Improvements in Pneumatic Tyres and in Means for Securing the same to the Rims of Wheels.
Year: 1891

page_text: Date of Application, 9th Dec., 1891
Complete Specification Left, 7th Sept., 1892-Accepted, 29th Oct., 1892
PROVISIONAL SPECIFICATION.
Improvements in Pneumatic Tyres and in Means for Securing the
same to the Rims of Wheels.
I, ARTHUR DECOURDEMANCHE, of the firm of A. Decourdemanche et Cie., of
Choisy le Roi, in the Republic of France, Manufacturers, do hereby declare the
nature of this invention to be as follows:-
This invention relates to improvements in what are known as pneumatic tyres for
bicycle and other wheels, and in the method of fixing such tyres to the wheels.
The improved tyre consists of a hollow air chamber of sufficiently soft india
rubber, which may be combined with canvas or other woven material in the usual
way.
This circular india rubber air chamber has formed upon its inner circumference,
during the process of manufacture, a rib of much harder india rubber extending
completely round the tyre either continuously or with intervening spaces, and
having the form in transverse section of a more or less acute wedge.
The air chamber is also provided with an opening and valve through which air
can be forced into it in the usual way by a pump.
The air chamber is contained in an exterior casing of soft india rubber, of
greater thickness at the outer than at the inner part of its circumference, and
combined with one or more thicknesses of suitable canvas or cloth to enable it to
resist the pressure of the air in the inner chamber.
These thicknesses of canvas or cloth may be arranged as preferred, either in the
substance of the india rubber or upon the surface of the latter, and they are
preferably doubled at the edges of the casing to give greater strength.
In cross section this exterior casing does not form a complete tube but its two
parallel edges which are made of hard india rubber are enlarged and made of such
shape that their inner edges fit closely against the sides of the wedgeshaped rib on
the inner tube or chamber whilst their outer edges fit into continuous angular
recesses round the inside of the iron or steel tyre of the wheel.
In order to fit the tyre described upon the wheel, the air is allowed to escape
from the inner chamber which is then fitted into the wheel tyre the wedge shape
rib being inwards.
The outer covering is then fitted upon the inner tube, one of its thickened edges
being fitted against the wedge shaped rib and into the corresponding recess in the
wheel tyre, and the opposite edge is then fitted into the other recess by degrees,
the air chamber and rib being raised with the fingers and the edge of the covering
Air is then
introduced gradually until it has been entirely inserted into its recess.
forced into the inner chamber which is dilated by the pressure and pressed every-
where into contact with the casing, the wedge shaped rib especially being forced
between the two enlarged edges of the covering, which it separates and forces into
the recesses in the wheel tyre, the whole being thereby firmly and immoveably
fixed so long as the pressure of air continues. On withdrawing the pressure, the
several parts can be quickly and easily taken apart, and any necessary repairs can
be effected with great facility.
By the improved method of construction and arrangement described, the
pneumatic tyre is very firmly fixed upon the wheel, and there is very great
elasticity since only a small part of the surface of the elastic tyre is embraced by

page_text: the wheel tyre, whilst very great facility is afforded for repairing the pneumatic
tyre and keeping it in good condition.
Dated this 9th day of December 1891.
EDWARDS & Co.,
35, Southampton Buildings, Chancery Lane, London,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Pneumatic Tyres and in Means for Securing the
same to the Rims of Wheels.
I, ARTHUR DECOURDEMANCHE, of the firm of A. Decourdemanche et Cie., of
Choisy le Roi, in the Republic of France, Manufacturers, 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 and
accompanying drawing that is to say :-
This invention relates to improvements in what are known as pneumatic tyres
for bicycles and other wheels, and in the method of fixing such tyres to the
wheels.
The improved tyre consists of a hollow annular air chamber or tube, of sufficiently
soft india rubber, which may be combined with canvas or other woven material in
the usual way.
This circular india rubber air chamber has formed upon its inner circumference,
during the process of manufacture, a rib of much harder india rubber extending
completely round the tyre either continuously or with intervening spaces, and
having the form in transverse section of a more or less acute wedge.
The air chamber is also provided with an opening and valve through which air
can be forced into it in the usual way by a pump.
The air chamber is contained in an exterior casing of soft india rubber, of
greater thickness at the outer than at the inner part of its circumference, and
combined with one or more thicknesses of suitable canvas or cloth to enable it to
resist the pressure of air in the inner chamber.
These thicknesses of canvas or cloth may be arranged as preferred, either in
the substance of the india rubber or upon the surface of the latter, and they are
preferably doubled at the edges of the casing to give greater strength.
In cross section this exterior casing does not form a complete tube, but its two
parallel edges which are made of hard india rubber are enlarged and made of such
shape that their inner edges or sides fit closely against the sides of the wedge
shaped rib on the inner tube or chamber, whilst their outer edges fit into con-
tinuous angular recesses round the inside of the iron or steel tyre of the wheel
In order that my invention may be clearly understood I have shewn, in the
accompanying drawing a pneumatic tyre made according to the above description.
In this drawing, the tyre is represented in cross section and the letters of
reference designate the following parts:
a is the air chamber, provided with the wedge-shaped rib 6 as above described.
c is the exterior casing or envelope, the enlarged edges or sides g, g', of which
fit closely against the wedge shaped rib 6 of the air chamber and on plane
surfaces d, d, provided in the wheel tyre e..
The dotted line shews a method in which the canvas or cloth imbedded in the
outer casing c may be arranged.
In order to fit the tyre described upon the wheel the air is allowed to escape
from the inner chamber a which is then fitted into the wheel tyre e, the wedge
shaped rib b being inwards.
The outer covering c is then fitted upon the inner tube a, one of its thickened
edges g being fitted against the wedge shaped' rib and into the corresponding

page_text: recess d in the wheel tyre, and the opposite edge g¹ is then fitted into the other
recess by degrees, the air chamber and rib being raised with the fingers and the
edge of the covering introduced gradually until it has been entirely inserted into
its recess. Air is then forced into the inner chamber a which is dilated by the
pressure and forced everywhere into contact with the casing, the wedge shaped
rib b especially being forced between the two enlarged edges g, g', of the covering,
which it separates and forces into the recesses in the wheel tyre, the whole being
thereby firmly and immoveably fixed so long as the pressure of the air continues.
On withdrawing the pressure, the several parts can be quickly and easily taken
apart, and any necessary repairs can be effected with great facility.
By the improved method of construction and arrangement described, the
pneumatic tyre is very firmly fixed upon the wheel, and there is very great
elasticity since only a small part of the surface of the elastic tyre is embraced by
the wheel tyre, whilst very great facility is afforded for repairing the pneumatic
tyre and keeping it in good condition.
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. In a pneumatic tyre the combination with an inner air chamber provided
with a wedge shaped rib or projection, of an outer casing or envelope with
enlarged edges, so that when the inner chamber is inflated, the edges of the casing
may be firmly secured between the above mentioned rib and the wheel tyre,
substantially as set forth.
2. In a pneumatic tyre, the inner air chamber a provided with the rib b and the
envelope or casing c, in combination with the wheel tyre e provided with
recesses d, d', into which the enlarged edges g, g', of the casing are fitted and
firmly secured, substantially as and for the purpose set forth.
Dated this 6th day of September 1892.
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicant.