Improvements in Elastic or Pneumatic Tyres for the Wheels of Vehicles.
Year: 1895

page_text: Date of Application, 19th Nov., 1895
Complete Specification Left, 5th May, 1896-Accepted, 27th June, 1896
Improvements in Elastic or Pneumatic Tyres for the Wheels of
Vehicles.
I CHARLES LEWIS HEERMANN DE HUNDERTMARK of 10 Rue d'Alger, Paris,
in the Republic of France, Engineer, do hereby declare the nature of this invention
to be as follows :-
My invention relates generally to elastic or pneumatic tyres for application to
the wheels of bicycles, tricycles and other wheeled vehicles. The improvement
may be used in conjunction with that class of pneumatic tyre in which the air bag
is protected from puncture by metal sheathings or coverings, but the invention is
also applicable to tyres in which the usual pneumatic cushion is replaced by radial
or concentric or other springs or by a coiled helical spring covered with rubber.
The objections to such metal sheathings or radial or concentric supporting
springs is that the softness and resilience of the air cushion is impaired or lost
while in the case of the endless helical spring in addition to the vibration due to
the open coils, there is insufficient adhesion to the road, the same objection
applying to the metal sheathed or protected pneumatic cushion.
My present invention is applicable to all of these different variations and allows
them to be used without being subject to the foregoing drawbacks.
The invention consists in interposing, between the outer cover and the metal,
(whether such metal take the form of radial springs, or of a spiral endless spring
of the shape of the tyre, or of a metal protector adapted to the ordinary pneumatic
tyre) a hollow rubber band containing air and forming an independent cushion,
which gives adhesion to the soil, softness and ease in the rolling, and which permits
the tyre to mould itself to all the unevenness of the pavement or country roads
while running no risk of becoming inefficient as it would require to be punctured
in several hundred places before it could become flabby.
This hollow band is composed of many successive cells, its security lying in the
multiplicity of the air chambers which it contains.
In applying my invention to a pneumatic cushion tyre protected from puncture
by a metal sheathing the arrangement would be as follows."
I would surround the tread or periphery of the air chamber of elastic rubber,
with a curved blade of protecting thin sheet metal.
This protecting blade of metal is placed upon a thickness of linen or other cloth,
which reaches to the outer edges of the outer envelope. In order to fix this metal
blade in its place it is covered by two other pieces of linen of which one edge is
free while the other edge is fixed to the corresponding edge of the first linen
covering. This disposition gives me a triple ply for strength and security, but I
do not confine myself to this as the number of layers of linen or other cloth may
be varied as well as the manner in which they cover and hold the metal blade in
position.
Between the outer envelope and the linen which covers the protecting metal
sheathing I place my secondary pneumatic cushion. This cushion is of a crescent
shape in cross section gradually diminishing in thickness towards each edge and
overlapping the protecting metal blade upon each side. On account of its crescent
shape, and without leaving any air space or producing any unevenness which would
make the tyre look rough, it completely fills out the space comprised between the
outer envelope and the linen covering of the protecting metal. The said cushion.

page_text: is composed of a thickness of rubber, upon the under surface of which has been
placed during the moulding, a series of rubber ledges running crosswise, this
disposition forming a series of open air chambers between the ledges, and being
closed on the inner side by a thin layer of rubber of which the inner surface
adheres firmly to the ledges. I thus obtain a series of closed airtight cells filled
with air so that the cushion acts as a supplementary elastic covering giving full
adhesion to the soil, and moulding itself to all the inequalities of the road while at
the same time it practically cannot become inefficient, for, even were a number of
the cells in the cushion to be pierced by nails or tacks, the piercing agent could
not in the first place reach the inner air chamber on account of the protecting
metal, and in the second place the cushion would not become flabby or have to be
replaced as the elastic inner walls perfectly sustain it.
When applied to a tyre formed by a series of metal springs or by an endless
spiral spring as above mentioned, the action of this secondary or auxiliary cushion
is, in all essential respects the same and needs no detailed description.
My invention is applicable to all descriptions of vehicle wheel tyres. The
dimensions and proportions are however variable according to the particular
application.
Dated the 18th day of November 1905
Improvements in Elastic or Pneumatic Tyres for the Wheels of
Vehicles.
I CHARLES LEWIS HEERMANN DE HUNDERTMARK of 10 Rue d'Alger, Paris,
in the Republic of 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 and accompanying
drawings:
My invention relates generally to elastic or pneumatic tyres for application to
the wheels of bicycles, tricycles and other wheeled vehicles. The improvement
may be used in conjunction with that class of pneumatic tyre in which the air bag
is protected from puncture by metal sheathings or coverings, but the invention is
also applicable to tyres in which the usual pneumatic cushion is replaced by radial
or concentric or other springs or by a coiled helical spring covered with rubber.
The objections of such metal sheathings or radial or concentric supporting springs
is that the softness and resilience of the air cushion is impaired or lost while in
the case of the endless helical spring in addition to the vibration due to the open
coils there is insufficient adhesion to the road, the same objection applying to the
metal sheathed or protected pneumatic cushion.
My present invention is applicable to all of these different variations and allows
them to be used without being subject to the foregoing drawbacks.
The invention consists in interposing, between the outer cover and the metal,
(whether such metal take the form of radial springs, or of a metal protector
adapted to the ordinary pneumatic tyre) a hollow rubber band containing air and
forming an independent cushion, which gives adhesion to the soil, softness and ease
in the rolling, and which permits the tyre to mould itself to all the unevenness
of the pavement or country roads, while running no risk of becoming inefficient as
it would require to be punctured in several hundred places before it could become
flabby.

page_text: This hollow band is composed of many successive cells, its security lying in the
multiplicity of the air chambers which it contains.
In applying my invention to a pneumatic cushion tyre protected from puncture
by a metal sheathing the arrangement would be as follows.
I would surround the tread or periphery of the air chamber of elastic rubber,
with a curved blade of protecting thin sheet metal.
This protecting blade of metal is placed upon a thickness of linen or other cloth
which reaches to the outer edges of the outer envelope. In order to fix this metal
blade in its place it is covered by two other pieces of linen of which one edge is
free while the other edge is fixed to the corresponding edge of the first linen
covering. This disposition gives me a triple ply for strength and security, but I
do not confine myself to this as the number of layers of linen or other cloth may
be varied as well as the manner in which they cover and hold the metal blade in
position.
Between the outer envelope and the linen which covers the protecting metal
sheathing, I place my secondary pneumatic cushion. This cushion is of a crescent
shape in cross section gradually diminishing in thickness towards each edge and
overlapping the protecting metal blade upon each side. On account of its crescent
shape, and without leaving any air space or producing any unevenness which would
make the tyre look rough, it completely fills out the space comprised between the
outer envelope and the linen covering of the protecting metal. The said cushion
is composed of a thickness of rubber, upon the under surface of which has been
placed during the moulding, a series of rubber ledges running crosswise, this
disposition forming a series of open air chambers between the ledges, and being
closed on the inner side by a thin layer of rubber of which the inner surface
adheres firmly to the ledges. I thus obtain a series of closed airtight cells filled
with air so that the cushion acts as a supplementary elastic covering giving full
adhesion to the soil, and moulding itself to all the inequalities of the road while at
the same time it practically cannot become inefficient, for, even were a number of
the cells in the cushion to be pierced by nails or tacks, the piercing agent could not
in the first place reach the inner air chamber on account of the protecting metal,
and in the second place the cushion would not become flabby or have to be replaced
as the elastic inner walls perfectly sustain it.
When applied to a tyre formed by a series of metal springs or by an endless
spiral spring as above mentioned, the action of this secondary or auxiliary
cushion is, in all essential respects the same and needs no detailed description.
My invention is applicable to all descriptions of vehicle wheel tyres.
dimensions and proportions are however variable according to the particular
application.
The
To render my invention clearly understood 1 will now proceed to describe the
same with reference to the annexed sheet of illustrative drawings which represent
my improved protecting hollow cushion applied in conjunction with an ordinary
pneumatic tyre.
Fig. 1 is a cross section of the improved tyre in position on the rim of a
wheel.
Fig. 2 is a view of a portion of the tyre and wheel rim at right angles to Fig. 1
partly in side elevation and partly in longitudinal section.
A indicates the rim of the wheel which might be of any convenient description.
The drawings indicate a wooden rim but it might be of metal or other suitable
substance. B is the ordinary inflatable air bag. This bag is covered on its upper
penphery, that is to say on the part which does not rest on the rim by a strip c of
linen or other suitable fabric as shown in the drawings. Upon this strip c is placed
a protecting curved shield ring C of thin sheet metal or other suitable material
such for example as celluloid, "viscoid" or the like, the ring being interrupted in
its circumference so that the two abutting or overlapping ends are capable of
movement towards and from each other so as to suit the expansion of the air
chamber or bag. Between the outer cover D and the protecting curved shield C

page_text: I place my improved cellular air cushion E. It will be seen that the thickness of
this cellular cushion diminishes towards each margin or edge and that it overlaps
the shield C on each side. Owing to its crescent shape in cross section it fills the
space between the outer cover and the protecting shield C without any unevenness
or unsightliness. The said cellular air cushion is composed of a curved thickness e
of rubber on the under side of which I form in the course of manufacture a series
of cross ribs e between which appear an equal number of spaces e² which are sealed
up by a thin layer of rubber e cemented to the under surface and adhering air tight
to the cross ribs and the outer edges of the cushion. Thus I obtain a series of
sealed chambers containing air and running all round the cushion, the auxiliary
elastic tread thus obtained giving proper adhesion to the road and softening the
shocks created by the irregularities of the ground. At the same time it may be
pointed out that the tyre is practically uncollapsable as even if several of the cells
in the cushion E were punctured or cut by thorns, nails or other objects, the
pneumatic properties of the cushion and tyre would not be appreciably interfered
with or diminished. The metal or other shield C prevents puncture or cutting of
the air bag B, and even if a cell or several cells in the cushion E were punctured,
the cross ribs or ridges e¹ would support the tread and prevent such puncture from
having any appreciable effect on the smooth running of the tyre.
The outer cover D is made so that it will not stretch and as a result the cellular
air cushion C is compressed by the inflation of the air bag B, such compression
causing the cushion C to become properly a pneumatic tyre, the air in the cells
being under compression. To render the cover D of this non-elastic nature, the
inuer portion of the cover is composed of several layers d of linen or other suitable
fabric which has been well stretched and upon this I lay an outer thickness d¹
of rubber to constitute the tread which runs in contact with the road.
It will be easily understood that in a tyre constructed in this manner, the
pressure of air in the air bag B is exerted against the shield C without let or
hindrance as the protecting ring C does not form a complete circle but as already
set forth is cut or interrupted in its circumference so that it can expand and so
transmit the pressure in a uniform manner to the cellular cushion. The latter is
thus compressed against the interior of the non-elastic outer cover D the cellular
cushion being thus in its turn compressed. The air cells being thus compressed
necessarily diminish in volume and the contained air being thus compressed
the cellular cushion thus constitutes a species of secondary pneumatic tyre.
When the elastic properties of the tyre are derived not from an inflated air bag
as shown in the drawings but from a continuous coiled spring or series of springs
round the tyre as herein before set forth, the functions of the cellular air cushion
remain the same in all essential points and it is therefore unnecessary to recapitulate
their properties under these varied conditions.
My improved cellular air cushion may be applied to the tyres of all descriptions
of wheels for road vehicles, the sizes and proportions varying according to the
particular application.
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.) The improved elastic wheel tyre substantially as herein before described and
shown.
(2.) The improved elastic tyre consisting of the combination of an inner elastic
pueumatic bag or spring or arrangement of springs with a non-elastic outer cover
there being interposed between these a cellular air cushion composed of an outer
thickness of elastic rubber with a series of cells formed by dividing cross ribs and
an applied sealing thickness of rubber beneath so as to close up the said cells
hermetically, all arranged and acting substantially as herein before described and as
illustrated.
(3.) The improved pneumatic tyre composed essentially of the inner inflatable

page_text: air bag B, the curved protecting shield C, interrupted in its circumference so as
to yield to the outward pressure of the air bag, the cellular air cushion, and
the non-elastic outer cover D all arranged and acting substantially as described and
shown.
Dated this 4th day of May 1896.
For the Applicant,
E. K. DUTTON & Co.,
5 John Dalton Street, Manchester, Chartered Patent Agents.