GB2311979A

GB2311979A - Turning ceramic ware

Info

Publication number: GB2311979A
Application number: GB9607372A
Authority: GB
Inventors: David Kenneth Hulse
Original assignee: Royal Doulton UK Ltd
Current assignee: Royal Doulton UK Ltd
Priority date: 1996-04-09
Filing date: 1996-04-09
Publication date: 1997-10-15
Anticipated expiration: 2016-04-09
Also published as: GB2311979B; GB9607372D0

Abstract

A method and apparatus for turning articles 20 of ceramic flatware or holloware comprises delivery means 21, 22 for delivering the articles in sequence at a predetermined delivery speed and in closely spaced relation to a turning mechanism comprising opposed conveyor members 15 adapted to grip the foot and rim of each article in turn, turn the gripped article through 180{ and release the article in an inverted position, there being discharge means 23, 24 for withdrawing the turned articles from the turning mechanism, and drive means, eg motor and roller (8, 9, Figure 1), operable to drive the turning mechanism at a speed greater than the delivery speed. Preferably the drive means drives the turning mechanism between 25% and 50% faster than the delivery means. The discharge means is preferably driven at a speed at least equal to the delivery speed but less than the speed of the turning mechanism. The conveyor members may comprise upper and lower runs of single belt 15 entrained around upper and lower guide rollers (9 - 12, Fig 1). The undersides of the flatware or holloware may have a glaze applied thereto after turning through 180{. The spacing apart of the discharged ware is preferably reduced compared with the delivery spacing.

Description

METHOD AND APPARATUS FOR TURNING CERAMIC WARE This invention relates to a method and apparatus for use in turning ceramic articles.

Ceramic articles such as plates, saucers and the like which are glazed on their upper and lower surfaces require to be turned during the glazing process to enable glaze to be applied to each surface in turn. Traditionally turning of such articles has been effected by hand. More recently it has been proposed to turn the articles mechanically. In co-pending Application No. 9505758 the articles are gripped by the foot and rim between upper and lower belt members which are then rotated through 1800 to invert the article and moved apart to release the article in the inverted position.

Due to the weight of the articles problems can arise in gripping the article sufficiently firmly to avoid them from slipping out from between the belt members which invariably results in breakage. ln FarticcIclr the spacing of the articles requires to be such that the belt members can move together between adjacent articles to provide a sufficiently strong gripping or clamping action.

It is an object of the present invention to provide an improved form of apparatus of this general kind.

According to one aspect of the invention there is provided a method of turning particles of ceramic flatware or holloware by means of a turning mechanism operable to grip the foot and rim of each article between upper ahd lower belt members, rotate the article through 1800 and release thpiiverted article1 the method comprising delivering the articles to the turning mechanism at a predetermined delivery speed and in closely spaced relation, and moving the articles through the turning mechanism at a speed greater than the delivery speed.

Preferably the articles are withdrawn from the turning mechanism at a speed not less than the delivery speed.

The invention also provides apparatus for turning articles of ceramic flatware or holloware comprising means for delivering the articles to a turning mechanism at a predetermined delivery speed and in closely spaced relation1 opposed conveyor members for gripping the foot and rim of each article, turning the gripped article through 1800 and releasing the article in an inverted position, and discharge means for withdrawing the turned articles from the turning mechanism, the turning mechanism being driven at a speed greater than the delivery speed.

Preferably said turning mechanism is driven at least 25% and preferably 50% faster than the delivery speed.

Preferably the speed of operation of said discharge means is at leash equal to the delivery speed and preferably slightly faster than the delivery speed.

Said conveyor members preferably comprise adjacent runs of a single conveyor entrained over upper and lower sets of guide members, each of said runs moving from one to the other set of guide members following said rotation.

Preferably also means is provided to vary the distance between said adjacent runs of the conveyor to adapt the apparatus for handling different articles.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a side elevation of one form of apparatus according to the invention; and Fig. 2 is a plan view of the apparatus shown in Fig. 1 with the upper section of the belt omitted for clarity.

Referring to the drawings, the apparatus comprises a frame 5 supported on adjustable feet 6 and provided with a bracket 7 on which a drive motor 8 is supported. A drive roller 9 is rotatably mounted on the frame 5 and operatively connected to the motor 8. A lower idler roller 10 is rotatably mounted on the frame 5 and a pair of upper idler rollers 11 and 12 are rotatably mounted on arms 13 in positions above the drive roller 9 and idler roller 10.

A conveyor member in the form of a belt 15 is entrained round the drive and idler rollers and around a tensioning roller 16. From the roller 16 the belt moves in the direction of arrow 'A' to the idler roller 10. It then travels in the direction of arrow 'B' towards the right hand end of the machine as shown in title drawings. During this travel the belt is rotated though 1800 and is then entrained round the idler roller 11 and travels in the direction of arrow 'C' to the idler roller 12. After travelling round the roller 12 the belt again travels in the direction of arrow 'B' in a position above and spaced from the section of the belt leaving the roller 10. The section leaving roller 12 is then rotated through 1800, entrained round the drive roller 9 and returns in the direction of arrow 'D' to the tensioning roller 16.

Thus two sections of the belt travel in the same direction between the rollers 10.12 and 9,11 and are rotated through 1800 in the same direction so that thef remain parallel to one another, but the section which is uppermost when leaving the roller 12 is lowermost when it reaches the roller 9 and the section which is lowermost when leaving the roller 10 becomes uppermost when it reaches the roller 11.

Plates 20 or other articles of ceramic flatware are delivered to the turning apparatus by a delivery conveyor 21 and intermediate conveyor 22, both driven at the same speed, and are discharged from the turning apparatus on to a discharge conveyor 23 via an intermediate conveyor 24 driven at the same speed as the discharge conveyor.

In use of the apparatus, plates or other articles of flatware are delivered to the apparatus from the conveyors 21 and 22 in the direction of arrow 'B' on to the upper surface of the lower section of the belt 15. On delivery the plate is in an inverted position so that the rim of the plate is supported on the upper surface of the lower section of the belt. The under surface of the upper section of the belt 15 then moves into contact with the foot of the plate and as the plate moves from left to right the belts twist through 180" thereby turning the plate to an upright position. Towards the discharge or right hand end of the apparatus the then upper and lower sections of the belt move apart thereby leaving the plate supported by its foot on the upper surface of the lower section of the belt from which it is discharged on to the conveyors 24 and 23 and transported away from the turning apparatus in the direction of arrow 'C' for further processing.

As best seen in Fig. 2, the plates 20 are spaced relatively close together on delivery to the turning apparatus, the distance between them in practice being as little as 5mm. If the plates are maintained at this spacing during movement through the turning apparatus, the proximity of each plate to the next reduces the clamping pressure applied by the adjacent upper and lower sections of the belt 15 to the plates with the result that the plates slip from between the belt and are invariably broken. To avoid this the belt 15 is driven at increased speed relative to the speed at which the plates are delivered to the turning apparatus thereby increasing the spacing between the plates in the turning apparatus and hence the gripping force applied to the plates by the belt 15. Preferably the speed of movement of the belt 15 is at least 1.25 and preferably 1.5 times greater than the delivery speed, resulting in an increase in the spacing of the plates to about 100mm.

When the plates are discharged from the turning apparatus the spacing between them is preferably reduced. For this purpose the discharge and intermediate conveyors are preferably driven at a lower speed then the belt ] 5.

Where the plates are closely spaced on delivery to the turning apparatus, as in Fig. 2, the discharge speed must not be less than the delivery speed. Preferably the discharge speed is slightly greather than the delivery speed to space the plates slightly further apart on discharge than delivery to allow for slight differences in movement of the plates as they decelerate on the conveyor 24. In a typical installation the plates may be spaced apart by about 15mum following discharge. However if the plates are relatively widely spaced on delivery, the discharge speed could be less than the delivery speed to reduce the spacing following discharge. There is no upper limit on the discharge speed which depends on the desired spacing between the discharged plates or other articles.

It will be appreciated that the belt 15 contacts the plate only at four zones, that is at diametrically opposed zones on the foot and at diametrically opposed zones on the rim. This will result in removal of some glaze from the foot but the foot is subsequently wiped clear of glaze in any event and hence removal of glaze from the foot during flirting of the plate is not detrimental.

With regard to the rim, the belt will contact the upper surface of the plate adjacent the rim, but only the underside of the plate has been glazed when turning takes place and hence there is no interference with the glazed underside of the rim and glazing of the upper surfaces is effected subsequently after the turned plate has been discharged from the apparatus.

To enable adjustment of the apparatus to handle different articles, such as saucers or bowls, the arms 13 on which the idler rollers 11 and 12 are mounted are pivotally connected to a fixed support 18 and may be angularly adjusted to raise or lower the rollers 11 and 12 relative to the rollers 9 and 10.

This alters the distance between the adjacent belt sections which grip the articles to suit articles of different depth. To assist in tracking of the belts, the roller 9-12 are each provided with a central groove engaged by a projecting rib on the undersurface of the belt. The axis of the drive roller 9 is also inclined relative to the normal to the direction of belt movement to further resist the tendancy of the belt to disengage from the rollers.

The arrangement described enables automatic turning of partly glazed plates or other articles of flat or holloware in a simple and effective manner. By gripping the article only in the region of the rim and foot, undesirable interference with already glazed areas is avoided. By virtue of the increase in speed of movement of the belt compared with the speed of the delivery and discharge conveyors resulting in increased spacing of the articles, the operation is more consistent in handling and less liable to dropping and breakage than hitherto.

Various modifications may be made without departing from the invention. For example the belts may be provided with a variety of alternative surfaces to contact the ware and alternative means of driving the belts and of delivering and discharging the ware to and from the apparatus may be employed.

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

Qaims:-

1. A method of turning articles of ceramic flatware or holloware by means of a turning mechanism operable to grip the foot and rim of each article between upper and lower belt members, rotate the article through 180C and release the inverted article, the method comprising delivering the articles to the turning mechanism at a predetermined delivery speed and in closely spaced relation, and moving the articles through the turning mechanism in sequence at a speed greater than said delivery speed, whereby the spacing between adjacent articles moving through said turning mechanism is greater than the spacing between the articles on delivery to the turning mechanism.

2. A method according to claim 1 wherein the speed of movement of articles through said turning mechanism is between 25% and 50% faster than said delivery speed.

3. A method according to claim 1 or 2 wherein the speed of operation of said discharge means is at least equal to said delivery speed.

4. A method according to claim 3 wherein the speed of operation of said discharge means is greater than said delivery speed but less than the speed of movement of the artides through said turning mechanism.

5. A method of turning articles of ceramic flatware or holloware substantially as hereinbefore described with reference to the accompanying drawings.

6. A method of glazing articles of ceramic flatware or holloware comprising applying a glaze medium to the undersides of the articles, turning the articles by the method according to any of claims 1 to 5 and applying a glaze medium to the upper surfaces of the articles after turning.

7. A method of glazing articles of ceramic flatware or holloware substantially as hereinbefore described.

8. Apparatus for turning articles of ceramic flatware or holloware comprising delivery means for delivering the articles in sequence at a predetermined delivery speed and in closely spaced relation to a turning mechanism comprising opposed conveyor members adapted to grip the foot and rim of each article in turn, turn the gripped article through 1800 and release the article in an inverted position, discharge means for withdrawing the turned articles from the turning mechanism, and drive means operable to drive the turning mechanism at a speed greater than said delivery speed.

9. Apparatus according to claim 8 wherein said drive means is operable to drive said turning mechanism between 25% and 50% faster than said delivery means.

10. Apparatus according to claim 8 or 9 including further drive means operable to drive said discharge means at a speed at least equal to said delivery speed.

11. Apparatus according to claim 10 wherein said further drive means is operable to drive said discharge means at a speed greater than the speed of said delivery means but less than the speed of said turning mechanism.

12. Apparatus according to any of claims 8 to 11 wherein said conveyor members comprise adjacent runs of a single conveyor entrained over upper and lower sets of guide members, each of said runs moving from one to the other set of guide members following said rotation.

13. Apparatus according to any of claims 8 to 12 including means to vary the spacing between said upper and lower belt members to adapt the apparatus for handling of different articles.

14. Apparatus for turning articles of ceramic flatware or holloware substantially as hereinbefore described with reference to the accompanying drawings.

15. Apparatus for glazing articles of ceramic flatware or holloware comprising means for applying a glaze medium to the undersides of the articles, turning apparatus according to any of claims 8 to 14 operable to invert the articles after application of said glaze medium to the undersides thereof, and means for applying a glaze medium to the upper surfaces of the articles after turnIng.

16. Apparatus for glazing artides of ceramic flatware or holloware substantially as hereinbefore described.

17. 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.