IMPROVEMENTS IN STEAM ENGINES AND IN DIRECT-ACTING STEAM PUMPING ENGINES
Year: 1875

page_text: LETTERS PATENT to Henry Cherry, of Aston, near Birmingham, in
the County of Warwick, Mechanical Engineer, for the Invention
'
of "IMPROVEMENTS IN STEAM ENGINES AND IN DIRECT-ACTING STEAM
PUMPING ENGINES."
Sealed the 28th April 1876, and dated the 16th November 1875.
PROVISIONAL SPECIFICATION left by the said Henry Cherry at the
Office of the Commissioners of Patents, with his Petition, on the
16th November 1875.
I, HENRY CHERRY, of Aston, near Birmingham, in the County of
Warwick, Mechanical Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN STEAM ENGINES AND IN DIRECT-ACTING
STEAM PUMPING ENGINES," to be as follows:-
My Invention consists, first, of the following arrangement of the parts
of cut-off valves for steam engines capable of being controlled by the
governor of the engine or regulated by hand.

page_text: ;
I prefer to construct and arrange the parts in the following manner :—
The release, compression, and commencement of admission of the steam
to the cylinder are effected by the motion of a slide valve, herein-after
called the main valve. The time or portion of the stroke during which
.steam is admitted to the cylinder is controlled by the motion of a cut-off
valve working on the back of the main valve. The main valve has the
passages through which the steam passes to the cylinder continued
through it from front to back, so that when the cut-off valve covers one
or the other of the ports formed by these passages at the back of the
main valve the admission of steam is stopped or cut off from the cor-
responding end of the cylinder. The cut-off valve is moved by steam
acting on one or the other of two pistons, which are preferably cast in
one piece, and have their cylinders arranged in a line parallel to the
motion of the cut-off valve. The admission of steam to the said pistons
is controlled by a small slide valve, the spindle of which has a radius
link coupled to it. A pin at the end of the radius link carries a block,
which block works in a slot or groove in a link or lever. By raising or
lowering this block in the groove of the link or lever the point at which
steam is admitted to and exhausted from the cut-off valve pistons is
regulated. The position of the block in the link or lever may readily be
controlled by a rod from the governor. The said link may either receive
motion from one eccentric or two. I prefer to use two eccentrics, as
the range of variation of the cut-off is more readily under control. I
obtain the requisite motion of the link in the following way :-A short
shaft receives a rocking motion from the main valve by means of a lever
fixed to one end of the said shaft. The other end of the shaft has a
short crank arm, the pin of which carries the link.
the link is moved by a separate eccentric and rod.
is V shaped, so that the block has play at the upper end of the slot.
By this means a short motion of the block in the link may be made to
vary the cut-off to any desired extent, and a comparatively weak
governor will control the expansion.
The upper end of
The slot in the link
The steam ports, through which the steam passes to the cut-off valve
cylinders, that is, those ports which the small slide valve opens, are
made very small compared with the corresponding exhaust ports, and
packing rings are placed in the cut-off valve pistons in such positions
that before the pistons reach the end of their stroke the said rings pass
over the holes or ports in the bore of the cylinders, which admit steam

page_text: to and exhaust steam from them. The effect of this arrangement is
that the steam port being small, while the exhaust port is large, the
steam is "wire drawn" by the rapid motion of the pistons, so that the
said pistons take only such.a supply of steam as is necessary to carry
5 them over, and all further access of steam is prevented by the packing
ring or rings passing over the inlet port in the bore of the cylinder.
The steam employed for moving the cut-off valve is thus economised
to the utmost extent. The closing of the exhaust port in the bore of
the cylinder imprisons a sufficiency of steam to cushion the pistons, and
make them work noiselessly. This arrangement possesses the advantage
that the pistons may be made large, so as to give the greatest certainty
of action and margin of power, without employing an excess of steam to
drive them. I obtain the same result by mounting the small slide
valve on the casting of the pistons, as in the arrangement next described,
and drive it in a similar manner to that before described.
My Invention consists further of the following improvements in the
valves of direct-acting steam pumping engines: -I construct the main
valve or valves and port faces which control the admission and émission
of steam from the cylinder with such a configuration of the edges con-
trolling the admission and emission of the steam that a reduction in the
length of stroke of the valve or valves will reduce the area available for
the admission of steam without affecting that for the emission to a pre-
judicial extent.
I construct the subsidiary valve or valves which control the admission
and emission of steam to the piston or pistons which move the main
valve or valves controlling the admission of steam to the cylinder and
the gear for moving the said subsidiary valve or valves in such a manner
that while the main piston travels its normal stroke the main valve
travels its full stroke; but if the main piston travel beyond its normal
distance the travel of the main valve is reduced, and the area available
for the admission of steam is reduced also.
I construct the steam cylinder double, that is, with a smaller cylinder
within it, which smaller cylinder has a casing surrounding it, forming a
steam jacket. There are two pistons, one annular, with packings working
steam-tight in the bore of the large cylinder, and outside the casing of
the smaller cylinder. The other piston works in the smaller cylinder.
The main valve or valves, while admitting steam to the front end of the

page_text: smaller cylinder, allow the steam from the back end to exhaust into the
front annular space of the larger cylinder, and on the pistons making
their stroke the steam is expanded to whatever extent the annular area
exceeds that of the smaller piston. Similarly for the return stroke the
steam is admitted to the back end of the smaller cylinder, and the steam
from the front end exhausts into the back annular space. The steam from
the annular space may exhaust into the atmosphere or into a condenser
or otherwise.
I carry out these improvements in the following manner :-On the
steam cylinder I bolt the steam chest containing the main slide valve in
the usual way.
The steam chest is bored out at each end to receive the
pistons which move the main valve. I cast these pistons in one piece,
and place the subsidiary valve that admits steam to them on the con-
necting part of the casting. The subsidiary valve is held between fixed
guides, so that it cannot move with the said pistons, but can move at
right angles to their motion, and is moved by tappets or levers by the
main pistons. The ports and passages for the admission and exhaustion
of steam from the said pistons are formed in their casting, and I shape
the edges and exhaust cavity of the said subsidiary valves in such a
manner that in normal working the steam is cut off and the exhaust
opened to the said pistons at such points in the stroke that the main
valve shall travel its normal stroke, but if the main piston travel beyond
its normal distance then the subsidiary valve will receive a longer travel,
and its edges and exhaust cavity will be so disposed that the steam will
be cut off earlier, and the exhaust opened earlier to the pistons which
move the main slide valve, thus shortening its stroke.
It will be understood that the motion of the subsidiary valve across
the said pistons opens the steam and exhaust ports to the said pistons,
while the motion of the said pistons beneath the subsidiary valve cuts
off the steam from the piston taking steam; and opens the exhaust
to it.

page_text: -
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Cherry in the Great Seal Patent Office on
the 12th May 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
CHERRY, of Aston, near Birmingham, in the County of Warwick,
Mechanical Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of November, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Henry Cherry, Her special
license that I, the said Henry Cherry, my executors, administrators, and
assigns, or such others as I, the said Henry Cherry, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and. Isle of Man, an Invention for "IMPROVEMENTS IN
STEAM ENGINES AND IN DIRECT-ACTING STEAM PUMPING ENGINES," upon the
condition (amongst others) that I, the said Henry Cherry, 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 Cherry, 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, that is to say:
My Invention consists first of the following arrangement of the parts
of cut-off valves for steam engines, capable of being controlled by the
governor of the engine or regulated by hand.
I prefer to construct and arrange the parts in the following manner :—
The release, compression, and commencement of admission of the steam

page_text: to the cylinder are effected by the motion of a slide valve herein-after
called the main valve. The time or portion of the stroke during which
steam is admitted to the cylinder is controlled by the motion of a cut-
off valve working on the back of the main valve. The main valve has
the passages through which the steam passes to the cylinder continued
through it from front to back, so that when the cut-off valve covers one
or the other of the ports formed by these passages at the back of the
main valve, the admission of steam is stopped or cut off from the
corresponding end of the cylinder. The cut-off valve is moved by steam
acting on one or the other of two pistons, which are preferably cast in
in one piece and have their cylinders arranged in a line parallel to the
motion of the cut-off valve. The admission of steam to the said pistons
is controlled by a small slide valve, the spindle of which has a radius link
coupled to it. A pin at the end of the radius link carries a block which
block works in a slot or groove in a link or lever. By raising or lowering
this block in the groove of the link or lever, the point at which steam is
admitted to and exhausted from the cut-off valve pistons is regulated.
The position of the block in the link or lever may readily be controlled
by a rod from the governor. The said link may either receive motion
from one eccentric or two. I prefer to use two eccentrics as the range
of variation of the cut off is more readily under control. I obtain the
requisite motion of the link in the following way:-A short shaft
receives a rocking motion from the main valve by means of a lever fixed
to one end of the said shaft; the other end of the shaft has a short
crank arm, the pin of which carries the link. The upper end of the
The slot in the link
link is moved by a separate eccentric and rod.
is V shaped, so that the block has play at the upper end of the slot. By
this means a short motion of the block in the slot of the link may be
made to vary the cut off to any desired extent, and a comparatively
weak governor will control the expansion.
The steam ports through which the steam passes to the cylinders of the
cut-off pistons, that is, those ports which the small slide valve opens are
made very small compared with the corresponding exhaust ports, and
packing rings are placed on the cut-off valve pistons in such positions that
before the pistons reach the end of their stroke the said rings pass over
the holes or ports in the bore of the cylinders, which admit steam to
and exhaust steam from them. The effect of this arrangement is that
the steam port being small while the exhaust port is large, the steam is

page_text: "wire drawn " by the rapid motion of the pistons, so that the said
pistons take only such a supply of steam as is necessary to carry them
over, and all further access of steam is prevented by the packing ring
or rings passing over the inlet port in the bore of the cylinder. The
steam employed for moving the cut-off valve is thus economized to the
utmost extent. The closing of the exhaust port in the bore of the
cylinder imprisons a sufficiency of steam to cushion the pistons and
make them work noiselessly. This arrangement possesses the advantage
that the pistons may be made large, so as to give the greatest certainty
of action and margin of power without employing an excess of steam to
drive them. I obtain the same result by mounting the small slide valve
on the casting of the pistons, as in the arrangement of direct acting
steam pumping engine herein-after described, and drive it in a similar
manner to that before described.
My improvements in cut-off valves for steam engines capable of
being controlled by the governor of the engine or regulated by hand.
are illustrated in Figures 1, 2, 3, and 4 of the accompanying Drawings.
Figure 1 represents a sectional plan of my arrangement of cut-off
valves; Figure 2, a section of the same taken on the line A, B, of
Figure 1; Figure 3 an enlarged section of the same taken on the
line C, D, of Figure 1; and Figure 4 is a section of the same taken on
the line E, F, of Figure 1.
The same letters of reference indicate the same parts in Figures, 1, 2,
3, and 4.
a is the main slide valve; is the cut-off valve working on the back
of the said main valve a; c, c, are the passages in the main valve a,
through which steam passes to the cylinder. These passages pass from
front to back, and when the cut-off valve covers either of the ports
formed by these passages at the back of the main valve, steam is cut
off from the corresponding end of the steam cylinder. d, d, are the
pistons moving the cut-off valve b; e is the small slide valve controlling
the admission of steam to the pistons d, d; f is the spindle of the slide
valve e, and g is the radius link coupled to it; h is a pin at the end
of the radius link which carries the block i working in a slot or
opening in the link or lever k. The regulation of the cut off is
effected by raising or lowering the block i in the slot or groove j.
7 is a rod from the governor of the steam engine connected with the

page_text: radius link 9. The position of the block i may be changed, and hence
the cut off controlled by means of the said rod l; m is a short shaft
receiving a rocking motion from the spindle w of the main valve a by
means of the lever n fixed at one end of the shaft m; o is a short
crank arm, the pin p of which carries the link k; q is a rod from a
separate eccentric by which the upper end of the link k is moved. The
slot of the link k is V shaped so that the block i has play at the
upper end of the slot. A short motion of the block i in the slot of the
link may be made to vary the cut off to any desired extent, and a
comparatively weak governor will control the expansion. r, r, are the
steam ports through which steam passes to the cylinder of the cut-off
pistons d, d, and s, 8, are the corresponding exhaust ports; t, t, are
packing rings placed on the cut-off valve pistons d, d, in such positions
that they pass over the steam ports u, u, in the bore of the cylinder x
before the said pistons d, d, reach the end of their stroke; v, v, are the
exhaust passages in the said cylinder x.
By an examination of the Drawing it will be seen that the effect of
this arrangement is that the steam port being small while the exhaust
port is large, the steam is "wire drawn" by the rapid motion of the
pistons d, d, so that the said pistons take only such a supply of steam
as is necessary to carry them over, and all further access of steam is
prevented by the packing ring or rings t, t, passing over the inlet port u
in the bore of the cylinder x; the steam employed for moving the cut off
valve is thus economized to the utmost extent. The closing of the
exhaust port v in the bore of the cylinder & imprisons a sufficiency of
steam to cushion the pistons d, d, and make them work noiselessly.
My Invention consists further of the following improvements in the
valves of direct acting steam pumping engines :-I construct the main
valve or valves and port faces which control the admission to and
emission of steam from the cylinder, with such a configuration of the
edges controlling the admission and emission of the steam that a reduc-
tion in the length of stroke of the valve or valves will reduce the area
available for the admission of steam, without affecting that for the
emission to a prejudicial extent.
I construct the subsidiary valve or valves, which control the admission
and emission of steam to the piston or pistons which move the main
valve or valves controlling the admission of steam to the cylinder and
the gear for moving the said subsidiary valve or valves, in such a

page_text: manner that while the main piston travels its normal stroke the main
valve travels its full stroke; but if the main piston travel beyond its
normal distance the travel of the main valve is reduced, and the area
available for the admission of steam is reduced also.
I construct the steam cylinder double, that is, with a smaller cylinder
within it, which smaller cylinder has a casing surrounding it forming
a steam jacket. There are two pistons, one annular with packings
working steam tight in the bore of the large cylinder, and outside the
casing of the smaller cylinder; the other piston works in the smaller
cylinder. The main valve or valves, while admitting steam to the front
end of the smaller cylinder, allow the steam from the back end to
exhaust into the front annular space of the larger cylinder, and on the
pistons making their stroke the steam is expanded to whatever extent
the annular area exceeds that of the smaller piston. Similarly for the
return stroke the steam is admitted to the back end of the smaller
cylinder, and the steam from the front end exhausts into the back
annular space. The steam from the annular space may exhaust into the
atmosphere or into a condenser, or otherwise.
I carry out these improvements in the following manner:-On the
steam cylinder I bolt the steam chest containing the main slide valve in
the usual way. The steam chest is bored out at each end to receive the
pistons which move the main valve. I cast these pistons in one piece,
and place the subsidiary valve that admits steam to them on the
connecting part of the casting. The subsidiary valve is held between
fixed guides, so that it cannot move with the said pistons, but can move
at right angles to their motion, and is moved by tappets or levers by the
main piston actuating a sliding piece and inclines on the back of the
subsidiary valve. The ports and passages for the admission and
exhaustion of steam from the said pistons are formed in their casting,
and I shape the edges and exhaust cavity of the said subsidiary valves
in such a manner that in normal working the steam in cut off and the
exhaust opened to the said pistons at such points in the stroke that the
main valve shall travel its normal stroke, but if the main piston travel
beyond its normal distance then the subsidiary valve will receive a
longer travel, and its edges and exhaust cavity will be so disposed that
the steam will be cut off earlier and the exhaust opened earlier to the
pistons which move the main slide valve, thus shortening its stroke.

page_text: on the rods, which latter is jointed to the connecting rod k', and the
latter to the lever k²; n, n, are the passages for the admission to and
exhaustion of steam from the pistons h, h (see Figures 7 and 9). In
Figures 6, 7, and 10, o is the exhaust cavity of the subsidiary valve i
which communicates by the passage p with the main exhaust q; r, r,
are openings through the subsidiary valve for admitting steam to the
pistons h, h. It will be understood that the greater travel the subsidiary
valve has over its valve face the earlier its edges 8, 8, will cut off the
steam supply, and the earlier the steam will exhaust from the pistons
h, h, through the configuration given to the openings r, r, and exhaust
cavity o; P is the pump, which may be of any desired construction ;
D is a distance piece also forming the bed plate. The ends of this bed
'plate are fixed, and the steam cylinders are bolted to it as shown, no
other bed plate being necessary; R, R, are the piston rods of the
annular piston d; R, s, is the piston rod of the smaller cylinder 6; C is
the cross head connecting the three piston rods; and R, p, is the piston
rod of the pump.
Having now described the nature of my Invention, and the manner
in which the same is to be performed, I wish it to be understood that I
do not limit myself to the precise details licrein described and illus-
trated, as the same may be varied without departing from the nature of
my Invention, but I claim as my Invention,-
First. The improvements in steam engines herein-before described and
illustrated in Figures 1, 2, 3, and 4 of the accompanying Drawings,
that is to say, the construction and arrangement or combination of the
parts of the cut-off valves or expansion gear of the said steam engines,
substantially as described and illustrated.
I claim with respect to the improvements in direct acting steam
pumping engines herein-before described and illustrated in Figures 5, 6,
7, 8, 9, 10, and 11 of the accompanying Drawings.
Secondly. Constructing direct acting steam pumping engines having
steam moved valves, with an inner cylinder and an outer annular
cylinder, substantially as and for the purpose described and illustrated.
Thirdly. The construction and combination of the pistons h, h, and
subsidiary valve i, the admission of steam to the said pistons being
effected by the said subsidiary valve moving transversely, substantially
as described and illustrated,

page_text: Fourthly. Forming the admission openings and exhaust cavity of the
subsidiary valve so that the longer its stroke the shorter will be that of
the main valve, as described and illustrated.
Fifthly. Forming the admission edges of the main valve so that the
shortening of its stroke rapidly affects the steam admission without
affecting the exhaust to the same extent, as described and illustrated.
Sixthly. Giving motion to the subsidiary valve by means of the
sliding piece marked 1, as described and illustrated.
Lastly. Constructing the distance piece of annular compound pump-
ing engines so as to form the bed plate, as described and illustrated.
'
•
In witness whereof, I, the said Henry Cherry, have hereunto set
my hand and seal, this Ninth day of May, in the year of our
Lord One thousand eight hundred and seventy-six.
Witness,
HENRY SKERRETT,
Clerk to George Shaw,
Birmingham.
HENRY CHERRY. (L.S.)