Improvement in Pneumatic Tires for the Wheels of Vehicles.
Year: 1891

page_text: Date of Application, 7th July, 1891-Accepted, 8th Aug., 1891
COMPLETE SPECIFICATION.
Improvement in Pneumatic Tires for the Wheels of Vehicles.
I, PARDON WILBUR TILLINGHAST, of 435 Potter's Avenue, in Providence,
Rhode Island, United States of America, Draughtsman, 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 :-
Heretofore in the employment of pneumatic tires for the wheels of vehicles; it
has been deemed necessary to employ either special means for fastening the tire to
the rim of the wheel, as by ribs or flaps, or to form the rim with a nearly semi-
circular groove, to receive the inner side of the annular tire; and in this latter case,
the projecting edges of the rim, interfere with the proper yielding action of the
sides of the tire; and it is the object of my invention to dispense with the special
fastening means, and to firmly retain the tire upon a rim having a comparatively
shallow groove, without resorting to the attaching ribs or flaps, as heretofore; and
my invention consists in an annular pneumatic tire made of less interior diameter
than the diameter of the rim of the wheel at the bottom of its shallow holding
groove, and provided with a valved opening for inflating the tire when stretched
upon the rim, and having a yielding inner wall adapted for extension longitudinally
to embrace the groove of the rim; and a non-extensible re-enforcement in the outer
peripheral wall, to prevent the corresponding extension of the outer wall when
subjected to the pressure of inflation, upon the rim of the wheel; and my invention
also consists in the improved construction of the air valve for the tire.
Fig. 1, represents a transverse vertical section of a vehicle wheel having a grooved
rim adapted to receive the pneumatic tire.
Fig. 2, represents a transverse vertical section of the pneumatic tire made smaller
than the groove of the rim.
Fig. 3, represents an enlarged transverse section of the pneumatic tire and the
rim of the wheel, also showing the valve opening for inflating the tire.
Fig. 4, represents an enlarged transverse section of the tire and rim, showing a
modification.
In the accompanying drawings A., Fig. 1, represents the rim of the vehicle wheel,
provided with the shallow holding groove B, in which the tire is to be placed. The
annular pneumatic tire C, Fig. 2, is so formed, that the diametrical distance between
its inner walls b, b, is less than the diameter of the wheel at the bottom of the
groove B, as shown by the dotted lines, so that the inner wall of the tire must be
stretched, to cause it to properly embrace the rim and rest firmly in the holding
groove B. The tire C is preferably formed of an inner tube d of rubber, with a
covering e of thin canvas, so applied as to prevent the tire from bursting yet
allowing a slight longitudinal stretching of the wall of the tube d, and with an
outer covering of rubber, which forms the wearing tread of the tire, and with an
intervening non-extensible re-enforcement, of canvas or any other suitable non-
elastic material which serves to prevent the longitudinal stretching of the outer
wall 6' of the tire, when the tire is subjected to the pressure of inflation upon
the rim.
The tire C is also provided with the screw threaded valve tube h, through which
air can be forced for the proper inflation of the tire, the flat collapsing tube i which
is attached to the inner end of the valve tube h, serving to prevent the escape of
air from the chamber of the tire through the opening in the valve tube; and the
backward movement of the valve tube by unscrewing it from the surrounding
bushing will serve to allow the air to escape from the tire when it is desired to
lessen the pressure therein; a screw cap k being provided upon the outer end of the
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page_text: valve tube to prevent the entrance of sand or dust into the opening of the same,
when the tire is in use.
When the tire has been fully inflated, the non-extensible re-enforcement g, which
may be made of any suitable material, will prevent the increase of the diameter of
the outer circumferential wall, thus causing the pressure of the air contained in
the closed chamber j of the tire, to be fully exerted against the inner wall b, and the
bottom of the groove B, to hold the tire in place against laterally directed strain,
when the wheel is running upon an inclined track or surface; and imparting an
oval form to the cross section of the tire, as shown in Fig. 3, thus favoring the
yielding flexure of the side walls of the tire, at the bearing point upon the track.
In Fig. 3, the re-enforcement g is shown as applied in hollowed form to fit
against the covering e of the tube d. When the tire is made with a flat tread as
shown in Fig. 4, a flat band gi may be employed to prevent the extension of the
outer wall by the pressure of the air in the chamber j of the tire.
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. The combination with the vehicle wheel having a grooved rim, of an annular
pneumatic tire provided with a valved opening and made of less interior diameter
than the diameter of the rim of the wheel at the bottom of its groove, and having
a yielding inner wall adapted for extension longitudinally, to embrace the groove
of the rim, and a non-extensible re-enforcement in the outer peripheral wall, to
prevent the corresponding extension of the outer wall when subjected to the pressure
of inflation, substantially as described.
2.-The combination with a pneumatic tire, of the screw threaded valve tube,
adapted to relieve the pressure of air in the tire, and having an attached collapsing
tube which serves to prevent the escape of air through the opening in the valve
tube, substantially as described.
3.-The combination with a pneumatic tire, of the screw threaded valve tube
adapted to relieve the pressure of air in the tire, and having an attached collapsing
tube, which serves to prevent the escape of air through the opening in the valve
tube, and the screw cap adapted to close the outer end of the valve tube, substan-
tially as described.
Dated this Twenty-fifth day of June 1891.
PARDON WILBUR TILLINGHAST.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant