Improvements in or relating to Pneumatic Tyres and other Articles Manufactured of India Rubber
Year: 1894

page_text: Date of Application, 27th Oct.. 1894
Complete Specification Left, 27th Aug., 1895-Accepted, 19th Oct.,
1895
PROVISIONAL SPECIFICATION.
Improvements in or relating to Pneumatic Tyres and other Articles
Manufactured of India Rubber.
THOMAS SLOPER of 11, 12, 14 & 15 Brittox Devizes in the County of
Wiltshire Inventor do hereby declare the nature of this invention to be as
follows:-
This invention relates to certain improvements in pneumatic tyres & to a new
fabric for strengthening the same which is also applicable to other articles made of
india rubber.
Pneumatic tyres are usually made with canvas or fibrous threads in combination
with india rubber.
I prefer to use a special fabric for reinforcing the rubber in which each thread
is more or less connected with its neighbouring threads on each side, but I generally
avoid arranging one thread to cross another at or near right angles. I prefer to
make this fabric in such a manner that each thread winds round its neighbouring
threads on each side alternately, somewhat in the same manner as in a net but
preferably (though not necessarily) without knots. For making this fabric
generally use a machine of special construction somewhat resembling the
machines used in the manufacture of wire netting. The fabric may be made
directly on to the tyre or other article to be strengthened if desired but for
convenience prefer to unite the fabric to a thin sheet of india rubber which is
afterwards used in the manufacture of the tyre or other article.
I
When intended for use with pneumatic tyres the fibrous threads are arranged
in the fabric sufficiently straight to take a direct strain although each thread
winds round its neighbouring threads as described & I prefer that the threads
shall be set longditudinally or transversely in the fabric & not diagonally as in a
braid.
It will be obvious that when a fabric so constructed is under tension the
movement of oue thread will affect the threads on each side or if the tension should
be reduced in one thread that of its neighbouring threads will also be reduced.
Also if the fabric is under tension in both directions (that is, in the direction of
the fibrous threads & sideways or at right angles to the threads) then alteration of
the tension at one part will more or less affect all neighbouring parts.
A pneumatic tyre may be constructed of one or more layers of this fabric having
the threads crossing the tyre transversely only, in which case the pressure of the
wheel upon the ground will reduce the strain upon the threads immediately under
the wheel, and this will reduce the side strain upon the threads on each side of the
part in contact with the ground.
It will be obvious that any reduction in the side strain will cause the threads of
the fabric to slightly lengthen, or in other words to become more straight. This
lengthening of the threads will on account of the air pressure cause the tyre to
increase in size at the point where it makes or leaves contact with the ground in
front & behind the wheel respectively. This increase in the size of the tyre
behind the wheel would be a decided advantage if it were not for the equal
increase in front of the wheel which counteracts it. Now one of the objects of my
invention is to make a tyre in which the increase of size occurs at the back of the
wheel but is prevented from forming in front of the wheel.
:

page_text: For this purpose I make a tyre as above described having one or more layers of
the special fabric arranged transversely & in addition to this I arrange special
diagonal threads slanting downwards & forwards from the bottom of the wheel rim
to the tread surface on each side of the tyre, as described in a previous Specification
& for which arrangement I have applied for Letters Patent.
The flattening or lateral expansion of the tyre immediately under the wheel puts
strain on these diagonal threads which thus prevent any reduction in the side.strain
of the threads in the special fabric towards the front of the wheel. This consequently
still further reduces the side strain in the special fabric at the rear of the wheel
which by allowing the threads to lengthen increases the size of the tyre at
this part.
The tension of the diagonal threads also increase the side strain on the threads
of the special fabric at the part in front or where the tyre first makes contact with
the ground and as will be obvious the effect of this increase is to reduce the size of
the tyre at this point by shortening the transverse threads or in other words by
causing them to take a more zigzag form.
To facilitate the manufacture of the tyre a band of thin rubber may be made
having diagonal or looped threads set or bent at the desired angle attached thereto.
To make this band I use another machine of special construction somewhat
resembling a wire covering machine. The thread is wound in this machine on to a
travelling strip of rubber and endless travelling bands which are in the position to
receive it. The tubular winding of thread thus formed is carried forward by the
bands and part of it is then secured to the travelling strip of india rubber by any
suitable means. The other part of the tubular winding of thread is not secured to
the rubber strip until it has been drawn back by a special appliance on the machine
which causes the threads to take a form or 68 set somewhat resembling the letter V.
The band is thus made with two layers of thread in one layer the threads being
transverse or straight & in the other layer they are looped or arched. For the
particular make of tyre described above the transverse threads are removed from
the band before it is used.
وو
If desired in making the special fabric first described each thread may wind
round two or more threads on each side or two threads may be arranged side by
side or other combinations may be used to attain a similar result.
In order to increase the elasticity of the fabric one fibrous thread & one plain
rubber cord may be caused to revolve round a fibrous thread & a rubber cord on
each side or the thread may be wound spirally round the india rubber cord in which
cases the rubber cord would form part of the rubber of the finished fabric after
vulcanization.
To make a rubber fabric capable of being stretched to a limited extent only in
one direction & to an unlimited extent in the other direction rubber cords wound
spirally with fibrous threads may be vulcanized together side by side, which forms
a fabric containing spiral fibrous threads which limit its degree of elasticity.
Parallel, straight, fibrous threads may be connected together by other threads
winding from one to the other alternately in which case the connecting threads may
with advantage be of smaller size than the parallel straight threads.
By a modification of the machine on which it is made one or more threads may
be arranged at intervals in the special fabric set at about right angles to the rest of
the threads, these threads being generally arranged to come at that part of the
fabric which is used for the tread surface of the tyre or for that portion of the tyre
which is inside the wheel rim.
Fine wire may be used instead of thread in the special fabric where extra strength
is required in which case the wire may be covered with fibrous thread paper or other
substance to prevent the wire from working loose in the rubber with wear, or to
prevent it from breaking by being bent at too sharp an angle.
In order that the outside or tread surface of the tyre may be longer than the
portion which is inside the rim the tyre may be made or vulcanized in the form of
a spiral coil of smaller circumference than the finished tyre the tread surface being.

page_text: arranged outside. By taking more than one ring of this coil & forming it into an
endless tyre the outer or tread portion will be under compression & thus less liable
to puncture accidentally.
A similar result may be obtained by moulding that part of the tyre which is to be
outside the wheel rim with corrugations or recesses. Thus a recess at the tread
surface may be followed by recesses at the sides alternately. The circumference
of the material forming the tyre being the same at every part upon inflating the
tyre the recesses are blown out this having the effect of compressing the rubber
forming the tyre.
'
Manufactured of India Rubber.
I, THOMAS SLOPER, of 14 & 15 Brittox, Devizes, in the County of Wilts,
House Furnisher, 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 certain improvements in pneumatic tyres and to a new
fabric for strengthening them, which is also applicable to other articles made of
india rubber. Pneumatic tyres are usually made with canvas or fibrous threads in
combination with india-rubber.
The present invention will be best understood by reference to the accompanying
drawings in which
Fig. 1 represents a portion of one form of fabric constructed according to this
invention.
Figs. 2 and 3 are views showing modified constructions of the fabric.
Figs. 1, 2 and 3 represent the fabrics at considerably greater than their natural
dimensions.
Fig. 4 is a view of portion of a tyre cover embodying my improvements and
Fig. 5 is a diagrammatic view of portion of a machine used in the manufacture
of my improved tyre cover, the part at the right of the line 5-5 for convenience
being drawn to a larger scale than that to which the part at the left hand of that
line is drawn.
Like letters indicate like parts throughout the drawings.
In carrying my invention into practice, I prefer to use a special fabric for
reinforcing the rubber in which each thread is more or less connected with its
neighbouring threads on each side, but I generally avoid arranging one thread to
cross another at or near a right angle. For the purpose of distinction I will call
this fabric a twist fabric." I prefer to make this fabric as shown in Fig. 1, in
such a manner that each thread winds round one or more of its neighbouring
threads on each side alternately.
For facilitating the understanding of the arrangement of the threads in the
differently constructed fabrics I have in each of the Figs. 1, 2 and 3 represented
one thread by a thick black line.
In Fig. 1, wherein practically all the threads are treated alike, it will be seen
that each thread winds round its neighbouring thread on each side and that
otherwise the threads are approximately straight. For example the thread A
which is the one represented by the black line, is first inclined in one direction
towards and wound round its neighbouring thread B and then is inclined in the
reverse direction and towards and wound round the neighbouring thread C thence
returning again to the thread B and so on.

page_text: Each thread may be caused to revolve round 3, 4 or more threads in the
same way as is hereinafter described in reference to Fig. 3 but in this arrangement
the threads D which in Fig. 3 are shown straight would be bent.
If desired in making the special fabric first. described each thread may wind
round two or more threads on each side, or two threads may be arranged side by
side, or other combinations may be used to attain a similar result.
As shown for example in Figs. 2 and 3 parallel, straight fibrous threads D may
be connected together by other threads E winding from one to another alternately,
in which case the connecting threads E may with advantage be of smaller size than
the parallel threads D. In Figs. 2 and 3 each thread E is shown counecting
respectively two and four of the threads D but any other number may be connected
by the threads E.
For making this "twist fabric "I generally use a machine somewhat resembling
those used in the manufacture of wire netting, laces and fancy fabrics, but I make
no claim in this Specification to any such machine. The fabric may be made
directly on the tyre or other article to be strengthened if desired, but for con-
venience prefer to secure the fabric as it issues from the machine, and
conveniently by rollers, to a thin-sheet of india rubber which is afterwards used
in the manufacture of the tyre or other article.
When intended for use with pneumatic tyres the fibrous-threads are arranged in
the fabric sufficiently straight to take a direct strain although each thread winds
round its neighbouring threads as described and I prefer that the threads shall be
set longitudinally or transversely in the fabric and not diagonally as in a braid.
By a modification of the machine one or more threads may be arranged at
intervals in the "twist fabric " to be at about a right angle to the rest of the
threads these threads being generally arranged to come at that part of the fabric
which is used for the tread surface of the tyre or for that portion of the tyre which
is inside the wheel rim.
It will be obvious that when a fabric constructed as before described is under
tension, the movement of one thread will affect the threads on each side, or if the
tension should be reduced in one thread, that of its neighbouring threads will also
be reduced. Also if the fabric is under tension in both directions (that is, in
the direction of the fibrous threads and at right angles thereto) then alteration
of the tension at one part will more or less affect all neighbouring parts.
A pneumatic tyre may be constructed of one or more layers of this fabric having
the threads crossing the tyre transversely only, in which case the pressure of the
wheel upon the ground will reduce the strain upon the threads immediately under
the wheel and this will reduce the side strain upon the threads on each side of the
part in contact with the ground. It will be obvious that any reduction in the side
strain will cause the threads of the fabric to slightly lengthen or in other words to
become more straight. This lengthening of the threads will, on account of the air
pressure, cause the tyre to increase in size at the point where it makes or leaves
contact with the ground in front and behind the wheel respectively.
This increase in the size of the tyre behind the wheel would be a decided
advantage if it were not for the equal increase in front of the wheel which
counteracts it. Now one of the objects of my invention is to make a tyre in
which this increase of size occurs at the back but is prevented from forming in
front of the wheel.
For this purpose I form the tyre of one or more layers of the before described
"twist fabric with the threads extending transversely, and special diagonal
threads G, Figure 5 arranged to slant downwards and forwards froin the bottom of
the wheel rim to the tread surface on each side of the tyre us described in my
Specification to Letters Patent No. 22650 of 1893.
The flattening or lateral expansion of the tyre immediately under the wheel
puts strain on these diagonal threads G which thus prevent any reduction in the
"side strain" of the "twist fabric threads, towards the front of the wheel.
This consequently still further reduces the side strain in the "twist fabric" at the

page_text: rear of the wheel which, by allowing the threads to straighten, increases the size
of the tyre at this part.
The tension of the diagonal threads G also increases the side strain on the
threads of the "twist fabric" thread at the part in front, or where the tyre first
makes contact with the ground and, as will be obvious, the effect of this increase
is to reduce the size of the tyre at this point by shortening the transverse threads
.or in other words, by causing them to take a more zig-zag form.
I will now describe how I prefer to use the before described "twist fabric" in
the manufacture of detachable covers for pneumatic tyres, having a combination
of trausverse threads with diagonal or arched threads, as more particularly
described in my Specifications of Letters Patent Nos. 22650 of 1893 and 385
of 1894.
I first form a continuous web of the "twist fabric" with the threads extending
at right angles to the length of the web or parallel with the axis of the ring to be
afterwards formed thereof, and I secure to each edge of this web an inelastic tape
cord wire or other inextensible edging H as shown in Figure 4. This web which,
as a whole is herein referred to as the web H is then covered by a winding of
fibrous thread laid in a particular manner by the machine illustrated in Fig. 5.
By the word "tape" when used in connection with an arrangement such as shown
in Fig. 4, I mean any suitable inelastic edging.
In this machine are provided endless travelling bands I and J (usually two
though more than that number may be used) carried on rollers arranged near
together. The web constructed as above described is then drawn through the
machine over the travelling bands I and the thread G is wound on to the top of
the web and around the underside of the travelling band J by a thread carrier P
The tubular winding of thread thus formed is carried forward as wound. The
threads are shown spaced wide apart in Fig. 5 for the sake of clearness, but I
prefer that they should be nearly or quite close together.
The rubber of the web H may be in a semi-plastic condition and a roller L
heated by steam may be provided so that, as the web passes under it, the thread
will be pressed upon and united to the rubber of the web; or other means may be
employed for fixing the thread.
The thread G below the web H clears the endless band J as it proceeds and
hangs in the form of loops. A guard may be used to prevent these thread
loops G from coming in contact with the plastic rubber prematurely.
The web is then drawn partly round a wheel or support M having a convex
rim, only a portion of this wheel is shown in Fig. 5. This wheel is preferably of
about the same circumference as the tyres for which the web is made. As the
web passes round this wheel the loops of thread K are drawn back (or they may
be moved forward) by a brush or other retarding or arranging device N and caused
to take a form resembling the letter V on the web, which latter has at this point
been caused to assume an arched or crescent form as will be readily understood
by referring to Fig. 5; by the term "arranging device" I mean any device
which will cause the threads to assume this arched or crescent form.
After the threads have been put in place by the arranging device N they are
secured to the rubber by one or more heated rollers O, or other suitable means
may be employed for securing the threads.
If a
66
twist fabric" is employed in the web of which there are no quite-straight
threads for example, such a "twist fabric' as that shown in Fig. 1 then the
transverse threads formed in the last described winding operation may be removed
if desired in order to allow the tyre cover to stretch transversely to a limited
extent, but if straight threads are employed in the "twist fabric as for example
in Figs. 2 and 3 these transverse threads may remain to reinforce them.
"
The object in stretching the web over the convex rim of wheel M before the
arched or looped threads K are fixed is in order to form the web in about its
finished shape.
I find that this is important, as if the threads G are fixed in a flat form, and the

page_text: web is then afterwards altered to its natural crescent shape, the stretching of the
centre of the web has the effect of distorting the transverse threads out of their
proper position, so that they oppose and counteract the advantages obtained by the
arched threads.
A plain ribbon of sheet rubber may be wound with thread in the machine
shown in Fig. 5 instead of the compound web above described in which case a
fabric is formed having two layers of thread that is to say one arched on one side
of the ribbon and the other straight or transverse at the opposite side.
Or two or more tapes (without rubber) may be similarly wound with thread in
which case the threads would be cemented to the tapes and the arched threads
cemented to the transverse threads.
I am aware that pneumatic tyres have been made with ordinary net, stretched
for a restraining material and I make no claim to such an arrangement. Not only
is such fabric liable to stretch, but I find that if fibrous threads are bent or tied at
a sharp angle as in a net, they are liable to break at the sharp bends, in
consequence of the strain or tension coming mostly on the fibres upon one side of each
thread. In my twist fabric as illustrated in Fig. 1 the threads are nearly straight
and they extend only partially round each other moreover the fibres in one thread
cross those in another thread at an acute angle and not at an obtuse or right angle
as in a net.
By a modification of the machine illustrated in Fig. 5 a band or web may he
made with two series of "looped" threads, that is to say, one on each side of the
strip of rubber. In this case the tubular winding of threads would be wound upon
and fixed to two separated tapes (or other inextensible material) and these tapes
would afterwards be brought nearer together. Two "setting" brushes would be
employed in this case, one on each side of the web or strip of rubber. If desired
the threads on one side of the web may be caused to "bend" in the opposite
direction to those on the other side, or other modifications may be made without
departing from the spirit of the invention.
The special fabrics herein described may be used for restraining rubber articles
other than pneumatic tyres, for instance flexible rubber hose pipe, by the employ-
ment of this material therein may be restrained transversely while free to extend
longitudinally.
The fabric may however be applied to various other rubber articles requiring a
restraining material inextensible in one direction for example solid or cushion tyres,
which may with advantage be restrained by plies or windings of the fabric
vulcanized in the rubber.
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 "twist fabric" for restraining india rubber having approximately straight
but intertwined threads secured to sheet rubber extensible in one direction but not
in the direction perpendicular thereto.
2. In a fabric for restraining india rubber such as claimed in Claim 1 the
arrangement of the threads substantially in the manner described and illustrated in
Figure 1 of the accompanying drawings.
3. A fabric for pneumatic tyres made by intertwining parallel fibrous threads
each thread passing round its neighbouring threads at an acute angle and in actual
contact therewith only part of the way round substantially as described and
illustrated in Figure 1 of the accompanying drawings.
4. In a fabric for restraining india rubber such as claimed in Claim 1 the
combination with a number of parallel straight threads of a number of other
threads each of which is wound around two or more of the straight threads
substantially as described and illustrated by way of example in Figures 2 and 3 of
the accompanying drawings.
5. In a tyre cover the combination with a strip of fabric constructed as set forth

page_text: in the preceding claims of inextensible edgings substantially as described and
illustrated by way of example in Figure 4 of the accompanying drawings.
6. A tyre cover constructed of a strip or ring of fabric formed as set forth in
Claim 1 or 2 or 3 the threads extending in a direction approximately transverse-
to the circumference of the strip substantially as described.
7. In a tyre cover the combination with a strip of fabric constructed as set
forth in Claim 1, 2, 3 or 4 of diagonal loops such as G either independent of or
integral with each other substantially as and for the purpose described and
illustrated in the accompanying drawings.
8. Applying to a strip of material or a tyre cover inclined thread loops such
for example as those described in Specification of Letters Patent No. 22650 of
1893 by passing the strip or tyre cover over one of a pair of endless bands
winding the thread around the strip and endless bands passing the thread-encircled
strip on to a wheel-like support moving the thread loops backwards or forwards
by an arranging device" and securing the thread to the strip substantially as
described.
9. Constructing a band or cover for a pneumatic tyre by winding fibrous.
thread on to a web or tapes kept in position and carried forward fixing parts of
the so-formed loops to the web or tape altering the position of the remaining
portions of the loops by drawing them backwards or forwards and subsequently
fixing them while on a convex support substantially as described.
10. In a machine for applying to a strip of material or a tyre cover inclined
loops such for example as those described in Specification of Letters Patent
No. 22650 of 1893 the combination with two endless bands such as I and J of
a thread carrier P adapted to rotate around the bands all arranged and operating
substantially as illustrated in Figure 5 of the accompanying drawings.
11. In apparatus such as represented in Figure 5 for winding and fixing fibrous
threads on to a web or on to tapes an arranging device adapted for altering the
position of a portion of each loop after another portion has been fixed substantially
as described.
12. In a machine for applying to a strip of material or a tyre cover inclined
loops such for example as those described in Specification of Letters Patent
No. 22650 of 1893 the combination with two endless bands such as I and J and a
thread carrier P adapted to rotate around the bands of a support for the thread-
encircled strip and a thread-arranging device such as the revolving brush N
substantially as and for the purpo-e described and illustrated in Figure 5 of the
accompanying drawings.
13. In a machine for applying to a strip of material or tyre cover inclined loops.
such for example as those described in Specification of Letters Patent No. 22650)
of 1893 the combination of two endless bands such as 1 and J a thread carrier P
adapted to rotate around them a wheel-like support such as M for the thread-
encircled strip a thread arranging device such as the revolving brush N and heated
rollers such as L and O for securing the thread to the strip all arranged and
operating substantially as described and illustrated in Figure 5 of the accompanying
drawings.
Dated this 24th day of August 1895.
THOMAS SLOPER.
Boult & Wade,
Agents for the Applicant.