Improvements in Pneumatic Tyres.
Year: 1893

page_text: Date of Application, 15th Apr., 1893
Complete Specification Left, 13th Jan., 1894-Accepted, 17th Feb., 1894
Improvements in Pneumatic Tyres.
I, LOUIS JEAN MARIE LOISEL, of Tergnier, Aisnes, in the Republic of France,
Doctor of Medicine, do hereby declare the nature of this invention to be as
follows:-
This invention has for its object improvements in the manufacture of the air
chamber or reservoir placed in the interior of pneumatic tyres for wheels of
velocipedes or other vehicles.
These improvements have for their object to render it almost impossible for sharp
objects on the road to injure the air tube, and in the case of the tube being injured
to prevent the escape of air owing to the quick repair of the injury, which repair
is nearly always automatic and which in any case may be easily carried out
by hand.
The air chamber is a tube made of thin flexible material impermeable to air and
preferably also elastic, this tube is much larger than the enclosing envelope which
envelope may be either the outer tyre or preferably an interposed tube of about
the same size as the interior of the outer tyre. The air tube should be able to be
easily displaced in its envelope, and for this object I interpose between the two
either a lubricating liquid, or a powder which facilitates slipping (asbestos powder,
cocoa nut fibre) or a mixture of the twg.
I also lubricate the interior of the central tube in order that its folds or wrinkles
may more easily slide the one on the other.
The inner tube which is very ample and containing abundant material which
forms the air chamber may be simple or multiple that is to say it may consist of
several tubes the one in the other; in this case the different tubes which form this
air chamber and which are all of the same dimensions are independent of each other
(except at the point where the inflating tube is) and I facilitate the movements of
these several tubes by means of a liquid, or a powder or both as above described.
The multiple air chamber instead of being formed as above described of several
concentric tubes, of which the innermost only receives the compressed air, may be
composed of several tubes of smaller diameter placed side by side and all filled
with air; these different tubes are in the same way of ample dimensions and form
lengthwise and cross folds, they are impermeable, very flexible, preferably elastic,
independent the one of the other and their movements are facilitated by the
presence of the lubricating liquid or of a suitable powder as in the preceding case.
It will be understood that the wall either simple or multiple of the air chamber
is by reason of the size which is given to it never distended and consequently if a
nail or other object pierces it, it will not cause it to burst thus forming a large
tear; this in itself is important, but it must be remarked moreover that by reason
of this largeness itself and the liberty of movement that this tube possesses,
generally it will be simply lifted by the nail, before which it will retreat without
offering any resistance and will not be pierced at all. This is what will happen if
it is formed of extremely thin rubber, for then even supposing that the neighbouring
portions of the point attacked do not furnish material sufficiently loose to avoid all
serious pressure of the nail upon the tube, this will on account of its elasticity first
have to be stretched very considerably before it can be perforated; it will thus be
much better that the liquid at the exterior of the tube to which the pressure of the
interior air is transmitted, should fill the cavity produced by the lifting of a point
of this tube by the nail, thus maintaining an equilibrium of pressure on the two
surfaces.

page_text: If nevertheless the tube is perforated, there is a chance, in the case of a multiple
tube that the tube which is behind it or one of those which may follow, will be
lifted by the nail without being pierced, in which case it is clear there will be no
escape of air.
But supposing that all the tubes forming the air chamber are pierced, the opening
will nearly always close itself. For it will be understood that when the tubes have
made such a large movement without being guided at any point because they are
entirely free; when they return to their place, the holes made in the different tubes
will not fall the one on the other; the hole in one of the tubes will thus be stopped
by an intact portion of the next tube, which will be applied with force by the effect
of the interior pressure; and the more the chamber is formed of superposed
thicknesses, the more this automatic repair will be certain.
Besides if there were only a single tube it would be sufficient in principle to
obtain this effect, on condition that this tube is very large, flexible and free in its
movements.
If a hole is formed so large that the automatic return of the tubes the one with
respect to the other is not sufficient to stop it, a relative displacement may be caused
by hand, either by moving the tyre slightly longitudinally whilst the air tube is
kept fixed, or by doing the reverse, or even by displacing both to change the
position of the one and the other with respect to the envelope. You will therefore
be always certain of stopping the hole. Of course, the method of attaching the
tyre and the chamber upon the rim of the wheel should be suitably chosen to allow
these movements to be produced as easily as possible.
It
The multitubular arrangement works on exactly the same principles as the
concentric tube arrangement just described, each of these small impermeable tubes
have the same character of amplitude, flexibility and freedom of movement as the
large tubes and offers the additional advantage of dividing the compressed air in
such a manner that the tyre will lose little of its air in the case where a tear
causes an escape, for in this case it will only affect one tube of the reservoir.
will also easily be understood that in such a case the other tubes will expand more
and fill the space caused by the flattening of the damaged tube. It will moreover
hardly happen that a tube will be completely emptied, for one of the tubes next
the envelope (according to the position it occupies) will beforehand stop the
opening. The use of rubber instead of another material has the same advantage
in both arrangements by reason of the necessity of a nail or other perforating body
stretching this material a great distance without being able to pierce it.
On the other hand of course I use the same precautions as above to assure the
liberty of movement of the tubes.
In the two arrangements the tubes forming the air chamber are preferably
broken that is to say closed at both ends which rejoin each other.
Dated this 15th day of April 1893
CARPMAEL & Co.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Pneumatic Tyres.
I, LOUIS JEAN MARIE LOISEL, of Tergnier, Aisne in the Republic of France,
Doctor of Medicine, 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 :-
This invention has for its object improvements in the manufacture of the air
chamber or reservoir placed in the interior of pneumatic tyres for wheels of
velocipedes or other vehicles.

page_text: These improvements have for their object to render it almost impossible for
sharp objects on the road to injure the air tube, and in the case of the tube being
injured to prevent the escape of air owing to the quick repair of the injury, which
repair is nearly always automatic and which in any case may be easily carried out
by hand.
The air chamber is a tube made of thin, flexible material impermeable to air and
preferably also elastic, this tube is much larger than the enclosing envelope which
envelope may be either the outer tyre or preferably an interposed tube of about
the same size as the interior of the outer tyre. The air tube should be able to be
easily displaced in its envelope, and for this object 1 interpose between the two
either a liquid which lubricates their surfaces and which besides prevents the
formation of a vacuum between the envelope and the tube at places where the
latter separates from it, so that there is always an equilibrium of pressure on
the two faces of the air tube which is therefore displaced without resistance. I
may also replace the liquid by a mixture of a liquid with a powder (powdered
asbestos, cocoa nut fibre or the like).
I also lubricate in the same way the interior of the central tube in order that its
folds or wrinkles may more easily slide the one on the other.
The inner tube which is very ample and containing abundant material which
forms the air chamber may be simple or multiple that is to say it may consist of
a single tube or of several tubes the one in the other; in the latter case the different
tubes which form this air chamber and which are all of the same dimensions are
independent of each other (except at the point where the inflating tube is) and I
facilitate the movements of these several tubes by means of a liquid, or of a
mixture of a liquid with a powder as above described.
The multiple air chamber instead of being formed as above described of several
concentric tubes, of which the innermost only receives the compressed air, may be
composed of several tubes of smaller diameter placed side by side and all filled
with air; these different tubes are in the same way of ample dimensions and form
lengthwise and cross folds, they are impermeable, very flexible, preferably elastic,
independent the one of the other and their movements are facilitated by the
presence of a lubricating liquid or of a mixture of a liquid with a suitable powder
as in the preceding case.
Figure 1 of the annexed drawings shows in perspective a portion of the first type
of air chamber formed of very ample pleated concentric tubes, enclosed in an
envelope which is itself enclosed in the tyre, the drawing shows two of these
corrugated tubes but there may be as said, more or on the contrary only one, on
the other hand the envelope intermediate between the air tube and the tyre may if
preferred be done away with.
Figure 2 shows in a similar view the second type of air chamber with pleated
tubes of small diameter placed side by side.
Figure 3 is a view showing the arrangement fixed to the rim for simultaneously
inflating all the tubes of the multitubular chamber shown in Figure 2, with air at
the same pressure, as well as to prevent these tubes communicating with the
exterior, when once they are inflated.
These drawings clearly show what has been described and what is to be
described. In the arrangement shown in Figure 1 it will be seen that the concentric
tubes a a¹ forming the air reservoir properly so called which are formed of a thin
and very flexible material, which is at the same time impermeable to air, such as
gold beater's skin, silk or other prepared textile fabric, are larger longitudinally
and transversely than the envelope b which encloses them and have in consequence
numerous folds or wrinkles in all directions as has been described. It is also seen
in Figure 1 that these corrugated tubes may be enclosed in an envelope b, this is
not indispensible for the tubes a a' may be placed directly in the tyre c which is
fixed to the rim, but it is preferably used to avoid loss of lubricating liquid or
mixture and to facilitate the relative displacement of the tyre and the air chamber;
it may be made of the same material as this or of different material.
...

page_text: It will be understood that the wall either simple or multiple of the air chamber
is by reason of the size which is given to it never distended and consequently if a
nail or other object pierces it, it will not cause it to burst thus forming a large
tear; this in itself is important, but it must be remarked moreover that by reason
of this largeness itself and the liberty of movement that this tube possesses owing
to the presence of the interposed liquid, generally it will be simply lifted by the
nail, before which it will retreat without offering any resistance and will not be
pierced at all. This is what will happen especially if it is formed of extremely
thin rubber, for then even supposing that the neighbouring portions of the point
attacked do not furnish material sufficiently loose to avoid all serious pressure of
the nail
upon
the tube, this will on account of its elasticity first have to be stretched
very considerably before it can be perforated; it will thus be much better that the
liquid at the exterior of the tube, to which liquid the pressure of the interior air
is transmitted, should fill the cavity produced by the lifting of a point of this
tube by the nail, thus maintaining an equilibrium of pressure on the two
surfaces.
If nevertheless the tube a is perforated, there is a chance, in the case of a multiple
tube that the tube a' which is behind it or one of those which may follow, will be
lifted by the nail without being pierced, in which case it is clear there will be no
escape of air.
But supposing that all the tubes forming the air chamber are pierced, the
opening will nearly always close itself. For it will be understood that when the
tubes have made such a large movement without being guided at any point because
they are entirely free; when they return to their place, the holes made in the
different tubes will not fall the one on the other; the hole in one of the tubes will
thus be stopped by an intact portion of the next tube, which will be applied with
force by the effect of the interior pressure; and the more the chamber is formed of
superposed thicknesses, the more this automatic repair will be certain.
Besides if there were only a single tube a it would be sufficient in principle to
obtain this effect, on condition that this tube is very large, flexible and free in its
movements.
If a hole is formed so large that the automatic return of the tubes the one with
respect to the other is not sufficient to stop it, a relative displacement may be
caused by hand, either by moving the tyre slightly longitudinally whilst the air
tube is kept fixed, or by doing the reverse, or even by displacing both to change
the position of the one and the other with respect to the envelope b. You will
therefore be always certain of stopping the hole. Of course, the method of
attaching the tyre and the chamber upon the rim of the wheel should be suitably
chosen to allow these movements to be produced as easily as possible.
The multitubular arrangement shown in Figure 2 works on exactly the same
principles as the concentric tube arrangement just described, each of these small
impermeable tubes have the same character of amplitude flexibility and freedom of
movement as the large tubes, and the multitubular arrangement offers the additional
advantage of dividing the compressed air in such a manner that the tyre will lose
little of its air in the case where a tear causes an escape, for in this case it will only
affect one tube of the reservoir. It will also easily be understood that in such a
case the other tubes will expand more and fill the space caused by the flattening of
the damaged tube. It will moreover hardly happen that a tube will be completely
emptied, for one of the tubes next to it or the envelope (according to the position
the damaged tube occupies) will beforehand stop the opening. The use of rubber
instead of another material has the same advantage in both arrangements Figure 2
as well as Figure 1 by reason of the necessity of a nail or other perforating body
stretching this material a great distance without being able to pierce it.
On the other hand of course I use the same precautions as above to assure the
liberty of movement of the tubes.
In the two arrangements the tubes forming the air chamber are preferably broken
that is to say closed at both ends which rejoin each other.

page_text: As to the manner of inflating all the tubes of the multitubular air chamber at
the same time, this will be easily understood by the aid of Figure 3.
Each of the tubes a is connected by a small rubber tube d terminated by a metal
union to a distributing box e which is carried by the rim of the wheel; in the neck
of this box a stem is screwed pierced with a longitudinal hole f¹ which has a
right angled bend to open at the side; this stem thus forms a tube to which the
nozzle of the pump is applied to inflate, and which is shut by a cap 9 when the
inflation is complete. The lower end of this same stem f is attached to a disc h,
with a rubber face h', according as the stem f is made to descend or rise by turning
to the right or left in the tapped hole in the box e, the disc h closes the holes
pierced in the bottom of this box or on the contrary it is drawn back and by this
means each of the small air chambers a is isolated or it allows them either to be
simultaneously filled with air or simultaneously emptied of air through an orifice i
provided with a stopper.
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 :-
1. In a pneumatic tyre for velocipedes and other vehicles, an air chamber formed
of one or more tubes much larger in all directions than the envelope which contains
it or them and consequently having both longitudinally and transversely folds or
wrinkles and not being in a state of tension, this tube or each of these tubes being
made of a thin, very flexible and impermeable material, preferably indiarubber,
and which can easily undo its folds and be displaced with respect to the adjoining
walls; the said tubes when there are several being arranged either concentrically
or side by side and in any case every tube having its internal and external surfaces
in contact with a liquid or a mixture of a liquid with a powder in order to insure its
freedom of movement.
2. For the simultaneous inflation and the simultaneous deflation of the several
elements of a multitubular air chamber such as is referred to in the first claim, a
distributing box forming a tube for the entrance of air and as many inflating
orifices as there are tubes in the air chamber and having a moveable plate serving
to close these orifices and also a deflating orifice.
Dated this 10th day of January 1894.