IMPROVEMENTS IN MACHINERY FOR CUTTING INDIA RUBBER, IN RENDERING FABRICS WATERPROOF, AND IN MAKING ARTICLES THEREFROM, AND IN DISSOLVING INDIA RUBBER AND OTHER GUMS
Year: 1847

page_text: FORSTER, of Streatham, in the County of Surrey, Manufacturer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Second day of Septem-
ber. One thousand eight hundred and forty-seven. in the eleventh year of
Her reign, did. for Herself. Her heirs and successors, give and grant unto
me, the said Thomas Forster, my exors, admors, and assigns, Her especial
licence, full power. sole privilege and authority, that I, the said Thomas
Forster, my exors, admors, and assigns, or such others as I, the said Thomas
Forster, my exors, admors, or assigns, should at any time agree with, and no
others. from time to time and at all times during the term of years therein
expressed, should and lawfully might make, use, exercise, and vend. within
England. Wales, and the Town of Berwick-upon-Tweed. my Invention of
"IMPROVEMENTS IN MACHINERY FOR CUTTING INDIA RUBBER, IN RENDERING FABRICS
WATERPROOF, AND IN MAKING ARTICLES THEREFROM, AND IN DISSOLVING INDIA
RUBBER AND OTHER GUMS," in which said Letters Patent is contained a
proviso that I. the said Thomas Forster, shall cause a particular description
of the nature of my said Invention, and in what manner the same is to
be performed, by an instrument in writing under my hand and seal, to be
inrolled in Iler 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 in and by the same, reference being thereunto had, will more fully
and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Forster, do hereby declare that the nature of my said Invention,
and in what manner the same is to be performed, are fully described and
ascertained in and by the following statement thereof, reference being had to
the Drawings hereunto annexed, and to the figures and letters marked thereon,
that is to say :-
My improvements in machinery for cutting india rubber or compounds of
india rubber, consists firstly, in the use of metal cylinders covered with india
rubber or gutta percha alone or in combination with india rubber. A Patent
was granted to me in conjunction with W-
Allsop, November Twenty-
fifth, One thousand eight hundred and forty-four, for cutting shect india rubber
upon a cylinder, such cylinder being of wood. I find in practice that large
cylinders of wood are very liable to become untrue from the continual run of
water from them requisite to keep the knife wet, I therefore cover metal
cylinders with a coating of india rubber or gutta percha, or those two matters
combined; such coating 1 prefer to be about half an inch thick, but other
thicknesses may be used. To cover the cylinder, I take a sheet of india
rubber or gutta percha, or combinations thereof, such sheet being about the
twentieth of an inch thick; I proceed to roll the sheet carefully and tightly
round the cylinder, first slightly moistening the sheet with any of the solvents
of rubber; but if gutta percha alone is used, it should be done in a temperature
of not less than one hundred and twenty degrees, but the manipulations of
these matters are well understood. It will be obvious that this coating of india
rubber will prevent the water touching the metal cylinder, and will also keep
the edge of the knife in good condition. I employ cylinders of metal coated as
above, and I prefer such cylinders to be of cast iron as being the cheapest, and
the diameter from fifteen to eighteen inches, the length three feet; but I do
not confine myself to the dimensions, but I find these dimensions convenient
in practice; in other respects the directions given in my said former Specifi-
cation are to be observed when cutting sheet india rubber.
Another part of my improvement is in the means of regulating the various
sizes of the threads or strands of india rubber: it is usual in cutting tapes
from bottle india rubber to place the bottle upon a roller of wood (about three
inches diameter), to which is attached a long screw of the same length, so that
when the roller is made to revolve, the screw working in its female screw
makes the roller travel to the knife, thus cutting the india rubber spirally,
making as many cuts to the inch as there are number of threads to the inch
on the screw (thus the name of india rubber thread 20, 30, 40, now the usual
designation by most manufacturers), requiring a separate screw for every size

page_text: of thread required; these screws being long are very expensive from the
accuracy of the workmanship, and their being very liable to injury unless great.
care is used.
This part of my Invention it will be seen consists of regulating the sizes
of the threads of india rubber when cutting upon large cylinders by the use of
only one screw, which is caused to move at different speed by changing certain
of the drums according to the size of thread required. But that this part of
my Invention may be better understood I will proceed to describe the Draw-
ings, in which Figure 1 shows a side view, Figure 2 a plan, Figure 3 a section,
and Figure 4 an end view of a machine with parts arranged according to the
Invention. a is the cylinder having on its surface a coating of india rubber on
which is placed the cylinder of india rubber to be cut into a thread by means
of the revolving knife b, and this knife bis affixed to the axis c on which
is aflixed the pulley d which receives motion by means of a strap from the
drum e on the axis f, which receives motion from a steam engine or other,
suitable power by means of a strap or band acting on the drum or pulley g.
The axis c is supported at each end by the arms from the axis i to which is
affixed the handle for the purpose of bringing up the knife to the india
rubber to be cut, and the handle j is capable of being so held by means of the
rest which is aflixed by means of a piu joint, as shewn, to the handle j, and
when the rest is slipped forward the knife will fall back and the handle will
rest on the stop k. The cylinder a is supported by its necks in the frame 1,
which is capable of sliding to and fro on guides when controlled to do so by
means of the screw m which turns freely in the framing, and passes through a
On
female screw formed on a projection from the under side of the frame 1.
the outer end of the screw is affixed a drum n over which passes a strap or
band o, which also passes over the pulley p from which it receives motion, and
this pulley p is affixed on the axis q which is driven by a band passing round
the drum or pulley r affixed thereon. The axis q is formed square within its
bearing in the main framing, so that (while it is capable of sliding freely length-
wise through the necks or axis of the cylinder a as the cylinder a is moved to and
fro by the screw m) in its revolution it causes the cylinder a to revolve.
And
it will be seen that by varying either of the drums or pulleys n or r the speed
of the screw in. relation to that of the cylinder will be varied, varying the
thickness of the thread cut off.
My improvements in rendering fabrics waterproof, consists firstly, in saturat-
ing the fibres of the fabrics that have been or are to be coated with india
rubber or other flexible gums. It is well known that india-rubber solution
does not saturate the fibres or capilliary properties of cloths or fabrics or leather,

page_text: therefore a Macintosh coat upon exposure to rain becomes saturated with water
upon the outside. My improvement is to prevent the absorption of water.
The means of effecting this object are numerous, videlicet, saturating the
fibres with stearine, wax, spermaceti, linseed, or other oils, oil varnishes, acid
soaps, gum or shellac, asphalte, resin, tar, &c. with or without solvents of the
various repellant articles used, I will therefore only describe those that I have
found to be most serviceable. I take of stearine or spermaceti twenty pounds;
of beeswax five pounds, and melt them in a metal vessel in a water or sand
bath, and then add fifty pounds of oil of coal or turpentine or other cheap
solvent of these matters, preferring oil of coal. When they are combined,
I apply the liquid while warm with a brush or any other suitable means,
taking care to apply no more than sufficient to saturate the fabric that the
solvent may not have time to act upon the gums with which the cloth is united
or coated; this should be done in a room at about ninety degrees; the solvent
will quickly dry and leave the fabric sufficiently charged with the fatty matter
to repel water. It will be obvious that any fatty matter or gum, resin, tar, or
bituminous matters may be applied in the same manner, and will answer the
purpose more or less well. I also prepare paper and other fabrics, as above,
which is good and useful for wrapping goods and other uses. If smell is an
objection, the spermaceti may be dissolved by carbonate of ammonia, as that
is done by hatters, and then applied to the paper and dried in a room at one
hundred degrees. To effect the desired object with acid soaps, I take ten
pounds of yellow or other soap, preferring yellow, and water twenty gallons,
and boil them gently until the soap is dissolved, and saturate the fabric by
immersion or other suitable means, and when the fabric is nearly dry I
immerse it in a solution of sulphuric acid and water in the proportions of five
pounds of acid to twenty gallons of water; and if the article is likely to be
exposed to a warm or damp temperature or to be used for a short time and
then laid by, as tilts for cart and rick covers, I use in the first bath one pound
of white arsenious acid, one and half pounds of potass or soda to every ten
pounds of soap, boiling it with the soap until the arsenic is dissolved; then
fabrics that are not prepared with acid soaps, I preserve by first saturating
them with a solution of arsenate of potass or soda in the proportion of one
pound of the arsenate to one gallon of water, and when dry proceed with the
other matters; I take thoroughly boiled linseed oil rendered drying by any of
the well-known methods, which is well understood by japanners, enamellers
of leather, and others, to this oil I add any suitable color, and then proceed to
spread it thinly, evenly, and quickly with a spatula, or other suitable means,
care being taken that a thin layer is first put on and allowed to dry

page_text: before enough is put on to bring up a bright surface, it is essential should be
strongly drying and thick from boiling; I then put the cloth into a stove at
about one hundred and seventy degrees to dry. This process being such as is
usually adopted by japanners of leather, it will be readily perceived that any
other drying oils or oil varnish will answer the purpose more or less well, but I
prefer to describe only those that are to be preferred.
Another part of my improvements in waterproofing consists in the application
of colored compositions of india rubber on it and other flexible gums to cloth
or fabrics for clothing. I find that twenty pounds of india rubber, and four
pounds of shellac combined, as described by me in the Specification of the
Patent granted to me on March the Sixth, One thousand eight hundred and
forty-four, is the best composition for composing the color with; the color I
prefer to use is the hydrate of sulphur (milk of sulphur) as the basis, using it
in the proportion of six pounds to every fifteen pounds of rubber, the quantity
of solvent added being in proportion to the consistence required. I find it best
to perfectly combine the india rubber composition to half the solvent, then to
add the hydrate of sulphur (first rubbing it through a fine sieve) to the other
half, and then mix the whole in the machine or masticating instrument, as
described in the Specification just alluded to. The said machine to be used
cold. I find also that a good coloring basis is formed by mixing one half
hydrate of sulphur and one half of fine Cornish clay in powder, or one half
hydrate and one half oxide of tin, commonly called putty powder, both by
weight; to them may be added other colors such as vermillion and a little
vegetable black to make a dove grey, or a little chrome to make a buff or
yellow. If dark colors are required I prefer using the combinations of rubber
and asphalte, as described in the before-named Patent, and add to the chrome
for the various shades of green or vermillion for the shades of brown, or any
suitable color to produce the tints required. As the light colors are likely to
soil, I cover them while wet with finely powdered French chalk, and when
dry well rub off the superfluous. If necessary I first color the chalk to near
the shade required by the addition of a little color to it, taking care to
intimately mix by grinding them together with a little water, and then
thoroughly drying it and reducing it to powder by rubbing through a sieve.
1 also finish paper or other fabrics rendered waterproof by coating with india
rubber or gutta percha, or compositions of them, on one or both sides; then I
take Cornish white for the base, and color it if necessary by the addition of.
any color to produce the desired shade (which is well understood by paper
stainers); to these I add a little good parchment size or a thin solution of

page_text: caoutchouc or any other proper vehicle for binding the colors, taking care
that the adhesive matter shall not be more than sufficient to hold the color
firm; then proceed to coat the fabric thinly with a brush, and when dry such
fabrics will be free from adhesiveness and much more sightly. In making
articles from fabrics made waterproof by any of the means herein described,
I have them sewn with thread prepared with stearine or spermaceti and wax,
as herein described.
The improvements in dissolving india rubber and other gums consist in
using combined solvents that will act upon the rubber and also upon the
shellac, gum copal, or other combinations with rubber, the article so combined
not being soluble in the usual solvents for rubber: for example, a Patent was
granted to me, as before alluded to, bearing date March the Sixth, One thou-
sand eight hundred and forty-four, for the combination of india rubber and
other gums. If, therefore, I desire to use the mixture therein named, videlicet,
india rubber, shellac, copal, and asphalte, say three pounds of india rubber to
one pound of lac, asphalte, and copal mixed and combined, as therein stated,
first removing them from the hot masticating pan and putting it into a cold
one, I add spirits of wine 60 over proof saturated with oil of coal at 30 over
proof. This combination of solvents will speedily combine with the india
rubber and other matters, and when used will be found to work better and
be more free from smell than any of the present solvents. When I require an
article quite free from unpleasant smell I use india rubber three pounds, and
shellac one pound, and combine them as before, and then add about three
quarters of a pound of spirits of wine or it combined with fragrant essential oils,
or musk, or tonquin beans, or orris root; the spirit must be added to the rubber
a little at a time, the shellac will soon absorb it, and the mass will become plastic,
and may be readily spread with rollers a little warmed. A larger quantity of
lac, say two pounds to three pounds of india rubber, and one and a quarter
pound of spirit of wine makes an excellent cement for uniting fabrics; I also
use the combined solvents for the purpose of dissolving gum courie, or New
Zealand gum, an article in abundance, but not hitherto in use from its difficult
solubility; it will also dissolve gums of the copal kind, shellac. &c.; they only
require simply to be pounded and added to the spirit cold, and it dissolves
them most readily. Spirits of wine at 60 over proof, and oil of coal at thirty
over proof, will combine well in equal proportions by measure; of course less
strengths will combine in other proportions, and it is essential that they should
be combined to saturation; but should the mixture be milky the point of
saturation has been passed, and more spirits of wine must be added until the

page_text: spirit is bright or clear. And I find that such spirit alone greatly facilitates the
combining of india rubber with shellac, and allows of such compound being
readily spread.
Having thus described the nature of my said Invention, and in what manner
the same is to be performed, I do not confine myself to the exact details so
long as the peculiar character of my Invention be retained. But what I
claim is,-
Firstly, for coating metal cylinders with india rubber or gutta percha or com-
binations thereof, for cutting india rubber or its compounds. And I also claim
the means used to regulate the sizes of the thread, cut as herein described, in
place of having a different screw for each size.
Secondly, claim the rendering repellent of water all fabrics coated or
united with rubber, or gutta percha, or other flexible gums or combinations
of them, effecting that object by the use of stearine, spermaceti, wax, linseed
or other oils, acid soaps, gum or shellac, asphalte, tar, or resin,
Thirdly, I claim for the manufacture of colored fabrics, the said colored
fabrics being made by the addition of the desired color to india rubber, gutta
percha, or combinations of them, such colored compositions being applied to the
outside of the fabric, and the manufactured garments, as coats, hats, caps, boots,
and other articles to have the colored composition outside. I would remark
that I do not claim the making of black composition with india rubber, that
having been done before.
Fourthly, I claim the use of hydrate of sulphur (milk of sulphur) Cornish
white, and oxides of tin as coloring matters.
Fifthly, I claim for rendering repellent paper and other fabrics with stearine,
spermaceti, or wax. And I also claim for finishing paper and fabrics which
have been coated on one or both sides with india rubber, gutta percha, or
their combinations by covering them with paints.
Sixthly, claim the use of alcohol and coal oil combined as solvents for
gums, gum resin, or other bituminous matters, and also their combinations
with india rubber or gutta percha. And 1 also claim the use of alcohol when
combining india rubber with shellac.
I do not confine myself to any of the proportions here given, but I believe
them to be the best.
In witness whereof, I, the said Thomas Forster, have hereunto set my
hand and seal, this Second day of March, in the year of our Lord
One thousand eight hundred and forty-eight.
THOMAS (L.S.) FORSTER.

page_text: AND BE IT REMEMBERED, that on the Second day of March, in the
year of our, Lord 1848, the aforesaid Thomas Forster came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose. .
Enrolled the Second day of March, in the year of our Lord One thousand