Improvements in Pneumatie Tyres for the Wheels of Cycles and other Vehicles.
Year: 1898

page_text: Date of Application, 6th Dec., 1898-Accepted, 28th Jan., 1899
[Communicated from abroad by VEREINIGTE GUMMIWAAREN-FABRIKEN HARBURG-
WIEN vormals Menier J. N. REITHOFFER, of Harburg a/Elbe, in the Empire
of Germany.]
Improvements in Pneumatie Tyres for the Wheels of Cycles and other
Vehicles.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, 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 a novel pneumatic tyre for the wheels of cycles and
other vehicles, which is capable of use with wheel rims or fellies of various forms;
that is to say the tyre is so formed that, on the one hand, the same tyre may be
used upon and will fit equally well rims of different diameters and sections, and
on the other hand it does not require to be held upon such rim by any separate
or additional means such as cement, wires, enlarged or beaded edges or the like.
A pneumatic tyre manufactured in accordance with this invention may be so
reduced in diameter by inflation, that the same tyre whether fitted upon a 30 inch,
28 inch or 26 inch rim, will grip the rim tightly and be retained thereon merely
owing to the internal air pressure, contrary to what has been the case with
pneumatic tyres as hitherto constructed which must correspond in diameter to
the rim to which they are to be fitted; that is to say, a 30 inch tyre must be used
for a 30 inch rim, a 28 inch tyre for a 28 inch rim, and so forth. This inconveni-
ence has been felt to be so great, that in recent years it has become the practice
to build cycles with front and rear wheels of the same diameter either 26, 28 or
30 inches, although experience had shewn that it was preferable to have the front
wheel of a roadster machine larger than the hind wheel, and the front wheel of a
racing machine smaller than the hind wheel.
A pneumatic tyre in accordance with this invention may be quite loosely laid
upon the wheel rim, and becomes tight upon such rim as a result of the reduction
of its diameter which takes place upon inflation, so that the tyre cannot slip over
the edges of the rim upon which it exerts a radial pressure so that wooden rims
may advantageously be employed.
The characteristic feature of this novel pneumatic tyre resides in the fact that,
not only is it impossible for it to stretch in the direction of the axis of its bore
or air space, but on the contrary is caused to contract in a radial direction upon
inflation. This result is obtained in accordance with this invention, by forming
the tyre from a piece of fabric which, after it has been saturated or coated with
rubber and cut diagonally to the threads in the usual manner, is fully stretched
out in the direction of its length and treated and vulcanized whilst maintained
in this stretched condition. During this treatment the fabric which has been
prepared with rubber as above stated, may be either in the form of a flat band
or made up into tubular shape.

page_text: As a result of this treatment of the tyre fabric, the previously quadrilateral or
rectangular spaces between the warp and weft threads are made permanently of
an elongated rhomboidal or lozenge shape, the very acute angles of which lie in
the longitudinal direction whilst the very oblique or almost flat angles lie in the
transverse direction of the tyre. The tyre has consequently attained its extreme
limit of extensibility in the direction of the axis of its bore or internal space,
whilst it is capable of very considerable expansion in the direction of its width,
and consequently when it expands upon being subjected to internal pressure, the
tyre is forced to contract in the radial direction in proportion as more air is forced
into it.
When it is formed into a tube, this is cut, in order to manufacture a pneumatic
tyre somewhat longer than the circumference of the largest rim upon which the
tyre is intended to be used, so that it may be laid easily upon such rim. When
this tube of fabric (which is provided with the usual rubber air-tube with inflating
valve) is inflated upon the rim, it will, as above explained, increase in cross-
section and decrease in circumference as a tyre, owing to the inherent property
of the material which has been permanently stretched to and vulcanised in its
extreme condition of extensibility in the direction of the axis of the bore or
internal chamber of the tyre, until the tyre is tightly pressed against the wheel
rim and so securely held in the latter whatever the cross-section of its groove,
without its being necessary to assist in securing it by any special or additional
means.
If an outer cover or tread is to be made for forming a tyre in accordance with
this invention, the fabric is vulcanised in a fully stretched condition upon a drum,
the diameter of which is greater by a suitable amount than the rim, upon which
the cover is laid in the same manner as the tube above described over the air tub
proper of the ordinary kind and secured by lacing or buttoning or in any other
suitable manner, so that when the inner tube is inflated the cover will stretch
with it and in so doing, be drawn together round the rim, seeing that the cover
is inextensible in the direction of the circumference of the rim.
1
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondents, I declare that what I claim is :-
1. Pneumatic tyres for cycles and other vehicles characterised by an insertion
fabric cut diagonally and vulcanised in a fully stretched condition.
2. A process for the manufacture of pneumatic tyres for rims or fellies of
various sizes in accordance with Claim 1, characterised by the fact that the
diagonally cut insertion fabric which is employed is stretched to its utmost
capacity in its longitudinal direction before being treated and treated and
vulcanized in this stretched condition.
Dated this 6th day of December 1898.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.