Improvements in Pneumatic Tires.
Year: 1897

page_text: Date of Application, 31st Aug., 1897-Accepted, 30th Oct.,
1897
Improvements in Pneumatic Tires.
I, EDWIN GEORGE VAN ZANDT,, of 721 Olive Street, in the City of St. Louis,
State of Missouri, United States of America, Gentleman, 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, and
illustrated in the accompanying drawings, wherein :-
-
Figure 1 is a cross-sectional view of a tire embodying my invention, showing
the same deflated, in full lines, and the shape the tire assumes when inflated, in
dotted lines;
Figure 2 is a similar view, showing in full lines the position the tire assumes
when inflated;
Figure 3 illustrates a slightly modified form of tire; and
Figure 4 illustrates the position the tire assumes should the same be punctured
so as to permit the compressed air to escape.
This invention relates to a new and useful improvement in tires for vehicles,
and, particularly, to that class wherein air is introduced under pressure to
maintain the shape of the tire, and also afford a medium of support for the walls
of the tire, and give resiliency to the same.
The objects of the invention are to so construct a tire that it will not slip later-
ally when in contact with wet or slippery surfaces; to increase the traction
qualities of tires of this class; to utilize the contained air to the best possible
advantage; to so construct the tread that it will not pick up and throw mud, etc.;
to afford a firm contact between the base of the tire and the concavity of the rim
in which it is seated, whereby, creeping and displacement are not liable to occur;
and, finally, to construct a tire having the above qualifications in a simple, cheap,
and durable manner.
With the above objects in view, the invention consists in constructing a hollow
tire, the material of which it is made being preferably rubber, reinforced if desired
by fabric, said tire having a narrow or pointed tread, and provided with concavities
or recurved portions in its sides, which, when the tire is sustaining a weight, will
cause the side walls of the tire to move inwardly toward each other, taking the
point or points of resiliency away from the point of contact with the ground, and
locating them between the point of contact with the ground and the point of
pport of the tire, preferably within the lines of pressure.
Another feature resides in the novel construction of the tire, as will here-in-
after be fully described, and, afterwards, pointed out in the claims.
In the drawings, A indicates the rim, of any ordinary or approved form, the
same having as usual, a peripheral concaved seat for the tire.
B indicates the base of the tire, which, when deflated, is described from a circle
of less radius than the concavity of the seat in the wheel rim. The object of this
is to accommodate the change of form or shape of the tire when air is introduced
under pressure.
The side walls C of the tire, near the base, are inclined toward each other at

page_text: their outer ends, and preferably curved, so that, in action, they move toward
each other, compressing the confined air between them.
D indicates recurved portions in the sides of the tire, which form oppositely-
disposed curved side walls, located almost entirely within the lines of pressure,
as I will term them, which are lines from point of contact of tread to extreme
lateral points of support, as indicated by dotted lines in Figure 2. These recurved
portions of the side walls will move toward each other when pressure is placed on
the tread, as is obvious, and be compressed, at the same time, acting against the
confined pressure of air within.
E indicates side walls leading from the outer extremities of the recurved
portions D, and preferably reversely curved with relation thereto. At the
junction or apex of walls E, is formed the tread F, which, as shown, is pointed,
but it may be flattened somewhat, if desired as is obvious.
The action of the side walls of this tire when pressure is placed on the tread, is
obvious. The walls E, where they join the recurved walls D, tend to spread.
The tendency of the walls 1) is to counteract this, however, and, by reason of the
pressure of walls C, the walls D and C move inwardly. These opposing tendencies,
each having a certain freedom of movement, renders the tire most sensitive and
resilient at points between the tread and support.
The comparatively large surface area of wall 13 holds the tire firmly to its seat,
but it may be found desirable, in some instances, to use cement as a permanent
binding medium which will be active when the tire is deflated as well as when it
is inflated.
The lines of the tire, except the recurved walls D, are almost in line with the
lines of pressure, which is advantageous in that said walls may be made com-
paratively light to carry required loads. The wedge-shape of the tire is also
advantageous, because it has been found by experience that a tire constructed as
shown in the drawings is not liable to pick up and throw mud, etc., and impossible
to side slip.
Suitable fabric is introduced to strengthen the rubber, if desired, as is well
understood.
In Figures 3 and 4 I have illustrated a slightly different form of tyre, in which
a flattened tread F¹ is used, and the recurved side walls D' extend the entire
distance from the base wall B to the tread. Should a tire of this construction
become punctured, or in any manner become deflated in use, the parts will assume
the position shown in Figure 4 at the ground contact point, and thus save the wheel
rim.
I am aware that many minor changes in the construction, arrangement, and
combination of the several parts of my invention can be made and substituted
for those herein shown and described, without, in the least, departing from the
nature and principle of my invention.
Having now particularly described and ascertained the nature of my invention,
and in what manner the same is to be performed, I declare that what I claim is:
1. A pneumatic tire formed with a single opening, the sides of which are
adapted to move inwardly toward each other, when the tire strikes an obstacle,
or when an abnormal pressure is brought to bear upon the outside of the tread;
substantially as described.
2. A pneumatic tire, the sides of which are concaved, the lines of said concavities
beginning at a point at or near the tread, and ending at or near the rim to which
the tire is attached; substantially as described.
3. A pneumatic tire formed with a thickened tread, and reduced concaved sides,
whereby, when an abnormal pressure is brought to bear upon the outside of said
tread, the sides will move inwardly toward each other; substantially as described.
4. A pneumatic tire formed with reduced cancaved sides, and strengthening
fabric imbedded in said reduced sides; substantially as described.
5. A tire composed of a base wall, a tread, and oppositely recurved portions D

page_text: located almost entirely within lines drawn from the tread to the lateral extremities
of the base wall; substantially as described.
Par
0
For the Applicant,
PHILIP M. JUSTICE,
London, Chartered Patent Agent.