Improvements in or relating to Pneumatic Tyres.
Year: 1893

page_text: Date of Application, 18th Dec., 1893
Complete Specification Left, 18th Sept., 1894-Accepted, 20th Oct., 1894
PROVISIONAL SPECIFICATION.
Improvements in or relating to Pneumatic Tyres.
I, CHARLES KINGSTON WELCH, The Hollies, Eaton Road, Coventry, in the
County of Warwick, Engineer, do hereby declare the nature of this invention
to be as follows:-
My invention relates to pneumatic tyres and has for its object to construct for
such tyres an improved tread surface which will withstand wear on the road to a
greater degree than the tyres hitherto manufactured.
According to my invention I provide an arched tread or band of rubber or like
material, which is secured by solution or other suitable means to the outside of the
pneumatic tyre so as to form the wearing surface of the tyre. Said arched tread
or band is however, according to my said invention, manufactured in such a manner
that when in place upon the tyre its outer surface is compressed and is thereby
rendered much less liable to cut or split and wears much longer than the ordinary
surface of such tyres. The mode of placing the rubber tread in compression and
thereby causing it at the same time to grip the tyre very strongly, forms an
important feature of my invention.
In one method of manufacturing my improved bands I proceed as follows, that
is to say, I mould the band with an inner lining of canvas or other suitable
inextensible material upon a mandrel or core of suitable circumference in the usual
manner. The cross-sectional diameter of said mandrel is much less than that of
the tyre to which the band is to be applied when finished. The band is preferably
moulded in the form of a tube which is thin at its smallest or internal circumference
and thicker at its largest or external circumference. After vulcanization
(preferably in a closed metal mould) the tube is cut round its inner circumference
and taken off the mandrel or core. The tube is thus converted into an arch the
curvature of which taken on a transverse section is much greater than that of the
tyre to which it is to be applied. Hence when the arched rubber band is secured
to the tyre the curvature of said band is lessened and owing to its inextensible
lining the outer part thereof is placed in compression. The tread so mounted hugs
the tyre very strongly and does not tend to lift at the edges which is an important
advantage.
The mandrel or core is preferably provided with a groove or nick extending
round its internal circumference so as to guide the knife or other instrument when
cutting round the tube vulcanized thereon.
The canvas or other lining may be placed on the mandrel with its threads
extending circumferentially round the mandrel and I preferably form such lining
from an endless band cut from a woven tube of a diameter approximately equal to
that of the arched tread when finished, I thus make the said tread without a transverse
joint. I sometimes make a joint in the mandrel or core and thread a length of
woven canvas tube thereon, or I sometimes form an inextensible backing to the
rubber bands by winding a suitable thread, cord or the like closely round the
mandrel or core, and secure the rubber or the like thereto by vulcanizing or other-
wise. The aforesaid canvas lining nay if desired be applied to the mandrel
so that the threads thereof extend diagonally or in other suitable directions.
I sometimes mould the band in the form of an arch instead of making a closed
tube and afterwards cutting the same. In all cases however, the curvature of the
arch is greater before the band is applied to the tyre than after it is secured
thereto.

page_text: Furthermore, in some instances I provide inextensible wires or cores in the
edges of my improved band somewhat in the manner described in the prior
Specification of British Letters Patent No. 14563 A.D. 1890 with reference to
solid and cushion tyres.
My improved compressed band or tread may be applied to the outside of a
pneumatic tyre of any description whether such tyre is provided with a separate
air tube or not.
In the former case, that is to say, when the tyre has a separate air-tube, the
compressed rubber band is preferably secured to the outer inextensible jacket or
cover of the tyre, after the latter has been covered with a layer of thin flexible
rubber or like material.
I sometimes line the inextensible backing of the band with a thin layer of rubber
prepared in a manuer most suitable for securing the same by solution or otherwise
to the tyre.
In some cases my improved rubber tread or band may be moulded with corru-
gations or other suitable designs.
My improved band is especially suitable for use with tyres of large cross-section
such as those employed on the wheels of heavy vehicles, but it may obviously be
used with the tyres of velocipede and other light wheels.
Dated this 18th day of December 1902
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Pneumatic Tyres.
1, CHARLES KINGSTON WELCH, The Hollies, Eaton Road, Coventry, in the
County of Warwick, 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, and has for its object to provide for
such tyres an improved tread surface which will withstand wear to a greater degree
than the tyres hitherto manufactured.
According to my invention 1 provide a tread or band of india rubber or like
material arch shaped in transverse section which is secured by solution or other
suitable means to the outside of the pneumatic tyre so as form the wearing surface
of the tyre. The said arched tread or band is however, according to my said
invention, manufactured in such a manner that when in place upon the tyre its
outer surface is compressed and is thereby rendered much less liable to be cut or
split and wears much longer, than the uncompressed surface of pneumatic tyres
heretofore made. The mode of placing the rubber tread in compression and thereby
causing it at the same time to grip the tyre very strongly, forms an important
feature of my invention.
In the accompanying drawings
Figure 1 is a transverse section of one of my improved tread-pieces before the
same is applied to a tyre, the rubber being in its normal state.
Figure 2 is a transverse section of a tyre having one of my improved tread-
pieces applied thereto.
Figure 3 is a cross-section shewing a modified form of tread-piece having
comparatively thin flaps attached to or formed at its edges before said tread-piece
is applied to a tyre.
Figure 4 is a transverse section of one of my improved tread-pieces in position
on a inandrel.

page_text: Figure 5 is a transverse section of one of my improved tread-pieces made without
a lining of inextensible fabric.
Like letters denote similar parts in all the figures.
The band a which is to form the tread piece is moulded, preferably on a suitable
mandrel or core b, with an inner lining a¹ of canvas or other suitable inextensible
material. The cross-sectional diameter of the tread-piece in its normal state is
considerably less than that of the tyre to which said tread-piece is to be applied.
This is readily seen by reference to Figures 1 and 2 which are drawn approxi-
mately to the same scale. The band may be moulded in the form of a complete or
divided tube which is thinner at one side than at the opposite side. In the former
case, after vulcanization the tube is cut at its thin portion so as to form a divided
tube. In either case the thinnest part of the divided tube is at its edges.
When
the divided tubular rubber band is secured to the tyre as shewn in Figure 2 the
curvature of said band is lessened, and owing to its inextensible lining the outer
part thereof is placed in compression. I prefer that the curvature of the band
when in place on the tyre be not more than one half that of the band in its normal
state. The tread so mounted hugs the tyre very strongly and does not tend to lift
at the edges which is an important advantage.
I sometimes provide the mandrel or core b, when such is used for moulding a
complete tube, with a groove or nick 6' extending along the same as shewn in
Figure 4 so as to guide the knife or other instrument when cutting the tube
vulcanized thereon.
I prefer that the tread-piece should be moulded in the form of a complete circle
of a diameter suitable to the wheel for which it is intended before the same is
vulcanized, but said tread-piece may be made in a straight length and vulcanized
and then joined at the ends.
The canvas or other lining is preferably placed on the mandrel with its threads
extending transversely across the same; when the tread-piece is vulcanized endless
or in a complete circle I preferably form the lining from an endless band cut from
a woven tube of a diameter approximately equal to that of the arched tread when
finished, I thus make the said tread without a transverse joint. When a circular
mandrel or core is used I sometimes make a joint therein and thread a length of
woven canvas tube thereon, or I sometimes fortn an inextensible backing to the
rubber bands by winding a suitable thread, cord or the like, closely round the
mandrel or core and secure the rubber or the like thereto by vulcanizing or
otherwise. The aforesaid canvas lining may if desired be applied to the mandrel
so that the threads thereof extend diagonally or in other suitable directions.
I sometimes form the tread-piece with extended thin flaps c which cover the sides
of the tyre. In such cases said tread-piece is vulcanized in the form shewn in
cross section in Figure 3. When such a tread piece is applied to a tyre the flaps
will not of course be in compression but the tread portion proper will be compressed
as herein before described.
I sometimes dispense with the inextensible lining as shewn for example in
Figure 5, in which case when the curvature is reduced as shewn by the dotted lines
the outer surface is placed in compression notwithstanding that the inner surface
can stretch. This compression is less than that produced when an inextensible
lining is used, but is in many cases sufficient for imparting the desired wearing
qualities to the band.
I may make the band of a combination of two or more kinds of rubber the
innermost portion of the band being made of rubber which is less extensible than
the rubber forming the outermost portion thereof.
My improved compressed band or tread may be applied to the outside of a
pneumatic tyre of any description whether such tyre is or is not provided with a
separate air tube.
In the former case, that is to say, when the tyre has a separate air tube, the
compressed rubber band is preferably secured to the outer inextensible jacket or

page_text: cover of the tyre after the latter has been covered with a layer of thin flexible
rubber or like material.
I sometimes line the inextensible backing of the band with a thin layer of rubber
prepared in a manner most suitable for securing the same by solution or otherwise
to the tyre.
In some
cases my improved rubber tread or band may be moulded with
corrugations or other suitable designs.
My improved band is especially suitable for use with tyres of large cross-sectional
diameter such as those employed on the wheels of heavy vehicles, but it may
obviously be used with the tyres of velocipede and other light wheels.
Having now particularly described and ascertained the nature of my said.inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The combination, with a pneumatic tyre, of an arched rubber tread-piece the
outer surface of which is in compression, either with or without an inextensible
fabric lining for said tread-piece and with or without a layer of rubber between
said tread piece and tyre, substantially-as, and for the purpose, specified.
2. For a pneumatic tyre an arched rubber tread-piece the curvature of which,
when the same is in place on the tyre is approximately half the curvature of the
tread-piece before being applied to the tyre, for the purpose specified.
3. For a pneumatic tyre an arched tread-piece constructed according to either or
any of the methods hereinabove described, for the purpose specified.
Dated this 18th day of September 1894.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.