Improvements in Tyres for Wheels.
Year: 1892

page_text: Date of Application, 28th Sept., 1892-Accepted, 5th Nov., 1892
COMPLETE SPECIFICATION.
Improvements in Tyres for Wheels.
I, ROGER, BARON OF MAUNI, of Croisset, near Dieppedalle, Department of Seine-
Inférieure, France, Inventor, 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 :-
"The new elastic tympan tyre" consists: first, in a film or ribbon, made of some
elastic stuff as india-rubber, which ribbon is drawn and fixed, like a drum's skin,
on the groove of a cycle wheel's rim;-then, in an ordinary rubber tyre, either
hollow or full, which is drawn around the wheel and presses upon the film or
tympan but very slightly; and finally, in an elastic envelope or ribbon, which
surrounds and wraps up the whole.
This new tyre can be fitted on all existing bicyclettes or tricycles, provided the
rims of the wheels be grooved exteriorly, as is most frequently the case.
No sort of glue or paste is used in fixing the tympan tyre on the wheel. When
adapting this new tyre to an old machine, the existing remnants of paste or glue
ought to be well scratched away, and the edges of the rim polished and greased with
tallow or some other substance.
The ribbon which we use is made of elastic india-rubber sheet, with a hem on
both sides, the said hem fitted with a cloth band, so as to protect the rubber sheet
from being cut by the edges of the rim.
The cloth band is pasted and stitched on the tympan's hem, so as to prevent also
any rubbing or any tension inside of the hem. Thus only the middle part of
the ribbon remains elastic and extensible.
The ribbon is stitched or laced around the wheel's rim, the cloth hem resting
on the rim's edge, and the rubber sheet or tympan, which is the essential part
of the system, being strongly and equally tended on the rim's groove. The required
degree of tension has to be deducted from experience, as will be seen below.
The tyre, either hollow or full, which has to be laid on the tympan, ought
to be somewhat thinner than would have been convenient under the ordinary
system, as it must, when pressed upon, freely enter the groove till it forces the
tympan against the bottom of the said groove, the whole resistance to pression
being furnished by the elastic strength of the tympan and not by any straitness of
the groove.
The thickness and tension both of the tympan and of the tyre have to be regulated
in such a manner, that, the cyclist being on his saddle and riding with all his weight,
the tympan be drawn near to the bottom of the rim's groove, but without touching it
except when jolting heavily, and the tyre may not get sunk in the groove so deeply
as to allow the rim's edge to strike the soil.
Last comes the wrapper or mantle, whose use is to prevent the tyre's slipping
away or the introduction of dust or any prejudicial rubbish between the tyre and
the tympan. That mantle is, as well as the tympan, an elastic ribbon, but with the
following differences:-It ought not to be strongly tended, but just enough to
prevent the tyre's rolling or slipping and to avoid any plaiting or wrinkling of the
mantle next to it's point of contact with the soil;-further, it's middle part, which
has to touch the ground, ought to be strengthened by some ccating, in order to
prevent the too rapid wearing of the said mantle; and finally, it must be stitched
or sewed close together on the inward part of the rim, thus covering the whole system
and offering a clean appearance.
The new tympan tyre is superior, as for elasticity and cheapness, to any pneumatic
tyres; it is not heavier, and fears no bursting nor piercing, as it does not require
any impermeability.

page_text: 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:
1st and only: The obtaining the elasticity and easy rolling of cycle wheels or
other wheels by means of an elastic film tended on the exterior groove of the
wheel's rim and supporting the tyre.
Dated this Twenty-sixth day of September, One thousand eight hundred and
ninety-two.
BARON DE MAUNI.