Improvements in Valves and Valve Gear for Steam and other Engines Worked by Fluid Pressure.
Year: 1891

page_text: Date of Application, 26th Jan., 1891
Complete Specification Left, 26th Oct., 1891-Accepted, 28th. Nov., 1891
TROYINIVAATI
Improvements in Valves and Valve Gear for Steam and other
Engines Worked by Fluid Pressure.
JOHN DOUGLAS, 22 Clifton Gardens Chiswick, in the County of Middlesex,
Engineering Draughtsman do hereby declare the nature of this invention to be as
follows:-
My invention has reference to valves for controlling the admission and emission
of steam or other working fluid to the cylinders of steam and other engines operated
by fluid pressure, and a method of working these valves.
My improvements have reference to single or double acting engines; and consist
in placing cylindrical valves at the top and bottom ends of the cylinder, working in
a recess in the cylinder covers, having an angular or rotary movement giving
admission and emission alternately through a number of ports or ways in their
circumference. The steam or other working agent is led to and away from the
cylinder by passages in the cylinder covers, and in the case of steam such covers
doing duty as steam chests and forming jackets to the cylinder ends. The admission
passages in the covers are separate from the emission, and the clearances are reduced
to.a minimum.
Myldevice for getting the valve motion, is a system of levers put into movement
bya pin fixed to the connecting rod of the engine. But the action and arrangement
will be best seen on reference to the figures.
A pin. A fixed in the connecting rod E or in a prolongation of the rod, carries a
thimble or block which works in a slot in the lever B. This lever is suspended and
has for its fulcrum a pin C, fixed to any convenient point, such as the engine
framing; the top end of the lever B has a ball joint. D, and gives movement derived
from the connecting rod E to the levers F and G: The lever F has another
limb Hand through the spindle Kand levers L, M, N and O the valve Pat the
top end of one cylinder is moved simultaneously with the valve Q at the bottom
end of therother cylinder. It will thus be seen that the motion of the connecting
rod works the bottom valve of its own engine and the top valve of the other.
The arrangement of engines as shewn by the figures may be modified.
And :-
:-
In two or more engines, the connecting rod of one engine may or may not give
motion to the valve of the other as is desirable.
One method among others that may be used is -For engines requiring governing
under change of loads, the fulcrum C of the lever 13 would not be fixed, but would
be carried by a link or lever, under the control of the engine governor and so
varying the position of the fulcrum, thereby altering the, cut off of the valves to
suit the varying power required.
In the case of reversing the direction of the running of the engines, the pin C
would not necessarily as is shewn, be fixed in the connecting rod, but may be, by a
suitable gearing moved to astern or ahead position in a frame or other suitable
device fixed to the connecting rod-other devices.may also be used for this purpose.
The form of the slot in the lever will be such as to give any desired cut off
&c. &c., thereby rendering any auxiliary valve for these purposes unnecessary.
This lever B may be solid (instead of a slot) with a block or rollers working on its
outside faces.
Where applicable this form of gear may be used with any other form of valve,
and other devices may be used to give the desired motion to the valves.
Dated this 24th day of January 1891.

page_text: COMPLETE SPECIFICATION.
Improvements in Valves and Valve Gear for Steam and other
Engines Worked by Fluid Pressure.
I, JOHN DOUGLAS of 46 Holly Road, Chiswick in the County of Middlesex,
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :—*
My invention relates to the valves and valve gear of fluid pressure engines, and
is intended to improve the construction of the same and thereby to increase the
efficiency of the engines.
My said invention is applicable to single or double acting engines, and to simple
or compound engines, that is to say to engines having one two or more cylinders
whether working simple or compound.
In
The chief feature of my said invention relates to the distributing valve or valves.
According to this part of my improvements I provide a hollow cylindrical valve or
valves and place it or them in the cylinder cover or covers, so arranging the same
that the clearance space is reduced to an extremely small fraction of the cylinder
capacity. The ports are very short, and open direct on to the piston, and the
admission ports or passages are separate from the emission ports or passages.
steam engines this is very advantageous as the cooling effect of the exhaust steam
on the walls of the admission ports experienced in those engines where the same
ports are used for both admitting and emitting the steam is thereby avoided. My
said valves are or may be perfectly balanced, and the power required to drive them
thus reduced to a minimum.
Another important feature of my invention relates to the gear for operating the
valves. According to one method I derive the required motion from the connecting
rod, by very simple gear which is much easier to work than is the old form of
excentric gear. According to another method, I drive the valves direct from the
piston rod. In either case I obtain a very perfect valve motion and one that admits
of simple and easy adjustment to suit different loads. In my said valve gear, I
provide suitable devices for reversing the engine if necessary.
In the accompanying drawings I have shown the application of my invention to
a two-cylinder compound steam engine, the cylinders being placed side by side and
working on separate cranks.
Figure 1 is a longitudinal central section,
Figure 2 is a side elevation, partly in section, and
Figure 3 is a plan showing a half section through the cylinder, and a half section
through the cylinder cover or valve box, a part of the cylinder being also broken
away of one form of engine constructed according to my invention.
Figure 4 is a longitudinal central section, and
Figure 5 is a plan of one of the distributing valves, drawn to a larger scale.
Figure 6 is an elevation of two cylinders having a modified form of valve gear,
constructed according to my invention, a part of the cylinder being broken away to
show the valves and valve gear.
Figures 7, 8 and 9 are elevational and end views respectively, drawn to a larger
scale of the sleeve shown in Figure 6 employed for giving motion to the valves.
Figure 10 is a plan of one of the valves with the actuating sleeve shown in
dotted lines.
Figure 11 is a front elevation,
Figure 12 is a plan, and
Figure 13 is an end elevation of a reversing gear hereinafter described..
Like letters of reference indicate corresponding parts throughout the drawings.
A is the framing of the engine; B is the high pressure cylinder; and B₁ the low
pressure cylinder; C is the piston, D the piston rod, E the crosshead, F the cross-

page_text: head guides, G the connecting rod and H the crank, all belonging to the' high
pressure cylinder; and C, D, E, F, G, and H¹ are the corresponding parts
pertaining to the low pressure cylinder. I is the crank shaft, J is the fly wheel,
and K is the governor. These parts except as hereinafter described are constructed
as heretofore.
The cylinders are cast together for convenience, and are provided with the usual
admission and emission ports or passages for the steam. a is the inlet for steam
leading to both ends of the small cylinder by passages a', and b is the outlet from
the large cylinder, communicating with both ends of the said cylinder by
passages The cylinder covers care of peculiar construction being divided into
upper and lower compartments by a central transverse web or partition d. These
compartments serve as steam chests, and also do duty as jackets for the cylinder
ends. Each cover is also formed with a central opening e for receiving the
distributing valve, one such valve being placed at each end of the cylinder: The
said openings or valve chambers e communicate directly with the interior of the
cylinders, and in their walls are provided suitable port holes The valve chambers
may be bored out to receive the valves, but preferably they are fitted with
removable tubular linings e¹ the ports of which can be much more accurately and
conveniently finished than could the ports in the walls of the chamber e. I provide
a number of narrow ports instead of one large one, thereby obtaining all the
advantages possessed by the ordinary flat gridiron valve. The steam and' exhaust
ports are arranged to alternate with each other, and all the steam ports are
constructed to communicate with one division or compartment of the corresponding
cylinder cover, while the exhaust ports communicate with the other division or
compartment of the cover. In the illustrations, Figures 1 and 3, I have shown
valves having six steam and six exhaust port openings, the former communicating
with the inner compartments of the covers, and the latter with the outer compart-
ments. e, e are the steam ports or passages, and e³, e³ are the exhaust ports. The
desired communications are formed by suitably shaping the division walls d of the
covers. The inner or steam compartments of the small cylinder communicate
with the steam inlet a by means of the passage a', and the outer or exhaust com-
partments d of the said small cylinder communicate by means of thoroughfares f
with the inner or steam compartments d' of the lare cylinder, while the outer or
exhaust compartments of the latter cylinder communicate by means of the
passages with the steam outlet, b.
The passages a¹, are preferably extended some considerable distance around
their respective cylinders so as to afford good sized thoroughfares for the passage
of the steam. The lower cylinder covers are shown as being cast in one piece, but
they may be cast separately if so desired.
The valves g are hollow and cylindrical and of the gridiron type, having port
holes provided in their circumferential walls. The valves fit the said chambers e,
or the lining e if a lining is employed. They may have a continuous rotary
motion and be driven by gear wheels for example from the crank shaft, or they
may have a rocking or oscillatory motion. I prefer the latter motion, and in the
Figures 1 to 3 I have shown one means that I sometimes adopt for operating the
valves in this manner: On a pin 4 which is capable of a short up and down sliding
movement in a claw shaped bearing ¹ formed in the engine frame I pivot for each
engine a lever 42. The said lever is formed with a curved slot 3 which embraces a
pin or stud fixed in the connecting rod. The said stud as it moves up and down
with the connecting rod traverses the slot and thereby causes the lever to vibrate
about its pivot. The said lever is formed with a short arm h which is connected
by a link i, and lever to the lower end of a vertical shaft or spindle 2 which is
carried by suitable bearings fixed on the cylinder. At the upper and lower ends
of the spindle are fixed other arms which by links and arms are coupled to
short vertical spindles carried in bearings is on the cylinder covers. To these
said spindles are fixed at their inner ends short levers having a slot engaging a
pin g on the valves, in such a manner that the levers will act to oscillate the valves.

page_text: By the above described connections, it will be seen that the vibratory motion of the
lever due to the movement of the pin within the slot ³ is converted into a
vibratory or oscillatory motion of the valves. In the engine shown in Figures 1
to 3 the cranks are on the opposite centres, and the gear is arranged so that the pin
of the connecting rod of one engine actuates the top valve of that engine and the
bottom valve of the other engine. It is obvious however that I can with equal ease
arrange that each spindle shall drive the two valves of its own cylinder.
As above stated the pin is capable of vertical movement in its bearing, the
object of such movement being to provide for varying the cut off according to the
requirements of the load. The said pin is supported by a pair of levers one end
of each of which is connected to the pin, the other end being pivoted at to the
engine frame. is a link, the upper end of which is connected by a pin to the
levers and the lower end of which is coupled at to a lever which is pivoted
at to the engine frame. The lever is connected with and is operated by the
governor K so that any changes in the position of the governor balls is transmitted
through the aforesaid connections and raises or lowers the levers thus altering the
position of the pivot hand of the lever ². The relative positions of the pins h
and at any point are thereby changed as the governor moves in and out, and the
throw of the valve is thus altered, thereby varying the cut off. Owing to the
special shape of the curved slot this alteration of the throw of the valves is
effected within certain limits without altering the lead, and thus provision is made
for regulating the steam supply according to the requirements of the load in a very
efficient manner. I prefer to make the link adjustable for length by any
suitable or well known means, and also to provide a pin and slot connection between
the said link and the lever j so that the effect on the valves may be varied.
For an engine that is required to drive a fairly constant load, I dispense with
the variable cut-off gear and mount the pin 4 in a simple fixed bearing. Or where
an automatically variable cut off is not required may still provide a movable
pivot so that the position of the cut off may be changed by hand when desired.
I reduce the cavities in the valves at one end by constructing the piston rod
stufling boxes to enter and partially fill the same, and at the other end by means of
suitably shaped caps or covers c¹.
One
In the above described valve gear, the point of cut off is governed by the shape
of the slot 3 which may be designed to suit any requirement, and this in connection
with the movable pivot 4 dispenses with any auxiliary valve for this purpose.
Instead of employing a slotted lever, I may use a solid lever, in which case I
provide a block or rollers or the like for embracing the lever in lieu of the pin .
By another method, 1 sometimes drive the valves direct from the piston rod.
One such driving arrangement is shown in Figures 6 to 10. In this arrangement,
each valve is provided with internal tooth like projections g, y3 adapted to engage
with ribs or projections formed on a sleeve & which is fixed on the piston rod.
such sleeve is provided for working each valve. The said ribs are so shaped and
disposed as to move the valves in the desired manner to admit steam, cut off,
release to exhaust and close to exhaust in regular sequence, and all the said
movements are effected positively so that the valves cannot move erratically. As is
clearly shown in Figures 7, 8 and 10, each sleeve is provided with four ribs or
projections,,,, and the valve is provided with two tooth-like projections g²
on one side, and two similar projections on the other side, adapted to engage with
the aforesaid ribs on the sleeve, and when so engaged to be locked thereby to
prevent the valve from rotary movement. During the first portion of the stroke
when the valve is fully open to steam, the rib k¹ is engaged with the projections
and the valve is locked thereby. As the piston continues its movement, the rib k
which is a short one eventually leaves the teeth 2 and the rib on the other side
of the sleeve becomes engaged with one of the teeth. This rib is formed with
two curves, °, as shown in Figure 7, and the first curve operates to turn the
valve sufficiently to shut off the steam, while the second curve turns the valve
still further and opens to exhaust. During the expansion period the valve is held

page_text: by the two ribs ³ ³ which embrace the teeth g³ on the valve, but the rib 4 stops
short at the point of release and enables the curved part of the rib 2 to operate
the valve to effect the release. During the return stroke, the valve is locked by
the straight rib 3 which then traverses the space between the teeth until the
compression point is reached, at which point the rib 3 stops short and the fourth
rib which is curved as shown comes into action and operates on one of tlic
teeth to first close the valve to exhaust and then by further turning it to open
the same to steam.
I provide an extended chamber or pocket on each cylinder cover to receive
and enclose the sleeves k. that pocket through which the piston rod passes being
provided with an ordinary stuffing-box as usual.
If desired, the sleeves & may be dispensed with, the ribs or projections k³, k², k³, k*
being then formed on the piston rod.
If it is desired to reverse the engine, I may provide for doing this by arranging
the pin in Figure 1 so that it can be moved in a frame or other suitable device
to an astern or ahead position, for example, I may fix it to an arm forming a
prolongation of the connecting rod. This plan, however, is objectionable because
of the increased space taken up thereby, and I prefer therefore to provide for
reversing by a more convenient arrangement as follows.
Referring to Figures 11 to 13, i, are the links which communicate rocking
motion to the vertical spindles but instead of being connected to the said spindles
by the arms as described with reference to Figures 1 to 3 they are connected as
hereinafter described, that is to say, the links are forked at their ends as at m and
in each limb of the fork is mounted a block n. The forked ends of each link
embraces a double ended lever o fixed upon the corresponding upright spindle i²,
said lever being formed with a recess o' at each end adapted to receive the block n
on the corresponding limb of the fork. The links i can be moved sideways so as
to bring either of their blocks n as may be desired into gear with the lever o and it
is obvious that when so changed from one side to the other the motion of the
valves will be reversed and the engine will therefore run in the opposite direction.
When the forked links occupy a central position with respect to the double ended
levers 05 both blocks n are disengaged from the said levers o and the valves will
then not be operated. To ensure that the blocks shall always enter the recesses o¹
when reversing the engine, I form the said recesses with bell-shaped mouths of such
a length that the two blocks on each fork are not both entirely withdrawn from
their respective recesses o¹ at the same time. The said bell-shaped mouths are
made sufficiently wide to allow of the links i making a full stroke when in the
central position without engaging with the sides of the recesses.
For reversing the engine i, I provide as follows, that is to say, I extend the fork
limbs as shown at m and connect the same by a short cross piece or shaft m² and in
suitable bearing brackets p fixed on the engine frame A. I mount a short reversing
shaft This shaft is formed with a screw threaded portion 7' which is adapted to
screw into one of the brackets p or into a nut fixed to the said bracket. A hand wheel y²
is mounted on the end of the shaft whereby the said shaft can be rotated in either
direction and thus screwed into or out of the said bracket or nut. Loosely mounted on
the shaft is a lever that engages with the cross piece m² of the forked lever, one
such arm being provided for each cross piece. The said arm is prevented from
longitudinal movement on the shafts and m² by adjustable collars 13, m³
respectively. It will be seen from this description that when the hand wheel q² is
rotated, the forked ends of the links i will be moved laterally, and the blocks n on
the same will be moved into or out of the recesses o', thereby reversing the engine
as above described. The forks m are supported in any convenient manner which
adınits of the required motion.
A steam engine fitted with my improved valves and valve gear has many
advantages over other types of engines, among which I may mention the great
saving of space; the very small clearance space in the cylinders; the advantages
derived from having separate inlet and outlet ports, and from having well balanced

page_text: valves, that do not require to have much motion, good steam distribution, and a
variable cut off without the necessity for employing an auxiliary valve, while
ensuring a practically constant lead. My improvements are particularly applicable
to steam engines but they are also advantageous for engines driven by other motive
fluids.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
First: An engine provided with cylindrical distributing valve or valves
arranged in recesses in the cylinder cover or covers.
Second: An engine having a cylindrical oscillating or rotating distributing valve
or valves arranged in the cylinder cover or covers, .substantially as herein
described.
Third. A valve gear for a variable cut-off wherein the motion is. derived. from a
slotted lever engaging a pin on the connecting rod, said lever being so arranged
that by moving its pivot point the cut-off' is varied, substantially as:described.
Fourth. The combination with a cylindrical valve or valves. arranged in. the
cylinder cover or covers, of a valve-gear for a variable cut-off, constructed sub-
stantially as described and illustrated in Figures 1 to 3 of the drawings.
Fifth. The modification of the valve-gear, referred to: in. Claim 4, wherein. the
pivot of the slotted lever is fixed.
Sixth. An engine having a cylindrical valve or valves in the cylinder cover or
covers, and wherein the said valve or valves.is or are operated by means of ribs
formed on the piston rod or on sleeves mounted on the piston rod, substantially as
described.
Seventh. The peculiar reversing gear constructed substantially as described with
reference to Figures 11 to 13 of the drawings, and operating as specified.
Eighth. The engine constructed substantially as described with reference to
Figures 1 to 3 of the drawings and operating as specified.
Dated this 26th day of October 1891.
HASELTINE, LAKE'& Co., .
45; Southampton Buildings, London, Agents for the. Applicant..