IMPROVEMENTS IN THE MANUFACTURE OF INDIA-RUBBER COMPOUNDS
Year: 1878

page_text: LETTERS PATENT to William Henry Bates, George Bidlake, and Hugh
Faulkner, all of Leicester, in the County of Leicester, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF INDIA-RUBBER COMPOUNDS."
Sealed the 11th February 1879, and dated the 26th September 1878.
PROVISIONAL SPECIFICATION left by the said William Henry Bates, George
Bidlake, and Hugh Faulkner at the Office of the Commissioners of Patents on
the 26th September 1878.
WILLIAM HENRY BATES, GEORGE BIDLAKE, and HUGH FAULKNER, all of
Leicester, in the County of Leicester. "IMPROVEMENTS IN THE MANUFACTURE OF
INDIA-RUBBER COMPOUNDS."
The object of the present Invention is to prepare and combine together india-
rubber compounds possessing different degrees of clasticity and certain peculiar
characteristics which will render the compound article particularly adapted for
various useful purposes. A rubber compound well known in the arts under the
name of "junction rubber" is composed of two kinds of rubber compound joined
together, one kind being a highly elastic vulcanized rubber, and the other a hard
rubber possessing but a very slight degree of elasticity and but little strength or
tenacity. These two compounds are usually placed one on the other and are firmly
united together during the vulcanizing process. The effect produced is that one
side of the block or sheet is soft and highly elastic in one direction, while the other
side is hard and but very slightly elastic. The hard compound is, moreover, liable
to crack, and being deficient in tenacity, is incapable of resisting tensile strain.
This junction rubber has been found useful for some purposes when it has not been
subjected to tensile strain, but there are many other purposes for which it would
be quite inapplicable and in part totally useless, whereas our improved rubber com-
pound will be found admirably adapted to resist any amount of tensile strain which
the softer and more tenacious compound is capable of resisting. In order to effect

page_text: this object we combine with the rubber sulphur and other ingredients (usually)
employed in manufacturing vulcanized rubber) fibrous materials such as comminuted
rags, papier maché, paper pulp, or disintegrated vegetable fibre. These fibres
(which should by preference be previously prepared) must be intimately mixed
with the rubber by means of a masticating or other suitable apparatus, and the
mass may then be subjected to the vulcanizing process, when a flexible, very tena-
cious, and but slightly elastic compound will be produced. The soft and highly
elastic rubber compound is made in the usual way, and in order to connect the two
kinds together it will only be necessary to bring them into close contact and press
them together before vulcanizing, and then subject the double compound to the
vulcanizing process, when the two compounds will be found so firmly united
that they cannot be pulled asunder without subjecting them to a strain greatly in
excess of that to which they are intended to be exposed when in use.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Henry Bates, George Bidlake, and Hugh Faulkner in the
Great Seal Patent Office on the 26th March 1879.
WILLIAM HENRY BATES, GEORGE BIDLAKE, and HUGH FAULKNER, all of
Leicester, in the County of Leicester. "IMPROVEMENTS IN THE MANUFACTURE OF
INDIA-RUBBER COMPOUNDS."
The object of the present Invention is to prepare and combine together india-
rubber compounds possessing different degrees of elasticity and certain peculiar
characteristics which will render the compound article particularly adapted for
various useful purposes in the arts, especially where tensile strain is required to be
resisted. A rubber compound well known in the arts under the name of "junction
rubber" is composed of two kinds of rubber compounds joined together, one kind
being a highly elastic vulcanized rubber, and the other a hard rubber possessing the
character of horn and having but a slight degree of elasticity.
These two compounds are usually placed one upon the other and are firmly united
together during the vulcanizing process. The effect produced is that one side of
the block or sheet is soft and elastic as a cushion, while the other side is hard and
non-elastic. The hard compound is, moreover, liable to crack, and being deficient
in tenacity is incapable of resisting tensile strain. This junction rubber has been
found useful for some purposes, but there are other purposes (as for example where
tensile strain has to be resisted) for which it would be quite inapplicable.
In carrying out our Invention we combine with the rubber sulphur and
other ingredients (usually employed in manufacturing vulcanised rubber), fibrous
materials, such as comminuted rags, papier maché, paper pulp, or disintegrated
vegetable fibre in the proportion say for example of fifty parts by weight of the
disintegrated fibres to fifty parts by weight of the india-rubber compound. The
proportion of fibrous material will vary according to the nature of the goods
intended to be produced, the toughening of the material being increased by an
increase in the proportion of fibrous material. The disintegrated fibre must be
intimately mixed with the rubber by means of a masticating or other suitable
apparatus, and the compound thus produced, when it has been submitted in due
course to the vulcanizing process, will form a flexible, very tenacious, and but
slightly elastic substance, possessing many of the characteristics of leather; we
therefore propose to call it "leather rubber." The part of the compound which is
intended to be elastic is made in the usual way, and in order to connect the two
kinds together so as to form one piece it will only be necessary to bring them into
close contact and press them together preparatory to vulcanizing, and then subject
the double compound to the vulcanizing process, when the two compounds will be
found so firmly united that they cannot be pulled asunder without subjecting them
to a strain greatly in excess of that to which they are intended to be exposed when
in use.
The accompanying Drawing will serve to illustrate the mode of applying our Inven-
tion to two classes of articles. Figures 1, 2, and 4 are transverse sections of bicycle
or other wheel tyres. The parts marked a, a, a in these Figures represent the
slightly elastic part of the double compound, and the parts marked b, b, b, are the
more elastic parts of the double compound, these parts being firmly united as above
explained, the elasticity of the part 6 will be controlled by the tougher and less
elastic portion a of the double compound. Figs. 4 represent plan and edge views of
a flat elastic strap made according to our Invention. In this instance the slightly
elastic ends a, a, of the strap or band have no power to assist the highly elastic
part b (of which the central and by far the largest part of the strap is composed)
in resisting any undue tension to which the strap may be subjected. The parts a
and b are connected by means of a straight bevil joint, as shewn in the Figure. The
parts a permit of their attachment to any rigid substance, and they will resist a

page_text: considerable amount of tension without the liability to tear away from the
fastenings as would be the case if the strap were held by the highly elastic part b.
Figs. 5 represent plan, edge view, and end view of another strap made on the same
principle, but in this case both the faces of the strap are corrugated and the parts a
and bare connected together by means of a lap joint made with a shoulder, as
shewn best in the edge view. It will be understood that in these examples the
elasticity of the hard parts a, a, may be modified by the quantity of non-elastic
fibre which is masticated into the rubber compound.
. Having now described our Invention of "Improvements in the Manufacture of
India-rubber Compounds," and having explained the manner of carrying the same
into effect, we would here remark that we do not claim as our Invention combining
in one piece a hard non-elastic rubber compound with a soft and highly elastic
rubber compound so as to produce what is known as junction rubber, but that
which we consider to be new in our improvements above described and therefore
desire to claim as the Invention secured to us by Letters Patent as aforesaid is,-
Manufacturing double rubber compounds consisting of a flexible, very tenacious,
and but slightly elastic compound in combination with a softer and highly elastic
compound, as and for the purpose herein set forth.
In witness whereof, we, the said William Henry Bates, George Bidlake, and
Hugh Faulkner, have hereunto set our hands and seals, this Twenty-fourth
day of March, in the year, of our Lord One thousand eight hundred and
seventy
W. H. BATES.
G. BIDLAKE.
H. FAULKNER. (L.S.)
(L.S.)
(L.S.)
W. H. BATES.
(L.S.)
G. BIDLAKE.
(L.S.)
H. FAULKNER. (L.S.)