Improvements in or relating to Wheel Tires.
Year: 1893

page_text: Date of Application, 17th Apr., 1893-Accepted, 20th May, 1893
COMPLETE SPECIFICATION.
Improvements in or relating to Wheel Tires.
A communication from JOHN THOMPSON SMITH, of Bridgeport, State of
Connecticut, United States of America, Shipwright, and ARTHUR HERBERT
SMITH, of New York, State of New York, United States of America,
Attorney at Law.
I, ALFRED JULIUS BOULT, of 323 High Holborn, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
The invention has for its object improvements in tires that are used for bicycle
or carriage wheels, and such other wheels as are calling for an encircling band or
hoop possessed of a certain softness and elasticity. It is therefore designed to
provide a tire of simple construction and graceful outline combining these qualities
in a superior degree, and commendable as well for its lightness, durability and low
cost of manufacture.
The improved tire resulting from this invention consists of a hoop or band of
elastic material formed in two parts which are called respectively the crown and
the webbing. These parts are at right angles, one to the other, the webbing pro-
jecting inwardly from the crown. Both are oblong in cross-section and made to be
partly inclosed in a wheel-rim specially designed to receive and support them. The
webbing has notches or indentations in its margin, which presents an endless series
of points or disconnected sections, all bearing upon the periphery of the wheel but
adapted to act freely and independently of one another. Depressions are likewise
provided in the under side of the crown to isolate its edges from the webbing and
allow them an independent action of their own, which they exert upon opposite
sides of the wheel. The various sections of the tire are thus adapted to work
separately, though conjointly, with the result that both easier compression and
quicker recoil are secured, together with several other advantages hereinafter set
forth in detail.
Referring to the accompanying drawings, which form part of this Specification,―
Figure 1 is a side elevation, on a small scale, of the tire as it appears when
removed from the wheel;
Figure 2, a similar view of the wheel with the tire applied thereto, part being
broken away to show the notches in the tire's margin;
Figure 3, a cross-section of a small portion of a full-sized tire:
Figure 4, a like view of a corresponding portion of the wheel's rim;
Figure 5, a broken side elevation of part of a full-sized wheel and tire, one side
of the rim being removed to show the webbing and notches therein; and
Figure 6, a transverse section of part of the tire and its enclosing rim.
Similar parts are indicated by similar letters of reference throughout all the
views.
The whole tire, as shown at Figure 1, is preferably made of vulcanized rubber,
though cork or other elastic material may also enter into its composition. This
tire may be moulded or otherwise formed in a single piece, but it comprises two
distinct parts, which are respectively termed the webbing and the crown, and
designated by the letters A and B. A, the webbing, forms the inner part, while
B, the crown, constitutes the outer part. Both are oblong in cross-section and they
are set at right angles one to the other, the webbing running inwardly from the
central part of the crown, so that the tire attains its greatest thickness and width
at the points where they meet. By preference, the webbing is made slightly
tapering toward the edge, which is rounded. The top or face of the crown is also
:

page_text: rounded, being semi-circular in form and ending in overhanging lobes or flanges b,
which project outwardly a uniform distance from each side of the webbing.
In the edge or margin of the webbing are formed notches or indentations, C.
These may vary in depth and width according to the size or dimensions of the tire
and the firmness of the material of which it is made. They extend clear through
the margin of the webbing and are located at regular but more or less close
intervals, according to circumstances. These notches are for the purpose of
dividing the margin in a convenient number of at least partly-disconnected sections
or points which may contract and expand independently of one another.
Depressions D, somewhat analogous to the notches C, but running longitudinally
instead of crosswise, are provided in the under side of the crown at the points
where the lobes 6 curve up toward the webbing. They serve to isolate the edges
of the crown from the webbing and secure for them also separate or independent
compression and dilatation.
E represents a wheel to which the above described tire is applicable. This
wheel is of the usual construction, except the rim, which is curved so as to form
three grooves or channels, F, F1, F2, adapted to receive and support, respectively,
the projecting edges of the webbing and crown composing the tire. The points.or
disconnected sections of the webbing, it will be seen, all rest in the central and
deepest groove, while the tips of the lobes find a bearing in the side channels, but
no part of the rim reaches up into the notches nor into the lateral depressions.
The crown is made to project out a sufficient distance from the rim to allow for full
compression outside of it and avoid the denting of the rim on stones and like
objects. On the other hand, the rim is made a trifle wider than the crown and
slightly curved up to inclose the lobes and provide for their expansion, so that the
tire may not be cut at the edges, nor spring out of place, but will be drawn firmly
on and cling to the rim, when under compression, and expand without binding, when
the pressure is off.
The spokes G, extending from the hub to the periphery of the wheel, may be
arranged in various ways, but a most practical arrangement, it is conceived, is to
run up part of them to the center of the rim, right under the webbing, and the
remainder to the sides on which the lobes of the crown rest.
It will be observed that a tire constructed on the foregoing lines and applied as
directed efficiently meets the requirements of velocipedes and other vehicles of the
class above referred to. In the first place, it is very light, because stripped of
unnecessary appendages and freed from everything that merely adds to bulk and
weight. While it is devoid of all useless features and adjuncts it is nevertheless
possessed of much strength, owing to its peculiar shape, which presents the greatest
thickness where the pressure is always greatest, that is to say from the top of the
crown to the inner edge of the webbing. In this respect it is believed to be
superior to either the ordinary cushion or the pneumatic tire, because adapted to
stand rougher service and not liable to be injured or irreparably damaged by
punctures or breaks. It therefore excels in durability. Another remarkable
feature of such a tire is the high degree of elasticity which it derives from and is
the immediate result of the improved mode of construction hereinbefore set forth.
The tire being provided with longitudinal depressions or recesses in the under side
of its crown and a large number of notches across the margin of its webbing, it
becomes very sensitive to pressure and quite springy, the lobes at the surface and
the notched edge at the bottom affording ample facilities for the compression, con-
traction, or expansion, wherever it takes place. Each lobe being practically
isolated from the body of the tire and each section of the webbing's margin discon-
nected from the neighbouring ones, these parts act and are acted upon freely and
independently, without strain upon or hinderance from the others. No part of the
tire is impeded in its contraction or expansion, and each performs its function in
quicker time than would be possible otherwise. But while there is separate and
independent contraction and expansion there is also joint action, since the discon-
nected parts of the webbing and the two lobes of the crown are subject to the same

page_text: influences and portions thereof are acting as well as being acted upon together
Hence more life and resiliency and a quicker rebound of the tire after compression.
This joint action of the upper and lower parts assisting each other in producing
elasticity imparts a sort of automatic movement to the tire which makes itself
felt upon the wheel and somewhat favours its speed. The tire, besides, is as
soft and easy as the hollow ones, and yet it need not be inflated nor does it
call for specially prepared material and an expensive mode of construction. A
firmer quality of rubber may be used for it than for tires of the latter class,
with the result that it will wear better, ride more easily on rough ground, and
be unaffected by moisture and dirt. In short, it is believed to have all the
advantages of the ordinary cushion and pneumatic tires, without the drawbacks
of either.
The above described construction admits of several modifications. For instance,
perforations in the body of the webbing may take the place of the notches at the
margin thereof, although they would be less effective unless they were used in
connection with such notches. Similarly, perforations may be had in the center of
the tire or in its upper part, but this mode of construction is not considered very
practical, because such perforations would be exposed to view and remain unpro-
tected. They would be liable to fill with dirt or foreign matter and would thus
partly destroy the usefulness of the tire and mar its appearance. Lastly, indenta-
tions or notches may be made in the lower edge of the crown as well as in the
margin of the webbing, if desired.
Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondents and in what manner the
same is to be performed, I declare that what I claim is :-
1. An elastic tire comprising a flanged crown and a webbing provided with
transverse openings, substantially as set forth.
2. An elastic tire comprising a crown and an oblong webbing having marginal
disconnected sections, substantially as set forth.
3. An elastic tire comprising a webbing and a flanged crown forming longitudinal
depressions on each side of the webbing, substantially as set forth.
4. The combination, in an elastic tire, of a notched webbing, a crown thereon,
and lobes or flanges projecting from said crown, substantially as set forth.
5. The general combined arrangement and construction of parts forming the
improved tire, substantially as set forth.
Dated this 17th day of April 1893.
W. P. THOMPSON & BOULT,
Of London, Nottingham, Manchester, and Liverpool,
Agents for the Applicant.