IMPROVEMENTS IN AUTOMATIC, VALVE AND PISTON COCKS
Year: 1884

page_text: I THOMAS SEAVILLE TRUSS of 17 Alkindon Road in the County of Middlesex
Professor of Natural Philosophy do hereby declare the nature of my Invention for
IMPROVEMENTS IN AUTOMATIC, VALVE AND PISTON COCKS, to be as follows:-
The first part of my said Improvements, consists in constructing a cylinder or
box, with an inlet pipe in one end that enters the cylinder for a given distance, in
a line with the longitudinal centre line of such cylinder: and near that end of the
cylinder through which such inlet pipe passes, an outlet pipe is attached, for the
discharge of the fluid transmited through such Valve and Piston Cock: but either
of these pipes may be used as the inlet or outlet pipes. The cylinder is constructed
with two areas for given distances therein, the least area commencing in a line
with the end of the inlet pipe that is within the cylinder, and the larger area
commencing where the smaller area ends and in this cylinder, which I name the
main cylinder, a piston is fitted to work in both of these areas at one time, and on
the end of this piston that has the least area, a valve which I name the discharge
valve, is fitted or formed therein, to act on the end of the inlet pipe within the
main cylinder, to close such inlet pipe. To the open end of the main cylinder a
cover is fitted, and on or in this cover, another cylinder or box is formed in which
another piston is fitted to work, this I name the regulating cylinder, and on or in
the outside of this regulating cylinder a plug cock is constructed and fitted to work,
this I name the governing cock, and in the socket of this governing cock are four
ports with connecting passages to the cylinders and the inlet and outlet pipes, and
two of such ports that are arranged in a diametrical centre line with each other.
give communication with the regulating cylinder through passages formed in the
side thereof, one to each end of such regulating cylinder, and of the other two ports
which are also arranged in a diametrical centre line with each other, one of such
ports gives communication by a passage constructed on the outside of the main
cylinder with the outlet pipe, and the other of such ports gives communication by
another passage formed in the side of the main cylinder with the larger area end of
such main cylinder at a point above the travel of the piston that works therein;
and from or about this point in the main cylinder, a passage is formed on the
outside thereof to a point in the inlet pipe outside of the main cylinder, and in this
passage a screw is fitted to work to close up or give a way through such passage,
and thereby regulate the quantity of fluid that shall pass into the larger area end
of the main cylinder, this screw I name the time screw. The ports in the socket
D
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page_text: of the governing cock are arranged at right angles to each other, and on a
diametrical centre line with each other, and that part of the plug of the governing
cock that rotates by such ports, is so formed as to have an aperture on each side,
and the ground in area part thereof to cover and close either two of the four ports,
when they are in a diametrical line taken through the centre of such plug and
ground in area, by it having sufficient ground in area on either side of its longi-
tudinal centre line, to so cover and close such two ports, when on the diametrical
centre line of either two of such ports.
By these contrivances any desired quantity of fluid is regulated to be transmited
through such Hydrostatic Automatic Valve and Piston Cocks, for each complete
motion of the plug of the governing cock, which is about one fourth of the circle
to release the fluid under pressure from the regulating cylinder, when the piston
therein is put in motion by the pressure of the fluid acting on the discharge valve,
and that then opens such discharge valve, and moves the piston to which it is
attached, thereby forceing the fluid that is in the larger area end of the main
cylinder, through the aperture in the plug of the governing cock, on to the piston
in the regulating cylinder, which piston then forces the fluid released from pressure
on the other side of such piston, through the other aperture in the plug of the
governing cock, and into the outlet pipe; after which the fluid entering the larger
area of the main cylinder by the time screw, closes the discharge valve, by reason
of the pressure of the fluid acting on the larger area of the piston to which such
discharge valve is attached, and overcoming the pressure on the discharge valve
which has a less area, and thus forceing such discharge valve to its seat on the end
of the inlet pipe to close the same, so that according to the distance the piston in
the regulating cylinder, and the piston with discharge valve attached, are regulated
to move, and the quantity of fluid allowed to pass into the main cylinder by the
'time screw in a given time, and the pressure exerted by or on the fluid, any given
quantity of fluid can be regulated, to be transmited through such Hydrostatic
Automatic Valve and Piston Cocks, for each complete motion of the plug of the
governing cock.
The seccond part of my said Improvements consist in a modification of the
arrangements herein before described, by substituting for the piston in the
regulating cylinder a division, to divide such regulating cylinder into two cylinders
or chambers. By this arrangement the fluid released therefrom by the governing
cock, is only forced from such cylinders or chambers by the air that may be
compressed therein, but flexible hollow vessels may be inserted therein, to be com-
pressed by the fluid entering such cylinders or chambers, to provide additional
force to discharge the fluid therefrom, when released by the governing cock; or
two pistons may be fitted to work in such cylinders or chambers, with springs or
other force to act on one side of each, to force the fluid from such cylinders or
chambers, when it is released by the governing cock.
The third part of my said Improvements consists of a further modification of
the arrangements herein before described, by substituting for the piston with the
discharge valve attached that works in the main cylinder, a piece of flexible
material, the outer area or part thereof being secured to the inside diameter of
such main cylinder by the cover, which flexible material is formed to act for and
instead of the piston, and also the discharge valve attached to it that works in the
main cylinder, as herein before described.
The fourth part of my said Improvements consists in a modification of the
arrangements herein before described, by substituting for the governing cock
herein before described, a governing rotary valve, constructed to work on a centre
pin, and in a chamber formed in or on the outside of the regulating cylinder, aud
in the area or seat on which such rotary valve works, there are four ports formed
therein at or about at right angles to each other, one of such ports giving
communication with the main cylinder, and two other of such ports giving com-
munication one to the top, and the other to the bottom of the regulating cylinder,
And the other port giving communication with the outlet pipe. In the face of

page_text: this rotary valve two recesses are formed, one on either side of a diametrical line
taken through the centre of the face of such valve, and the solid centre part thus
formed as a given area from such diametrical centre line, which area on the face of
such rotary valve, covers and closes any two of the four ports in the seat of such
rotary valve that are in a diametrical centre line with each other when passing
over the same, and when the port giving communication with the main cylinder is
omited from such valve seat, and the passage therefrom is conducted into the
chamber in which such rotary valve works, the fluid acting on such rotary valve
keeps it to its seat; then there are only three ports in the seat on which such
rotary valve works, but a passage is made through the rotary valve into one of the
recesses, formed in the face thereof for the fluid to pass through and give communi-
cation with the ports in the seat of such rotary valve.
The fifth part of my said Improvements consists in a modification of the
arrangements herein before described, by substituting for the governing cock herein
before described, a governing slide valve set to reciprocate a given distance. The
seat of this valve is constructed with three ports, the centre one giving communi-
cation with the outlet pipe, and each of the other two ports giving communication
one to the top, and the other to the bottom of the regulating cylinder, and the
passage from the main cylinder is conducted into the chamber in which such slide
valve works, for the fluid to pass through and give communication with the ports
in the seat of such slide valve; and in the face of this slide valve a recess is formed
for a given depth, and with an area equel to the area of any two of the ports in the
seat of such slide valve and the division between them, and the total area of the
face of the valve is a little larger than the area of the three ports and their
divisions in such valve seat, in order to cover and close them when passing over
them.
The effect of the modifications as herein before described in the fourth, and fifth
parts of my said Improvements, are the same as that obtained by the governing
cock herein before first described.
The several parts of my said Improvements are held together by screws, screw
bolts, or any of the contrivances usual for such purposes, and the ends of the plugs
of the governing cocks, or the ends of the spindles of the governing valves, that
project from their sockets or chambers, may be worked or noved by knobs, levers,
or any other suitable contrivance attached thereto, to give transmission of fluid
through such Hydrostatic Automatic Valve and Piston Cocks.
As my said Improvements are capable of various modifications without departing
from the principle thereof, I do not restrict myself to material, dimensions, or the
precise form or placement of the several parts thereof, or to the packing material to
be used in connection with the pistons, spindles, or valves, of such Hydrostatic
Automatic Valve and Piston Cocks.
In order that the nature of my said improvements and in what manner the same
are to be performed, may be more fully understood, I will proceed to describe the
Beveral Figures on the sheet of Drawing hereunto annexed, all of which Figures
are marked with the like letters of reference, to the like parts throughout.
Figure 1, is a longitudinal view part in section, of an Automatic Valve and Piston
Cock, constructed according to the first part of my said improvements as herein
before described; and Figure 2, is a side view of Figure 1, with a cross section
taken at the line A, A, in Figure 1, to show the passages to and from the governing
cock, and the form of the plug of the governing cock at the part in connection with
such passages. B, is the main cylinder and C, the piston with the discharge valve a,
attached to the least area end thereof, which discharge valve acts on the end of the
inlet pipe D. E, is the outlet pipe; F, is the main cylinder cover with the regulating
cylinder G, formed thereon; and b, is the piston that works therein, having the
spindle c, that works in the socket d. c, is the plug of the governing cock; and f,
is the passage from the main cylinder B: and y, the passage to the outlet pipe E:
and h, the passage to the top of the regulating cylinder G: and i, is the passage to
the bottom of the same; j.j. are the apertures in the plug e, that forms two passages

page_text: by such plug: k, is the time screw in the passage 1, formed on the outside of the
main cylinder B: and m, is the time hole: and n, is a spring to counterbalance the
friction on the piston C, and secure a preponderance of pressure thereon to close
the discharge valve a; b¹, is a cap on the regulating cylinder G: and c¹, is n screw
to regulate the travil of the piston b: and el, is a lever to work the plug cock e,
with. Figure 3, is a longitudinal view part in section, of a modification of the
arrangements herein before last described, and consists, in constructing the main
cylinder with one arc only. Figure 4, is a longitudinal view part in section, of a
modification of the arrangements herein before described, and consists, in con-
structing the main cylinder with one area only, and the division o, in it, and with
the inlet pipe D, entering the side of the main cylinder B; and the outlet pipe E,
in a line with the longitudinal centre line thereof for the discharge valve a, to act
on the valve seat p, constructed within the outlet pipe E, the piston C, and discharge
valve a, being connected together by the spindle q. In this arrangement the fluid
under pressure acts on the underside of the piston C, to close the discharge valve a.
Figure 5, is a modification of the arrangements herein before described, showing one
form of a cross section of the regulating cylinder G, when such cylinder is divided
into two chambers, according to the seccond part of my said improvements as
herein before described; r, is the division: and 8, and t, the two chambers.
Figure 6, is a longitudinal section of the plug of the governing cock employed
when the regulating cylinder is divided into two chambers, in this case the fluid
under pressure from the main cylinder passes through the passage a', in the centre
of the plug e, to the aperture j, therein, from the passage f, from the main
cylinder B. Figure 7, is a longitudinal view, part in section, of the arrangements
herein before described in the Third part of my said improvements; in which u, is
the flexiable material, substituted for the piston described in the first part of my
said improvements, and that acts for the piston and discharge valve therein
described; v, v, are check plates: w, is the flexiable material substituted for the
piston in the regulating cylinder G. Figure 8, is a plan of the seat for a rotary
valve, constructed according to the Fourth part of my said improvements; in which
H, is the valve seat: and f, g, h, i, are the four ports communicating with the
passages marked with the like letters of reference: and Figure 9, is a plan of the
face of the rotary valve, that works on the rotary valve seat H; and L, is the
rotary valve that works on the same; and x, a, are the apertures in the face of
such rotary valve that form two chambers therein, to act as passages for the fluid
from port to port. Figure 10 is a section of a slide valve and seat with ports and
passages, constructed according to the Fifth part of my said improvements: in
which y, is the slide valve and d', the aperture or chamber formed therein:
and 2, the seat on which such slide valve works: and f, g, h, i, the passages in
connection with such slide valve: and N, is the valve cover: and f¹, the
valve rod.
:

page_text: CUTLEIE
OPECIFICATION.
I THOMAS SEAVILLE TRUSS of 10, Strathblaine Road St John's Hill London in
the County of Surrey Professor of Natural Philosophy do hereby declare the
nature of my Invention for IMPROVEMENTS IN AUTOMATIC VALVE AND PISTON
Cocks and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
My said Improvements consist of the construction of Automatic Valve and
Piston Cocks for governing the transmission of fluids, and constitute water waste
preventing Valve Cocks, applicable for water closets, urinals, and other purposes.
The First part of my said Improvements consist of constructing a cylinder or
box with an inlet pipe in one end that enters the cylinder for a given distance in
a line with the longitudinal centre line of such cylinder, and near that end of the
cylinder through which such inlet pipe passes an outlet pipe is attached for the
discharge of the fluid transmited through such Valve and Piston Cock, but either
of these pipes may be used as the inlet or outlet pipe. The cylinder may be
constructed with one area or diameter only, but by preference with two areas or
diameters for a given distance therein, the least area commencing in a line with
the end of the inlet pipe that is within the cylinder, and the larger area com-
mencing where the smaller area ends, and in this cylinder which I name the main
cylinder a piston is fitted to work in both of these areas at one time, and on the
end of this piston that has the least area a valve which I name the discharge
valve is fitted or formed therein or thereon to act on the end of the inlet pipe
within the main cylinder to close such inlet pipe. To the open end of the main
cylinder a cover is fitted, and on or in this cover another caped cylinder or box is
formed in which another piston is fitted to work this I name the regulating
cylinder, and on or in the outside of this regulating cylinder at a given part thereof
a plug cock is constructed and fitted to work this I name the governing cock, and
in the socket of this governing cock are four ports with connecting passages to the
main and regulating cylinders and the outlet pipe, and two of such ports that are
arranged in a diametrical centre line with each other give communication with the
regulating cylinder through passages formed in the side thereof one to cach end of
such regulating cylinder, and of the other two ports which are also arranged in a
diametrical centre line with each other one of such ports gives communication by a
passage constructed on the outside of the main cylinder with the outlet pipe, and
the other of such ports gives communication by another passage formed in the side
of the main cylinder with the larger area end or top of such main cylinder at a
point above the travel of the piston that works therein, and from or about this
point in the main cylinder a passage is formed on the outside thereof to a point in
the inlet pipe outside of the main cylinder, and from this passage a hole which
I name the time hole is made into the main cylinder, and in this hole a screw
which I name the time screw is fitted to work to close up or give a way for the
fluid to pass through such time hole, and thereby regulate the quantity of fluid
that shall pass into the larger area end of the main cylinder in a given time. The

page_text: ports in the socket of the governing cock are arranged at right angles to each other
and on a diametrical centre line with each other, and that part of the plug of the
governing cock that rotates by such ports is so formed as to have an aperture on
each side to form two passages by such plug, but leaving sufficient of the ground in
area part thereof to cover and close either two of the four ports that are arranged
in a diametrical line taken through the centre of such plug and ground in area, by
reason of the sufficient ground in area part left on each side of its longitudinal
centre line to so cover and close either two of such four ports when such ground in
area parts of such plug are on the diametrical centre line of either two of such
four ports.
By these arrangements any desired quantity of fluid is regulated to be transmited
through such Automatic Valve and Piston Cocks for each complete opening motion
of the plug of the governing cock, which is about the one fourth part of the circle
of rotation to release the fluid under pressure from the regulating cylinder, when
the piston therein is put in motion by the pressure of the fluid acting on the
discharge valve, and that then opens such discharge valve by forceing it from its
seat, and so moves the piston to which it is attached, thereby forceing the fluid that
is in the larger area end of the main cylinder through one of the apertures in the
plug of the governing cock on to the piston in the regulating cylinder, which
piston then force's the fluid released from pressure on the other side of such piston
through the other aperture in the plug of the governing cock into the outlet pipe,
and after the discharge of this released fluid the fluid entering the larger area end
of the main cylinder by the time hole closes the discharge valve, by reason of the
pressure of the fluid acting on the piston to which such discharge valve is attached
over-coming the pressure on the discharge valve from the fluid in the inlet pipe as
the discharge valve has a less area, and thus forceing such discharge valve to its seat
on the end of the inlet pipe to close the same; so that according to the distance the
piston in the regulating cylinder and the piston with the discharge valve attached
are regulated to move or travel, and the quantity of fluid allowed to pass into the
main cylinder by the time hole in a given time and the pressure exerted by or on
the fluid, any given quantity of fluid is regulated to be transmited through such
Automatic Valve and Piston Cocks.
The Seccond part of my said Improvements consist of a modification of the
arrangements herein before described, by constructing in the regulating cylinder a
division to divide such regulating cylinder into two cylinders or chambers. By
these arrangements the fluid released from either of these cylinders or chambers by
the governing cock is only forced from such cylinders or chambers by the air that
may be compressed therein, but flexible hollow vessels may be inserted therein to
be compressed by the fluid entering such cylinders or chambers to provide additional
force to discharge the fluid therefrom when such fluid is released from pressure by
the governing cock, or two pistons may be fitted to work in such cylinders or
chambers with springs or other force to act on one side of each to force the fluid
from such cylinders or chambers when the fluid is released from pressure by the
governing cock. In these arrangements the fluid from the main cylinder may pass
through a hole or passage in the centre of the plug of the governing cock from the
end of the ground in area part thereof into one of the apertures in the side of such
plug in this case there will only be three ports or passages in the socket in which
the plug works, one of such ports having communication with the outlet pipe, and
each of the other two ports giving communication with either of the regulating
cylinders or chambers so formed as described.
The Third part of my said Improvements consist of a modification of the
arrangements herein before described, by substituting for the piston with discharge
valve attached in the main cylinder as also for the piston in the regulating cylinder
herein before first described piceses of flexible material, the outer areas or parts
thereof being secured to the inside diameters of such cylinders by their covers,
which flexible material is formed to act for and instead of the piston and discharge
valve in the main cylinder, and as and for the piston in the regulating cylinder.

page_text: The Fourth part of my said Improvements consist of a modification of the
arrangements herein before described, by substituting for the governing cock
before described, a governing rotary valve constructed to work on a centre pin and
in a chamber formed in or on the outside of the regulating cylinder, and in the area
or seat on which such rotary valve works there are four ports formed therein at or
about at right angles to each other on two diametrical centre lines, one of such parts
giving communication with the main cylinder, and two of such ports giving
communication one to the top and the other to the bottom of the regulating
cylinder, and the other of such four ports giving communication with the outlet
pipe. In the face of this rotary governing valve two recesses are formed for the
fluid to pass through, one on each side of a diametrical line taken through the
centre of the face of such valve, and the solid centre part thus formed has a given
area from such diametrical centre line, which area on the face of such rotary valve
covers and closes any two of the four ports in the seat of such rotary valve that are
in a diametrical centre line with each other when passing over the same, and when
the port giving communication with the main cylinder is omitted from such rotary
valve seat and the passage from the main cylinder is conducted into the chamber
in which such rotary valve works, then the fluid acts on the top of such rotary
valve to keep it to its seat; in this case there are only three ports in the set on
which such rotary valve works, but a passage is made through the rotary valve
into one of the recesses formed in the face thereof for the fluid from the main
cylinder to pass through and give communication with the ports in the seat of such
rotary governing valve.
The Fifth part of my said Improvements consist of a modification of the
arrangements before described, by substituting for the governing cock and governing
rotary before described, a governing slided valve set to reciprocate a given distance
in a chamber constructed in or on the outside of the regulating cylinder. The seat
of this valve is constructed with three ports in it, the centre port giving communi-
cation with the outlet pipe, and each of the other two ports giving communication
one to the top and the other to the bottom of the regulating cylinder, and the
passage from the main cylinder is conducted into the chamber in which such slide
valve works for the fluid to pass through and give communication with the ports in
the seat of such slide valve, and in the face of this valve a recess is formed to give
a passage for the fluid from port to port of a given depth, breadth and width, with
an area equal to the area of any two of the ports in the seat of such slide valve
and the division between them, and the total area of the face of such slide valve is
a little larger than the area of the three ports and their divisions in the seat of
such governing slide valve, in order to cover and cluse all the ports when passing
over them.
Where required springs are employed to act against the pistons within the
cylinders to over-come the friction of the working parts, and secure a preponderance
of pressure on the piston to close the discharge valves attached to them."
The several parts of my said Improvements are held together by screws, screw
bolts, or any of the contrivances usual for such purposes, and those ends of the plugs
of the governing cocks or spindles of the rotary governing valves or slide valves
that protrude outside of the chambers in which they work, may have knobs, levers,
or any other suitable contrivance attached thereto to give notion to the same.
In order that the nature of my said Improvements and in what manner the same
are to be performed may be more fully understood, I will proceed to describe the
several Figures on the Sheet of Drawing hereunto annexed, all of which Figures
are marked with the like letters of reference to the like parts throughout.
Figure 1 is a longitudinal view part in section of an Automatic Valve and Piston
Cock constructed according to the first part of my said Improvements as herein
before described, and Figure 2 is a side view of Figure 1 with a cross section taken
at the dotted line A A to show the passages to and from the governing cock, and
the form of the plug of the governing cock at the part in connection with such
passages. B is the main cylinder, and C the piston with the discharge valve a
**

page_text: attached to the least area end thereof, which discharge valve acts on the end of the
inlet pipe D, and E is the outlet pipe, and F is the main cylinder cover with the
regulating cylinder G formed thereon, and bis the piston that works therein having
the spindle c attached to it which works in the socket d, and e is the plug of the
governing cock working in the socket h¹, and f is the passage from the main
cylinder B, and g is the passage to the outlet pipe E, and h is the passage to the
top of the regulating cylinder G, and i is the passage to the bottom of such regu-
lating cylinder, and jj are the apertures in the plug e that forms two passages by
such plug; k is the time screw in the passage formed on the outside of the main
cylinder B, and m is the time hole, and n is a spring to counterbalance the friction
on the piston C to secure a preponderance of pressure thereon to close the discharge
valve a, and o is the cap on the regulating cylinder G and p is a set screw to
regulate the travel of the piston b, and q is a lever attached to the plug e of the
governing cock to give motion to the same with.
Figure 3 is a cross section of the regulating cylinder taken at a point clear of the
governing cock when such regulating cylinder is divided into chambers according
to the modification described in the seccond part of my said Improvements, in which
t is the division and u and r are the two chambers; and Figure 4 is a longitudinal
section of the plug of the governing cock constructed according to the modification
also described in the seccond part of my said Improvements, in which w is the
passage through such plug.
Figure 5 is a longitudinal section of the arrangements according to the modifi-
cation described in the third part of my said Improvements, in which x is the
flexible material in the main cylinder B to act for and instead of the piston C and
discharge valve a, and y y are check plates to give stibility to the flexible material x,
and is the flexible material in the regulating cylinder G to act for and instead of
the piston b with the spindle c.
2
Figure 6 is a plan of the seat for the rotary governing valve, and Figure 7 is a
plan of the face of the governing rotary valve to work on such seat constructed
according to the modification described in the fourth part of my said Improvements,
in which H is the valve seat and f g h i are the ports having communication with
the passages with like letters of reference, and a is the pin on which the valve
rotates; and 1 is the rotary valve and b¹ b¹ are the recesses in the face of such
valve that form two passages therein, and i¹ is the solid centre part on the face of
such valve.
Figure 8 is a longitudinal section of the slide valve constructed according to
the modification described in the fifth part of my said Improvements, in which J is
the governing slide valve seat and ghi are the ports in the same communicating
with the passages having the like letters of reference, and K is the valve cover,
and c is the governing slide valve having the recess d' therein, and e¹ is the valve
rod for giving motion to the same.
As my said Improvements are capable of various modifications without departing
from the principle thereof I do not restrict myself to material, dimensions, or the
precise form or placement of the several parts thereof, or to the conducting of the
fluid discharged from the regulating cylinder into the outlet pipe as it may be
discharged at any point after it as passed the governing cock, rotary valve or slide
valve; or to the packing material to be employed in connection with the pistons,
spindles or valves in such Automatic Valve and Piston Cocks.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
1st The construction of Automatic Valve and Piston Cocks for the transmission
of fluids that have a main cylinder with an inlet and an outlet pipe attached
thereto, and a detached piston working in such cylinder to which piston a discharge
valve is fitted or formed therein or thereon to act on the end of the inlet pipe, and
having a regulating cylinder with a piston working therein conjunctive with such

page_text: main cylinder, with a governing plug cock, rotary valve, or slide valve intervening
between the passages to and from such cylinders and the outlet pipe, and having a
time hole into the main cylinder from the inlet pipe, substantially as and for the
purpose hereinbefore set forth.
2d The dividing of the regulating cylinder into two cylinders by a partition with
a piston to work in each part thereof; or dividing such regulating cylinder by a
partition into two chambers without pistons, substantially as and for the purpose
herein before set forth.
3d The arrangement of the flexible material to act for and instead of the piston
and discharge valve in the main cylinder, and also to act for and instead of the
piston in the regulating cylinder, with the governing plug cock, rotary valve, or
slide valve intervening between the passages to and from such cylinders and the
outlet pipe, substantially as and for the purpose hereinbefore set forth.