Improved Mode of Preparing " Variegated Rubber" for Manufacturing Purposes.
Year: 1892

page_text: Date of Application, 9th May, 1892
Complete Specification Left, 22nd Oct., 1892-Accepted, 5th Nov., 1892
PROVISIONAL SPECIFICATION.
Improved Mode of Preparing " Variegated Rubber" for
Manufacturing Purposes.
I, JAMES BURBRIDGE of the firm of Messrs. W. Warne & Company of The
India Rubber Works, Tottenham in the County of Middlesex, India Rubber
Manufacturer, do hereby declare the nature of this invention to be as follows:-
The object of this invention is to produce a rubber compound which, when
vulcanised and cut up for manufacturing purposes, will have a variegated
appearance.
In carrying out my invention, I take layers or sheets of rubber compound of
different colours, preferably red and black, which I pile one on the top of the other
in any order, to the thickness of block or slab required, and then subject to
hydraulic pressure, in order to consolidate the rubber.
From the block or slab thus formed, I cut a strip, say an inch square, and taking
hold of opposite ends, I twist this strip any number of times, so that each layer of
rubber becomes a spiral. I then join the two ends in the usual way, and I place
the ring in an iron mould, and vulcanise it.
When vulcanised, from the ring thus produced I cut bands in a lathe, or in any
other convenient manner, and these bands, instead of being wholly red or wholly
black, or in concentric rings of red and black, will be "variegated," that is to say,
it will have a ground of red, with lines of black crossing it at all kinds of
angles, giving the band a novel appearance, no two bands being exactly alike.
According to this mode of manufacture, the layers of black and red rubber
become intertwisted, and owing to complete consolidation by pressure, the different
rubbers will not separate in use.
When producing the rubber for making other articles, I proceed in a similar
manner, but instead of vulcanising, I gently press the strip of twisted rubber. into
a mould, to give it, say, block form, and from this block I cut thin sheets or strips,
which I make up into the articles required, and then vulcanise in the usual way.
Dated this 9th day of May 1892.
NEWTON & SUN,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improved Mode of Preparing Variegated Rubber for
Manufacturing Purposes.
I JAMES BURBRIDGE of the firm of Messrs. W. Warne & Co. of The India
Rubber Works, Tottenham in the County of Middlesex, India Rubber Manufac-
turers, do hereby declare the nature of this invention and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement :-
The object of this invention is to produce a rubber compound which, when made
up into articles, will have a variegated appearance.
In carrying out my invention, I take layers or sheets of rubber compound of
different colors, say, red and black, which I pile one on top of the other in any
order to the thickness or height I require, and I consolidate this pile of sheets by
placing it under hydraulic or other pressure.
From the block or slab thus formed, I cut off a strip, and holding the two ends
firmly, I twist the strip any number of times, so that each layer of rubber of which

page_text: the strip is composed, will take a spiral form. The amount of twist given to the
strip will determine the character or appearance of the rubber. Thus, if twisted
up.tightly, the rubber will appear subsequently of a knotted pattern, but if not
twisted so much, the design will have the appearance somewhat like wood, with an
open grain.
These twisted strips I then place in a suitable mould, and set them under pressure
and heat in a manner now well understood. When taken out of the mould, the
twisted strips will retain their set form for any length of time.
I then take the strips and cut and join up the two ends in the usual way to form
rings.
A number of these rings I then string on a mandrel, place them in a cylindrical
mould, and subject them to continuous pressure during, say, 12 hours, by which
time perfect union between all the rings will have taken place, and they will form a
solid cylinder.
This cylinder is then withdrawn from the mould, is placed in a cutting machine,
and presented longitudinally to a cutter, so that it may be cut up into sheets of any
desired thickness in the usual way.
The sheets thus produced will have a variegated appearance on both sides, that
is to say, they will have a ground of one color (red), with lines of another color
(black), crossing at all kinds of angles, giving a novel and fanciful appearance to
the surface of the sheets.
These variegated sheets are then cut up and made into various articles, which are
vulcanized in the usual way.
In some cases, as, for instance, in the manufacture of variegated elastic bands,
the cylinder may be subjected to the vulcanising process, after which the bands
may be cut in a lathe, or other convenient manner, from the vulcanised cylinder,
transversely of the same. Or the twisted strips, when joined up and made into
rings, may be vulcanised in that form, and the bands may be cut from the rings in
the lathe, or in any other convenient manner, after vulcanization.
The result of this latter operation will be, that the bands cut will vary in size,
making what is known in the trade as a complete series, and in no case will any two
bands have exactly the same design, and there will be absolutely no waste.
It will be understood that for such goods as elastic bands, pure rubber must be
used in the manufacture, but for many other goods pure rubber is not needed,
especially where a certain degree of hardness is required. My process applies
equally to the production of variegated sheets of other materials capable of
vulcanization.
I would here remark that the above operations are given as examples only. The
manufacture of the sheets or other articles may be carried out in any well known
manner, without departing from the nature of my invention, the essential feature of
which is, the twisting of the strips of consolidated layers of different colored
compounds, prior to their being subsequently treated in any well known manner.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. As a new article of manufacture, variegated rubber for industrial purposes
produced by twisting strips of consolidated layers of different colored compounds,
making up the twisted strips into rings or cylinders, and cutting shavings or sheets
therefrom, either before or after vulcanization, as set forth.
2. The process for making sheets of variegated rubber as herein described, and.
consisting in building up a pile or block of sheets of different colored compounds,
consolidating the saine by pressure, cutting strips therefrom, twisting and setting
said strips, joining the ends to form rings, piling a number of rings one on the other,
and consolidating the same by pressure to form a cylinder, and finally cutting from
the cylinder the sheets to be afterwards made up into various articles, and vulcanized,
as set forth.

page_text: 3. The process for making rubber bands as herein described, and consisting in
building up a pile or block of sheets of different colored compounds, consolidating
the same, twisting and setting strips cut therefrom, and forming the same into rings,
piling a number of rings one on the other, and consolidating the same, by pressure, to
form a cylinder, vulcanizing said cylinder, and finally cutting therefrom the bands, as
set forth.
4. The process for making rubber bands as herein described, and consisting in
building up a pile or block of sheets of different colored compounds, consolidating
the same, twisting and setting strips cut therefrom, joining the ends of the twisted
strips, and vulcanizing, and finally cutting the bands from the rings thus formed, in
a lathe or otherwise, as set forth.
Dated this 22nd day of October 1892.
NEWTON & SON,
Agents for the Applicant.