IMPROVEMENTS IN ROAD LOCOMOTIVES
Year: 1869

page_text: LETTERS PATENT to Bristow Hunt, of No. '1, Serle Street, Lincoln's
Inn, in the County of Middlesex, Gentleman, for the Invention of
"IMPROVEMENTS IN ROAD LOCOMOTIVES."-A communication from abroad
by Jean Francois Cail, of the Firm of "J. F. Cail and Company,"
of Paris, France. .
Sealed the 31st August 1869, and dated the 9th March 1869.
PROVISIONAL SPECIFICATION left by the said Bristow Hunt at the
Office of the Commissioners of Patents, with his Petition, on the
9th March 1869.
I, BRISTOW HUNT, of No. 1, Serle Street, Lincoln's Inn, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN KUAD LOCOMOTIVES," (a communication
to me from abroad by Jean Francois Cail, of the Firm of J. F. Cail and
Company, of Paris, France) to be as follows:-
This improved locomotive is similar in its general arrangements to
the tender locomotives employed on railways. It is principally adapted
for the transport of goods at a slow speed, but by a modification con-
sisting of a simple change of wheels, easily performed, it can be trans-
formed into a passenger engine with double speed. It is carried on a
t

page_text: frame formed of longitudinal and transverse beams, and is suspended
by springs on the driving and guiding wheels. The boiler and water
tanks are completely independent of the mechanism and easily dis-
mounted. The mechanism placed under the boiler is within the longi-
tudinal frames and is provided with reversing gear and a break. The
furnace is placed at the same end as the fore carriage, which brings the
engineer and conductor together, they being both covered by the same
roof, and having within reach all the driving gear can help each other
if need be. This arrangement also has the advantage of enabling the
engine to be worked entirely by a single attendant, which in some cases
is useful. The water tanks and fuel bunks are carried by the steering
wheels, which alone sustain the variations of weight of those parts
when in use, whilst the driving wheels carry a load which never varies,
and this gives the engine a tractive power which is always constant on
the same kind of ground. The driving pistons of the two cylinders
placed between the longitudinal frames give motion by means of simple
connecting rods to the crank shaft, which carries a pinion gearing with
a toothed wheel, which is placed loosely on an intermediate shaft. The
toothed wheel carries round with it three bevil pinions, whose axes are
situated in the plane of their motion, round the intermediate shaft;
these three pinions gear between the two bevil wheels placed face to
face, one of the said wheels being keyed on the intermediate shaft,
which has a spur pinion keyed on one extremity, and the other bevil
wheel being attached to a long boss, which runs loosely on the inter-
mediate shaft and has a spur pinion attached to it at the other end
thereof. These two spur pinions give motion to the two driving wheels
(which are loose on the axle) by means of two rims of internal spur
teeth fixed to the arms of the wheels, and which can be easily replaced in
case of breakage. This arrangement keeps both wheels in constant
connection with the driving power and yet allows either wheel to
revolve faster than the other in passing round curves.
When the engine
runs in a direct line the three bevil pinions are merely carried round
the axis of the intermediate shaft, but do not revolve on their own axes,
but whenever one driving wheel has to pass round a curve of longer
radius than the other the pinions by revolving on their axes allow this
16 take place at the same time that both wheels are constantly in
connection with the driving power. It is intended to apply a coupling
box to this differential gearing, so as to be able to annul its effects and
take advantage of the adhesion of both wheels when desired. The

page_text: system of gearing above described is mounted on the axles, which
revolve in bearings carried by two chains keyed fast on the main axle;
these chains work in guides attached to the frame, and are connected
by forked rods to the suspending springs. The guiding wheels are
mounted loosely on an axle joined at its centre to a vertical shaft, which
receives the pressure of a suspension spring on a bearing at its upper.
end; a square part of this shaft passes through the boss of a segment
of a worm wheel, which derives its motion from a hand wheel, and by
means of the latter, which acts on the axle, the guiding wheels are
governed. A small pointer fixed on a shaft, which receives motion
from the segment, indicates the direction of the wheels of the fore
carriage to assist the conductor in guiding, the engine. The draw bar
is provided with a collar, in front of and behind which are placed
springs of india-rubber to annul the shocks of the traction, and also to
receive the pressure of the load in descending hills. The boiler is
similar to that of an ordinary locomotive engine, and is fed by a
"Giffard" injector, which may be supplemented at need by a pump
worked by the engine. A special steam pump may also be placed
within reach of the engineer to fill the water tank.
To convert the engine into a passenger engine, all that is required is
to remove the rims of internal spur teeth from the driving wheels and
to substitute rims of a smaller diameter with external teeth gearing
with the pinions at the ends of the intermediate shaft, so that the speed
of the driving wheels is about doubled.
To increase the adhesion and tractive force of the driving wheels I
propose to employ a tire formed of sections of wood with the end of the
grain outwards. The periphery of the wheel is provided with a dove-
tailed groove, the dovetail being cut away at one place where the blocks
of wood are introduced, and then slidden into their places, and then
secured by keys. This part of my Invention is also applicable to
locomotive engines to be used on railways for ascending steep inclines.
A second method of increasing the adhesion of the wheels consists
in throwing a jet of hot or cold water or steam on to the ground imme-
diately in front of the driving wheels, by means of a pump, injector, or
other apparatus.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Bristow Hunt in the Great Seal Patent Office on
the 8th September 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME. I. BRISTOW
HUNT, of No. 1, Serle Street, Lincoln's Inn, in the County of
Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of March, in the year of our
Lord One thousand eight hundred and sixty-nine, in the thirty-second
year of Her reign, did for Herself, Her heirs and successors, give and
grant unto me, the said Bristow Hunt, Her special licence that
I, the said Bristow Hunt, my executors, administrators, and assigns,
or such, others as I, the said Bristow Hunt, 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 ROAD LOCOMOTIVES."
(a communication to me from abroad by Jean Francois Cail, of the Firm
of JF. Cail and Company, of Paris, France) upon the condition
(amongst others) that I, the said Bristow Hunt, 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 1, the said Bristow Hunt, do hereby declare
the nature of the 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, and on reference being had to
the accompanying Sheets of Drawings, that is to say :-
This improved locomotive is similar in its general arrangement to the
tender locomotives employed on railways. It is principally adapted for
the transport of goods at a slow speed, but by a modification consisting
of a simple change of wheels, easily performed, it can be transformed
into a passenger engine with double speed. It is carried on a frame

page_text: formed of longitudinal and transverse beams, and is suspended by
springs on the driving and guiding wheels. The boiler and water tanks
are completely independent of the mechanism and easily dismounted.
The mechanism placed under the boiler is within the longitudinal
frames, and is provided with reversing gear and a break. The furnace is
placed at the same end as the fore carriage, which brings the engineer
and conductor together, they being both covered by the same roof, and
having within reach all the driving gear can help each other if need be.
This arrangement also has the advantage of enabling the engine to be
worked entirely by a single attendant, which in some cases is useful.
The water tanks and fuel bunks are carried by the steering wheels, which
alone sustain the variations of weight of these parts when in use; whilst
the driving wheels carry a load which never varies, and this gives the
engine a tractive power which is always constant on the same kind of
ground.
Such being the nature and object of the said Invention for "Improve-
ments in Road Locomotives," I will now proceed to describe more in
detail the manner in which the same is to be or may be performed or
carried into practical effect; and in order that the same may be distinctly
understood I have annexed hereunto two Sheets of Drawings illustrative
thereof, and have marked the same with figures and letters of reference
corresponding with those in the following explanation thereof, that is
to say-
In the annexed Drawings Figure 1 (Sheet 1) is a longitudinal section
of a road locomotive for goods constructed according to this Invention;
Figure 2 is a transverse half-section of the same through the line A, B,
in Figure 1; Figure 3 (Sheet 2) is a transverse half section through the
line C, D, in Figure 1; Figure 4 (Sheet 1) is a half plan view of the same,
and Figure 5 (Sheet 2) is a view of the differential movement gearing;
Figure 6 is an elevation, and Figure 7 a plan view of the bearing for the
driving shaft; Figure 8 is a transverse half section through the driving
axle showing the arrangement for a passenger locomotive; and Figures 9
and 10 are partial sectional views of a driving wheel with wooden tire.
With reference to the Drawings of the goods locomotive; the driving
pistons of the two cylinders C placed between the longitudinal frames D
give motion by means of simple connecting rods to the crank shaft E.
which carries a pinion F gearing with a wheel G, which is placed loosely
on an intermediate shaft H. The wheel G carries round with it three

page_text: bevil pinions K, Figure 5, whose axes are situated in the plane of their
motion round the shaft H; these three pinions gear with the bevil
wheels L, M, one of which (L) is attached to the spur pinion N, both
being loose on the shaft H; whilst the other one (M) and the pinion O
at the other end of the shaft are keyed on the said shaft. The two spur
pinions N and O give motion to the driving wheels P, which are loose
on the axle Q, by means of internal spur wheels R fixed on the arms of
the wheels. These wheels consist simply of toothed rings, which can
easily be replaced in the event of fracture. The arrangement of the
wheels G, L, M, and the three pinions K (Figure 5) constitutes a
differential system, the object of which is to maintain the driving wheels
constantly in connection with the motive power, notwithstanding the
differences in the speed of their motion, in passing round curves
according to the movement of the fore carriage. Thus when the engine
runs in a direct line the three bevil pinions K. are merely carried round
the axis of the intermediate shaft, but do not revolve on their own axes;
but whenever in passing round a curve the wheel (L, for instance,)
which acts on the driving wheel which passes round the larger curve
will have a greater velocity than the other wheel (M), the three
pinions K will revolve on their own axes, and thus allow of this dif-
ferential movement, an inversed effect being produced when the curve
is described in the opposite direction. A coupling box may be applied
to this differential gearing so as to give the power of annulling its
effects, and to take advantage of the adhesion of both wheels when
desired. The system of gearing above described is mounted on the axles
which revolve in bearings carried by two chairs S (Figures 6 and 7)
keyed fast on the main axle Q; these chairs work in guides T attached
to the frame, and are connected by forked rods X to the suspending
springs U and V. By this arrangement it will be easily seen that the
axles of the driving wheels are kept parallel and at invariable distances
from the axle Q by the two chairs S, and that the whole is mounted on
this axle. The oscillations due to the suspension of the boiler and a
great part of the mechanism are sustained solely by the connecting rods
as in ordinary locomotives. A screw break Y is applied at one end of
the crank shaft, and is put in operation by the hand wheel g within reach
of the engineer.

page_text: the bearing d the pressure of the suspension spring e. A square part
of this shaft passes through the boss of a segment of a worm wheel f
which receives its motion from the hand wheel g, and by means of this
latter the guiding wheels are governed. A small pointer i fixed on
a shaft which receives motion from the segment f indicates the direction
of the wheels of the fore carriage to assist the conductor in guiding
the engine.
The draw bar h is provided with three rings of india-
rubber j, j, j, two of which ; and j' serve to annul the shocks due
to the traction, and the third j' to receive the pressure of the load in
descending hills. Means of lubrication are applied to all the frictional
parts, they are however of the ordinary construction excepting those for
the axle boxes of the wheels, which consist of a syphon vessel / attached
to the screw nut m, the oil enters by the centre at the upper part of the
spindle n into a groove, whence it is distributed in the interior of the
axle box. The boiler is composed of a vertical cylindrical body form-
ing a steam chest in the upper part, and containing in the lower part
the furnace (the grating of which is circular) together with a horizontal
body in which the tubes are placed. The tubes are arranged on the
"Berendorff system" which allows of their being readily removed for
cleaning them and also the interior of the boiler. The steam is taken
from above the furnace in the dome and conducted by an interior tube o
into a regulator p placed near the chimney, whence it is distributed into
the cylinders by a valve worked by the handle q within reach of the
engineer. The chimney is provided with a hood k to prevent the
draught when stationary, and a grating in the smoke box prevents
the escape of sparks and cinders. The boiler is fed with water by a
"
Giffard injector" r, Figure 3, and if required a pump may be added
and driven by any convenient part of the moving mechanism, a special
steam pump may also be placed within reach of the engineer to fill
the water tank. The water tank S* may easily be dismounted as will
be seen on the plan, it is furnished with a basket filter t to retain any
impurities, the fuel bunks are placed at u on each side of the boiler;
they are independent of the water tank and can be dismounted
separately. The engine above described and shewn at Figures 1, 2, 3,
and 4 is specially designed for dragging trucks or waggons filled with
goods at a slow speed, and in order to convey passengers at a double
speed all that is required is to replace the internal gearing R fixed on
the wheels P by external toothed gearing R¹, as represented at Figure 8;
without in any way changing the other parts of the machine. This con-

page_text: trivance offers the advantage of being enabled to arrange a single engine
either for passengers or for goods, according to the service required, by
the simple changing of the driving wheels of which a pair for each case
must be kept in store. It has been found in practice that in many
cases a great amount of objection has been offered to the employment
of road locomotives in consequence of the adhesion of the wheels
varying with the nature of the soil and the state of the atmosphere,
and to such an extent that sometimes the traction resulting is not
sufficient to move the engine alone, and it has been sought to overcome
this difficulty by forming or placing projections on the tires, but this
means although efficacious in other respects damages the roads and
for that reason is rejected. Under these conditions and with iron tires
the use of locomotives on paved roads is almost impossible, and is very
frequently interrupted on macadamized roads. To obviate this great
inconvenience, and consequently to ensure a better service by the engines,
the Inventor proposes to obtain an increased adhesion by two methods
hereafter described.
The first means consists in replacing the iron tires by sections of wood
with the end of the grain outwards, the surface of which will give under
the most unfavorable conditions of soil or state of the atmosphere a
greater adhesion than iron, and will render possible the employment of
these engines in cases where hitherto they could not work advantageously.
Figures 8 and 9 represent in section a portion of a driving wheel
the tire of which is cased in wood. An examination of these Figures
will shew that the tire of the wheel has a conical groove formed therein
to receive blocks of hard wood A with the grain in a radial direction,
that is to say, with the end of the grain to the rolling surface. Το
place the blocks of wood in the groove of the tire the dovetail of the
latter is cut away at C in front of keys B to a sufficient width to allow
of the passage of a block, each block being entered at one of these
openings and then slidden into its place. They are held by series
between the keys B, which form so many partitions between which they
are tightened up by thin cones or wedges of metal driven between
them. The method of placing in these blocks of wood as well as, the
nature of the wood employed may be varied. This means of increasing
the adhesion is also applicable to the wheels of locomotives on railways
for ascending gradients,
"

page_text: The second method of increasing the adhesion of the wheels consists
in throwing a jet of hot or cold water or steam on to the ground imme-
diately in front of the driving wheels by means of a tube and nozzle
A', Figures 1 and 3, or by a pump, injector, or other apparatus.
In witness whereof, I, the said Bristow Hunt, have hereunto set my
hand and seal, this Eighth day of September, in the year of our
Lord One thousand eight hundred and sixty-nine.
BRISTOW HUNT. (L.S.)