IMPROVEMENTS IN STEAM ENGINES
Year: 1852

page_text: LETTERS PATENT to Frederick Joseph Bramwell, of Millwall,
in the County of Middlesex, Engineer, for the Invention of
"IMPROVEMENTS IN STEAM ENGINES."
Sealed the 31st May 1853, and dated the 17th December 1852.
PROVISIONAL SPECIFICATION left by the said Frederick Joseph
Bramwell at the Office of the Commissioners of Patents, with
his Petition, on the 17th December 1852.
I, FREDERICK JOSEPH BRAMWELL, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN STEAM ENGINES" to be as
follows:
The Invention relates to the construction and modes of working
the valves, and to the heating of the cylinders of steam engines.
I give motion to the slide valves of steam engines by means of
two excentrics, one of which is placed within and carries the other.

page_text: in
One excentric is driven at a different velocity to the other, and
generally I prefer to drive it at three times the velocity of the other
excentric. A rod being connected to a ring round the outer ex-
centric, gives motion to the slide valve in the usual manner. By
employing two excentrics revolving at different velocities in this
manner, the valve receives a motion compounded of the two excen-
tric movements, by which means the valve is caused to vary
velocity, and to pause or retrograde slightly in certain parts of its
course, by which means the admission of steam to the steam cylinder
may be more advantageously regulated and adjusted than by the
ordinary valve motion with one excentric. The excentrics may be
made adjustable as regards their length of stroke and position. In
lieu of excentrics cranks may be used for the same purpose. By this
means the valve may be so adjusted as to cause the steam to expand
in the cylinder, and thus to produce an economy of both steam and
fuel. The expansion may also be altered by adjusting the positions
of the various parts. In this way the power may be varied, which
is of advantage for vessels which are exposed to the vicissitudes of
wind and weather, as well as in many other cases. Another mode of
arranging the valves consists in applying a cylindrical valve having
a double or compound motion, consisting of a reciprocating longitu
dinal motion in the direction of its axis, and a reciprocating or con-
tinuous rotary motion upon its axis, the passages being arranged to
correspond, so that the opening and closing of them may be properly
regulated. In lieu of the cylindrical valve, a similar result may be
produced with a flat valve by giving it both a longitudinal and trans-
verse motion, or a rectilinear and rotary motion, or two curvilinear
motions. In these various arrangements, the motion or motions may
be given by excentrics, cranks, cams, levers, or otherwise, as may be
found convenient. I heat the cylinders of steam engines by surround-
ing the cylinder with a jacket or casing, or pipes, in which hot oil or
hot liquid metal or alloy, or hot water under pressure, is caused to
circulate. The liquid may be heated by passing it through pipes
exposed to the action of fire. By this means the cylinder may be
heated to a higher temperature than the steam in the boiler which

page_text: supplies it, which is not the case when the ordinary steam jacket
supplied with steam direct from the boiler is employed.
SPECIFICATION in pursuance of the conditions of the Letters
Patent, filed by the said Frederick Joseph Bramwell in the
Great Seal Patent Office on the 17th June 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
FREDERICK JOSEPH BRAMWELL, of Millwall, in the County of Middle-
sex, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of December, in the
year of our Lord One thousand eight hundred and fifty-two, in the
sixteenth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Frederick Joseph Bramwell,
Her special licence that I, the said Frederick Joseph Bramwell, my
executors, administrators, and assigns, or such others as I, the said
Frederick Joseph Bramwell, 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 STEAM ENGINES,"
upon the condition (amongst others) that I, the said Frederick
Joseph Bramwell, by an instrument in writing under my hand and
seal, 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 Frederick Joseph Bramwell,
do hereby declare the nature of the said Invention, and in what

page_text: manner the same is to be performed, to be particularly described and
ascertained in and by the following statement thereof, reference
being had to the accompanying Drawings, and to the letters and
Figures marked thereon (that is to say):
The Invention relates to the construction and mode of working
the valves, and also to the heating of the cylinders of steam engines.
Figure 1, Sheet I, of the accompanying Drawings, is a front view,
partly in section, of a steam engine fitted with valve gear, con-
structed according to my Invention. Figure 2, is a back view of the
same; and Figure 3, is a plan of the same. Figures 4, 5, 6, 7, 8, and 9,
Sheet II, are diagrams, shewing various positions of the valve gear
with the corresponding positions of the piston of the engine. The
same letters refer to the same parts in each Figure. A, is the
cylinder; B, is the piston, with its rod C, and connecting rod D,
jointed to the crank E, on the main shaft F; G, is the slide valve,
the rod H, of which, is connected by the rod I to the lever J; K,
is another lever fixed on the same, spindle as the lever J, and
driven by the excentric rod L, which receives its motion from the
excentric M. This excentric, however, is not fixed upon the main
shaft F, but is mounted on a smaller excentric N, which turns loose
upon the main shaft F; O, is a toothed wheel fixed on the main
shaft F, and driving the pinion P, which runs loose upon the pin Q;
R, is a wheel fixed to the pinion P, and driving the pinion S,
which runs loose upon the shaft F, and is fixed to the small excen-
tric, N. The wheels and pinions O, P, R, S, are so proportioned,
that the small excentric N, makes three revolutions while the main
shaft F, makes one revolution. This may be effected by making
the wheel O, twice the diameter of the pinion P, and the wheel
R, one and a half times the diameter of the pinion S. The large
excentric M, carries a pin m, which is driven by the segmental
piece T, which is fixed on the main shaft, so that the large excentric
M, makes one revolution while the main shaft F, makes one revo-
lution, and the small excentric M, makes three revolutions. The
excentric rod L, thus receives a motion compounded of the motions
of the two excentrics. The curved and looped red lines in Figures

page_text: 4, 5, 6, 7, 8, and 9, shew the path or course traversed by the centre
of the large excentric M, which regulates the motion of the excen-
tric rod L, and the valve G. The curved path described by the
centre of the large excentric M, approximates to the form of an epi-
cycloid.
The effect of this arrangement of valve gear is shewn by the
Figures or Diagrams on Sheet II. Thus, in Figure the crank E,
has turned the centre, and the piston B, has begun to ascend, and
it will be seen that the slide valve has risen so as to open the lower
port or passage leading to the bottom of the cylinder. In Figure
5, the piston has performed about one quarter of its stroke, and the
slide valve has descended sufficiently to cut off the steam from the
lower part without interfering with the escape of the steam from
the top of the cylinder through the upper port and the slide valve,
to the eduction passage. The slide valve G, is made sufficiently
long for this purpose, as shewn in the Drawing.
In Figure 6, the slide valve has descended still farther, but with-
out affecting the course of the steam. In Figure 7, the valve has
ascended a little; and in Figure 8, it has again descended a little,
but still without affecting the course of the steam.
The piston B, has, in the meantime, ascended from the position
shewn in Figure 5, to that shewn in Figure 8, while the valve may
be considered to have paused in its motion, or remained stationary,
as its slight motion does not affect the course of the steam.
As the motion of the piston still continues, the valve G, rapidly
descends, and puts the bottom of the cylinder in connection with
the eduction passage and also admits the steam through the upper
port to the top of the cylinder, as shewn in Figure 9. A similar
series of motions takes place during the descent of the piston.
The steam is thus worked expansively without the necessity of
employing a separate expansion valve. The degree of expansion
may be varied when required by altering the position of the pin Q.
Figures 1, 2, and 3, show an arrangement which may be employed
to vary the expansion, while the engine is in motion. For this
purpose, the pin Q, is mounted on a worm wheel or segment of

page_text: a worm wheel U, turning loose upon the main shaft F, or upon a
bearing concentric with it. V, is an endless screw gearing into the
segment U, and provided with a handle v, by turning which the
position of the pin Q, is altered, and a corresponding alteration is
made in the position of the curved or epicycloidal path of the centre
of the large excentric M. The valve will then cut off the steam at
a different part of the stroke.
To reverse the engine the screw V, is turned to such an extent
as to reverse the relative position of the loops of the epicycloidal
figure. With regard to the excentric rod L, the segmental piece T,
performs a portion of a revolution, without moving the excentric
M, until it comes in contact with the opposite side of the pin m, and
it then drives the excentric M, in the opposite direction. The main
shaft F, will then revolve in the opposite direction to that indicated
by the arrows, and the pause in the motion of the valve will take
place as before.
Figure 10, Sheet III, represents an epicycloidal valve gear, such
as is described in the Specification of former Letters Patent granted
to me, and bearing date at Westminster the Twentieth day of
November, One thousand eight hundred and fifty-one; and I have
introduced this valve gear for the purpose of showing the applica-
tion to such valve gear of a similar mode of varying the expansion to
that herein-before described in reference to Figures 1, 2, and 3. f, is
the opposite extremity of the main shaft to that at which the main
crank of the engine is fixed. The position of the main crank is in-
dicated by the line E, and that of the connecting rod, by the line D;
or the shaft F, may be a separate shaft, driven by toothed wheels or
otherwise, at the same speed as the main shaft. O, is a fixed or
stationary wheel, and S, is a pinion of half the diameter of the wheel
Q; this pinion is mounted on a short shaft or spindles, which is
carried by the crank M, fixed on the shaft f. The spindle s, carries
a crank N, to the pin of which is jointed the connecting rod L,
which drives the valve as in the other Figures herein-before described.
The pin of the crank N, describes an epicycloidal curve as shewn
by the red line, and the pause in the motion of the valve takes place

page_text: as in the arrangement first herein-before described. So far this ar-
rangement is similar to one of those described in the Specification of
the aforesaid former Letters Patent.
The expansion is varied by making the wheel O, capable of turn-
ing on the shaft f, or on a bearing concentric with it, so that its
position may be adjusted by means of the worm wheel U, screw
V, and handle v. The crank M, may also be made loose upon the
shaft f, with a sufficient amount of play to admit of the engine
being reversed in a similar manner to that first herein-before de-
scribed. The rest of the engine is constructed in a similar manner
first herein-before described.
Figure 11, shews another epicycloidal valve gear very similar to
that shewn in the Figure 10, and also described in the Specification
of the aforesaid former Letters Patent, except in as far as regards
the mode of varying the expansion. In this arrangement the sta-
tionary wheel O, is made with internal teeth, and the pinion S, is
one fourth of the diameter of the wheel O. The pin of the crank N,
describes an epicycloidal figure with four loops, as shewn by the red
line. The rod L, communicates the motion to the valve, which pauses
in its motion as in the other arrangements herein-before described.
The expansion is varied by varying the position of the wheel O, by
means of the worm wheel U, screw V, and handle v, as in the ar-
rangements shewn in Figure 10, and the engine is reversed in a
similar manner. In all these arrangements a pinion and toothed
wheel may be substituted for the screw V, and worm wheel U, or
the requisite motion may be given by any other suitable means.
Figure 12, shows another arrangement of valve gear. F, is the
main shaft, which carries an excentric M, giving motion to the rod
H, by means of the excentric rod L. The rod H, is guided by a
stuffing box at each end of the valve box, and its central part is
formed into a rectangular frame a, into which is fitted a square
block g, on the back of the slide valve G. The slide valve is thus
driven up and down by the excentric M; but it is also capable of
receiving a lateral motion without affecting its vertical motion. This
lateral motion is given by means of the excentric M, which is

page_text: mounted on the shaft s. This shaft is driven at three times the ve-
locity of the main shaft F, by means of the wheel O, on the main
shaft gearing into the pinion S, of one third of its diameter, on the
shaft s. The excentric N, gives motion by means of the rod 1, to
the lever or bell crank k; j, is another lever or arm of the bell crank,
which communicates the motion to the rod h, which is formed with
a rectangular frame b, b, which is fitted to the block g, and moves
in a different plane to that of the frame a, a. The motions of both
excentrics are thus communicated to the slide valve, the centre of
which moves in the curved path indicated by the red line in Figure
13. The black lines in Figure 13, show the positions of the top and
bottom ports, with the eduction port between them. These ports
are all placed in a diagonal position, and the slide valve is also made
of a diagonal form, and is shown in the section by the blue lines in
Figure 13. The excentrics are so placed, that when the excentric M,
is at the top or bottom of its stroke, the excentric N, is at half-stroke.
The effect of this arrangement is to produce a pause in the action
of the valve, as in the other arrangements herein-before described.
This pause is produced by the joint action of the two excentrics,
causing the valve to move in some parts of its course in a direction
nearly parallel to that of the ports. In lieu of employing the rect-
angular frames a, a, and b, b, the motion may be communicated to
the valve by means of links or connecting rods. This arrangement
may be applied to a cylindrical valve as well as to a flat valve. In
this case the up and down motion may be communicated from the
excentric rod L, to a vertical valve rod placed in the axis of the
cylindrical valve, and attached to it. This valve rod is connected
to the excentric rod L, by a swivel, which allows of its revolving on
its axis. A horizontal arm or lever is fixed to the valve rod, and
connected to the lever j, by a connecting rod.
levers k, j, are placed so that the end of the lever j, may be on the
same level, or nearly so, as the arm or lever on the valve
rod. The cylindrical valve thus receives its up and down motion
from the excentric M, and a reciprocating rotary motion on its axis
from the excentric N. The valve and ports are arranged in a dia-
The bell crank, or

page_text: gonal position, and the action of the valve is similar to that of the
flat valve shewn in Figures 12, and 13.
Figure 14, shews another arrangement of valve and ports adapted
for being driven by two excentrics, in a similar manner to that
shewn in Figure 12. In this case, however, the two excentrics are
to be driven at the same velocity, and placed at right angles or other
suitable angle to each other; or the motions may be taken off in
different directions from the same excentric. The arrangement
shewn in Figure 14, is adapted for being driven by two excentrics
of equal stroke, and acting at right angles to each other. The
centre of the valve will thus move in the circular path shewn by the
red line in Figure 14. The form of the valve G, is shewn in section
by the blue lines in the Figure and the ports are shewn by the black
lines. The eduction port and the adjoining sides of the top and
bottom ports, and the interior of the valve, are made parallel and
at right angles to the sides of the valve, as in an ordinary slide valve,
but the opposite sides of the ports, and the exterior of the valve
are made diagonal, as in the arrangement shewn in Figures 12, and
13. By this construction the opening and closing of the eduction
is regulated by the excentric, which moves the valve in the vertical
direction and is unaffected by the lateral motion communicated from
the other excentric. The admission of the steam, on the contrary, is
effected by both excentrics. The valve shewn in the Drawing is thus
adapted for admitting steam to each end of the cylinder, while the
piston performs about one half of its stroke, and the steam is then
cut off by the closing of the passages and allowed to expand in the
cylinder. The eduction, on the contrary, is kept open during the
whole or nearly the whole of the stroke of the piston. Other degrees
of expansion may be obtained by varying the proportions of the
different parts. When the valve is arranged to move in a circular
path, as in Figure 14, the circular motion may be communicated to
it in any other convenient manner, instead of being derived from
two excentrics, arranged as before mentioned. Thus, in Figure 15,
I have shewn a method of driving the valve by means of toothed

page_text: wheels, and pins or cranks. G, is the valve; W, W, are two toothed
wheels of equal diameter, turning upon pins fixed in the cover of
the valve box, or otherwise suitably supported; w, w, are two pins
fixed in the wheels W, W, and entering holes or sockets in the back
of the valve G. The distance of the centres of these pins from the
centres of their respective wheels is equal to the radius of the red
circle in Figure 14, and the two pins are placed in similar positions
on their respective wheels. X, is an intermediate wheel, gearing into
the wheels W, W, and of the same diameter as those wheels. The
shaft X, of the wheel X, passes through a stuffing box in the cover
of the valve box, and is driven at the same speed as the main shaft
of the engine. The centre of the valve is thus caused to move in
the circular path shewn by the red circle in Figure 14, while the
valve preserves its parallelism. This valve may be constructed of a
cylindrical form like that herein-before described in reference to
Figures 12, and 13. In this case the vertical motion may be given
from one excentric to a valve rod in the axis of the cylinder, while
the lateral motion may be given from another excentric to an arm
fixed on the valve rod in the manner herein-before described in re-
ference to Figures 12, and 13.
Figure 16, shews another arrangement of valve gear, in
which the valve G, receives an up and down motion from the
excentric M, and a reciprocating rotary motion from the ex-
centric N. The excentric M, is fixed upon the main shaft F,
and is connected by the excentric rod L, to the valve rod H;
the valve rod H, is guided by a stuffing box at each end of the
valve box, and is provided with a socket in its centre, which is fitted
on a round pin g, on the back of the valve G. The valve is thus
capable of turning on the pin while being moved up and down by
the rod H. O, is a toothed wheel fixed on the main shaft F, and
driving a pinion S, of one third of its diameter, on the shaft S, which
carries the excentric N, which thus makes three revolutions while
the excentric M, and the main shaft make one revolution. The
excentric N, communicates motion by means of the rod 7, bell crank

page_text: or levers k, j, rod h, and link b, to a pin c, on the back of the valve
G. The excentrics are so arranged, that when the excentric M,
is at the top or bottom of its stroke, the excentric N, is at half stroke,
and the pin c, is thus caused to move in the curved path shewn by
the red line in Figure 17. The blue lines in Figure 17, shew a
section of the valve G, the ends of which are curved both on the
exterior and interior; Figure 18, shows the eduction passage or
port, and the ports leading to the top and bottom of the cylinder,
which are curved like the valve. The effect of this arrangement is,
that the action of the up and down motion of the valve, in opening
and closing the ports, is counteracted in some parts of the stroke,
and increased in other parts of the stroke, by the rotary motion im-
parted to the valve from the excentric N. When these motions
counteract each other, a pause in the action of the valve is produced
as in all the other arrangements of valve gear herein-before described,
and the steam is thus made to act expansively. This arrangement
may be varied, by altering the proportions of the various parts and
the form of the valve. The various arrangements of valve gear
herein-before mentioned have been described generally as applied to
an engine of a form similar to that shewn in Figures 1, 2, and 3; but
it is obvious that they may be applied to steam engines of other forms
and constructions. Also, in lieu of employing two cranks or two
excentrics, one crank and one excentric may be employed in many
of the arrangements herein-before described, and the length or throw
of the cranks or excentrics may be made adjustable for the purpose
of varying the action of the valves.
Figure 19, is a vertical section explanatory of my improve-
ments in heating the cylinders of steam engines; A, is the
cylinder, surrounded by a jacket or casing d; e, is a close cylin-
drical vessel or boiler placed over a fire grate n, and connected
to the jacket d, by the two pipes o, p. The pipe o, rises from the
top of the boiler c, and enters the top of the jacket d, while the
pipe p, connects the bottom of the jacket d, with the bottom of
the boiler e; r, is an open cistern, connected to the top of the

page_text: jacket d, by the pipe t. The jacket d, boiler e, and pipes o, p, t,
are filled with oil, which is introduced at the cistern r, until the
bottom of the cistern is covered by it. A fire is made on the
grate n, and the heated oil ascends through the pipe o, enters
the jacket d, and, after communicating a portion of its heat to the
cylinder, descends through the pipe p, to be again heated in the
vessel e.
A constant circulation of hot oil is thus maintained, and
the cylinder may thus be heated to a temperature considerably above
that of boiling water. At the same time the open cistern r, allows
free space for the expansion of the oil by the heat, and also allows
of the escape of any vapour which may be generated, so that no part
of the apparatus is exposed to any greater pressure than that due
to the column of oil. This would not be the case if water were
employed in lieu of oil, to heat the cylinder, as it would be neces-
sary to close the cistern r, and to employ a considerable pressure
to enable the water to acquire a sufficiently high temperature to be
employed with advantage for heating the cylinder. The cistern r,
may be covered with a loosely fitting cover to exclude dust and
dirt, or it may have a close top with a small aperture for the in-
troduction of the oil and the escape of gas or vapour.
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
I do not here claim generally the application of two excentrics or
cranks to the working of a slide valve, so as to produce a pause in
its action, but what I claim, is, -
Firstly, the constructing of valve gear as herein-before described,
in reference to Figures 1, 2, 3, 4, 5, 6, 7, 8, and 9.
Secondly, the constructing of valve gear, with the arrange-
ments for varying the expansion by altering the position of one or
more of the toothed wheels, as herein-before described in reference
to Figures 1, 2, 3, 10, and 11.
Thirdly, the constructing of valves and valve gear in such manner
that the valves receive both longitudinal and lateral motion, as
herein-before described in reference to Figures 12, 13, 14, 15,
117

page_text: Fourthly, the mode of heating the cylinders of steam engines, by
means of heated oil, as herein-before described.
In witness whereof, I, the said Frederick Joseph Bramwell, have
hereunto set my hand and seal, this Sixteenth day of June, in
the year of Our Lord One thousand eight hundred and fifty-
three.
Witness,
FREDERICK JOSEPH BRAMWELL. (L.S.)
GEORGE H. BOVILL,
19, Abchurch Lane,
London.