GB2073168A - Method of making pottery and tile for use therein - Google Patents

Abstract

A method of forming pottery with a foot-ring comprises throwing a pottery article 9 on a rotating tile 1 wherein the tile has a raised circular central portion 2 having its periphery defined by an edge portion 3 around which the foot-ring 8 is formed; the tile 1 for producing pottery article 9 having a foot-ring 8 of a predetermined thickness has a raised circular central portion 2 on an upper surface 4 having its periphery defined by an edge portion 3 and circumferentially extending indicator means 10 substantially concentric with said circular central portion 2 and in proximity to but at a predetermined spacing from the edge portion 3 corresponding to the predetermined thickness of the foot-ring 8 of said pottery article 9. <IMAGE>

Description

SPECIFICATION Method of making pottery and tile for use therein The present invention relates to a method of making a pottery article with a foot-ring and a support tile for use in the method.

Conventionally such pottery is first "thrown" on a square flat tile held in a rubber collar on a potter's wheel head and allowed to dry thereon till it reaches a leather-hard condition. The pot is then removed from the tile and rotated in an inverted condition whilst the base now uppermost is shaped to the required profile by hand in conventional manner.

In alternative processes the "jolly" and "jigger" machines have rotating moulds. In these processes plastic clay is introduced onto or into the male or female mould and the exposed surface shaped with a profile tool which includes a footring while the mould is rotated. The mould is normally made in one section but on occasions two or more sections or "parts" may be used.

These are separated after the pot has hardened.

The "slip cast" technique again uses moulds into which liquid clay is poured. The absorbent plaster of paris mould allows for the making of a skin or thickness of stiffer clay on the walls of its mould.

Excess slip is then removed and the article allowed to dry. Then finally the article is removed from the mould.

Naturally during the drying stage in both processes the relatively expansive mould is unavailable for further use.

It is an object of the present invention to provide an improved method which is more convenient and economic.

The present invention provides a method of forming pottery with a foot-ring which method comprises throwing a pottery article on a rotating tile wherein the tile has a raised circular central portion having its periphery defined by an edge portion around which the foot-ring is formed.

With this invention it will be appreciated that the foot-ring on a pottery article is produced substantially automatically in the course of a substantially conventional throwing operation.

Advantageously circumferentially extending indicator means substantially concentric with the circular central portion are provided in proximity to but spaced from said edge portion, for defining the outer edge of the foot and the method includes the step of forming the outer bottom edge of the pot into a foot-ring whose outermost edge is in line with said indicator means. Suitable indicator means includes grooves or further step portions and may be continuous (circular) or discontinuous, e.g. a plurality of indentations arranged around a circle.

In a further aspect the invention provides a tile for use in the method of the invention for producing a pottery article having a foot-ring of a predetermined thickness wherein the tile has a raised circular central portion on an upper surface having its periphery defined by an edge portion and circumferentially extending indicator means substantially concentric with said circular central portion and in proximity to but at a predetermined spacing from the edge portion corresponding to the predetermined thickness of the foot-ring of said pottery article.

Further preferred features of the invention will appear from the following description given by way of example of one embodiment of the invention illustrated with reference to the accompanying drawings in which: Figure 1 is a partial section view of a pot formed on a first tile of the invention; and Figure 2 is a corresponding view of a second tile.

In Figure 1 is shown a tile 1 which may be square or round or indeed any other polygonal shape and which has a circular raised central portion 2. This raised portion 2 need not be centred on the geometrical centre of the tile though normally this would be most convenient.

The outer periphery of the raised portion 2 is defined by an edge portion 3 comprising an upwardly-extending surface 4 having a lower edge 5 at the junction of said upwardly extending surface 4 with an adjacent generally flat annular surface 6 which serves as a support for the base 7 of the foot-ring 8 of a pottery article 9 to be made on the tile 1. The outer edge of said annular surface 6 is defined by indicator means in the form of a step 10 in Figure 1, and a groove 11 in Figure 2.

The pottery article 9 is "thrown" on the tile 1 in substantially conventional manner as on flat tiles though of course taking care to centre it on the raised portion 2. In order to ensure that the tile has itself been first correctly centred on the wheel head - an essential prerequisite for correct operation -- the underside of the tile 1 may be provided with location means comprising a projection or recess engageable with a complementary formation on the wheel head (not shown).

The foot-ring 8 is formed by working the clay, which will initially be made to extend out beyond the indicator means 10, 11 with a thumb, finger or other implement, conveniently a suitably profiled tool (not shown) mounted on the end of an articulated arm so as to be supported above the wheel head, until the outer edge of the foot-ring 8 is substantially in line with the step 10 or groove 11.

The finished article 9 is left to stand on the tile 1 to dry in the normal way prior to firing and further processing. This is quite acceptable since such a tile can readily be mass-produced and would be much cheaper than a mould for the whole article. If the upwardly extending surface 4 of the edge portion 3 is inclined inwardly away from its lower edge 5 then as the article 9 dries and shrinks slightly it will ride up on the inclined surface 4 rising away from the annular surface.

This has the advantage that the article 9 may be very readily removed from the tile 1 after drying.

As may be seen from Figure 2 the raised portion 2 may be substantially flat with the edge portion 3 forming a distinct step at its periphery.

Alternatively the raised portion 2 and edge portion 3 may both be part of a substantially continuous dome-shaped formation as shown in Figure 1.

Naturally other shapes are also possible without departing from the scope of the invention.

The tile 1 may be made of any substantially rigid material including plastics, rnetal or ceramic though a water-absorbent material such as plaster of paris, teracotta, wood or unglazed ceramic (biscuit tile) is to be preferred as this accelerates drying of the pottery.

Conveniently the tile may also be provided with a guide means of a similar nature to the above described indicator means and concentric therewith but spaced outwardly therefrom. These guide means serve as a guide to the pottery thrower as to how far he is from the indicator means during the course of the formation of the foot-ring.

A particularly convenient method of holding a tile of the invention on a wheelhead and ensuring its correct location is by means of a rubber tile batt such as that produced by the Podmore Company.

This comprises a rubber or similar material cover which fits snugly over and around the wheelhead and has a recessed top surface into which the tile fits snugly. By this means the position of the tile on the wheelhead may be closely predetermined.

Claims (2)

1. A method of forming pottery with a foot-ring which method comprises throwing a pottery article on a rotating tile wherein the tile has a raised circular central portion having its periphery defined by an edge portion around which the footring is formed.

2. A tile for use in the method of the invention for producing a pottery article having a foot-ring of a predetermined thickness wherein the tile has a raised circular central portion on an upper surface having its periphery defined by an edge portion and circumferentially extending indicator means substantially concentric with said circular central portion and in proximity to but at a predetermined spacing from the edge portion corresponding to the predetermined thickness of the foot-ring of said pottery article.