Improvements in or Connected with Pneumatic Tyres for Wheels.
Year: 1898

page_text: Date of Application, 17th Sept., 1898
Complete Specification Left, 17th June, 1899-Accepted, 16th Sept., 1899
PROVISIONAL SPECIFICATION.
Improvements in or Connected with Pneumatic Tyres for
Wheels.
I, AXEL EDUARD KULLBERG, of The Central Palace, Stockholm, in the Kingdom
of Sweden, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to pneumatic tyres for wheels and is designed to provide
means whereby such tyres may be automatically inflated to any desired degree
of pressure or hardness by the rotation of the wheel during the travel of the
vehicle to which such tyres are applied.
A further and important feature of my invention is the provision of a device
as above described so constructed that, or provided with means whereby, it will
be automatically brought into operation when the tyre becomes partially deflated
and will cease to operate as soon as the tyre is reinflated to any predetermined
degree of hardness.
According to one form of my invention I provide, either within the air tube or
adjacent thereto, a compressible air bulb or chamber of any suitable shape. This
bulb is provided with two non-return valves through one of which atmospheric
air enters said bulb, and through the other of which said air can pass into the air
tube of the tyre. The bulb is self expanding and is so disposed that, when the
tyre becomes partially deflated so that it is flattened at the point where it bears
on the ground, said bulb will be compressed as it passes this point and will thus
inflate the tyre automatically. As soon as the tyre is inflated to such a degree
that the aforesaid flattening is not sufficient to compress the bulb, this automatic
inflation will cease. Means may be provided for varying the dimensions of the
bulb or the amount of its projection towards the periphery of the tyre so that the
degree of hardness to which the tyre will be inflated may be varied at will.
Instead of employing a compressible bulb I may employ an air pump mounted
on the wheel rim, the piston rod or plunger of which pump projects towards the
periphery of the tyre so as to be operated in the same manner as above described
when the aforesaid flattening of the tyre occurs. I prefer to employ a broad flat
plate, which may be in the form of a spring attached at one end to the wheel rim,
against which the end of the said rod or plunger bears. Means may be provided
for limiting the extent of projection of the rod or plunger, so as to vary the degree
of inflation of the tyre; or this purpose may be effected by an adjustable safety
valve device.
I sometimes combine with this pump a hand lever or rod by means of which the
piston may, if desired, be operated by hand.
Instead of causing said pump to be operated by reason of the aforesaid flatten-
ing of the tyre, it may be operated by an eccentric, say, on the spindle of the
wheel bearing, the pump cylinder being disposed in any convenient position
between the bearing and the wheel rim and being in communication with the air
chamber through a small tube. Or the said pump cylinder may be located in the
barrel or casing of the wheel bearing, longitudinally of such barrel, and the

page_text: pump piston be provided with a laterally projecting pin entering a spiral cam
groove formed in the spindle of the bearing, whereby said piston is reciprocated
as the wheel revolves. These pumps may be adapted to be put into and out of
operation by links or levers operated by the rider, but in each case I prefer to
employ a safety valve device provided with adjustable means for limiting the
extent to which the tyre will be inflated as above mentioned. The arrangement
may be such that the pump is automatically put out of operation upon the
actuation of the said valve, or an audible signal is given upon hearing which the
rider may himself put the pump out of operation.
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in or Connected with Pneumatic Tyres for
Wheels.
I, AXEL EDUARD KULLBERG, of The Central Palace, Stockholm, in the Kingdom
of Sweden, 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:-
-
This invention relates to pneumatic tyres for wheels and is designed to provide
means whereby such tyres may be automatically inflated to any desired degree
of pressure or hardness by the rotation of the wheel during the travel of the
vehicle to which such tyres are applied.
A further and important feature of my invention is the provision of a device
as above described so constructed that, or provided with means whereby, it will
be automatically brought into operation when the tyre becomes partially deflated
and will cease to operate as soon as the tyre is reinflated to any predetermined
begree of hardness.
In the accompanying drawings I have shown sections of portions of pneumatic
tyres having my improved means for automatically inflating the same applied
thereto, in which Figure 1 is a longitudinal section of a portion of a tyre fitted
with one form of my invention, Figure 2 is a transverse section of a tyre showing
a modified form of my invention applied thereto, and Figures 3, 4, and 5 illustrate
further modifications, Figures 4 and 5 being transverse sections, and Figure 3
a longitudinal section and elevation.
According to my invention I provide within the air tube A, Figure 1, two
partitions, B, forming a compressible air bulb or chamber C of any suitable
shape. This bulb or chamber is provided with a non return valve D through
which the air can pass into the air tube of the tyre, and with a second non-
return valve E in the side of the chamber C adjacent to the rim F of the wheel
through which air is drawn into the chamber C. The bulb C is self expanding and
is so disposed, that, when the tyre becomes partially deflated so that it is flattened
at the point where it bears on the ground, said bulb will be compressed as it
passes this point and will thus inflate the tyre automatically.
The arrangement, therefore, has the effect that, when the bulb or chamber C
during the rolling of the wheel is compressed against the ground, the air within
the bulb or chamber C is forced through the non-return vaive into the tyre A,
and as the bulb or chamber meanwhile during the continued rotation of the tyre,
again resumes its original shape, it follows that the air within the same becomes

page_text: rarefied, resulting in the drawing in through the valve E of a quantity of air
from without. This quantity of air in its turn is forced in the aforesaid manner
into the tyre A when the bulb or chamber becomes compressed during the next
revolution. In this way during the rotation of the wheel a continual injection
of air can be obtained whenever the pressure within the tyre is less than the
normal.
When this normal pressure has been attained or in any way exceeded, the
valve D no longer opens and the air which enters the bulb or chamber through
the valve E passes out again through a safety-valve G.
Instead of arranging the bulb or chamber C as above described the same may be
applied separately outside the tyre, either at the side of same so that during the
travel of the wheel it will come into contact with the ground and thus become
compressed, or in the centre of the wheel, where it can be acted upon by an
adjustable rod fixed radially to the wheel, the outer extremity of the said rod
projecting somewhat beyond the wheel tyre so as to come into contact with the
ground. The bulb or chamber can also be constructed like ordinary bellows or
like an air pump with cylinder and piston.
In Figure 2 there is illustrated a device according to which the bulb or
chamber C is applied outside the tyre at the side of same, so that during the
travel of the wheel, the said bulb or chamber C will come into contact with the
ground, and thus be compressed.
In Figure 3 the bulb or chamber C is shown as situated near the centre of the
wheel, when it can be acted upon by the rod r, fixed radially to the wheel.
In Figure 4 the bulb is illustrated as having the form of an ordinary bellows,
fixed to the tyre in the same manner as shewn in Figure 2.
In Figure 5 the bulb or chamber C is illustrated as being an air-pump chamber,
fitted with a piston having a flexible diaphragm pl. When the clamp t comes
into contact with the ground the piston is moved upwards or into the chamber
thus forcing the air contained in the chamber thus forcing the air contained in
the chamber the valve v and tube into the interior of the tyre; during this
movement the diaphragm closes the openings in the piston. When the clamp
leaves the ground it is moved together with the piston, in virtue of the elastic
properties of the tyre, in such manner as to move said piston outwards in the
chamber, the openings in the piston then becoming free and air from outside
being thus enabled to enter the bulb or chamber which has become partially
exhausted.
The arrows shewn in the several figures of the drawings indicate the course
taken by the air during the operation of the device.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. In pneumatic tyres for wheels, the arrangement, within the air-tube con-
stituting the tyre A of two partitions (B) at a suitable distance from each other,
which together with the adjacent portion of the tyre form a high pressure bulb
or air chamber (C), similar to the remaining portion of the tyre, in the outer wall
of which, formed by the tyre, is inserted a valve E for admitting the air from
without into the chamber, a valve D arranged in one of the partitions (B) through
which the air can pass from the air chamber C into the tyre A so that when
the air bulb during the travel of the wheel is alternately compressed and distended,
an automatic inflation of the tyre is effected.
2. In the arrangement above described, the modification in which the air bulb
or chamber (C) or an ordinary bellows or air pump is applied outside the tyre,
as for instance at the side of same or in the centre of the wheel in which case
the air bulb or bellows during the rotation of the wheel is arranged either for
immediate contact with the ground or connected with an adjustable rod or piston,

page_text: one end of which projects beyond the wheel tyre so that the same may owing to
the adjustability of the rod, come into contact with the ground when the wheel
travels forward thereon.
Dated this 17th day of June 1899.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.