Improvements in and relating to Elastic Tyres for Wheels.
Year: 1895

page_text: Date of Application, 12th Nov., 1895
Complete Specification Left, 10th Aug., 1896-Accepted, 3rd Oct., 1896
PROVISIONAL SPECIFICATION.
Improvements in and relating to Elastic Tyres for Wheels.
I, PIERRE AMBJORN, COMTE DE SPARRE, of 16, Place de la Madeleine, Paris,
in the Republic of France, Civil Engineer, do hereby declare the nature of this
invention to be as follows:-
My invention relates to elastic tyres for the wheels of bicycles, tricycles and
other velocipedes or vehicles, the object of my invention being to provide
improved means for rendering tyres elastic and yielding without the use of an
inflated air chamber.
According to my invention the tyre is moulded of an arch or channel shape the
extremities or edges of which are designed to lie upon the wheel rim. The tread
portion of the tyre is formed with a projecting rib or flange which is narrower at
its point of contact with the arch than the distance between the inner sides of the
arch at the extremities, the said rib or flange being preferably of the same width or
slightly narrower at its base where it joins the arch part of the tyre than at the
surface which comes into contact with the ground.
With this construction the weight upon the tyre is transmitted to the arch
through the narrow tread so that the said arch is pushed back more or less
towards the rim.
In practice I provide the wheel rim with side flanges to retain the tyre in its
proper position upon the rim, and I also find it advantageous to make the wheel
rim with a recess or groove around its periphery into which the tyre can enter
when pushed back.
Dated thie 19th day of November 1895
COMPLETE SPECIFICATION.
Improvements in and relating to Elastic Tyres for Wheels.
I, PIERRE AMBJORN COMTE DE SPARRE, of 16 Place de la Madeleine, Paris,
in the Republic of France, Civil 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 :-
My invention relates to elastic tyres for the wheels of bicycles, tricycles and
other velocipedes or vehicles, the object of my invention being to provide
improved means for rendering tyres elastic and yielding without the use of an
inflated air chamber.
According to my invention the tyre is moulded or formed of a channel shape the
extremities or edges of which are designed to lie upon the wheel rim. The tread
portion of the tyre is formed with a projecting rib or flange which is narrower at
its point of contact with the channel than the distance between the inner sides of
the channel at the extremities.
With this construction the weight upon the tyre is transmitted to the channelled
portion through the narrow tread so that the said channelled portion is pushed
back more or less towards the rim.

page_text: In practice I provide the wheel rim with side flanges to retain the tyre in its
proper position upon the rim, and I also find it advantageous to make the wheel
rim with a recess or groove around its periphery into which the tyre can enter
when pushed back.
To enable my invention to be fully, understood. I will describe it by reference to
tho accompanying drawing, in which:-
Figure 1 is a transverse section of an elastic tyre constructed according to my
invention and fitted to the rim of a wheel, the tyre being in its normal condition,
that is to say, having the shapelin cross section which at assumes when iti is not
supporting a load.
Figure 2 is a similar view shewing the tyre of the shape which it may assume
when supporting a load.
a is the tyre of rubber or other similar material, the said tyre being made, as
shewn in Figure 1, of a chanuel shape; the edges bb of the said channel, portion
-are designed to rest upon the wheel rim A. c.is, the rib or. flange forming, she
T
tread portion of the tyre.
The distance d d where tlie rib or flange e comes in contact with the channel
portion of the tyre is, as shewn, madenarrower than the distance between the
edges of the channel. In some cases, however, when the tyre has to support a
heavy load such as a carriage I make the distance did approximately equal to the
distance between the said edges b. b.
ee are the side flanges designed, to retain the tyre in its proper position upon the
rim, and is the recess or groove formed around the periphery of the rim.
In order to give the extremities or edges b biof the tyre the required. rigidity, to
prevent them from leaving the side flauges eofthe rim l mould the rubber tyre
with a strip or strips of canvas.or other suitable fabricifluted or folded backwards
and forwards as shewn at gg.
The shape of the rim and tyre shown in the drawing is that which I have, ſound
to be the most suitable, but it will be obvious that I can vary the same, more.or
less and still obtain similar results to those herein before described.
With this construction it will be obvious, as above described; that when a loµd
is put upon the tyre the force is transmitted through the narrow part d d of the
tread c to the channel portion so that the said channel portion is bulged more or
less inwards according to the amount of the load as shewn in Figure 2. This
inward ‘bulging of the tyre, causes the edges! bb of the same to press outwards
against the side flanges ee of the rim A and the distance d d becomes slightly less
than when the tyre is not supporting a load.
Having now particularly described and ascertained the nature of my said inver-
tion and, in what manner. the same is to, be performed 1,declare that what I
claim is: :―
1. A-wheel tyre moulded or formed to a channel shape and provided with a
peripheral-rib or flange the base of which is narrower than the distance between
the inside edges of the chaunel, the said rib or flange boing adapted to transmit
pressure to the chanuel portion of the tyre in such a manner that the said portion
will be bulged inwards substantially.as:described.
2. The combination with an elastic tyre of the kind, described in the, preceding
claiming clause of a strip or strips of canvas or other,, suitable, fabric fluted or
folded backwards and forwards in the edges of the channel,, substantially as
described.
63. The manufacture and use of the improved elasticatyre for wheels hereinbefore
described.and illustrated in the accompanying drawing.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.