Improvements in Flexible Tubular Tires for Wheels of Vehicles.
Year: 1897

page_text: Date of Application, 9th Aug., 1897
Complete Specification Left, 6th May, 1898-Accepted, 18th June, 1898
[Communicated from abroad by DAVID ACHESON MCKNIGHT, of 501, F Street,
Washington, W.C., U.S.A.]
Improvements in Flexible Tubular Tires for Wheels of Vehicles.
I, JOHN WILLIAM MACKENZIE, of the Firm of Wheatley & Mackenzie, Engineers
and Patent Agents, of 40, Chancery Lane, in the County of London, do hereby
declare the nature of this invention to be as follows::
My invention relates to vehicle wheels furnished with rubber or other flexible
tubular tires, and consists primarily in providing the rim with a central normally
narrow seat for the tread of the tube of the tire, whereby when the tire is in place
there shall be on either side of its seat spaces between the tube and the rim into
which the upper or rim side of the tube may sink when under weight or pressure;
secondly in making the upper or rim side of the tread tube compressible and its
intermediate sides non-expansible or rigid, or substantially so; and third in making
the upper or rim side compressible, the under or tread side non-compressible, and the
intermediate sides rigid or non-expansible, whereby when seated on a rim of
the construction above described and under weight or pressure the tire will not be
compressed at the under or tread side, or expand at the intermediate sides, but will
yield or change its shape chiefly or wholly at the upper or rim side of the tube
alone.
By the term tubular tire is meant a hollow tire, whether the tube is cylindrical
or otherwise shaped. By the term "tread tube" is meant the tube which comes
in contact with the ground, whether the tire be a single or a double tube tire; in
the latter instance, it being sometimes called the casing. By the term narrow
seat is meant a seat approximating a mathematical line as nearly as is com-
patible with security. And by the terms "upper side," under side and intermediate
sides of the tube or tire is meant respectively that part thereof next the rim, that
part next the ground and the two parts midway beween the rim and the ground.
As pneumatic or other elastic tires have been usually applied to bicycle rims,
for example, the rim seat is made sufficiently wide to support the tire against
lateral pressure, and a large part of the tread tube lies closely against the concave
face of the rim, or is removed altogether from its median line and fastened at or
near the outer edges of the rim. In either case, there is under weight or pressure
no such flattening or compression of the tread tube on its rim side as there is on
its tread side, and therefore the elasticity of all that part of the tube so treated is
practically destroyed. If any part thereof could be saved, by just so much would
the elasticity of the tire as a whole be increased. And obviously an increase of
elasticity thus gained would admit of the thickening of the entire tube, or of that
side more subject to wear and tear: and thereby the required elasticity or
resiliency of the tire as a whole could still be maintained, whilst its durability
and resulting efficiency would be increased. By constructing the rim and elastic
tire in such manner that spaces are left between the tire and the rim, such flatten-
ing or compression takes place.

page_text: Ordinarily in bicycle tires, for example, the intermediate sides are pressed out
or expand when the under side is pressed in. By thickening or rendering the
intermediate sides of the tire substantially rigid or inexpansible in themselves
so as not to be held rigidly against expansion merely by the sides of the rim there
is a minimum of friction between the sides of the rim and the tire. If both the
under and intermediate sides of the tire are thickened and are substantially rigid
when in use the tire is protected from puncture; it would not be pressed in at
the under side or pressed out at the intermediate sides, it would be compressed
on its upper side alone, and the intermediate sides would slide easily up and down
against the sides of the rim. Being protected from exterior injury the upper side
of the tube might be made quite thin, with the effect of increasing the resiliency of
the tire. The under side of the tread tube being rigid, the curved tread would
always present the least surface to the roadway, to the avoidance of a great deal
of friction. And since the varying movements of the upper side of the tire when
in use would be without friction, a pneumatic tire would not require to be blown
up so tightly and the resiliency of its air-cushion would be thereby greatly
increased.
Dated this 9th day of August 1807
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.
Improvements in Flexible Tubular Tires for Wheels of Vehicles.
I, JOHN WILLIAM MACKENZIE, of the Firm of Wheatley & Mackenzie, Engineers
and Patent Agents, of 40, Chancery Lane, in the County of London, do hereby
declare the nature of this invention (a communication to me from David Acheson
McKnight, of 501, F Street, Washington, D.C., in the United States of America),
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
My invention relates to vehicle wheels furnished with rubber or other elastic
tubular tires, and consists, first, in providing a channelled rim whose sides (which
I herein term flanges) shall loosely engage the intermediate sides of the tire, and
centrally located in the channel a normally-narrow seat for the tread or inner tube
of the tire, and in making the inner side of the tube compressible whereby when
the tire is in place there shall be on either side of its seat in the bottom of the
channel spaces into which the inner side of the tube may sink when under sufficient
external pressure, the intermediate sides of the tube having a reciprocating motion
between the flanges when the wheel is running under load; second, in making
the intermediate sides of the tire non-expansible, or substantially so, and in pro-
viding the rim with suitable antifriction devices for engaging them, whereby when
the tire is seated as above described the reciprocating motion shall be made with
a minimum of friction; third, in making the intermediate sides of the tire non-
expansible and the outer side transversely non-compressible, or substantially so,
whereby when the tire is seated as above described the outer and intermediate sides
shall retain their normal shape and the cushion effect shall be caused wholly or
chiefly by the compression of the inner side of the tire alone; fourth, in providing a
central peripheral rib in the bottom of the channelled rim as a seat for the tire:
and, fifth, in the other constructions and arrangements hereinafter described and
claimed.
By the term "tubular tire" as used in this specification is meant a hollow tire,
whether the tube be cylindrical or otherwise shaped. By the term tread tube"
66

page_text: is meant the tube which comes in contact with the ground, whether the tire be a
single or a doublé tube tire; in the latter instance, it being sometimes called the
cover or casing. By the term narrow seat is meant a seat approximating a
mathematical line as nearly as is compatible with security. By the term rigid
68
"
"
is meant such degree of rigidity as may prevent the so-called rigid portions from
unduly changing their shape as above described. And by the terms "inner side,"
outer side," and "intermediate sides" of the tube or tire are meant respectively
that part thereof next the rim, that part next the ground, and the two parts
midway between the rim and the ground.
As pneumatic or other elastic tubular tires have been usually applied to bicycle
rims, for example, a large part of the tread tube lies closely against the concave
face of the rim, or (as in tires of the clincher type), is removed altogether from its
median line and fastened at or near the outer edges of the rim. In either case
there is under pressure of the rider's weight no such flattening or compression of
the tread tube on its rim side as there is on its tread side, and therefore the
resiliency of all that part of the tube so treated is practically destroyed. If any
part thereof could be saved, by just so much would the resiliency of the tire as a
whole he increased. And obviously an increase of resiliency thus gained would
admit of the thickening of the entire tube, or of that side more subject to wear
and tear; and thereby the required elasticity or resiliency of the tire as a whole
would still be maintained, whilst its durability and resulting efficiency would be
increased. The desired result is accomplished by my primary invention as herein
described.
Ordinarily in bicycle tires, for example, the intermediate sides are pressed out,
or spread, or expand, when the under side is pressed in; and such would be the
effect of external pressure or load on the tires illustrated in Figs. 1 and 2. But
in Figs. 3 and 4 the intermediate sides of the tire are shown as thickened, and are
supposed to be substantially rigid or non-expansible in themselves,--so made by
any suitable means, and not to be held rigidly against expansion merely by the
sides of the rim; and thereby there is a great decrease in friction during the
reciprocating movements of the tire, which is reduced to a minimum by having
spring flanges or interposing springs or other anti-friction devices between the
flanges and the tire. The other sides of the tire are also shown as thickened, and
are supposed to be substantially rigid or non-compressible under load. Constructed
as in Figs. 3 and 4, a rubber tire when in use would be protected from puncture,
it would not be pressed in at the outer side or pressed out at the intermediate sides,
it would be compressed on its inner side alone, and the intermediate sides would
slide easily up, and down against the sides and r of rim R. Being protected from
exterior injury, the inner side of the tread tube might be made quite thin, with the
effect of increasing the resiliency of the tire. The outer side of the tread tube
being rigid, the curved tread shown in Fig. 3 would always present the least
surface to the roadway, to the avoidance of a great deal of friction. Since the
varying movements of the inner side of the tire when in use would be without
friction, a pneumatic tire would not require to be blown up so tightly, and the
resiliency of its air-cushion would be thereby greatly increased. And if a
pneumatic tire so constructed were temporarily deflated, the wheel would still run
very well and without injury to the tire, though of course without its normal
resiliency.
?
In the drawing Figs. 2 and 3 show a single tube and Figs. 1 and 4 a double
tube tire in section, supposed to be made of rubber, and they illustrate different.
forms of applying my invention to a wheel rim, which are at present preferred
forms, the invention however not being confined to any of the details of construction
shown, apart from those above mentioned. R represents a wheel rim having a
channelled face, and and r are its two flanges or sides, which as shown protect
the tire, from undue rolling or lateral displacement. In their normal position the
rim sides may touch the intermediate sides of the tire as shown in Figs. 1, 3 and 4,
or may fall short of doing so as indicated in Fig. 2. They may have spring ends

page_text: as indicated in Fig. 1, or be substantially rigid as in Figs. 2, 3 and 4; or springs
may be interposed between the tire and the rim sides, if desired. P is a projection
or rib in the bottom of the rim channel, which constitutes the central seat for the
tire. Pin Fig. 4 is a projection or rib on the inner side of the tube, and may be
either split or solid. It is shown as resting in groove G, and it is the equivalent
of rib P. In Figs. 1 and 2 projection P is shown as grooved for the admission of
dovetail D of the tyre, but this is merely illustrative, the manner of securing the
tire to its seat being no part of my invention. S and S are spaces at the bottom
of the channel on either side of the rib. Tis the tread tube, and A the inner tube,
of the tire. In all of the figures the outer side or tread of the tire is shown as
thickened for the prevention of puncture. L in Fig. 1 is a layer of fibrous or other
suitable puncture-proof material, and in Fig. 3 it represents a metallic shield; in
the latter case it extends thorugh the intermediate sides and renders them non-
expansible, and in both cases the armor may be made sufficiently rigid to render
the outer side non-compressible or substantially so; but the means by which the
tube is made puncture-proof is no part of my invention, and any suitable means
may be used if a puncture proof quality be desired.
All of the figures in the drawing illustrate the primary and fourth parts of my
invention, and Figs. 3 and 4 illustrate the second, third, and fifth parts thereof, as
above described. Necessarily the flexibility of the tread side of a tire is lessened
by thickening or armoring it, and I therefore transfer the flexibility to its inner
side, where it is utilised in the manner above explained. Since the flanges engage
the tube loosely, the inner side of a pneumatic tire when running under load would
not expand or dilate, and so fill up the spaces on either side of its seat, as it would
if the tube were held tightly against the flanges by the increased air pressure or
otherwise; but, on the contrary, by reason of the reciprocal movement of the tube
between the flanges, its inner side would be compressed against the rim precisely
as its outer side if of a similar flexibility would be compressed against the ground.
Hence my invention applies not only to pneumatic tires, but to elastic tubular
tires of any kind; and it may also be used with tires of the clincher type, if
desired.
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. An elastic tubular tire having its inner side compressible in combination
with a vehicle wheel rim having a channelled face and in the channel a central
narrow seat for the tube or tubes with spaces on either side thereof in the bottom
of the channel when the tire is in place, and having flanges adapted to loosely
engage the intermediate sides of the tire, substantially as and for the purposes
described.
2. An elastic tubular tire having its inner side compressible and its intermediate
sides rigid in combination with a wheel rim having a channelled face and in the
channel a central seat for the tube or tubes with spaces on either side thereof in the
bottom of the channel when the tire is in place, and having springs or other anti-
friction devices adapted to engage the intermediate sides of the tire, substantially as
and for the purpose described.
3. An elastic tubular tire having its inner side compressible and its outer
and intermediate sides rigid in combination with a wheel rim having a channelled
face and in the channel a central seat for the tube or tubes with spaces on either
side thereof in the bottom of the channel when the tire is in place, and having
flanges adapted to loosely engage the intermediate sides of the tire, substantially
as and for the purposes described.
4. An elastic tubular tire having its inner side compressible in combination with
a vehicle wheel rim having a channelled face and in the channel a central peripheral
rib as a seat for the tube or tubes with spaces on either side thereof in the bottom
of the channel when the tire is in place, and having flanges adapted to loosely

page_text: engage the intermediate sides of the tire, substantially as and for the purposes
described.
5. An elastic tubular tire having a compressible inner side in combination with
a wheel rim having side flanges, said tire and rim being so arranged that its tube
or tubes shall have a reciprocating motion between the flanges and that its inner
side shall be compressed when running under load, substantially as and for the
purposes described.
6. An elastic tubular tire having rigid outer and intermediate sides and a com-
pressible inner side provided with a peripheral rib in its median line, substantially
as and for the purposes described.
7. The several constructions, combinations, and arrangements of parts embodied
in my invention, substantially as herein described and illustrated by the accom-
panying drawing.