AN IMPROVED METHOD OF FORMING TAPERED RODS AND BITS
Year: 1865

page_text: LETTERS PATENT to Richard Archibald Brooman, of 166, Fleet Street, in
the City of London, Patent Agent, for the Invention of "AN IMPROVED
METHOD OF FORMING TAPERED RODS AND BITS."-A communication from
of Pasic Frenc
aled the 6th October 1865, and dated the 10th April 1865.
PROVISIONAL SPECIFICATION left by the said Richard Archibald Brooman
at the Office of the Commissioners of Patents, with his Petition, on the
10th April 1865.
J, RICHARD ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of
London, Patent Agent, do hereby declare the nature of the said Invention
for "AN IMPROVED METHOD OF FORMING TAPERED RODS AND BITS," to be as
follows:-
This Invention consists in forming rods and bits tapered by means of the
biting action of a chemical bath instead of by grinding or filing as heretofore.
Thus I form cylindrical rods of circular or polygonal cross section into tapered
or conical rods by causing them to descend and rise at uniform or differential
speed, and to fixed or variable depth in an acid bath, which dissolves the
metal, the vertical motion of the rods may be imparted mechanically or.
manually. The vessel containing the bath is by preference placed under glass.
to allow the progress of the operation being watched. The extent of the taper
or cone depends upon the duration of the immersion, the periodical quickness
of immersion, and the strength and temperature of the bath. For steel rods.
the bath is composed of nitric and. muriatic acids in variable proportious, say,

page_text: for example, 3 parts of nitric and 1 part of muriatic acid; the object of the
muriatic acid is to impart a dead white to the steel. The taper having been
produced after an immersion more or less deep, and of greater speed towards
the end of the operation, I remove the rods from the bath, and plunge them
in a solution of whiting to remove the acid, and preserve the steel rods from
oxidation. The rods to be tapered are suspended from or held in considerable
numbers in plates, and are dipped in the acid bath from the point to the top
to the depth of the taper to be obtained; the duration of the immersion is
about five or six minutes, but the time varies according to the degree of the
taper and the strength of the bath.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Archibald Brooman in the Great Seal Patent Office
on the 10th October 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of London, Patent
Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of April, in the year of our Lord One
thousand eight hundred and sixty-five, in the twenty-eighth year of Her
reign, did, for Herself, Her Heirs and successors, give and grant unto me,
the said Richard Archibald Brooman, Her special licence that I, the said
Richard Archibald Brooman, my executors, administrators, and assigns, or
such others as I, the said Richard Archibald Brooman, my executors, admi-
nistrators, 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 Inven-
tion for "AN IMPROVED METHOD OF FORMING TAPERED RODS AND BITS," (com-
municated to me from abroad by Cesar Auguste Deverte, of Paris, France,)
upon the condition (amongst others), that I, the said Richard Archibald
Brooman, 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 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.

page_text: NOW KNOW YE, that I, the said Richard Archibald Brooman, do hereby
declare the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the Drawings hereunto
annexed, that is to say:-
This Invention consists in forming rods and bits tapered by means of the
biting action of a chemical bath instead of by grinding or filing as heretofore.
Thus I form cylindrical rods of circular or polygonal cross section into tapered
or conical rods by causing them to descend and rise at uniform or differential
speed and to fixed or variable depth in an acid bath which dissolves the metal,
the vertical motion of the rods may be imparted mechanically or manually. The
vessel containing the bath is by preference placed under glass to allow the
progress of the operation being watched. The extent of the taper or conc
depends upon the duration of the immersion, the periodical quickness of
immersion, and the strength and temperature of the bath. For steel rods the
bath is composed of nitric and muriatic acids in variable proportions, say, for
example, three parts of nitric and one part of muriatic acid; the object of the
muriatic acid is to impart a dead white to the steel. The taper having been
produced after an immersion more or less deep, and of greater speed towards
the end of the operation, I remove the rods from the bath, and plunge them
in a solution of whiting to remove the acid, and preserve the steel rods from
oxidation. The rods to be tapered are suspended from or held in considerable
numbers in plates, and are dipped in the acid bath from the point to the top
to the depth of the taper to be obtained; the duration of the immersion is
about five or six minutes, but the time varies according to the degree of the
taper and the strength of the bath.
Having explained the process for forming tapered rods, I proceed to describe
with reference to the accompanying Drawings, the manner of carrying out
the Invention, taking by way of example the manufacture of tapered bits.
I first draw or form rods of polygonal section equal and parallel; but for
clockwork and other purposes where exactitude is required, I prefer rods with
five faces.
Figure 1 represents a rod a with five concave faces, as seen more clearly
on a larger scale in Figure 2. The faces instead of being concave may be
plain as in Figure 3, or the rod may be quadrangular in section as in Figure 4,
or triangular, hexagonal, or circular. I sharpen the end 6 by grinding or filing,
see Figures 5 and 6; I then fasten several of the rods together by wire, and
temper them ; after tempering, I submit them to a solution of caustic potass,
and then wash them with water; I afterwards scour them in a bath of

page_text: muriatic acid diluted with water to remove dirt and foreign matter; I then
wash them again, taking care not to touch them; I next place them in
plates pierced with holes to receive them, and dip all the rods in a biting bath
by a continual downward and upward movement communicated to the plates
in which the rods are held. This dipping in the bath produces the biting of
the rods in a tapered form, on removing them from the bath after having been
submitted to its action for a few minutes, the rods have the tapered form
represented in Figures 7, 8, and 9.
And having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare that I claim, forming rods and
bits tapered by submitting them to the biting action of a chemical bath,
substantially in manner herein-before described.
In witness, whereof, I, the said Richard Archibald Brooman, hath here-
unto set my hand and seal, this Ninth day of October, in the year of
our Lord One thousand eight hundred and sixty-five.
K. A. BROOMAN. L.S.)