IMPROVEMENTS IN OR APPERTAINING TO PROVISIONAL SPECIFICATION
Year: 1881

page_text: LETTERS PATENT to John Britton, of Stamford, in the County of Lincoln,
Ironmonger, for an Invention of "IMPROVEMENTS IN OR APPERTAINING TO
PROVISIONAL SPECIFICATION left by the said John Britton at the Office
of the Commissioners of Patents on the 28th January 1881.
JOHN BRITTON, of Stamford, in the County of Lincoln, Ironmonger. "IMPROVE-
MENTS IN OR APPERTAINING TO FIRE GRATES OR CONTAINERS, CHIEFLY FOR
DOMESTIC USE."
One of the chief objects which I have in view is to obtain what is generally
known as "slow combustion" in common stoves and grates without the necessity of
removing the existing stove or grate and replacing it with an expensive apparatus,
such as those which form in themselves the whole grate, fireplace, and often mantel
piece as well.
I form my "stove bottoms" of a variety of shapes to suit the different grates,
etcetera, to which they may be applied; they are portable, and can be promptly
removed from one room to another if the shapes and sizes of the grates permit.
The material I prefer to employ is fire clay or other material possessing similar
properties, and a common shape consists of a flat bottom with back and two sides;
this is lowered into the existing grate and can be removed at pleasure. Sometimes
it is desirable to form the bottom thicker at the back and sloping to the front, and
sometimes (particularly when it is desired to reduce the capacity of the grate) I
make the two sides converge towards the back and meet in an angle. For front
bars, those of the existing grate are utilized when practicable. Sometimes,
particularly with inferior coal, it is advisable to have a few holes to admit a little
air just to assist the combustion where it is too slow.
Where the existing grate is small for the requirements, and it is not desirable to
occupy 'much of the space, I employ 'very thin fire clay and case it, wherever
needed, with metal to strengthen it.
The thickness and proportions of the material must of necessity vary much,
but for ordinary purposes it would not exceed three inches, or even, when cased,
be less than half an inch; I do not however bind myself to these thicknesses.
In some cases a very cheap form can be made by using simply a bottom without
back or sides; this may be thick or thin, and encased, as already described, if
necessary,, pierced with holes or not, and may, if preferred, be laid on top of the
existing grate and bars, as also could the other forms previously described.
It will be seen that these "bottoms" are simple, portable, handy, and cheap, and
eminently suitable for the purpose for which they are designed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Britton in the Great Seal Patent Office on the 27th July
1881.
JOHN BRITTON, of Stamford, in the County of Lincoln, Ironmonger. " IMPROVE-
MENTS IN OR APPERTAINING TO FIREGRATES OR CONTAINERS, CHIEFLY
DOMESTIC USE."
FOR
One of the chief objects which I have in view is to obtain what is generally
known as "slow combustion" in common stoves or grates without the necessity of
removing the existing stove or grate and replacing it with an expensive apparatus,
such as those which form in themselves the whole grate, fireplace, and often mantel
piece as well.
I form my simplex stove bottoms, as I call them, of a variety of shapes to suit
the different grates, etcetera, to which they may be applied; they are portable and
can be promptly removed from one room to another if the shape and sizes of the
grates permit. The material I prefer to employ is fire clay or other material
possessing similar properties, and a common shape consists of a flat bottom with
back and two sides; this is lowered into the existing grate and can be removed at.
pleasure. Sometimes it is desirable to form the bottom thicker at the back and
sloping to the front, and sometimes (particularly where it is desired to reduce the
capacity of the grate) I make the two sides converge towards the back and meet
in an angle. For front bars, those of the existing grate are utilized when
practicable. Sometimes, particularly with inferior ashy coal, it is advisable to
have a few holes to admit a little air just to assist the combustion where it is
too slow.
Where the existing grate is small for the requirements, and it is not desirable
to occupy much of the space, I employ very thin fire clay and case it, wherever
needed, with metal to strengthen it.
The thickness and proportion of the material must of necessity vary much, but
for ordinary purposes it would not exceed three inches, or even, when cased, be
less than half an inch; I do not however bind myself to these thicknesses.
In some cases a very cheap form can be made by using simply a bottom without
back or sides; this may be thick or thin, and encased, as already described, if
necessary pierced with holes or not, and may, if preferred, be laid on the top of the
existing grate bars, as also could the other forms previously described.
A very low back draught requires a very thin "bottom," whilst a very large deep
grated old fashioned stove would be suited with a very thick one. The wedge-
shaped form of bottom, thicker at back than front, is chiefly employed where
there is a mechanical difficulty to be overcome in the grate bottom.
It will be seen that these "bottoms" are simple, portable, handy, and cheap,
and eminently suitable for the purpose for which they are designed.
Reference to the accompanying Drawings will more clearly explain the nature
of this Invention.
Fig. 1 is a plan of a "bottom" composed entirely of fire-clay or equivalent, the
holes shown in the bottom are for admitting air when bad coal is used. The holes
let out the dust without materially affecting the principle; they are applicable to all
the different shapes. Fig. 2 is a front elevation of Fig. 1, the holes in the bottom
being dotted in. Fig. 3 is a plan of a "bottom" with sides converging towards
the back and nearly or quite meeting at the back in an angle. Fig. 4 is a front
view of the same. Fig. 5 is a plan of the "bottom" when cased with metal
chiefly for strength, when the fire clay is too thin on account of want of room, or
for some other reason; however, when desired, I can of course use the metal casing

page_text: with a thick lining. Fig. 6 is a section through the centre of Fig. 5, and it will
be noticed that the holes are formed by little bits of small piping, preferably
screwed into the metal at the bottom; the fire clay is generally placed in the casing
and round the pipes while soft, and fired afterwards.
Fig. 7 shows, in section, a plain flat "bottom" without back or sides; it may be
thin and cased with metal, as shown, or thicker, and made solid without the casing.
Fig. 8 is a section of the wedge-shaped" bottom," thicker at the back than the front,
the relative thicknesses of back and front varying with circumstances.
Fig. 9 is
a plan showing in dotted lines the horizontal or approximately horizontal holes
from the front to the vertical ones at the back; these are also shown in the section,
Fig. 8. The direction, position, and size of the holes can be varied to suit
circumstances, so I do not bind myself to always place them as indicated in the
Drawings.
I have hitherto chiefly alluded to fire clay as the material from which to make
these bottoms, and on account of its being suitable, easily procurable, and reasonably
cheap, I prefer generally to employ fire clay for the purpose, nevertheless it is
evident that there are other materials from which they may be made, such, for
instance, as asbestos, sand, or pumice stone, so mixed or treated as to hold together.
Having now described my Invention and the method of performing the same, I
wish it to be understood that what I claim and desire to protect under the
hereinbefore in part recited Letters Patent is,--
First. The herein described construction of portable slow combustion stove
bottoms, consisting essentially of bottom, back, and sides in one piece of fire-
clay or its equivalent, substantially as and for the purposes set forth and shown.
Second. In a portable slow combustion stove bottom, the employment of the
vertical or other holes, substantially as and for the purposes set forth and shewn.
Third. The hereindescribed construction of portable slow combustion stove
bottoms, consisting of a metal casing lined with fireclay or its equivalent, and,
when necessary, provided with vertical or other holes, substantially as and for the
purposes set forth and shewn.
Fourth. The hereindescribed construction of portable, slow combustion stove
bottom, thicker at back than in front, substantially as set forth and shewn..
In witness whereof, I, the said John Britton, have hereunto set my hand
and seal, this Twenty third day of July, in the year of our Lord One
thousand eight hundred and eighty one.
JOHN BRITTUN. (L.S.)