Improvements in the Construction of Pneumatio Tyres.
Year: 1891

page_text: Date of Application, 21st Sept., 1891
Complete Specification Left, 10th May, 1892-Accepted, 31st Aug., 1892
.
PROVISIONAL SPECIFICATION.
Improvements in the Construction of Pneumatio Tyres.
I THOMAS DUNN of 83 Tierney Road Brixton Hill in the County of Surrey
Member of the Stock Exchange do hereby declare the nature of this invention to
be as follows:-
In my former Patent of 22nd August last No. 14173 I describe a device for
protecting a pneumatic tyre fron puncture without impairing its ease of running
but rather increasing it which consists of a steel band rendered perfectly flexible
when buried in the materials of the tyre by being divided into short segments and
covered with a 'plano-convex strip of rubber to retain the circular form of the
tyre, & form a good running surface. These short steel segments required in
practice to be riveted together on a strip of some flexible material such as
canvas, or by some other means involving labour & greatly adding to the cost
of the tyre, to be joined together into a continuous band. I now propose instead
of this to make the band of much thinner steel than before, whereby I secure great
saving in weight, &, to secure rigidity in its breadth & increased flexibility in its
length, whether free or when buried in the materials of the tyre, by corrugating it
from side to side throughout its length. Such a thin corrugated steel band would
I think be found to be as flexible as could be, whether free or when buried in the
materials of the tyre, the corrugations admitting of the band readily undergoing
slight contraction in its length; but, if it should be found that its flexibility
would in practice be increased by dividing it into short segments, it might be so
divided, & these short pieces would not as before require to be riveted to a strip of
canvas, or otherwise fastened together to constitute a continuous band, but would
be sufficiently secured in their positions when buried in the materials of the tyre,
by being simply made to overlap one another at the ends to the extent of one
corrugation, as the corrugations would then retain them in position.
Finally still further to simplify the construction of tyres on this principle, I propose
that this corrugated steel band should be made up by the rubber manufacturers
with the plano-convex strip of rubber, instead of their being produced separately,
&, to avoid the corrugated steel band wearing the surface of the air tube in contact
with it, the corrugations on the outerside of the band should be filled up with
rubber:-that in fact the steel band should be entirely buried just under the surface
of the flat side of the plano-convex strip of rubber. Should the band still be made
of short plain uncorrugated plates, I propose that it should likewise be made up by
the rubber manufacturer together with the rubber strip, & I would insure secure
adhesion between the short plates & the rubber strip by having small turned up
ears formed on their sides or ends, or small loops stamped in them, which ears or
loops should project into the body of the rubber band, or by some other similar
simple device.
Another plan I have devised to increase the rigidity of the steel band in its
breadth & simplify its manufacture is to fold over the ends of the short segments
whether plane or corrugated so that they would hook on to one another & so form
a chain of themselves which would require no other fastening.
Dated this 21st day of September 1891.

page_text: COMPLETE SPECIFICATION.
Improvements in the Construction of Pneumatic Tyres.
I, THOMAS DUNN, of 83 Tierney Road, Brixton Hill, in the County of Surrey,
Member of the Stock Exchange, 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:-
In the Specification of another application for Letters Patent filed by me,
dated 22nd August 1891, and numbered 14173, there is described a construction of
pneumatic tyre wherein the air tube is protected against puncture, without impairing
its ease of running, but on the contrary increasing it, by providing the tyre with a
thin flat protecting band of hard material, for example steel, rendered perfectly
flexible and elastic in its length when buried in the materials of the tyre, by being
divided into a number of short pieces; and great resiliency and ease of running of
the tyre is obtained by covering the protecting band with a strip of flexible
material such as india rubber, of plano-convex form in cross section; which,
together with the band, is placed between the air tube and the canvas tube or other
tough covering commonly employed to prevent undue expansion of the air tube,
so that the rubber strip is constantly subjected to the pressure of the compressed
air, and a narrow running surface is produced, of constant breadth independent of
the degree of the compression of the air in the air tube.
Now my present invention has reference to further improvements in pneumatic
tyres of the kind referred to, whereby the cost of construction and weight of such
tyres are considerably reduced.
For this purpose I make the protecting band of from say about one half to
one third of the former thickness, thus effecting great saving in weight, and, to
secure rigidity in its breadth and increased flexibility in its length, whether free
or embedded in the materials of the tyre, I corrugate it in a transverse direction
throughout its length. Such a thin transversely corrugated steel band is very
flexible, and the corrugations admit of the band readily undergoing slight contrac-
tion and expansion in its length. It may be made in one length, or in a number of
short pieces. When made in a number of short picces, these can be securely held
in position, when enclosed in the materials of the tyre, by being simply made to
overlap one another at the ends to the extent of one corrugation; or they may be
otherwise suitably connected. To still further simplify the construction of such
tyres, the corrugated steel band may be combined with the plano-convex strip of
india rubber in such a manner that the two can be applied to or removed from the
air tube as one piece instead of separately. To avoid the corrugated steel band
wearing the surface of the air tube in contact with it, the corrugated band may
advantageously be entirely embedded in the plano-convex strip of rubber, so as to
be just under the flat side of this strip.
In the accompanying drawings
Fig. 1 is a cross section of a pneumatic tyre constructed with a corrugated
protecting band according to my present invention; and
Fig. 2 is a central vertical section of a portion of such a tyre on the line x x
Fig. 1.
1 is the air tube of the pneumatic tyre; and 2 is a thin transversely corrugated
band of metal that may advantageously be steel of say about No. 50 Birmingham
wire gauge arranged around the air tube. 3 is a strip of elastic material, for
example india rubber wrapped circumferentially around the outer periphery of the
protecting band and having its ends in contact with each other. 4 is the layer of
tough material for example prepared canvas such as is ordinarily employed to
prevent undue expansion of the air tube, and between which and the air tube,
the corrugated metal band 2 and elastic strip 3 are confined so that the
said strip is subjected to the air pressure within the air tube as and for the
purposes fully set forth in my said prior Specification. The tyre is finally

page_text: covered with a layer or coating of india rubber to render it waterproof and
protect it from wear in the usual way and may be secured in the wheel rim 4* in
any known or suitable manner as well understood.
Figs. 3 and 4 are similar views to Figs. 1 and 2 respectively, illustrating a
construction of pneumatic tyre wherein the corrugated metal band is moulded
within and so as to be near the flat inner surface of the india rubber strip.
In each arrangement I find it advantageous to bevel the sides of the corrugated
band as shown at 2* so that these sides are approximately parallel and near to the
outer adjacent sides of the plano-convex strip in which the band becomes or is
embedded. I also find it advantageous not to remove the burr produced on the
edges of the band by bevelling it, as such burr assists in effecting an intimate
connection between the band and the said rubber strip.
For tyres for cycles I have found it advantageous to make the corrugation
of about of an inch pitch and of an inch in depth. In larger and stronger
tyres for other vehicles the thickness of the band and the size of the corruga-
tions would be increased. The corrugations may be either of circular form as
shown, or of approximately rectangular that is crenulated form.
As will be obvious the ends of the corrugated metal band, or of the separate
lengths of which it may be made, can be connected together in various ways.
Thus the ends may be overlapped to the extent of say one corrugation as shewn
in side elevation in Fig. 5; or the ends of the band or of the separate lengths
in which it is made, may be bent over so that one may be hooked on to another as
shewn in side elevation in Fig. 6. When the band is made up of a number of
short pieces and embedded in the strip 3, it is not necessary that the ends of such
short lengths should be securely connected together, if only they overlap each other
to the extent of say one corrugation, as the corrugation would sufficiently hold
them together.
A flexible protecting band composed of a number of pieces of hard material such
for example as steel, that are practically straight or flat in cross section as described
in my said former Specification may also according to this invention be combined
with the india rubber strip for the purpose of simplifying their construction and
facilitating their application to the exterior of the air tube. For this purpose the
plates 5 forming such a flexible band and which may advantageously be arranged
to overlap each other as shewn, may be secured to the flat side of the plano-convex
ring by forming each of them at the sides or ends with small turned over narrow
ears 5 as shewn in cross section and plan respectively in Figs. 7 and 8, these ears
being inserted or moulded in the india rubber strip 3 when the same is in a soft or
plastic state. Or the plates may be secured to the flat side of the strip by loops 5°
which are struck up from the plates and are caused to project into and engage with
the india rubber strip when the same is in a plastic state, as shewn in Fig. 9. Or
the plates may be wholly embedded or moulded within the strip as shewn in Fig. 10.
Or the flat plates instead of being combined with the india rubber strip in the
manner hereinbefore described, or instead of being secured to a strip of flexible
material such as canvas, as described in my said former Specification, may according
to this invention be each bent at the ends so that they can be hooked together as
shewn in Fig. 11 and thus of themselves form a continuous band.
Or this construction can be modified as shewn in Fig. 12 according to which
the projecting band is composed of a number of metal strips 5 of approxi-
mately rectangular form in cross section arranged to overlap each other as
shewn and placed transverse of the india rubber strip 3 wherein they are
embedded. The band thus constructed forms in effect, a transversely corrugated
protecting band.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
:-
1. A pneumatic tyre of the kind herein referred to in which the metallic

page_text: protecting band arranged to surround the air tube within the outer covering is
transversely corrugated as and for the purpose set forth.
2. A pneumatic tyre of the kind herein referred to in which a strip of flexible
material such as india rubber of plano-convex form in cross section has embedded
or moulded therein a corrugated protecting band made in one or more lengths of
transversely corrugated sheet metal substantially as hereinbefore described for the
purpose specified.
3. My improved pueumatic tyres constructed with a transversely corrugated
sheet metal protecting band and flexible strip substantially as hereinbefore
described with reference respectively to and shewn in Figs. 1 and 2, and in
Figs. 3 and 4, of the drawings annexed, whether the said protecting band be made
in one piece or in a number of short pieces, and whether the ends thereof be
connected together or not.
4. A pneumatic tyre of the kind herein referred to in which the pieces of
material of flat or straight form in cross section constituting the protecting band
are either secured to or embedded within the flexible strip in such a manner as to
form a combined flexible ring and protecting band, as hereinbefore described
with reference to the several examples illustrated in Figs. 7 to 10 inclusive of the
drawings annexed.
5. In a pneumatic tyre of the kind herein referred to, a protecting band com-
posed of a number of pieces of material such as steel that are straight or flat in
cross section and are bent at the ends so that they can be hooked together substan-
tially as herein before described with reference to and shewn in Fig. 11 of the
drawings annexed, or modified according to Fig. 12.
- 1000
THOMAS DUNN.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C., Applicant's Agent.