Improvements in or relating to Pneumatic Tyres.
Year: 1893

page_text: Date of Application, 27th June, 1893-Accepted, 12th Aug., 1893
COMPLETE SPECIFICATION.
Improvements in or relating to Pneumatic Tyres.
A communication from PIERRE MERCIER, of Paris, in the Republic of France,
Chemist.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, 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 present invention relates to a pneumatic tyre for cycle and other wheels.
This tyre is constructed so as to render it proof against deflation after being
accidentally punctured, the puncture immediately and automatically being stopped
so that none of the compressed air can escape.
In the accompanying drawings
Figure 1 is a transverse section of the improved tyre.
Figure 2 is an enlarged view of a part of the tyre showing, by way of illustration,
a hole in the tyre closed up automatically.
In carrying this invention into practice there is produced on the interior surface
of the tyre a sort of distribution or compression of molecules. For that purpose
there is used an outer tube B of preferably vulcanized indiarubber as usual
preferably lined at the interior with canvas S to which are successively applied two
more substances, viz. ;-
1. A layer M which is applied to the tyre during its manufacture and which
consists in an elastic material with a tendency to enlarge its volume through the
absorption of a certain liquid as hereafter more fully explained.
2. A suitable liquid to be absorbed by the said layer M for the purpose of
expanding the latter; it being applied only after the tyre has been vulcanized.
In order to facilitate the distribution of the said liquid evenly all over the
layer M and to equalize the air pressure in the interior in case of puncturing, there
is provided a second canvas lining T which is rigid enough to cause any disturbance
in a portion of the periphery to be borne by the neighbouring parts.
In the accompanying drawings B represents an india rubber tube which may be
vulcanized in the ordinary way and provided with a canvas lining S and can be
applied directly to the wheel.
The canvas lining S at the interior of the tube B is covered with a layer M
consisting preferably of indiarubber only slightly vulcanized so that it may absorb
easily any suitable fatty or oily substance. In this stage the tyre is not yet proof
against the escape of the air through puncturing and in order to render it proof I
introduce a sufficient quantity of liquefied vaseline, the latter may be used hot
so as to facilitate absorption.
The vaseline becomes gradually absorbed by the layer M and tends to enlarge
the volume of the latter resulting in a compression of the molecules.
It is therefore clear that the said layer M in being thus compressed, will close
any hole in the tyre such as shown in PO O' Figure 2 through the tendency of the
molecules in the layer M to push in all directions as indicated by the arrows E and
to close immediately and automatically such holes and thereby prevent the escape
of the compressed air from the tyre.
Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondent, and in what manner
the same is to be performed, I declare that what I claim is
;-
A pneumatic tyre for cycle and other wheels proof against deflating after
puncture consisting of a canvas lined and vulcanized indiarubber tube such as S B

page_text: to the interior of which are applied first an absorbing substance capable of
enlarging its volume through absorption (preferably indiarubber only slightly
vulcanized) and secondly a material such as vaseline or other fatty or greasy
equivalent capable of being absorbed by the before mentioned layer so as to
produce a compression of molecules in the said layer thereby enabling the latter to
close up automatically and immediately any puncture in the tyre substantially as
described and illustrated in the accompanying drawings.
Dated this 27th day of June 1893.
W. P. THOMPSON & BOULT,
Of London, Nottingham, Liverpool, and Manchester,
Agents for the Applicant.