IMPROVE- MENTS IN THE MANUFACTURE OF HARD INDIA-RUBBER
Year: 1857

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,'
in the County of Middlesex, and of 166, Buchanan Street, in the City
of Glasgow, North Britain, Gentleman, for the Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF HARD INDIA-RUBBER."-A communication
from Madame Anna Chadbourne Morey, of Paris, in the Empire of
France Widow of Charles Morey of the same Place. Esquire, deceased.
PROVISIONAL SPECIFICATION left by the said John Heury Johnson
at the Office of the Commissioners of Patents, with his Petition, on the
4th April 1857.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of 166, Buchanan Street, Glasgow, North Britain, Gentleman,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF HARD INDIA-RUBBER," a communication from Madame Anna
Chadbourne Morey, of Paris, in the Empire of France, Widow of Charles
Morey, of the same Place, Esquire, deceased, to be as follows:-
This Invention relates to an improved mode of preparing hard india-rubber,
whereby it is rendered more homogenous and sound, and is free from all
imperfections arising from the existence of small holes or cavities therein,
at present so injurious to the strength of the articles manufactured of this
material. A saving of time and fuel is also effected in the vulcanizing process,
and an economy of india-rubber obtained by the admixture therewith of
certain cheap foreign substances, which greatly improve the texture and nature
of the material.

page_text: Another portion of the Invention relates to an improved and economical
mode of making the moulds for india-rubber articles.
In order to improve the nature of the hard india-rubber, it is proposed to
mix with the india-rubber, after it has been cut and dried and well broken
under rollers, about half its weight of finely-powdered sulphur and a similar
amount of finely-powdered coal, or of mahogany or rosewood sawdust, either
alone or in combination. Thus, to one hundred pounds of india-rubber is
added about fifty pounds of powdered sulphur. and fifty pounds of powdered
coal or sawdust. The whole is then well mixed together by means of rollers,
and formed into sheets, if required in that form, and placed on tin or glass
plates to be vulcanized.
The vulcanizing process is begun with about 3ths atmospheres, which
degree of heat is maintained for about an hour, when it is gradually increased
to 4ths atmospheres, the whole process occupying about five hours and
twenty minutes, being about 2 hours less than the usual time.
In order to prevent moulded articles from losing their form when under the
vulcanizing process, it is proposed to place them in boxes with alternate layers
of articles and pipeclay or very fine sand, until the box is full; the cover is
then put on, and a bag cloth placed over it to prevent the condensed steam
falling again on the box or case. The whole is placed in the vulcanizator, and
when the articles are withdrawn they will be found unchanged in shape, and
requiring only a little hand labor to render them fit for market.
In place of the expensive carved or cast metal moulds at present employed
in the moulding of articles in india-rubber, it is proposed to make the moulds
themselves in two halves of hard india-rubber from plaster casts of the articles
to be moulded. A number of these moulds are fitted in a frame worked by a
powerful press, the material to be moulded being cut into a suitable form
before being placed in the moulds.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on
the 1st October 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
and of 166, Buchanan Street, in the City of Glasgow, North Britain, Gentle-
man, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of April, in the year of our Lord One
thousand eight hundred and fifty-seven, in the twentieth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said John
Henry Johnson, Her special license that I, the said John Henry Johnson, my
executors, administrators, and assigns, or such others as I, the said John Henry
Johnson, my executors, administrators, or 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 HARD INDIA-RUBBER," a communication from Madame Anna
Chadbourne Morey, of Paris, in the Empire of France, Widow of Charles
Morey, of the same Place, Esquire, deceased, upon the condition (amongst
others) that I, the said John Henry Johnson, by an instrument in writing
under my hand and seal, 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 Henry Johnson; 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, that is to say :-
It is well known to manufacturers of hard vulcanized india-rubber that it
is difficult by the ordinary processes to make an article free from holes,
cavities, and defects of this kind are injurious both to the strength and appear-
ance of such articles.
Now, the first part of this Invention relates to an improved mode of pre-
paring hard india-rubber, whereby it is rendered more homogenous, sound,
and free from imperfections arising from the presence of small holes or cavities
therein.
By my mode of preparation a saving of time and fuel is also effected in the
vulcanizing process, and an economy of india-rubber is obtained by the ad-
mixture therewith of certain cheap substances, which improve the texture and
nature of the material.
In order to improve the quality of the hard india-rubber, I propose to mix
with the raw india-rubber, after it has been cut and dried and well broken
under rollers, about half its weight of finely-powdered sulphur and a similar

page_text: quantity of finely-powdered coal, or of fine wood sawdust, preferring the saw-
dust to be of mahogany or rosewood, alone or in combination. Thus, to
one hundred pounds of india-rubber are added about fifty pounds powdered
sulphur and fifty pounds of powdered coal or sawdust. The whole is then
well mixed together by means of rollers, and formed into sheets, if required in
that form, and placed on tin or glass plates to be vulcanized.
The vulcanizing process is begun with steam of about 3ths atmospheres,
and this is continued for about one hour, when steam of about 4ths atmo-
spheres is gradually employed, the whole process occupying about five hours
and twenty minutes, being about two hours less than the usual time.
In order to prevent moulded articles from losing their form when under the
vulcanizing process, it is proposed to place them in boxes, with alternate layers
of articles and pipeclay or very fine sand, until the box is full; the cover is
then put on, and sackcloth placed over it to prevent the condensed steam
falling again on the box or case. The whole is then placed in the vulcanizing
receptacle, and when the articles are withdrawn they will be found unchanged
in shape, and requiring only a little hand labor to make them fit for the
market.
With regard to the second part of my Invention, I propose to use moulds of
hard india-rubber in place of the expensive carved or cast metal moulds at
present employed in the moulding of articles of india-rubber. I propose to
make such hard india-rubber moulds from plaster casts of the articles to be
moulded in the usual way, but in two halves, for the greater convenience of
moulding. A number of these moulds can be fitted into a frame worked by
a powerful press, the material to be moulded being cut into a suitable form
before being placed in the moulds.
By these means the cost of the process of moulding is greatly reduced, since
the india-rubber moulds are inexpensive, and many articles can be moulded at
the same time, thus effecting a saving of time and labor.
In witness whereof, I, the said John Henry Johnson, have hereunto
set my hand and seal, the Twenty-ninth day of September, One
thousand eight hundred and fifty-seven.
J. HENRY JOHNSON. (L.S.)