IMPROVEMENTS IN STEAM PUMPING OB BLOWING ENGINES
Year: 1870

page_text: '
LETTERS PATENT to Martin Benson, of 9, Southampton Buildings,
London, Engineer, for the Invention of "IMPROVEMENTS IN STEAM
PUMPING OB BLOWING ENGINES."-A communication from abroad by
James Riley Maxwell and Ezra Cope, both of Cincinnati, Ohio,
United States of North America.
Sealed the 14th October 1870, and dated the 17th May 1870.
PROVISIONAL SPECIFICATION left by the said Martin Benson at the
Office of the Commissioners of Patents, with his Petition, on the
17th May 1870.
I, MARTIN BENSON, of 9, Southampton Buildings, London, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN STEAM PUMPING OR BLOWING ENGINES," a communication, to be as
follows
:-
::
The engines to which my improvements are applicable are those for
obtaining a reciprocating motion for any purpose, more particularly for
working -pumps. and blowing engines requiring -a-reciprocating motion;"
where the piston of the steam engine, pump, or blowing cylinders are

page_text: worked by motion taken from the piston or piston rod of the engine,
without the aid of an eccentric and its accompanying rods as usually
employed.
A part of the improvement consists in the application and arrangement
of the parts employed for moving the main slide valve or valves of the
engine with the least possible friction of such parts, so as to cause a
certain or positive motion of the valves at all times, either when the
piston is working at slow or quick speeds or in changing the direction of
its stroke under any pressure of steam that may be employed for working
the engine. For this object the valve face of the main engine is provided
with a supplementary steam cylinder, piston, and valve enclosed in the
valve box for working the main valve of the engine. This cylinder may
be made separate and attached by means of screw bolts, or if desired it
may be cast on the main valve seat. The valve of the supplementary
cylinder may be employed for exhausting the steam from its cylinder
only, or for both exhausting and admitting it as may be desired, but in
either case provision is made for retaining sufficient steam in the ends of
the supplementary cylinder as a cushion, so as to prevent its piston from
striking. The piston of this cylinder is provided with piston rods or ends
cast on or otherwise attached to each end of the piston and the cylinder;
its piston and rods are provided with a system of steam ports and
passages for admitting steam to and from the cylinder for working its
piston. The rods or ends of the supplementary piston are arranged
with the main valve or valves of the engine so that the working of the
piston gives the valves the required motion for admitting steam to
and from the main cylinder and for permitting the wearing of each
spart without causing any friction from the unequal wearing of the valves
compared with the parts that move them. The ends of the piston where
they come in contact with the valves for moving them are themselves
made to form valves for admitting steam to the supplementary cylinder
through its piston ends, which are made hollow with openings so formed
as to admit steam into the cylinder when its piston may happen to
be in contact with the ends of the supplementary cylinder. The valve
of the supplementary cylinder for admitting steam to or from it for
moving its piston is worked by the motion of a partially rotating shaft
enclosed in the valve box, which is furnished with a lever or rod for
taking hold of and moving the valve; this shaft receives its motion

page_text: from the main piston of the engine by means of arms or levers firmly
attached to its ends and extending into the ends of the cylinder through
openings made for the purpose, so that the piston as it terminates its
stroke at either end of the cylinder comes in contact with one of the
5 levers and thereby moves or oscillates the shaft in opposite directions
for giving the required motion to the valve through the medium of the
parts before described..
If desired another method of moving the valve of the supplementary
cylinder may be effected by rods or tappets extending through the
cylinder heads a short distance into the cylinder, their outer ends being
connected with the valve through a system of levers and rods made to
suit the relative position of the valve, and as the piston terminates its
stroke at each end of the cylinder it is made to move these tappets,
thereby giving the required motion to the valve; or the cylinder ends of
the engine and pump can be set sufficient distance apart, so that the
piston rod between the cylinders may be furnished with an arm or cross-
head for moving a rod to which the valve of the supplementary cylinder
is attached, thereby moving the valve. This arrangement of valves can
be constructed and' applied to vertical or horizontal cylinders, so that
different pressures of steam may be admitted and used in both ends of
the cylinder at the same time, or the steam may be entirely shut off from
one end of the cylinder, and its full pressure admitted into the other.
This is done by dividing or making two separate valve boxes, one at or
for each end of the cylinder. One of these boxes will contain a valvė
for admitting steam to and from one end of the main cylinder; also the
supplementary cylinder and its appendages for moving the valves, while
the other box contains a valve for admitting steam to and from the
opposite end of the cylinder; each of the valve boxes is furnished with
an independent steam pipe and valve for regulating the pressure of
steam. A stem passes through a partition separating the valve boxes,
which is provided with means for making it steam-tight. One end of
this stem is attached or arranged to one end of the piston of the sup-
plementary cylinder, and the other end to one of the main valves of
the engine, while the other main valve of the engine is attached or
arranged to the opposite end of the supplementary piston, and enclosed
in the valve box containing the supplementary cylinder: By this
arrangement both the slide valves of the engine are in separate chambers
or valve boxes, and are moved at the same time by the piston of the
supplementary cylinder, or, if desired, the supplementary cylinder-and its

page_text: appendages may be placed in a separate case entirely independent of
the valve boxes.
This valve arrangement is more particularly applicable to vertical
pumping engines when little or no pressure of steam is required for the
down stroke when working single-acting pumps, the weight of the piston
rods and their appendages being sufficient to move the piston in its
downward stroke.
Another method of accomplishing this object is, instead of using two
independent valves, to use a single slide valve, and provide the steam
passage or passages leading from the slide valve into the ond or ends of
the cylinder with a throttling valve or valves, and so constructed that
the steam as it is admitted by the slide valve into the cylinder can be
throttled in its passage to obtain the required pressure in the cylinder.
In the mean time the throttling valve or valves are made to open equal
to the full area of the steam passage in which they are placed so as to
permit a free escape of steam from the cylinder to prevent back
pressure.
0
These throttling valves can be constructed in various forms for arrange-
ment in the steam passages of the cylinders. The form preferred is a
hinge valve attached to and adjusted by a screw stem, so that if
required the passage may be closed nearly tight against the flow of
steam into the cylinder for regulating its pressure therein, and at the
same time made open equal to the full area of the steam passage in
which it is placed for permitting the free escape of the steam from the
cylinder after performing its work, or an ordinary conical valve may be
used, and so arranged in the steam passage and to its regulating stem
that the flow of steam into the cylinder can be adjusted to any required
pressure, and at the same time the valve is left free to move or rise on
its stem to permit a free escape of steam from the cylinder.
The valve box is provided with a stem and lever on its inner end,
which lever is arranged with the valve or valves, and a starting bar is
attached to the outer end of this stem for moving the valve or valves
by hand if required in starting the engine. The boss of this starting
lever is so constructed as to serve as a stuffing gland around the stem
where it enters the valve box. This is effected by attaching the boss
of the starting bar to the stem by a key or feathers sufficiently loose to
permit it freely moving longitudinally on the stem, but not to rotate
without moving the stem at the same time. The outer end of the stem

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Martín Benson in the Great Seal Patent Office
on the 5th November 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MARTIN
BENSON, of 9, Southampton Buildings, London, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of May, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Martin Benson, Her special licence
that I, the said Martin Benson, my executors, administrators,. and
assigns, or such others as I, the said Martin Benson, 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 PUMPING OR BLOWING ENGINES," a communication to me from abroad
by James Riley Maxwell and Ezra Cope, both of Cincinnati, Ohio,
United States of North America, upon the condition (amongst others)
that I, the said Martin Benson 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 Martin Benson 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:—
The engines to which my improvements are applicable are those for

page_text: for working pumps and blowing engines requiring a reciprocating
motion, where the piston of the steam engine, pump, or blowing
cylinders are attached to the same piston, and the steam valve of the
engine worked by motion taken from the piston of the engine without
the aid of an eccentric and its accompanying rods as usually employed. 5
A part of the improvement consists in the application and arrange-
ment of the parts employed for moving the main slide valve or valves
of the engine with the least possible friction of such parts, so as to
cause a certain or positive motion of the valves at all times, either when
the piston is working at slow or quick speeds or in changing the direc- 1
tion of its stroke under any pressure of steam that may be employed
for working the engine. For this object the valve face of the main
engine is provided with a supplementary steam cylinder, piston, and
valve enclosed in the valve box for working the main valve of the
engine. This cylinder may be made separate and attached by means 1
of screw bolts, or if desired it may be cast on the main valve seat. The
valve of the supplementary cylinder may be employed for exhausting
the steam from its cylinder only, or for both exhausting and admitting
it as may be desired, but in either case provision is made for retaining
sufficient steam in the ends of the supplementary cylinder as a cushion
so as to prevent its piston from striking. The piston of this cylinder
is provided with piston rods or ends cast or otherwise attached to cach
end of the piston and the cylinder, its piston and rods are provided
with a system of steam ports and passages for admitting steam to and
from the cylinder for working its piston. The rods or ends of the
supplementary piston are arranged with the main valve or valves of
the engine, so that the working of the piston gives the valves the
required motion for admitting steam to and from the main cylinder,
and for permitting the wearing of each part without causing any
friction from the unequal wearing of the valves compared with the
parts that move them. The ends of the piston where they come in
contact with the valves for moving them, are themselves made to form
valves for admitting steam to the supplementary cylinder through its
piston ends, which are made hollow with openings so formed as to admit
steam into the cylinder, when its piston may happen to be in contact
with the ends of the supplementary cylinder. The valve of the supple-
mentary cylinder for admitting steam to or from it, for moving its
piston is worked by the motion of a partially rotating shaft enclosed

page_text: .
in the valve box, which is furnished with a lever or rod for taking hold
of and moving the valve. This shaft receives its motion from the main
piston of the engine, by means of arms or levers firmly attached to
its ends and extending into the ends of the cylinder. 'through openings
made for the purpose, so that the piston as it terminates its stroke at
either end of the cylinder comes in contact with one of the levers, and
thereby moves or oscillates the shaft in opposite directions for giving
the required motion to the valve through the medium of the parts
before described
-
If desired another method of moving the valve of the supplementary
cylinder may be effected by rods or tappets extending through the cylinder
heads a short distance into the cylinder, with their outer ends being
connected with the valve through a system of levers and rods, made to
suit the relative position of the valve, and as the piston terminates its
stroke at each end of the cylinder it is made to move these tappets,
thereby giving the required motion to the valve or the cylinder of the
engine; and pumps can be set sufficient distance apart, so that the piston
rod between the cylinders may be furnished with an arm or crosshead
for moving a rod to which the valve of the supplementary cylinder is
attached, thereby moving the valve..
This arrangement of valve can be constructed and applied to vertical
or horizontal cylinders, so that different pressures of steam may be
admitted and used in both ends of the cylinder at the same time, or
the steam may be entirely shut off from one end of the cylinder and
its full pressure admitted into the other. This is done by dividing or
making two separate valve boxes, one at or for each end of the cylinder,
one of these boxes will contain a valve for admitting steam to and from
one end of the main cylinder, also the supplementary cylinder and its
appendages for moving the valves, while the other box contains a valve
for admitting steam to and from the opposite end of the cylinder; each
of these valve boxes is furnished with an independent steam pipe and
valve for regulating the pressure of steam. A stem passes through
the partition separating the valve boxes, which is provided with means
for making it steam-tight'; one end of this 'stem is attached or arranged
to one end of the piston of the supplementary cylinder, and the other
end to one of the main valves of the engine, while the other main
valve of the engine is attached or arranged to the opposite end of the
supplementary piston and enclosed in the valve box containing the sup.
3.
'

page_text: plementary cylinder. By this arrangement both the slide valves of the
engine are in separate chambers or valve boxes, and are moved at the
same time by the piston of the supplementary cylinder, or if desired
the supplementary cylinder and its appendages may be placed in a
separate case entirely independent of the valve boxes.
This valve arrangement is more particularly applicable to vertical
pumping engines when little or no pressure of steam is required for the
down stroke when working single acting pumps, the weight of the
piston rods and its appendages being sufficient to move the piston in its
downward stroke.
Another method of accomplishing this object, is, instead of using two
independent valves by using a single slide valve, and providing the
steam passage or passages leading from the slide valve into the end or
ends of the cylinder with a throttling valve or valves, and so constructed
that the steam as it is admitted by the slide valve into the cylinder, can
be throttled in its passage to obtain the required pressure in the cylinder.
In the meantime the throttling valve or valves are mode to open cqual
to the full area of the steam passage in which they are placed, so as to
permit a free escape of the steam from the cylinder to prevent back
pressure. These throttling valves can be constructed in various forms
for arranging in the steam passages of the cylinders. The form preferred
is a hinge valve attached to and adjusted by a screw stem, so that if
required it may be closed nearly tight against the flow of steam into the
cylinder for regulating its pressure therein, and at the same time made
to open equal to the full area of the steam passage in which it is placed,
for permitting the free escape of the steam from the cylinder after
performing its work; or an ordinary conical valve may be used, and so
arranged in the steam passage and to its regulating stem, that the flow
of steam into the cylinder can be adjusted to any required pressure, and
at the same time the valve is left to move or rise on its stem to permit
a free escape of steam from the cylinder. The valve box is provided
with a stem and lever on its inner end, which lever is arranged with the
valve or valves, and a starting bar is attached to the outer cud of this
stem for moving the valve or valves by hand if required in starting the
engine.
In order to give a fuller understanding of the said Invention, I will
now refer to the accompanying Drawings hereunto annexed, forming
part of this Specification by the letters and figures of reference marked

page_text: thereon; similar letters of reference refer to corresponding parts on cachi
Sheet of Drawings.
Figure 1, Sheet 1, is a longitudinal sectional view of a cylinder, with
the improved valve arrangement attached thereto; Figuro 2 is a
transverse sectional view of the cylinder and valve arrangement through
their centres; Figure 3 is a top view of the main valve seat; Figure 4
is a sectional view of a valve arrangement for varying and regulating
the working pressure of steam in or both ends of the cylinder; Figures 5
and 6 represent different views of the engine applied for working
pumps.
A is a cylinder, provided with any suitable constructed piston a, and
furnished with a piston rod f, working through an ordinary stuffing box;
B, B, is the valve box; C, C, is a double slide valve, that is, a valve
for each end of the cylinder, but joined or cast together by rib pieces c², c',
as represented in the different Figures. The cylinder is furnished with
steam passages as usual; G is the inlet passage to the valve box; and
I the exhaust or outlet passage; P, P', are steam passages leading to
and from the ends of the cylinder and valve box; D is a supplementary
steam cylinder attached to the valve seat of the main cylinder by means
of scrow bolts, as represented in Figure 2. This cylinder in the present
arrangement is placed between the two main slide valves C, C, and is
provided with a piston E, to which are cast or attached hollow piston
rods g', g, working through the ends of the supplementary cylinder, as
represented in Figure 1. The duty of this piston is to work or move
the main slide valve C, C, by the ends of the rods g³, 9, forcing against
the flanges F, F, cast or attached to the valve.C, C. The steam for
working the piston E is admitted into the cylinder through passages in
the centre of the piston ends or rods g', g, which are made to serve as
valves and passages i, i, the latter passage being made at the angles
where the piston ends or rods g', g, join the piston E, as represented
in Figure 1. The steam is discharged or escapes from the supplementary
cylinder by the valve H; this valve is worked by the piston a alternately
striking or pressing against the arms M, M, in an oblique manner.
These arms are attached to the shaft L and project through openings
into the ends of the cylinder, and by the piston a moving the arms the
shaft is made to turn or oscillate alternately in opposite directions, and
move the valve H by the lever N which is attached to the shaft L, L.
The supplementary cylinder is furnished with steam- passages- h, h',

page_text: and J, J', for the escape of steam therefrom by the valve I; the ports
of these passages in the cylinder are made a short distance from the ends
of the cylinder, as represented in Figure 1, in order to cushion the steam
to prevent the piston E from striking the ends of the cylinder.
The working of the valve is effected in the following manner :-The
piston a in its present position is represented moving in the direction of
the dart marked on the piston rod f; when the piston arrives near the
end of the cylinder it strikes or presses the arm or lever M up or down,
as the case may be, and moves the valve H through the medium of the
shaft L and arm N as before described, and permits the steam to escape
from the supplementary cylinder through the steam passage and J into
the steam passage P' at the right-hand end of the cylinder. The exhaust
stcam passage from the X end of the supplementary cylinder are fully
shown in Figure 2. When the steam is thus liberated from the supple-
mentary cylinder the piston end.g presses against the flange F cast or
attached to the valve C, C. In the meantime steam passes into the
opposite end of the supplementary cylinder through the steam passage
in the piston rod 7 and openings i and move the piston E to the opposito
or X end of the cylinder, and with it carries or moves the main valve
C, C. By thus admitting steam to the supplementary cylinder the ends
of the rods g¹, g, are made to perform the function of valves. For this
object sufficient space or play is left between the ends of the rods g¹, g,
and flanges F, F, for the passage of steam into and through the piston
rod, as represented at the g¹ end of the piston by the darts. The steam is
made to escape from the supplementary cylinder into the exhausting
end of the main cylinder just before the piston of the main cylinder
terminates its stroke, so that the exhaust end of the supplementary
cylinder is only in communication with the exhaust end of the main
cylinder during the space of time required for moving the main valve C, C,
by the piston of the supplementary cylinder, and directly after the valves ;
move, the exhaust end of the supplementary cylinder is brought in
communication with the steam end of the main cylinder A by the arrange-
ment of the steam passage h, J, or ', J', leading from the supplementary
cylinder into the steam passages P, P', of the main cylinder. For
instance, the piston rod of the main cylinder is supposed to be moving a
in the direction of the dart as before stated, which makes the right-hand
end of the main cylinder at present as denoted by the position of the
valve C, C, the exhausting end, and when the valve II of the supple-

page_text: mentary cylinder is moved from its present position steam from the Xend
of the supplementary cylinder escapes through the steam passages h, J,
into the right-hand end of the main cylinder A through the steam
passage P, but as soon as the valve C, C, moves and admits steam into the
right hand of the main cylinder it then brings the exhaust or X end of
the supplementary cylinder in communication with the steam end of the
main cylinder. The same result takes place in working the valve C, C,
when the piston a moves to the left-hand of the cylinder.
'
In some cases more and particularly in the larger class of engines
where the slide valve has a long distance to move, instead of connecting
or bringing the exhaust steam passages J; J, from the supplementary
cylinder into communication with the steam passages P, P¹, at their
sides as represented, the exhaust passage J, J', are turned up and brought
out through the main valve seats at e, e, at the sides of the steam
receiving passages P, P¹, as shown at cach end of the valve seat in
Figures 1 and 3. This is done for the purpose of governing the opening
and closing of the ports e, e, leading to the supplementary cylinder by
the ends of the valves C, C, so as to permit a free escape of steam from
the supplementary cylinder to insure a certain and positive motion of
its piston E, and thereby the valve C, C, as before described, before the
working steam in the large cylinder is brought in communication with
the exhaust end of the supplementary cylinder. The port e, e, in the
valve seat can be so made and arranged in relation to the motion of the
valve C, C, so that the valve may move the whole or any part of its
stroke before the working steam in the cylinder A is admitted to the
exhaust end of the supplementary cylinder.
The object of putting the exhaust end of the supplementary cylinder
in communication with the working steam in the main cylinder, in the
manner before stated, is to supply the supplementary cylinder with
steam in order to commence the motion of its piston, and as soon as
this takes place the supplementary cylinder is supplied with steam
through the openings in the rods or piston ends 9, g', as before stated;
also to prevent any leak or waste of steam from the supplementary
cylinder which would take place if its exhaust was continually kept in
communication with the exhaust port of the main cylinder A, owing to
the comparatively loose fitting of the steam joints around the piston
and its rods in the supplementary cylinder, which are made so for the

page_text: purpose of insuring its free and certain working at all times, and like-
wise by the valve openings through the pistons J, I'.
K is an arm for moving the valve C, C, in starting the engine if
required. This arm is arranged with the valve by placing it between
two flanges or lugs cast or otherwise attached to the valve, and is
worked by attaching it to a stem, which stem is made to pass out
through the side of the valve box B, and worked by a lever handle on
the outer end of the stem.
R, R, are valves which may be placed at one or both ends of tho
cylinder A, in connection with the steam passage P, P', leading from
the slide valve to the cylinder for regulating the flow of steam into the
cylinder, but so constructed as to permit a free escape of steam from the
cylinder after it performs its work at all times. The valves are used
when the cylinder is worked in a vertical position for pumping or other
purposes, as before stated, when as a rule there is more work to do by
the up stroke than down stroke of the piston, and in such cases in order
to give a uniform motion to the piston in both directions the check
valves R, R, are placed at the ends of the cylinder for regulating tho
flow and quantity of steam into it; for that purpose these valves are
connected to screw stem T, provided with collars S, the collars work in
recesses in the valves which admits of the valves moving upon the
stem to open to their full area at all times for the free escape of steam
from the cylinder, at the same time the valves may be closed to any
limit between entirely shutting off and opening them to the full extent
of their area for admitting steam to the cylinder.
Figure 4 represents another form of check valve to be used in the
steam passages of the cylinder for the same purpose, the screw stem o
moves a slide block V in a suitable recess, to which block is attached a
hinge valve W as represented, this valve is so arranged in the steam
passage of the cylinder leading from the end of the cylinder to the
valve that it will open to the full extent of its area to permit a free
escape of steam from the cylinder after performing its work, while it
can be closed to any extent for admitting steam to the cylinder to suit
the amount of work required to be done. The structure and application
of this valve to use will be understood by referring to the Drawing
without further specifying it.

page_text: The figures on Sheet 2 represent different views of an arrangement of
engine and pump for forcing water through high. lifts and more. par-
ticularly intended for mining purposes. Figure 1, Sheet 2, is a vertical
longitudinal view through the steam cylinder and pump bowels;
Figure 2 is a top view of the cylinder and pump bowels with the valve
box removed showing the steam valve and the arrangement of ports for
working it; Figure 3 is a transverse sectional view through the steam
cylinder and valve box; Figure 4 is an end elevation of the engine and
pump complete, and Figures 5 and 6 are transverse sectional views.
through the ends of the steam cylinder showing the arms or levers
against which the piston presses for moving the valve of the supple-
mentary cylinder.
A is the steam cylinder provided with a suitable constructed piston, to
which are attached hollow piston rods F, F, working through stuffing
boxes at each end of the cylinder as represented, the outer ends of
these rods are made to perform the function of pump plungers or
pistons, and work in the pump bowels E at each end of the cylinder,
as fully shown in Figure 1. Any suitable constructed pump valve
arrangement may be attached to the pump bowels E at the openings G, G.
The working of the slide valve C, C, of the engine by the piston of the
supplementary cylinder D is done in the same manner as that before
described on Sheet 1. The arrangement of the engine and pump on
Sheet 2 will be fully understood without further description.
The Figures on Sheet 3 represent an engine to which the valve
improvements are attached for working a blowing cylinder; Figure 1
Sheet 3 is a side elevation of an engine and blowing cylinder; Figure 2
is a top view of the same; Figure 3 is an end elevation of the end of
the blowing cylinder, and Figure 4 is a sectional view of the head of the
blowing cylinder through the valve chambers in line with a, b, in
Figure 3.
A is the steam cylinder provided with the improved valve arrange-
ment; B is the blowing cylinder; C, C, are the inlet air valve chambers
constructed in the heads or ends of the blowing cylinder; D, D, aro
the outlet air valve chambers, likewise constructed in the heads of
the cylinder, a section of which is shown in Figure 4; F is the outlet
openings from the cylinder to which the pipe is attached for conducting
the air to the furnace or for any other purpose to which it may be
applied.

page_text: Having thus described the nature of my Invention and manner of
performing the same, however, I do not confine myself to the use of any
exact form or relative arrangements of ports as the same may be varied
to suit different sizes and structures of engines and purposes to which
they may be applied, but what I claim is,-
First. The manner of working or moving the slide valves of steam
engines as specified in the foregoing Specification.
Secondly. The arrangement of check valves R, R, or their equivalent
in the steam passage of the cylinder for regulating the working pressure
of steam admitted to one or both ends of the cylinder for the purposes 1
herein-before stated.
In witness whereof, I; the said Martin Benson, have hereunto set
my hand and seal, this Fifth day of November, in the year of
our Lord One thousand eight hundred and seventy.