IMPROVEMENTS IN DIRECT-ACTING PROVISIONAL SPECIFICATION
Year: 1874

page_text: LETTERS PATENT to John Hamilton, of the Firm of Forbes and
Hamilton, of Smethwick, in the County of Stafford, Engineers
and Machinists, for the Invention of "IMPROVEMENTS IN DIRECT-ACTING
PROVISIONAL SPECIFICATION left by the said John Hamilton at the
Office of the Commissioners of Patents, with his Petition, on the
15th October 1874.
I, JOHN HAMILTON, of the Firm of Forbes and Hamilton, of
Smethwick, in the County of Stafford, Engineers and Machinists, do
hereby declare the nature of the said Invention for "IMPROVEMENTS
IN DIRECT-ACTING PUMPS WORKED BY STEAM OR COMPRESSED AIR," to be as
follows:-
My Invention consists of the improvements herein-after described
in constructing and actuating the valves of the steam or compressed
air cylinders of direct-acting pumps, the object of my said improvements

page_text: being to effect the automatic working of the said valves in a simple and
efficient manner.
I will describe my improvements as applied to a direct-acting steam
pump.
I construct the valve of the steam cylinder of three parts, namely,
of two short pistons placed at each end of the steam chest or valve
chamber, and a longer cylindrical hollow piston situated between the two
short outer pistons. The middle cylindrical valve has in it two ports,
the said ports being separated by a solid central diaphragm. These
ports serve alternately for conveying steam to and permitting of the
escape of the exhaust steam from the same end of the cylinder. The
end piston valves in the steam chest are without ports, and are of
somewhat greater diameter than the middle cylindrical valve. The
end piston valves have about half the length of stroke of the middle
valve.
The steam and exhaust ports of the steam chest and steam cylinder
are arranged as follows:-The steam port is made in the middle of the
steam chest, and on either side of the said steam port is an exhaust port.
By the reciprocating motion of the middle cylindrical valve, effected in
the manner herein-after explained, the two ports are alternately brought
opposite the steam port and the exhaust port in that end of the steam
chest to which the cylindrical valve has advanced. Two other ports
are also made in the ends of the steam chest, which ports open respec-
tively into the ends of the steam cylinder and convey steam to or remove
the exhaust from the said cylinder. In addition to the last-described
ports two other small ports are made at the extreme ends of the steam
chest, the said small ports opening into the steam öylinder. By means
of these small ports steam passes from the steam cylinder into the steam
chest for working the valve. When the steam piston is at the top or
cover end of the steam cylinder, the steam port is open to that end
of the cylinder, and the exhaust port to the opposite end of the
cylinder.
On the steam piston making its stroke to the opposite end of the
cylinder, the compound valve is automatically worked in the following
manner :-As soon as the steam piston has passed the small port at the
bottom end of the cylinder steam enters by the said port into the steam
chest, and acting on the piston valve causes the latter partly to advance

page_text: the cylindrical valve and reverse the position of the ports, that is, cause
the port in the valve which was open to the steam port to come
opposite the exhaust port and the reverse. Steam now entering the
cylindrical valve acts upon and further advances it so as to completely
open the steam port; the said steam at the same time presses back the
valve piston to its normal position at the extreme end of the steam
chest, and thereby completely opens the exhaust port. The pressure
of the steam also keeps the cylindrical valve and piston valve apart.
The steam entering the steam cylinder the piston makes its return
stroke, and when it has passed the small port by which steam was
supplied to the piston valve, the steam in the cylinder now being open
to the piston valve an equilibrium of pressure is established on the said
piston valve and the valve at the opposite end of the steam chest, which
is open to the exhaust is free from the back pressure of the steam which
is being supplied to the steam cylinder at the opposite end. The same
action of the compound valve which I have described takes place at both
ends of the steam cylinder.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Hamilton in the Great Scal Patent Office on
the 8th April 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HAMILTON, of the Firm of Forbes and Hamilton, of Smethwick, in
the County of Stafford, Engineers and Machinists, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of October, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Hamilton, Her special license
that I, the said John Hamilton, my executors, administrators, and
assigns, or such others as I, the said John Hamilton, 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

page_text: Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
DIRECT-ACTING PUMPS WORKED BY STEAM OR COMPRESSED AIR," upon the con-
dition (amongst others) that I, the said John Hamilton, 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 5
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 John Hamilton, do hereby declare 1
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 of the improvements herein-after described in
constructing and actuating the valves of the steam or compressed air 1
cylinders of direct-acting pumps, the object of my said improvements
being to effect the automatic working of the said valves in a simple and
efficient manner..
I will describe my improvements as applied to a direct-acting steam
pump.
2
I construct the valve of the steam cylinder of three parts, namely, of
two short pistons placed at each end of the steam chest or valve chamber,
and a longer cylindrical hollow piston situated between the two short
outer pistons. The middle cylindrical valve has in it two ports, the said
ports being separated by a solid central diaphragm. These ports serve 2
alternately for conveying steam to and permitting of the escape of the
exhaust steam from the same end of the cylinder. The end piston valves
in the steam chest are without ports, and are of somewhat greater
diameter than the middle cylindrical valve. The end piston valves have
rather more than half the length of stroke of the middle valve.
The steam and exhaust ports of the steam chest and steam cylinder
are arranged as follows:-The steam port is made in the middle of the
steam chest, and on either side of the said steam port is an exhaust port.
By the reciprocating motion of the middle cylindrical valve effected in
the manner herein-after explained the two ports in it arc alternately 3
brought opposite the steam port and the exhaust port in that end of the

page_text: steam chest to which the cylindrical valve has advanced. Two other
ports are also made in the ends of the steam chest, which ports open
respectively into the ends of the steam cylinder, and convey steam to or
remove the exhaust from the said cylinder. In addition to the last-
described ports two other small ports are made at the extreme ends of
the steam chest, the said small ports opening into the steam cylinder.
By means of these small ports steam passes from the steam cylinder into
the steam chest for working the valve. When the steam piston is at the
top or cover end of the stram cylinder the steam port is open to that
end of the cylinder, and the exhaust port to the opposite end of the
cylinder.
On the steam piston making its stroke to the opposite end of the
cylinder the compound valve is automatically worked in the following
manner :-As soon as the steam piston has passed the small port at the
bottom end of the cylinder steam enters by the said port into the steam
chest, and acting on the piston valve causes the latter partly to advance
the cylindrical valve and reverse the position of the ports, that is, cause
the port in the cylindrical valve which was open to the steam port to
come opposite the exhaust port, and the reverse steam now entering the
cylindrical valve acts upon and further advances it, so as to completely
open the steam port; the said steam at the same time presses back the
valvo piston to its normal position at the extreme end of the steam
chest, and thereby completely opens the exhaust port. The pressure of
the steam also keeps the cylindrical valve and piston valve apart. The
steam entering the steam cylinder the piston makes its return stroke,
and when it has passed the small port by which steam was supplied to
the piston valve, the steam in the cylinder now being open to the piston
valve, an equilibrium of pressure is established on the said piston valve,
and the valve at the opposite end of the steam chest which is open to
the exhaust is free from the back pressure of the steam which is being
supplied to the steam cylinder at the opposite end. The same action of
the compound valve which I have described takes place at both ends of
the steam cylinder.
Having ouplained the nation
314
Intention Till
nieeed
to

page_text: a is the steam chest or valve chamber in which my improved com-
pound valve works, the said valve consisting of two short similar pistons
b, c, respectively placed at each end of the steam chest a, and a longer
cylindrical hollow piston d situated between the said pistons b, c. The
hollow piston d is open at its ends, and is divided into two parts by the
diaphragm . At the sides of each open end of the piston d openings
d³, d³, are made. I will herein-after call the middle piston d the cylin-
drical valve and the outer pistons b, c, the piston valves. In the
cylindrical valve d are two ports d', d³, separated by the central
diaphragm d². By means of the said ports d', d³, steam is alternately
conveyed to and exhaust steam permitted to escape from the same end
of the steam cylinder e. The cylindrical valve d and the end piston
valves b, c, have the respective diameters represented, and the interior
of the valve chamber a is constructed for the working therein of the
said valves d, b, and c. The end piston valves b, c, are without ports,
and have about rather more than half the length of stroke of the cylin-
drical valve d. The motion of the cylindrical valve is limited by the
stopf working in a depression in the said valve. 9 is the steam port
situated in the middle of the steam chest, and h, i, are the exhaust ports
on either side the said steam port 9 (see Figure 2), the said exhaust
ports opening into a common passage. By the reciprocating motion of
the cylindrical valve d the ports d', d³, in the valve d are alternately
brought opposite the steam port g and one or other of the exhaust ports
h, i. k, l, are ports in the ends of the steam chest, which open respec-
tively into the ends of the steam cylinder e, and convey steam to or
conduct the exhaust steam from the said steam cylinder; m, n, are two
small ports at the extreme ends of the steam chest a, which ports m, n,

page_text: also open into the steam cylinder e, as represented in Figure 1. By
means of the small ports m, n, steam passes from the steam cylinder e
into the steam chest a for working the compound valve.
The action of the valve mechanism is as follows:-When the parts are
in the respective positions represented in Figure 1, the steam piston p is
at the top or cover end of the steam cylinder e, and the steam port y
is open by means of the port d' in the cylindrical valve d and the port k
to the said top or cover end of the steam cylinder, and the exhaust port i
is open by means of the port d³ in the cylindrical valve d, the opening &³
in the end of the said valve d, and the port with the opposite end of
the steam cylinder e. As soon as the steam piston p, on making its
stroke in the direction of the arrow, has passed the small port n, steam
from the cylinder e enters by the said port n into the steam chest a, and
acting on the outer face of the piston valve c, causes the said valve to
I move in the direction of the arrow q, and to partly advance the cylin-
drical valve d in the direction of the said arrow. This partial advance
of the cylindrical valve d brings the port d³ in it opposite the steam
port g, and the port d' opposite the exhaust port, the exhaust port i
being closed. Steam now entering the cylindrical valve d by the ports g
and ď³, acts upon and further advances the said valve d in the direction
of the arrow q, so as to completely open the steam and exhaust
ports d', d³. The steam entering the valve d, at the same time acting
upon the inner face of the valve piston c, forces it back to its normal
position, or the position represented in the Drawing, and thereby com-
pletely opens the port 7, which had been partly covered by the said piston c.
The pressure of the entering steam keeps the cylindrical valve d and
piston valve c apart, as represented with respect to the parts at the left-
hand side of the valve chamber a. The steam and exhaust passages
being thus reversed steam enters the steam cylinder e, and the steam
piston p makes its return stroke, moving in a direction contrary to that
indicated by the arrow in the cylinder e. When the steam piston p on
its return stroke passes the small port n, steam from the cylinder e now
enters behind the piston valve c. The steam is thus made to press on
both sides of the said piston valve c, which is thereby in equilibrium,
and that half of the valve d which is open to the exhaust is free from
the back pressure of the steam which is being supplied through the
ports g, d³, l. When the steam piston p has arrived at the position
represented in Figure 1, steam from the cylinder e entering the steam

page_text: chest by the small port m acts upon the piston valve b, which by its
motion partly advances the cylindrical valve d, and reverses the position
of the ports in the said cylindrical valve, which ports are completely
opened, and made to take the positions represented in the Drawing by
the entering steam acting upon the cylindrical valve and the piston
valve, as herein-before explained with respect to the action of the parts
at the right-hand end of the valve chamber.
Figure 5 represents in longitudinal vertical section a modification of
my Invention, in which the ends of the cylindrical valve d are closed
instead of being open, and additional ports in connection with the ports
passing to each end of the cylinder are made for conveying steam to the
steam chest for completely reversing the position of the cylindrical
valve, and returning to its normal position one or other of the piston
valves b, c.
Figure 6 represents a plan of the face of the steam chest and cylinder,
and Figure 7 represents in longitudinal and cross section the cylindrical
valve detached. The ports or passages which convey steam from the
steam cylinder e from the ports k, l, to the closed ends of the cylindrical
valve d aro marked 1, 8. The ports k, l, in this modification open into
the steam chest near the middle theroof instead of near the ends. The
action of the valve mechanism represented in Figures 5, 6, and 7 is the
same as that already described, and corresponding parts are marked with
the same letters of reference. The ports r, s, may be omitted, and in
place thereof small openings may be made in the ends of the cylindrical
valve d for admitting steam between the ends of the piston valves b, c,
and the said cylindrical valve d.
Figure 8 represents in longitudinal vertical section and Figure 9 in
horizontal section an arrangement of my Invention, in which instead of
a hollow cylindrical valve a slide valve and plunger are used in com-
bination with the end piston valves. t is the slide valve fixed to the
middle of the plunger u, the enlarged ends u³, ², of the said plunger
being acted upon alternately by the piston valves b, c, and steam admitted
by the ports r, s, to reverse the position of the said valve t. In this
arrangement the valve chest or chamber a is divided by the par-
titions a², a³, into three parts, the central part constituting the steam
chest proper, which is in communication with the ports k, l, and the
outer parts of the said valve chest constituting chambers in which the

page_text: piston valves b, c, work. v is the exhaust pipe and wo is the pipe
supplying steam to the valve chest. The action of this valve mechanism
is essentially the same as that already described.
Figure 10 represents in longitudinal vertical section and Figure 11 in
horizontal section another modification of my Invention in which each
valve piston b, c, is provided with a rod b', c², for working the slide
valve t. The action of the said piston valves b, b³, c, c³, for alternately
reversing the position of the slide valve t will be readily understood by
an examination of the Drawing. The ports are the same as in the
last-described arrangement, and are marked with the same letters of
reference.
Although I have only described my Invention in combination with a
steam cylinder of a direct-acting pump, yet my said Invention is equally
applicable to the cylinders of direct-acting pumps worked by compressed
air, and although I have represented the application of the piston valves
at the ends of the main valve to the working of those modifications of
slide valves to which they are more especially applicable, yet the said
piston valves may be applied to the working of slide valves of direct-
acting pumps of other constructions.
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 herein described and illustrated, as
the same may be varied without departing from the nature of my
Invention, but I claim as my Invention of improvements in direct-acting
pumps worked by steam or compressed air,―
First. The construction and combination of parts herein-before
described and illustrated in Figures 1, 2, 3, 4, 5, 6, and 7 of the accom-
panying Drawing for automatically working the valves of the said pumps,
that is to say, the construction and arrangement of the cylindrical or
hollow valve d and piston valves b, c, and the arrangements of the ports
used with the said valves, the said valves d, b, and c, and parts in con-
nection therewith, being combined and worked substantially as described
and illustrated.
Secondly. The modification described and illustrated in Figures 8 and 9
of the accompanying Drawing, in which the piston valves are used in
conjunction with a combined slide valve and plunger.

page_text: Thirdly. The modification described and illustrated in Figures 10 and 11
of the accompanying Drawing, in which the piston valves are provided
with rods which operate a slide valve.
Lastly. The application of the piston valves herein-before described
and illustrated to the working of the slide valves of direct-acting pumps
of other constructions than the slide valves herein-before described and
illustrated in the accompanying Drawing.
In witness whereof, I, the said John Hamilton, have hereunto set
my hand and seal, this Fifth day of April, in the year of our
Lord One thousand eight hundred and seventy-five.
Witness,
RICHARD SKERRETT,
Clerk to George Shaw,
Birmingham.
JOHN HAMILTON. (L.S.)