Improvements in Pneumatic Tyres for Wheels.
Year: 1893

page_text: Date of Application, 20th June, 1893
Complete Specification Left, 20th Mar., 1894-Accepted, 21st Apr., 1894
PROVISIONAL SPECIFICATION.
Improvements in Pneumatic Tyres for Wheels.
I, GEORGE ANDREW MACBETH of 41 Conyers Road Streatham Surrey S. W.
Engineer do hereby declare the nature of this invention to be as follows:-
My invention refers to a form of pneumatic tyre wherein the inflated part of the
tyre is divided into a number of sections so arranged and operating that in the
event of one or more of the said sections becoming punctured or damaged the injury
is localised to the said section or sections and the wheel to which the tyre is
attached is not rendered inoperative, the said sections are of cylindrical spherical
or other form suitable for enclosure within an outer tyre cover or casing and are
provided with an orifice or projection capable of engaging with a corresponding
projection or orifice formed on or in an endless tube the purpose and use of which
will be presently explained.
Within the said endless tube I insert a second endless tube formed of india
rubber or other elastic material, the outer tube (which may be of india rubber or
other suitable material) is provided with an air valve and means of coupling on to
an air pump.
The inner tube is provided with a like valve and coupling which passes through
the outer tube and is securely jointed to same so that the two tubes are capable of
being independently inflated.
The number of orifices or projections in or on the outer tube correspond with the
number of sections above referred to.
The projections are of button like form with central holes or passages for
communicating with the tubes or sections to which they are applied.
When a projection is on the section a corresponding orifice is formed in the tube
and acts as a button hole so that the section can be attached to the tube.
In operation my invention is as follows:-
The endless outer tube and its internal tube are placed on the rim of the
wheel, the two air valves and couplings passing through suitable openings in
the rim.
The aforementioned sections are then buttoned on to the outer tube until the
vhole periphery of the wheel is surrounded.
In some cases the whole or part of the sections may be buttoned on before
lacing the tube on the rim.
When the sections are so attached the tyre cover is placed in position and air
s forced by an ordinary pump through the valve connected with the outer endless
ube.
By this means the whole of the sections and the outer tube becomes inflated
hilst the pressure causes the projection to be tightly pressed against the sides or
ther parts of the orifices so that they become air tight. When this has been
ccomplished the pump is caused to operate through the valve communicating with
he internal tube until it has been inflated sufficiently to expand to the inner
urface of the outer tube thereby covering the orifices in the latter and enabling
ny of the sections to be punctured or damaged without losing the
ontained in the other sections
pressure

page_text: It will thus be seen that in the event of puncture or other injury of any of the
sections the wheel will not be totally disabled but can be used until such time as a
spare section can be conveniently replaced.
Dated this Twentieth of June 1893.
GEORGE ANDREW MACBETH,
Streatham, S. W.
CITICATION.
Improvements in Pneumatic Tyres for Wheels.
I, GEORGE ANDREW MACBETH, of 101, Foxbourne Road, Upper Tooting, in
the County of Surrey, 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 refers to a form of pneumatic tyre wherein the inflated part of the
tyre is divided into a number of sections so arranged and operating that in the
event of one or more of the said sections becoming punctured or damaged the injury
is localised to the said section or sections and the wheel to which that tyre is
attached is not rendered inoperative.
I will fully describe my invention in reference to the accompanying drawings in
which similar letters of reference refer to similar or analogous parts.
Fig. 1 is a longitudinal section of part of a tyre illustrating my improvements,
and Fig. 2 is a cross section thereof.
Figs. 3 and 4 are similar views of a modified arrangement hereinafter described.
The sections S are made of india-rubber or other inflatable material, and may be
of cylindrical, spherical, or other form suitable for enclosure within any suitable
outer tyre-cover or protective casing such as T, or in some cases they may be used
without such protective cover.
According to the arrangement shown in Figs. 1 and 2, each section S is provided
with an orifice a made through a projection a so as to be capable of engaging with
or attachment to a corresponding orifice formed in or on an endless inflatable tube
such as O. This tube is made of such material or materials as to render it of
sufficient strength to withstand the air pressure. Or, as in Figs. 3 and 4 the
orifices may be simple holes through the material of the tube as hereafter explained.
In all cases, within the said tube O for the purpose of simultaneously sealing or
unsealing when required all these said orifices a of the outer tube OI insert an
inner tube I. Each tube O and I is provided with the usual means of inflating
and deflating as shown respectively at C° and C, and has the usual means of
coupling on to an air pump. The inflating device C₁ of the inner tube I may pass
through the outer tube O or be arranged at the end of same or otherwise suitably,
and it as well as the device C" of the outer tube O may pass through the rim of
the wheel or be otherwise conveniently arranged in such manner that the two
tubes O and I are capable of independent inflation.
Instead of attaching the sections S outside the tube O as above specified it is
obvious that the tube O containing the tube I may be arranged within and passing
through the sections S. Such an arrangement is illustrated in Figs. 3 and 4. The
sections S may be manufactured independently and attached to each other by
solution or otherwise, or left separated one from the other but securely attached to
the outer tube O at the points p p. p.; or the sections may be formed by the
placing of partitions in a tube or other suitable lengthened receptacle, or in any
other convenient manner. The orifices a. a. in the tube O open into each section S,
the inner inflatable tube I is arranged within the outer one O as before and both
are provided with independent inflating and deflating devices as shown.
In operation the deflated pneumatic tyre constructed as above described and the
outer cover T (if used) is or are placed upon the rim of the wheel, the sections

page_text: being buttoned or screwed on to the tube O as in Figs. and 2, or connected'
together as in Figs. 3 and 4, and would then appear as shown at S* S*. Air is
then forced by an ordinary pump through C° into the outer tube O, from which it
passes through the orifices a. a. into the sections S. S. until the whole of the
sections become sufficiently inflated. When this is effected the air pump is applied
to C¹ and the inner tube I is inflated sufficiently to expand the whole of its outer
surface firmly against the inner surface of the outer tube 0 (as shown to the right
of Figs. 1 and and in the sections 2 and 4) thereby covering and completely
sealing all the orifices a. a. in the latter.
By this means any of the sections S may be punctured or damaged without
losing the pressure contained in the other sections, and therefore the wheel will not
be totally disabled and can be used until such time as a spare section can be
conveniently replaced. To deflate the tyre it is only necessary to first liberate the
valve in the ordinary way of the inner tube I and then that of the outer tube O.
I desire to state that I lay no claim to sectional pneumatic tyres generally, but
having now particularly described and ascertained the nature of this invention and
in what manner the same is to be performed, I declare that what I claim is :-
In a sectional pneumatic tyre for wheels, the means of sealing and unsealing the
inflated sections which consists in the use of two tubes O and I one arranged within
the other, the outer one being in pneumatic connection with each section and the
inner one adapted to seal and unseal the said pneumatic connections as and when
required, substantially in the manner above set forth.
Dated this 20th day of March 1894
Dated this 20th day of March 1894
For the Applicant,
J. C. CHAPMAN,
70, Chancery Lane, London, W.C., Chartered Patent Agent..