EP3122525A1

EP3122525A1 - Pressure casting apparatus and method

Info

Publication number: EP3122525A1
Application number: EP14772217.7A
Authority: EP
Inventors: Christopher Bernard Moore
Original assignee: Pcl Ceramics Ltd
Current assignee: Pcl Ceramics Ltd
Priority date: 2013-10-02
Filing date: 2014-09-22
Publication date: 2017-02-01
Also published as: GB2518856B; GB2518856A; GB201317449D0; WO2015049486A1

Abstract

The invention comprises a ceramic pressure casting machine, said machine comprising an elongate support (4), a mould (8), an attachment (6), and a mould transport (10), wherein the mould (8) comprises at least two portions (12,14) and wherein in use, slip is introduced to the mould (8) in a first, casting position, in which position the attachment (6) overlies the mould (8) and wherein the mould (8) is compressed by the pressing of the attachment (6) onto the mould (8) for a given casting period and wherein, subsequent to the casting period, the mould (8) is moved along the support (4) by the mould transport (10), such that the attachment (6) no longer overlies the mould (8), to a second, position, wherein the mould (8) may be opened whereby demoulding may be undertaken and wherein the mould (8) may subsequently be moved back along the support (4) by the mould transport (10) to the first position. The invention also comprises a method of pressure casting using a mould (8) comprising at least two portions (12,14) and an elongate support (4) comprising the steps, in this order, of casting in a first position, moving the mould (8) along a linear path along the elongate support (4) to a second position, in use, above the first position, opening the mould (8) in the second position; and demolding in the second position, using a portion of the mould (8) as a demoulder head.

Description

and method

Ba .Qi.thjLinvention

The invention relates to an apparatus and a method for pressure casting articles such as sanitary ware - including toilet bowls - in ceramic materials.

Pressure casting of ceramics is a well established method of the production of tableware, sanitary ware and technical ceramics, offering an effective way of turning liquid slip into an acceptably firm, moulded body, far more quickly than is possible using traditional casting methods.

This process operates thus: a preformed, microporous mould Is closed using mechanical means and filled with slip or slurry. The slip/ slurry is then subjected to pressure, which serves to push the water out of the slip/ slurry and through the pores of the mould, leaving cast pieces of sufficient strength to support their own weight. These cast pieces are then removed from the mould, with the assistance of compressed air blown through the pores of the mould., then subsequently assembled and finished.

Typical pressure casting machines require sufficient opening distance between the two mould halves to allow removal of the cast object from the mould. The consequence of this is that the dosing and clamping mechanisms tend to be heavy and/or complex and costly, they take up a large amount of room and are wasteful

There is therefore a real need for a smaller, simpler and more energy efficient casting machine. it is these problems, amongst others, to which the invention attempts to provide one or more solutions. Summary, of thejnventlon

The invention has particular and immediate application to the production of toilet howls, sinks and similarly large, multi-part pieces of ceramic sanitary ware and as such will be discussed at length in relation to them, but has general application to all spheres in which pressure casting is utilised. in a first, broad, independent aspect, the invention comprises a ceramic pressure casting machine, said machine comprising an elongate support, a mould, an attachment, and a mould transport, wherein the mould comprises at least two portions, and wherein in use, slip is introduced to the mould in a first, casting position, in which position the attachment overlies the mould and wherein the mould is compressed by the pressing of the attachment onto the mould for a given casting period and wherein, subsequent to the casting period, the mould is moved along the support by the mould transport, such that the attachment no longer overlies the mould, to a second, position, wherein the mould may be opened whereby demoulding may be undertaken and wherein the mould may subsequently be moved back along the support by the mould transport to the first position.

The newly devised ceramic pressure casting machsne advantageously allows for a machine with a small clamping mechanism - typical pressure casting machines require sufficient opening distance between the two mould halves to allow removal of the cast object from the mould. The consequence of this is that the closing and lamping mechanisms can become heavy and/or complex and costly; here, because the mould is transportable into and out of the clamping mechanism, there is no need for this large space. The mould can be removed from the area of the attachment and as such the mould damping mechanism comprised by the attachment needs very little travel - in some instances as little as 5 mm. As such, a much smaller machine can be made and smaller size saves on space, but also on resources used to make the machine and energy used to power it; as such, the

environmental impact of the making and operation of the machine is lessened.

Preferably, during movement from the first position to the second position,, the mould is slid along the support, The sliding movement ensures continuous contact between mould and attachment which in turn leads to the saving of space and wear on the components of the pressure casting machine.

Preferably, the support is arranged, in use, such that it is vertical or offset from the vertical by an amount in the order of 20 degrees and in use, the second position is above the first position.

The vertical disposition of the new machine ensures that it has a smaller footprint - such a small footprint allows for example for multiple pressure casting machines to be grouped around a single robot, thereby allowing for the creation of an efficient multiple casting system.

Preferably, the movement of the mould from the casting position is along a board, said board comprising at least a mould contacting layer of low friction material

Preferably, the path of the mould from the first position to the second position and vice versa is a substantially straigh linear path.

The implementation of the straight linear path saves space and energy due to economy of movement.

Preferably, the mould comprises a conduit for the introduction of services to the interior of the mould and the machine further comprises a coupling, said coupling comprising an aperture in the surface of the board and a flange, the said components being so arranged that when the mould is in the first position, the conduit of the mould and the flange and aperture of the machine form a fluid connection.

The conduit and aperture/flange combination dispenses with the need for a slip hose, The slip hose has been used in ail previous pressure casting machines. Using a slip hose requires the manual hooking and unhooking of the hose to the mould. Not only is the hose perishable and unwieldy with a tendency to break, injure the user and generally to leak and make a mess around the work area, but the very fact that it requires manual intervention means that the slip hose is costly terms of time and in that it requires human intervention to utilise,

Preferably, the attachment comprises at least a layer of lay fiat tubing and wherein, in use the said layer is attached to a fluid source and wherein, in use, the lay flat tubing is expanded by the introduction of fluid into it, such that the attachment expands and in so doing compresses the mould.

Lay flat tubing is particularly useful in the context of the expanding/compressing layer because It can compress down virtually flat and takes up very little space in its compressed phase. Second, such tubing is cheap and easy to repair and replace.

Preferably, the attachment is attached to the machine by way of a series of height adjustable attachments.

More preferably, the height adjustable attachments comprise a plurality of threaded tie- bars.

Adjustable height attachments allow for quick changes to be made in order to

accommodate different moulds within the pressure casting machine; this suits the machine to experimental moulding particularly well,

Preferably, the mould comprises at least an attached half and a removable half and wherein the removable half is so sized and shaped as to be suitable for use as a demoukJer bead during demoulding. This configuration saves space, the number of items required in an end-to-end casting process as such also saves energy and speeds up the process.

The invention also comprises a pressure casting machine substantially as described herein, with reference to and as illustrated by any appropriate combination of the text and/or drawings.

In a second broad, independent aspect the invention comprises a method of pressure casting using a mould comprising at least two portions and an elongate support comprising the steps, in this order, of casting in a first position, moving the mould along a linear path along the elongate support to a second position, in use, above the first position, opening the mould in the second position; and demou!ding in the second position, using a portion of the mould as a demoulder head, This method confers the advantages of ciaimsl and 10 and generally saves time, space and resources.

Preferably, the opening of the mould and the demoulding are accomplished by a single robot arm,

Again, the utilisation of a single robot, arm saves space, energy and resources.

The invention also comprises a method of pressure casting substantially as described herein, with reference to and as illustrated by any appropriate combination of the text and/or drawings.

Bne Description of the Prj¾gjngs

The invention will be described in relation to the drawings, of which:

Figure 1 is a diagrammatic side eievational view of a pressure casting machine in a first casting position, Figure 2 is a diagrammatic side elevations! view of a pressure casting machine n a second, open position,

Figure 3 is a diagrammatic side elevational view of a pressure casting machine in a third, demoulding position, accompanied by an appropriate robot, and

Figure 4 is a diagrammatic front elevational transparent view of a pressure casting machine.

At Figure 1 there is a ceramic pressure casting machine indicated generally at 2. The machine 2 comprises in its essential elements an elongate support 4, an attachment 6, a mould 8 and a mould transport 10, In use, the operation of the machine 2 is thus: the mould 8 is filled with clay slip and is then compressed by attachment 6. The attachment 6 continues to compress the mould 8 until the casting process is finished, after which the attachment 8 releases the mould 8 such that transport 10 moves the mould vertically up the support 4 into the opening position, as illustrated in Figure 2. This process may be manual or fully or partially automated.

Figure 3 shows the mould 8, which in this embodiment is a two-part mould comprising an attached half 12 and a flying half 14 which can be split apart such that the flying half 14 is removed - here by a robot 16 - from the attached half 12, In this instance, where automated demoulding is employed, an additional advantage is that the robot 16 can use the flying half 4 as a demoulder head, avoiding the need for a custom designed demoulder head.

Returning to Figure 1, the support 4 comprises a ground engaging base 18 which in preferred embodiments will be firmly fixed to the ground with bolts or the like. The base 18 has a pedestal 20 projecting from it in an upwards direction, The pedestal 20 has a vertical back edge 22 and an angled front edge 24 such that In cross-section the pedestal 20 can be seen to be of a frusto-conical shape. The pedestal 20 may be a single, solid object or may consist of a plurality of plates and bars. The angled front edge 24 may be vertical it is likely to be offset from the vertical by an amount of the order of 20°, allowing the rest of the machine to be orientated similarly offset or obliquely to the vertical The pedestal 20 also comprises a conduit 26 through which services including clay slip can be fed into the mould. The conduit 26 runs through the pedestal 20 and further through fascia board 28, terminating in coupling 30. Coupling 30 serves to couple with aperture 32 of attached half 12; it is through this aperture 32 that clay slip is introduced into the mould 8, The coupling 30 comprises a resilient sealing arrangement 34 at its exit face, essentially comprising a rubber sealing element 36 and a fiat flange 38, These serve to co- align the conduit 26 with the aperture 32 in the attached half 12 of the mould 8, allowing the introduction of slip, in use. The support 4 comprises a central plate 40 onto which fascia board 28 is mounted. The central plate 40 is of a metal or alloy construction. Fascia board 28, which runs essentially along three quarters of the length of the machine 2 is made of a water repelling substance such as a slippery plastic it is on the central plate 40 that attachment 6 is mounted, via tie bars 42. The tie bars 42 comprise threaded bolts such that the attachment 6 may be mounted on said bars 42, nearer or further away from the fascia board 28, such that machine 2 can accommodate moulds 3 of different sixes. Attached to the back of the central plate 40 are lamps 44 which grip upright tube 46. Upright tube 46 projects upwards and upon upright tube 46 is mounted rod less cylinder 48, which is mounted to the upright tube 46 via cylinder mounts SO at either end, To rodless cylinder 48 there is attached a service pipe/energy chain 52, which in turn Is attached to blade 54; rodless cylinder 48, service pipe 52 and blade 54 comprise the transport 10, and serve to provide the means of moving mould 8 from the casting position wherein mould 8 is disposed towards the bottom end 56 of the machine 2, to an open position wherein the mould 8 is disposed towards the top end 58 of the machine. Blade 60 moves up and down rodless cylinder 48, thereby transporting mould 8.

The attachment 6 comprises an outer layer 62, which is preferably steel, and an inner layer 64, which in this embodiment is of aluminium, The outer layer 82 and the inner layer 64 surround expanding / compressing layer 56. In preferred embodiments this expanding / compressing layer 66 which comprises the clamping means is flattened flexible tubing also known as lay-flat tubing, although compression during the casting process can be achieved by hydraulic, pneumatic or mechanical means - in the latter case by means such as one or more screw threads. During clamping, fluids are pumped into the lay flat tubing, thus expanding it The fluids are then drained out in order to return it to its original state, The lay fiat tubing expanding/compressing layer 86 is made of high pressure polyester textile piping reinforced with a co-extruded polyurethane sheath. Other materials may be appropriate. Other damping means can be used, for example one or more short travel hydraulic cylinders.

Although the example here shows a pneumatic rod less cylinder 48, hydraulic, electrical and mechanical means - in the latter case such as a screw arrangement - may be used to propel the mould 8 up and down the support 4, The service pipe 52 may carry switches, sensors, water, electricity or slip singularly and/or in combination as appropriate.

At Figure 3, a robot 16 is shown demoulding the mould 8 by removing the flying half 14 of the mould from the attached half 12 of the mould S, The robot 16 may be substituted by manual means but an advantage of using the system of the machine 2 is that there is an improvement in precision in positioning the demoulded product, which has benefits if the demoulded product is to be joined with other cast items. A single robot 18 may be used to open and demould the moulds 8 of a number of machines 2 placed around the robot In a different system, additional equipment could be used to remove the flying half 14 of the mould 8 whilst the robot 18 operates directly on the demoulded work piece (not shown) itself.

Demoulding may be done manually, automatically or via a combination of manual and automatic aspects. An automated demoulding system may be used with one or more of the machines 2 to create a larger, automatic casting system,

Claims

1. A ceramic pressure casting machine, said machine comprising an elongate support, a mould, an attachment, and a mould transport, wherein the mould comprises at least two portions, and wherein in use, slip is introduced to the mould in a first, casting position, in which position the attachment overlies the mould and wherein the mould is compressed by the pressing of the attachment onto the mould for a given casting period, and wherein, subsequent to the casting period, the mould is moved along the support by the mould transport, such that the attachment no longer overlies the mould, to a second, position, wherein the mould may be opened whereby demoulding may be undertaken and wherein the mould may subsequently be moved back along the support by the mould transport to the first position.

2. A machine according to claim 1, wherein, during movement from the first position to the second position, the mould is slid along the support,

3. A machine according to either claim 1 or claim 2, wherein the support is arranged, in use such that it is vertical or offset from the vertical by an amount in the order of 20 degrees and in use, the second position is above the first position,

4 A machine according to any of the preceding claims, wherein the movement of the mould from the casting position is along a board, said board comprising at least a mould contacting layer of low friction material

5. A machine according to any of the preceding claims, wherein the path of the mould from the first position to the second position and vice versa is a substantially straight, linear path.

6. A machine according to any of the preceding claims, wherein the mould comprises a conduit for the introduction of services to the interior of the mould and the machine further comprises a coupling, said coupling comprising an aperture in the surface of the board and a flange, the said components being so arranged that when the mould is in the. first position, the conduit of the mould and the flange and aperture of the machine form a fluid connection.

7. A machine according to any of the preceding claims, wherein the attachment comprises at least a layer of lay flat tubing and wherein, in use the said layer is attached to a fluid source and wherein, in use, the lay flat tubing is expanded by the introduction of fluid into it, such that the attachment expands and in so doing compresses the mould.

8. A machine according to any of the preceding claims, wherein the attachment is attached to the machine by way of a series of height adjustable attachments.

9. A machine according to claim 9 wherein the height adjustable attachments

comprise a plurality of threaded tie-bars.

10. A machine according to any of the preceding claims, wherein the mould comprises at least an attached half and a removable half and wherein the removable half Is so sized and shaped as to be suitable for use as a demoulder head during demoulding.

1 1. A pressure casting machine substantially as described herein, with reference to and as illustrated by any appropriate combination of the text and/or drawings.

12. A method of pressure casting using a mould comprising at least two portions and an elongate support comprising the steps, in this order, of: casting in a first position,

moving the mould along a linear path along the elongate support to a second position, in use, above the first position,

opening the mould in the second position; and

demoulding in the second position, using a portion of the mould as a demoulder head. 1 !

13. A method of pressure casting according to claim 1 1, wherein the opening of the mould and the demouidlng are accomplished by a single robot arm.

14. A method of pressure casting substantially as described herein, with reference to and as iliustrated by any appropriate combination of the text and/or drawings.