Improvements in the Manufacture of Pneumatic Tyres for the Wheels of Road Vehicles.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Pneumatic Tyres for the Wheels
of Road Vehicles.
I, ERNEST FLEMING, of 22, Highfield Terrace, King Cross, Halifax, in the
County of York, Engineer, do hereby declare the nature of this invention to be as
follows, that is to say:-
In following the usual method of production of pneumatic tyres for the
wheels of road vehicles, the inflating tube has been enclosed by an outer
covering framed by a layer of rubber over a canvas ground or back. It is to the
production of this canvas ground that my invention particularly relates, and in
accordance therewith I follow such method of production as to enable said cover-
ing on the inflation of the tube within it to grip the rim of the wheel to which
it is applied, by which means any additional devices for securing it upon said
rim are dispensed with.
This canvas part of the covering I produce by a process of knitting either on
what are known as circular machines, or on what are known as flat machines.
When I employ circular knitting machines, I have the cylinders in same upon
which the needles are mounted of a diameter suitable to produce the fabrics the
desired size to fit over the rim of the wheel to which they have to be applied, by
which means the said fabric is made of the proper dimensions and that in one entire
piece or endless.
To enable the canvas thus produced to grip the rim on the inner tube being
inflated I form the edges of such canvas of considerably thicker yarn and gradually
reduce the thickness of said yarn as I approach the centre of fabric from each
side thus on this fabric with its indiarubber covering, being placed over the
inflating tube, when this latter is inflated the central part of its cover will be
forced radially from the rim causing the thinner thread in such central part to
drag or pull the thicker ones or in other words causing the threads approaching
the central part of the fabric to act upon those leading up to the edges in such
a manner that the extra space through which they are made to pass is allowed
for by those threads at the edges occupying a less space.
When I employ flat machines for the production of these fabrics I knit them
of the exact formal desire, that is to say, I form the edges of the fabric shorter or to
fit against the wheel's rim, while the central part is made longer or larger in
diameter to take over the inflated tube on the said rim, this forming of the fabric
being by the process known as "raising and narrowing."
When these shaped fabrics are covered with indiarubber and mounted over
the inflating tube on the rim, when such tube is inflated the central parts of the
fabric draw or pull the edges of same so as to grip the rim as desired.
Dated this 29th day of July 1898

page_text: Improvements in the Manufacture of Pneumatic Tyres for the Wheels
of Road Vehicles.
I, ERNEST FLEMING, of 22, Highfield Terrace, King Cross, Halifax, in the
County of York, Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement, that is to say:-
In following the usual method of production of pneumatic tyres for the
wheels of road vehicles, the inflating tube has been enclosed by an outer
covering formed by a layer of rubber over a canvas ground or back. It is to the
production of this canvas ground that my invention particularly relates, and in
accordance therewith I follow such method of production as to enable said cover-
ing, on the inflation of the tube within it, to grip the rim of the wheel to which
it is applied, by which means any additional devices for securing it upon said
rim are dispensed with.
In order that this invention may be readily understood, I have hereunto appended
a sheet of drawings, in which
Fig. 1 is a sectional view of a tyre or cover (and its rim) constructed in accordance
with my invention, the proportionate thickness in the several parts of said cover
being somewhat exaggerated so as more clearly to show this invention.
Fig. 2 is a sectional end view of the canvas ground forming part of the cover, also
exaggerated in its varied thickness.
Figs. 3 and 4 are similar views to Figs. 1 and 2, but are illustrative of a slight
modification in the construction of the canvas part of the tyre as hereinafter
described.
Fig. 5 is a perspective view drawn to a reduced scale of an entire cover made in
accordance with the method illustrated by Figs. 1 and 2.
Fig. 6 is a similar view to Figs. 1 and 3, but illustrates a modification hereinafter
described.
Fig. 7 is a perspective view of a portion of a cover made in accordance with the
method illustrated by Fig. 6, said cover being shown as mounted upon a rim.
Similar letters and figures of reference indicate similar parts throughout the
several views.
The canvas part a of the covering referred to is in accordance with my inven-
tion produced by a process of knitting either on what are known as circular
machines, or on what are known as flat machines.
When I employ circular knitting machines, I have the cylinders in same upon
which the needles are mounted of a diameter suitable to produce the fabric a the
desired size to fit over the rim of the wheel to which they have to be applied,
by which means the said fabric a is made of the proper dimensions and that in one
entire piece or endless.
To enable the canvas a thus produced to grip the rim, on the inner tube c being
inflated, I form the edges ala of such canvas a of considerably thicker yarn, say 4
out of sevenfold yarn, and gradually reduce the thickness or number of folds of
such yarn until the points 3 3 are reached, where the part is formed of two-
fold, these relative thicknesses being very suitable, although it will be seen that
they may be considerably varied. It will thus be seen that on the fabric a
with its india-rubber covering d being placed over the inflating tube c, when this 4
latter is inflated the central part of the cover will be forced radially from
the rim causing the thinner thread in such central part all to drag or pull the
thicker ones or in other words causing the threads approaching the central part all
of the fabric to act upon those leading up to the edges a¹ in such a manner that

page_text: the extra space through which they are made to pass is allowed for by those
threads at the edges a¹ occupying a less space thus said edges a¹ a¹ are firmly
drawn against or caused to grip the rim b.
I find that, instead of using thicker yarn or a greater number of threads of yarn
at the edges of the covers as above described, the same result may be attained by
using the same thickness of yarn at all parts of the cover and producing shorter
stitches at the edges since by reason of having shorter stitches the interstices
between them are as fully occupied or filled up by one thread as larger stitches
are by a number of threads, and these shorter stitches I produce by the adjust-
ment of the feed wheels in the well known manner or by taking only each alter-
nate needle in each round one series of needles being taken for one round and the
adjoining series for the next and succeeding round.
In order to afford greater resistance to the forces tending to remove the tyre a
from the rim b, I may form extra edge parts a³ (see Figs. 3 and 4) of an appropriate
width, and, say, out of two-fold yarn, the outer edges being folded over each
other to form rolls or thickened parts at, so that on the india-rubber covering d
being cemented to extend over the cover a from one part a¹ on one side to that a on
the other side, and on said covering being then placed upon the rim b so that one
thickened part af may be brought into contact with the thinner part a³ on each
side, when this cover is inflated, the lateral distensions cause the entire canvas
part a to contract circumferentially and so grip the rim b.
When I employ flat machines for the production of these fabrics, I knit them of
the exact form Ldesire, that is to say, I commence with knitting the proper number
of stitches around the edge f (see Figs. 6 and 7) and increase such number of
stitches until the extremity of the periphery is reached as at fi, after which I
commence to narrow or reduce the number of stitches until the other edge fis
reached by which means I can form a tyre of nearly any desired shape in cross
section and one that will on being increased in size laterally decrease in length
circumferentially and will so grip the rim upon which it has to be used, and in
this case I may if desired also form the outer edges a³ and overlapping parts at as
shown in Figs. 3 and 4.
Instead of making the edges a¹ a¹ of increased thickness I may employ a different
kind of yarn or fibre for producing these parts of increased strength and rigidity
or I may use finely drawn wire to form these thickened parts, the principle of the
contracting of the tyre on to the rim irrespective of the shape in cross section of this
latter being the same in all the several modifications.
It will be seen that by forming the overlapping parts 3 to have a covering of
rubber or the like which will render them airtight when folded, the use of an
inner inflating tube is not necessary.
After the fabric is produced as above described I stretch it on a forming wheel or
lisc and mount the rubber covering & thereon in the manner well known to produce
he complete covering.
Having now particularly described and ascertained the nature of my said
nvention, and in what manner the same is to be performed, I declare that what
claim is:
1. A knitted fabric for use in pneumatic tyres substantially as described.
2. The method of producing a fabric for use in pneumatic tyres by knitting
ubstantially as described.