Improvements in the Glazing and Enamelling of Heavy Earthenware and other Goods, and in Apparatus to be employed therefor.
Year: 1893

page_text: Date of Application, 29th Mar., 1893
Complete Specification Left, 28th Dec., 1893-Accepted, 10th Feb 1894
PROVISIONAL SPECIFICATION.
Improvements in the Glazing and Enamelling of Heavy Earthenware
and other Goods, and in Apparatus to be employed therefor.
I, THOMAS WILLIAM TWYFORD, of Cliffe Vale Pottery, Hanley, in the County
of Stafford, Manufacturing Sanitary Potter, do hereby declare the nature of this
invention to be as follows:-
This invention relates to a process or means of glazing and enamelling heavy or
cumbersome earthenware and other goods, and consists primarily in applying the
glaze or enamel in the form of spray, through the intervention, or by the aid, of a
blast or an equivalent medium, and further, in the employment of an apparatus to
be used in the application of the said glaze or enamel blast.
Small articles are now readily glazed or enamelled, as they admit of being easily
immersed in a mixture of silicious matter and water, commonly known as potters
glaze, or in enamel, from the fact that there is no difficulty in taking hold of the
said articles, and passing them under the coating liquid, and then setting the same
up to drain.
Sometimes in large articles, the glaze or enamel is applied with a camel hair
brush by one, two or more operatives at a time, and if the article being glazed or
coated happens to be large and cumbersome, then the application has to be made very
quickly, and followed up closely to prevent the edges, which set rapidly, being
overlaid.
By my invention a perfectly uniform film of glaze or enamel is applied through
the medium of my improved glaze or enamel blast.
Thus, in carrying out my invention in connection with glazing I take an
apparatus as hereinafter described, fitted with combined blast and glaze passages or
nozzles, and with the glaze passage terminating at a point in advance of the blast
nozzle, so that the glaze, coming within the path of the blast, is converted into
spray, and deposited or applied upon the sides or surfaces of an earthenware
article to be glazed.
The application of the spray is performed gradually, until the workman, by his
knowledge, knows that he has deposited the necessary film to form an even and
uniform surface, when the same is fired or fused by the application of heat in a
glazing kiln.
.
Thus the workman moves the apparatus gradually from one place to another
until the whole surface has been properly coated. Then the article so treated is
conveyed to a kiln and fired.
The apparatus may consist of two lengths of tubing, converging to a common
centre, one for the conveyance of the liquid glaze, and the other for the blast. The
tail ends or after parts of the tubings are preferably fitted with flexible tubings,
wherethrough the blast and glaze are forced.
The delivery ends may be ordinary spray nozzles, or the glaze when delivered
under blast carriage, may be made to impinge upon a plate, and by its velocity,
rebound in the form of spray onto the article under treatment, and further, the
liquid glaze-blast may be applied by making one passage of the apparatus lie
within the axis of the other passage, alike unto a blowpipe apparatus.
In addition to applying my invention to glazing, the same is equally applicable
to the enamelling of fireclay, stoneware, heavy and cumbersome iron goods, and the
enamel is applied in a color or white, according to the color of the article under
treatment.

page_text: Thus, assuming the article under treatment to be white, I may prefer to use the
enamel colored, so as to show the operator how the application proceeds. If
colored, then he may apply white.
Dated this 28th day of March 1893.
THOMAS WILLIAM TWYFORD,
By Henry Skerrett,
Agent for Applicant.
Improvements in the Glazing and Enamelling of Heavy Earthenware
and other Goods, and in Apparatus to be employed therefor.
I, THOMAS WILLIAM TWYFORD, of Cliffe Vale Pottery, Hanley, in the County
of Stafford, Manufacturing Sanitary Potter, 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 invention relates to a process or means of glazing and enamelling heavy or
cumbersome earthenware and other goods, and consists primarily in applying the
glaze or enamel in the form of spray, through the intervention, or by the aid, of a.
blast or a equivalent medium, and further, in the employment of an apparatus to
be used in the application of the said glaze or enamel blast.
Small articles are now readily glazed or enamelled as they admit of being easily
immersed in a mixture of silicious matter and water commonly known as potters
glaze, or in enamel, from the fact that there is no difficulty in taking hold of the,
said articles, and passing them under the coating liquid, and then setting the same
up to drain, but this is a very difficult process in large articles, as the glaze or
enamel has to be applied with a camel hair brush by one, two or more operatives at
a time, and if the article being glazed or coated happens to be large and cumber-
some, then the application has to be made very quickly, and followed up closely to
prevent the edges, which set rapidly, being overlaid.
By my invention a perfectly uniform film of glaze or enamel is applied through
the medium of my improved glazed or enamel blast.
Thus, in carrying out my invention in connection with glazing I take an
apparatus as hereinafter described, fitted with combined blast and glaze passages or
nozzles, and with the glaze passage terminating at a point slightly in advance of
the blast nozzle, so that the glaze, coming within the path of the blast, is converted
into spray, and deposited or applied upon the sides or surfaces of an earthenware
article to be glazed.
The application of the spray is performed gradually, until the workman, by his
knowledge, knows that he has deposited sufficient glaze spray to form an even and
uniform surface when the same is fired or fused by the application of heat in a
glazing kiln.
Thus the workman moves the apparatus gradually from one place to another
until the whole surface has been properly coated. Then the article so treated is
conveyed to a kiln and fired.
The apparatus may consist of two lengths of tubing, converging to a common
centre, one for the conveyance of the liquid glaze, and the other for the blast.
The tail ends or after parts of the tubings are preferably fitted with flexible
tubings, wherethrough the blast and glaze are forced.
The delivery ends may be ordinary spray nozzles, or the glaze when delivered
under blast carriage, may be made to impinge upon a plate, and by its velocity,
rebound in the form of spray onto the article under treatment, and further, the
liquid glaze-blast may be applied by making one passage of the apparatus lie
within the axis of the other passage, alike unto a blowpipe apparatus,

page_text: In addition to applying my invention to glazing, the same is equally applicable
to the enamelling of fireclay, stoneware and heavy and cumbersome iron goods,
and the enamel is applied in a color or white, according to the color of the article
under treatment.
Thus assuming the article under treatment to be white I may prefer to use the
enamel colored, so as to show the operator how the application proceeds. If
colored, then he may apply white.
Figure 1 of the accompanying drawings represents in longitudinal vertical
section an enamel or glaze spray blast apparatus constructed according to my
invention.
The said apparatus consists of two tubes or passages, through which liquid glaze
and the air blast respectively pass, and which liquid glaze is converted into spray
by being delivered within the path of the blast.
Figure 2 represents an underside plan of the said apparatus showing the spread
out or fan shaped end of the blast nozzle.
Figure 3 shows a front view of the apparatus.
Figure 4 represents the apparatus employed in my process of glazing or
enamelling in operation.
a is a delivery pipe or passage for the conveyance of liquid glaze or enamel,
a¹ is the delivery end of the same, fitted with coned outlets or jet holes a², (see
Figure 2) coming in advance of and directed into the path of an air blast issuing
from the outlet 62, of the taper nozzle b', of the air blast passage b, fitted at its
tail end 6, with an elastic tube c; leading to an air engine, motor or forcing
expedient. The glaze delivery pipe a, is fitted with a regulating or stop cock d,
whilst the nozzle has a screw plug e, which is capable of being taken out for the
purpose of removing any accumulated solid matters from the inner sides of
the jet holes, whilst the tail end f, has a flexible pipe leading from a delivery
chamber under air pressure, or from an elevated vat or any other source.
I prefer to deliver the said liquid glaze under regulated pressure.
I prefer to use in conjunction with my glaze blast the accessories as represented
in Figure 4. That is, the liquid glaze delivery pipe is, by a bent and depending
end in communication with an air chamber g, into which liquid glaze is
forced through a supply pipe h, in communication with a pump i, consisting of a
piston and piston rod, ³, a jointed lever, supported at its inner end from an
oscillating link, and with the lower end of the barrel of the pump fitted with a
check valve i, at the top of an inlet 7, depending into a tank of liquid glaze j.
The entrance to the supply pipe 4, has a check valve h', so that by the pump, the
liquid glaze in the tank j, is first lifted from the tank and then forced through the
supply pipe h, into the air vessel g, which equalizes the. pressure and gives a
continuous flow to the glaze by the pressure of the pent-up air exerting itself
upon the liquid, but should the pressure exerted be in excess of the volume
capable of being forced through the delivery pipe, then in such an event the
same is got rid of by a relief valve k, which returns the redundant liquid again to
the tank.
The glaze delivery pipe is connected to the blast pipe through a coupling m.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
First. The employment or use of a glaze or enamel blast for glazing or
enamelling earthenware and other goods, that is to say, both converting liquid
glaze or enamel into spray and applying the same by or through the medium of
an air blast or blasts, substantially as described and set forth.
Secondly. A glaze or enamel blast apparatus for both converting liquid glaze or
enamel into spray and applying the same to an article to be coated, consisting of a
liquid glaze delivery passage or passages with an air blast passage or passages,
with the outlets or jet holes of the former coming in advance of and designed to

page_text: deliver the liquid in the path of the outlet or outlets of the blast nozzle or
nozzles substantially as and for the purpose described and set forth.
Thirdly. The general construction, arrangement and combination of the parts of
the glaze or enamel blast apparatus substantially as and for the purpose described
and set forth in Figures 1, 2 and 3.
Fourthly. The combination with the glaze or enamel blast apparatus as
represented in Figures 1, 2 and 3, of the apparatus represented in Figure 4, sub-
stantially as and for the purpose described and set forth.
Dated this 27th day of December 1893.
THOMAS WILLIAM TWYFORD,
By Henry Skerrett,
6, Livery Street, Birmingham, Agent for Applicant.