Improvements in or relating to Pneumatic Wheel Tyres.
Year: 1895

page_text: Date of Application, 31st July, 1895
Complete Specification Left, 14th Mar., 1896-Accepted, 2nd May, 1898
PROVISIONAL SPECIFICATION.
Improvements in or relating to Pneumatic Wheel Tyres.
WC, WILLIAM BOWDEN of Barlow Range, Chorlton-cum-Hardy, in the County
of Lancaster, Secretary, and EDWARD HENRY SEDDON of Warwick House,
Ashton-on-Mersey, in the County of Chester, Gentleman, do hereby declare the
nature of this invention to be as follows:-
This invention relates to pneumatic elastic wheel tyres for road vehicles chiefly,
and consists in improvements in the manufacture or method of making the air-tubes
or air-tight linings of such tyres self-healing or self-closing after being punctured,
the object of the invention being chiefly the production of a
and lighter puncture closing air-tube or lining than has hitherto been made.
more effective
The principle upon which the self-healing or self-closing of a puncture in an
elastic tube wall or lining relies is based upon the abnormal elastic compression of
the material produced in the process of manufacture of the air-tube or lining and
from the ordinary elastic material in its normal state. The compression of the
material is at present generally obtained by turning an elastic tube inside out and
so forcing the external surface of the large diameter to assume the internal surface
of the small diameter; by this means though the outer surface may be somewhat
in extension, yet the inner surface is in compression, and the force of compression
acts transversely in the tube.
Our improvements are contained in the process or processes or methods of
manufacture by which we obtain a compression of the material of the tube or
lining, in a longitudinal and peripheral direction, when the air-tube or air-tight
lining is completely formed, and by this means we may obtain a greater elastic
compression of the material than is obtained by other processes of manufacture.
In carrying out our invention we may form the air-tube or lining from a single
length of elastic material, which may first be formed into a tube upon a mandrel
and thickened in one part for the full length. A strip of suitable fabric is then
solutioned over the thickened part, and the tube removed from the mandrel. After
inserting a chalked tape into the tube to prevent the walls thereof from adhering
together it is flattened and rolled up, or rolled upon a thin mandrel with the fabric-
faced side to the mandrel and vulcanised in that position, means being adopted to
prevent the coils from adhering together. After being vulcanised it is unrolled
and the ends brought together and joined to form an air-tight tube; or the ends
may be made up separately and butted together.
In some cases a strip to form the thickened tread portion is faced with fabric on
one side, rolled up and vulcanised in a similar manner to that hereinbefore described.
It is afterwards unrolled, and solutioned or cemented to the air-tube or air tight
lining.
The complete tube or the strip may be made up of several shorter lengths joined
together.
The thickened portion of the tube or lining is in the completed tube or tyre so
disposed as to be on the tread side of the tyre.
The mandrel upon which the tube or strip may be wound may be cylindrical, or
may be convex in its longitudinal direction.
A tube or lining constructed according to this invention has, when straightened,
the material at its surface underneath the fabric facing, in compression. Upon
Price 8a1

page_text: bending the tube into a ring it is still further compressed. By this means, a
puncture made with a sharp instrument instantly closes upon the withdrawal of the
instrument.
Dated this 30th day of July 1895.
R. J. URQUHART,
57, Barton Arcade, Manchester, and 5, Clayton Square, Liverpool,
Consulting Engineer and Patent Agent.
Improvements in or relating to Pneumatic Wheel Tyres.
We, WILLIAM BOWDEN of Merlewood, Sale, in the County of Chester, late of
Barlow Range, Chorlton-cum-Hardy in the County of Lancaster, Secretary, and
EDWARD HENRY SEDDON of Warwick House, Ashton-on-Mersey, in the County
of Chester, Gentleman, 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 :-
This invention relates to pneumatic elastic wheel tyres, and air tubes therefor,
and consists in improvements in the manufacture or method of making the air tube
or air tight linings self-healing or self-closing so that they shall have the property
of closing up immediately, punctures or piercings accidentally received and so
prevent the escape of the fluid contained therein under pressure, the object of this
invention being the production of a more effective and more easily manufactured
air tube or air tight lining having such puncture-closing property than has hitherto
been made.
This property by which punctures are closed up sufficiently to prevent an
appreciable reduction of pressure in an air tube constructed accordingly, relies
upon compression of the elastic indiarubber wall of the air tube or airtight lining
of the tyre, which is produced and retained by several methods, but generally
by turning an indiarubber tube of suitable thickness inside out, so that the
outer surface forced to assume the inner surface of less diameter is somewhat
compressed.
Our improvements are contained in the process or methods of manufacture by
which we obtain longitudinal compression and apply it in or to the pneumatic tube
or lining in such a manner that the tyre will be protected in the direction in which
it is most likely to receive a puncture.
In accordance with this invention we form a strip or band of unvulcanised or
partly vulcanised indiarubber of sufficient width to cover as much of the pneumatic
tube in a transverse direction as it is desired to protect in this way, and of length
sufficient to encircle the pneumatic tube longitudinally. We cement a strip of
inextensible fabric upon one side of this india rubber strip or band and we then roll
or wind this compound indiarubber and fabric strip upon a thin mandrel in a
helical manner and cure or vulcanise the strip in this position. After thus forming
and treating the compound strip it is removed from the mandrel and assumes a
helical coil in its normal state. We then secure the band when straightened out to
the pneumatic tube or lining by indiarubber solution or cement in such a manner
that the fabric face of the strip lies outwardly with relation to the compressed
indiarubber.
By an alternative method the indiarubber strip may be wound singly upon the
mandrel and vulcanised, the canvas or fabric being afterwards applied.
The outer indiarubber surface of the compound band is when the band is in its
normal state, or when wound upon the mandrel, obviously longer than the surface
which lies against the fabric, as the first mentioned surface is farther away from
the centre of the mandrel than the fabric faced surface. Consequently when the

page_text: compound band is removed from the mandrel and straightened out, the substance
at the outer india rubber surface is compressed longitudinally and when the
compound band is curved round to encircle the pneumatic tube it is still further
compressed.
The drawings attached hereunto illustrate the method of forming and compressing
the compound strip and indicate the manner of application to the pneumatic tube
or tyre.
In the drawings
Figure 1 represents a part of a mandrel having a portion of the compound band
wound thereon.
Figure 2 represents, diagrammatically, an end view of the mandrel with a coil
of the compound band on the mandrel after vulcanisation and a portion of the
band unwound and the curvature reversed, indicating by the dotted radial lines the
direction and extent of the compression obtained.
•
Figure 3 represents a cross sectional view of the pneumatic tube with the
compound band attached thereto upon the exterior surface of the pneumatic
tube, and
Figure 4 also a cross sectional view of the pneumatic tube having the compound
band attached to the interior surface of the said tube.
non-
In the several views like parts are indicated by like letters of reference.
Referring first to Figure 1 which represents the compound strip or band a wound
helically upon the mandrel b. The compound band a is produced from a strip a
of unvulcanised or uncured or partly cured india-rubber, to one face of which is
cemented a covering of inextensible fabric a. The band may be of any required
width but it is generally preferred of sufficient width to cover the part of the
pneumatic tube on the tread side, and for illustration is shewn about one inch in width.
The compound band is wound helically upon a mandrel b which is of lesser diameter
than the pneumatic tube and as small as can conveniently be used, with the fabric
covered side of the band to the mandrel. After securing the ends of the bands to
the mandrel and wrapping the outer face of the coiled band round with a
adhesive covering or otherwise protecting it, in the usual way, it is vulcanised or
completely cured, and then removed from the mandrel. In its coiled state the
india rubber is not in compression but upon straightening out the coils the outer or
elastic surface a³ of the coils which is longer than the surface secured to the fabric,
and which cannot stretch on account of the fabric being inextensible, is compressed
in assuming the length determined by the fabric, and when the curvature of the
band is reversed the surface a³ is still further shortened or compressed. This is
illustrated in Fig. 2 which represents an eud view of the mandrel having a coil of
the band a thereon and a continuation a' from the coil, of the band having the
curvature reversed. The spaces x, x, between the radial lines are on the outer
surface as of the coils more extensive than the spaces between the same radial lines
on the surface a when the band after vulcanisation is in its normal state. When
however the curvature is reversed as indicated at a the spaces all on the
surface a³ of the band are seen to be less extensive than those on the surface aª
which remain constant.
In some
cases the elastic strip a¹ may be vulcanised before applying the
inextensible fabric facing a³. It is then removed from the mandrel and the fabric
strip a wound thereon, the outer surface of the strip a' being solutioned or made
adhesive. The elastic strip a' is then rewound upon the mandrel b over
the adhesive fabric strip a2, and bound to the mandrel until the cement is set.
After the band a has been produced in the manner hereinbefore described it is
attached by means of indiarubber in solution or cement to the pneumatic tube or
air tight lining.
Figure 3 illustrates the pneumatic tube or air tight lining eas having the
compressed compound band a secured to the exterior surface. Figure 4 illustrates
the pneumatic tube or lining c as having the band a secured to the interior surface.
The exterior dotted lines in the Figures 3 and 4 indicate the protective jacket

page_text: or tread of the tyre and wheel rim, which may be of the usual construction and
form.
The compressed compound band a may be of any desired width so that it may
encircle the pneumatic tube transversely or only partly do so. When it is required
to be of sufficient width in order to encircle the pneumatic tube it may be made up
of two strips secured together at their edges.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :
First. The manufacture of self sealing pneumatic tubes or of self sealing air
tight linings of pneumatic tyres substantially as described herein before and as
illustrated in the drawings.
Second. The method of producing compression in a band of elastic india rubber
and fabric and of applying a band so compressed to a pneumatic tube or air tight
lining of a pneumatic tyre substantially as and for the purpose herein described
and as illustrated in the drawings.
Third. The method of forming a compound band of elastic india rubber and
inextensible fabric so that it assumes in its normal state the form of a helical coil,
and of applying a band so formed to a pneumatic tube or air tight lining of a tyre
with the inextensible fabric lying on the outer side of the said band substantially as
described and illustrated and for the purpose set forth.
Fourth. The combination with a pneumatic tyre or tube of a band formed and
applied in the manner hereinbefore described and illustrated and for the purpose
set forth.
1
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1 1000
R. J. URQUHART,
57, Barton Arcade, Manchester, and 5, Clayton Square, Liverpool,
Consulting Engineer and Patent Agent.