AN IMPROVED WHEEL FOR STEAM CARRIAGES TO BE USED ON COMMON ROADS
Year: 1867

page_text: LETTERS PATENT to Robert William Thomson, of Edinburgh, in the
County of Mid Lothian, North Britain, Civil Engineer, for the Invention
of "AN IMPROVED WHEEL FOR STEAM CARRIAGES TO BE USED ON COMMON
ROADS."
Sealed the 21st April 1868, and dated the 24th October 1867.
PROVISIONAL SPECIFICATION left-by the said Robert William Thomson
at the Office of the Commissioners of Patents, with his Petition, on the
24th October 1867.
I, ROBERT WILLIAM THOMSON, of Edinburgh, in the County of Mid Lothian,
North Britain, Civil Engineer, do hereby declare the nature of the said
Invention for "AN IMPROVED WHEEL FOR STEAM CARRIAGES TO BE USED ON
COMMON ROADS," to be as follows, that is to say :-
This Invention relates to an improved wheel for steam carriages intended
to run on common roads, and consists in applying to the wheels external bands.
or tires of vulcanised rubber, instead of making such wheels with tires or
external treading surfaces of iron or wood, as hitherto. The rubber tire may
be kept on the wheel by flanges, the wheel being made of iron in the usual
way, and with a rim of considerable width. The elastic tire is made of a
little less diameter than the wheel, and being stretched in order to get it on
the wheel has a tendency to contract, which helps to keep it in its place.

page_text: The width of the tire is made a little less than the width between the
flanges of the wheel rim, and its thickness radially is such that it projects a few
inches beyond the flanges, which consequently do not touch the ground.
Amongst the advantages of the improved elastic tires are their presenting a
. bearing surface of greater extent circumferentially than ordinary rigiḍ. and
unyielding tires, in consequence of which they do not grind the surface of the
roadway nor sink into it, and they thus enable the steam carriage to be pro-
pelled over bad roads with less power than that required with rigid tires.
They also admit of the ordinary springs being dispensed with, and consequently
of the driving power being applied to the wheels by means of simpler gearing
or mechanism than has hitherto been found requisite.
Steam carriages with the improved wheels may pass over grass land and
even over ploughed land with very little sinking into the soil, thus enabling
such carriages when used for agricultural purposes to travel over farm lands
with much less difficulty than is experienced with steam carriages having
rigidly tired wheels. For some purposes the rubber tire may be protected by
an external flexible covering of iron, made of connected or jointed bars or
links, or of chain links and like chain mail.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert William Thomson in the Great Seal Patent Office
on the 22nd April 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
WILLIAM THOMSON, of Edinburgh, in the County of Mid Lothian, North
Britain, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date. the Twenty-fourth day of October, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Robert William Thomson, Her special licence that I, the said
Robert William Thomson, my executors, administrators, and assigns, or such
others as I, the said Robert William Thomson, my executors, administrators,
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
AN IMPROVED WHEEL FOR STEAM CARRIAGES TO BE USED ON COMMON ROADS,"

page_text: upon the condition (amongst others) that I, the said Robert William Thomson,
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 per-
formed, and cause the same to 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 Robert William Thomson, 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 in writing, reference being had to the accompanying
Drawings, that is to say :-
My said Invention relates to an improved wheel for steam carriages
intended to run on common roads, and consists in applying to the wheels of
such carriages external bands or tires' of vulcanised rubber, instead of making
such wheels with tires or external treading surfaces of iron or wood, as
hitherto.
And in order that my said Invention and the manner of performing the
same may be properly understood, I have hereunto appended a Sheet of
explanatory Drawings to be herein-after referred to, and representing modifi-
cations of my improved wheel. The same reference letters are used to mark
the same or like parts in all the Figures.
Figure 1'is a face view of one modification, and Figure 2 is a section as
taken in a plane through the axis of the wheel. In this example the body or
frame of the wheel is represented as built up or constructed of wrought-iron
plates strengthened by angle iron and by diagonal stays, but my Invention is
equally applicable to wheels constructed otherwise.
The wheel is formed with a cylindrical rim or shell A, and with flanges B, B,
the space between such flanges constituting a broad shallow circumferential
groove. The' rubber tire C is moulded and vulcanised or cured, in the form of
a complete ring; with its inner cylindrical surface a little smaller in diameter
than the cylindrical surface A of the wheel, and it is stretched to get it into its
place' on the wheel surface A; the elastic tension due to its being stretched
assists in keeping the rubber tire C in its place, and the flanges B also prevent
its displacement. The width of the tire C is made a little, less than the width
between the flanges B of the wheel, and its thickness radially is such that it
projects a few inches beyond the flanges B, which consequently do not touch
the ground.
Amongst the advantages of my improved elastic tires are their presenting

page_text: a bearing surface of greater extent circumferentially than ordinary rigid and
unyielding tires, in consequence of which they do not grind the surface of the
roadway nor sink into it, and they thus enable the steam carriage to be pro-
pelled over bad roads with less power than that required with rigid tires.
They also admit of the ordinary springs being dispensed with, and consequently
of the driving power being applied to the wheels by means of simpler gearing
or mechanism than has hitherto been found requisite.
Steam carriages with my improved wheels may pass over grass land and
even over ploughed land with very little sinking into the soil, thus enabling
such carriages, when used for agricultural purposes, to travel over farm lands
with much less difficulty than is experienced with steam carriages having
rigidly tired wheels. For general purposes vulcanised rubber tires of the
shape shown in Figures 1 and 2 will be found sufficient. When the wheels
are to work on soft ground the tread of the rubber tire C may be corrugated,
as shown in Figure 8; these corrugations will give the tire a good grip on soft
ground or on ploughed land; they will sink into the ground when it is soft,
and they will be flattened when passing over ordinary roads. The corrugations
may be varied in shape and size to suit the various kinds of soil and surface
over which the tires have to work. Projections of hemispherical or other
suitable forms may be substituted for corrugations of the kind shown in
Figure 8.
.
Figure 4 is a face view of another modification; and Figure 5 is a section
as taken in a plane through the axis of the wheel. In this example the
flanges (B, Figures 1 and 2) are omitted, and clips D are employed to hold
the vulcanised tire C on the wheel rim A; these clips D are connected by
distances
links E, jointed on studs at the sides, and are thereby kept at proper
apart. The clips D may be used in combination with flanges (B) also; but
it will generally be more convenient to use the rubber tires with the flanges
only. It is found in practice that the rubber tires do not suffer any injury in
passing over rough roads covered with broken stones, and therefore the pro-
tection of a flexible iron covering may in general be dispensed with; but if it
is in any case considered desirable to apply such a covering it may very
conveniently be made to consist of clips D, such as are shown in Figures 4
and 5, and which clips may be placed as close together as desired; or separate
loose clips may be added between those which are shown as linked together,
so as to nearly fill up the entire treading surface of the tire.
Having thus particularly described my said Invention, and the manner in
which the same is to be performed, I have to state that I do not restrict myself
to the precise details herein described or delineated; but that what I believe

page_text: to be novel and original and claim as the Invention secured to me by the
herein-before in part recited Letters Patent is, the applying of tires of
vulcanised rubber to the wheels of steam carriages, such as are used on
common roads.
In witness whereof, I, the said Robert William Thomson, have hereunto
set my hand and seal, this Twenty-first day of April, in the year of
our Lord One thousand eight hundred and sixty-eight.
R. W. THOMSON. (L.S.)