AN IMPROVED PROCESS IN THE VULCANIZATION OF INDIA-RUBBER AND OTHER SIMILAR SUBSTANCES UNDER PRESSURE
Year: 1860

page_text: LETTERS PATENT to John Talbot Pitman, of the American and European
Patent Offices, No. 67, Gracechurch Street, London, for the Invention
of "AN IMPROVED PROCESS IN THE VULCANIZATION OF INDIA-RUBBER AND OTHER
SIMILAR SUBSTANCES UNDER PRESSURE."-A communication from Messrs.
Bourn, Brown, & Chaffee, residing abroad, in the City of Providence, in
the State of Rhode Island, one of the United States of America.
Sealed the 25th January 1861, and dated the 3rd August 1860.
PROVISIONAL SPECIFICATION left by the said Jolin Talbot Pitman at'
the Office of the Commissioners of Patents, with his Petition, on the
3rd August 1860.
I, JOHN TALBOT PITMAN, of the American and European Patent Offices,
No. 67, Gracechurch Street, Loudon, do hereby declare the nature of the.
said Invention for "AN IMPROVED PROCESS IN THE VULCANIZATION OF INDIA-RUBBER
AND OTHER SIMILAR SUBSTANCES UNDER PRESSURE," a communication to me from
Messrs. Bourn, Brown, & Chaffee, residing abroad, in the City of Providence,
in the State of Rhode Island, one of the United States of America, to be.
as follows:-
It is more particularly applicable to the manufacture of mats for doors,.
floors, or other purposes, having raised surfaces in the form of ridges,
cones, &c.; it consists in first forming the metallic die by planing or otherwise

page_text: removing from the flat piece of metal the spaces necessary to receive the
raised portions of the mat when moulding, and a hoop may be secured around
its edge to form the outer ridge or border. The face of the die having been
lubricated with soap and water or other material, the flat sheet of material
to be impressed is placed upon it. The surface of the sheet next the die
should consist to a certain depth, say 3d part of an inch, of good material, the
remainder may be composed of poorer material. A cotton or other cloth is
laid over the back of the sheet, and the whole is then placed in a press having
its bed plate & follower heated by steam, and there subjected to the heat and
a strong pressure. When under a pressure of 80 pounds of steam to the:
inch, the material is vulcanized in seven or eight minutes, and in that
proportion; it is then withdrawn, and while hot is removed by pulling it off
by means of the cloth from the mould. Without the assistance of the cloth or
other similar agent it would be nearly if not quite impossible to draw the
material from the mould without.destroying or injuring it by tearing, especially
when a poor quality is used in its composition.
SPECIFICATION. in pursuance of the conditions of the Letters Patent, filed
by the said John Talbot Pitman in the 'Great Seal Patent Office on
the 2nd February 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
TALBOT PITMAN, of the American and European Patent Offices, No. 67, Grace-
church Street, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of August, in the year of our Lord
One thousand eight hundred and sixty, in the
year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Talbot Pitman, Her special licence that I, the said John
Talbot Pitman, or my executors, administrators, and assigns, or such others.
as. I, 'the said John Talbot Pitman, 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 "AN IMPROVED 'PROCESS IN THE VULCANIZATION OF INDIA-RUBBER
AND OTHER SIMILAR SUBSTANCES UNDER PRESSURE," a communication to me from

page_text: Messrs. Bourn, Brown, & Chaffee, residing abroad, in the: City of Providence,
in the State of Rhode Island, one of the United States of America, upon the
condition (amongst others) that I, the said John Talbot Pitman, my exc-
cutors 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 John Talbot Pitman, do hereby
declare the nature of my said 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 is more particularly applicable to the manufacture of mats
used for doors, floors, or other purposes having raised surfaces in the forms of
ridges, cones, &c., and composed of india-rubber; it consists in first forming a
metallic die or mould by planing or removing in a similar manner from the
flat surface of the metal the spaces necessary to receive & form the raised
portions of the mat when moulding. A hoop may be secured around its edge
to form the outer ridge or border of the mould. The face of the mould is
then moistened with soap and water or other suitable lubricating material, and
the flat face or sheet of the material to be impressed is placed upon it. The
surface of the sheet next the die to a certain depth, say 3d part of an inch,
should consist of good material, the remainder may be composed of poorer.
One of the great advantages obtained by using this Invention is in making
such a combination. A cotton or other fabric of sufficient strength is then
laid on the back of the sheet, and the whole is placed in a press heated in any
convenient manner, usually by steam let into the hollow bed plate and follower,
and there subjected to a suitable heat and pressure. When it is subjected to
a steam heat marked by the guage as 80 pounds pressure to the square inch,
the vulcanization is effected in seven or eight minutes, and in like proportion,
as will easily be ascertained by practice. Withdrawn from the press the mat
while hot is removed from the mould by pulling it off by means of the cloth.
Without the strength given to the mat by the cloth or other similar agent, it
would be nearly if not quite impossible to draw it from the mould without
tearing, and the danger is increased in proportion to the quantity of poor
material used.
Having now described the Invention as communicated to me, and the
manner in which it is operated, what I claim and desire to secure under the

page_text: herein-before in part recited Letters Patent, is the use of the mould press,
the lubricating and strengthening materials in combination for forming &
vulcanizing mats or other similar articles under pressure, substantially as:
described.
In witness whereof, I, the said John Talbot Pitman, have hereunto set
my hand and seal, on this Third day of December, anno Domini One
thousand eight hundred and sixty.
JOHN TALBOT PITMAN. (L.S.)