IMPROVEMENTS IN THE CONSTRUCTION. OF ELASTIC TYRES FOR WHEELS
Year: 1870

page_text: LETTERS PATENT to Isaac Blue Harris, of Castle Mills, Edinburgh,
North Britain, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION.
OF ELASTIC TYRES FOR WHEELS."
Sealed the 15th November 1870, and dated the 12th August 1870..
.
PROVISIONAL SPECIFICATION left by the said Isaac Blue Harris at
the Office of the Commissioners of Patents, with his Petition, on
the 12th August 1870.
I, ISAAC BLUE HARRIS, of Castle Mills, Edinburgh, North Britain, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN.
THE CONSTRUCTION OF ELASTIC TYRES FOR WHEELS," to be as follows:-
These improvements relate to the construction of india-rubber tyres
to be placed outside of the rigid tyres hitherto in use, and consist,-
First. In introducing into the india-rubber tyre one or more layers of
canvas or any flexible but not extensible material, and placing the same
at any suitable distance from the inside of said tyres. The use of this
canvas is to prevent the rubber from elongating under compression and

page_text: to keep it in the groove or between the flanges of the wheel without the
use of guides otherwise necessary to keep the tyre between the flanges of
the wheel.
Second. In forming the tyres with a groove or hollow all round their
edges, so as to allow of a more easy compression, and to prevent the
rubber from being injured by rubbing against the flanges of the wheel
when under compression, and at the same time reducing the expansion
of the rubber in front of the bearing part of the wheel and thereby
reducing the resistance to the progress of the wheel caused by such
expansion.
Third. In employing one such improved tyre about equal in width to
the width of the wheel face, or two or more narrower ones formed either
with or without a groove in their sides, making together the width
required for the compressible tyre of any wheel, and in attaching such
tyre or tyres to the rigid tyre of the wheel by means of a layer of hard
or semi-hard vulcanized india-rubber (known as vulcanite or ebonite)
vulcanized on to a metal hoop made to fit, and by which the rubber tyre
is attached to the rigid metal or wooden tyre hitherto in use; said rubber
tyre having the canvas layers already described, or layers of wire cloth
instead of such canvas layers.
Fourth. In employing outside of such tyre or tyres an endless belt,
shield, or covering, constructed of india-rubber and canvas or of leather
or of any flexible material, having metal plates on each side rivetted
together or otherwise suitably united, so as to cover and protect the
rubber tyre or tyres from injury from the road, which belt, shield, or
covering may be made separately and placed over the rubber tyre or may
be made in a piece with it.
'
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Isaac Blue Harris in the Great Seal Patent Office
on the 11th February 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, Isaac Blue
HARRIS, of Castle Mills, Edinburgh, North Britain, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of August, in the year of
3

page_text: our Lord One thousand eight hundred and seventy, in the thirty-fourth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Isaac Blue Harris, Her special licence that I,
the said Isaac Blue Harris, my executors, administrators, and assigns,
or such others as I, the said Isaac Blue Harris, my executors, adminis
trators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE CON-
STRUCTION OF TYRES FOR WHEELS," upon the condition (amongst others)
that I, the said Isaac Blue Harris, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Isaac Blue Harris, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereunto
annexed and to the letters and figures marked thereon (that is to.
say) :-
This Invention relates to an improved mode of constructing india-
rubber tyres to be applied to the rigid tyres of traction and other carriage
wheels employed on common roads.
In order to prevent the perimeter of the india-rubber of which the
elastic tyre is mainly composed from extending under compression, I
introduce into the india-rubber one or more layers of canvas or other
like flexible but non-extensible material, placing the same near the base
or at any suitable position in the-thickness of the tyre, as hereafter
indicated, and I so form the tyre or the elastic component parts thereof, as
to allow of a more easy compression of the india-rubber than heretofore,.
and to protect the rubber from being injured by being pressed against
the flanges of the wheel when under compression, and at the same time
reduce the tendency of the rubber to crowd in front of the bearing part

page_text: of the wheel, and offer thereby an increased resistance to the progress of.
the wheel.
My improved tyre I make either in one piece, equal in width to the
width of the wheel face, or of two or more annular sections, formed either
with or without a groove in their sides, and together completing the
width required for the compressible tyre of the wheel, and I provide for
the attachment of such tyre or annular sections to the rigid tyre of the
wheel by means of a layer of hard or semi-hard vulcanized india-rubber,
(known as vulcanite or ebonite) vulcanized on to a metal hoop made to
fit the rigid metal or wooden tyre of the wheel, said rubber tyre having
the canvas layers already described or layers of wire cloth instead of such
canvas layers. To complete the elastic tyre thus far formed, I apply
thereto an endless band, shield, or covering, constructed of india-rubber
and canvas, or of leather, or of any other suitable flexible material, having
attached to its opposite sides metal plates which are rivetted together-
through the band or otherwise suitably connected.
By clothing the elastic tyre with this flexible metallic band I am
enabled to protect it from injury from the road and render it very durable
while by the means to be hereafter described I ensure its secure and
efficient attachment to the elastic tyre.
The improved tyre with its metallic band forming together a clothed
elastic rubber tyre is shewn in several views in the accompanying
Drawing.
Fig. 1 represents a cross section of my improved wheel tyre, applied
to the rigid tyre of a running wheel, and Fig. 2 is a partial side view of
the same.
In Fig. 1 W is the rigid wheel tyre, and ƒ are the side flanges for
holding the elastic tyre in position on the wheel. These flanges may be
attached thereto by bolts b, or otherwise fitted to the rigid wheel tyre
W are dividing or partitioning metal rings h¹, which are interposed
between the several annular sections R, R, R, of elastic material com-
posing the compressible tyre. These annular sections R are mainly
composed of india-rubber, and I sometimes form them upon metal hoops
h which when applied to the wheel are kept apart by the partitioning
hoops h¹. By the use of the base hoops h the tyre sections R may be
conveniently fitted to the rigid wheel tyre W. The annular sections R
are made by preference with concave sides as shown, I form them with a

page_text: hard rubber base next the hoop h, and overlay this rubber with several
laps of canvas C or other non-extensible but flexible material attached
and combined with the rubber. Outside of the canvas laps the com-
pression of the rubber tyre takes place, and spaces for the displacement
of the rubber are provided by the concave sides, or in the partition spaces
between the annular sections, surrounding the sections R, R, R, R, is a
continuous band B made of leather, or india-rubber and canvas, enclosed
between suitable external metal plates A and internal metal plates a
which plates are connected together by rivets r. The plates a are pro-
vided with projections p which extend between any two of the annular-
sections R, and thereby serve to keep the band B with its metal coverings
from slipping sideways off the wheel. Instead of or together with these
projections side projections as p', Fig. 4, may be employed for keeping.
the band B on the wheel. The form and arrangement of these projections
are further shewn by the circular sectional view Fig. 3, where corre-
sponding parts as in Fig. 4 are marked with corresponding letters to
those in Fig. 1.
The outside band B I make about an inch or an inch
and one half thick.
If desired I make the flanges f to embrace the ends of the under metal
coverings a, and thus keep the band B on the surface of the tyre by the
flanges without the use of the projections p just described, and further
by this means the flanges enclose the rubber tyres wholly within and
between them. This modification is shown in cross section at the left
hand side of Fig. 5.
Figures 6 and 7 are views of the tyre shewn at Fig. 5. Fig. 6 being
a section taken at the line A, B, and Fig. 7 a section taken at the line
C, D, of that Figure. W is the rigid wheel tyre, and R the compressible
tyre as before made with a base of vulcanite or hard rubber that projects
laterally slightly beyond the elastic or soft rubber; fand f* are the wheel
flanges held by bolts or screws to the wheel, the flange f* shewing the
extension above referred to. These flanges are preferably made in
sections, and have their outer edges bent inwards, as shewn at Fig. 5.
Between the annular sections a ring t having a T shaped section is placed,
it being so formed in order with the help of the lapping parts of the
flanges to keep the tyre sections by their vulcanite bases to the surface
of the wheel. These vulcanite bases are vulcanized with and thereby
attached to the soft rubber R, and are stayed and strengthened by metal
bars m embedded in the vulcanite and extending with it between the

page_text: flanges and the ring t. kare similar metal pieces which may be
employed for keying the vulcanite base to the rigid wheel tyre if desired.
By means of these vulcanite or combined vulcanite and metal bases the
annular sections R are conveniently held to the surface of the rigid tyre
W, and an easy means is further provided for removing and replacing
the several sections, which I sometimes employ to form a compressible
tyre whereby it can be repaired and replaced in detail, and in localities
far removed from rubber manufactories. Instead of placing the layers of
canvas around or near the base of the several rubber rings, I sometimes
place it on the outside as at C, Fig. 5, and if desired the canvas may be
dispensed with altogether.
Outside of the tyre R, however formed, I place the covering band B as
already described with reference to Figures 1 to 4.
Having now set forth the nature of my Invention of "Improvements
in the Construction of Tyres for Wheels" and explained the manner of
carrying the same iuto effect, I wish it to be understood that under the
above in part recited Letters Patent I claim, constructing elastic tyres
and clothing the same in the manner and for the purpose above
described.
In witness whereof, I, the said Isaac Blue Harris, have hereunto
set my hand and seal, this Eighth day of February, in the year of
of our Lord One thousand eight hundred and seventy-one.
I. B. HARRIS. (L.S.)
Witness,
WILLIAM FIRTH,
Sec, North British Rubber Co., Limited,
Edinburgh.