An Improvement in the Method of Attaching Pneumatic Tyres to the Wheels of Cycles and other Vehicles.
Year: 1892

page_text: Date of Application, 26th Nov., 1892
Complete Specification Left, 20th Sept., 1893-Accepted, 21st Oct., 1893
PROVISIONAL SPECIFICATION.
An Improvement in the Method of Attaching Pneumatic Tyres to
the Wheels of Cycles and other Vehicles.
I, JOHN HUSTON STEWART B.Sc. B.A. of No. 25 Marlborough Road in the
County of Dublin Professor of Experimental Physics in University College,
Dublin, a Fellow of the Royal University of Ireland, do hereby declare the nature
of this invention to be as follows:-
The invention is applicable to tyres containing compressed air, that is air at
more than atmospheric pressure. According to my invention the pressure of the
air inside the tyre causes the side-flaps of the outer covering to firmly grip the
outside of the wheel rim, so that it is impossible for the tyre to come off or get
displaced so long as the inside air is kept at sufficient pressure. If however, the
valve leading to the air chamber inside the inner tube of the tyre be opened, and
the air released, the outer cover may be at once taken off and the inner tube
exposed. Each side flap is strong and inextensible, containing some such structure
as a band or wire of metal or other suitable material which forms a circle whose
diameter is less than that of the outer edge of the wheel rim. It is thus impossible
for the flap as a whole to come over the edge of the rim. The pressure inside the
tyre being the same throughout, the curvature and dimensions of the tyre are
necessarily the same everywhere and the side flaps take up a symmetrical position
outside the rim, which increase of pressure causes them to retain more firmly. As
a wheel may be passed through a hoop of less circumference provided that the
latter be made oval, so when the tyre is deflated the flaps can be depressed at
one side of the wheel so as to enable them to pass over the rim at the other side,
i.e., at the opposite end of a diameter.
Such tyres as this invention is applicable to usually consist of an air-chamber
protected by an outer cover of thicker rubber, the latter being strengthened on the
inside by a canvas lining. It may however prove applicable to tyres of a different
construction.
.
There are many advantages to be gained by causing a tyre to adhere
(i.e. keeping it firmly attached) to the outside of a wheel rim by the pressure of
the internal air alone.
Nombor 1900
J. H. STEWART.
COMPLETE SPECIFICATION.
An Improvement in the Method of Attaching Pneumatic Tyres to
the Wheels of Cycles and other Vehicles.
I, JOHN HUSTON STEWART, B.Sc., B.A., of No. 26 Leeson Park (formerly of
No. 25 Marlborough Road), in the County of Dublin, Professor of Experimental
Physics in University College, Dublin, a Fellow of the Royal University of
Ireland, 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 :-
66
My invention has reference to that class of tyre now generally known as
pneumatic" wherein a hollow tube filled with air or other fluid under pressure
covered by a restraining medium is detachably held to the rim or felloe of the
wheel, and it consists in providing means whereby the tyre is held to the outer or
convex surface of the wheel rim by forces solely derived from the pressure of the
Finternal air

page_text: The accompanying drawing, which shows a cross-sectional view of a velocipede
wheel and tyre, illustrates a method of carrying my invention into effect.
A, is the usual internal or inflatable tube which is provided with customary or
suitable valvular apparatus for charging and discharging. B, is the metallic rim
of crescent or other suitable section preferably deeper than is usually employed so
that its edges b, project beyond the centre c, of the curves b, 2, 61 when the
tube A is inflated. C, is the outer casing or tread, arch-shaped in cross-section,
and composed of rubber or its equivalent in the usual way. D, is one of the spokes
of the wheel.
The outer casing or tread C, is lined with strong canvas or its equivalent,
which is continued in side flaps or extensions d, of a strong and inextensible
nature which contain at each of their edges a hoop or annulus of wire or its
equivalent e, which forms a circle whose diameter is less than that of the circles
formed by the outer edges b, b', of the wheel rim or felloe. As the tyre is inflated,
the internal air pressure being the same throughout, the curvature and dimensions
of the tyre if properly and symmetrically constructed are necessarily identical in all
places, and the side flaps or extensions take up a symmetrical position as shown,
outside the rim or felloe which they retain more firmly as the pressure is increased.
If found advisable the edges of the side flaps may bed into depressions or grooves
on the outside of the wheel rim or felloe.
While the tyre is inflated it is impossible for either flap or extension as a whole
to pass over the edge of the rim or felloe, but as a wheel may be passed through a
hoop of less circumference provided that the latter be made oval, so when the tyre
is deflated the flaps can be depressed at one side of the wheel so as to enable them
to pass over the rim at the other side-that is to say at the opposite end of a
diameter.
In order to prevent lateral bulging out of the side flaps at the part of the tyre
in contact with the ground and to prevent the admission of foreign substances I
sometimes use two or other side flaps originating at b and b¹ and lying inside the
wheel rim that is to say on its concave side. These latter flaps may or may not be
united by a structure lying between the air tube and the wheel rim.
In some cases one edge of the outer cover may be permanently fixed to the
wheel-rim, and the other one only made with the adjustable side flap or flaps as
described above.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a pneumatic tyre, securing the outer casing or tread to the outer or convex
surface of the wheel rim or felloe by forces solely derived from the pressure of the
internal air substantially as set forth.
2. In a pneumatic tyre wherein the outer casing or tread is detachably secured to
the outer or convex surface of a wheel rim or felloe by means of forces solely
derived from the pressure of the internal air, flaps or extensions such as d,
provided at each of their edges with a hoop or annulus of wire such as e,
substantially as set forth.
3. In a pneumatic tyre wherein the outer casing or tread is detachably secured
to the outer or convex surface of the wheel rim or felloe by means of forces solely
derived from the pressure of the internal air, the combination, with an inflatable
tube and restraining medium, of a rim preferably with deepened edges and an outer
casing or tread having flaps or extensions each provided with a hoop or annulus of
wire of less diameter than such rim edges or felloe and together forming the
means of securing the tyre to the wheel substantially as set forth.
ሰስ |
Ca
1000
A. F. SPOONER,
124, Chancery Lane, W.C., Agent for the Applicant.