Improvements in and relating to Pneumatic Tyres for Wheels.
Year: 1896

page_text: Date of Application, 22nd Feb., 1896
Complete Specification Left, 23rd Nov.. 1896-Accepted, 6th Feb.. 1897
PROVISIONAL SPECIFICATION.
Improvements in and relating to Pneumatic Tyres for Wheels.
I, ALFRED HENRY CROCKFORD, of 26 Overy Street, Dartford, in the County
of Kent, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to pneumatic tyres for the wheels of bicycles, tricycles and
other vehicles, and its chief object is to ensure more effectually than heretofore the
fluid-tightness of the inner or air tubes of such tyres.
It is well known that, when such tyres are in use, the internal air-pressure
diminishes more or less rapidly either by reason of the porosity of the india-rubber
and the consequent passage of the air through the same, or by reason of the leakage
of air through small punctures formed therein the presence of which is not easily
ascertainable.
Now by my invention I am enabled to make an inner or air tube for a pneumatic
tyre which will retain the air therein at the desired pressure for a much longer period
than those as heretofore made, and notwithstanding the formation therein of any
sinall punctures or even such punctures as would render temporarily useless the air
tubes as hitherto used.
I have discovered that the pressure in the air-tube of a pneumatic tyre will be
maintained for a much longer period of time than heretofore if such tube is treated
internally with or contains a suitable liquid or other substance or mixture of substances
in such a condition that the same will efficiently close or stop up any pores or small
punctures in the tube.
I find it advantageous to introduce into the inner or air tube, either before or after
its manufacture, preferably before the ends of the tube are closed or joined, a
suitable quantity of a flaky substance, such for instance as bran, so that, when
a suitable quantity of water or other liquid is forced into the tube by means of a
pump or otherwise, the said substance will become mixed with and held in suspension
in such liquid and will then be in a condition to fill or close the pores or punctures in
the tube. It may be advantageous to also introduce size or other glutinous substance
with the water or other liquid and bran or the like.
To prevent access of the said substance to the valve for the admission of the air, I
sometimes make the short pipe which is secured in the air-tube and to which the said
valve is secured, with a tubular projection or nozzle extending into the said tube and
I fix on the said nozzle a short piece of flexible tubing of such length that will extend
to the centre or near the centre of the air-space in the said tube. This piece of tubing
being flexible will not be liable to injure the air-tube should the latter be pressed
down upon it.
In making a pneumatic tyre, I sometimes employ a sheath or cover which is made
in the form of an endless tube and into which I introduce, through a slit formed for
the purpose,
suitable length of india-rubber tubing to form the inner tube. I then
draw the two ends of this length of tubing a convenient distance out of the said
sheath and unite them in such a manner as to form an endless inner air-tube. The
aforesaid slit is then closed by lacing or in any other convenient manner.
I sometimes treat the interior surface of the inner tube, either before or after such

page_text: tube is made, with a suitable substance which will fill or close the pores of the india-
rubber and thus ensure the retention of the pressure in the tube with or without the
aid of the bran or the like.
Dated the 22nd day of February 1806
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C..
Agents for the Applicant.
mprovemen
and relating
Pneumatic Tyres Ior wheels.
I, ALFRED HENRY CROCKFORD, of 26 Overy Street, Dartford, in the County
of Kent, 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 :-
My invention relates to pneumatic-tyres for the wheels of bicycles, tricycles and
other vehicles, and its chief object is to ensure more effectually than heretofore the
retention of the air under pressure in such tyres or in the inner or air-tubes
thereof.
It is well known that, when such tyres are inflated, the internal air-pressure
diminishes more or less rapidly either by reason of the porosity of the india-
rubber of which the tube is inade and the consequent gradual escape of the air
through the same, or by reason of the slow leakage of air through small or fine
punctures formed therein, the existence and location of which are not easily
ascertainable or determinable, or by reason of leakage at or around the valve.
Moreover the tyre is liable to be punctured by contact with sharp objects on the
road in such a manner that it will collapse and must be repaired before it can
be again inflated.
By my invention I overcome these difficulties and provide a pneumatic tyre
which will retain the air therein at the desired pressure for a much longer period
than those as heretofore made, and this notwithstanding the formation in such tyre
of any small punctures or even of such punctures as would render the tyres as
hitherto employed useless until repaired.
Attempts have heretofore been made to attain this end by introducing materials
of certain kinds into pneumatic tyres with the object of sealing or closing any
punctures that may be made therein; but so far as I am aware no material has yet
been proposed which will satisfactorily accomplish the desired result.
Now I have discovered that bran, when mixed with water or other suitable
liquid, is well adapted for the purpose of my invention, as it is flaky, light and
absorbent, will not dissolve in the water, and contains a small proportion of gluten
or adhesive matter which causes the pieces to adhere to some extent to each other
and to the interior surface of the air-chamber of the tyre, without preventing their
being carried around with the water. Moreover the water serves to moisten the bran
and thus improve its action in closing or stopping up the pores or punctures, and
also, while the wheel is in motion, to carry or sweep the bran around the interior of
the said tube and thus ensure the efficient distribution thereof, under the action of
the centrifugal force, over the inner surface of the tread-portion of the tyre.
According to my said invention, therefore, I introduce into the air-chamber of the
tyre, either before or after its manufacture, a suitable quantity of bran or similar
light, absorbent, flaky and slightly adhesive substance, and 1 force into the tyre,
by means of a pump or otherwise, a suitable quantity of water or other liquid so
that the bran or similar substance will become mixed with and held in suspension in

page_text: such liquid, and will then be in a condition to fill or close the pores or punctures
in the tube. I sometimes introduce the bran or like material into the air-tube
before the ends thereof are joined; in other cases, for example, in applying my
invention to existing tyres, I cut the air-tube and introduce into the same the bran
or like material and then repair the said tube. I may, if desired, introduce into
the air-chamber of the tyre, size or other glutinous substance with the water
or other liquid and the bran or the like; but I do not consider this necessary.
I find it advantageous to introduce into the air-chamber of a bicycle-tyre, for
example, about one-half pint to one pint of bran, and a quantity of water or other
suitable liquid sufficient to prevent the accumulation of the bran at any one part of
the tube while the wheel is in motion. I find that, with the quantity of bran above
stated, about half-a-pint of water is enough for the purpose. I can, however, employ
a larger or smaller proportion of liquid if desired; and I can also, if desired, use a
greater or less quantity than that above mentioned of the bran or like substance.
The quantities of bran and water must, of course, be varied according to the size of
the tyre. The moistened bran completely closes any fine apertures or passages that
may exist in the tyre when made, and also serves to automatically close punctures such as
are frequently caused in use, and accomplishes this result so rapidly and effectively as
not to permit the accidental deflation of the tyre.
To prevent access of the bran or other flaky substance to the inner end of the
valve-tube or air-inlet-pipe, I sometimes make the short pipe which is secured in the
air-tube and to which the said valve is secured, with a tubular projection or nozzle
extending into the said inbe, and I fix on such extension or nozzle a short piece of
flexible tubing of such length that it will extend to the centre or near the centre of
the air-space in the said tube. This piece of tubing being flexible will not be liable
to injure the air-tabe should the latter be pressed down upon it, and whilst it will
permit the ingress or egress of air when the valve is opened, it will prevent the bran
or like substance from getting to the valve.
In making a pneumatic tyre, I sometimes employ a sheath or cover which is made
in the form of an endless tube, and I introduce into such sheath or cover, through a
slit formed therein for the purpose, a suitable length of india-rubber tubing to form
the inner tube. I then draw the two ends of this length of tubing a convenient distance
out of the said sheath through the said slit, and unite the said ends in such a
manner as to form an endless inner air-tube. The aforesaid slit is then closed by
lacing or in any other convenient manner. I thus produce a tyre having an outer
cover or sheath and an air-tube enclosed therein, both of which are endless, so that
no part of the tyre is unduly beavy, as is the case in tyres wherein the iuner tube is
closed at its ends and such ends overlap each other. To render such a tyre
self-closing, I introduce the bran or like substance into the air-tube before joining its
ends, and 1 afterwards force the water or other liquid into the said tube through the
air-inlet-valve.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I desire it to be understood
that I am aware that it has been heretofore proposed to insert in the air-chamber
of a tyre small pieces of oiled silk, rubber-coated fabric, sheet india-rubber and
like materials for the purpose of making the tyre self-closing, but such materials
differ very greatly in character from bran and will not fulfil the same functions as
the bran. It has also been proposed to introduce into the tyre with such small
pieces of oiled silk or like materials, some lubricating substance, such for instance
as glycerine and water, to coat the interior surface of the air-chamber, but not, as
the water is used in my improved tyre, to moisten the enclosed material and sweep
it around the air-chamber so as to properly distribute it throughout the interior
thereof. I am also aware that it has been heretofore proposed to stuff a tyre with
bran to deaden the noise arising from a special construction of rim or felloe. But
I am not aware that it has ever been proposed, prior to the date of my invention,
to introduce into the air-chamber of a tyre bran mixed with a liquid such as water

page_text: in such quantities or proportions that, when the wheel is rotated, the bran will he
carried around and distributed by the liquid, so that a puncture occurring at any
point in the circumference of the tyre will be closed by the bran. Moreover bran has
certain inherent qualities or properties which peculiarly adapt it, when properly
moistened with water, for the purpose of stopping or closing punctures in pneumatic
tyres. And I declare that what I claim is :-
First. The herein described method of providing for the automatic closing of
punctures in a pneumatic tyre by the introduction into the air-chamber of such tyre
of bran or similar light, absorbent, flaky substance and water or other suitable liquid
in or about in the above-named proportions.
Second. The combination, with the air-tube of a pneumatic tyre, of a mixture of
bran with a liquid such as water contained in the said air-tube, the bran and liquid
being mixed in such proportions that the bran, in addition to being moistened, will
be swept around the tube by the liquid and thereby distributed throughout the said
tube while the wheel is in motion, substantially as, and for the purpose, hereinbefore
described.
Third. An inflatable or air tube for a pneumatic tyre, in which there is attached
to the inner end of the valve-tube or air-inlet-pipe a piece of flexible tubing of such
length that it will extend to the centre or near the centre of the air-space when the
tyre is inflated, as, and for the purpose, above specified.
Fourth. A pneumatic tyre comprising an endless tubular cover or sheath and an
endless inner or air tube enclosed therein, substantially as, and for the purposes, above
specified.
Dated this 23rd day of November 1896
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicant.