IMPROVEMENTS IN THE MANUFACTURE OF METAL SASH BARS, COLUMNS, AND MOULDINGS FOR BUILDING AND DECORATIVE PURPOSES, AND FOR A METHOD OF PROTECTING THE SAME OR OTHER ARTICLES FROM OXYDATION
Year: 1856

page_text: LETTERS PATENT to Joseph Bunnett, of Deptford, in the County of Kent,
Engineer, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
METAL SASH BARS, COLUMNS, AND MOULDINGS FOR BUILDING AND DECORATIVE
PURPOSES, AND FOR A METHOD OF PROTECTING THE SAME OR OTHER ARTICLES
FROM OXYDATION."
Sealed the 3rd April 1857, and dated the 7th October 1856.
PROVISIONAL SPECIFICATION left by the said Joseph Bunnett at the
Office of the Commissioners of Patents, with his Petition, on the 7th
October 1856.
I, JOSEPH BUNNETT, of Deptford, in the County of Kent, Engineer, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF METAL SASH BARS, COLUMNS, AND MOULDINGS FOR BUILDING AND
DECORATIVE PURPOSES, AND FOR A METHOD OF PROTECTING THE SAME OR OTHER
ARTICLES FROM OXYDATION," to be as follows:-
These improvements consist, firstly, in the manufacture of sash bars, columns,
and mouldings of sheet iron, by drawing the iron between suitable fixed or
revolving dies; and such sash bars may be formed with the tongue or rebates
complete from a single strip of iron, or from two or more strips combined; or
the sheet-iron sash bar may be drawn with or attached to a solid wrought-iron
tongue, or with a wood or other suitable core.

page_text: Secondly, in covering sheet-iron sash bars, columns, and mouldings (made as
herein-before described) by the ordinary modes of japanning and polishing, or
with glass or vitreous enamels, and producing on the same, and on sash bars,
columns, and mouldings of zinc, brass, or other suitable metals, ornamental
designs in imitation of woods, marbles, buhl, or inlaid work, and other artistic
devices.
Thirdly, in coating sash bars, columns, mouldings, shutters, and other
articles of iron or other oxydisable metal with a protecting surface, by dipping
them in or by brushing them over while in a clean and heated state with a thin
solution of asphaltum in spirits of tar or other suitable solvent, and afterwards
hardening the same by exposure to strong heat, this process being repeated
until a coating of the required thickness is obtained.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Joseph Bunnett in the Great Seal Patent Oflice on the
7th April 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPII
BUNNETT, of Deptford, in the County of Kent, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventh day of October, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Joseph Bunnett, Her special licence that I, the said Joseph Bunnett, my
executors, administrators, and assigns, or such others as I, the said Joseph
Bunnett, my executors, administrators; and assigns,, should at any time agree
with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and, Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF METAL SASH BARS, COLUMNS, AND MOULDINGS FOR BUILDING AND
DECORATIVE PURPOSES, AND FOR A METHOD OF PROTECTING THE SAME. OR OTHER
ARTICLES FROM OXYDATION," upon the condition (amongst others) that I, the said
Joseph Bunnett, my executors or administrators, by an. instrument in writing
under my, or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner. the same

page_text: was to be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said Joseph Bunnett, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
These improvements consist, firstly, in the manufacture of sash bars, columns,
and mouldings of sheet iron, by drawing the iron between suitable fixed or
revolving dies; and such sash bars may be formed with the tongue, or rebates
complete from a single strip of iron, or from two or more strips combined; or
the sheet-iron sash bar may be drawn with or attached to a solid wrought-iron
tongue, or with a wood or other suitable core.
Secondly, in covering sheet-iron sash bars, columns, and mouldings (made as
herein-before described) by the ordinary modes of japanning and polishing, or
with glass and vitreous enamels, and producing on the same and on sash bars
columns and mouldings of zine, brass. or other suitable metals, ornamental
designs in imitation of woods, marbles, buhl, or inlaid work, and other artistic
devices.
Thirdly, in coating sash bars, columns, mouldings, shutters, and other
articles of iron or other oxydisable metal with a protecting surface, by dipping
them in or by brushing them over while in a clean and heated state with a thin
solution of asphaltum in spirits of tar or other suitable solvent, and afterwards
hardening the same by exposure to strong heat, this process being repeated
until a coating of the required thickness is obtained.
And in order that the nature of this my Invention and the manner of
performing the same may be more fully understood, reference is had to the
following description thereof, and to the Drawings hereunto annexed.
For the production of sash bars, columns, or mouldings I take strips of sheet
iron, which I prefer to be about one-twentieth of an inch in thickness, and of
the proper width, according to the size of the finished article; I then draw it
through a series of suitable dies until the desired pattern is obtained, as is well
understood by workmen accustomed to drawing metals. If the best charcoal
iron is employed, and the pattern is not very intricate, it will seldom be
necessary to anneal the iron between the Drawings; but if, from the quality of
the iron or the character of the pattern to be produced, the metal does not
work kindly, I then anneal it to facilitate and perfect the operation.
Figure 1 in the accompanying Drawing is a section of an iron sash bar

page_text: with rebates complete, produced by drawing a single strip of sheet iron
through suitable dies. :
Figure 2 is a section of a sash bar formed of two strips of iron a and b,
which are brought nearly to the required form by drawing them separately
through suitable dies; they are then brought together and drawn through a
finishing die, which unites them together and forms the complete bar.
Figure 3 is a section of a sash bar having an internal core of wood and an
iron tongue. In this case the iron tongue e is first enclosed in the sheet-iron
casing f; the covering piece 9 being drawn of the shape required, the wooden
core h, is placed therein, and the whole drawn through a finishing die,. by
which the ends of the covering piece 9 are brought under, so as to enclose the
ends of the casing f, which unites all the parts strongly together..
Figure 4 is. a section of a sash bar produced by drawing a covering piece of
thin sheet iron cupon a cast or wrought iron strengthening core d of a
cruciform shape, the projecting limb of the cross forming the rebates.
Figure 5 is a section of a sash bar formed of one piece of sheet iron, and an
iron core of a shape, the upper angles of the core fitting into the internal
angles of the sheet iron, and by being drawn through a finishing. die the edges
of the sheet iron are turned in under the T-shaped core and forms the rebate.
Figure 6 is a section of a sash bar or column formed of one piece of sheet
iron, and a wood core of a suitable shape. The sheet iron is first drawn to the
proper size and shape, the wood core is then placed therein, and the whole
drawn through a finishing die, by which the edges of the sheet iron are turned
over and driven firmly into the wood core... In the same manner columns or
mouldings of any desired pattern may be formed of sheet iron, and strengthened
internally with cores of wood or iron, or of both combined, according to the
purposes for which they are intended to be used.
Having in this manner produced sash bars, columns, or mouldings of sheet
iron by drawing them through suitable dies, I finish them for use by coating
them by the ordinary modes of japanning and polishing, or with glass or
vitreous enamels, (but in the latter case wooden cores must not be used,), and
on such sash bars, columns, or mouldings of iron, or of zinc, brass, or other
sheet metal, I produce ornamental designs in imitation, of woods, marbles, buhl,
or inlaid work, and other artistic devices. If the articles are of iron, however,
I prefer to coat them in the first instance with the protecting composition
herein-after described, and then ornament them by graining, coloring, gilding,
or silvering, according to the style of decoration required.
My Invention of a method of protecting sash bars, columns, mouldings,

page_text: shutters, and other articles of iron from oxydation consists in coating them
with a hard and impermeable surface, in the following manner :-The shutter
laths, sash bars; or other articles of iron are first cleansed and freed from
scales, grease, and all other impurities by immersion in a warm acid bath,
composed of about one hundred parts of sulphuric acid and sixteen hundred
parts of water, heated to about 130 degrees of Fahrenheit. The articles are
then rinsed in fair water, immersed in a solution of lime, and dried off quickly
in hot sawdust or in a heated chamber; they are then in readiness for
dipping into the protecting composition, which is made as follows:-About six
hundred parts of asphaltum are boiled in nine hundred parts of linseed oil;.
when the asphaltum is dissolved I add two hundred parts of gum animi
(or gum copal), and to facilitate the admixture of these ingredients I throw in
one hundred parts of red lead and fifty parts of litharge. When these
ingredients are thoroughly incorporated, I add a sufficient quantity of spirits,
obtained by the distillation of Archangel tar, to bring it to a proper state of
fluidity. The articles to be coated having been wiped clean, and heated
to about 250 or 300 degrees of Fahrenheit, are immersed in the composition
prepared as above directed; after standing a short time to drain off the
superfluous fluid the articles are put into a stove or oven, heated to about 180
degrees, and kept there until the protecting surface is thoroughly hardened.
One coating will in most cases be found sufficient; but if a stronger pro-
tection is required, the process of dipping, drying, and hardening may be
repeated. The protecting surface thus given is of a dark color; if other colors
are required a second or third coating may be given, in which any of the
ordinary pigments may be introduced; but if light colors are used, gum copal
must be substituted for the asphaltum. The protecting surface thus given
forms an excellent ground for japanning, gilding, or such other artistic decora-
tion as taste may dictate.
Having now described the nature of my said Invention, and the manner of
performing the same, I desire it to be understood that what I clam is,―
Firstly, the manufacture of sash bars, columns, and mouldings of sheet
iron by drawing strips of that metal through suitable dies, as herein-before
described.
Secondly, the ornamenting of iron sash bars, columns, and mouldings by
japanning and polishing, or by coating them with glass or vitreous enamels,
and producing on the same, and on sash bars, columns, and mouldings of zinc,
brass, or other suitable sheet metal, various artistic designs.
Thirdly, the coating sash bars, shutter laths, columns, mouldings, and other

page_text: articles of iron or other oxydisable metal with a protecting composition, as
herein-before described.
In witness whereof, I, the said Joseph Bunnett, have hereunto set my
hand and seal, this Seventh day of April, in the year of our Lord One
thousand eight hundred and fifty-seven.
Witness,
W. BADDELEY.
JOSEPH BUNNETT. (L.S.)