IMPROVEMENTS IN TRACTION ENGINES
Year: 1859

page_text: LETTERS PATENT to Patrick Stirling, of Kilmarnock, in the County of
Ayr, North Britain, for the Invention of "IMPROVEMENTS IN TRACTION
ENGINES."
Sealed the 8th June 1860, and dated the 12th December 1859:
PROVISIONAL SPECIFICATION left by the said Patrick Stirling at the
Office of the Commissioners of Patents, with his Petition, on the
12th December 1859.
IN
I, PATRICK STIRLING, of Kilmarnock, in the County of Ayr, North Britain,
do hereby declare the nature of the said Invention of "IMPROVEMENTS
TRACTION ENGINES," to be as follows, that is to say:-
This Invention relates to certain improvements in the arrangement and
construction of the parts of traction engines, and has for object to render such
engines more efficient, manageable, and durable, and less costly. A machine
embodying a modification of the improvements comprises a rectangular frame
mounted upon a single central driving wheel, a pair of leading wheels, and a
pair of trailing wheels. A boiler, by preference of the vertical class, and a
pair of horizontal steam cylinders are mounted upon the frame, together with
a tank or receptacle for water and fuel. A single cylinder may be used if
preferred, it, or the two, being arranged to drive a first motion shaft, having
fast on it a pinion in gear with a spur wheel on the side of the driving wheel.
or fast on the shaft thereof. All the wheels are mounted with springs, and an
[Price 8d.]

page_text: adjustable contrivance is applied to the driving wheel springs, by means of
which the weight of the machine may be made to bear more or less exclusively
upon the driving wheel. It is proposed to make the driving wheel with a
wooden treading surface, formed by enclosing wooden blocks between metal
cheeks, in such a way as to present the fibres radially. The bite of the
treading surface may be increased, if necessary, by inserting spikes, points, or
ribs, or an ordinary iron hoop may be used, in certain cases where great
adhesion is not required. The leading and trailing wheels are mounted loose
on axles arranged to swivel, being made to do so in concert by means of rods
formed with rack teeth, so as to be acted upon by a pinion worked by means
of a screw and worm. The rod from one axle passes over the pinion, and the
rod from the other under it, and the axles are thereby made to swivel in
opposite directions, by which means a double effect is obtained, and the
machine is made to move in a curve of much less radius than is obtainable
with ordinary contrivances for the same purpose.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Patrick Stirling in the Great Seal Patent Office on the
12th June 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PATRICK
STIRLING, of Kilmarnock, in the County of Ayr, North Britain, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of December, in the year of our
Lord One thousand eight hundred and fifty-nine, in the twenty-third year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Patrick Stirling, Her special licence that I, the said Patrick
Stirling, my executors, administrators, and assigns, or such others as
I, the said Patrick Stirling, my executors, administrators, and or 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 TRACTION ENGINES," upon the condition (amongst
others) that I, the said Patrick Stirling, my executors, 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

page_text: Invention, and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar months from
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Patrick Stirling, 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, and
to the letters and figures marked thereon, that is to say:-
A
My said Invention relates to certain improvements in the arrangement and
construction of the parts of traction engines, and has for object to render
such engines more efficient, manageable, and durable, and less costly.
machine embodying a modification of the improvements comprises a rectangular
frame mounted upon a single central driving wheel, a pair of leading wheels,
and a pair of trailing wheels. A boiler, by preference of the vertical class,
and a pair of horizontal steam cylinders are mounted upon the frame, together
with a tank or receptacle for water and fuel. A single cylinder may be used
if preferred, it, or the two, being arranged to drive a first motion shaft, having
fast on it a pinion in gear with a spur wheel on the side of the driving wheel,
or fast on the shaft thereof. All the wheels are mounted with springs, and an
adjustable contrivance is applied to the driving wheel springs, by means of
which the weight of the machine may be made to bear more or less exclusively
upon the driving wheel. It is proposed to make the driving wheel with a
wooden treading surface, formed by enclosing wooden blocks between metal
checks in such a way as to present the fibres radially. The bite of the
treading surface may be increased, if necessary, by inserting spikes, points,
or ribs, or an ordinary iron hoop may be used in certain cases where great
adhesion is not required. The leading and trailing wheels are mounted loose
on axles arranged to swivel, being made to do so in concert in opposite
directions, whereby a double effect is obtained, and the machine is made to
move in a curve of much less radius than is obtainable with ordinary con-
trivances for the same purpose.
And in order that my said Invention may be properly understood and
carried into effect, I have hereunto appended and shall now proceed to
describe a Sheet of explanatory Drawings representing a traction engine con-
structed with one modification of my improvements.
Figure 1 is a side elevation, and Figure 2 is a plan of the engine. The
rectangular framing consists of two longitudinal or side timbers A, strengthened
by outside and inside plates of iron and four transverse timbers B. The side
frame plates are formed with lower and upper horn plates C, c, the former to

page_text: receive the bearings d of the axle of the main driving or traction wheel D,
and the latter c to receive the bearings e of the first motion shaft E. The
traction wheel D is in this example an iron casting of considerable weight, its
treading surface being formed of wooden blocks F jammed in between the
iron cheeks, and presenting a circumferential surface of end wood. The
bearings d of the traction wheel are connected to the framing by springs G
and links g, the latter' being made adjustable by means of right and left screw
couplings, so that the weight of the carriage may be made to bear more or less
upon the traction wheel D. The traction wheel D is formed with a ring of
teeth H (on one side, or) on each side, in gear with which is a pinion I fast
on the first motion shaft E, the respective bearings e and d being connected
by rods to keep the wheels in gear. The first motion shaft E is formed with
outside cranks K, and is actuated by a pair of horizontal cylinders L placed
upon the water tank M at the back end of the carriage. The water tank is
mounted upon the longitudinal frames A, and pair of cross frames B
extending downwards within the latter, and having its lower part made
cylindrical, to admit of its passing within a circular plate N, to which the
trailing wheels O are connected. The circular plate N works upon or beneath
a circular plate n fixed immediately beneath the side frames A, and has fixed
to it scroll irons p linked to springs P, which last are fixed on the axle Q of
the trailing wheels O, these wheels turning loosely on their axle. Similarly
the leading wheels R are mounted loose on an axle S, to which are fixed
springs T linked to scroll ironts t, these scroll irons being fixed to a circular
plate U, which works beneath a fixed circular plate u attached to the under
side of the side frames A. The moveable circular plates U, N, of the leading
and trailing wheels are formed with worm teeth, with which gear worms V on
a horizontal shaft W, carried by brackets fixed to the side frames A, and fitted
with a hand wheel wat its front end. The worms V are one right-handed
and the other left-handed, the respective worm teeth on the circular plates
U, N, being formed to correspond; with which arrangement the turning of
the worm shaft W will cause the leading and trailing wheels to swivel in
opposite directions, and the machine to turn in a comparatively very small
compass in consequence. The boiler X of the vertical cylindrical class in this
example is placed within the circular plate U of the leading wheels, being
supported by means of a flange resting on the side frames A and the forward
pair of cross frames B. The boiler is fired from the front, a foot plate Y
being provided for the attendant. It is preferred to place the various levers
or hand wheels for controlling the action of the machine at the front end
thereof; but as the present Invention has no special reference to such parts of

page_text: the machine, it has been thought unnecessary to show in the Drawings the
various details connected therewith.
Having thus particularly described my said Invention, and the manner
in which the same is or may be used or carried into effect, I have
to state that I do not restrict myself to the precise details herein described
or delineated, that my Invention does not include the use of a single traction
wheel when made of considerable breadth, or so as to enclose the boiler and
driving machinery, or a portion thereof, as has been proposed, as such con-
struction is in practice accompanied by those defects common to two wheels,
which I propose to obviate by the use of a single narrow wheel; but
what I consider to be novel and original, and claim as the Invention secured
to me by the herein-before in part recited Letters Patent, is,-
First, the use in traction engines of a single narrow traction wheel placed
at the centre or at either end of the machine.
Second, the constructing of traction engines with leading and trailing
wheels capable of swivelling in opposite directions, substantially as herein-
before described.
In witness whereof, I, the said Patrick Stirling, have hereunto set my
hand and seal, this Eleventh day of June, in the year of our Lord
One thousand eight hundred and sixty.
Witness,
EDMUND HUNT, Patent Agent,
28, St. Enoch Square, Glasgow.
TAIMUA DIIRLING. (4.3.)