Improvements in or relating to Pneumatic Tyres.
Year: 1899

page_text: Date of Application, 15th Sept., 1899
1000
L
PROVISIONAL SPECIFICATION.
Improvements in or relating to Pneumatic Tyres..
I, GEORGE HOOKHAM, of 7 & 8, New Bartholomew Street, Birmingham, Manu⚫
facturer, do hereby declare the nature of this invention to be as follows:-
.
The object of my improvements is to introduce between the rim and the pneu-
matic tyre a cushion on which the pneumatic tyre rests; and thus intercept to
a greater extent the short vibrations that are at present transmitted to the
rim, and absorb work done by the rider. I prefer this cushion to take the
form of a second pneumatic tyre, which may be made permanently joined to
the outside tyre, the two forming in section a sort of figure of eight, with a
flat band of canvass at the junction. The canvass is pierced with a hole, so
that the two are in pneumatic connection, or a valve may be used, so that, if
desired, the pressure in the outer tyre may be made to exceed that in the inner.
Otherwise, I may make the rim larger in section, and fasten to its edges a
band of leather or canvass, or indiarubber into which the tyre sinks, and
which takes the pressure at the tread.
Dated this 14th day of September 1899.
.Improvements in or relating to Pneumatic Tyres.
I, GEORGE HOOKкHẠM, Engineer, of 7 and 8, New Bartholomew Street, in the
City of Birmingham, 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 improvements in pneumatic tyres, and has for its
object to prevent the transmission of vibrations to the machine and rider which,
in the ordinary pneumatic tyre, as at present constructed, are so transmitted,
and cause a loss of energy, and consequent slowing of the tyre.
My invention consists in introducing between the rim and the pneumatic
tyre, which comes in contact with the road, a pneumatic cushion on which the
outer pneumatic tyre rests, the pneumatic cushion being inflated preferably to a
less pressure than the outer pneumatic tyre. This I find intercepts, to a
greater extent than is the case with tyres as at present constructed, the short
vibrations which are produced by the smaller unevennesses of the road. At
present these are transmitted to the rim, and their energy thereby dissipated.
It will be observed that if these vibrations can be prevented reaching the
rim, and taken up in the pneumatic tyre, their energy will be utilised, and
at the same time the tyre will be much smoother to ride upon.
Referring now to the, accompanying sheet of drawings.-
Figure 1 shows a section of my improved tyre, mounted on a rim and inflated.
071

page_text: Figure 2 shows a side sectional elevation, showing the means for inflating
the inner tube D.lying next to the tread of the tyre.
In carrying my invention into effect according to one modification, as illus-
trated I provide a rim A having inturned edges B, which engage with the
hooked edges of an arched cover C in a well known manner. I provide three
inner tubes for this tyre, one of them, D, next to the tread, has an outer thin
and flexible casing of canvas or fabric. Along the inner side of this tubular
ring provide a canvas strip E, which is secured to the tube D by cement
or other suitable means. This strip E is provided with eyelets round its edge
next to the rim bottom. These eyelets hook on to a series of hooks placed
round the centre of the rim bottom. At one part of the rim as shewn in
Figure 2 I provide a hole through which a valve stem F passes. This valve
stem is connected inside the rim with a rubber tube G, which in its turn
connects with a suitable branch tube H, secured to the inner tube D. The
valve stem F serves for inflation of the tube D, and as the rubber tube G,
connecting the stem F and the branch H lies at an angle, the movements of
the tyre and the inner tube 1) towards the rim will not cause damage to the
air inlet tube. Between the inner tube D and the rim place two supple-
mentary inner tubes I. These are very flexible, and they are protected by
thin canvas strips at the points where they may come in contact with the
hooks. The inner tubes, I are provided with suitable inflation tubes J, which
are connected by nipples K to a junction pipe L. The inner tubes I are both
inflated to the same pressure by means of the usual valve attached to the
pipe L. In Figure 2 the canvas strip E is shewn interrupted at the place
where the inflation pipe G passes between the tubes I, for the inflation of the
main inner tube D. The two tubes I should be inflated to a somewhat less
pressure than the tube D, the smaller vibrations being transmitted resiliently
to the tyres I.
It will be obvious that my invention may be carried out by the use of two
tubes instead of three, the tube D remaining as illustrated, but the two tubes I
being replaced by a single tube. In this case the inner tube D would be
secured in position in a somewhat different manner, preferably by side strips
of canvas or the like, brought down and tucked under the locking edges of the
cover at B, and a tubular passage would require to be provided through the
single cushioning tyre I, through which the inflation pipe for the inner tube D
would be carried.
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. A pneumatic tyre having two or more tubes mounted on one another,
and encased in a restraining cover, substantially as and for the purpose described.
2. A pneumatic tyre having two cushioning pneumatic tubes supporting a
pneumatic tube next to the tread, substantially as and for the purpose described.
3. A pneumatic tyre having one or more cushioning pneumatic tubes sup-
porting a pneumatic tube next to the tread, the latter being adapted to contain
air at a higher pressure than the former, substantially as and for the purpose
described.
4. The improved pneumatic tyre hereinbefore described with reference to
the accompanying drawings.
Dated this 16th day of July 1900.
MARKS & CLERK,
London, W.C., 13, Temple Street, Birmingham, and 25, Cross Street,
Manchester, Agents.