Improved Heat-indicators or Trial-pieces and Stands for use in Pottery and other Kilns.
Year: 1898

page_text: Improved Heat-indicators or Trial-pieces and Stands for use in
Pottery and other Kilns.
We, JOSEPH PETER HOLDCROFT, 19, Park Terrace, Tunstall, Earthenware and
Brick Manufacturer. WILLIE JACKSON, S, Cooper Street, Tunstall, Analytical
Chemist, and ARTHUR TOMKINSON, 4, Woodland Street, Tunstall, Earthenware
Manufacturer, all in the County of Staffordshire, do hereby declare the nature
of, this invention to be as follows:-
-:
This our invention has reference to improved heat-indicating, or trial pieces
for use by potters, brickmakers or other persons for enabling the heat or tem-
perature of kilns or ovens within which clay or earthenware goods are being
fired to be readily controlled or regulated, the object of our said invention being
to make more efficient and reliable heat-indicating or trial pieces. for the purpose
named than those hitherto used.
In carrying this our invention into practice we make a plastic or semi-plastic
mass or compounds of or from earthen silicates and other materials or ingredients
in suitable proportions, which compounds while plastic or semi-plastic we mould
by any suitable means into any suitable sizes, cross-sections and lengths, or we
take such compounds in a dust state and form such lengths by using a suitable
metallic die or dies, such pressed or solidified dust lengths, or plastic or semi-
plastic lengths of compounded ingredients being dried by any suitable artificial
heat, or by the heat of the surrounding atmosphere before being used as heat
indicators in ovens or kilns.
According to the class of goods to be fired we take three or more similar lengths
or sticks of different compound which will soften and bend at different tempera-
tures and place them horizontally or about horizontally at a short distance above
and behind each other upon a suitably shaped moulded or pressed fire-clay
stand so that each end of each stick or length will be supported, one of such.
stands supporting three, or more of such compound lengths or sticks being
sufficient for placing in each trial seggar in such kilns or ovens.
"
On looking through the inspection holes of a kiln or oven at such heat-
indicators or trial pieces within a seggar after firing for some time it can be
readily ascertained if the desired temperature has been attained by reason of the
middle or central portion of the composition lengths or sticks on such fire-clay
stands bending or sagging" down between their supports, as such compound
lengths bend or sag
successively as different or higher temperatures are
reached, thus indicating to the fireman, stoker or other persons in charge the
temperature reached; and whether one or more, or the several fires of such kilns
or ovens require making up or damping down.
66
39
A modified form of fire-clay stands for supporting such sticks or lengths of
compound we make by pressing in the shape of pillars or blocks of suitable height

page_text: with horizontal holes of suitable size and shape through same, so that such lengths
or sticks of compound material may be placed in such holes, and be supported
at, or at about the middle of their length. As the successive temperatures are
reached each end of such compound lengths will bend or fall downwards.
Such fire-clay stands may be moulded, pressed or otherwise made with holes
only partially through same for enabling one end only of each of such compound
lengths to be placed or fitted therein, so that such lengths will project at, or
at about right angles to such stands, and as different temperatures are reached
the unsupported or projecting portion of such lengths or sticks will bend or fall
downwards thus enabling the firemen or persons in charge to ascertain the tem-
perature within such ovens or kilns.
JOHN NEWTON,
Longport, Stoke-on-Trent, Staffs.,
Agent for Applicants.
Improved Heat-indicators or Trial-pieces and Stands for use in
Pottery and other Kilns.
We, JOSEPH PETER HOLDCROFT, 19, Park Terrace, Tunstall, Earthenware and
Brick Manufacturer. WILLIE JACKSON, 8, Cooper Street, Tunstall, Analytical
Chemist, and ARTHUR TOмKINSON, 4, Woodland Street, Tunstall, Earthenware
Manufacturer, all in the County of Staffordshire, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
This our invention has reference to improved heat-indicating. or trial-pieces
and stands therefor for use in pottery, and other kilns, ovens or furnaces within
which clay or earthenware goods or other articles are fired for enabling the heat
or temperature of such kilns or ovens to be readily controlled or regulated, the
object of our said invention being to make more efficient and reliable heat-
indicating or trial-pieces for the purpose named than those, hitherto used.
In carrying this our invention into practice we make heat-indicating com-
positions from felspar, whiting, kaolin, quartz, oxide of iron, boric acid and
carbonate of lead in various proportions according to the temperature such
compositions are desired to attain or soften at, after such ingredients have been
sufficiently powdered or granulated and mixed together by any suitable means
we make same into a plastic or semi-plastic condition by adding water of ordinary
temperature thereto from which we mould, or press by using a suitable die, or
dies determined lengths of any suitable transverse section, or continuous strips
or lengths of such compositions may be first formed by using any suitable
machine or apparatus and afterwards cutting or dividing such strips by any suit-
able means into the requisite lengths, afterwards drying or firing such lengths
to sufficiently harden them without reaching or interfering with their bending
or melting point.
The stands used for supporting such composition sticks or lengths we make of
any suitable shape and size by pressing or moulding of or from fire-clay, gan-
nister or like suitable refractory or heat-resisting material having two or more
horizontal or nearly horizontal curved ledges on or at each of their sides at a
short distance above and behind each other on which ledges we place the ends of
such composition lengths or sticks, each of which composition lengths or sticks

page_text: .
will bend or sag in the middle or un-supported part of their length at a
different temperature.
In order that our said invention may be more readily understood and explained
in detail we have hereunto annexed two sheets of drawings on which letters of
reference are marked.
DESCRIPTION OF DRAWINGS;
Figure 1 represents a front elevation of the form of pressed or moulded fire-
clay, gannister or like suitable refractory or heat-resisting stand we prefer to
use for supporting such heat-indicating lengths or sticks.
Figure 2 is a similar view to Figure 1 shewing in dotted lines the approximate
shape assumed by such composition sticks or trial pieces within a kiln, oven or
furnace on attaining their bending or melting point or temperature.
Figure 3 is a plan view of the stands shewn at Figures 1 and 2 shewing in
dotted lines four lengths or sticks of heat-indicating composition placed thereon,
each of which sticks will soften and "sag" at a different temperature.
Figure 4 represents a side sectional elevation of the stands shewn in the above
Figures taken on the dotted lines A-B of Figures 1 and 2.
Figures 5, 6, 7 and 8 represent transverse sections in which such composition
heat-indicating lengths or sticks may be moulded or pressed by using any suit-
able die or dies, machine or apparatus.
Figure 9 represents a side elevation of another form of fire-clay or like suitable
heat-resisting stand or support.
Figure 10 is an end elevation, and
Figure 11 a plan view respectively of the stand shewn at Figure 9.
On reference to the drawings hereto annexed a represents a fire-clay or like
suitable refractory stand having four horizontal or nearly horizontal ledges bat
each of its sides at a short distance above and behind each other which ledges
support composition lengths or sticks c as shewn in dotted lines at Figure 3, each
of which sticks will bend or sag" in the middle or un-supported part of their
length at a different temperature to or approximately to the shape shewn by
dotted lines at Figure 2.
<<
If fire-clay or like suitable heat-resisting or refractory supports a³ similar to
that shewn at Figures 9, 10 and 11 are used the composition sticks or lengths c
may be supported at the middle of their length as shewn at 3 Figure 9, or one
end only of such sticks which may be slightly tapered may be inserted or fitted
into the holes of such stands as shewn at c Figure 9.
"
According to the class of goods, ceramic-ware, bricks, glass-ware, ceramic-
colours metals, cement or other articles to be fired we take three or more similar
lengths or sticks of different proportions of ingredients of the same composition
which will "sag or bend at different temperatures and place them on a refrac-
tory support or stand in either, of the ways shewn at Figures 3 and 9, one of such
stands with their complement of sticks being sufficient for placing in each trial
seggar in the kiln, oven or furnace used.
Such stands may be larger or smaller for supporting a less or greater number
of such composition or heat-indicating sticks or lengths.
On looking at such heat indicators or trial-pieces after firing for some time it
will be readily seen if the desired temperature has been attained by reason of the
un-supported portion of such composition lengths or sticks "sagging" success-
ively as shewn to or approximately to the dotted lines at Figure 2, or dotted
lines at Figure 9 as different temperatures are reached thus indicating to the
stoker or other person in charge the temperature attained, and whether one or
more of the several fires of such kilns, ovens or furnaces in which such appliances
are used require making up or damping down.
Supposing earthenware goods are to be fired in a Glost Oven the lowest com-
position length or stick would bend or sag" say at 1900°, the top-most stick
"

page_text: say at 2050° and the intermediate sticks (if four sticks are used) at 1950° and
2000° respectively.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is :-
1. The improved form of composition lengths or sticks c made of or from
felspar, whiting, kaolin, quartz, oxide of iron, boric-acid and carbonate of lead
in varying proportions for use in indicating various or different degrees of tem-
perature within kilns, ovens or furnaces used for firing ceramic-ware, bricks,
glass, glass-ware, ceramic-colours, metals, cement or other goods or articles, and
the fire-clay, gannister or the like suitable refractory or heat-resisting stands a
for supporting such composition lengths or sticks in a horizontal or nearly
horizontal position as herein substantially described, set forth and illustrated on
the drawings hereto annexed.
2. The improved form of composition lengths or sticks c made of or from felspar,
whiting, kaolin, quartz, oxide of iron, boric-acid and carbonate of lead in varying
proportions for use in indicating various or different degrees of temperature.
within kilns, ovens or furnaces used for firing ceramic-ware, bricks, glass-ware,
glass, ceramic-colours, metals, cement or other goods or articles, and the fire-clay,
gannister or other like suitable refractory or heat-resisting stands for
supporting such composition lengths or sticks as hercin substantially described,
set forth and illustrated on the drawings hereto annexed.
3. The improved form and transverse sections of composition lengths or
sticks made of or from felspar, whiting, kaolin, quartz, oxide of iron, boric-
acid and carbonate of lead in varying proportions for use in indicating different
or various degrees of temperature within kilns, ovens or furnaces used for firing
various goods or articles and the refractory or heat-resisting stands a, a² for
supporting such composition lengths or sticks in a horizontal or nearly horizontal
position as herein substantially described and set forth.
Dated this 23rd day of November 1898.
JOHN NEWTON,
Longport, Stoke-on-Trent, Staffs.,
Agent for Applicants.