A New or Improved Cover or Protector for the Air-tubes of Pneumatic Tyres.
Year: 1899

page_text: Date of Application, 8th Dec., 1899-Accepted, 13th Jan., 1900
COMPLETE SPECIFICATION.
A New or Improved Cover or Protector for the Air-tubes of
Pneumatic Tyres.
We, FRANZ CHRIST, Agent, Dr. CARL FLASCHAR, Advocate, and HERMANN
SCHEFFER, Factory Director, all of Mährisch-Trübau, in the Empire of Austria,
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 object of the present invention is a novel cover or protector for the air-
tubes of pneumatic tyres for the wheels of cycles, automotors and the like,
affording the said air tube a very great protection against damage and punctures
in consequence of the penetration of sharp or pointed objects, and also against
becoming loose and bursting. This new cover or protector is composed of a very
strong and close fabric and the air tube is covered with a strong layer of the said
fabric.
In the annexed drawing the invention is shown in various forms of construction,
as examples;
Fig. 1 is a section through a single cover or protector strengthened by an inner
strip or stiffener on its tread portion.
Fig. 2 is a section through a double cover, the inner strip consisting of one
piece;
Fig. 3 is a section through a double cover, the strip of which consists of three
pieces placed together;
Fig. 4 is a section showing a protector or cover in two parts lying upon one
another on the tread of the tyre.
Fig. 5 represents the effect of a nail or other sharp object on penetration through
a double protector.
The air tube a is put in the known manner into the cover or protector 6 and
fixed with the same by means of the bent over edge of the rim c of the wheel.
This cover is not made as hitherto of vulcanized rubber, but consists of a tightly
woven, very close fabric which is rendered still closer by impregnating and
fulling. A material very suitable for this purpose, is a very closely woven strip
of repeatedly twined rough hemp rendered still more impenetratable by repeated
impregnation and subsequent fulling, but also other close fabrics of resistant
material may be used. For protection against humidity and wear the cover or
protector may be covered with a thin layer of india rubber.
The cover described offers a far better resistance against the penetration of
glass, thorns, nails and the like, than the cover of vulcanized rubber hitherto
used, so that the danger of injuring the air tube or of its bursting is very much
reduced and this cover alone can be used on smooth tracks for racing and the
like.
A further protection practically rendering the air tube absolutely safe against
injury is obtained by placing between the air tube a and the cover b one or more
loose inner strips d1, d2, d3, d4, of the same fabric as the cover, the same being
secured against lateral movement. These strips can be used in different forms,

page_text: Fig. 1 shows a simple form in which the strip d 1 only doubles in thickness
the tread of the cover.
Fig. 2 shows a strip d2 doubling in thickness the whole external surface of the
cover; the said strip consisting of one piece.
Fig. 3 shows a strip d3 doubling the whole outer surface of the cover and con-
sisting of three parts placed together.
Fig. 4 shows two strips d4 increasing by twice the thickness of the side sur-
faces of the cover and by three times the tread thereof. By increasing the
number of the strips in the described or similar manner the cover can fulfil also
the increased requirements of a heavier load.
In order to prevent friction between the different strips or between the cover
and air tube, the surfaces of the said parts in contact with one: another may be
provided with a cover of thin linen or the like.
if a sharp object penetrates the cover it presses against the strip and the latter
is not easily penetrated but gives way and bends with the air tube in its resist-
ance as shown in Fig. 5 thus preventing any injury to the said air-tube.
Practical trials have shown that the protection of the air tubes against injury
by use of this new cover is nearly absolute. Glass for instance easily cutting
right through the hitherto used tyres can scarcely do any injury to the outer
cover of this invention and still less to the strip or air-tube. Nails although they
may have penetrated the outer cover, are rendered harmless as their points are
bent on the strip or the strip with the air tube thereunder gives way, or the nail is
turned off sideways.
.
The weight of the new cover as a double cover, (Fig. 2) is nearly equal to the
weight of the vulcanized rubber covers now in use. The prime cost is not higher
and the elasticity is not inferior to that of the tyres hitherto used.
With these covers the air tube in its actual form may also be entirely dispensed
with when using either the strip in the form d2 (double cover, Fig. 2) at the same
time as an air tube after suitable closing and tightening by india rubber or any
other suitable material, or by entirely dispensing with any strip, the use of the
outer cover thus prepared at the same time also as an air tube. The extraordinary
solidity and impenetrability of the fabric has the result that the protection against
damage and the leakage of air even with the use of only one strip is very great,
but when using a double strip is practically absolute.
Having now particularly described the nature of the said invention, and in
what manner the same is to be performed, we declare that what we claim is:-
A new or improved cover or protector for the air-tubes of pneumatic tyres for
wheels of all kinds consisting of a cover of a very strong and close fabric sur-
rounding the air tube, with or without one or more inner strips of the same fabric,
between the cover and the air tube, for still further increasing the safety, the
whole substantially as described.
Dated this 8th dor of Dacombon 1800
HERBERT HADDAN & Co.,
Agents to Applicants, 18, Buckingham Street, Strand, London.