Improvements in Pneumatic Tyres for Velocipedes and other Vehicles.
Year: 1892

page_text: Date of Application, 8th Dec., 1892
Comolete Specification Left, 5th Sept., 1893-Accepted, 7th Oct., 1893
PROVISIONAL SPECIFICATION.
Improvements in Pneumatic Tyres for Velocipedes and other
Vehicles.
1, GEORGE VICTOR GUSTAV LAPSOLU of 63 Rue St. Denis, Paris, Jeweller,
do hereby declare the nature of this invention to be as follows:--
Numerous attempts have been made to prevent deflation of the air chamber of
pneumatic tyres of velocipedes, which frequently occurs when the cyclist passes
over cutting or perforating objects on the road.
Different methods have been tried with this object, generally with small success,
such as the use of a protector which prevents the chamber from being pierced
surrounding the air chamber with plastic material, which should on account of the
pressure close any holes formed; the use of clack valves which rise without being.
pierced when a nail perforates the wall of the chamber and upon the removal of
the nail again press against this wall in such a manner as to stop up the hole which
has been formed.
According to my invention, I form the air chamber of a band of flexible and
extensible material helically coiled to form a tube, by sticking one of its edges upon
the portion already coiled.
According to this method of construction, provided that the size of the band is
suitable relatively to the pitch of the helix, the wall of the chamber may be formed
at all points of a same number of layers of superposed material, and all these
layers except the outermost are when a nail or other sharp or pointed body acts
upon them displaced by sliding and by being pressed in or indented, moreover
the different superposed layers are constantly brought back into place by their
elasticity.
On account of this property that the bands or helices forming my air chamber
have in being displaced when a nail is passed over by the velocipede, the super-
posed layers may be all pierced but each layer will only be pierced after having
first been displaced relatively to the layer pierced before it; therefore the different
layers will be pierced respectively at places which no longer coincide when the
nail is withdrawn and the bands have returned to their normal position. The nail
has not therefore made a continuous hole in the wall capable of opening communi-
cation between the interior and exterior of the chamber, and therefore an escape of
air will not take place.
The efficiency of the apparatus will be greater as the coiled bands forming the.
chamber are constructed in a more flexible and elastic manner, I therefore
preferably employ the purest and best quality of rubber.
In order to facilitate the sliding action I also sometimes place inside the chamber
a lubricating liquid, such as soap and water, glycerine, pure or mixed with water &c.,
which has the advantage of being incongealable.
Dated this 8th day of December 1892.
CARPMAEL & CO.,
Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Pneumatic Tyres for Velocipedes and other
Vehicles.
I, GEORGE VICTOR GUSTAV LAPSOLU, of 63 Rue St. Denis, Paris, Jeweller,
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:-
Numerous attempts have been made to prevent deflation of the air chamber of
pneumatic tyres of velocipedes, which frequently occurs when the cyclist passes
over cutting or perforating objects on the road.
Different methods have been tried with this object, generally with small success,
such as the use of a protector which prevents the chamber from being pierced,
surrounding the air chamber with plastic material, which should on account of the
pressure close any holes formed; the use of clack valves which rise without being
pierced when a nail perforates the wall of the chamber and upon the removal of
the nail again press against this wall in such a manner as to stop up the hole which
has been formed.
According to my invention, I form the air chamber of a band of flexible and
extensible material helically coiled to forin a tube, by sticking one of its edges upon
the portion already coiled.
According to this method of construction provided that the size of the band is
suitable relatively to the pitch of the helix, the wall of the chamber may be formed
at all points of the same number of layers of superposed material, and all these
layers except the outermost are when a uail or other sharp or pointed body acts
upon them displaced by sliding and by being pressed in or indented, moreover the
different superposed layers are constantly brought back into place by their
elasticity.
On account of this property that the bands or helices forming my air chamber
have in being displaced when a nail is passed over by the velocipede, the super-
posed layers may be all pierced but each layer will only be pierced after having
first being displaced relatively to the layer pierced before it, therefore the different
layers will be pierced respectively at places which no longer coincide when the
nail is withdrawn and the bands have returned to their normal position. The nail
has not therefore made a continuous hole in the wall capable of opening communi-
cation between the interior and exterior of the chamber and therefore an escape of
air will not take place.
The efficiency of the apparatus will be greater as the coiled bands forming the
.chamber are constructed in a more flexible and elastic manner, I therefore
preferably employ the purest and best quality of rubber.
In order to facilitate the sliding action I a so sometimes place inside the chamber
a lubricating liquid, such as soap and water, glycerine, pure or mixed with water &c.,
which has the advantage of being incongealable.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a partial elevation to an enlarged scale of an air chamber constructed
according to my invention in which the helical winding has not been completed.
One end of the figure is in section showing the thickness of the superimposed layers
of rubber which in this example are four in number.
Figure 2 is an end view looking from the right of Figure 1.
The method of constructing the air chamber will with the assistance of these
drawings be readily understood. It simply consists in taking a band a of thin and
very elastic indiarubber, this band being of any convenient size, and winding it
helically on itself, care being taken to adjust the pitch of the helix to the size of

page_text: the band, or reciprocally, so as to obtain the desired number of superimposed
thicknesses, which number can be more or less varied. Either before or after the
winding of the band the interior surface of it is covered with cement for a greater
or less width, for example for the width 65 and the edge so covered adheres to the
tube upon which it is wound and which is formed of the previously wound spirals.
By reason of this joint the air chamber becomes tight and there is no risk of the
internal air escaping by passing between the superimposed thicknesses.
In order to be more sure of avoiding all leakage I sometimes enclose the helically
wound chamber in a tube of indiarubber or other material cemented inside or t
cement around this chamber a tape wound in a spiral of very long pitch.
The whole part of each of the spirals forming the air chamber which is not
attached either to an internal or external layer is entirely free and these super-
imposed free extremities serve as I have explained to stop the holes produced by
nails or other pointed or sharp bodies.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
An air chamber for the tyres of velocipedes and other vehicles constructed of a
band of flexible and elastic material wound in a helix so as to form a tube of which
the wall is composed at all points of several thicknesses of material such band
having one of its edges attached to the part previously wound, the said air chamber
being covered or not with an envelope attached to its outside.
Dated this 5th day of September 1893.
CARPMAEL & Co.,
Agents for the Applicant.