product which involves producing a primary ceramic article by pressurised slip casting within a primary casting module as defined in Claim 9, demoulding that primary article according to a method as claimed in Claim 9, producing a secondary ceramic article by pressurised ceramic slip casting within a secondary casting module spaced from the primary such casting module, bringing the primary demoulded ceramic article into contact with said secondary ceramic article and causing them to be joined or sealed together, and optionally coupling the primary or secondary ceramic article with a tertiary and/or further ceramic article and if used causing that or those further articles to be joined or coupled thereto so as to form a completed ceramic product from said demoulded primary and secondary articles and if present said tertiary and/or further ceramic articles.

11. A method of demoulding a ceramic article as claimed in Claim 9, or a method of making a ceramic product as claimed in Claim 10, wherein said multi-axis manipulator is or comprises a robotically controlled arm.

12. A method as claimed in any one of Claims 9 to 11 , wherein the ceramic article or product is an item of sanitaryware, such as sanitary houseware.

13. A method as claimed in Claim 12, in which the product is a 2- or 3- part toilet bowl.

14. A mould press apparatus as claimed in Claim 1 or 2, or a mould apparatus system as claimed in any one of Claims 3 to 8 substantially as herein described.

15 A mould press apparatus as claimed in Claim 1 or 2, or a mould apparatus system as claimed in any one of Claims 3 to 8 substantially as herein illustrated.

16. A mould press apparatus as claimed in Claim 1 or 2, or a mould apparatus system as claimed in any one of Claims 3 to 8 substantially as herein exemplified.

17. A method of demoulding a ceramic article as claimed in Claim 9 or 11 , or a method of making a ceramic product as claimed in any one of Claims 10 to 13 substantially as herein described.

18. A method of demoulding a ceramic article as claimed in Claim 9 or 11 , or a method of making a ceramic product as claimed in any one of Claims 10 to 13 substantially as herein illustrated.

19. A method of demoulding a ceramic article as claimed in Claim 9 or 11 , or a method of making a ceramic product as claimed in any one of Claims 10 to 13 substantially as herein exemplified.