Improvements in Pneumatic Tyres
Year: 1897

page_text: Date of Application, 22nd Nov., 1897
Complete Specification Left, 8th Feb., 1898-Accepted, 27th Aug., 1898
PROVISIONAL SPECIFICATION.
Improvements in Pneumatic Tyres
I, UZZIEL PUTNAM SMITH, of 3126, Rhodes Avenue, Chicago, Cook County,
Illinois, United States of America, Inventor, do hereby declare the nature of
this invention to be as follows:-
The object of my invention is to provide a simple, economical and efficient
self closing pneumatic tyre, and the invention consists in the features, combina-
tions and details of construction, hereinafter described.
In the art to which this invention relates it is a matter of common knowledge
that pneumatic tyres as usually constructed and designed for bicycles and other
wheels are seriously objectionable owing to the fact that the inflating fluid will
escape when the tyre is punctured. Various constructions have heretofore been
designed with a view of obviating this objection but all of such constructions are
more or less imperfect from the fact that they do not prevent the fluid from
escaping at all times. In some instances rubber under compression has been
employed for the purpose of producing a self puncture closing tyre, reliance for
this purpose being placed upon the fact that, if rubber held under compression
is punctured, the orifice will instantly close as the puncturing instrument or
object is withdrawn.
The objection to such class of tyres which have heretofore been constructed
rests in the fact that such compressed rubber is cemented to a practically non-
extensible fabric and forms a compound fabric so that the non-extensible fabric,
to which the rubber was cemented, held the puncture open some distance from
the surface and permitted the air to gradually work its way through the puncture.
By cementing the compressed rubber to the non-extensible fabric the resiliency
of the tyre was also impaired or diminished for the reason that the local cushion-
ing effect of rubber was minimized and the compound material between the air
cushion and the ground acted as a lever to somewhat retard the free return of
the materials to their normal positions.
The chief objects of this invention are to entirely obviate the objections above
cited to provide an improved pneumatic tyre with a healing strip formed of
rubber held constantly under compression and so arranged that at all times the
compressible quality of the rubber is practically free to act and automatically
close punctures, thus providing a simple, economical and efficient means for
effectually preventing the leakage of the inflating fluid; to obtain the maximum
resiliency in the tyre, and finally to secure a stronger and more durable tyre, one
that may be readily removed or repaired.
In constructing a tyre in accordance with my invention I use an outer casing
and provide it with an inner air tube which forms the case for holding the fluid
under pressure. The outer casing and the inner inflating tube may be of any
desired construction and formed of any material commonly used in the manu-
facture of pneumatic wheel tyres or which will fulfil the conditions required in this
class of articles. I prefer, however, to make the outer casing and the inner tube of

page_text: rubber or rubber compound and canvas possessing such qualities as will enable
the tyre to retain the inflating fluid introduced therein under the desired pressure.
The tread portion of the tyre is provided with a healing strip composed of soft
vulcanized rubber which is compressed laterally and held under compression for
the purpose of automatically and instantly closing any punctures which may be
made therein as will be hereinafter more fully described, and which is located
preferably outside of the air tube and is covered by the material forming a part
of the outer casing.
To keep the healing strip under compression, I provide a relatively thin strip
of vulcanized rubber and place the same under tension by stretching it, and,
while in this stretched condition, secure it to one surface of the healing strip
which is a piece of soft vulcanized rubber of the desired thickness. After the
strip of rubber is secured to the healing strip, the stretched condition
is relieved and its retractile power acts to laterally compress or con-
dense the healing strip. If these united parts are not held flat by
some extraneous force, they will immediately curl or curve up. The
combined strip thus produced is then secured at its lateral edges to a strip
of practically non-extensible fabric by first securing one edge and then carrying
the strip around the combined rubber strip and securing it at the other edge so
that a substantially flattened or slightly concaved body of compressed material is
produced and the non-extensible fabric between the edges of the healing strip is
substantially free or disconnected. In this way, the compressed healing body is
practically a free agent acting mechanically and perfectly to heal any puncture
which may be made therethrough; or, in other words, so close the puncture that
the fluid which is held in the interior annular chamber cannot escape.
In securing the healing strip to the non-extensible fabric, various methods may
be employed for instance, the healing strip may first be secured at its edges
to the non-extensible strip so as to cause it to assume an arch-shape. The thin
strip of rubber may then be stretched and cemented to the arched surface, in
its stretched condition, so that when the tension is released its retractile force
acts to compress the rubber and depress the arch of the healing strip to a sub-
stantially flat or slightly convex position, as may be desired. The healing
portion thus prepared and secured to the non-extensible portion is preferably
covered on the exterior by the material forming a part of the outer casing so as
to form what is commonly known as a single tube tyre.
When the tyre is inflated, the body of compressed rubber is forced outwardly.
As the tyre is inflated, the compression on the outer side of the healing strip
becomes somewhat lessened by stretching and the inner side somewhat addition-
ally compressed--the whole acting to obtain what might be termed a healing
strip of rubber, substantially and equally compressed on both surfaces and
throughout its body portion. In this way any puncture therein will be auto-
matically and immediately closed as soon as the puncturing object is withdrawn.
It will be obvious that under all conditions, so long as the compressed healing
portion is left practically free to act independently of the non-extensible fabric
in the tyre, that it will automatically and instantly act to close all ordinary
punctures.
I may apply my invention to a double tube tyre, in which case the healing
strip is first secured at its lateral edges only to a non-extensible fabric so as to
make the healing strip form a substantial arch. An air tube preferably formed
of soft vulcanized rubber, is then provided and its outer peripheral surface
stretched or placed under tension and closely united by means of cement to the
arched surface of the healing strip, so that when it is released its retractile.force
will act to somewhat lessen the arch of the healing strip by compressing the
surface of the arch. The annulus thus produced may be used as an inner tube
for a double tube tyre and placed in an enclosing sheath of the desired construction,
so that when placed in such sheath the arch of the healing strip extends towards
the longitudinal centre of the tyre, and when such tyre is inflated the arched

page_text: healing strip is forced against the inclosing sheath and its position inverted, so
that it practically forms an oppositely shaped arch acting to compress both sides
and the entire body of the healing strip in a uniform manner.
When it is desired to use my invention in connection with a single tube tyre,
the edges may be secured to the inner surface of the sheath or fabric forming
the air tube. An inner surface of soft vulcanized rubber may be provided or not,
as may seem desirable or necessary.
While I have described my invention with more or less minuteness as regards
details of construction and arrangement, and as being embodied in certain precise
forms, it will be understood that I do not desire to be limited strictly thereto.
On the contrary, I contemplate all proper changes in form, construction and
arrangement, so long as I do not depart from the spirit of the invention which
consists principally in holding a body of rubber under lateral compression and
leaving its main or body portion substantially free so that it may exert its
compressible qualities at all times.
I, UZZIEL PUTNAM SMITH, of 3126, Rhodes Avenue, Chicago, Cook County,
Illinois, United States of America, Inventor, 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 object of my invention is to provide a simple, economical and efficient
self closing pneumatic tyre, and the invention consists in the features, combina-
tions and details of construction, hereinafter described.
In the art to which this invention relates it is a matter of common knowledge
that pneumatic tyres as usually constructed and designed for bicycle and other
wheels are seriously objectionable owing to the fact that the inflating fluid will
escape when the tyre is punctured. Various constructions have heretofore been
designed with a view of obviating this objection but all of such constructions are
more or less imperfect from the fact that they do not prevent the fluid from
escaping at all times. In some instances rubber under compression has been
employed for the purpose of producing a self puncture closing tyre, reliance for
this purpose being placed upon the fact that, if rubber held under compression
is punctured, the orifice will instantly close as the puncturing instrument or
object is withdrawn.
The objection to such class of tyres which have heretofore been constructed
rests in the fact that such compressed rubber is cemented to a practically non-
extensible fabric and forms a compound fabric so that the non-extensible fabric,
to which the rubber was cemented, held the puncture open some distance from
the surface and permitted the air to gradually work its way through the puncture.
By cementing the compressed rubber to the non-extensible fabric the resiliency
of the tyre was also impaired or diminished for the reason that the local cushion-
ing effect of rubber was minimized and the compound material between the air

page_text: cushion and the ground acted as a lever to somewhat retard the free return of
the materials to their normal positions.
The chief objects of this invention are to entirely obviate the objections above
cited; to provide an improved pneumatic tyre with a healing strip formed of
rubber held constantly under compression and so arranged that at all times the
compressible quality of the rubber is practically free to act and automatically
close punctures, thus providing a simple, economical and efficient means for
effectually preventing the leakage of the inflating fluid; to obtain the maximum
resiliency in the tyre, and finally to secure a stronger and more durable tyre, one
that may be readily removed or repaired.
In order that my invention may be clearly understood and freely carried into
effect, I will proceed to describe the same more fully with reference to the accom-
panying drawings.
In the said drawings Figure 1 is a transverse sectional view of one form of
pneumatic tyre in which my improvements are embodied and showing the tyre in
a deflated condition; Figure 2 a similar view showing the same construction of
tyre in an inflated condition; Figure 3 a detail view indicating the manner in
which the rubber is placed under compression; Figure 4 a detail view showing
the rubber placed under compression and held in such condition; and Figure 5
a sectional view of another type of tyre constructed in accordance with my
invention and in a deflated condition.
In constructing a tyre in accordance with my invention-as shown in
Figures 1, 2, 3, and 4-I use an outer casing D and provide it with an inner air
tube C which forms the case for holding the fluid-air-under pressure. The
outer casing and the inner inflating tube may be of any desired construction and
formed of any material commonly used in the manufacture of pneumatic wheel
tyres or which will fulfil the conditions required in this class of articles. I prefer,
however, to make the outer casing and the inner tube of rubber or rubber
compound and canvas possessing such qualities as will enable the tyre to retain
the inflating fluid introduced therein under the desired pressure. The tread
portion of the tyre is provided with a healing strip A composed of soft vulcanized
rubber which is compressed laterally and held under compression for the purpose
of automatically and instantly closing any punctures which may be made therein
as will be hereinafter more fully described, and which is-in the construction
shown in Figures 1 and 2-located preferably outside of the air tube and is
covered by the material forming a part of the outer casing.
To keep the healing strip under compression, as shown in Figures 1 and 2,
I provide a relatively thin strip B of vulcanized rubber and place the same under
tension by stretching it, and, while in this stretched condition, secure it to one
surface of the healing strip which is a piece of soft vulcanized rubber of the
desired thickness. After the piece of rubber B is secured to the healing strip,
the stretched condition is relieved and its retractile power acts to laterally com-
press or condense the healing strip. If these united parts are not held flat by
some extraneous force, they will immediately curl or curve up. The combined
strip thus produced is then secured at its lateral edge to a strip of practically
non-extensible fabric E, by first securing the edge a and then carrying the strip
around the combined rubber strip and securing it at the other edge a¹, so that
a substantially flattened or slightly concaved body of compressed material is
produced and the non-extensible fabric between the edges of the healing strip is
substantially free or disconnected. In this way, the compressed healing body
is practically a free agent acting mechanically and perfectly to heal any puncture
which may be made there through; or, in other words, to so close the puncture that
the fluid which is held in the interior annular chamber cannot escape.
In securing the healing strip to the non-extensible fabric, various methods
may be employed-for instance, the healing strip may first be secured at its edges
to the non-extensible strip so as to cause it to assume an arch-shape. The thin
strip of rubber B may then be stretched and cemented to the arched surface in its

page_text: stretched condition, so that when the tension is released its retractile force acts
to compress the rubber and depress the arch of the healing strip to a substantially
flat or slightly convex position, as may be desired. The healing portion thus
prepared and secured to the non-extensible portion is preferably covered on the
exterior by the material forming a part of the outer casing, as shown in
Figures 1 and 2, in which form it is shown as forming what is commonly known
as a single tube tyre.
When the tyre is inflated, the body of compressed rubber is forced outwardly
and the tyre assumes the shape shown in Figure 2. As the tyre is inflated, the
compression on the outer side of the healing strip becomes somewhat lessened
by stretching and the inner side somewhat additionally compressed-the whole
acting to obtain what might be termed a healing strip of rubber, substantially
and equally compressed on both surfaces and throughout its portion. In this way
any punctures made therein will be automatically and immediately closed as
soon as the puncturing object is withdrawn.
It will be obvious that under all conditions, so long as the compressed healing
portion is left practically free to act independently of the non-extensible fabric
in the tyre, that it will automatically and instantly act to close all ordinary
punctures.
In Figure 5 I have shown my invention in a second form as applied to a double
tube tyre, in which the healing strip A is first secured at its lateral edges a, a¹
only to a non-extensible fabric F, and the said strip being of greater width than
the distance between the points at which it is attached naturally assumes an
arched shape. The tube G is then stretched and while in its extended position
is firmly secured to the healing strip so that when the tube is released the tension
of the tube causes the healing strip to flatten against the non-extensible fabric.
The annulus thus produced may be used as an inner tube for a double tube tyre
and placed in an inclosing sheath H of the desired construction, so that when
placed in such sheath the arch of the healing strip extends towards the longi-
tudinal centre of the tyre, and when such tyre is inflated the arched healing strip
is forced against the inclosing sheath and its position inverted, so that it practi-
cally forms an oppositely shaped arch acting to compress both sides and the entire
body of the healing strip in a uniform manner.
When it is desired to use my invention as outlined when considering Figure 5
in connection with a single tube tyre, the edges a and a' may be secured to the
An inner surface
inner surface of the sheath or fabric forming the air tube.
of soft vulcanized rubber may be provided or not, as may seem desirable or
necessary.
While I have described my invention with more or less minuteness as regards
details of construction and arrangement, and as being embodied in certain precise
forms, it will be understood that I do not desire to be limited strictly thereto
or any more than is pointed out in the claims.
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. An inflatable wheel tyre having at its tread portion a laterally compressed
band of rubber connected at its edges only to a non-extensible strip for the
purposes specified.
2. An inflatable wheel tyre having a tread portion of rubber under compression
and connected at its lateral edges only to a non-extensible fabric passed around
one side thereof and on the opposite side connected to a relatively thin sheet or
tube of rubber which acts to compress one side of the tread portion, substantially
as described.
3. An inflatable wheel tyre of the kind claimed in Claim 1 having a tread
portion forming in cross section a chord when the tyre is deflated, substantially
as described with reference to Figures 1 and 5 of the accompanying drawings.

page_text: 4. A pneumatic tyre having a self-puncture-closing tread portion composed of
a body of rubber constantly held under compression by the retractile force of a
layer of rubber secured to one surface thereof and disconnected between its
edges from all non-extensible material in the tyre, substantially as described with
reference to the accompanying drawings.
Noted this 7th day of Wa
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.