IMPROVEMENTS IN ACTUATING THE SLIDE VALVES OF STEAM AND OTHER FLUID ENGINES
Year: 1876

page_text: LETTERS PATENT to John Nicholas Floyd, of Handsworth, in the County of
Stafford, Machinist, for the Invention of "IMPROVEMENTS IN ACTUATING THE
SLIDE VALVES OF STEAM AND OTHER FLUID ENGINES."
Sealed the 9th February 1877, and dated the 25th November 1876.
PROVISIONAL SPECIFICATION left by the said John Nicholas Floyd at the
Office of the Commissioners of Patents on the 25th November 1876.
JOHN NICHOLAS FLOYD, of Handsworth, in the County of Stafford, Machinist.
"IMPROVEMENTS IN ACTUATING THE SLIDE VALVES OF STEAM AND OTHER FLUID
ENGINES."
My Invention consists of the improvements, herein-after described, in actuating
the slide valves of steam and other fluid engines.
My Invention is particularly applicable to direct-acting steam pumping engines,
and I will describe it in connection with a direct-acting steam pumping engine.
The slide valve is moved by two small pistons connected together and working
in cylinders formed in the ends of the valve chest. A small hole is drilled through
each piston, which holes supply steam to them for moving the slide valve, as herein-
after described. Two piston valves are placed, one at each end of the cylinder, pre-
ferably in removable bushes, and seated on suitable seats. When these valves are
lifted steam can escape by means of a passage formed in the steam cylinder casting
from the corresponding cylinder formed in the steam chest, into the steam cylinder
passages, and thence into the exhaust port. The heads of the piston valves are
The stalk passes
larger than their stalks, and the bushes form cylinders for them.
nearly steam-tight through the bottom of the bush, and its end forms the valve.
Holes are drilled in the ends of the cylinders communicating between the bore of
When the
the cylinder and the under side of the enlarged end of the piston valve.
piston reaches one or other end of its stroke it passes over the corresponding hole,
and the steam which is moving it raises the corresponding piston valve; the steam
is then exhausted from the corresponding cylinder formed in the end of the steam
chest, and the small pistons are driven over by the excess pressure in the cylinder
at the other end of the steam chest. The steam for this purpose is supplied by
leakage through the holes drilled through the small pistons, as herein-before

page_text: mentioned.
A hole drilled lengthwise right through the piston valve admits steam
to the top of the piston valve immediately steam enters that end of the cylinder;
the valve is thus returned to its seat. Its own weight also tends to bring it to
its seat, and a spring may be employed to urge it in the same direction.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Nicholas Floyd in the Great Seal Patent Office on the 19th May
1877.
JOHN NICHOLAS FLOYD, of Handsworth, in the County of Stafford, Machinist.
"IMPROVEMENTS IN ACTUATING THE SLIDE VALVES OF STEAM AND OTHER FLUID
ENGINES."
My Invention consists of the improvements herein-after described in actuating
the slide valves of steam and other fluid engines.
My Invention is particularly applicable to direct-acting steam pumping engines,
and I will describe it in connection with a direct-acting steam pumping engine.
The slide valve is moved by two small pistons connected together and working
in cylinders formed in the ends of the valve chest. A small hole is drilled through
cach piston, which holes supply steam to them for moving the slide valve, as herein-
after described. Two piston valves are placed one at each end of the cylinder,
preferably in removable bushes, and seated on suitable seats. When these valves
are lifted steam can escape by means of a passage formed in the steam cylinder
casting from the corresponding cylinder formed in the steam chest, into the steam
cylinder passages, and thence into the exhaust port. The heads of the piston valves
are larger than their stalks, and the bushes form cylinders for them. The stalk
passes nearly steam-tight through the bottom of the bush, and its end forms the
valve. Holes are drilled in the ends of the cylinders communicating between the
bore of the cylinder and the under side of the enlarged end of the piston valve.
When the main steam piston reaches one or other end of its stroke it passes over
the corresponding hole, and the steam which is moving it raises the corresponding
piston valve; the steam is then exhausted from the corresponding cylinder formed
in the end of the steam chest, and the small pistons are driven over by the excess
pressure in the cylinder at the other end of the steam chest. The steam for this
purpose is supplied by leakage through the holes drilled through the small pistons,
as herein-before mentioned. A hole drilled lengthwise right through the piston
valve admits steam to the top of the piston valve immediately steam enters that
end of the cylinder; the valve is thus returned to its seat. Its own weight also
tends to bring it to its seat, and a spring or steam pressure may be employed to
urge it in the same direction.
I will now proceed to describe, with reference to the accompanying Drawing, the
manner in which the same is to be performed.
Figure represents in longitudinal section the steam cylinder of a direct-acting
steam pumping engine, the slide valve of the said cylinder being actuated according
to my Invention; and Figure 2 represents a cross section of a modification of a part
of the same.
at is the slide valve actuated by the small pistons b, 63, the said pistons working
in the cylinders c, c, made at the ends of the valve chest d. In each of the
pistons b, b, is a small hole or passage, through which holes steam from the
chest passes to the cylinders c, e, and presses on the outer faces of the said
pistons b, By means of the steam thus allowed to pass into the cylinders c, c²,
the slide valve & is moved in the manner herein-after described. The two pistons
b, b, and slide valve a move together. At each end of the steam cylinder q is a
piston valve f similarly constructed, and each having the same function. The said
piston valves, work in removable hollow bushes or small cylinders g, g, screwed

page_text: into the steam cylinder casting. The heads of the piston valves ff, work in the
hollow bushes or cylinders g, g, as represented. The stalk of each of the piston
valves passes through the bottom of the bush g, and the end of the said stalk
forins the valve; the said end seating itself on the seat in the steam cylinder
casting.
In the steam cylinder casting are passages i, i, which are in communication by
means of the seats h, h, of the valves ff, with the steam cylinder passages or
ports, so that when the valves, fare alternately lifted, steam from one or
other of the small cylinders c or in the valve chest can escape through the
passage i, lifted valve f, and seat h, to the port or passage jor 1, and from thence to
the exhaust port k, with which for the time being the passage jor jis in com-
munication, as herein after more fully explained. Opening near each end of the
steam cylinder q is a small hole or passage 1, P².
Each of these small holes or
passages forms a communication between the bore of the steam cylinder q and the
under side of the head of the valve f. In the axis of each of the valves f, f, a hole
is drilled for adınitting steam to the upper side of the head of the valve for
returning the said valve to its seat. This axial passage or hole is indicated in dotted
lincs.
Other arrangements are herein-after described for ensuring the return of the
valves ff, to their seats at the proper times.
The action of the parts is as follows:-When the steam piston has arrived at
the end of its stroke in the direction indicated by the arrow in Figure 1, the several
parts occupy the respective positions represented in the said Figure 1, that is to
say, the slide valve a has been reversed, the right-hand end of the steam cylinder q
is open to steam by the passage or port j, and the left-hand end is open to the
exhaust by the passage or port, the valves f, f, are closed, and steain from the
steam chest & passes by means of the holes e, e, in the pistons b, b, into the
cylinders c, c, and presses on the ends of the said pistons b, b. The said pistons
b, b, are thus in equilibrium, and the slide valve is maintained in its reversed
position until the end of the stroke of the main steam piston 7.
When the main steam piston in making its back stroke reaches the left-hand
end of the steam cylinder q it passes over the hole or small passage in the
cylinder ; and the said hole or passage is open to steam in the said cylinder q,
which steam is conducted by the said hole or passage to the under side of the head
of the valve fat the left-hand side of the cylinder, and by pressing on the said head
raises the valve from its seat. By the raising of the said valve the passage i at
the left-hand end of the cylinder is open to the passage or port and exhaust
port, and the steam in the cylinder c² in the valve chest is exhausted therefrom
through the said ports or passages j and , and seat h. By the exhaustion of the
cylinder the excess of steam pressure in the opposite cylinder e acting on the
piston drives over the slide valve a, and with it the pistons b, b, and the ports
are reversed, steam being open by the port to the left-hand end of the main
cylinder q, and exhaust by the port to the right-hand end of the said main
cylinder q. On the reversal of the ports the steam from the port 2 (now delivering
steam) enters the hollow seat at the left-hand of the cylinder, and passes up the
hollow stem of the raised valve to the upper side of the head of the said valve, and
by pressing on the said head returns the valve to its seat, and thereby cuts off
communication between the small cylinder c and the passage i. When the steam
piston in its back stroke in the direction of the arrow passes over and opens the
passage, the valve f at the right-hand end of the steam cylinder q is lifted, and
the slide valve a is again reversed in the manner herein-before described.
The closing of the valves f, f, may be effected by means of springs p, p, working
in recesses in the bush stoppers n, n, bearing upon small pistons m, m, and the
latter upon the heads of the valves f, f; or a passage o (Figure 2) may be made
in the bush g and stopper n to convey steam from the passage i to the upper side
of the small piston m, and cause the latter to press the valve to its seat.
Having now described the nature of my Invention, and the manner in which the

page_text: 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
the improvements in actuating the slide valves, of steam and other fluid engines,
herein-before described and illustrated in the accompanying Drawing, that is to say,
the combination of the valve f, passage i, and hole or small passage or 1, and
parts immediately connected with them at each end of the steam-cylinder casting,
with small perforated pistons and be connected with the slide valve working in
cylinders c, c, at the ends of the valve chest, steam being supplied to each of the
said cylinders of the valve chest by the small passages in the said pistons b, b, and
the exhaustion of the steam from one of the cylinders of the valve chest and the
reversal of the slide valve by the excess steam pressure in the other cylinder of the
valve chest being effected by the opening of one or other of the valves f by steam
delivered from the main steam cylinder when the main steam piston has made the
required travel, substantially as described and illustrated.
In witness whereof, I, the said John Nicholas Floyd, have hereunto set my
hand and seal, this Eighteenth day of May, in the year of our Lord One
thousand eight hundred and seventy-seven.
Witness,
RICHARD SKERRETT,
Clerk to George Shaw,
Birmingham.
JOHN NICHOLAS FLOYD. (L.S.)