GB2321615A

GB2321615A - Ware forming apparatus

Info

Publication number: GB2321615A
Application number: GB9702187A
Authority: GB
Inventors: Dennis Podmore; John Michael Victor Burnett; Robert Norman Deakin; John Barrie Turner
Original assignee: British Ceramic Research Ltd
Current assignee: British Ceramic Research Ltd
Priority date: 1997-02-04
Filing date: 1997-02-04
Publication date: 1998-08-05
Also published as: WO1998033633A1; GB9702187D0

Abstract

Ware forming apparatus 10 comprising a plurality of permeable first dies 28, a second die 20, and a ware receiving member 40. An item of clay is shaped between the first and second dies 28, 20 by pressing. The receiving member 40 has substantially the same shape as the second die 20 when the shaped clay 46 on the first die 28 is urged thereagainst and the shaped clay 46 can be released onto the receiving member 40 by blowing a fluid through the first die 28. The shaped clay 46 is released onto the receiving member 40 substantially simultaneously as an item of clay is shaped between the first and second die 28, 20.

Description

WARE FORMING This invention concerns ware forming apparatus and a ware forming method.

To date, for non-circular holloware and flatware pottery items, the only generally accepted forming method has been plastic clay pressing, and more recently also pressure casting. The latter method requires a high capital cost in machinery. This method is also relatively slow with for instance the cycle time for a large single bone china item being one and a half to two minutes, and for earthenware three to four minutes. The first method is also relatively slow, producing only two or three items per minute from a single die. Yields from this process are also generally low being in the order of 60-65%. This low yield is mostly due to strains and distortion occurring during removal of the shaped clay from the dies.

According to the present invention there is provided ware forming apparatus, the apparatus comprising a plurality of permeable first dies, a second die, and a ware receiving member, the first and second dies being such that an item of clay can be shaped therebetween by pressing, the receiving member being such as to substantially have the shape of the second die at least when a piece of shaped clay borne on a first die is urged thereagainst; means being provided for blowing a fluid through a respective first die when same is urged against the receiving member, to release the shaped clay onto the receiving member, the apparatus being arranged such that an item of clay can be shaped between a one of the first dies and the second die substantially simultaneously as a shaped item of clay on a further one of the first dies is released onto the receiving member.

The apparatus preferably includes press means which presses together the respective first and second dies, and also urges the respective further first die on to the receiving member. The press means may comprise a single press.

The first dies are preferably selectively movable between a first position in alignment with the second die, and a second position in alignment with the receiving member. The first dies may be rotatably mounted on the apparatus, or alternatively slidably mounted, to be movable between said first and second positions.

The apparatus preferably comprises means for applying suction through the first dies to hold the shaped clay thereagainst following removal thereagainst of the second die.

The receiving member may be partially or wholly profiled to substantially the same shape as the second die.

The apparatus may be arranged such that a resistive force is applied to the receiving member when a piece of shaped clay formed by a one of the first dies is urged thereagainst, said resistive force being slightly less than the force applied by the fluid being blown through the first die.

A pneumatic cylinder may be provided to apply the resistive force.

Alternatively, a resilient member such as a spring may be provided to apply the resistive force.

The receiving member may be of a resilient material so as to substantially adopt the shape of the second die when a piece of shaped clay carried by a one of the first dies is urged thereagainst. The receiving member is preferably such that when the shaped clay is blown off a one of the first dies, the receiving member is compressed a little further to receive the shaped clay off the die.

The receiving member preferably comprises a block of resilient material of greater thickness than the depth of the shaped clay. The receiving member may be formed such that it returns to substantially its initial shape whilst the shaped clay is thereon, after the first die has been moved away from said member.

The resilient material may comprise a sponge or foamed material, and preferably comprises a plastics material. The receiving member may be shaped to support particular parts of the shaped clay when located thereon. For example, the receiving member may include an upstanding annular projection for supporting the rim of shaped clay flatware. For use with holloware, an upstanding projection may be provided on the receiving member which is locatable within the shaped clay. Said projection may be shaped to substantially conform to the internal profile of the shaped clay.

A plurality of receiving members may be provided such that a shaped item can be carried on a receiving member following release from a one of the first dies.

The apparatus may be arranged such that a receiving member carrying a shaped item is automatically moved away from the second position, and a further empty receiving member is moved to the second position.

The apparatus may comprise a dryer and means for moving the receiving members when carrying shaped items, through the dryer. Means may also be provided for removing shaped items from the receiving members following passage through the dryer. The receiving members may be mounted on an endless conveyor.

The apparatus may comprise means for blowing air through the first and/or second dies following removal of clay therefrom, to condition same.

Means may be provided for detecting when the shaped clay has been blown off a one of the first dies. The detection means may comprise means for sensing a reduction in back pressure in the first die.

The apparatus may be arranged to have at least three first dies, with means for cleaning a one of the first dies substantially simultaneously with shaping an item of clay on another of the first dies, and releasing an item of clay from yet another of the first dies.

The invention also provides a method of forming clayware, the method comprising locating a piece of clay between a permeable first die and a second die, shaping the clay by pressing the first and second dies together, retaining the clay on the first die whilst locating a resilient member against the shaped clay on the opposite thereof to the first die, urging the receiving member against the shaped clay such that at least at this point the receiving member substantially has the shape of the clay to provide a close fit thereagainst, blowing a fluid through the first die to blow the shaped clay thereoff onto the receiving member, the shaped clay being blown off substantially simultaneously as a further piece of clay is being shaped between a further first die and the second die.

Following shaping of the clay, the respective first die is preferably moved between a first position in alignment with the second die, and a second position in alignment with the receiving member. Suction is preferably applied throught the respective first die to hold the shaped clay thereagainst following shaping and prior to location on the receiving member.

A resistive force is preferably applied to the receiving member against the clay, said resistive force being slightly less than the force applied by the fluid being blown through the mould.

Part or all of the shaped clay may be supported by the receiving member following release from a one of the first dies. The shaped clay may be carried on the receiving member following release from a one of the first dies, and the shaped clay may be carried on the receiving member during drying.

Air may be blown through the first and/or second dies following removal of shaped clay therefrom, to condition the dies. The air may be warmed.

The first dies may be cleaned following removal of the shaped clay therefrom, with the cleaning taking place simultaneously with shaping an item of clay on another of the first dies, and releasing an item of clay from yet another of the first dies.

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which: Fig. 1 is a diagrammatic plan view of a first ware forming apparatus according to the invention; Fig. 2 is a diagrammatic side view of the apparatus of Fig. 1; and Figs. 3 and 4 are similar views of a second ware forming apparatus according to the invention.

Figs. 1 and 2 of the drawings show ware forming apparatus 10 suitable for forming for instance non-circular bowls. The apparatus 10 comprises a press 12 with two up-stroke pistons 14,16. The first piston 14 has an upper platen 18 which mounts a lower die 20 of a conventional type used in plastic clay pressing. The second piston 16 has a platen 22.

A swivel plate 24 is pivotally mounted on an axis 26 to an upper part of the press 12. The plate 24 mounts two upper dies 28 suitable for plastic clay pressing. The dies 28 are positioned so as when in alignment to be coaxial respectively with the platens 18,22.

The upper dies 28 are permeable, and means (not shown) is provided for selectively blowing or sucking air therethrough. Appropriate support surfaces 30,32 are provided on the upper part of the press 12 opposite the pistons 14,16.

The apparatus 10 also comprises an endless conveyor 34. The conveyor 34 mounts a plurality of equispaced ware carriers 36. The carriers 36 comprise a base plate 38 upon which is mounted a block 40 of foamed plastics material.

The conveyor 34 is arranged such that the carriers 36 can be located on the platen 22. The conveyor 34 extends from the platen 22 into a dryer 42. The conveyor extends through the dryer 42 and thereout to an unloading station 44.

In use, with the piston 16 lowered as shown in Fig. 2, and the upper dies 28 aligned with the platens 18,22, a piece of clay is located on the lower die 20.

The pistons 14,16 are then raised such that the clay is shaped between the dies 20 and 28. Once shaping has been completed, suction is applied through the respective die 28 and the pistons 14,16 are lowered. The plate 24 is then pivotted such that the upper die 28 carrying shaped clay 46 is now located above the platen 22 upon which a carrier 36 is located.

A further piece of clay is supplied onto the die 20 for shaping with the respective die 28. The pistons 14,16 are again raised for the plate to be shaped as previously. As the piston 16 is raised the shaped clay 46 held on the respective die 28 is brought into contact with the block 40 which will be compressed to adopt substantially the same shape as the die 20. Instead of air being sucked through the die 28, air is now blown therethrough such that the shaped clay 46 is blown onto the block 40. As the shaped clay 46 is blown off the die 28, the block 40 will compress a little more thereby providing an even release of the clay 46 without damage occurring thereto. Once shaping and clay release has been completed, the pistons 14,16 will again be lowered. The conveyor 34 will then move round in the direction shown by the arrow 48 such that the carrier 36 carrying the shaped clay 46 will move towards the dryer 42, whilst an empty carrier 36 will be moved onto the platen 22. Carriers 36 exiting from the dryer 42 reach the unloading station 44 where the dried shaped clay is removed from the respective carrier 36 for subsequent processing. The process continues in this manner with the plate 24 being rotated through 1800 between each clay shaping and shaped clay release step.

Figs. 3 and 4 show ware forming apparatus 50 which is similar to the apparatus 10 in many respects, and similar reference numerals will be used for identical components. In the apparatus 50 a press 52 is provided with a single downward stroking piston 54.

In this instance the upper dies 28 are mounted on a plate 56 which is slidably movable between positions where respectively each upper die 28 is located above the lower die 20. The plate 56 is slidably mounted on a platen 58 mounted on the piston 54 such that the stroke of the piston 54 causes the pressing for shaping and also the urging of the shaped clay 46 onto the carriers 36. This configuration provides for alternate release of shaped clay 46 on to carriers 36 on either side of the press 52 in the loop of the conveyor 34. The shaped clay is urged on to the carriers 36 alternately on either side, the conveyor 34 moving the carriers 36 in the direction of the arrow 48 between each loading, to provide an empty carrier 36 in the required place. Otherwise, the apparatus 50 operates in a similar way to the apparatus 10.

There is thus described ware forming apparatus, and a method of forming ware which provide for considerable advantages. As the shaped clay is received off the upper dies the chance of damage occurring to the shaped clay is greatly reduced. As clay release takes place simultaneously with shaping this provides for a much faster operation. Apparatus according to the present invention is readily suitable for automation thereby reducing operative costs.

Various modifications may be made without departing from the scope of the invention. For example, the blocks on the ware carriers may be shaped to support particular parts of the shaped clay such as annular projections for supporting rims. For use with holloware, an upstanding projection may be provided locatable within the shaped clay, and perhaps to conform with the internal profile of the shaped clay.

As an alternative, the carriers may mount a rigid member which corresponds in shape to the lower die. In this instance it has been found particularly advantageous to include an arrangement to provide a resistive force to the underside of the carrier which is slightly less than the force applied to the air being blown through the die. With this arrangement, as the shaped clay is blown off the die the carrier will drop slightly thereby providing even release of the shaped clay without damage thereto, as is provided by the resilient material. The resistive force may be provided by a pneumatic cylinder, or resilient member such as a spring located beneath the carriers. A suitable structure could be provided in each carrier, or a structure could be provided beneath the appropriate location where the carrier will be sited during clay release.

Fluid, and particularly warm air may be blown through the lower and/or upper dies when clay is not located therein, to condition the dies. Apparatus could be provided with more than two upper dies. For instance, an arrangement could be provided with three upper dies, whereby a one of the upper dies is simultaneously cleaned whilst the other two dies respectively shape the clay and provide for release of shaped clay. Other arrangements for moving the upper dies between the respective positions could be used.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or-combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1. Ware forming apparatus, the apparatus comprising a plurality of permeable first dies, a second die, and a ware receiving member, the first and second dies being such that an item of clay can be shaped therebetween by pressing, the receiving member being such as to substantially have the shape of the second die at least when a piece of shaped clay borne on a first die is urged thereagainst; means being provided for blowing a fluid through a respective first die when same is urged against the receiving member, to release the shaped clay onto the receiving member, the apparatus being arranged such that an item of clay can be shaped between a one of the first dies and the second die substantially simultaneously as a shaped item of clay on a further one of the first dies is released onto the receiving member.

2. An apparatus according to claim 1, wherein the apparatus includes press means which presses together the respective first and second dies.

3. An apparatus according to claim 2, wherein the press means urges the respective further first die on to the receiving member.

4. An apparatus according to claim 2 or 3, wherein the press means comprises a single press.

5. An apparatus according to any of claims 1 to 4, wherein the first dies are selectively movable between a first position in alignment with the second die, and a second position in alignment with the receiving member.

6. An apparatus according to claim 5, wherein the first dies are rotatably mounted on the apparatus to be movable between said first and second positions.

7. An apparatus according to claim 5, wherein the first dies are slidably mounted on the apparatus to be movable between said first and second positions.

8. An apparatus according to any of the preceding claims, wherein the apparatus comprises means for applying suction through the first dies to hold the shaped clay thereagainst following removal thereagainst of the second die.

9. An apparatus according to any of the preceding claims, wherein the receiving member is partially profiled to substantially the same shape as the second die.

10. An apparatus according to any of claims 1 to 8, wherein the receiving member is wholly profiled to substantially the same shape as the second die.

11. An apparatus according to any of the preceding claims, wherein the apparatus is arranged such that a resistive force is applied to the receiving member when a piece of shaped clay formed by a one of the first dies is urged thereagainst.

12. An apparatus according to claim 11, wherein said resistive force is slightly less than the force applied by the fluid being blown through the first die.

13. An apparatus according to claim 11 or 12, wherein a pneumatic cylinder is provided to apply the resistive force.

14. An apparatus according to claim 11 or 12, wherein a resilient member such as a spring is provided to apply the resistive force.

15. An apparatus according to any of the preceding claims, wherein the receiving member is of a resilient material so as to substantially adopt the shape of the second die when a piece of shaped clay carried by a one of the first dies is urged thereagainst.

16. An apparatus according to claim 15, wherein the receiving member is such that when the shaped clay is blown off a one of the first dies, the receiving member is compressed a little further to receive the shaped clay off the die.

17. An apparatus according to claim 15 or 16, wherein the receiving member comprises a block of resilient material of greater thickness than the depth of the shaped clay.

18. An apparatus according to any of claims 15 to 17, wherein the receiving member is formed such that it returns to substantially its initial shape whilst the shaped clay is thereon, after the first die has been moved away from said member.

19. An apparatus according to any of claims 15 to 18, wherein the resilient material comprises a sponge.

20. An apparatus according to any of claims 15 to 18, wherein the resilient material comprises a foamed material.

21. An apparatus according to claim 19 or 20, wherein the resilient material also comprises a plastics material.

22. An apparatus according to any of the preceding claims, wherein the receiving member is shaped to support particular parts of the shaped clay when located thereon.

23. An apparatus according to any of the preceding claims, wherein the receiving member may include an upstanding annular projection for supporting the rim of shaped clay flatware.

24. An apparatus according to any of the preceding claims, wherein an upstanding projection may be provided on the receiving member which is locatable within the shaped clay, for use with holloware.

25. An apparatus according to claim 24, wherein the projection is shaped to substantially conform to the internal profile of the shaped clay.

26. An apparatus according to any of the preceding claims, wherein a plurality of receiving members are provided such that a shaped item can be carried on a receiving member following release from a one of the first dies.

27. An apparatus according to any of the preceding claims, wherein the apparatus is arranged such that a receiving member carrying a shaped item is automatically moved away from the second position, and a further empty receiving member is moved to the second position.

28. An apparatus according to any of the preceding claims, wherein the apparatus comprises a dryer and means for moving the receiving members when carrying shaped items, through the dryer.

29. An apparatus according to claim 28, wherein means are provided for removing shaped items from the receiving members following passage through the dryer.

30. An apparatus according to any of the preceding claims, wherein the receiving members are mounted on an endless conveyor.

31. An apparatus according to any of the preceding claims, wherein the apparatus comprises means for blowing air through the first and/or second dies following removal of clay therefrom, to condition same.

32. An apparatus according to any of the preceding claims, wherein means are provided for detecting when the shaped clay has been blown off a one of the first dies.

33. An apparatus according to claim 32, wherein the detection means comprises means for sensing a reduction in back pressure in the first die.

34. An apparatus according to any of the preceding claims, wherein the apparatus is arranged to have at least three first dies, with means for cleaning a one of the first dies substantially simultaneously with shaping an item of clay on another of the first dies, and releasing an item of clay from yet another of the first dies.

35. A method of forming clayware, the method comprising locating a piece of clay between a permeable first die and a second die, shaping the clay by pressing the first and second dies together, retaining the clay on the first die whilst locating a resilient member against the shaped clay on the opposite thereof to the first die, urging the receiving member against the shaped clay such that at least at this point the receiving member substantially has the shape of the clay to provide a close fit thereagainst, blowing a fluid through the first die to blow the shaped clay thereoff onto the receiving member, the shaped clay being blown off substantially simultaneously as a further piece of clay is being shaped between a further first die and the second die.

36. A method according to claim 35, wherein the respective first die is moved, following shaping of the clay, between a first position in alignment with the second die, and a second position in alignment with the receiving member.

37. A method according to claim 35 or 36, wherein suction is applied through the respective first die to hold the shaped clay thereagainst following shaping and prior to location on the receiving member.

38. A method according to any of claims 35 to 37, wherein a resistive force is applied to the receiving member against the clay.

39. A method according to claim 38, wherein said resistive force is slightly less than the force applied by the fluid being blown through the mould.

40. A method according to any of claims 35 to 39, wherein part or all of the shaped clay is supported by the receiving member following release from a one of the first dies.

41. A method according to claim 40, wherein the shaped clay is carried on the receiving member following release from a one of the first dies.

42. A method according to claim 40 or 41, wherein the shaped clay is carried on the receiving member during drying.

43. A method according to any of claims 35 to 42, wherein air is blown through the first and/or second dies following removal of shaped clay therefrom, to condition the dies.

44. A method according to claim 43, wherein the air is warmed.

45. A method according to any of claims 35 to 44, wherein the first dies are cleaned following removal of the shaped clay therefrom.

46. A method according to claim 45, wherein the cleaning takes place simultaneously with shaping an item of clay on another of the first dies, and releasing an item of clay from yet another of the first dies.

47. Ware forming apparatus substantially as herein described with reference to Figs. 1 and 2 of the accompanying drawings.

48. Ware forming apparatus substantially as herein described with reference to Figs. 3 and 4 of the accompanying drawings.

49. A method of forming clayware substantially as herein described with reference to Figs. 1 and 2 of the accompanying drawings.

50. A method of forming clayware substantially as herein described with reference to Figs. 3 and 4 of the accompanying drawings.

51. Any novel subject matter or combination including novel subject matter disclosed, whether or not within the scope of or relating to the same invention as any of the preceding claims.