IMPROVEMENTS IN VALVES AND PARTS CONNECTED THEREWITH FOR DIRECT ACTING STEAM ENGINES
Year: 1873

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine,
Lake, & Co., Patent Agents, Southampton Buildings, London, for
the Invention of "IMPROVEMENTS IN VALVES AND PARTS CONNECTED
THEREWITH FOR DIRECT ACTING STEAM ENGINES."-A. communication
from abroad by George F. Blake, of Boston, Massachusetts, United
States of America.
.
Sealed the 22nd July 1873, and dated the 7th February 1873.
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition,
on the 7th February 1873.
I, WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co.,
Patent Agents, Southampton Buildings, London, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN VALVES AND PARTS
CONNECTED THEREWITH FOR DIRECT ACTING STEAM ENGINES," a communication,
to be as follows:-
This Invention relates to the valves and ports of direct acting engines
for the purpose of obtaining a perfectly, sure, and regular movement,

page_text: and overcoming difficulties heretofore experienced in this class of engines,
particularly in the variety known as "automatic" usually applied to steam
pumps. In such engines it is common to use a main slide valve moved
by a piston operated by steam admitted by the action of an auxilliary
valve which is moved directly by the main piston.
The said improvements consist in arranging the main slide valve upon
a movable seat which is itself a valve, and is provided with suitable
ports so that it may operate as the main valve of the engine under
certain circumstances when the ordinary valve would fail; and further,
in improvements in the arrangement of the auxilliary valve and
ports, and in the construction of the motive piston or plunger. The
ports of the said movable seat are enlarged at the lower side of the
movable seat, and communicate with the main ports of the engine.
The upper face of the said movable seat is arranged to form the seat
of the main slide valve. The lower face also rests upon the upper part 1
of the main cylinder containing the main ports. I prefer that the
auxiliary valve for operating the motive piston should form a part of
the movable seat.
On each side of the main body of the movable seat I arrange wings,
one having ports arranged to admit steam to the ends of the motive
piston, and cut it off therefrom at proper times; the other provided with
ports operating to exhaust steam from the plunger or motive piston.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Robert Lake in the Great Seal Patent
Office on the 6th August 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of February, in the year
of our Lord One thousand eight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Robert Lake, Her special licence
that I, the said William Robert Lake, my executors, administrators, and
с

page_text: assigns, or such others as I, the said William Robert Lake, 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 "IM-
PROVEMENTS IN VALVES AND PARTS CONNECTED THEREWITH FOR DIRECT ACTING
STEAM ENGINES," a communication to me from abroad by George F.
Blake, of Boston, Massachusetts, United States of America, upon the
condition (amongst others) that I, the said William Robert Lake, 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 William Robert Lake, 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, reference being had to the accom-
panying Drawing forming a part of this Specification:-
This Invention relates to the valves and ports of direct acting engines
for the purpose of obtaining a perfectly, sure, and regular movement,
and overcoming difficulties heretofore experienced in this class of engines,
particularly in the variety known as "automatic" usually applied to
steam pumps. In such engines it is common to use a main slide valve
moved by a piston, which is operated by steam admitted by the action
of an auxilliary valve which is moved directly by the main piston.
These improvements consist in arranging the main slide valve upon
a moveable seat which is itself a valve, and is provided with suitable
ports so that it may operate as the main valve of the engine under
certain circumstances when the ordinary valve would fail; and further,
in certain improvements, in the arrangement of the auxilliary valve and
ports, and in the construction of the motive piston or plunger.
Figure 1 is a section of the upper part of the steam cylinder, showing
the valves and ports.

page_text: Figure 2 is a plan of the moveable seat without its ports.
Figures 3 and 4 are diagrams showing the arrangement of the auxilliary
valve and ports.
B is the main slide valve of an automatic engine; A is the motive
piston for driving the same; C is the movable seat provided with 5
ports c, d, e, which are enlarged at the lower side of the movable
seat C, and communicate with ports f, g, h, which are the main ports
of the engine. The upper face of the movable seat C is arranged
to form the seat of the valve B, the lower face also rests upon the
upper part of the main cylinder containing the ports f, g, h. The 1
auxilliary valve for operating the main piston I prefer to construct
upon and forming a part of the movable seat C, as shewn in Figures
2, 3, 4, which I will now describe.
On cach side of the main body M of the movable seat I arrange
wings m, n, one having ports arranged to admit steam to the ends 1
of the motive piston A, and cut it off therefrom at proper times, is shown
at Figure 4; the other provided with ports operating to exhaust steam
from the plunger or motive piston, as shown at Figure 3.
In the event of any failure of the main valve B to move with
sufficient rapidity to reverse the motion of the main piston before 2
it shall have arrived at the end of the cylinder, the movable scat C
acts as the main valve of the engine, for by the passage of the same
over its ports steam is admitted by the passage of the bridge p or p¹
beyond the end of the seat, admitting steam into the ports c or e.
The action of the auxiliary valve, shown in Figures 3 and 4, is as 2
follows:-Steam is admitted by the passage of the port O over one
of the small ports s, t, to one end of the cylinder containing the
motive piston A, while at the same time it is exhausted from the
opposite end of the motive piston cylinder by the passage of one
of the ports v, w, over one of the small ports x, y; the ports v, w, 3
communicating directly with the exhaust port of the movable seat C,
and the ports x, y, communicating with the ends of the motive piston
cylinder, as shown. The entrance of the small exhaust passages x, y,
with the cylinder of the motive piston is at such a point that the
motive piston passes over and cuts off the same for the purpose of 3
cushioning. By this division of the steam and exhaust communi-
cations operating independently of each other, I am able to use free

page_text: entrance ports with the motive piston cylinder, while at the same time
all purposes of cushioning are equally well served.
In all usual cases the operation of the main piston upon the movable
seat with its auxilliary valves, will cause the motive piston to reverse
the engine, as will be seen by the foregoing description; but if by
reason of the high velocity of the main piston or otherwise, the motive
piston does not carry over its valve with sufficient rapidity to prevent
the main piston striking on its cylinder head. The direct action of the
piston of the engine carries the movable seat over so far that steam is
admitted into the port c or the port e, as before mentioned. Thus, the
piston is kept from striking the head as the steam thus admitted
cushions and arrests the motion of the piston before it has arrived
at the end of the cylinder; and further, by the movement of this
movable seat or valve C the ingoing steam is cut off at a point much
earlier in the stroke than it would be if controlled by the plunger valve
only, thus slackening the main piston near the end of its stroke.
It is not essential to the operation of the movable seat and other
ports that the auxiliary valve shall be of the construction described,
although I prefer this construction, nor is it essential that it be on the
plane of the main valve, or even in the same valve chest.
Having thus fully described the said Invention as communicated
to me by my foreign correspondent, and the manner of performing the
same, I wish it understood that I claim,—
First. A movable valve seat provided with ports arranged to operate
in connection with the ordinary valve of the engine, substantially as
set forth.
Second. The wings m, n, arranged on both sides of the main valve
for the purpose of containing ports and bridges for operating the plunger
or motive piston A.
Third. The arrangement of the port O and bridges 1, 2, operating
in connection with ports s, t, for the purpose of admitting steam to
move the motive piston, and cutting off the same therefrom at proper
times.
Fourth. The arrangement of two ports v, to, and bridges 5, 6, 7,
operating in connection with ports x, y, to control the exhaust from
the motive piston.

page_text: Witness,
JAMES EDWARDS,
8, Southampton Buildings,
London.
W. ROBT. LAKE. (L.S.)