An Improved Pneumatic Tyre.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
An Improved Pneumatic Tyre.
1, OTTO HELLSTERN, of 47, Darrell Road, East Dulwich, in the County of
London, Electrician, do hereby declare the nature of this invention to be as
follows:
My invention has for its object a pneumatic tyre for velocipedes and other
vehicles which shall be inflated by means of its coming in contact with the ground
during the rotation of the wheel to which it is attached, and the often laborious
process of pumping the tyre now generally in vogue, obviated.
Describing my invention in connection with a pneumatic tyre of the well
known Dunlop" type, I fix within the inner tube of such tyre a series of hollow
balls or their equivalent of rubber or like material or substance. These balls
or the like are of larger diameter than that of the tube in which they are fixed
and, with the exception of the first and last of the series, each ball or the like
is connected with the ball next it on either side by a connecting tube. The said
inner tube of the tyre is thus divided up into a number of compartiments which
I cause to communicate with one another by means of circumferential channels,
passages or openings situated at the points of attachment between the inner sur-
face of the inner tube and the outer surface of each of the said balls or the like.
The first ball of the series is connected to the ball next it, on one side by means
of a tube as already described, but the other side of this ball communicates with
a suitable in-take valve passing through the rim of the wheel, or otherwise con-
veniently situated. This in-take valve is a back-pressure valve of any convenient
pattern, so that air can be drawn therethrough into the said first ball, but cannot
pass out again.
The last ball of the series is connected to the ball next it on one side by means
of a tube as already described, but in its other side, or that side facing the first
ball of the series, is an opening fitted with a non-return valve, which communi-
cates with one of the said compartments into which the inner tube is divided.
Each ball of the series is fitted with a non-return valve.
When the tyre is deflated or partially deflated, upon the wheel being revolved
in contact with the ground each of these balls is compressed in turn by the
superposed weight of the machine or vehicle, and as the wheel continues to travel,
each ball again in turn expands (owing to its natural elasticity). Upon this
expansion taking place, in the case of the first ball of the series, air is drawn
into this ball through the said in-take valve and as the wheel revolves, the air
is passed from ball to ball through the connecting tubes until the last ball is
reached, when it passes out into the compartment with which this ball communi-
cates, as already described. The non-return valve with which each ball is fitted
permits air to be thus drawn into the tyre but allows none to pass back again
in the opposite direction. As all the compartments of the inner tube communi-
cate with one another by means of the circumferential passages as already

page_text: described, the whole tyre now becomes suitably inflated. A suitable valve may
be supplied for the purpose of deflating the tyre when necessary.
It is obvious that my invention may be equally well applied to a single tube
pneumatic tyre.
I, OTTO HELLSTERN, of 47, Darrell Road, East Dulwich, in the County of
London, Electrician, 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 has for its object a pneumatic tyre for velocipedes and other
vehicles, which shall be inflated by means of its coming in contact with the ground
during the rotation of the wheel to which it is attached, and the often laborious
process of pumping the tyre now generally in vogue, obviated.
Describing my invention in connection with a pneumatic tyre of the well
known Dunlop" type, I fix within the inner tube of such tyre a series of hollow
balls or their equivalent of rubber or like material or substance. These balls
or the like are of larger diameter than the normal diameter of the tube in which
they are fixed when the latter is deflated and, with the exception of the first and
last of the series, each ball or the like is connected with the ball next it on either
side by a connecting tube. The said inner tube of the tyre is thus divided up
into a number of compartments which I cause to communicate with one another
by means of circumferential channels, passages, or openings, situated at the
points of attachment between the inner surface of the inner tube and the outer
surface of each of the said balls or the like. The number of such balls will be
determined by the consideration that there must not be too great a difference
between the pressure in any two consecutive balls as otherwise a considerable
amount of compression of the tyre would be required to make the device act.
I have found six or seven a convenient number.
The first ball of the series is connected to the ball next it on one side by means
of a tube as already described, but the other side of this ball communicates with
a suitable in-take valve passing through the rim of the wheel, or otherwise con-
veniently situated. This in-take valve is a back-pressure valve of
any convenient
pattern, so that air can be drawn therethrough into the said first ball, but cannot
pass out again.
The last ball of the series is connected to the ball next it on one side by means
of a tube as already described, but in its other side, or that side facing the first
ball of the series, is an opening fitted with a non-return valve, which communi-
cates with one of the said compartments into which the inner tube is divided.
Each ball of the series is fitted with a non-return valve.
When the tyre is deflated or partially deflated, upon the wheel being revolved
in contact with the ground, each of these halls is compressed in turn by the
superposed weight of the machine or vehicle, and as the wheel continues to travel,
each ball again in turn expands (owing to its natural elasticity). Upon this
expansion taking place, in the case of a first ball of the series, air is drawn

page_text: into this ball through the said in-take valve and as the wheel revolves, the air
is passed from ball to ball through the connecting tubes until the last ball is
reached, when it passes out into the compartment with which this ball communi-
cates, as already described. The non-return valve with which each ball is fitted
permits air to be thus drawn into the tyre but allows none to pass back again
in the opposite direction. As all the compartments of the inner tube communi-
cate with one another by means of the circumferential passages as already
described, the whole tyre now becomes suitably inflated.
I will now proceed to further describe my invention in connection with the
accompanying drawings, in which the same letters of reference indicate like parts
in the various figures.
Fig. 1 is a lougitudinal sectional view of the air tube of a pneumatic tyre
fitted with my invention, and,
Fig. 2 is an enlarged longitudinal sectional view of a section of such air tube,
showing the air inlet valve and the first and last ball-shaped chambers of the
series.
To the air tube of the tyre is fitted the air inlet of any suitable form, which
communicates by means of the tube of rubber or the like with the non-return
valve in one end of the first ball-shaped chamber c attached to the inside of the
tube a as shown. The other end of this chamber c communicates by means of a
rubber or like tube with a non-return valve in the one end of the next ball-
shaped chamber of the series c², which latter in turn has its other end communi-
cating by means of a suitable tube with the non-return valve attached to
one end of the next ball-shaped chamber c³. This latter chamber c³ communicates
similarly with the next chamber of the series of, and all the remaining chambers c³,
c, c, communicate with one another in like manner by means of tubes and
non-return valves, until the last chamber c is reached. It will now be seen
that the tube a is, by means of these ball-shaped chambers c, 2, 3, 4, 5, 6, and
c, divided up into a number of compartments or divisions d between which the
air can circulate freely by means of the passages p.
The free end of the last chamber e is fitted with a non-return valve and is
supported by means of a stays of rubber or other suitable substance or material.
All the non-return valves allow air to pass through them in the direction
indicated by the arrows, but no air is capable of returning through these valves.
Fig. 3 is a longitudinal sectional view of a ball-shaped chamber c of suitable
form which has the band or the like formed thereon, or attached thereto, as a
means whereby it may be fixed in a tube such as a (Figs. 1 and 2) and which is
provided with a passage such as for the circulation of air.
Only one passage is shown, but it is obvious that any required number of
these passages may be employed.
The tube is fitted with a valve for deflating the tyre when required.
When the tyre is deflated or partially deflated, as the wheel revolves and that
part of the tyre in which the ball-shaped chamber is situated comes in contact
with the ground, this chamber e will (owing to its elastic nature) be compressed
or partially compressed, by the superposed" weight of the vehicle and its load
and the air or part of the air contained therein will be forced along the tube t¹
and through the valve into the chamber c³. As the wheel continues to revolve
the chamber c will be released and, expanding, will draw in a fresh supply of air
through the in-take 1, tube t, and valve v. The chamber will next be similarly
compressed, and the air or part of the air it contains be similarly passed into the
next ball-shaped chamber of the series; upon being released this chamber c² will
expand and draw in a fresh supply of air through the valve and tube . This
action continues in turn with each ball-shaped chamber of the series as the wheel
revolves, fresh supplies of air being drawn in at the in-take / as often as required.
When the last chamber of the series is in turn compressed, the air or part of the
air contained therein passes out through the valve into one of the compartments
or divisions d and as these latter communicate with one another by means of the

page_text: passages p, the whole of the tube a will become inflated as the wheel continues
to revolve and the action explained above is repeated, until sufficient air has in
this way been drawn into the tyre to properly support the superincumbent weight.
It is obvious that my invention may be equally well applied to either single
or double tube pneumatic tyres, and that the number of ball-shaped chambers
employed may be varied to suit requirements.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
-
(1) A pneumatic tyre for velocipedes or other vehicle wheels having the air
tube thereof fitted with an air inlet such as 7, and a series of compressible chambers
communicating with one another and the said air inlet, by means of a series of
valves and tubes, the last chamber of the said series communicating by means
of a valve with the said air tube, and passages such as being provided to allow
the free circulation of air within the said air tube, operated, substantially as and
for the purpose herein described and illustrated.
(2) In a pneumatic tyre, the air tube of which is divided into a number of
divisions such as d by means of a series of ball-shaped chambers as described
passages such as p substantially as and for the purpose herein described.
Dated this 15th day of December 1897
CASTLE SMITH,
"Invention" Office, Mitre Court, Fleet Street, London, E.C.,
Agent for the Applicant.