GB2041914A

GB2041914A - Apparatus for Applying Glaze to an Article

Info

Publication number: GB2041914A
Application number: GB8002447A
Authority: GB
Original assignee: Sampson Bridgwood & Son Ltd
Current assignee: Sampson Bridgwood & Son Ltd
Priority date: 1979-01-30
Filing date: 1980-01-24
Publication date: 1980-09-17
Also published as: GB2041914B

Abstract

The invention relates to an apparatus for glazing articles, particularly holloware ceramic articles. A rotary turntable (36) conveys the articles (8) on a plurality of annular metal strips past nozzle arrangements, one for applying glaze on a waterfall principle (50) and the other on a fountain principle. Excess glaze may be blown off the tops of the articles by air passing through the nozzle (56). To prevent accummulation of glaze on the edges of the articles, the turntable (36) is vertically reciprocable and is subjected to abrupt braking in one direction to provide an inertia force. This is preferably achieved by providing the drive shaft (32) for the turntable (36) with an annular cam (64) which moves over a fixed abutment (66). The turntable (36) rotates within a structure (22) for recovering the excess glaze. <IMAGE>

Description

SPECIFICATION Improvements in or Relating to Apparatus for Applying Glaze to an Article The invention is concerned with improvements in or relating to apparatus for applying a coating of glaze or other material to an article and is particularly concerned with apparatus for glazing of holloware ceramic articles such as cups. For ease of description reference will be made hereinafter and in the claims to the use of glaze only.

According to the present invention there is provided apparatus for applying glaze to an article,. said apparatus comprising means for conveying an article past an arrangement for applying glaze or like material to the article and means for effecting reciprocal movement of the conveying means in a substantially vertical direction and braking each movement in one direction in such a manner that inertia prevents any excess glaze remaining on the article.

Preferably the conveying means is a rotary turntable, and the latter may include annular strips of material which are spaced apart radially of the turntable to define through passages.

Upper edges of the annular strips may locate in a plane which slopes downwardly in a radially inward direction.

Preferably also the means for applying glaze comprises a nozzle arrangement for directing the glaze on to an outer surface or outer surfaces of an article on the conveying means. For glazing a holloware article supported in an inverted position on the conveyor means, the nozzle arrangement may include a nozzle for directing the glaze upwardly through the conveying means on to inner surfaces of the article.

Advantageously means are provided for blowing air across the upper, outer surface of an article on the conveyor means, subsequent to the application of the glaze thereto so as to remove any excess glaze from any recess in the upper surface of the article.

The means for effecting reciprocal movement of the conveyor may comprise a central shaft for the turntable which has a cam surface operatively engageable with a fixed member. For example the cam surface may be defined by an annular toothed member.

The apparatus may further include a base defining, beneath the turntable, an angled floor for collecting excess glaze and directing same towards a main reservoir. An auxiliary reservoir may be positioned on the apparatus to provide a suitable pressure head for glaze passing from the auxiliary reservoir to the means for applying the glaze, and the auxiliary reservoir may further comprise a filter and an overflow outlet communicating with the main reservoir.

An embodiment 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 side elevation of a glazing apparatus according to the invention; Fig. 2 is an end elevation of the apparatus of Fig. 1 and; Fig. 3 is a plan view of the apparatus of Figs. 1 and2.

Referring to the drawings, a glazing apparatus particularly for holloware articles such as cups 8, comprises a support structure 10 having a vertical member 12, a pair of outwardly diverging feet members 14 at the lower end of the member 12, a horizontal member 16 at the upper end of the member 12 and extending therefrom vertically above and between the members 14, and, substantially midway along the length of the member 12, a horizontally extending support arm 18 substantially parallel to the member 16. The feet members 14 have rollers 1 5 and mount upwardly extending support legs 20 for a base structure 22 defining a floor 24 angled downwardly with respect to the horizontal from the edge adjacent to one of the feet members 14 towards the opposed edge for a purpose hereinafter described.The floor 24 has an upwardly extending peripheral wall with a funnel 26 at the location of said opposed edge.

Each of the member 16 and the arm 18 mounts at its outer end a bearing assembly 28, 30, respectively for a vertically extending shaft 32. The latter at its upper end operatively engages with a drive assembly 34, located abovethe member 16 and its lower end mounts a turntable 36 for rotation above the floor 24 and within the confines of the peripheral wall.

The turntable 36 has a central substantially conical part 38 provided at its outer periphery with a plurality of radially extending and circumferentially spaced apart support struts 40, the latter mounting a plurality of annular metal strips 42 with edges uppermost, the strips 42 being radially spaced apart to define through passages therebetween. The arrangement is such that the radially outermost and innermost strips have their upper edges extending above the upper edges of the intermediate strips, and the strips lie in a plane sloping downwardly in a radially inward direction.

A main reservoir 44 for the glaze medium is located at that side of the apparatus to which the floor 24 slopes downwardly, the funnel directing excess glaze back into the reservoir 44 for re-use.

An auxiliary reservoir 46 is mounted on the frame structure 10 above the location of the turntable 36 to provide a suitable pressure head for glaze which passes from the reservoir 46 through a filter (not shown) and a first pipe 48 to a nozzle arrangement 40 for applying glaze to upper surfaces of articles, and a second pipe 52 to a nozzle arrangement 54 for applying glaze on to the lower surfaces of holloware articles when the latter are inverted on the turntable 36. Each of the pipes 48, 52, has a section leading downwardly from the reservoir 46 and then a section extending horizontally to respective locations above and below the turntable 36. The nozzle arrangement 50 comprises three nozzles for directing glaze onto the top surface and opposite sides of an article such as a cup 8 when the latter is inverted and positioned on the strips 42.The turntable 36 is arranged for rotation in a direction of arrow A and the glaze is applied by the nozzle arrangement 50 before the inverted cup moves to a location above a nozzle of the arrangement 54 where glaze is applied between adjacent ones of the strips 42 internally of the article. The horizontal portion of the pipe 48 is supported by the arm 18.

After glaze has been applied, each article is moved by the turntable 36 below a further nozzle 56 which is connected by a flexible conduit 58 to a source of compressed air such that air can be blown over the article and, for example in the case of an inverted cup, excess glaze can be removed from the upwardly facing recess therein.

The auxiliary reservoir 46 communicates with the main reservoir 44 by means of a pipe 60 and a pump 47 is provided for passing glaze from the main reservoir 44 to the auxiliary reservoir 46.

Also the auxiliary reservoir 46 has an overflow pipe 62 which communicates with the main reservoir 44.

At its upper end, the shaft 32 mounts an annular cam 64, for example in the form of downwardly projecting saw teeth, the cam 64 being arranged to move over a fixed abutment 66 so as to effect reciprocal movement of the shaft 32, and thus the turntable 36, in a vertical direction with each downward movement being braked abruptly by engagement of the abutment 66 in the saw teeth recesses. This abrupt braking is also therefore applied to the articles on the turntable 36 and, in respect of the articles which have already been glazed, inertia will prevent accumulation of any excess glaze on the lower eges of these articles as the excess glaze will be shaken off to fall on to the floor 24 between the strips 42.

The design of the apparatus is such that, after glazing, the time taken for an article to be moved to a location for removal to a drier is such that flow of glaze has finished and the article can be manually removed by an operator with glaze covered fingers. The use of a rotary turntable enables the one operator to both place unglazed articles in the apparatus and remove the surface dry glazed articles therefrom, and is thus extremely economical. As the conveyor means for the articles, i.e., the turntable, does not require to transfer the articles through a drier no problems are associated with heating of the metal as can be experienced with in-line conveyors which carry articles both through a glazing stage and the drying stage.

The apparatus described enables the use of both the "waterfall" principle and the "fountain" principle in the one device for glazing of holloware articles and the inward slope of the strips on the turntable prevents the articles from moving radially outwardly during operation. The knocking applied to the turntable and thus the articles avoids the necessity of any additional arrangement which would otherwise be necessary to remove glaze which would accumulate at the lower edges of the articles.

It will be appreciated that the nozzle arrangements for applying the glaze may be designed as appropriate in accordance with the articles which are to be glazed and it need not be necessary to provide or use both nozzle arrangements in the one apparatus. The sequence of glazing may also be altered. For example the upper surface of an inverted cup may be first glazed by a waterfall nozzle, the inner surfaces then by a fountain nozzle, the air blow then being effective, and finally glaze applied to the sides.

Also the air blow may not be required depending on the articles which are to be glazed.

Various modifications may be made without departing from the invention. For example the means for effecting reciprocal movement of the turntable may be other than that described, requiring only that knocking effect is available to prevent accumulation of excess glaze. It will be appreciated that the invention is particularly suitable for use with articles of biscuit ware.

Claims

1. Apparatus for applying glaze to an article, said apparatus comprising means for conveying an article past an arrangement for applying glaze or like material to the article and means for effecting reciprocal movement of the conveying means in a substantially vertical direction and braking each movement in one direction in such a manner that inertia prevents any excess glaze remaining on the article.

2. Apparatus according to claim 1, wherein the conveying means is a rotary turntable.

3. Apparatus according to claim 2, wherein the rotary turntable includes annular strips of material which are spaced apart radially of the turntable.

4. Apparatus according to claim 3, wherein upper edges of the annular strips are located in a plane which slopes downwardly in a radially inward direction.

5. Apparatus according to any of the preceding claims, wherein the means for applying glaze comprises a nozzle arrangement for directing the glaze on to an outer surface or outer surface of an article on the conveying means.

6. Apparatus according to claim 5, wherein the nozzle arrangement inciudesa nozzle for directing glaze upwardly through the conveying means.

7. Apparatus according to any of the preceding claims, wherein means are provided for blowing air across a surface of an article on the conveying means.

8. Apparatus according to any of the preceding claims, wherein the means for effecting reciprocal movement of the conveying means comprises a central shaft for the turntable which has a cam surface operatively engageable with a fixed member.

9. Apparatus according to claim 8, wherein the cam surface is defined by an annular toothed member.

10. Apparatus according to any of the preceding claims, including a base defining, beneath the turntable, an angled floor for collecting excess glaze and directing same towards a main reservoir.

1 Apparatus according to claim 10, wherein an auxiliary reservoir is positioned to provide a suitable pressure head for glaze passing from the auxiliary reservoir to the means for applying the glaze.

12. Apparatus according to claim 1 wherein the auxiliary reservoir includes a filter and an overflow outlet communicating with the main reservoir.

13. Apparatus for applying glaze to an article, substantially as hereinbefore described with reference to the accompanying drawings.

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