IMPROVEMENTS IN THE PREPARATION OF GUTTA PERCHA, AND IN THE APPLICATION THEREOF, ALONE AND IN COMBINATION WITH OTHER MATERIALS, TO VARIOUS MANUFACTURING PURPOSES
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
HANCOCK, of Brompton, in the County of Middlesex, Gentleman, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of the United Kingdom of Great Britain and
Ireland, bearing date at Westminster, the Twenty-fourth day of September,
in the eleventh year of Her reign, did give and grant unto me, the said
Charles Hancock, my exors, admors, and assigns, Her especial licence, full
power, sole privilege and authority, that I, the said Charles Hancock, my
exors, adñors, and assigns, and such others as I, the said Charles Hancock,
my exors, adñiors, or assigns, should at any time agree with, and no others,
from time to time and at all times hereafter during the term of years therein
mentioned, should and lawfully might make, use, exercise, and vend my
Invention of "IMPROVEMENTS IN THE PREPARATION OF GUTTA PERCHA, AND IN THE
APPLICATION THEREOF, ALONE AND IN COMBINATION WITH OTHER MATERIALS, TO
VARIOUS MANUFACTURING PURPOSES," within that part of the United Kingdom
of Great Britain called England, Her said Majesty's Dominion of Wales, and
Town of Berwick upon Tweed, and also in the Islands of Jersey, Guernsey,
Alderney, Sark, and Man, and in all Her said Majesty's Colonies and Planta-
tions abroad; in which said Letters Patent there is contained a proviso that
I, the said Charles Hancock, shall particularly describe and ascertain the

page_text: nature of my said Invention, and in what manner the same is to be per-
formed, by an instrument in writing under my hand and seal, and cause the
same to be enrolled in Her said Majesty's High Court of Chancery within
six calendar months next and immediately after the date of the said in part
recited Letters Patent, as, reference being thereunto had, will more fully and
at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Charles Hancock, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are particularly
described and ascertained in and by this present Specification and instrument
in writing, that is to say :-
My Invention consists, firstly, in certain modes of preparing and treating
gutta percha, alone and in combination with other materials, for manufacturing
purposes, by means of baths, which enable me with advantage to obtain higher
and wider ranges of temperature for that purpose than has been hitherto attain-
able by the use of water only, and also in some cases kneading, manipulating,
and otherwise manufacturing the simple or compound material, and in some
cases also subjecting it to the action of a chemical agent. For temperatures
a little above that of boiling water, I employ a solution, saturated, or nearly. so,
of some...alkaline salt or earth, or any other soluble substance which will
increase the density of the water and elevate its boiling point, such as
carbonate of potash, carbonate of soda, or muriate of lime, or any other
soluble salt which will not. act prejudicially, upon the material, and selecting
more soluble salts or substances in those cases which it. may be desired to
subject the material to higher degrees of temperature. For higher tempe-
ratures I make use of fixed oils, fats, wax, or similar materials, or of any of
the well-known fusible metallic alloys; and for the purposes of such baths, any
other convenient and economical substance may be employed, the melting or
boiling point of which is above the boiling point of water; and in cases. where
a liquid bath is not requisite; and a dry bath sufficient, for the purpose of
preparing the material in the intended manner, a. bath of sand or any similar
substance may be employed. The bath which I use in performing this part
of my Invention (of whichever the aforesaid descriptions it may be) is to be
heated by such of the ordinary means employed for that purpose as may be
most convenient. When the bath yessel is filled with any solution or melted
substance, which will not exert any injurious effect upon the material to be
operated upon, and when the temperature is not raised beyond three hundred
degrees of Fahrenheit, I immerse the gutta percha or compound in the bath,
and keep it so immersed until the mass is thoroughly heated and brought to a

page_text: soft, plastic, or fluid or semi-fluid state, the degree of temperature to which the
material is heated being more or less elevated, according to the purpose to
which it is intended to be applied. When the temperature of the bath
employed is so high, or the substance with which the bath vessel is'filled, is of
such a nature, as to act injuriously upon the gutta percha, alone or compounded
as aforesaid, I enclose it in a case, envelope, or vessel, so as to protect it from
injury, and this case' or envelope may be made of cloth, plaster of Paris, clay,
glass, metal, or of such other substance as may be best adapted for protecting
the material. to be operated upon The vessel used for any of the aforesaid
baths may be open or closed, and the contents may, if necessary, be sub-
jected to pressure during the process of heating, and the vessels may be
made of any shape or size which may be most convenient, according to the
purpose to which it is intended to be applied.
1+
The material or article to be operated upon, whether gutta percha or any of
its compounds, and whether protected by a case or envelope," or not, is to be
kept in the bath in which it is placed for the time which may be requisite for
producing the intended effect. In some cases I select such substances for
baths as will produce a chemical action upon the 'gutta percha or any of its
compounds, 'as caustic alkali or 'a sulphuret of an alkali, or any other suitable
sulphuret, and the temperature to which my baths enable me to raise those
materials will' in many cases cause the chemical agents to act more effectually
or with greater energy. If I wish to deprive gutta percha or any of its com-
pounds of any acid with which it may be mixed, I boil it'in a bath' containing
water, holding caustic potash or soda in solution; and of specific gravity 1010
or 1020; and the temperature of such a bath at its boiling point being higher
than that of water, the acid will be speedily and effectually separated from the
material. The action of the bath upon the material may be increased or
facilitated by agitating, kneading, or otherwise manipulating" it during the
process.
Secondly, my said Invention consists of a method of manufacturing gutta
percha or any of its compounds into vessels and hollow wares, or articles of
various forms, by distending or expanding the material, when in a soft plastic
state, by blowing or forcing air or some other fluid into a bag or piece of
caoutchouc placed within the material of which any vessel or article is intended
to be made, and at the same time (when necessary) subjecting the exterior
parts of the material to the pressure, action, or operation of such moulds or
other instruments as may be necessary to give the intended form, size, or
pattern to the article into which the material is to be manufactured. For the
purpose of making any article in this way, I take a hollow piece of caoutchouc,

page_text: preferring caoutchouc which has been rendered permanently elastic, of the size
and shape which will be sufficient to enable me to distend or expand it in the
requisite manner. This piece of caoutchouc I cover with a quantity of gutta.
percha, or of any of its compounds, sufficient to make the intended article, the
outside of the piece of caoutchouc being first smeared with a little fat, soap, or
some other thing, which will enable me to detach it with facility from the
interior of the article which is intended to be made. The piece of gutta percha,
or of any of its compounds, used in this way, may either be previously made
into a cylinder, sack, or any other shape which may be convenient, and drawn
over or placed upon the outside of the piece of caoutchouc; or the piece of
caoutchouc may be covered with the requisite quantity of gutta percha, or of
any of its compounds, in a plastic or sheet state, in any manner which may be
most convenient.
The piece of caoutchouc being covered with the piece of gutta percha, or of
any of its compounds, in the way already described, the orifice of it is to be
attached by a ligature or any other convenient means to one end of a tube,
through which air or any other fluid may be forced into the interior of the
caoutchouc. The piece of gutta percha, or of any of its compounds, is then to
be heated in a water alkaline bath, or by steam, or by any other convenient
means, until it is brought into a soft plastic state, and then air, water, or some
other fluid convenient for that purpose, is to be blown or forced into the
interior of the piece of caoutchouc, until the caoutchouc and its outside
covering is distended or expanded to the required extent.
In cases when it is intended to make globular articles, and in some other
cases, the blowing or forcing air or some other fluid into the interior of the
materials may be sufficient to produce the required effect and make the article
intended; but it will more frequently be necessary to employ some mould or
other instrument to give the requisite form or pattern to the intended vessel
or article. If I intend to use a mould, I place the material, heated as already
mentioned, within the interior of the mould, and then proceed to distend the
caoutchouc and the piece of gutta percha, or of any of its compounds, by air,
or some other fluid, as aforesaid, until the piece of gutta percha, or of any of
its compounds, is forced into every part of the mould, and by these means is
formed into the shape and impressed with the form and pattern which the
mould is intended to produce.
The article thus made is then to be kept in this distended state until it has
become cool and firm, after which it is to be withdrawn from the mould and
the piece of caoutchouc drawn out of the inside of it. The orifice of the vessel.
or article made in this way may then, if desired; be closed. or trimmed in.

page_text: any manner which may be necessary to finisli the article in the required
manner.
The moulds to be used in performing this part of my Invention may be of
any size, form, or shape which may be convenient, and may be made capable
of impressing the articles to be manufactured within them with any pattern
which may be desired; and these moulds may be constructed in a similar
manner to glass-makers' moulds, or of any other construction or in any other
manner which may be deemed most convenient. In some cases, instead of
using moulds, or in addition to using moulds, other instruments of a similar
description may be used for giving shape or pattern to the exterior of the
article intended to be made..
The piece of caoutchouc which I have described as placed within a piece of
gutta percha, or of any of its compounds, which is intended to be made into
any such vessel or article as aforesaid, I use for the purpose of equalizing the
internal pressure of the air or other fluid, by means of which the piece of
gutta percha, or of any of its compounds, is to be distended into the required
size and shape, or for rendering such pressure equal on every part of the
interior of the article, and for preserving the article from injury by the air or
other fluid being forced through any part of the material to be made into a
vessel or other article, as aforesaid.
In some cases it may be desirable also to protect the outside of a piece of
gutta percha, or of any of its compounds, which is intended to be made into
any vessel or article, as aforesaid, before heating it or placing it in the mould;
and in such cases I protect the material by a covering of caoutchouc, which
will have the effect of keeping the material in its proper position upon the
interior piece of caoutchouc whilst it is being heated in a bath, or by any other
convenient means.
And, thirdly, my said Invention consists of a mode or modes of hardening
gutta percha, in order to render it more durable and better adapted for
bearing friction or resisting the effects produced by exposure to the weather.
For this purpose I- boil gutta percha for an hour or more in a bath containing
a solution of caustic alkali, as before described, and knead the gutta percha
therein at the same time with a wooden agitator or otherwise, and mix with it
a portion of the oxide of iron called colcothar, and of the oxide of lead called
litharge, or of either of those oxides, and I believe that one part of either of
those oxides, or of a combination of them, to seven parts of gutta percha,
or thereabouts, will be a useful proportion in which to mix the materials
together.
The proportions of these materials may, however, he varied. I effect the

page_text: admixture by introducing the intended quantity of both, or of either of these
oxides into a masticating machine, in which I have previously placed the
gutta percha, and then proceed to masticate the contents of the machine-until
the materials are thoroughly incorporated. I.alsó add about ten per cent. of
glue or bituminous matter, preferring it in powder, during the time of
masticating the gutta percha, for the purpose of incréasing its tenacity and
cohesion.
And now having described each of the said parts of my said Invention, I
hereby declare that I claim as ofimy Invention,
Firstly, the mode of preparing or treating gutta percha, alone and in com-
bination with other materials, by means of baths, in manner herein-before
described.
Secondly, the method of manufacturing gutta percha, or any of its com-
pounds, into vessels and hollow wares and articles in manner herein-before
described.
And, thirdly, the combining gutta percha with other materials, in manner and
for the purposes herein-before described.
In witness whereof, I, the said Charles Hancock, have hereunto set my
hand and seal, this Twenty-fourth day of March, One thousand eight
hundred and forty-eight.
Enrolled the Twenty-fourth day of March, in the year of our Lord One
thousand eight hundred and forty-eight.