IMPROVEMENTS IN MOTIVE-POWER ENGINES
Year: 1869

page_text: LETTERS PATENT to Robert Douglas and Lewis Grant, both of
Kirkcaldy, in the County of Fife, North Britain, for the Invention
of "IMPROVEMENTS IN MOTIVE-POWER ENGINES."
Sealed the 29th April 1870, and dated the 5th November 1869.
PROVISIONAL SPECIFICATION left by the said Robert Douglas and
Lewis Grant at the Office of the Commissioners of Patents, with
their Petition, on the 5th November 1869.
We, ROBERT DOUGLAS and LEWIS GRANT, both of Kirkcaldy, in the
County of Fife, North Britain, do hereby declare the nature of the
said Invention of "IMPROVEMENTS IN MOTIVE-POWER ENGINES," to be as
follows, that is to say :-
These improvements relate to a special arrangement and construction
of apparatus for regulating the action of the valves of steam engines by
which the steam is admitted to and cut off from the cylinders.
The first part of these improvements consists in the application of a
lever, one end of which is connected to the engine governor and the
other end bored so as to vibrate upon the spindle of the valve, or upon

page_text: an intermediate or weigh shaft. The circumference or periphery of the
eye of said lever is eccentric to its bore, and on this eccentric projecting
eye another lever is fitted working slack upon it, and thus the second
lever vibrates eccentrically to the valve spindle or weigh shaft. Upon
this second lever two other links or levers are hinged, and to a pin
passing through their extremities the rod from the engine, eccentric,
wrist plate, or other apparatus for opening the valve is attached. Upon
the other extremities of the last-mentioned levers projections or tails are
formed, which catch upon other projecting pieces forming parts of two
other levers, the points of which are connected by a pin and rod to the
spring or other apparatus for closing the valve.
Various modifications of this apparatus may be employed. For
example, instead of a single lever being connected to the governor two
levers may be used, having their eccentric eyes projecting towards each
other, and each carrying a lever working slack on it. Between these
latter levers a single link or lever may be hinged, its extremity being
connected to the rod from the engine, eccentric, or wrist plate, a tail
piece or projection on this link or lever catching a projection on a dise or
lever, to the point of which the rod from the spring or other apparatus
for closing the valve may be attached. The links, levers, and other
parts are so arranged, connected, and disengaged as to regulate
automatically the cut-off and expansion of steam in the cylinder.
The second part of these improvements consists in closing the steam
valve when released from the detent catch by a movement derived
either from the steam cylinder and piston of the engine itself, or
from a subsidiary steam cylinder and piston expressly adapted for this
nurnose
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Douglas and Lewis Grant in the Great
Seal Patent Office on the 5th May 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT
DOUGLAS & LEWIS GRANT, both of Kirkcaldy, in the County of Fife,
North Britain, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of November, in the year

page_text: of our Lord One thousand eight hundred and sixty-nine, in the 33rd
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto us, the said Robert Douglas and Lewis Grant, Her special
license that we, the said Robert Douglas and Lewis Grant, our exe-
cutors, administrators, and assigns, or such others as we, the said Robert
Douglas and Lewis Grant, our executors, administrators, or 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 MOTIVE-POWER ENGINES," upon
the condition (amongst others) that we, the said Robert Douglas and
Lewis Grant, by an instrument in writing under our 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 we, the said Robert Douglas and Lewis Grant,
do hereby declare the nature of our 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 Drawings, and to the letters and figures marked thereon, that is
to say :-
Our improvements relate to a special arrangement and construction of
apparatus for regulating the action of the valves of steam engines by.
which the steam is admitted to and cut off from the cylinders.
The first part of these improvements consists in the application of a
lever, one end of which is connected to the engine governor and the
other end bored so as to vibrate upon the spindle of the valve, or upon
an intermediate or weigh shaft. The circumferance or periphery of the
eye of said lever is eccentric to its bore, and on this eccentric pro-
jecting eye another lever is fitted working slack upon it, and thus the
second lever vibrates eccentrically to the valve spindle or weigh shaft.
Upon this second lever two other links or levers are hinged, and to a
pin passing through their extremities the rod from the engine, eccentric,
wrist plate, or other apparatus for opening the valve is attached. Upon
the other extremities of the last-mentioned levers projections or tails are

page_text: formed, which catch upon other projecting pieces forming parts of two
other levers, the points of which are connected by a pin and rod to the
spring or other apparatus for closing the valve.
Various modifications of this apparatus may be employed; for
example, instead of a single lever being connected to the governor, two
levers may be used having their eccentric eyes projecting towards each
other, and each carrying a lever working slack on it. Between these
latter levers a single link or lever may be hinged, its extremity being
connected to the rod from the engine, eccentric, or wrist plate, a tail
piece or projection on this link or lever catching a projection on a disc
or lever, to the point of which the rod from the spring or other apparatus
for closing the valve may be attached. The links, levers, and other parts
are so arranged, connected, and disengaged as to regulate automatically
the cut-off and expansion of steam in the cylinder.
The second part of these improvements consists in closing the steam
valve when released from the detent catch by a movement derived either
from the steam cylinder and piston of the engine itself, or from a
subsidiary steam cylinder and piston expressly adapted for this purpose.
And in order that our said Invention may be properly understood, we
now proceed more particularly to set forth the system, mode, or manner
in or under which the same is or may be used or practically carried into
effect, that is to say :-
On the appended Sheet of Drawings Figure 1 is a part end elevation,
and Figure 2 a side elevation of a "Corliss " engine cylinder showing
our improved valve gearing applied thereto. Figure 3 is an enlarged end
elevation of the valve gearing; Figure 4 an enlarged side elevation
thereof, and Figure 5 also an enlarged side elevation with certain parts
of the mechanism removed in order that the remaining part may be
more clearly shown. On these different Figures corresponding parts are
indicated by the same letters of reference.
On Figures 1 and 2 M, M', are the boxes which contain the valves for
the admission of steam to the cylinder; N, N', the boxes in which the
exhaust valves are placed, and P a vibrating disc or wrist plate actuated
by an eccentric or other mechanism attached to the driving pin V. The
vibrating disc or wrist plate P is provided with pins or studs W, seen
more particularly at Figure 1, to each of which are attached one end of
the rods R, R', and S, S¹, respectively, the other ends of these rods
being fixed to the respective admission and exhaust valve levers. On

page_text: the spindles K of the steam valves levers A are placed, one end of each
of which is connected to the engine governor through the intervention
of the rods 0, 0, 0, as shown more particularly at Figure 2; or the
levers A may be placed on intermediate or weigh shafts, and connected
to the spindles of the valves by means of other levers. The cir-
cumference or periphery of the eyes of the levers A are eccentric to their
bores, particularly shown at Figure 5, and on these eccentric projecting
eyes other levers B are fitted, which levers work slack upon the eyes of
the levers A, and thus vibrate eccentrically to the valve spindle K. Two
other levers or links C, C', are hinged on each of the levers B by the
pins H, and a pin J is passed through the extremities of each pair of
these levers or links C, C¹, to which pins the rods R and R' from the
vibrating disc or wrist plate P are attached. At the other extremities
of the levers or links C, C', projections or tails D are formed, which
catch upon projecting pieces E forming part of or attached to other
levers F, the extremities of which levers are likewise connected by
pins G, to which the rods T in communication with the springs or other
mechanism for closing the valves are fixed. The projecting stopper I,
which makes up the space between the levers C and C¹ bearing on the
heel of the lever B, regulates the travel of the projecting point or tail D.
These links, levers, and other mechanism above described are so
arranged, connected, and disengaged as to regulate automatically the
cut-off and expansion of the steam in the cylinders. On the disc or wrist
plate P being vibrated either to one side or the other by the eccentric or
other mechanism attached to the pin V, the rod attached to that side of
the plate or disc towards which the vibration occurs causes the pro-
jecting points or tails D of the levers or links C, C', at that side to
engage with or catch on the projection E fixed to or forming part of the
lever F; by this means the valve spindle K is caused to oscillate, and
the steam valve in communication therewith to open, and steam
sufficient for the stroke of the piston is thereby admitted to the cylinder.
While the valve is opening the projecting points D are being gradually
moved outwards by the motion of the lever B upon the eye of the
lever A, the full side of its eccentric eye coming round until the points or
tails D are disengaged, and the valve immediately closed by the springs
or other mechanism in the box X through the intervention of the rods T
and lever F, as herein-before set forth. The vibrating disc or wrist
plate P at the same time actuates the exhaust valves N, N', through the
medium of the rods S, S', and levers U, as shown particularly at

page_text: Figure 2. The closing of the valves may be regulated by air pistons
and air regulating valves.
At Figure 6 is shown an end elevation of another modification of
this Invention; at Figure 7 a side elevation, and at Figure 8 a side
elevation with certain parts of the gearing removed in order more clearly
to show the remaining parts. On these Figures corresponding parts are
indicated by the same letters of reference. In this modification two
levers A. are employed to connect each of the steam valves with the
governor in lieu of one lever, as herein-before described and shown in
reference to the preceeding arrangement. These levers A, A, are placed
on the valve spindles K with their eccentric eyes projecting towards
each other, and on each of these eccentric eyes a lever B is fitted, which
works loose upon it. Between the levers B, B, a single lever or link C
is hinged by means of the pin H, the extremity of the lever or link C
being connected to the rod from the vibrating disc or wrist plate by the
pin J. The projecting point or tail piece D of the link or lever C
engages with or catches on the projection E fixed to or forming part of
the lever F, and by this means the valve is opened, as in the previous
modification, for the admission of steam to the cylinder, the rod to the
spring or other apparatus for closing the valve being connected to the
extremity of the lever F by the pin G. The lever C in this modification
is provided with a projection I on either side, which coming in contact
with the heels of the levers B, B, as shown, regulates the travel of the
projecting point or tail D, or the travel of the projecting point or tail D
may be regulated in any other suitable manner, it being understood that
we do not confine ourselves to any particular arrangement of the levers,
catches, or releasing gear herein-before described. A spring may also be
attached to the lever B bearing on the links C, C³, so as more rapidly to
throw the points D into gear with the nibs or projections E when moved
into position by the return motion of the rod from the wrist plate P.
In lieu of placing the cylinder in a horizontal position, as shown on
the appended Drawings, it may be placed vertically or in any other
convenient position.
Having now described the nature of our said Invention, and the
system, mode, or manner in or under which the same is or may be used
or practically carried into effect, we would observe in conclusion that
what we consider novel and original, and therefore claim as the
Invention secured to us by the herein-before in 'part recited Letters

page_text: Patent is, the actuating of the valves of steam or other engine cylinders,
and regulating their cut-off action by means of levers placed on the
valve spindles, or upon intermediate or weigh shafts, one or more of the
levers having the periphery of its or their eye or eyes formed eccentric
to the bore, and having another lever or levers vibrating on the said
periphery or peripheries as and for the purpose herein-before described,
or any mere modification thereof.
Patent is, the actuating of the valves of steam or other engine cylinders,
and regulating their cut-off action by means of levers placed on the
valve spindles, or upon intermediate or weigh shafts, one or more of the
levers having the periphery of its or their eye or eyes formed eccentric
to the bore, and having another lever or levers vibrating on the said
periphery or peripheries as and for the purpose herein-before described,
or any mere modification thereof.
In witness whereof, we, the said Robert Douglas and Lewis Grant,
have hereunto set our hand and seal, this Thirtieth day of
April One thousand eight hundred and seventy.