Improvements in the Manufacture of Indiarubber Tyres for the Wheels of Vehicles.
Year: 1899

page_text: Date of Application, 26th Apr., 1899
Complete Specification Left, 30th Nov., 1899-Accepted, 17th Feb., 1900
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Indiarubber Tyres for the
Wheels of Vehicles.
We, HENRI FALCONNET and MAURICE PÉRODEAUD, both of Choisy-le-Roi
(Seine), in the Republic of France, Engineers, do hereby declare the nature of
this invention to be as follows:-
The conditions with which a wheel tyre must comply are difficult to realise
in practice, because they are up to a certain point, contradictory. The diffi-
culties which are encountered in order to give the tyre resiliency and flexibility
on the one hand, and on the other hand the power to resist the various strains
of traction, compression, friction, cutting, tearing and the like, may well be
conceived.
Logically, when tyres are employed which are entirely resilient, it is pre-
ferable to give them a certain amount of resistance, and consequently a relative
rigidity at the external periphery, more particularly at the points where they
are in contact with the ground and where they receive the reaction of the
latter, and the action of the weight of the vehicle, transmitted by the wheel
on which this tyre is fixed; on the other hand the central part of the tyre
must have great elasticity.
These conditions are well realised by pneumatic tyres, but the want of
strength of these latter renders their use difficult and even dangerous in the
case of heavy vehicles.
Efforts have been made to make solid resilient tyres and these tyres have
been composed of layers of different materials of variable elasticity, combined
by various processes of adhesion, grouping and fixing. Such tyres have only
a relative cohesion. In another specification filed contemporaneously with this,
we have in effect, described a process enabling the cohesion of tyres thus made
to be increased.
The invention which forms the object of the present application, relates
to a solid rubber tyre obtained by means of a single original substance such
as pure commercial rubber or a mixture of same converted (after its manu-
facture into a tyre) by a special process enabling a resiliency or flexibility to
be imparted to it which increases from the periphery to the centre. Thus
assuming for instance that we start with a homogeneous tyre of ordinary
commercial rubber, such as is shown in the accompanying drawings in trans-
verse section in Figure 1. the process which we will now describe enables
successive zones such as a b c (Figure 2) the number of which is variable at
will, to be determined therein, the axial zone e being of great flexibility,
the zone of a less flexibility and the zone a still less than b.
The principle of the method employed in our invention consists in sub-
jecting the tyre, formed by known industrial methods, to a series of vulcaniza-
tions alternating with subsequent refrigerations, the number of alternate opera-
tions corresponding to the number of zones of different flexibility, such as
be which it is desired to form in the tyre. Our method is preferably employed
a

page_text: with an indiarubber as far as possible free from mineral substances which are
good conductors of heat.
The prepared tyre is heated at first to the temperature of 110 degrees
Centigrade, that is to say to about the maximum temperature necessary for
producing a vulcanization; this first slight vulcanization is extended to
the whole mass p and for this object we maintain this temperature until the
vulcanization has had time to spread from the periphery to the centre. Then
we congeal the vulcanized tyre for the first time in a refrigerating apparatus
at a temperature varying between -10 & -20 degrees Centigrade, we maintain
that temperature until the temperature is the same throughout the whole tyre.
The tyre of which the whole mass is congealed in then vulcanised afresh, and
for this object, carried to a temperature higher than in the first case, say to
150 degrees Centigrade. This temperature is not maintained long enough for
the fresh vulcanization of the tyre to spread to the axial zone c in which we
thus create a sort of reserve of cold, the bad conductibility of india rubber
facilitating this phenomenon. A tyre, the manufacture of which is interrupted
at this moment will then comprise two zones of different flexibility, viz.-
the axial zone c which is very flexible and a peripheral zone of a less flexibility
extending from the part e to the surface.
In order to divide the mass extending from e to the periphery into a zone b
of greater flexibility than the outer zone a, it is sufficient after the second
vulcanization at high temperature to congeal the tyre afresh, and then to
subject it to a third vulcanization for a time short enough for the heating to
remain confined to the layer a by reason of the reserve of cold in the other
layers.
We lay stress on this point that the successive vulcanizations must necessarily
alternate with congealations and it is these alternations which enable the im-
proved result indicated by us to be attained. As regards the number of these
alternations and their durations, of course they may vary according to the
number of zones which it is desired to produce in the mass of the tyre by
reason of the special uses to which the tyre is to be put and according to the
degree of flexibility, resiliency or resistance which it is desired to obtain.
Although this process enabling zones of a flexibility increasing from the
periphery to the centre to be obtained in the mass of a tyre is more particu-
larly and more advantageously applicable for a tyre prepared industrially from
a homogeneous mass: it may also be employed with a tyre prepared with frag-
ments of different substances joined together by adhesion and pressure by any
of the known methods, and more particularly by the improved method described
in our aforesaid specification of this day's date.
Dated this 25th day of April 1899.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicants.
Improvements in the Manufacture of Indiarubber Tyres for the
Wheels of Vehicles.
We, HENRI FALCONNET and MAURICE PÉRODEAUD, both of Choisy-le-Roi 4
(Seine), in the Republic of France, Engineers, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement: —
The conditions with which a wheel tyre must comply are difficult to realise

page_text: in practice, because they are up to a certain point, contradictory. The dith-
culties which are encountered in order to give the tyre resiliency and flexibility
on the one hand, and on the other hand the power to resist the various strains
of traction, compression, friction, cutting, tearing and the like, may well be
conceived.
Logically, when tyres are employed which are entirely resilient, it is pre-
ferable to give them a certain amount of resistance, and consequently a relative
rigidity at the external periphery, more particularly at the points where they
are in contact with the ground and where they receive the reaction of the
latter, and the action of the weight of the vehicle, transmitted by the wheel
on which this tyre is fixed; on the other hand the central part of the tyre
must have great elasticity.
These conditions are well realised by pneumatic tyres, but the want of
strength of these latter renders their use difficult and even dangerous in the
case of heavy vehicles.
Efforts have been made to make solid resilient tyres and these tyres have
been composed of layers of different materials of variable elasticity, combined
by various processes of adhesion, grouping and fixing. Such tyres have only
a relative cohesion.
The invention which forms the object of the present application, relates
to a solid rubber tyre obtained by means of a single original substance such
as pure commercial rubber or a mixture of same converted (after its manu-
facture into a tyre) by a special process enabling a resiliency or flexibility to
be imparted to it which increases from the periphery to the centre. Thus
assuming for instance that we start with a homogeneous tyre of ordinary com
mercial rubber, such as is shown in the drawings accompanying the Provisional
Specification in transverse section in Figure 1, the process which we will now
describe enables successive zones, such as a b c (Figure 2) the number of which
is variable at will, to be determined therein, the axial zone being of great
flexibility the zone of a less flexibility and the zone a still less than b.
The principle of the method employed in our invention consists in sub-
jecting the tyre formed by known industrial methods, to a series of vulcaniza-
tions alternating with subsequent refrigerations, the number of alternate opera-
tions corresponding to the number of zones of different flexibility, such as
abc which it is desired to form in the tyre. Our method is preferably em-
ployed with an indiarubber as far as possible free from mineral substances
which are good conductors of heat.
C
The prepared tyre is heated at first to the temperature of 110 degrees
Centigrade, that is to say to about the maximum temperature necessary for
producing a vulcanization; this first slight vulcanization is extended to
the whole mass and for this object we maintain this temperature until the
vulcanization has had time to spread from the periphery to the centre. Then
we congeal the vulcanized tyre for the first time in a refrigerating apparatus
at a temperature varying between -10 & 20 degrees Centigrade, we maintain
that temperature until the temperature is the same throughout the whole tyre.
The tyre of which the whole mass is congealed is then vulcanized afresh, and
for this object, carried to a temperature higher than in the first case, say to
150 degrees Centigrade. This temperature is not maintained long enough for
the fresh vulcanization of the tyre to spread to the axial zone e in which we
thus create a sort of reserve of cold, the bad conductibility of indiarubber
facilitating this phenomenon. A tyre, the manufacture of which is interrupted
at this moment will then comprise two zones of different flexibility, namely,
the axial zone e which is very flexible and a peripheral zone of a less flexibility
extending from the part c to the surface.
In order to divide the mass extending from c to the periphery into a zone b
of greater flexibility than the outer zone a, it is sufficient after the second
vulcanization at high temperature to congeal the tyre afresh, and then to

page_text: .subject it to a third vulcanization for a time short enough for the heating to
remain confined to the layer a by reason of the reserve of cold in the other
layers.
We lay stress on this point that the successive vulcanizations must necessarily
alternate with congealations and it is these alternations which enable the im
proved result indicated by us to be attained. As regards the number of these
alternations and their durations, of course they may vary according to the
number of zones which it is desired to produce in the mass of the tyre by
reason of the special uses to which the tyre is to be put and according to the
degree of flexibility, resiliency or resistance which it is desired to obtain.
Although this process enabling zones of a flexibility increasing from the
periphery to the centre to be obtained in the mass of a tyre is more particu-
larly applicable for a tyre prepared industrially from a homogeneous mass; it
may also be employed with a tyre prepared with fragments of different sub-
stances joined together by adhesion and pressure by any of the known methods.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that
what we claim is:-
The process of manufacturing indiarubber tyres for the wheels of vehicles
which consists in creating, in the mass of the tyre, zones of different resiliency
or flexibility increasing from the periphery to the centre, by subjecting the
tyre formed by the ordinary industrial methods and subjected to a first general
vulcanization, to a series of refrigerations (at temperatures below 0°) alter-
nating with vulcanizations at high temperature of increasingly shorter duration
whereby the vulcanization interrupted by the congealing of the core of the
tyre, is effected to decreasing depths, substantially as hereinbefore set forth.
Dated this 29th day of November 1899.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicants.