IMPROVEMENTS IN LOCOMOTIVE ENGINES
Year: 1868

page_text: LETTERS PATENT to George Davies, of No. 1, Serle Street, Lincoln's
Inn, in the County of Middlesex, and No. 87, St. Vincent Street,
in the City of Glasgow, Civil Engineer and Patent Agent, for the
Invention of "IMPROVEMENTS IN LOCOMOTIVE ENGINES."-1 com-
munication from abroad by Meliton Martin, of Madrid, Civil
Engineer.
Sealed the 3rd November 1868, and dated the 6th July 1868.
PROVISIONAL SPECIFICATION left by the said George Davies at the
Office of the Commissioners, of Patents, with his Petition, on the
6th July 1868.
I, GEORGE DAVIES, of No. 1, Serie Street, Lincoln's Inn, in the
County of Middlesex, and No. 87, St. Vincent Street, in the City of
Glasgow, Civil Engineer and Patent Agent, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN LOCOMOTIVE ENGINES," being
a communication to me from abroad by Meliton Martin, of Madrid,
Civil Engineer, to be as follows:-

page_text: the train to travel over the heaviest gradients. The machinery may be
composed of a rotary steam engine, two shafts, and two horizontal
wheels, and the frame, screws, and springs to produce any required
amount of pressure on the central rail. This apparatus can be placed
either on the locomotive or on its tender.
I shall now describe the latter arrangement, by which the nature of
this Invention will be more readily understood, and which offers many
advantages over the other.
Figs. 1, 2, 3, 4, 5, and 6 represent the form of cylinder adopted in
the improved locomotive, which cylinder is traced by the intersection
of two circles of equal diameter, whose centres are placed at a distance
greater than the radius but less than the diameter of the said circles.
The cylinder is thus formed by two lateral and parallel bores of equal
diameters, but penetrating one into the other. Two shafts pass through
the centres of the bores carrying each a piston having the form of an
annular segment. Concentric with the shafts are mounted two cylin-
drical bodies recessed in that part of their circumference nearest each
other, so as to leave an annular space around the shafts wherein the
pistons P, P', (Figs. 1 to 6) may run freely. In order to communicate to
the shafts the movement of these pistons they are cast or forged on a
circular disc (Figs. 7, 8, 9,) in such a manner that each piston is jointed
to its disc by the annular segment a, b, c, d, Fig. 9.
Figs. 7, 8, and 9 are isometrical views of the pistons with their discs,
under each of which is placed a toothed wheel D, R, secured in position
by eight cogs or teeth cast on the face of either the wheel or the disc, so
as to fit tightly into eight mortices cut out on the opposite face of the
disc or wheel. Let us now suppose the two pistons keyed on their parallel
shafts introduced into the cylinder in the position indicated in Fig. 1, and
the toothed wheels also fixed on the shaft under the discs so as to work
into each other, the distance travelled by one of the pistons in one
direction will be exactly equal to the distance travelled by the other
in the opposite direction. Let steam be admitted from a boiler into
the cylinder at A, the pressure on the face at m, n, will propel the left-
hand piston in one direction, and the right-hand piston will follow the
movement in the contrary direction, thus occupying the positions shown

page_text: in Figures 2, 3, 4, 5, and 6 successively. When the pistons reach the
position shown in Fig. 6 steam will escape at S if there be another
opening or tube placed at this point of the intersection of the two
circles forming the cylinders; but before arriving at this point the
pistons have occupied the position shewn in Fig. 5, and the steam
entering at A has been cut off on the left hand, and begun to exert
its pressure on the face b, f, of the right-hand piston. The motion of
each shaft will thus be uniformly maintained in the same direction so
long as steam is admitted at A, and the pressure will be exerted
alternately on both pistons without dead point or loss of speed or
power. To reverse the notion the steam may be cut off at A and
admitted at S; the pistons will then move in the opposite direction,
and the steam escape at A. The power of the rotary engine is applied
(especially on heavy gradients) to horizontal wheels working in contact
with a central rail.
.
Figs. 10, 11, 12, and 13 represent in plan and section an application
of my Invention to a locomotive tender. The rotary engine occupies
the centre of the tender, to the frame of which it is firmly secured, so
that all the other parts of the apparatus may be placed below the floor
plate. As is seen in Fig. 11 both the shafts of the engine project
vertically downwards and carry at their extremities two horizontal
wheels R, R', pressing closely against the central rail of the line and
at a certain height above the upper surfaces of the side rails, say from
ten to twelve inches. When the pistons are set in motion the
shafts A, A', turn with their horizontal wheels in contrary directions
as already described, and the adherence of the said wheels on the
opposite sides of the central rail carries the train either forward or
backward, the degree of traction being proportioned to the pressure
exerted on the said central rail.
The apparatus by which the required adherence of the horizontal
wheels is produced is constructed as follows:-Two strong iron plates
C, C, C¹, C¹, Fig. 15, are securely fixed in a vertical position under
the space between the two axles of the tender and carry horizontal
slides C, C, C', C', Fig. 16, provided on each side of the centre line
with four strong beams V, V', and W, W₁, which rest and slide parallèl
to each other. The two central beams V, V', carry the plumber blocks
and brasses which maintain the vertical shafts in their required position.

page_text: Between these central beams and the outside beams W, W', are placed
eight or more volute springs r, r, r, r, calculated to transmit the required
pressure to the central wheels. The inside beams V, V, can only slide
to a limited extent between the stops s, s. The outside beams W, W',
are connected at their ends by two powerful screws P, O, F, G, having
a right-hand thread at one end and a left-hand thread at the other;
thus when these screws are set in motion they bring the outside beams
toward the central rail or remove them from it with mathematical
precision; in so doing the outer beams press against the springs, which
thus exert a given pressure against the inner beams, and thereby on the
vertical shafts and their horizontal wheels. In order to bring the
compressing gear within reach of the driver an endless screw X, Y,
(Fig. 15), placed horizontally along the side of the tender, works in two
toothed pulleys N, N', fixed on the ends of the compressing screws, and
by means of two bevel wheels f, h, of the proper diameters and the
lever I the pressure can be regulated by hand while the engine is
running. This mode of producing adherence on the central rail is
simple and efficient, the different parts of the arrangement being
situated on the same plane, and the screws working in the best and
most advantageous position. The vertical shafts being made of steel,
and the number and size of the volute springs properly calculated, any
amount of pressure may be thus brought to bear on the central rail
which if necessary may also be made of steel. It will be remembered
that the inner beams V, V', can only slide between the points s, s,
Fig. 16. This indicates that the vertical shafts A, A', Figs. 11 and 12,
may incline slightly either to one or other side, a point of considerable
importance when the horizontal wheels are brought to bear on the central
rail; an universal joint at J, J', Fig. 11, is therefore absolutely
necessary, and I shall now describe the one represented in Figures 12
and 14. As above stated the rotary motion of the pistons is com-
municated to the shafts A, A', (Fig. 12) upon which the toothed wheels
are fixed, and whose upper ends project above the cylinders through an
ordinary stuffing box. Each shaft is composed of two parts, one of
which forming its upper half has a diameter proportioned to the power
of the engine; the other half is of much larger diameter and terminates
at S (Figs. 12, 13, and 14) in a perfect sphere traversed by two cylin-
drical and projecting rods m, m, m, at right angles to each other.
M, N, O, P, (Fig. 14) are four brasses turned to fit on the surface of

page_text: the sphere and having each a circular bore X, X, into which passes
the projecting hubs. These bores in the brasses are of a diameter
slightly larger than the hubs of the sphere, so that when the brasses M,
P, N, O, are applied to the sphere it may describe a concentric motion
round its centre, thereby allowing the under half of the shafts A, A',
to assume a slightly inclined position in all directions. The brasses M,
N, O, P, Fig. 14, have all projecting tenons T, T, T, on their upper
surface, and are turned externally to a true cylindrical form. Thus
set and adjusted the tenons T, T, fit into grooves formed on the under
surface of the toothed wheel of the rotary engine, and the under cover
of the cylinder C, H, L, I, (Fig. 12) is brought to position and screwed
down. The pistons with their toothed wheels being set in motion the
cylinder formed by the brasses of the sphere S (Figs. 12 and 13) will
also revolve, and the sphere itself with the shaft A must also turn even
if it forms an angle with the upper half G, S, of the corresponding
shaft; of course the inclination of the shafts A, A', (Figs. 11 and 12)
must, as before stated, be kept within very small limits between the
stops s, s, (Fig. 16). The arrangement adopted for the admission and
eduction of steam is represented in Fig. 13. The steam admitted at V
(Fig. 10) fills the pipe M, M, half round the cylinder. At the points of
intersection are two steam chambers also of a cylindrical form A, A¹;
(Fig. 10) each divided into two parts by two circular regulators placed
at A and A¹. A shaft working in a stuffing box carries the moveable
parts of the regulators in such a manner that when the upper regulator
on one side or chamber is opened the lower regulator is closed, and
vice versa (Fig. 13). Now in supposing both the shafts of the steam
chambers to be so placed that the upper regulator of the left-hand
side be opened and the right-hand one closed, the left-hand lower
regulator will then be closed and the right-hand one open, as in Fig. 13.
Steam entering through the top left-hand regulator must penetrate
into the cylinder, move the pistons, and pass through into the right-
hand steam chamber; there finding the top regulator shut and the
bottom one open it will escape through the pipe. It should be observed
that the two shafts of the steam chambers are provided at their upper
end with a lever at right angles R, R', and that the extremities of these
In this case the
two levers may be joined by a connecting rod B, B.
driver can reverse the motion of the engine by pulling or pushing the
connecting rod so as to turn the axle by a quarter of a revolution in one
or the other direction. The top regulator of each steam chamber can,

page_text: 13.
if so desired, be fixed on a tube concentric with its axle, as in Fig. 13,
this tube to move round with the said axle so long as its lever R, R'
is fixed on the main lever by means of a spring and notch s, s, Fig.
With such arrangement the driver will be able after he has opened
the steam inlet to lift the tube lever, disengage its end from the notch
on the main lever, and work it independently of the outlet regulators,
so as to regulate the steam opening and allow more or less steam to
enter the cylinder. Any other arrangement to admit to and cut off
steam from the cylinder will be equally sufficient.
I have now to describe the arrangement by which is effected the heat-
ing of water in the tender or the partial condensation of steam. The
outlet pipe P, X, N, F, is carried under the tender axle through the
tank and projects into a closed chamber F, F, constructed over the
back part of the water space. This condensing chamber is surmounted
by a chimney M, Fig. 13, at the foot of which is mounted a light valve,
the pressure of which on the steam within the chamber but slightly
exceeds that of the atmosphere. Two pumps P, P, (Fig. 10) supply
the cold water from the bottom of the tender and disperse it into the
condensing chamber so as to produce the partial condensation of the
steam escaping from the cylinder. So long as the pressure in the
cylinder remains below that of the atmosphere, or very little above it,
the valve O (Fig. 13) will remain closed, but when the water becomes
heated and condensation no longer takes place the pressure inside the
chamber will raise the valve O and the steam will escape into the open
air; back pressure on the pistons therefore can never be very consider-
able, and a great economy can thus be realised. The rotary engine
above described with its compression gear and adherence mechanism
may also as before stated be mounted on the locomotive itself. The
steam can also be made to enter into a second cylinder, either above,
below, or alongside of the main cylinder so as to increase the power
of the engine or to profit by the expansion of steam on the Wolf principle
or otherwise. It is also evident that the number of cylinders and hori-
zontal wheels may be increased if desired.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Davies in the Great Seal Patent Office on
the 1st December 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
DAVIES, of No. 1, Serle Street, Lincoln's Inn, in the County of Mid-
dlesex, and No. 87, St. Vincent Street, in the City of Glasgow, Civil
Engineer and Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of July, in the year of our
Lord One thousand eight hundred and sixty-eight, in the thirty-second
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said George Davies, Her special licence that I, the
said George Davies, my executors, administrators, and assigns, or such
others, as I, the said George Davies, 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 "IMPROVEMENTS IN LOCOMOTIVE
ENGINES," a communicat on to me from abroad by Meliton Martin,
of Madrid, Civil Engineer, upon the condition (amongst others)
that I, the said George Davies, 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 George Davies, 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, reference being had to the Figures of the accom-
panying Drawings, and to the letters marked thereon, that is to
say:
This Invention consists in the direct application to locomotives of one
or more rotary engines giving motion to one or more pairs of horizontal

page_text: wheels, which pressing against the vertical faces of a central rail
enable the train to travel over the heaviest gradients. The machinery
may be composed of a rotary steam engine, two shafts, and two hori-
zontal wheels, and the frame, screws, and springs to produce any
required amount of pressure on the central rail. This apparatus can
be placed either on the locomotive or on its tender.
I shall now describe this latter arrangement, by which the nature
of the Invention will be more readily understood, and which offers
many advantages over the other.
Figures 1, 2, 3, 4, 5, 6,. of the Drawings represent the form of
cylinder adopted in the improved locomotive, which cylinder is traced
by the intersection of two circles of equal diameter, whose centres are
placed at a distance greater than the radius but less than the diameter
of the said circles. The cylinder is thus formed by two lateral and
parallel bores of equal diameters, but penetrating one into the other.
Two shafts pass through the centres of the bores carrying each a piston
having the form of an annular segment. Concentric with the shafts
are mounted two cylindrical bodies recessed in that part of their circum-
ference nearest each other, so as to leave an annular space around the
shafts wherein the pistons P, P', (Figs. 1 to 6) may run freely. In
order to communicate to the shafts the movement of these pistons they
are cast or forged on a circular disc (Figs. 7, 8, 9) in such a manner
that each piston is joined to its disc by the annular segment a, b, c, d,
Fig. 9.
Figures 7, 8, 9, are isometrical views of the pistons with their discs,
under each of which is placed a toothed wheel D, R, secured in posi-
tion by eight cogs or teeth cast on the face of either the wheel or the
disc, so as to fit tightly into eight mortices cut out on the opposite face
of the disc or wheel. Let us now suppose the two pistons keyed on
their parallel shafts introduced into the cylinder in the position indicated
in Fig. 1, and the toothed wheels also fixed on the shaft under the
discs so as to work into each other, the distance travelled by one of the
pistons in one direction will be exactly equal to the distance travelled
by the other in the opposite direction. Let steam be admitted from a
boiler into the cylinder at A, the pressure on the face m, n, will propel
the left-hand piston in one direction, and the right-hand piston will
follow the movement in the contrary direction, thus occupying the
positions shewn in Figs. 2, 3, 4, 5, 6, successively. When the pistons
reach the positions shewn in Fig. 6 steam will escape at S if there be

page_text: another opening or tube placed at this point of the intersection of the
two circles forming the cylinders; but before arriving at this point the
pistons have occupied the position shewn in Fig. 5, and the steam
entering at A has been cut off on the left hand and begun to exert its
pressure on the face b, f, of the right-hand piston. The motion of each
shaft will thus be uniformly maintained in the same direction so long as
steam is admitted at A, and the pressure will be exerted alternately on
both pistons without dead point or loss of speed or power. To reverse
the motion the steam may be cut off at A and admitted at S; the pistons
will then move in the opposite direction and the steam escape at A.
The power of this rotary engine is applied especially on heavy gradients
to horizontal wheels working in contact with a central rail.
Figures 10, 11, 12, 13, represent in plan and section an application
of the Invention to a locomotive tender. The rotary engine occupies
the centre of the tender, to the frame of which it is firmly secured, so.
that all the other parts of the apparatus may be placed below the floor
plate. As is seen in Fig. 11 both the shafts of the engine project verti-
cally downwards and carry at their extremities two horizontal wheels
R, R, pressing closely against the central rail of the line and at a
certain height above the upper surfaces of the side rails, say from ten
to twelve inches. When the pistons are set in motion the shafts A, A¹,
turn with their horizontal wheels in contrary directions as already
described, and the adherence of the said wheels on the opposite sides
of the central rail carries the train either forward or backward, the
degree of traction being proportioned to the pressure on the said central
rail.
The apparatus by which the required adherence of the horizontal
wheels is produced is constructed as follows:-Two strong iron plates
C, C, C, C¹, Fig. 15, are securely fixed in a vertical position under the
space between the two axles of the tender and carry horizontal slides
C, C, C, C, Fig. 16, provided on each side of the centre line with four
strong beams V, V', and W, W', which rest and slide parallel to each
other. The two central beams V, V', carry the plummer blocks and
brasses which maintain the vertical shafts in their required position.
Between these central beams and the outside beams W, W', are placed.
eight or more volute springs r, r, r, r, calculated to transmit the
required pressure to the central wheels. The inside beams V¹, can
only slide to a limited extent between the stops s, s. The outside beams

page_text: W, W', are connected at their ends by two powerful screws P, O, F, G,
having a right-hand thread at one end and a left-hand thread at the other;
thus when these screws are set in motion they bring the outside beams
towards the central rail or remove them from it with mathematical pre-
cision; in so doing the outer beams press against the springs, which thus
exert a given pressure against the inner beams, and thereby on the
vertical shafts and their horizontal wheels. In order to bring the com-
pressing gear within reach of the driver an endless screw X, Y,
Fig. 15, placed horizontally along the side of the tender, works in two
toothed pullies N, N¹, fixed on the ends of the compressing screws, and
by means of two bevel wheels f, h, of the proper diameters and the
lever I the pressure can be regulated by hand while the engine is
running. This mode of producing adherence on the central rail is
simple and efficient, the different parts of the arrangement being situated
on the same plane, and the screws working in the best and most advan-
tageous position. The vertical shafts being made of steel, and the
number and size of the volute springs properly calculated, any amount
of pressure may be thus brought to bear on the central rail, which if
necessary may also be made of steel. It will be remembered that the
inner beams V, V', can only slide between the points s, s, (Fig. 16);
this indicates that the vertical shafts A, A', Figs. 11, 12, may incline
slightly either on one or other side, a point of considerable importance
when the horizontal wheels are brought to bear on the central rail;
an universal joint at J, J', Fig. 11, is therefore absolutely necessary,
and I shall now describe the one represented in Figs. 12 and 14. As
above stated the rotary motion of the pistons is communicated to the
shafts A, A', Fig. 12, upon which the toothed wheels are fixed, and
whose upper ends project above the cylinders through an ordinary
stuffing box. Each shaft is composed of two parts, one of which form-
ing its upper half has a diameter proportioned to the power of the
engine; the other half is of much larger diameter and terminates at S,
Figs. 12, 13, 14, in a perfect sphere traversed by two cylindrical and
projecting rods m, m, m, at right angles to each other. M, N, O, P,
Fig. 14, are four brasses turned to fit on the surface of the sphere and
having each a circular bore X, X, into which pass the projecting hubs.
These bores in the brasses are of a diameter slightly larger than the
hubs of the sphere, so that when the brasses M, P, N, O, are applied
to the sphere it may describe a concentric motion round its centre,
thereby allowing the under half of the shaft A, A', to assume a slightly

page_text: inclined position in all directions. The brasses M, N, O, P, (Fig. 14)
have all projecting tenons T, T, T, on their upper surface, and are
turned externally to a true cylindrical form. Thus set and adjusted
the tenons T T, fit into grooves formed on the under surface of the
toothed wheel of the rotary engine, and the under cover of the cylinder
C, H, L, I, Fig. 12, is brought to position and screwed down. The
pistons with their toothed wheel being set in motion the cylinder formed
by the brasses of the sphere S, Figs. 12, 13, will also revolve, and the
sphere itself with the shaft A must also turn even if it form an angle
with the upper half G, S, of the corresponding shaft; of course the
inclination of the shafts A, A', Figs. 11, 12, must, as before stated, be
kept within very small limits between the stops s, s, Fig. 16. The
arrangement adopted for the admission and eduction of steam is repre-
sented in Fig. 13. The steam admitted at V, Fig. 10, fills the pipe
M, M, half round the cylinder. At the points of intersection are two
steam chambers also of a cylindrical form A, A', Fig. 10, each divided
into two parts by two circular regulators placed at A and A'. A shaft
working in a stuffing box carries the moveable parts of the regulators in
such a manner that when the upper regulator on one side or chamber
is opened the lower regulator is closed, and vice versa (see Fig. 13). Now
in supposing both the shafts of the steam chambers to be so placed that
the upper regulator of the left-hand side be opened and the right-hand
one closed, the left-hand lower regulator will then be ciosed and the
right-hand one opened, as in Fig. 13. Steam entering through the top
left-hand regulator must penetrate into the cylinder, move the pistons,
and pass into the right-hand steam chamber; there finding the top
regulator shut and the bottom one open it will escape through the pipe.
It should be observed that the two shafts of the steam chambers are pro-
vided at their upper end with a lever at right angles R, R', and that
the extremities of these two levers may be joined by a connecting rod
B, B. In this case the driver can reverse the motion of the engine by
pulling or pushing the connecting rods so as to turn the axles by a
quarter of a revolution in one or the other direction. The top regu-
lator of each steam chamber can, if so desired, be fixed on a tube con-
centric with its axle, as in Fig. 13, this tube to move round with the
said axle so long as its lever R, R', is fixed on the main lever by means
of a spring and notch s, s, Fig. 13. With such an arrangement the
driver will be able after he has opened the steam inlet to lift the tube

page_text: lever, disengage its end from the notch on the main lever, and work it
independently of the outlet regulators, so as to regulate the steam open-
ing and allow more or less steam to enter the cylinder.
Any other
arrangement to admit to and cut off steam from the cylinder will be
equally efficient.
I have now to describe the arrangement by which is effected the heat-
ing of water in the tender or the partial condensation of steam. The
outlet pipe P, X, N, F, is carried under the tender axle through the
tank and projects into a closed chamber F, F, constructed over the
back part of the water space. This condensing chamber is surmounted
by a chimney M, Fig. 13, at the foot of which is mounted a light valve,
the pressure of which on the steam within the chamber but slightly
exceeds that of the atmosphere. Two pumps P, P, Fig. 10, supply the
cold water from the bottom of the tender and disperse it into the con-
densing chamber so as to produce the partial condensation of the steam
escaping from the cylinder. So long as the pressure in the chamber
remains below that of the atmosphere, or very little above it, the valve
O, Fig. 13, will remain closed, but when the water becomes heated and
condensation no longer takes place the pressure inside the chamber will
raise the valve O and the steam will escape into the open air; back
pressure on the pistons therefore can never be very considerable, and a
great economy can thus be realised. The rotary engine above described
with its compression gear and adherence mechanism may also as beforc
stated be mounted on the locomotive itself. The steam can also be
made to enter into a second cylinder either above, below, or alongside of
the main cylinder so as to increase the power of the engine or to profit
by the expansion of steam on the Wolff principle or otherwise. It is
also evident that the number of cylinders and horizontal wheels may be
increased if desired.
Having thus described the nature of the said improvements, and the
manner in which the same are or may be carried into effect, I would
have it understood that I do not confine myself to the precise details
of construction and general arrangement herein laid down, as these may
obviously be modified according to circumstances without deviating from
the principle or main features of the Invention; but what I claim and
desire to protect by Letters Patent is, the application to locomotives of
one or more rotary engines acting on one or more pairs of horizontal

page_text: wheels so arranged as to exert a variable pressure on a central rail in
manner and for the purpose substantially as herein specified and shewn
in the Figures of the accompanying Drawings.
In witness whereof, I, the said George Davies, have hereto set my
hand and seal, this Twenty-seventh day of November, in the year
of our Lord One thousand eight hundred and sixty-eight.
GEORGE DAVIES. (L.S.)