IMPROVE- MENTS IN MOULDING CRUCIBLES AND OTHER HOLLOW ARTICLES OF PLASTIC MATERIALS AND IN APPARATUS EMPLOYED THEREIN
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 "IMPROVE-
MENTS IN MOULDING CRUCIBLES AND OTHER HOLLOW ARTICLES OF PLASTIC
MATERIALS AND IN APPARATUS EMPLOYED THEREIN."-A communication
from abroad, by Samuel Maynard, of New York, United States of
America.
Sealed the 23rd March 1866, and dated the 26th September 1865.
PROVISIONAL SPECIFICATION left by the said Richard Archibald
Brooman at the Office of the Commissioners of Patents, with his Petition,
on the 26th September 1865..
I, RICHARD ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of
London, Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN MOULDING CRUCIBLES AND OTHER HOLLOW ARTICLES OF
PLASTIC MATERIALS AND IN APPARATUS EMPLOYED THEREIN," to be as follows:-
In the manufacture of crucibles and other vessels of plastic material a
"former" of some kind has long been employed to give shape to the interior
while the vessel was being turned on the "jigger" or upright lathe. In the
case of crucibles it is particularly desirable that all of a lot should be of
uniform size and thickness. The size externally is controlled by the mould
in which it is made, while the accuracy of the interior is due to the

page_text: means by which the forming tool is governed in its action. Many devices
have been made for moving this up gradually, so as to spread the plastic
material upon the interior of the mould, and finally holding it firmly at the
position which will give the required thickness, but all of these have been
found defective in some repect. By the present Invention the action of the
forming tool is governed with unerring exactness.
The Invention consists in mounting the former upon a fixed centre so
placed with reference to the curve of the forming edge that when the said
former is lifted out of the finished crucible, the first act of moving it shall also
withdraw it from contact with the crucible.
In operation the lever c is
In the annexed Drawings a represents the forming tool shown as within
a finished crucible 6; it is firmly affixed to a lever c, which is bent down
at the end opposite to the edge of a, and secured by a bolt at d upon the
bed in which the spindle works, and upon which bolt it can be turned freely.
This fixed centre must be so placed in its relation to the forming tool that when
the tool enters the mass of plastic material, as in the position shown in red
lines, it will on being turned further on the centre d approach the side of the
mould until arrested by a stop as at e which governs the thickness of the
crucible. The moulds employed are usually of plaster of Paris, and divided
longitudinally into two parts in order that the crucible may be more readily
taken out when sufficiently dry. These moulds are set in a hollow chuck
f, and are confined together at the top by a hoop.
turned over upon the centre d until the former a is entirely out of the way; the
sections of the mould are then put upon the chuck and secured by the hoops and
bars k; the proper weight of plastic material is then put into the mould. To
facilitate the work this may be spread somewhat with the hand, and the former
being then brought down upon it the material will be evenly spread upon the
interior of the mould as that is revolved. The pressure upon the handle of c
is to be continued until it strikes its stop, thus giving density and finish to the
crucible. By now turning the lever c back upon d the former will be moved
away from the surface of the crucible, and continuing the motion will be with-
drawn from the crucible. The screws n are then released, the mould taken
from the chuck and set away for the crucible to dry in it, as is usual in pottery
work when plaster moulds are used. I do not claim the method of securing
the sections of the mould to each other and to the chuck.

page_text: 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 26th March 1866.
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 Twenty-sixth day of September, in the year of our
Lord One thousand eight hundred and sixty-five, in the twenty-ninth 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, 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 MOULDING CRUCIBLES
AND OTHER HOLLOW ARTICLES OF PLASTIC MATERIALS AND IN APPARATUS EM-
PLOYED THEREIN," (communicated to me from abroad by Samuel Maynard,
of New York, United States of America,) 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.
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 Drawing
hereunto annexed, that is to say:-
In the manufacture of crucibles and other vessels of plastic material a
former of some kind has long been employed to give shape to the interior
while the vessel was being turned on the "jigger" or upright lathe. In the
case of crucibles it is particularly desirable that all of a lot should be of
uniform size and thickness. The size externally is controlled by the mould

page_text: in which it is made, while the accuracy of the interior is due to the means by
which the forming tool is governed in its action. Many devices have been
made for moving this up gradually so as to spread the plastic material upon
the interior of the mould, and finally holding it firmly at the position which
will give the required thickness, but all of these have been found defective in
some respect. By the present Invention the action of the forming tool is
governed with unerring exactness.
The Invention consists in mounting the former upon a fixed centre so
placed with reference to the curve of the forming edge that when the said
former is lifted out of the finished crucible the first act of moving it shall also
withdraw it from contact with the crucible.
In the annexed Drawing a represents the forming tool shown as within a
finished crucible b. It is firmly affixed to a lever c, which is bent down at
the end opposite to the edge of a and secured by a bolt at d upon the bed in
which the spindle works, and upon which bolt it can be turned freely. This
fixed centre must be so placed in its relation to the forming tool that when
the tool enters the mass of plastic material, as in the position shewn in red
lines, it will on being turned further on the centre d approach the side of the
mould until arrested by a stop as at e, which governs the thickness of the
crucible. The moulds employed are usually of plaster of Paris, and divided
longitudinally into two parts, in order that the crucible may be more readily
taken out when sufficiently dry. These moulds are set in a hollow chuck f
and are confined together at the top by a hoop. In operation the lever c is
turned over upon the centre d until the former a is entirely out of the way;
the sections of the mould are then put upon the chuck and secured by the
hoops and barsk; the proper weight of plastic material is then put into the
mould. To facilitate the work this may be spread somewhat with the hand
and the former being then brought down upon it the material will be evenly
spread upon the interior of the mould as that is revolved. The pressure on the
handle of c is to be continued until it strikes its stop, thus giving density and
finish to the crucible. By now turning the lever c back upon d the former
will be moved away from the surface of the crucible, and continuing the
motion will be withdrawn from the crucible. The screws n are then released,
the mould taken from the chuck and set away for the crucible to dry in it, as
is usual in pottery work when plaster moulds are used.
And having now described the nature of the said Invention, and in what
imanner the same is to be performed, I declare that I claim the construction
and employment in moulding crucibles and other hollow articles of plastic
materials of apparatus in which the former or forming tool for the interior

page_text: of such articles is mounted, substantially as herein-before described and repre-
sented in the accompanying Drawing.
In witness whereof, I, the said Richard Archibald Brooman, have
hereunto set my hand and seal, this Twenty-third day of March, One
thousand eight hundred and sixty-six.