Improvements in Pneumatic Tyres.
Year: 1899

page_text: Date of Application, 31st Jan., 1899-Accepted, 11th Mar., 1899
COMPLETE SPECIFICATION.
Improvements in Pneumatic Tyres.
I, GEORGE HENRY CLARK, of 123, Pearl Street, Boston, in the County of Suffolk,
and State of Massachusetts, United States of America, Manufacturer of Shoe
Patterns. 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 pneumatic wheel tyre shown in my prior Patent No. 8107 of 1898, filed
April 4, 1898 comprises essentially an air tube and a tread strip at the tread
side of said air tube which is incorporated into and forms a part of the tyre,
said strip serving as a protecting strip to provide against puncturing the air
tube, and in practice said tread strip is made of cork.
Cork, in its natural state, is more or less cellular or porous, and the cheaper
qualities are more cellular or porous than the costly qualities, and in practice I
have found in manufacturing the tyre, that the rubber composing the air tube
enters the cells or pores of the cork. more particularly when the tyre is being
first blown up prior to being vulcanized, yet also during the process of vulcani-
zation, and in many instances an imperfect or leaky air tube is the result, which
of course destroys the commercial value of the tyre; and I have also found in
practice that when the cells or pores of the cork have thus become filled with
rubber, that the cork strip is materially stiffened and weighted, and as a con-
sequence it will less readily respond to compression, while its increased weight
is disadvantageous. Furthermore I have found in practice that the rubber com-
posing the outer covering also enters the cells or pores of the cork, which like-
wise stiffens and weights the cork strip, and although the rubber composing
the outer covering is not usually of the same quality as the rubber composing
the air tube, yet its effect on the cork strip is substantially the same.
This invention has for its object to improve the construction of a pneumatic
wheel tyre having a cellular or porous tread strip at the tread side of the air
tube, such as cork, sponge rubber, loosely woven fabric etc. whereby the rubber
which forms the essential element of the tyre, is prevented from entering the
cells or pores of said tread strip, especially the rubber composing the air tube,
thereby enabling the production of a pneumatic wheel tyre having vulcanized
in it at the tread side of the air tube a cellular or porous tread strip, i.e. a tread
strip provided with numerous air cells. In carrying out this invention a sub-
stantially imperforate strip of material is interposed between the air tube and
the cellular or porous tread strip which effectually prevents the rubber CODI-
posing the air tube from entering the cells or pores of said tread strip, and another
substantially imperforate strip of material is interposed between said cellular or
porous tread strip and the outer covering, which likewise effectually prevents the
rubber composing the outer covering from entering the cells or pores of said tread
strip. The substantially imperforate strip which is interposed between the tread strip
and the air tube may be composed of a narrow strip of closely woven canvas, made
as wide or wider than the tread strip, or it may be made wide enough to entirely
enclose the air tube and in such case to serve as a sheath therefor, and the
substantially imperforate strip which is interposed between said tread strip and

page_text: the outer covering may likewise be made of any suitable width. Closely woven strips
of canvas may be employed as the substantially imperforate strips, and to ren-
der them substantially imperforate they may be treated upon one or both sides
with a coating of rubber or rubber compound which is worked into the strips
as for instance with heavy rolls, yet said strips may be made imperforate in
any other suitable way, so far as my invention is concerned. It is only necessary
to render the strips imperforate for that portion of their width equal to the
width of the tread strip, yet of course they may be rendered imperforate for
their entire width. Either or both substantially imperforate strips will be used
but I prefer to use both. The aforesaid parts are vulcanized together. My
invention however is not limited to the employment of a substantially imperforate
strip to produce the results desired as desire to broadly include within the
scope of this invention any means whereby the rubber is prevented from enter-
ing the cells or pores of the tread strip. I prefer, however, to use a strip or
strips which are constructed or rendered substantially imperforate, because said
strips may be made non-extensible and thereby used to re-enforce, and strengthen
the tread strip and keep it from extending or stretching when the tyre is inflated.
In my patent above referred to the tread strip is secured to a non-extensible
strip of material, and is thereby prevented from stretching when the tyre is inflated,
and my present invention is also intended to include such a non-extensible
strip of material when rendered substantially imperforate whereby the results
herein sought may be obtained.
The invention also has for its object to construct a tread-strip for pneumatic
wheel tyres which shall be light and resilient, and yet may be made of con-
siderable thickness and when incorporated in the tyre at the tread side of the
air tube will serve as a protector to prevent the air tube from being easily
punctured.
In accordance with this part of my invention the tread strip is composed
essentially of two strips of material one of which is flexible but not compressible
to any great extent, to thereby present a firm body, as cork for instance, and
the other of which is not only flexible but very yielding or elastic as sponge
rubber for instance, and said two strips of material are laid one upon the other
and secured together for their entire length. It is preferable to place the strip
of cork, upon the inside and the strip of sponge rubber upon the outside, as in
such case the strip of cork serves as a firm foundation for the strip of sponge
rubber.
The compound strip thus composed of a strip of cork and a strip of sponge
rubber, secured together for their entire length, will be incorporated in the tyre
at the tread side of the air tube, but when the air tube is inflated such com-
pound strip will be extended in the direction of its length to such an extent as
to break the cork strip at intervals, unless means are provided to prevent such
result, and also when the air tube is inflated the strip of sponge rubber will be
more or less compressed, and its yielding quality diminished, unless means are
provided to prevent such result, consequently I have secured to the compound
strip for its entire length, a strip of substantially non-extensible material, which
effectually prevents said compound strip from being extended when the air tube
is inflated, and for the accomplishment of such result said non-extensible strip
may be applied to either the outside or inside of said compound strips, but to
provide against compressing the strip of sponge rubber said non-extensible strip
will be applied to the inside of the compound strip.
In practice however I prefer to employ two substantially non-extensible strips
of textile material, and apply one to the inside and the other to the outside of
the compound strip, thus enclosing said compound strip in a substantially non-
extensible jacket or sheath. Such a tread strip is light and flexible and may be
made of considerable thickness and the strip of sponge rubber or other yielding
material provides a soft and yielding or compressible tread.
The invention also has for its object to construct a pneumatic wheel tyre which

page_text: may be inflated by means of an air forcing device attached to or having as a
co-operative part of it, a tubular needle, commonly called a hypodermic needle,
which is adapted to be thrust into the tyre, thereby obviating the necessity of
employing a valve.
In accordance with this part of my invention the tyre is provided with a
sealed sack or pocket containing a sealing compound, and said sealed sack or
pocket is applied to the inner tube, and is adapted to be perforated by a tubular
or hypodermic needle which is attached to a suitable air forcing device. When
the needle is withdrawn the sealing compound closes the perforation. In order
that the location of said sealed sack or pocket may be known an external in-
dication is formed or provided on the tyre.
The sealed sack or pocket is preferably composed of two pieces of rubber,
secured together at the edges, and containing a sealing compound, which for
instance may be composed essentially of linseed oil associated with gum and other
ingredients, the sealing compound being of the nature or character that will
not harden or become destroyed by heat when the tyre is subjected to the usual
process of vulcanization.
The sealed sack or pocket is preferably applied to the inside of the air tube,
being cemented to the wall thereof, and when so applied the tubular needle will
pass entirely through it when introduced for the purpose of inflating or deflating
the tyre.
When the sealed sack or pocket is applied to the interior of the air tube its
inner wall will be made convex, so as to flatten more or less as the tyre is inflated,
and tliereby cause the sealing compound to fill and close the perforation
In the accompanying drawing:
Figure 1 shows a cross section of a pneumatic wheel tyre embodying this
invention.
Figure 2 is an enlarged sectional detail of the tread strip. Figure 3 is a side
view of a portion of the tyre.
Figure 4 is a cross sectional detail of the sealed sack or pocket.
Figure 5 is a cross section of a pneumatic wheel tyre having a tread strip of
cork. instead of sponge rubber shown in Figure 1. Figure 6 is a side view on
a smaller scale of the tread strip. Figure 7 is a detail showing a portion of a
strip of material and means employed for rendering it substantially imperforate.
Figure 8 is a detail showing said strip of material, a portion of which is rendered
substantially imperforate. Figure 9 shows a cross section of a portion of a
cellular or porous tread strip showing rubber contained in the cells or pores
thereof, which stiffens the strip and weakens the air tube.
a represents the air tube, which may be formed upon a mandril if desired. b
represents a sheath or covering enclosing said air tube. which is preferably made
of textile material and more or less extensible, as for instance it may be com-
posed of a strip of textile material cut off on the bias. c represents a substantially
imperforate strip which is disposed at the tread side of the air tube a.
d repre-
sents the tread strip of cork, sponge rubber, or other cellular or porous material,
it being represented in Figure 1, as composed of a foundation strip of cork d¹ and
a superimposed strip of sponge rubber and in Figure 5, as composed of a
strip of cork, yet it may be composed of any other cellular material, or fabric
woven or knit to produce cells. e represents a sheath or covering enclosing the
aforesaid parts, and f the outer covering. These parts are all attached together
by cement and may be secured by vulcanization, yet so long as they are attached
together and thereby held in fixed relation to each other the purposes of this
invention are accomplished.
The substantially imperforate strip c may be composed of textile material as
closely woven canvas for instance, coated with rubber or rubber compound on
one or both sides, which is worked into said strip by pressure in such way as to
render it substantially imperforate, yet my invention is not limited to rendering
the strip substantially imperforate in this particular way. In Figure 7, ¹ repre-

page_text: sents the closely woven fabric, and c² layers of rubber which are to be incorporated
in the fabric by heavy pressure, producing a substantially imperforate strip, such
as shown in Figure 8.
The imperforate strip c is interposed between the cellular tread strip and the
air tube, and will effectually prevent the rubber composing said air tube from
being blown into or otherwise caused to enter the cells or pores of said strip.
It is obvious that this imperforate strip e may be disposed contiguous to the
air tube, that is, between the air tube and the expansible sheath b, and sub-
stantially the same results will be produced, it only being necessary that said
imperforate strip shall be placed between the air tube and cellular strip.
It is obvious that the imperforate strip may be made as wide as desired,
and while herein shown as made a little wider than the tread strip, I desire it
to be understood that said strip c may be made of any width and even may com-
pletely enclose the air tube.
I desire also to have it understood that it is only essential that the imperforate
strip shall be made imperforate along that portion of its width between the
air tube and cellular strip, consequently the remaining portion or portions of said
strip
c need not be thus made imperforate, and if said strip should completely
enclose the air tube of course all that portion of it opposite or beneath the
cellular strip will be made imperforate. In any event such imperforate strip or
imperforate portion of a strip, or other means interposed between the air tube
and cellular strip, whereby the rubber will be prevented from entering the cells
or pores of the strip, comes within the spirit and scope of this invention.
The sheath e is also made of closely woven canvas, and that portion of it con-
tiguous the cellular strip is made substantially imperforate, as for instance, it
may be rendered substantially imperforate in the same manner as the strip cabove
referred to, and said sheath, or that portion of it which is made substantially
imperforate, will effectually prevent the rubber of the outer covering from enter-
ing the cells or pores of the cellular strip.
The strip c, if made non-extensible, will prevent the tread strip d from being
stretched when the tyre is inflated, and as such a result is important I prefer to
make the strip e non-extensible.
The compound tread-strip shown in Figure 1, is made circular and is composed
of two strips of material, one of which as d is made quite thick and presents a
flexible yet firm foundation strip to support the other strip 2 which is placed
upon and secured to it for its entire length.
The strip may be composed of cork, as such material is light yet flexible and
does not yield to any great extent and consequently will serve to hold in normal
shape the strip which is placed upon and secured to it. The strip dis
flexible and very yielding and may be composed of sponge rubber, as such
material I find to be well suited for the purpose.
These two strips and will be cemented and vulcanized together or may be
attached together for their entire length in any other suitable way.
To prevent the compound strip thus produced from stretching and thereby
breaking the strip or cork at intervals, and also to prevent materially changing
the normal shape of the compound strip, the strip or strips of substantially non-
extensible textile material will be secured for the entire length to the outside of
one of the strips or it may be to both of the strips.
Providing a tread-strip with a substantially non-extensible strip or strips, as
described, enables the tread-strip to retain its normal shape as the air tube is
inflated, and also prevents extension of said tread-strip and also prevents com-
pression of the yielding or elastic strip by reason of internal pressure, which is
important.
n, Figure 1, represents a sealed sack or pocket of small dimensions which is
secured to the interior of the tyre, as for instance, it may be composed of two
small circular or other shaped pieces n¹, n² of rubber (see Figure 4), secured to-
gether at their edges only, and containing between them a quantity of sealing

page_text: compound n³, which will not become hardened or destroyed by heat during the
ordinary process of vulcanizing the tyre.
The sealed sack or pocket n is attached to the interior of the air tube a and
when thus secured in place it may be readily perforated by an ordinary tubular
needle, such for instance, as a hypodermic needle especially adapted for the
purpose, which is attached to or forms a part of an air forcing device.
When the sealed sack or pocket is applied to the interior of the air tube, its
inner wall will be made convex, as shown and said convex inner wall will be.
more or less flattened when the tyre is inflated, by the pressure of the air com-
tained in the air tube.
As said convex inner wall is flattened, it will be seen that the perforation
which may be made by the needle will close, and will be sealed by the sealing
compound. It will also be seen that as said convex inner wall is flattened by
pressure upon or against it, the sealing compound will be more or less compressed
and forced to enter and seal the perforations.
When the needle is introduced it will pass through the outer covering of the
tyre, and through the wall of the air tube and through both walls of the sealed
sack or pocket and through the sealing compound contained in said sack. With
the needle thus introduced the tyre may be inflated or deflated and when the
needle is withdrawn, the sealing compound will act to seal the perforations pro-
duced by the introduction of the needle.
On the exterior of the tyre a small circle m may be formed to indicate the
location of the sealed sack or pocket, or any other sort of an indication may be
provided for the accomplishment of this result.
I desire it to be understood that I do, not intend to limit my invention to any
particular form, construction or location of the sealed sack or pocket.
By providing a sealed sack or pocket composed of two pieces or walls secured
together at their edges and containing a sealing compound it will be seen that
when the tubular needle is inserted both pieces or walls of the sack or pocket will
be perforated and by slightly withdrawing the needle the perforation in the
inner wall may be closed and sealed before the needle has been withdrawn from
the outer wall and as a consequence the air tube may be sealed before the needle
has been totally withdrawn from the tyre, that is to say, the perforation in the
inner wall of the sealed sack or pocket may be closed and sealed in advance of
the other perforations made by the needle, which is an important feature.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:-
1. In a pneumatic wheel tyre, an air tube, a cellular or porous tread strip at
the tread side thereof, and means interposed between said air tube and tread-
strip for preventing the rubber composing the air tube from entering the cells
or pores of said tread strip, said parts being attached together, substantially as
described.
2. In a pneumatic wheel tyre, an air tube, a cellula or porous tread-strip at
the tread side thereof, and a substantially imperforate strip interposed between said
air tube and tread strip, which prevents the rubber composing said air tube from
entering the cells or pores of said tread-strip, said parts being attached together,
substantially as described.
3. In a pneumatic wheel tyre, an air tube, a tread strip at the tread side thereof
having numerous air cells and a non-extensible strip of textile material made
substantially imperforate interposed between said air tube and tread strip, said
parts being attached together, substantially as described.
4. In a pneumatic wheel tyre, an air tube, a cellular or porous tread strip at the
tread side of it and an outer covering, means interposed between said tread strip
and air tube for preventing the rubber composing the air tube from entering the

page_text: cells or pores of said tread strip and means interposed between said tread strip
and the outer covering for preventing the rubber composing the outer covering
from entering the cells or pores of said tread strip said parts being attached
together, substantially as described.
5. In a pneumatic wheel tyre, an air tube, a cellular or porous tread strip at the
tread side of it and an outer covering and a substantially imperforate sheath en-
closing said air tube and tread strip thereon which is contained within said outer
covering, substantially as described.
6. In a pneumatic wheel tyre. a cellular or porous tread strip at the tread side
of the air tube, and a substantially imperforate tubular jacket enclosing said tread
strip and secured thereto, substantially as described.
7. In a pneumatic wheel tyre, an air tube, a substantially imperforate jacket in
which it is enclosed, a cellular or porous tread strip at the tread side of said enclosed
air tube, and an outer covering, said parts being attached together, substantially
as described.
8. In a pneumatic wheel tyre, an air tube, a cellular or porous strip and means
interposed between said air tube and said strip for preventing the rubber com-
posing the air tube from entering the cells or pores of said strip, said parts being
attached together, substantially as described.
9. In a pneumatic wheel tyre, an air tube, a cellular or porous strip and a strip of
textile material made substantially imperforate and means interposed between said
air tube and said strip for preventing the rubber composing the air tube from
entering the cells or pores of said strip, said parts being attached together, sub-
stantially as described.
10. In a pneumatic wheel tyre, an air tube, a cellular or porous strip and an
outer covering and a substantially imperforate sheath enclosing said air tube, and
cellular strip which is contained within said outer covering, substantially as de-
scribed.
11. In a pneumatic wheel tyre, an air tube, a substantially imperforate jacket
enclosing it, a cellular or porous layer and an outer covering, substantially as
described.
12. In a pneumatic wheel tyre, a circular tread-strip at the tread side of the air
tube consisting of a flexible strip and a yielding flexible strip secured together and
a substantially non-extensible strip of textile material secured to the said tread-
strip, substantially as described
13. In a pneumatic wheel tyre, a circular tread-strip at the tread side of the air
tube consisting of a flexible strip and a yielding flexible strip secured together
and a substantially non-extensible jacket enclosing said tread-strip, substantially as
described.
14. In a pneumatic wheel tyre, a circular tread-strip at the tread side of the air
tube consisting of a strip of cork and a strip of sponge rubber, one placed upon the
other and secured together, substantially as described.
15. In a pneumatic wheel tyre, a tread-strip at the tread side of the air tube
consisting of an inside strip of cork and an outside strip of sponge rubber secured
together, substantially as described.
16. In a pneumatic wheel tyre, a tread-strip at the tread side of the air tube con-
sisting of an inside strip of cork and an outside strip of sponge rubber secured
together, and a substantially non-extensible strip of textile material secured to
said tread-strip, substantially as described.
17. In a pneumatic wheel tyre, a strip of yielding flexible material at the tread
side of the air tube and a strip of substantially non-extensible textile material
interposed between said yielding strip and the air tube, whereby compression of
said yielding strip is prevented when the air tube is inflated, substantially as
described.
18. In a pneumatic wheel tyre, a strip of yielding flexible material at the tread
side of an expansible air tube and a strip of substantially non-extensible textile
material interposed between said yielding strip and said expansible air tube, where-

page_text: by compression of said yielding strip is prevented when said air tube is expanded,
substantially as described.
19. In a pneumatic wheel tyre, a strip of yielding flexible material at the tread
side of the air tube and a strip of substantially non-extensible textile material
interposed between said yielding strip and the air tube, whereby compression of
said yielding strip is prevented when the air tube is inflated, and a suitable cover-
ing enclosing said parts, substantially as described.
20. In a pneumatic wheel tyre, an expansive air tube, an elastic strip at the
tread side of it and a strip of substantially non-extensible material interposed
between said air tube and tread strip to prevent changes in the inherent elasticity
of the tread strip, substantially as described.
21. In a pneumatic wheel tyre, a practically non-extensible air tube and an
inherently resilient cover therefor composed of a layer of sponge rubber having a
suitable resilient or elastic tread surface, said covering having its tread portion of
a thickness to prevent access to the non-extensible air tube, of any ordinary pune-
turing means, the said non-extensible air tube serving to prevent changes in the
inherent elasticity of the cover, substantially as described.
22. A pneumatic wheel tyre having a sealed sack or pocket containing a sealing
compound, applied to the air tube, substantially as described.
23. A pneumatic wheel tyre having a sealed sack or pocket containing a sealing
compound applied to the air tube and having an external indication by which the
location of said sealed sack or pocket may be determined, substantially as described.
24. A pneumatic wheel tyre having a sealed sack or pocket containing a sealing
compound applied to the interior of the air tube, substantially as described.
25. A pneumatic wheel tyre having applied to its air tube a sealed sack or pocket
composed of two pieces secured together at their edges and containing a sealing
compound, substantially as described.
26. A pneumatic wheel tyre having applied to its air tube a sealed sack or
pocket composed of two pieces secured together at their edges and containing a
sealing compound, both walls of said sealed sack or pocket being perforated by
the tubular needle when inflating or deflating the tyre, and the perforations being
thereafter closed by the sealing compound, substantially as described.
27. A pneumatic wheel tyre having a sealed sack or pocket containing a sealing
compound, applied to the interior of the air tube, the inner wall of said sealed sack
or pocket being acted upon by the pressure of air in the tyre to cause the sealing
compound to close any perforations in said sack, substantially as described.
28. A pneumatic wheel tyre having a sealed sack or pocket containing a sealing
compound, applied to the interior of the air tube, the inner wall of said sealed sack
or pocket being convex, and flattening more or less as the tyre is inflated, sub-
stan fially as described.
Dated this 31st day of January 1899.
HASELTINE LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.