IMPROVEMENTS IN APPARATUS FOR Engineer, for WORKING THE VALVES OF STEAM OR WATER PRESSURE ENGINES
Year: 1874

page_text: LETTERS PATENT to Henry Davey, of Leeds, in the County of York,
the Invention of "IMPROVEMENTS IN APPARATUS FOR
Engineer, for
WORKING THE VALVES OF STEAM OR WATER PRESSURE ENGINES."
Sealed the 4th August 1874, and dated the 4th June 1874.
PROVISIONAL SPECIFICATION left by the said Henry Davey at the
Office of the Commissioners of Patents, with his Petition, on the
4th June 1874.
•
I, HENRY DAVEY, of Leeds, in the County of York, Engineer, do
hereby declare the nature of the said Invention of "IMPROVEMENTS IN
APPARATUS FOR WORKING THE VALVES OF STEAM OR WATER PRESSURE ENGINES,"
to be as follows: —
In the Specification of a Patent granted to me on the 1st February
1871, No. 277, I described means of working the slides of steam engines
by the movement of the piston of a subsidiary cylinder controlled by a
cataract, or the adjustable resistance offered to a piston. working in
a cylinder containing liquid.

page_text: My present Invention relates to improvements in the construction
and arrangement of apparatus for this purpose, to means of applying
the slide movement to the working of an expansion valve, and to means
of adjusting the pause at each stroke of a pumping engine, so as to
suit its working to the flow of water in the pumps.
One arrangement of the improved apparatus for working the slide
applicable to a horizontal engine is as follows:-The slide jacket of
the main cylinder being on its upper side I provide a slide facing on
the interior of the cover of the slide jacket with ports leading to the
subsidiary cylinder, which is placed immediately over it, and an exhaust
port communicating with the main exhaust. To this facing I fit a
slide connected to and moving with the main slide, but in an inverted
position. Above the subsidiary cylinder I provide a cataract cylinder
having a channel, governed by a cock or valve, for the passage of the
liquid from the one end of the cylinder to the other. On the lower
part of the engine frame, in front of the main cylinder, I pivot a pair
of levers extending upwards, one on either side of the main piston rod.
Those two levers are connected across by three cross heads jointed to
them. The uppermost cross head is in line with the piston rod of the
cataract cylinder, which is jointed to it. The next lower cross head is
in line with and jointed to the piston rod of the subsidiary cylinder, and
the lowest cross head, which is situated a little below the main slide
rod, forms the fulcrum of a lever, the upper short arm of which is
jointed to the main slide rod, while the long arm extending downwards
is bifurcated, each fork being jointed to a vertical slide fitted on the
side of a head secured to the main piston. As the main piston makes
its stroke in either direction the long arm of the bifurcated lever being
carried onwards with it, the short arm above is moved in the opposite
direction in time with, but more slowly than the main piston. The
main slide is thus moved slowly in a direction opposite to that of the
piston, and the second slide which is connected to it moves with it.. As
the piston approaches the end of its stroke this second slide uncovering
one of the ports of the subsidiary cylinder admits steam from the slide
jacket to one end thereof. Its piston is thereby propelled and moves
the pair of levers to which it is connected with a speed regulated by the
resistance of the liquid in the cataract cylinder to the piston thereof,
which is also connected to the same pair of levers. By the movement
of those levers the main slide is shifted, so as to admit steam to the

page_text: main cylinder at the end which the main piston has reached, and so to
cause it to make its return stroke.
An arrangement of the improved slide apparatus applicable to a
compound horizontal engine where the high-pressure and low-pressure
cylinders are situated, the one behind the other with their axes in the
same horizontal line, is as follows;-The subsidiary cylinder is fixed on
the side of the high-pressure cylinder having its ports communicating
with a slide jacket thereof, and governed by a lateral slide fitted within
the said slide jacket. The cataract cylinder is fixed on the low-pressure
cylinder facing the subsidiary cylinder, the pistons of the subsidiary
cylinder and cataract cylinder being attached to one rod; to this rod is
jointed one end of a lever or pair of levers, which extend transversely
across the engine. About the middle of these levers is jointed to them
a slide rod connecting the high and low pressure slides and the farther
end of the levers is connected by a connecting rod to an upright short
arm of a rocking shaft, from which there is a long arm extending
downwards and connected by a rod to the cross head, to which the
piston rods of the high and low-pressure cylinders are secured. Between
the middle and the outer end of the transverse levers above mentioned
is a link jointed to them, and to the end of another horizontal lever.
The farther end of this lever works on a pivot, which may be fixed in
position, or may be made to move, as will hereafter be described, for the
purpose of regulating the pause of the engines. Between this pivot of
the horizontal lever and its end that is linked to the transverse levers,
the horizontal lever is jointed to the rod of the slide for the subsidiary
cylinder. According to this arrangement the cross heads of the main
pistons, as they make their stroke in either direction, working the
rocking shaft, causes the transverse levers and the lever linked thereto
to oscillate in time with, but in direction opposite to the main pistons,
and much more slowly. The main slide and the slide of the subsidiary
cylinder are thus moved, and the latter as the main pistons approach
the end of the stroke uncovers a steam port of the subsidiary cylinder,
whereby steam is admitted thereto. The subsidiary piston being thus
propelled moves the end of the transverse levers and thereby shifts the
main slide connected to their middle, so as to cause the main pistons to
make their return stroke.
An expansion valve, of double beat form, fitted on the supply pipe of
the high-pressure slide jacket is moved in time with the slide in the

page_text: following manner:-The slide rod works one arm of a three-armed
Jever, the other two arms of which have pins working in slotted holes
in a pair of oblique rods, which are both connected to a lever for
working the double-beat valve. When the slide makes its stroke in the
one direction, one of the arms of the three-armed lever bearing on the
end of the slotted hole in one of the oblique rods causes the valve to
be raised for the admission of steam, and as the slide retreats the valve
again closes. When the slide makes its stroke in the opposite direction
a similar action ensues from the other arm of the lever working in the
'slot of the other rod. The oblique rods are made adjustable in length,
so as to render the opening of the valve greater or less, as may be desired
for the work of the engine.
It has been stated above that the pause of the engine at each stroke
can be regulated by imparting a movement more or less rapid to the
fulcrum of the horizontal lever which works the slide of the subsidiary
cylinder. This is effected in the following manner:-A second sub-
sidiary cylinder and cataract cylinder are placed vertically by the side
of the high-pressure cylinder. The slide of the former is worked from
a lever acted on by a horizontal arm of the rocking shaft mentioned
above; the piston rod of the second subsidiary and cataract cylinders
has on it a rack gearing with a pinion upon a sleeve, which sleeve has
a screw thread cut on it. A nut fitted to this screw carries the pivot
of the horizontal lever above mentioned, and the sleeve is free to turn
on a fixed round bar, but is prevented by collars thereon from moving
lengthwise. When the piston of the second subsidiary cylinder makes
its stroke the speed of which is timed by adjusting the resistance in the
*second cataract cylinder, the sleeve being turned by the action of the
rack and pinion, the nut on the sleeve is caused to move along the
sleeve, and thus the pivot of the horizontal lever is moved, so as to open
the slide of the first subsidiary cylinder sooner or later, and thereby to
cause the movement of the main pistons to be reversed with a shorter or
longer pause at the end of each stroke.
'Apparatus similar to that described above is applicable for working
the slides of engines actuated by water pressure and for regulating the
pause at the end of each stroke of such engines, as may be readily
understood, the apparatus described for working expansion valves being
in such engines dispensed with.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Davey in the Great Seal Patent Office on
the 26th November 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
DAVEY, of Leeds, in the County of York, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of June, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Henry Davey, Her special license, that
I, the said Henry Davey, my executors, administrators, and assigns,
or such others as I, the said Henry Davey, my executors, admini-
strators, 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 APparatus
FOR WORKING THE VALVES OF STEAM OR WATER PRESSURE ENGINES,"
upon the
condition (amongst others) that I, the said Henry Davey, 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 Henry Davey, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the accompanying
Drawings and to the figures and letters marked thereon, that is to
say
-
In the Specification of a Patent granted to me on the 1st February
1871, No. 277, I described means of working the slides of steam engines
by the movement of the piston of a subsidiary cylinder controlled by a
cataract, or the adjustable resistance offered to a piston working in
a cylinder containing liquid.

page_text: My present Invention relates to improvements in the construction
and arrangement of apparatus for this purpose, to means of applying
the slide movement to the working of an expansion valve, and to means
of adjusting the pause at each stroke of a pumping engine, so as to
suit its working to the flow of water in the pumps.
One arrangement of the improved apparatus for working the slide
applicable to a horizontal engine is as follows:-The slide jacket of
the main cylinder being on its upper side I provide a slide facing on
the interior of the cover of the slide jacket with ports leading to the
subsidiary cylinder, which is placed immediately over it, and an exhaust
port communicating with the main exhaust. To this facing I fit a
slide connected to and moving with the main slide, but in an inverted
position. Above the subsidiary cylinder I provide a cataract cylinder
having a channel governed by a cock or valve for the passage of the
liquid from the one end of the cylinder to the other. On the lower
part of the engine frame in front of the main cylinder I pivot a pair
of levers extending upwards one on either side of the main piston rod.
These two levers are connected across by three cross heads jointed to
them. The uppermost cross head is in line with the piston rod of the
cataract cylinder which is jointed to it. The next lower cross head is
in line with and jointed to the piston rod of the subsidiary cylinder, and
the lowest cross head, which is situated a little below the main slide
rod forms the fulcrum of a lever, the upper short arm of which is
jointed to the main slide rod while the long arm extending downwards
is bifurcated, each fork being jointed to a vertical slide fitted on the
side of a head secured to the main piston. As the main piston makes
its stroke in either direction the long arm of the bifurcated lever being
carried onwards with it the short arm above is moved in the opposite
direction in time with but more slowly than the main piston.
main slide is thus moved slowly in a direction opposite to that of the
piston, and the second slide which is connected to it moves with it. As
the piston approaches the end of its stroke this second slide uncovering
one of the ports of the subsidiary cylinder admits steam from the slide
jacket to one end thereof. Its piston is thereby propelled and moves
the pair of levers to which it is connected with a speed regulated by the
resistance of the liquid in the cataract cylinder to the piston thereof,
which is also connected to the same pair of levers. By the movement
of those levers the main slide is shifted so as to admit steam to the
•
The

page_text: main cylinder at the end which the main piston has reached, and so to
cause it to make its return stroke.
An arrangement of the improved slide apparatus applicable to a
compound horizontal engine where the high-pressure and low-pressure
cylinders are situated, the one behind the other, with their axes in the
same horizontal line, is as follows:-The subsidiary cylinder is fixed on
the side of the high-pressure cylinder having its ports communicating
with a slide jacket thereof and governed by a lateral slide fitted within
the said slide jacket. The cataract cylinder is fixed on the low-pressure
cylinder facing the subsidiary cylinder, the pistons of the subsidiary
cylinder and cataract cylinder being attached to one rod. To this rod is
jointed one end of a lever or pair of levers which extend transversely
across the engine. About the middle of these levers is jointed to them
a slide rod connecting the high and low pressure slides, and the farther
end of the levers is connected by a connecting rod to an upright short
arm of a rocking shaft, from which there is a long arm extending
downwards and connected by a rod to the cross head to which the
piston rods of the high and low pressure cylinders are secured. Between
the middle and the outer end of the transverse levers above mentioned
is a link jointed to them and to the end of another horizontal lever.
The farther end of this lever works on a pivot which may be fixed in
position or may be made to move, as will hereafter be described, for the
purpose of regulating the pause of the engines. Between this pivot of
the horizontal lever and its end that is linked to the transverse levers,
the horizontal lever is jointed to the rod of the slide for the subsidiary
cylinder. According to this arrangement the cross heads of the main
pistons as they make their stroke in either direction, working the
rocking shaft, causes the transverse leverse and the lever linked thereto
to oscillate in time with but in direction opposite to the main pistons,
and much more slowly. The main slide and the slide of the subsidiary
cylinder are thus moved, and the latter as the main pistons approach
the end of the stroke, uncovers a steam port of the subsidiary cylinder,
whereby steam is admitted thereto. The subsidiary piston being thus
propelled moves the end of the transverse levers, and thereby shifts the
main slide connected to their middle, so as to cause the main pistons to
make their return stroke.
An expansion valve, of double beat form, fitted on the supply pipe of
the high-pressure slide jacket is moved in time with the slide in the

page_text: following manner:- -The slide rod works one arm of a three-armed
lever, the other two arms of which have pins working in slotted holes
in a pair of oblique rods which are both connected to a lever for
working the double beat valve. When the slide makes its stroke in the
one direction one of the arms of the three-armed lever bearing on the
end of the slotted hole in one of the oblique rods causes the valve to
be raised for the admission of steam, and as the slide retreats the valve
again closes. When the slide makes its stroke in the opposite direction
a similar action ensues from the other arm of the lever working in the
slot of the other rod. The oblique rods are made adjustable in length
so as to render the opening of the valve greater or less, as may be desired
for the work of the engine.
.
It has been stated above that the pause of the engine at each stroke
can be regulated by imparting a movement, more or less rapid, to the
fulcrum of the horizontal lever which works the slide of the subsidiary
. cylinder. This is effected in the following manner:-A second sub-
sidiary cylinder and cataract cylinder are placed vertically by the side
of the high-pressure cylinder. The slide of the former is worked from
a lever acted on by a horizontal arm of the rocking shaft mentioned
above; the piston rod of the second subsidiary and cataract cylinders
has on it a rack gearing with a pinion upon a sleeve, which sleeve has
a screw thread cut on it. A nut fitted to this screw carries the pivot
of the horizontal lever above mentioned, and the sleeve is free to turn
on a fixed round bar, but is prevented by collars thereon from moving
lengthwise. When the piston of the second subsidiary cylinder makes
its stroke, the speed of which is timed by adjusting the resistance in the
second cataract cylinder, the sleeve being turned by the action of the
rack and pinion, the nut on the sleeve is caused to move along the
sleeve, and thus the pivot of the horizontal lever is moved so as to open
the slide of the first subsidiary cylinder sooner or later, and thereby to
cause the movement of the main pistons to be reversed with a shorter or
longer pause at the end of each stroke.
Apparatus similar to that described above is applicable for working
the slides of engines actuated by water pressure, and for regulating the
pause at the end of each stroke of such engines, as may be readily
understood, the apparatus described for working expansion valves being
in such engines dispensed with.

page_text: Fig. 1, Sheet I., represents a longitudinal and Fig. 2 a transverse
section of a horizontal steam engine cylinder and slide, with means of
working the latter according to my Invention; G is the main cylinder
of the engine, with its piston F and piston rod F' of usual construction.
On the piston rod F is fixed a head D having on each side a vertical
slot, in which works a slide carrying a pin D', to which is jointed a
lever E forked over the head D. This lever works on a pin E' as a
fulcrum, and its shorter end E" is connected to the slide rod A which
works the two slides A and B facing opposite ways within the jacket A'
supplied with steam by the inlet A". The fulcrum E' is a cross head
connecting two parallel levers H which works on pins H' on each side
of the engine frame. The upper part of the levers H are connected by
a cross head H" to the rod of the piston C working in the subsidiary
cylinder C, and by a cross head H to the rod of the piston M working
in the cataract cylinder M' charged with water or other liquid and
having a communicating passage M" from the one end of the cylinder
to the other, which passage can be more or less closed by stop cocks or
valves at M. The slide A, of the ordinary D kind, governs the ports
to either end of the cylinder G and the eduction passage B". The slide
B is of similar description, governing the ports of the cylinder C₁ and
its eduction passage B', which communicates with the main eduction B":
In Fig. 1 the slides A and B are shewn in their middle position, the
main piston F approaching the extreme of its in stroke, the farther move-
ment of the piston F with its head D drawing the end D' of the lever E
towards the left causes the opposite end E" to move a little towards the
right, and thereby moves the slide B so as to open the left-hand port of
the cylinder C' to the steam and its right-hand port to the exhaust.
The piston C being thus pressed forwards moves the lever H to the
right, carrying forward the fulcrum E' of the lever E, while the lower
end D' of that lever is almost stationary. The upper end E" is thus
moved forwards, moving the slide A so as to admit steam behind the
piston F. This piston then moves forwards, carrying with it the end D'
of the lever E, and thereby gradually moving back the slides A and B
till as the piston approaches the end of its out stroke, the slide B being
moved back to uncover the front port of C', the piston C is forced back,
pushing back the main slide A so as to admit steam in front of the
piston F and to cause it to make its back stroke. The rapidity with

page_text: which the piston C moves is controlled by the resistance of the liquid in
the cataract cylinder M' to the motion of the piston M, and thus the
slide A can be made to uncover the ports of the main cylinder more or
less quickly, according as the passage M" from the one end of the
cataract cylinder to the other end is of greater or less area, as determined
by the adjustment of the cocks or valves M, and in this manner a
pause of less or greater duration is made to take place between the
successive strokes of the piston F. The cylinder M' instead of being
truly bored may be made of somewhat larger diameter at the ends or at
the middle, so that while the piston M travels along the enlarged part
a portion of the liquid may leak past it, and thus the movement of the
slide A may be made more rapid at one part of its stroke.
Figs. 3 and 4, Sheet II., represent respectively a side view and a plan
of part of a compound horizontal pumping engine having its slides and
expansion valve worked according to my Invention.
Figs. 5 and 6, Sheet III., represent respectively to an enlarged scale
a part longitudinal section and a part plan (partially in section) of the
said engine!
Figs. 7 and 8, Sheet III., represent respectively parts of transverse
sections through the low-pressure cylinder and its slide, and through
the slides of the high-pressure cylinder; and Fig. 9, Sheet I., represents
a part transverse section on the line +, + Fig. 4.
The piston rod P of the front or high-pressure cylinder G and the two
piston rods P¹ of the hinder low-pressure cylinder G₁ are secured to the
cross head O to which the connecting rods O" are jointed; an arm O¹
projecting down from the cross head O is connected by a rod to a long
arm N on a rocking shaft N mounted in bearings on the framing of
the engine; a short arm N' on the shaft N is connected by a rod L to
the end E' of a pair of horizontal levers E which have their common
fulcrum at E on a rod C" connecting the piston C of the subsidiary
cylinder C to the piston M of the cataract cylinder M'; at E", about
the middle of the levers E, they are jointed to the rod A¹¹ which
connects the slides A and K of the two cylinders G and G. A pin E
on the levers E is linked to the end H¹ of a lever H having its fulcrum
at H¼ which is capable of being moved by a worm, as will hereafter be
described, but which fulcrum may be considered as being stationary
during the ordinary working of the engine. The lever H is connected

page_text: at H¹ to the rod B of the slide B commanding the ports of the
subsidiary cylinder C¹.
It will be seen that the connections from the cross head O to the
lever E are such that the end E' of the latter is made to move in time
with the pistons but always in the opposite direction, and with a con-
siderably shorter stroke. As the pistons make their out stroke or
towards the left the lever E oscillating towards the right and taking
with it the lever H moves the slide B so as to open to the steam the
left-hand port of the cylinder C₁, the piston C is then forced towards the
right with a speed controlled by the resistance offered to the piston M
by the liquid in the cataract cylinder M' which is regulated by adjusting
a screw plug M in the passage M". The piston C moving towards the
right the end E"" of the lever E causes the middle E" of that lever also
to move towards the right and thus moves the slides A and K. A like
action ensues during the return strokes of the pistons..
111
In order to work the high-pressure cylinder expansively a double beat
valve I in the steam pipe is worked in accord with the movement of the
slide as follows:-The slide rod A prolonged through a stuffing box
beyond the slide jacket works a lever R having two arms R' and R"
which have pins working in slots P' of two oblique rods P, both jointed
to the valve lever Q and both provided with adjusting nuts P" by which
the lift of the valve I can be regulated.
It will be seen that both in the forward and the back strokes of the
slide A the valve I is raised to admit steam. An eccentric lever Qu can
be turned by band so as to render the stroke of the lever Q ineffective to
raise the valve I, in which case the engine is stopped.
In the preceding description the fulcrum H" was assumed to be
stationary. I will now describe my contrivance for giving the fulcrum H"
a movement whereby the movement of the slide B can be timed so as
to produce a longer or shorter pause at the end of each stroke of the
engine, such as is found useful in pumping engines. An arm N™ on
the rocking shaft N is connected by a rod U to one end of a lever V,
the other end of which is connected to a lever working the slide of a
small steam cylinder Z similar to the subsidiary cylinder C¹ and like it
fitted with a piston, the rod of which is connected to the piston of a
cataract cylinder Y provided like the cataract cylinder M' with an
adjusting plug for regulating resistance. The piston rod X of the

page_text: cylinders Y and Z continued upwards has a rack which gears with a
pinion W on a sleeve W mounted on the round bar W¹ between collars
so that it can turn but cannot slide on the bar; on the sleeve W¹¹¹ is a
worm W embraced by a nut on which is the fulcrum pin H" of the
lever H. The shaft N being caused to rock by its connection with the
cross head O the lever V is also caused to oscillate and to move the slide
of the cylinder Z, whereby the rack rod X is caused to ascend and
descend with a speed determined by the resistance in the cataract
cylinder Y and to turn the pinion and the worm W" in opposite direc-
tions alternately, moving the nut and fulcrum H" alternately to the
right and left, thus governing the movement of the secondary slide B
and the consequent shift of the main slides A and K.
It may be readily understood that mechanism similar to that which I
have described for steam engines is applicable for like purposes to
engines worked by water pressure.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I hereby declare that I make no
general claim to the working of valves of steam or water-pressure
engines by means of a subsidiary piston controlled by a cataract, but I
claim,―
First. The use for the purpose of working the slide of an engine by a
subsidiary piston controlled by a cataract, of apparatus constructed and
operating substantially as described in reference to Figs. 1 and 2 of the
accompanying Drawings, wherein one lever H worked by the subsidiary
piston and controlled in its movement by the cataract piston carries the
fulcrum of another lever E worked by the main piston, and working
simultaneously the main slide and the subsidiary slide.
Second. The use for the purpose of working the slides of a compound
engine by a subsidiary piston controlled by a cataract, of apparatus con-
structed and operating substantially as described in reference to Figs. 2,
3, 4, 5, 6, 7, 8, and 9 of the accompanying Drawings, wherein one
lever H working the subsidiary slide is connected by a link to another
lever E working the main slides, the latter lever being moved at the one
end by a connection to a rocking shaft worked by the main pistons, and
and at the other end by the subsidiary piston controlled by a cataract.
Third. The use in combination with the apparatus, which forms the
subject of the second claim, of a second subsidiary steam and cataract

page_text: cylinder for shifting the fulcrum of the lever H for the purpose of
varying the pause at each stroke of the main pistons, substantially as
herein described.
Fourth. The use in combination with the apparatus, which forms the
subject of the second claim of apparatus, for working an expansion valve
from the main slide, so constructed and arranged that at each stroke of
the slide in either direction the expansion valve is opened to an extent
and for a time that can be regulated by adjusting screws, substantially
as herein described.
In witness whereof, I, the said Henry Davey, have hereunto set
my hand and seal, this Twenty-first day of November, in the
year of our Lord One thousand eight hundred and seventy-
four.
HENRY DAVEY. (L.S.)