IMPROVE. .MENTS IN STEAM AND OTHER MOTIVE-POWER ENGINES
Year: 1868

page_text: LETTERS PATENT to James Howden, of Glasgow, in the County of
Lanark, North Britain, Engineer, for the Invention of " IMPROVE.
.MENTS IN STEAM AND OTHER MOTIVE-POWER ENGINES."
Sealed the 11th December 1868, and dated the 13th June 1868.
PROVISIONAL SPECIFICATION left by the said James Howden at the
Office of the Commissioners of Patents, with his Petition, on the
13th June 1868.
I; JAMES HOWDEN, of Glasgow, in the County of Lanark, North
Britain, Engineer, do hereby declare the nature of the said Invention
of "IMPROVEMENTS IN STEAM OR OTHER MOTIVE-POWER ENGINES," to be as
follows, that is to say:
My improvements consist chiefly. in new methods and arrangements
for working the valves in steam or other motive-power engines, by which
the power usually expended in giving motion to the valves is greatly.
reduced, and the action of the steam, air, gas, water, or other fluid in
the cylinder rendered more effective. These improved arrangements are
also combined in some cases with a regulating movement in connection

page_text: with the governor, by which a uniform speed is maintained by varying
the admission of the steam, air, gas, water, or other fluid in proportion to
the amount of work to be done.
In one modification of the improvements under this Invention (which
for convenience is here described as applied to a horizontal steain
engine), a shaft is placed parallel to the axial line of the cylinder, and
on the same horizontal plane. This shaft, which is carried in suitable
bearings, and driven by bevil or other gear from the crank shaft is placed
at a convenient distance from the cylinder and extends lengthways as
far as its outer end. The cylinder has two inlet valves on its upper side,
one at each end, and two outlet or exhaust valves on its under side, also
placed at each end, and the four valves are worked by cams from the
horizontal shaft previously described, the motion of the valves being
across or at right angles to the axial line of the cylinder.
The ports
are of the grating or gridiron kind, the several openings being short
lengthways; the valves are also of the gridiron kind to suit the ports,
and require a very small amount of travel to open or shut them fully.
The exhaust valves bear against their respective cylinder faces on their
upper side, and also against faces on the engine seat or stool on their
under side, and the steam passes from the cylinder through the valves.
The cams for working the inlet and outlet valves for the inner end of
the cylinder are placed closely together on the shaft opposite the valves,
and the cams for working the inlet and outlet valves at the outer end of
the cylinder are similarly placed opposite their valves at the outer end
of the cam shaft. The cams work the valves in this modification
through levers which are in connection with the valve spindles at one
end and the cams at the other, there being one cam and one lever for
each valve. The cams are circular on their outside edge, the projections
for opening and shutting being fixed in each within a broad and deep
parallel groove on their sides. The cams for working the outlet or
exhaust valves are fixed on the cam shaft and have their projecting
pieces for opening and shutting their respective valves so arranged that
the valves are nearly fully open before the piston begins the return
stroke, and remain standing open until the stroke is nearly terminated.
When the inlet valves are made to admit more or less steam while the
engine is at work by means of adjustable gear worked by the action of
the governor, the cams for opening and shutting these valves are, each
made in two pieces, the parts having the projections for opening the

page_text: valves being fixed on the cam shaft so as always to open their respective
valves at the same place. The parts for shutting the valves are made
capable of being moved round within a certain limit on the shaft, so
that they may cut off the steam earlier or later in the stroke according as
they are moved forward or backwards on the shaft. These cut-off"
parts of the two inlet cams are not fixed directly on the cam shaft, but
on a tube or hollow shaft carried by the cam shaft proper. This tube
extends from the fixed cams at one end to those at the other end of the
cylinder, and is kept from moving endways on the shaft by these cams.
It carries a collar or sliding sleeve capable of being moved endways on
it by the action of the governor. A cottar passes through this collar
from side to side, and at the same time diametrically through the tube
and cam shaft, so that when the latter revolves the tube and collar are
turned round with it by means of the cottar. The cottar being fixed in
the sliding collar both the cam shaft and tube are slotted to allow of
the motion of the cottar endways. The slot in the cam shaft is straight,
while that in the tube is cut somewhat angularly to its axis, so that
when the collar is moved along in one direction the tube having on it
the "cut-off" parts of the inlet cams is set forward on the shaft
relatively with the other cams, and an earlier "cut-off" effected, while
by moving the collar in the contrary direction the cams and tube are
set backwards on the shaft, and give a later "cut-off." The movement
of the collar along the tube is effected by means of a screw motion
derived from the sleeve of the governor. This sleeve which is raised
and lowered on the spindle by the arms of the governor in the usual
manner has two circular flanges, an upper and lower, between which is
placed a friction or toothed wheel on a spindle at right angles to the
governor spindle. When the engine is working at its proper speed
neither flange is in contact with the friction wheel, but whenever the
speed is slightly increased the lower flange is brought into contact with
it and gives motion endways through a screw and suitable connections
to the collar on the hollow shaft so as to "cut-off "earlier. This motion
is continued until the engine is brought to its proper speed, when the
balls of the governor resume their normal position and leave the cams
admitting the necessary quantity of steam. When the engine falls
slightly below the proper speed the same action takes place but in the
contrary direction. The governor may also be connected directly to this
sliding collar, and any kind of regulator may be used, whether depend-
ing on the action of centrifugal force and that of gravity or not.
The

page_text: "cut-off" may also be adjusted through the sliding collar by hand gear
when a governor is not used. When the valve gear now described is
applied to a pair of engines no additional cam shaft, cams, or governor
are required. This shaft then passes between the two cylinders, and the
cams work their respective valves on both cylinders. It is
necessary only that the ends of the valve levers of each cylinder with
their friction rollers come in contact with the cams at an angular
distance from each other equal to the angular distance of their respective
cranks from each other.
same
Another modification of the improved arrangements of valves and
methods of working the same comprehended under this Invention,
consists in having the projecting pieces of the cams arranged on the
sides of the discs so as to give motion to their respective levers in a
parallel direction to the axis of the shaft, instead of at right angles to
it as in the arrangement herein-before described. When the cams are
thus constructed the levers may either work valves similar to those
already described, or they may be connected directly to their valve
spindles. so as to turn the spindles radially. In the latter case the
valves may be of the cylindrical kind and turn with the spindle on the
same axis, or they may have flat working faces with their motion in
the line of the axis of the cylinder, and worked either from the radial
motion of the valve spindle inside the valve box, or from the outside in
the usual manner. When the valves are cylindrical, or when they move
in the line of the axis of the cylinder, the ports lie lengthways across
the cylinder. It is also preferred to make them very narrow and not less
than two in number for each valve, so as to require a very short motion
of valve to open and shut them.
Another modification comprehended under this Invention consists in
placing the valve cams on the crank shaft and working the valves
previously described by means of rods and levers connecting the cams
at one end with the valves at the other end. The motion may be taken
directly from the cam levers on the shaft to the levers on the valve
spindles, either by rods or spindles having a motion on their own axis,
or by rods having a longitudinal motion only. In some cases it may be
found necessary to have the cams on an intermediate shaft driven by
suitable gear from the crank shaft, and the cam shafts may also be
arranged so that the cams may work the valves direct without the
intervention of levers. The exhaust valves may also be arranged to

page_text: be worked by one cam, the same motion closing one while opening the
other.
The arrangements of valves and methods of actuating them as herein
before described are also applicable to engines having their cylinders
placed vertically or at any other angle to the horizon. They can also be
arranged to reverse the motion of the engine when required. In those
engines requiring a reversing motion the cams may be driven by catches
on the shaft and left free to move radially on the shaft within a certain
limit, the valves being worked by hand until a reverse motion is
obtained. The projections are arranged on the cams to give the opening
and shutting movements at the proper time in relation to the crank.
When the cams are not on the crank shaft they may be put into the
proper position for the reverse motion by means of a clutch or driver on
the cam shaft. They may also be changed to the required position by
means of the movement herein-before described in connection with the
governor and variable "cut off" by any of the methods in use for this
purpose. The cams may also be made to revolve always in one
direction though the engine may be reversed in its motion by having
two driving wheels for the cam shaft. When the engine is turning in
one direction one of the wheels drives the cam shaft, the other being
out of gear.
When the engine is reversed the one formerly in gear is
thrown out and the other wheel thrown into gear, the clutch for effecting
this having its catches arranged so as to bring the cams always into
their proper position in relation to the crank.
When the improved arrangements herein-before described are applied
to the cylinders of oscillating engines, the levers for working the valves
have their axial spindles attached to the cylinders and move to and fro
with them. One arm of these levers is in connection with its respective
valve or valve spindle, and the other arm is in connection with a curved
slot link or segment having a short movement either parallel to the
axial plane of the cylinder or at right angles thereto, according as the
valves are moved in the line of or across the cylinder. It is preferred
to work the valves across the cylinder, and the curved slot segments in
the corresponding manner. The curved segments receive their motion
from levers worked by the cams as herein-before described. .
Another improvement in the application of these valves to oscillating
engines consists in working the valves partly by means of the motion of
the cylinder itself and partly by an independent motion. In this

page_text: arrangement it is also preferred to have the valves of the gridiron
kind working across the cylinder.
In this modification the roller or pin in the end of each inlet valve
lever in being moved in the curved slot segment by the oscillation of
the cylinder comes in contact with a moveable striking piece, which
gives motion to the lever and opens the valve at the proper time. The
valve remains open until the continued motion of the lever brings it
into contact with another striking piece on the opposite side of the slot
which shuts the valve. This latter piece is adjustable by hand gear, so
as to cut off" at different parts of the stroke, and requires no other
motion. Before the oscillation of the cylinder brings back the lever on
its return motion the striking piece in the slot that opened the valve
is withdrawn by gear worked from the engine shaft so as to allow the
lever to pass without being moved. After the lever pin or roller has
passed that part of the slot the striking piece is again put into position
to move the lever on its return and open the valve as before. The inlet
or cut-off valves are in this arrangement always shut before the piston
has reached one half of its stroke. The exhaust valves are also opened
by moveable striking pieces in the manner just described. They are
also shut by a moveable striking piece worked in connection with the
opening piece. As the one is withdrawn from the line of the lever's
motion the other is brought into it so as shut the valves just before
the piston has terminated its stroke. When the engines are turning in
one direction the striking pieces are all on one side of the curved
segments in which the lever pins work. When the engines are reversed
the striking pieces are withdrawn by suitable gear from those halves of
the curved segments, and another set brought into motion on the other
halves of the segments. The shutting or cut off pieces in the segments
for the inlet valves are not altered when reversing, one piece always
remaining ready in position at each end.
"
Another improvement comprehended under this Invention relates to
the working of "cut-off" valves entirely by the motion of the cylinder
in connection with the ordinary slide valves in oscillating engines.
These cut-off" valves are preferred to be of the gridiron kind and
arranged on the side of the main valve chests with their working faces
at about right angles to the main slide valve faces, and their motion
in the same direction. The lever for working the cut-off valve has one
end in connection with its valve or valve spindle, and its other end in

page_text: connection with a fixed curved slot segment. This curved segment has
a fixed striking piece against which the end of the lever strikes in the
course of its motion, and opens the valve and admits steam to the main
valve chest. This striking face is placed so as to open the valve after
the shutting and before the opening of the steam ports by the main
slide valve. The onward motion of the cylinder brings the lever against
a projecting piece on the opposite side of the slot in the curved segment,
which shuts or cuts off the steam before the piston has completed half
its stroke. The cylinder on its return movement brings the end of the
lever against the other side of the opening striking piece, and again
opens the valve before the termination of the stroke of the piston. The
onward motion of the cylinder on the other side brings the lever into
contact with a second projecting piece on the opposite side of the
slot at the other end of it, which shuts the valve as before. These two
shutting pieces are adjustable by hand, so as to cut off at any point
within a certain range below the half stroke. This cut-off arrangement
requires no other gear except for working the valve by hand.
Another portion of the improvements comprehended in this Invention
relates to the arranging and working of the valves in those engines
where the steam after having acted on the piston of one cylinder passes
into and actuates the piston of a second cylinder.
In one of these improved arrangements the exhaust valves on the
second cylinder are separate from the valves admitting the steam from
the one cylinder to the other. These latter are placed one at each end
between the two cylinders, and bear against each cylinder face, and the
steam passes right across through the valve from the outer end of one
cylinder to the outer end of the other cylinder, and in the same manner
at the inner end without having to fill any steam chest or space. This
arrangement of valves may also be used without passing the steam
through the valves between the cylinders or having them bearing on
both faces. The steam may 'then pass over the end of the valves when
they have their motion in a line with the axes of the cylinders, and the
valves work only on the face of the low-pressure cylinder. In these
arrangements it is preferred to have the exhaust valves placed at right
angles to those between the two cylinders. The valves may either be
of the gridiron kind previously described with their motion at right
angles to the axes of the cylinders, or they may have their ports
lengthways across the cylinders and their motion in the line of the

page_text: axes of the cylinders. The valves may be worked by cams as herein-
before described, or by eccentrics in the usual manner, and the valves
admitting the steam from one cylinder to the other and the exhaust
valves may be worked from the same movement or by distinct movements.
When the valves between the two cylinders have their motion in
the direction of the axes of the cylinders, and the exhaust valves at
right angles thereto, the latter valves may then be worked from the
valve spindle of the former by means of a lever or levers having a scroll-
shaped groove or slot in one end, in which a pin or friction roller
attached to the aforesaid valve spindle works and gives the required
motion. The groove in the end of the lever or levers is made of such a
conformation that the pin.or roller moving up or down in a straight line,
works the end of the lever or levers to and fro as required for the
opening and shutting of the exhaust ports. When one lever is used it
is connected at its axis to a spindle reaching to both ends of the
cylinder, and through it works both outer and inner exhaust valves, the
one closing and the other opening by the same motion. When two
levers are used the valves are worked independently.
A modification of the improved arrangement of valves previously
described, consists in passing the steam from the high to the low pressure
cylinder through the valves," when the exhaust from the low-pressure
cylinder is also effected by the same valves. In this case the valves
bear on both cylinder faces, and the steam passes through them. from
one cylinder to the other in a straight line or nearly so, without filling
any steam chest or space further than the passages through the
valves and the ports of the low-pressure cylinder. In these arrange-
ments now described the steam is admitted to the first cylinder by a
separate valve or valves worked by an independent motion, and they
may not necessarily be of the improved kind herein-before described.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of June, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors
give and grant unto me, the said James Howden, Her special licence
that I, the said James Howden, my executors, administrators, and
assigns, or such others as I, the said James Howden, 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 "IMPROVE-
MENTS IN STEAM AND OTHER MOTIVE-POWER ENGINES," upon the condition
(amongst others) that I, the said James Howden, 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 James Howden, do hereby declare
the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by
the following statement; that is to say:―
My improvements consist chiefly in new methods and arrangements
for working the valves of steam or other motive-power engines by which
the power usually expended in giving motion to the valves is greatly
reduced and the action of the steam, air, gas, water, or other fluid in the
cylinder rendered more effective. These improved arrangements are
also combined in some cases with a regulating movement in connection
with the governors, by which a uniform speed is maintained by varying
the admission of the steam, air, gas, water, or other fluid in proportion to
the amount of work to be done.
In one modification of the improvements under this Invention, which
for convenience is here described as applied to a horizontal steam engine
and represented in Figures 1, 2, and 3, Sheet. 1, of the accompanying
Drawings, a shaft. A is placed parallel to the axial line of the cylinder B,

page_text: and on the same horizontal plane. This shaft is carried in suitable
bearings and driven by bevil gear from the crank shaft C. The cylinder B
has two inlet valves D, D, on its upper side, one at each end, and two
outlet or exhaust valves E, E, on its under side, also placed at each end.
The four valves are worked by cams from the horizontal shaft previously
described, the motion of the valves being across or at right angles to the
axial line of the cylinder. The parts in the cylinder, both inlet and
outlet, are of the grating or gridiron kind, the several openings being
short lengthways. The valves have similar openings to suit the ports
and require a very short travel to open or shut them fully. The exhaust
valves bear against their respective cylinder faces on their upper side,
and also against the faces on the engine seat or stool on their under
sides, and the steam passes from the cylinder through the valves. The
exhaust valves may in some cases be made so as to bear only on their
under faces. The cams for working the inlet and outlet valves for the
inner end of the cylinder are placed closely together on the shaft opposite
their respective valves, and the cams for working the inlet and outlet
valves at the outer end of the cylinder are similarly placed opposite their
valves at the outer end of the cam shaft. The cams work the valves in
this modification through levers which are in connection with the valve.
spindles at one end and the cams at the other end, there being one cam
and one lever for each valve. The cams are circular on their outside
edges, the projections for opening and shutting being fixed in each
within a broad and deep parallel groove on their sides. The cams F, F,
for working the outlet or exhaust valves, are fixed on the cam
shaft, and have their projecting pieces for opening and shutting the
respective valves so arranged that the valves are nearly fully open before
the piston begins the return stroke, and remain standing open until the
stroke is nearly terminated. In cases, however, where compression or
cushioning is required the cams can be made to close the exhaust ports
at any part of the stroke without altering the point of opening. When
the inlet valves D, D, are made to admit more or less steam while the
engine is at work by means of adjustable gear worked by the action of
the governor, the cams for opening and shutting these valves are each
made in two pieces, the parts G, G, carrying the projections for opening
the valves being fixed on the cam shaft A, so as to always open their
respective valves at the same place in relation to the position of the
piston. The parts H, H, for shutting the valves are capable of being
moved round within a certain limit on the shaft A, so that they may
cut

page_text: off "the steam earlier or later in the stroke according as they are moved
forward or backwards on the shaft. These cut-off" parts of the two
inlet cams are not fixed directly on the cam shaft, but on a tube or
hollow shaft I carried by the cam shaft proper. This tube extends from
the fixed cams at one end of the cylinder to those at the other end, and
It carries a
is kept from moving endways on the shaft by these cams.
collar or sliding sleeve J capable of being moved endways on it by the
action of the governor.
A cottar passes through this collar from side to
side and at at the same time diametrically through the tube I and cam shaft
A, so that when the latter revolves the tube and collar are turned round
with it by means of the cottar. This cottar being fixed in the sliding
collar both the cam shaft and the tube are slotted to allow of the motion
of the cottar endways. The slot in the cam shaft is straight or in a line
with the axis, while that in the tube is cut angularly to the axis, so that
when the collar is moved along in one direction the tube carrying the
"cut-off" parts of the inlet cams is set forward on the shaft relatively
with the other cams and effects an earlier "cut off," while by moving
the collar endways in the contrary direction the tube and cams are set
backwards on the shaft and give a later "cut off." The movement of
the collar along the shaft is effected in this instance by means of a screw
motion derived from the sleeve of the governor K. This sleeve, which
is raised and lowered by the arms of the governor in the usual manner,
has two circular flanges, and upper and a lower, between which is placed
a friction wheel on a spindle at right angles to the governor spindle.
When the engine is working at its proper speed neither flange is in
contact with the friction wheel, but whenever the speed is slightly
increased the lower flange is brought into contact with it and gives
motion endways through suitable gear to the collar J, so as to give an
earlier cut off " by the cams.
This motion is continued until the
engine is brought to its proper speed, when balls of the governor
resume their normal plane of revolution, relieving the friction wheel and
leaving the cams admitting the necessary quantity of steam. When the
engine falls slightly below the proper speed the same action takes place,
but in the contrary direction, by the upper flange on the governor's
sleeve coming in contact with the friction wheel. The friction faces are
shewn rectangular, but they may have bevilled faces. In the arrange-
ment shewn in the accompanying Drawings the motion from the
governor is conveyed to the sliding collar J on the cam shaft by a belt
from a pulley on the spindle of the friction wheel to a pulley on the
1

page_text: spindle L under the cam shaft. This spindle L has a forked arm at one
end in connection with the sliding collar J, and is screwed at the other
end, the belt pulley being made to serve also as the nut for the screw,
and which according to the direction in which it is turned screws the
spindle along in either direction.
The governor may also be directly
connected to the sliding collar J, or it may be connected by a different
arrangement of gear, and any suitable kind of governor may be used to
give motion to the sliding collar. The "
cut off "
may also be adjusted
through the sliding collar by hand gear when a governor is not used, or
is not in connection with the cam shaft
gear.
When the valve gear now described is applied to a pair of engines
no additional cam shaft, cams, or governor are required. The shaft
then passes between the two cylinders, which are placed at a convenient
distance on either side of the shaft, and the same cams work their
respective valves on both cylinders. It is necessary only that the ends
of the valve levers of each cylinder with their respective friction rollers
come in contact with the cams at an angular distance from each other
equal to the angular distance of their respective cranks from each
other.
The foregoing references have been made in connection with Figures 1,
2, and 3, Sheet 1, of the accompanying Drawings, Figure 1 being a
sectional elevation; Figure 2, a cross section through the cylinder on
the line A', B'; and Figure 3, a plan.
Figures 4, 5, 6, and 7 on same Sheet shew the cams and their
arrangement in detail, Figure 4 shewing all the cams on the cam shaft
and hollow tube; Figure 5 shews the face of one of the exhaust cams E
with the opening and shutting projections; Figure 6 shews the face of
the opening part G of one of the inlet cams; and Figure 7 the face of
one of the shutting parts H of the same cams. In all these cams the
opening projections are on the inner circles of the grooves, and the
shutting projections on the outer circles, but the positions of these
projections may be reversed, and the shape of the projections also made
differently so as to give a quicker or slower opening or shutting
motion.
Another modification of the improved arrangements of valves and
methods of working the same comprehended under this Invention
consists in having the projecting pieces of the cams arranged on the
sides of the discs so as to give motion to their respective levers in a

page_text: parallel direction to the axis of the shaft, instead of at right angles to
it, as in the arrangement herein-before described. When the cams are
thus constructed the levers may be made either to work valves similar
to those already described, or they may be connected directly or by
an intervening lever to their valve spindles so as to turn them radially.
In the latter case the valves may be of the cylindrical kind, and turn
with the spindle on the same axis, or they may have flat working faces
with their motion in the line of the axis of the cylinder, and be worked
either from the radial motion of the valve spindle inside the valve box,
or from the outside in the ordinary manner. When the valves are
cylindrical or when they move in the line of the axis of the cylinder
the ports lie lengthways across the cylinder. It is preferred to make the
ports very narrow, and not less than two in number for each valve
though one may also be used, so as to require a very short travel of
valve to open or shut them.
In Sheet 1 of the accompanying Drawings Figures 8 and 9 shew a
modification where cylindrical valves are worked from cams with side
projections, the levers on the valve spindles receiving their motion from
the cams through intermediate levers M, M, to lessen the amount of the
projections on the cam faces. In some cases the cams may be placed
on separate shafts, one for the inlet valves above, and one for the outlet
valves below, both shafts being driven from the crank shaft by suitable
gear. It is not necessary that these outlet cylindrical valves bear
against the cylinder faces on their upper sides.
All the arrangements of valves previously described may also be
worked by having only one cam for the inlet valves, and one for the
outlet valves. In such cases all that is necessary is to have the two
levers for the inlet valves placed in contact with the cam so as to be
diametrically opposite to each other, and the two levers for the outlet
valves in same position with regard to their cam. The spindles on
which these levers turn are extended so as to allow of the motion
from the cams to be conveyed to each valve by a single-ended lever or
by a rod and lever.
Another modification comprehended in this Invention consists in
placing the valve cams on the crank shaft and working the valves pre-
viously described by means of rods and levers connecting the cams at one
end with the valves at the other end. The motion in such cases may be
conveyed directly from the cam levers at the shaft to the levers on the

page_text: valve spindles either by rods or spindles having a motion round their
own axes, or by rods having a longitudinal motion only.
Figure 10, Sheet 1 of the Drawings, shews an arrangement where
valves having their motion in the line of, the axis of the cylinder are
worked direct from single cams on the crank shaft by rods with a
longitudinal motion. The levers N, N, receive their motion from one
cam, and work the two inlet valves by the rods O, O; the two outlet
valves are also worked from one cam in similar manner.
Figures 11 and 12 on same Sheet shew valves having their motion
across the cylinder worked direct by cams on the crank shaft through
spindles having their motion round their axes.
In some cases it may be found necessary to have the cams for the
arrangements just described on an intermediate shaft driven by suitable
gear from the crank shaft, and the cam shafts may also be arranged
so that the cams may work the valves without the intervention of
levers. The exhaust valves may also be arranged to be worked by
one cam where the same motion while it opens one valve closes the
other.
The arrangement of valves and the methods of actuating them, as
herein-before described, are also applicable to engines having their
cylinders placed vertically or at any other angle to the horizon. They
can also be arranged to reverse the motion of the engine when required.
In those engines requiring a reversing motion the cams may be driven
by catches on the shaft, and left free to move radially on the shaft
within a certain limit, the valves being worked by hand until the reverse
motion is obtained. The projections on the cams are arranged to give
the opening and shutting movements at the proper time in relation to
the motion of the crank. When the cams are not on the crank shaft
they may be put into the proper position for the reverse motion by
means of a clutch or driver on the cam shaft. They may also be changed
to the required position by the movement previously described in con-
nection with the governor and variable " cut off or by any other
suitable methods. The cams may also be made to revolve always in
one direction though the crank shaft may be reversed in its motion by
having two driving wheels for the cam shaft. When the engine is
turning in one direction one of these wheels is driving the cam shaft,
the other being loose on the shaft and out of gear. When the engine
is to be reversed the one formerly in gear is thrown out and the other

page_text: wheel into gear, the clutch for effecting this having its catches arranged
so as to bring the cams always into their proper position in relation
to the cranks. Small starting valves or cocks on the cylinders to be
worked by hand in connection with these reversing arrangements
facilitate the operation; and also for this purpose provision may be
made to shut or open any of the inlet or outlet valves by hand at
starting when required.
Figures 13, 14, and 15, Sheet 2, which are respectively a front
elevation, side elevation, and plan, shew an arrangement with the
valves applied to a pair of inverted cylinder engines where the cam
shaft always revolves in the same direction, the engines going either
way. In this arrangement also one cam works the inlet and one the
outlet valves of both cylinders at each end. The wheels P, P, are both
always in contact with the wheel on the cam shaft, but only the one
with which the clutch R is engaged is in connection therewith.
When the improved arrangements herein-before described are applied
to the cylinders of oscillating engines the levers for working the valves
have their axial spindles attached to the cylinders and move to and fro
with them. One arm of these levers is in connection with its respec-
tive valve or valve spindle, and the other arm is in connection with a
curved slot link or segment having a short movement either parallel
to the axial plane of the cylinder or at right angles thereto, according
as the valves are moved in the line of or across the cylinder. It is
preferred to work the valves across the cylinder, and the curved slot
segments in the corresponding manner.
Figures 16 and 17, Sheet 2 of the Drawings, respectively an elevation
and plan, shew this arrangement. S, S, are the inlet valves at each
end of the cylinder; T, T, are the outlet valves similarly placed on the
opposite side of the cylinder. The slot segments U, U, U, U, of which
there are four for each cylinder, work horizontally in parallel guides
attached to the columns. The cam shaft V actuates each slot segment
on one side or for one engine direct by a cam, while the same cam
actuates the corresponding slot segment for the other engine (when a
pair work together) through an intervening lever, as shewn in plan in
Figure 17. The inlet and outlet valves at the upper end of the
cylinders are worked direct from the two upper slot segments through
the double-ended levers W, X, and the inlet and outlet valves at the
lower end of the cylinders are worked by the two lower slot segments

page_text: through single-ended levers in connection with them at the upper ends
of the spindles Y, Z, and similar levers on the spindles at their lower end
in connection with the valves S, T.
Another, improvement in the application of these valves to oscillating
engines consists in working the valves partly by means of the motion
of the cylinder itself and partly by an independent motion. In this
modification the friction roller or pin in the end of each inlet valve lever
in being moved in the curved slot segment by the oscillation of the
cylinder comes in contact with a moveable striking piece which gives
motion to the lever, and opens the valve at the proper time. The
valve remains open until the continued motion of the lever brings it
into contact with another striking piece on the opposite side of the slot
which shuts the valve. This latter piece is adjustable by hand gear,
so as to give the "cut off" sooner or later, as may be desired, and
requires no other motion. Before the oscillation of the cylinder brings
back the lever on its return motion the striking piece in the slot that
opened the valve is withdrawn by gear worked from the engine shaft
so as to allow the lever to pass without being moved. After the lever
pin has passed that part of the slot the striking piece is again put
into position to move the lever and open the valve as before, when the
lever again arrives at the same position. The inlet or "cut-off valves
in this arrangement are always shut before the piston has reached one-
half of its stroke; the outlet or exhaust valves are also opened by
moveable striking pieces worked in the manner just described. They
are also shut by a moveable striking piece worked in connection with
the opening piece, and placed near the middle of the slot; as the
opening piece is withdrawn from the line of the lever's motion the
other is brought into it so as to shut the valve just before the piston
has terminated its stroke. When the engines are reversed the opening
pieces for the inlet valves require a very slight adjustment so as to give
the same lead to the valves when backing; this can be done by the
cams giving the motion to the pieces or by any suitably arranged gear.
The shutting or cut-off pieces for the inlet valves are not altered
when reversing, one piece always remaining ready in position at each
end.
<6
"
Figure 18, Sheet 2 of the Drawings, is a plan of an oscillating engine
shewing in part this latter arrangement.
a is one of the slot segments
piece b worked by the smal!
for the inlet valves with the opening

page_text: cam C on the cam shaft d, and e, e, are the shutting pieces; the
segments for working the exhaust or outlet valves are not shewn. The
cam shaft which may be made very light is worked from the main
shaft as herein-before described.
"
Another improvement comprehended under this Invention relates to
the working of cut-off valves entirely by the motion of the cylinder
in connection with the ordinary slide valves in oscillating engines.
These cut-off valves are preferred to be of the gridiron kind and
arranged on the sides of the main valve chests with their working
faces at about right angles to the main slide valve faces, and their
motion in the same direction. They may be also arranged on the
back of the slide valves either directly or with an intervening plate.
The lever piece for working the "cut-off valve has one moveable
end in connection with the valve or valve spindle, and its other moveable
end in connection with a fixed curved slot segment. This curved
segment has a fixed striking piece on one side of the slot and about
the middle of it, against which the pin or roller in the end of the
lever comes in contact in the course of its motion and opens the valve,
and admits steam to the valve chest after the main slide valve has
shut the steam port at one end and just before it opens the port at
the other end. The onward motion of the cylinder brings the end
of the lever against a projecting piece on the opposite side of the slot
in the curved segment, which shuts the valve and cuts off the steam
before the piston has completed half its stroke. The cylinder on its
return movement brings the end of the lever against the other side
of the opening piece in the segment, and opens the valve before the
termination of the stroke of the piston. The continued motion of the
cylinder brings the lever into contact with a second projecting piece
on the opposite side of the slot at the other end, which shuts the
valve as before. The two shutting pieces are adjustable by hand so
as to "cut-off" the steam at any point within the half stroke of
the piston. This "cut-off" arrangement which requires no other gear
or motion for working it is shewn in Figures 19 and 20, Sheet 3, of
the accompanying Drawings. f. f, are the curved slot segments; g, g,
are the "cut-off valve lever pieces working on their fixed centres h, h,
and carrying the rollers working in the segments, their other ends
being attached to their respective valve spindles i, i; k, k, are the
openings pieces; and 1, 1, 1, 1, are the several shutting pieces at the

page_text: extremities of the slots. One of the 66 cut-off valves m is shewn in
Figure 20 with its face at nearly right angles to the main slide valve,
'while the other n is shewn working on a plate against which the
back of its slide valve works. Both arrangements allow the main slide
valves to have packing rings for relieving the pressure on their backs.
Another improvement comprehended in this Invention relates to the
arranging and working of the valves in those engines where the steam
after having acted on the piston of one cylinder passes into and actuates
the piston of a second cylinder. In one of the improved arrange-
ments the exhaust valves on the second cylinder are separate from
the valves which pass the steam. from one cylinder to the other. These
latter valves are placed one at each end between the two cylinders and
bear against each cylinder face. The steam passes right through a
passage in the valve from the outer end of one cylinder to the outer
end of the other cylinder, and in the same manner at the inner end
without having to fill any steam chest or space. In some cases the
valves between the cylinders may be made to bear on the low-pressure
cylinder face only and the steam may pass over the end instead of
through the valves. The valves may all be of the gridiron kind
previously described, with their motion at right angles to the axes of
the cylinders, or they may have one or two ports only. and their motion
in the line of the axes of the cylinders. The valves may be worked
by cams as herein-before described, or by eccentrics in the usual manner,
and the valves that pass the steam from one cylinder to the other
and the exhaust valves may be worked either by the same or by distinct
movements. When the valves between the two cylinders are worked
by eccentrics and have their motion in the line of the axes of the
cylinders, and the exhaust valves have their motion at right angles
thereto, the latter valves may then be worked from the valve spindle
of the former by means of a lever or levers having a scroll-shaped
groove or slot at one end, in which a pin or friction roller attached
to the aforesaid valve spindle works and gives the required motion
to the lever. The groove or slot in the end. of the lever or levers is
made of such a conformation that the pin or roller moving up and
down in a straight line with the spindle works the end of the lever
or levers to and fro as required for the opening and shutting of the
exhaust ports. When one lever only is used it is connected at its
axis to a spindle reaching to both ends of the cylinder and through

page_text: it works both the outer and inner exhaust valves, the one valve opening
and the other closing by the same motion. When two levers are used
there are two pins on the valve spindle and each exhaust valve is
worked independently of the other. Instead of the grooves being in
the end of the levers and the pins on the valve spindle, the grooves
may be carried by the valve spindle, and the pins or rollers be on
the ends of the levers, the motion produced being equally the same.
This motion only takes place when opening or shutting, the shape of
the grooves being such as to leave the valves remaining standing
either open or shut during the greater portion of the stroke.
A modification of the improved arrangement of valves for engines
working the steam from one cylinder to another consists in passing the
steam from the high to the low pressure cylinder through the valves
when the exhaust from the low-pressure cylinder is also effected by the
same valves. In this case the valves are placed between and at each
end of the cylinders and bear against the faces on both cylinders. The
steam passes through them from the one cylinder to the other in a
straight or nearly straight line, without filling any steam chest or space
further than the passages through the valves and the short ports of
the low-pressure cylinder. The passages through the valves may also
be made to be always filled with steam from the high-pressure cylinder
so that only the short ports of the low-pressure cylinder require to be
filled when the steam is admitted by the valves to the low-pressure
cylinder, thus preventing the great loss of pressure in the steam when
passing from the high to the low pressure cylinder that is usually found
in engines of this kind.
These improved arrangements for high and
low-pressure engines may be carried out with one valve only between
the two cylinders by having long ports in the usual manner to one
central valve, the motion and manner of passing the steam from one
cylinder to another remaining the same, but the length of the ports
would render the engines less economical in working than by the arrange-
ments herein-before described. In these improved arrangements of
high and low pressure engines the steam is admitted to the first or high-
pressure cylinder by a separate valve or valves worked by an inde-
pendent motion from an eccentric, or by any of the methods herein-before
described, and it is preferred to have an adjustable motion in connection
with the valves so as to cut off the steam at different parts of the stroke.
The crank of the high-pressure cylinder in these improved arrangements

page_text: may be set at an angular distance in advance of the low-pressure crank
varying from 90 to nearly 180 degrees as is usual in such engines, but
it is preferred to have the crank of the high-pressure engine ranging
from 210 to 230 degrees of the circle in advance of the low-pressure
crank when the engines are going ahead. The high-pressure crank
will therefore be only from 130 to 150 degrees in advance of the low-
pressure crank when the engines are going astern.
Figure 21, Sheet 3, of the accompanying Drawings is a sectional
elevation of a pair of inverted cylinder engines where the valves that
pass the steam from the high-pressure cylinder to the low-pressure
cylinder also effect the exhaust from the low-pressure cylinder. The
valves have their faces bearing against both cylinders, and the manner
in which the steam passes through the valve from one cylinder to another
is clearly shewn by the Drawing.
Figures 22 and 23 on same Sheet, are respectively a sectional elevation
and plan of a pair of inverted cylinders with the improved arrangement
of valves, the exhaust from the low-pressure cylinder being effected by
separate valves working across the cylinder. The valves for passing
the steam from the high to the low pressure cylinder are in this
instance worked by eccentrics on the crank shaft in the usual manner,
the exhaust valves being worked through levers from two suitably shaped
grooved pieces o, o, carried by the valve spindle as previously described.
Figures 24 and 25, also shew in detail this arrangement for working the
exhaust valves from the other valve's spindle. In this case the scroll
grooves p, p, are on the ends of the levers q, q, and the pins or rollers r, r,
are carried by the valve spindle s. In this arrangement the valves
between the two cylinders may be filled with steam in their box insides
for the purpose of keeping them hot in order to preserve the steam
from loss of heat in passing through them, the cylinders being surrounded
and the covers and pistons filled with steam for the same purpose when
desired, suitable means being provided for admitting the steam to the
covers, pistons, and valves.
Having now particularly described and ascertained the nature of my
said Invention, and the manner in which the same is or may be carried
into effect, I may observe that I do not confine or restrict myself to
the precise details or arrangements which I have had occasion to describe
or refer to in connection with the accompanying Drawings, as it is

page_text: vident that these may be varied within certain limits without departing
rom the principles or main features of my Invention.
In witness whereof, I, the said James Howden, have hereunto
set my hand and seal, this Tenth day of December, in the
year of our Lord One thousand eight hundred and sixty-
eight.
JAMES HOWDEN. (L.S.)