IMPROVEMENTS IN TRACTION ENGINES
Year: 1875

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention
of "IMPROVEMENTS IN TRACTION ENGINES."-A communication from
abroad by William H. Milliken, of Sacramento, in the County of
T
Scaled the 30th July 1875, and dated the 21st April 1875.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 21st April 1875.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN TRACTION ENGINES," to be as
follows:-

page_text: of the wheels, which can at the same time be turned readily from right
to left, and vice versa, for steering the machine and for turning
around.
And, Secondly. To mount the body so that the weight will be equally
distributed and at all times borne on the wheels alike, no matter what
irregularities there may be in the surface, and at the same time make
the connection by springs to obtain the necessary elastic support without
the use of rubber.
The first part of the Invention is effected by mounting each wheel on
a short independent axle, which is supported in bearings each side of
the wheel in the lower end of a yoke extending up over the wheel, and
pivoted vertically by its inner member to the body to allow the wheel to
turn for steering and going round curves, and also to slide up and down
to allow one wheel to vibrate vertically independently of the other, to
accommodate the wheels to uneven ground, while the body remains lovel
or nearly so. The propelling force of the wheels is also applied to the
body by means of this connection. The inner end of the axle is con-
nected by a section having a joint at each end with a middle section
carrying the driving wheel, and arranged in boxes attached rigidly to the
body of the carriage. The joints of these sections are formed by
universal couplings, which allow the wheels to turn sidewise and oscillate
vertically, while the middle section receives and transmits the force
without obstruction by such turning. The driving wheel is geared to
the crank shaft of the engines by mechanism, also carried in the body,
and therefore positively connected with it, while it is flexibly connected
with the wheels so as to rise and fall readily, and so that they can turn
laterally for guiding and turning around. The front and rear axles are
constructed and arranged and geared with the engine alike. For
turning the wheels and axles laterally to steer the machine and to turn
around the outer ends the axles are connected by rods with a vertical
rock lever on a shaft between the fore and hind wheels, and extending
from side to side to receive both rock levers, and geared by worm gears
with the steering wheel to be worked by hand. The rock levers draw
the wheels together on one side and force them apart on the other side,
and thus direct the machine as desired.
The second part of the Invention is effected by the use of equalizing

page_text: supports arranged in pairs under the body transversely on a pivot at the
middle attached to the body, and carrying at the ends springs supported
between the two equalizers of each pair by being connected to their
ends, and these springs are supported by the yokes in which the wheels
are mounted, and on which the body has vertical movements, allowing
the necessary action to compensate for the unevenness of the ground.
The equalizers may be dispensed with, and the springs may be con-
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filod by the said Alexander Melville Clark in the Great Seal Patent
Office on the 15th October 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 58, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of April, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alexander Melville Clark, Her special
licence that I, the said Alexander Melville Clark, my executors, adminis-
trators, and assigns, or such others as I, the said Alexander Melville
Clark, 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 "Im-
PROVELIENTS IN TRACTION ENGINES," a communication to me from abroad by
William H. Millikin, of Sacramento, in the County of Sacramento, State
of California, United States of America, upon the condition (amongst
others) that I, the said Alexander Melville Clark, my executors or ad-
ministrators, 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

page_text: The second part of the Invention is effected by the use of equalizing
supports arranged in pairs under the body transversely on a pivot at the
middle attached to the body, and carrying at the ends springs supported
between the two equalizers of each pair by being connected to their
ends, and these springs are supported by the yokes in which the wheels
are mounted, and on which the body has vertical movements, allowing
the necessary action to compensate for the unevenness of the ground.
Figure 1 is a side elevation of a traction engine cons
arranged according to the present Invention; Figure 2 is a plan of the
machine inverted; Figure 3 is a transverse section on line X, X, of
Figure 1; and Figure 4 is a detail of the driving gear in side elevation.
Similar letters of reference indicate corresponding parts.
A represents the supporting and driving wheels, which are mounted
on short independent axles B, having a bearing each side of the wheel
in the boxes C of a yoke D extending up over the wheel, and connected
by its inner arm with the body E by a box F, in which it can turn to
allow the wheel to turn for steering and going around curves, and it can
also slide up and down to allow one to vibrate vertically independently
of the other, to accommodate the wheels to uneven gronnd, while the
body remains level or nearly so. The propelling force of the wheels is
also applied to the body by means of this connection. The axles aro
jointed at the inner end to a section G, which is itself jointed to the
middle section H carrying the driving wheel I, and arranged in boxes J
rigidly attached to the truck body. The joints of these sections are
formed by universal couplings, which allow the wheels to turn sidewise
and oscillate vertically, while the middle section receives and transmits
the force without obstruction by such turning. The driving wheel is
geared to the crank shaft of the engine by the countershaft K. The
front and rear axles are constructed and arranged and geared with the
engine alike. To turn the wheels laterally for guiding, the machine they
are connected at the outside by a rod L with a rock lever M of an oscil-
lating shaft N, which is turned forward and backward by a hand
wheel O, geared to it by worm wheels P. The rods of each side are
connected to the opposite ends of the rock lever and on opposite sides

page_text: 7th. The yokes D mounted on the wheels and pivoted to the body so
as to turn laterally for steering and turning the machine, substantially
as specified.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Fifteenth day of October,
in the year of our Lord One thousand cight hundred and seventy-
five.