Improvements in Means for Closing Punctures in the Walls of Pneumatic and Hydraulico Chambers.
Year: 1898

page_text: Date of Application, 30th Dec, 1898-Accepted, 4th Mar., 1899
Improvements in Means for Closing Punctures in the Walls of
Pneumatic and Hydraulico Chambers.
I, GASTON MARTEAU D'AUTRY, of Le Brou d'Autry, par Vierzon (Cher), France,
Engineer, 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..
Various natural and manufactured products and materials capable of serving as
inner coatings for pneumatic tyres have been tried with a view to protect these
tyres against punctures These coatings, which are of a semi-fluid, plastic, or
glutinous nature, are intended to stop up automatically any punctures that may
occur in the an-tube, and thus to shut off perfectly and constantly all communi-
cation between the interion of the said tube and the atmosphere Natural and
manufactured products possessing the desired properties are very dear or are
difficult of application, and have given only unsatisfactory results
Now according to this invention I use, in the place of those products, natural
or manufactured caoutchouc, which, by heating it to a temperature about from
10° to 20° C above its normal fusing point, I bring into the condition of a sticky
and viscous mass The caoutchouc, after being treated in this manner, will
remain in the condition mentioned for many years irrespectively of the tempera-
tune to which may be cooled down Although it is sufficiently viscous to pie-
vent it from running, such caoutchouc has nevertheless the fluidity necessary to
enable it to stop up instantly any punctures that may be made in the cover to
which it is applied The temperature to which the caoutchouc must be raised,
varies slightly according to whether one employs the natural caoutchour or the
waste of vulcanized manufactured caoutchouc The essential point is to exceed
the fusing point, which varies between 180° and 200° C If the caoutchouc is
left at rest, its pasty consistency appears to disappear after some time, especially
if the layer of caoutchouc is thin and exposed to the air, but in reality its solidi-
fication is only apparent In fact if it be kneaded slightly, it will instantly
resume its peculiar condition of viscosity Now, a layer of caoutchouc treated in
this manner when placed inside an air-tube (or any pneumatic cushion that
receives a continual movement), will be constantly kneaded and maintained in a
state of semi-fluidity sufficient for the purpose for which it is intended
The layer of caoutchouc may be applied in various ways to the inside of the
cover or the an-tube to be protected After the coating has been applied, it
may be covered with a thin sheet of caoutchouc or any suitable fabric, such as
Linen or canvas that will limit its width and will prevent it from adhering at
points where it would be injurious or inconvenient.
In order to diminish still further to a certain extent the fluidity of the coating,
there may be embedded in it one or more layers of a fabric having very loose
meshes, such as tulle Strips of felt suitably impregnated with the paste may be
nrenared so that they can be applied ready made

page_text: The coating may be completely enveloped in a skin of caoutchouc and placed
in position in an air-tube during the manufacture of the latter that is to say
before its vulcanization Such a coating may be applied to all hollow articles
composed of caoutchouc and subjected to an internal pneumatic or hydraulic pres-
Bure.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is,-
As a protection for pneumatic tyres, air-tubes, and analogous hollow articles of
caoutchouc, a coating of caoutchouc that has been heated to a temperature exceed-
ing its normal fusing point, whether the said caoutchouc be used by itself or in
combination with strips of fabric or other materials embedded therein or impreg-
nated therewith.
.
.
1000
F. WISE HOWARTH,
46, Lincoln's Inn Fields, London, W.C, Chartered Patent Agent