IMPROVEMENTS IN GOVERNORS FOR MOTIVE-POWER ENGINES
Year: 1884

page_text: I, WILLIAM MURDOCH, of Glasgow, in the County of Lanark, Engineer, do
hereby declare the nature of my said Invention for "IMPROVEMENTS IN GOVERNORS
FOR MOTIVE-POWER ENGINES," to be as follows:-
My Invention consists of improvements in valves and valve-actuating apparatus.
for governors or governor cylinders of the kind described in the Specification of
Letters Patent granted to me and dated 8th March 1883, N° 1245.
The improved apparatus comprises a hollow cylindrical valve, of a forin similar to
that described in the Specification above referred to, and therein designated the " relay
valve." This valve is divided by a longitudinal web or partition into two compart-
ments, which are open to the valve casing at the opposite ends, and each compartment
has a helical slot or port cut through its side. Outside this valve is fitted a second
cylindrical valve or shell, having ports cut in its side communicating with steam
admission and exhaust ports in the valve casing, and with the steam ports of the
governor cylinder. The valve casing can be made in the same casting as the cylinder,>
or separately and fixed to the cylinder. The steain and exhaust ports or passages are
cast all round the casing forming cells round the outer valve, which cells correspond
to the ports in the valve. The two valves are carried by separate spindles, which
project through suitable stuffing glands in each end of the valve casing, and they
are made to revolve in the same direction. The one valve spindle may be driven
direct, or by means of a band and pulleys or other suitable gearing, from a
separate motor arranged to run at a uniform speed, which motor may be a small
steam engine of any of the well known types, while the other valve spindle is
driven from the engine whose speed is to be controlled by the governor. The
steam port and the exhaust port in the outer valve communicating with one end of
the governor cylinder, are formed on opposite sides of the helical slot or port in one
compartment of the central valve, and the other two ports on opposite sides of the
helical slot in the other compartment, the helical ports in their normal position
lying at an angle between a steam and an exhaust port in the outer valve, in
which position the ports are closed. The slightest overrunning of the one valve in
relation to the other, however, opens the steain port or the exhaust to the one end
of the governor cylinder, and the exhaust or steam respectively to the opposite end,
and the piston of that cylinder is forced in one direction or the other, and through
the piston-rod acts on the throttle valve, expansion valve, or other supply valve of

page_text: the motive-power engine whose speed is to be regulated. The movement of the
piston is communicated through a suitable lever arrangement, to act on the central
valve spindle and impart to it a longitudinal movement in the same direction as
that of the piston. This movement of the central valve within the other takes the
helical ports out of the line of the steam or exhaust ports to which they are open
for the time being, and closes these ports so that the piston stops. The extent of
longitudinal motion of the central valve required to close the ports depends upon
the extent to which the ports have been opened by the one rotating valve
overrunning the other; and as the extent of movement of the piston must be
proportionate to that of the central valve and in the same direction, it is evident
that the motion communicated to the throttle valve or other valve of the main
engine will depend on the extent to which the one valve overruns the other, that is
on the difference of speed between the uniformly driven valve spindle and that
driven from the engine whose speed is to be governed, the throttle or other valve
being thus actuated to correct exactly any irregularities of speed of the main
engine.
Another modification of these valves is to make the internal valve so that the
steam is admitted from the centre instead of from the outside. This is done by
making the internal valve have the one side or compartment open all through, so
that the steam can pass right through, while the opposite side or compartment has
its ends closed, but is recessed out between the ends. Helical slots or ports are cut
in each compartment the same as before described, and the ports in the outer valve
or shell are so arranged that the helical slot in the steam side is at an angle
between the ports opening to the opposite ends of the steam cylinder, and the
helical slot on the exhaust side is at an angle between the exhaust ports and ports
opening to the opposite ends of the steam cylinder, so that when the one valve
overruns the other, steam is admitted to one end of the cylinder, and the other end
is open to the exhaust.
The arrangement of revolving valves described is also adapted for use as a
throttle valve or steam supply valve for the main engine or engines. For
convenience in applying the arrangement to the steam supply pipe, the form of
valve may be either cylindrical, a single or double cone, or globular. The ports
or orifices in the valves are over each other and open to the same extent so long as
the valves revolve at uniform speeds; but when one valve spindle overruns the
other, the valve orifices close on each other to a greater or less extent, according
to the variation of the main engine from the uniform speed at which it is intended
to run.

page_text: I, WILLIAM MURDOCH, of Glasgow, in the County of Lanark, Engineer, do
hereby declare the nature of my said Invention for "IMPROVEMENTS IN GOVERNORS
FOR MOTIVE-POWER ENGINES," and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :-
My Invention consists of improvements in valves and valve-actuating apparatus
for governors or governor cylinders of the kind described in the Specification of
Letters Patent granted to me and dated 8th March 1883, N° 1245.
The Invention is illustrated by the accompanying Drawings in which Figures 1
and 2 Sheet 1 are respectively a side elevation and an end elevation of a governor
or governor engine for operating the throttle valve of a large engine, and which is
fitted with a modification of my improvements. Figures 3 and 4 are respectively
a longitudinal section and an end elevation of a modified arrangement of my
improved governor. Figures 5, 6, 7, and 8 are views of details hereinafter referred
to. Figure 9, Sheet 2, is a sectional elevation of my Invention as applied to
operate direct a throttle valve or steam supply valve. Figures 10 and 11 are
transverse sections taken respectively on the lines 1 - 1 and 2 - - - - 2 in Figure 9.
- 3
The improved apparatus as illustrated in Figures 1 and 2 comprises a hollow
cylindrical valve a of a form similar to that described in the Specification above
referred to, and therein designated the "relay" valve. This valve a is divided by
a longitudinal web or partition into two compartments a¹ a², which are open to the
valve casing C at the opposite ends through the ports d in the valve b; and each
compartment a, a², has a helical slot or port a³ a cut through its side as shown
particularly in Figures 5 and 6, which are respectively a section on the line 3 - -
and a diagram of the circumferential surface of the valve a. Outside this valve a
is fitted a second cylindrical valve or shell b having steam and exhaust ports b¹ b²
cut in its side communicating with steam admission and exhaust ports d₁, d³, in the
valve casing C, and with the steam ports d, of the governor cylinder D, which
are simply prolongations or continuations of the end ports d of the valve casing C
and valve b. The valve casing C can be made in the same casting as the
cylinder D or separately and fixed to the cylinder. The end ports d'and the
steam and exhaust ports or passages d¹ d² are cast all round the casing the latter
forming cells round the outer valve b, corresponding to the position of the
ports bib in the valve b. The two valves a, b, are carried by separate spindles A
and B, which project through suitable stuffing glands in the ends of the valve
casing C and they are made to revolve in the same direction. The one valve
spindle A may be driven by means of a band and pulleys or other suitable gearing
from a separate motor arranged to run at a uniform speed, or direct as shown by
means of a motor E (as in some other governors) which may be a small steam
engine of any of the well-known types; while the other valve spindle B is driven
from the main engine whose speed is to be controlled by the governor, the driving
gear employed being a belt, rope, or band passing over a pulley F fixed on the
spindle B. The steam port and the exhaust port 61, 62, in the outer valve b
communicating with one end of the governor cylinder E are formed on opposite
sides of the helical slot or port a³ in one compartment a¹ of the central valve, and
the other two ports 61 62 on opposite sides of the helical slot at in the other
compartment a², the helical ports a¹ a³ in their normal position lying at an angle
between a steam port b¹ and an exhaust port 62 in the outer valve, in which
position the ports are closed, as is shown in Figures 5 and 8, which are a view of

page_text: the valve a developed or flattened out; while Figures 6 and 7 are sections through
the valves a, b, and valve chest C taken on the lines 3-3 in Figures 1 and 3
respectively. The slightest overrunning of the one valve a in relation to the
other b, (or vice versa), opens the steam port b' or the exhaust be to the one end of
the governor cylinder D, and the exhaust 6 or steam port b¹ respectively, to the
opposite end, and the piston D¹ of that cylinder is forced in one direction or
the other, and through the piston rod D' acts on the throttle valve, expansion
valve, or other supply valve of the motive-power engine whose speed is to be
regulated, and to which the end D³ of the piston-rod D2 is connected.
The
movement of the piston is communicated through a suitable arrangement of.
levers G, G', to act on the central valve spindle A and impart to it a longitudinal
movement in the same direction as that of the piston as in Figures 3 and 4, or at
right angles or other angle to it, as in Figures 1 and 2. This movement of the
central valve a within the other b takes the helical ports a³, a, out of the line
of the steam or exhaust ports 61 62 to which they are open for the time being, and
closes these ports so that the piston D' stops. The extent of longitudinal motion
of the central valve required to close the ports b' b³ depends upon the extent to
which the ports have been opened by the one rotating valve a or b overrunning
the other; and as the extent of movement of the piston D¹ must be proportionate
to that of the central valve a and in the same direction (the latter being controlled
by the former by the levers G G') it is evident that the motion communicated to
the throttle valve or other valve of the main engine will depend on the extent to
which the one valve overruns the other, that is on the difference of speed between
the uniformly driven valve spindle.A and that. B-driven-from-the-engine-whose-
speed is to be governed, the throttle or other valve being thus actuated to correct
exactly any inequalities of speed of the main engine.
Another modification of these valves, which is illustrated in Figures 3 and 4
consists in making the internal valve a so that the steam is admitted from the
centre instead of from the outside. This is done by making the internal valve
have the one side or compartment a' open all through, so that the steam can pass
right through, while the opposite side or compartment a has its ends closed, but
is recessed out between the ends. Helical slots or ports a³ a are cut in each
compartment in the same way as before described, and the ports 'be in the outer
valve or shell are so arranged that the helical slot a³ in the steam side is at an
angle between the ports 61 61 opening to the opposite ends of the steam cylinder
and the helical slot at, on the exhaust side is at an angle between the exhaust
ports and ports opening to the opposite ends of the steam cylinder so that when
the one valve overruns the other, steam is admitted to one end of the cylinder, and
the other end is open to the exhaust.
The arrangement of revolving valves described is also adapted for use as a
throttle valve or steam supply valve for the main engine or engines; such an
arrangement is shown in Figures 9, 10 and 11, Sheet 2. For convenience in
applying the arrangement to the steam supply pipe, the form of valves a, b, may
be either cylindrical as shown, or a single or double cone, or globular. The ports
or orifices a*b* in the valves are over each other and open to the same extent so
long as the valves revolve at uniform speeds; but when one valve spindle A or B
overruns the other the valve orifices *b* close on each other to a greater or less
extent, according to the variation of the main engine from the uniform speed at
which it is intended to run; the inner valve spindle A being in this example
driven by a band and pulley A' from the main engine and the outer valve b by
its spindle B from a small engine E running at any required constant speed. The
valves ab are enclosed or fitted to work within an outer brass liner h secured
within a valve casing H, which is formed with branches II for securing it to the
steam supply pipe of the engine as in other regulating valves. The two valves a
and b in all these arrangements are so fitted and coupled to each other that they
can only overrun or turn on each other to the extent of the transverse width of
the helical ports a³, at, (and a*, b±, in Figures 10, 11 and 12) in the valve a, so as

page_text: to open and close these to their respective steam and exhaust ports b1, b2, in the
valve b leading, for the time being, to the opposite ends of the cylinder D, while
allowing the valve a also to do this by its longitudinal motion, by a simple
arangement of overlapping segmental projections (or other equivalent) as A3 and
63 forined or secured on the rod A and the inner end of the valve b over each
other, so as to slide longitudinally and with a clearance between them to turn on
each other to the extent of the width of their ports, all as described, and shown
in the enlarged transverse section Figure 3A of these parts of the valves a and b
and their casing, and taken on the line 44 in Figures 1 and 3.
The valves a, b, in the various arrangements of governing apparatus herein
described may be of other forms than those illustrated; for example, they may be
made conical instead of cylindrical, or they may be made in the form of flat dises
arranged to rotate in the same direction and formed with ports which open or close
when one valve, cone, or disc overruns the other.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I desire it to be
understood that I do not claim the driving at a uniform speed by a separate
motor, the regulating valve of a cylinder for controlling the steam admission valves
of engines, but what I do claim is,―
First. The combination of parts forming the improved governor for motive
power engines, substantially as herein described and illustrated in Figures 1 to 8 of
the accompanying Drawings.
Second. In a governor or governor engine, the herein described arrangement of a
pair of steam-distributing valves of which one is rotated at any required constant
velocity and the other is driven from the main engine whose speed is to be
governed, substantially as herein described and illustrated.
Third. The combination of a pair of valves (a, b,) so arranged and operated that
they rotate in the same direction and that a variation of velocity of rotation of the
one in relation to the other effects or is accompanied by an opening or closing
of ports formed in the valves, substantially as and for the purposes herein set
forth.
Fourth. The arrangement of steam supply valve or throttle valve for steam
engines herein described and illustrated in Figures 9, 10, and 11 of the accompanying
Drawings.