IMPROVEMENTS IN TRACTION ENGINES.
Year: 1856

page_text: LETTERS PATENT to William Bray, of Folkstone, in the County of Kent,
Engineer, for the Invention of "IMPROVEMENTS IN TRACTION ENGINES.."
Sealed the 19th June 1857, and dated the 31st December 1856.
PROVISIONAL SPECIFICATION left by the said William Bray at the
Office of the Commissioners of Patents, with his Petition, on the
31st December 1856.
I, WILLIAM BRAY, of Folkstone, in the County of Kent, Engineer, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
TRACTION ENGINES," to be as follows:-
The wheels of traction engines adapted for ploughing or dragging weights
over soft ground have not sufficient hold upon the ground if constructed in
the ordinary manner. By my improvements I construct the wheels with
teeth or blades which enter the ground and obtain a firm hold. These teeth
are made to slide or move in and out by an eccentric or other mechanical
means, so that they clear themselves of the soil and are again ready to enter
the ground. The eccentric is capable of adjustment, so that the projection of
the teeth may be varied, and thus the wheel may at pleasure be made to act
like an ordinary wheel. This adjustment enables the wheels to run well upon
hard ground when required.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Bray in the Great Seal Patent Office on the
29th June 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
BRAY, of Folkstone, in the County of Kent, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirty-first day of December, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Bray, Her special licence that I, the said William Bray, my
executors, administrators, and assigns, or such others as I, the said William
Bray, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during tho
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, tho said William Bray
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 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 William Bray, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, reference being had to the accompanying Drawing, and to
the figures and letters marked thereon, that is to say:-
The wheels of traction engines adapted for ploughing or dragging weights
over soft ground have not sufficient hold upon the ground if constructed in
the ordinary manner. By mý improvements I construct the wheels with
teeth or blades which enter the ground and obtain a firm hold. These teeth
are made to slide or move in and out by an excentric or other mechanical
means, so that they clear themselves of the soil and are again ready to enter
the ground. The eccentric is capable of adjustment, so that the projection of
the teeth may be varied, and thus the wheel may at pleasure be made to act
like an ordinary wheel. This adjustment enables the wheels to run well upon
hard ground when required.

page_text: Figure 1 of the accompanying Drawing is a side view, partly in section,
of the wheel of a traction engine constructed according to my Invention;
Figure 2 is a plan, partly in section, of the same, and also shews a portion of
the engine shaft and one of the steam cylinders. The piston of the steam
cylinder A drives the crank shaft B, and another similar cylinder and piston
drive another crank on the same shaft, and placed at right angles to the first
crank, in the ordinary manner. The boiler and other details of the engine,
which are not shewn, are constructed in any of the ordinary or known manners.
Each end of the shaft B carries a pinion C, which drives a toothed wheel or
ring D fixed on the driving wheel, which is constructed in the following
manner:-E, E, E, are the spokes, of tec iron, which are fixed in the boss or
nave F and connected by rivets and by bracket plates G, G, to the trough-
shaped tire or ring, which consists of a cylindrical hoop H, with two side plates
or rings I, J, connected to it by rivets and angle irons, or otherwise; K, K, are
the teeth or blades, which slide between guide plates L, L, fixed in the tire.
These blades are connected by joints k, k, to rods M, M, which are jointed at
their ether ends m, m, to two rings N, N, encircling the eccentric O. One of
the rods Mi' is, however, connected rigidly to the rings N at m', so as to cause
the ring to revolve with the wheel. The eccentric O is fixed upon the shaft or
axle P, on which the boss or nave F is free to revolve. The axle P carries a
worm wheel Q geering into an endless screw R. By turning the screw R by
hand the axle P may be turned round, so as to bring the eccentric O into
different positions. When the eccentric is in the position shewn in the
Drawing, the blades or teeth K, K, are caused to protrude as they descend to
the ground by the revolution of the wheel, and to be drawn in as they ascend.
By this means the blades or teeth obtain a firm hold in the soft ground, which
enables the traction engine to drag the ploughs or waggons, or other articles
which may be attached to it. The broad hoop II obtains sufficient bearing
upon the ground to support the weight of the engine, and the side rings I, J,
prevent the earth from getting over the hoop H. The inner edges of the
rings I, J, may be connected by another hoop, so as to make the tire of the
form of a rectangular box instead of a trough; the earth cannot then get
into it. As the wheel revolves, the blades are cleared of the earth which
adheres to them as they pass over the upper part of the wheel, and they are
again protruded as they descend.
The extent to which the blades enter the ground may be varied by shifting
the eccentric, so as to cause the point of greatest protrusion to be at some
other point than the bottom of the wheel. By turning the eccentric half
round, the blades will be protruded at the top of the wheel, and will be drawn

page_text: into the wheel at the lower part. The engine can then travel along a hard
road or surface as though the wheels were of the ordinary construction.
The details of the machinery admit of variation. Thus the blades or
teeth K, K, may be either flat blades or a series of prongs or spikes. They may
also be connected rigidly to the rods M, M, without the intervention of the
joints k, k, and in that case the guide plates L, L, are dispensed with, or are
made to extend but a short distance within the hoop H, and are rather loosely
fitted to the blades, so as to allow of the slight angular motion which the blades
receive from the rods M, M. The wheel is shewn with one boss or nave and
one set of spokes, but it may be made with two bosses or naves and two sets of
spokes, one boss and set of spokes being placed on each side of the eccentric O.
Or, the eccentric may be placed outside the wheel instead of within it, and
the rods M, M, may then pass between the spokes. The eccentric and the
wheel Q may be mounted on a loose boss or collar, and the driving wheel may
be fixed on the axle, or both may be loose on the axle, which may then be
permanently fixed. A cam or a crank may also be used in lieu of the eccen-
tric. The crank pin, or the eccentric, or the cam may also be made adjustable,
so as to vary the eccentricity, or to bring it into a position concentric with the
wheel when required. Thus, if the parts be so proportioned that the blades may
not protrude when the eccentric is shifted into the concentric position, the
driving wheel may be employed to communicate motion to thrashing machines
or other machinery by means of a belt or strap passing round it, the engine
being blocked up or supported so that the wheel may not touch the ground.
As, however, it will generally be advisable to reduce the speed of the engine to
the driving wheel by means of the pinion C and wheel or toothed ring D,
I prefer to apply a separate pulley on the engine shaft B for communicating
motion to machinery when required. The pinion C is driven by a feather or
a square part on the shaft B, and is capable of being slidden along it so as to
draw it out or put it in geer with the wheel or ring D. The shaft B can thus
revolve independently of the driving wheels when required. Moreover, both
wheels can be driven while the engine is advancing in a straight line, and the
wheels will then tend to keep it to a straight course. On the other hand,
when it is required to turn or go round a curve, the wheel on the inner side or
smaller radius of the curve is disconnected, while the outer wheel is kept in
geer, and the engine is thus enabled to turn with facility. When the engine
is employed to drive a thrashing machine or other machinery, both wheels are
disconnected, and the eccentrics may be set so as to cause the blades to pro-
trude at the lower part, and assist in scotching the wheels, or preventing the
engine from shifting from its place. The wheels may be constructed so that

page_text: the blades or teeth are actuated by a spiral or other cam mounted on the
wheel itself. By turning or shifting this can on the wheel the blades may be
all protruded simultaneously when the engine has to travel over soft ground,
and they may be all withdrawn simultaneously when it has to travel on bard
ground. The engine may be constructed with two driving wheels and one or
two steering wheels. When it is supported on only three wheels, all the
wheels will bear upon the ground notwithstanding its being uneven. The
same effect may be obtained with four wheels, by supporting the engine on
the two driving wheels, and on a joint or pivot on the centre of the axle of
the two steering wheels, which are thus left free to accommodate themselves to
the inequalities of the surface of the ground. The engine may be made with
only one driving wheel constructed as herein-before described; but by employ-
ing two wheels with the connecting and disconnecting apparatus herein-before
described, the engine obtains a greater hold on the ground, and can also be
turned round in either direction with facility.
Having now described the nature of my Invention, and in what manner the
same is to be performed, I wish it to be understood that what I claim is, con-
structing traction engines with driving wheels with blades or teeth which are
capable of being protruded and withdrawn, as herein-before described.
In witness whereof, I, the said William Bray, have hereunto set my
hand and seal, this Twenty-fourth day of June, in the year of our
Lord One thousand eight hundred and fifty-seven.
WILLIAM BRAY. (L.S.)