Year: 1885

page_text: The following clerical errors in the Original Specification having been
amended by the Patentec with the consent of the Comptroller, the
printed Specification will now read as under :-

page_text: Improvements in Means for Operating the Valves of Steam and
other Engines.
I ROBERT LUNAN WEIGHTON of 26 Heaton Road in the City and County of
Newcastle on Tyne Engineer do hereby declare the nature of said Invention for
"IMPROVEMENTS IN MEANS FOR OPERATING THE VALVES OF STEAM AND OTHER
ENGINES" to be as follows:-
According to my Invention I operate the valves of steam and other engines by
the action of the steam or working agent applied directly that is to say without
the intervention of driving gear from an external part of the Engine as has
hitherto been the general practice, the distribution of the steam or working agent
for this purpose being effected by the valves themselves in the ordinary process of
working the Engines;-I effect the regulation of the motion of the valves by
connecting them to a crank or eccentric shaft or the like, the rotation of which may
be governed by connection with the crank shaft or connecting rod or other suitable
moving part of the Engines and I provide means for altering the admission of the
steam which actuates the valves so as to effect the reversal of the motion of the
Engines.
My Invention is applicable to various types and kinds of Engines but I will
more particularly describe it with reference to triple expansion steam engines
having three cylinders viz: a high pressure cylinder an intermediate cylinder and
a low pressure cylinder the piston rods from which act on cranks at or about equal
angles from each other; and from this description the general nature of my
Invention will be readily understood.
Each valve spindle is provided at each end with a piston working steam tight
(or nearly so) in a cylinder on the valve-casing-This cylinder is open at one end
to the valve-casing and is connected at the other end by means of pipes or passages
with each of the other main cylinders or steam ports; the particular cylinder or
port with which it is connected at any one time being governed by a valve, a cock,
or other means, which can be operated to effect the reversal of the motion of the
Engines. The ends of both cylinders of the high pressure valve are connected
with the intermediate and low pressure main cylinders or steam ports; the ends
of both cylinders of the intermediate valve are connected with the high pressure
and low pressure main cylinders or steam ports; and the ends of both cylinders of
DI 777

page_text: the low pressure valve are connected with the high pressure and intermediate main
cylinders or steam ports; all by suitable pipes or passages-The valve spindles are
carried through the valve pistons or otherwise and are all connected by suitable
means to a valve shaft having three cranks or eccentrics at the same angles or
nearly the same angles as the cranks of the main crank shaft, and rotating in the
same direction as the main shaft-The valve shaft may be connected to the main
shaft, or to other parts of the Engines most suitable, by a connecting rod or rods,
by an eccentric rod or rods, or by gearing the connections being so arranged as to
permit of reversal of the Engine motion, which is effected by changing the
connections of the valve cylinders and the main cylinders or steam ports, by means
of the cocks, valves or other devices before mentioned.
To go in one direction-and assuming for illustration that the high pressure
crank leads, and that the intermediate and low pressure follow in order,—the high
pressure valve cylinders are connected with the low pressure main cylinder or
steam ports, the intermediate valve cylinders with the high pressure main cylinder
or steam ports and the low pressure valve cylinders with the intermediate main
cylinder or steam ports.
To go in the opposite direction, the connections are altered so that the high
pressure valve cylinders are connected with the intermediate main cylinder or
steam ports, the intermediate valve cylinders with the low pressure main cylinder
or steam ports and the low pressure valve cylinders with the high pressure main
cylinder or steam ports.
An expansion valve or valves may be driven from the valve shaft by means of a
crank or eccentric giving the requisite phase of motion.
"
The first part of my Invention viz the operating of the valves by means of the
motive fluid applied direct in the manner described in the foregoing illustration
may be employed in connection with existing valve gears, such as "Link Motion'
the "single eccentric" or other gears. These gears would in this case fulfil the
function of the valve shaft and its connections with a moving part of the Engines,
as described in the foregoing and which valve shaft and connections constitute the
second part of my Invention. Reversal of motion would be effected in the usual
way, with this addition that the connections of the various valve cylinders with
the main cylinders would be changed in the process of reversing, as described in
the foregoing illustration.
My Invention is applicable in its entirety to all Engines having more than two
cranks and to a limited extent it is also applicable to Engines of two cranks.

page_text: Improvements in Means for Operating the Valves of Steam and
other Engines.
I ROBERT LUNAN WEIGHTON of 26 Heaton Road in the City and County of
Newcastle on Tyne Engineer, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
According to my Invention I provide the valves of steam or other engines by
the action of the steam or working agent applied directly (that is to say) without
the intervention of driving gear from an external part of the engine as has hitherto
been the general practice) the distribution of the steam or working agent for this
purpose being effected by the valves themselves in the ordinary process of working
the engines, and I effect the regulation of the motions of the valves by connecting
them to a crank or valve shaft or the like, the motion of which is regulated by
connection with the main crank shaft of the Engines through the intervention of a
regulator of suitable construction and I provide means for altering the admission
of the steam which actuates the valves so as to effect the reversal of the motion
of the engines.
The leading principle of my invention is based upon the fact that for any engine
of more than two cranks-say for an engine of three cranks set at angles of 120°
-the phase of motion of any one piston is coincident with the phase of motion of
the valve of the following piston (the steam being cut off at from to of the
stroke) The same steam which drives the first piston is therefore exactly adapted
in its distribution for driving the valve of the following piston.
This invention is applicable to various types and kinds of engines but I will now
particularly describe it with reference to the accompanying drawings as applied to
triple expansion steam engines having three cylinders videlicit a high pressure
cylinder an intermediate pressure cylinder, and a low pressure cylinder, the rods
from which act on cranks at, or about, equal angles from each other, and from
this description, the general nature of my invention will be readily understood.
Figures 1 and 2 shew sections at right angles to each other through an ordinary
low pressure valve of the piston description, with driving cylinders and driving
pistons, valve shaft, passages and regulators, applied according to my invention.
Figures 3 and 4 are sections at right angles to each other shewing in detail a
method by which the motion of the valves may be regulated by the motion of the
engine crank shaft. Figures 5 to 10 shew how my invention may be applied to
certain types of Engines as hereinafter explained. Each valve spindle D is
provided at each end with a piston (A and A²) the said pistons working steam
tight (or nearly so) in cylinders (B B³) on the valve casing covers. Each cylinder
is open at one end to the valve casing and is connected at the other end by means
of pipes or passages (C, C³) with each of the other main cylinders or steam ports,
the particular main cylinder or port with which it is connected at any time being
governed by a valve, a cock or other means (not shewn on the drawing) which
valves or cocks can be all operated together by hand to effect the reversal of the

page_text: motion of the engines. The ends of both cylinders of the high pressure valve are
connected with the intermediate and low pres-ure main cylinders or ports, the ends
of both cylinders, of the intermediate valve are connected with the high pressure
and low pressure main cylinders or ports, and the ends of both cylinders of the
low pressure valve are connected with the high pressure and intermediate main
cylinders or ports, all by pipes or passages such as those at C C³. The valve
spindles D are carried (at one end) through the valve casing cover and are all
connected by suitable means to a valve shaft E, having cranks or eccentrics at the
same angles or nearly the same angles as the respective cranks of the main crank
shaft, and rotating in the same direction as the main shaft.
The reversal of the engine motion is effected by changing the connections of the
valve cylinders and the main cylinders or steam ports, by means of the cocks,
valves, or other devices before mentioned. To go in one direction (and assuming
for illustration that the high pressure crank leads, and that the intermediate and
low pressure cranks follow in order):-the high pressure valve cylinders are
connected with the low pressure main cylinder or steam ports by means of the
passages C; the intermediate valve cylinders with the high pressure main cylinders
or ports, and the low pressure valve cylinders with the intermediate main cylinders
or ports.
To go in the opposite direction the connections are altered so that the high
pressure valve cylinders are connected with the intermediate main cylinders or
ports by means of the passages C, the intermediate valve cylinders with the low
pressure main cylinders or ports, and the low pressure valve cylinders with the
bigh pre-sure main cylinders or ports. If required, an expansion valve or valves
may be driven from the valve shaft by means of a crank or eccentric, giving the
requisite phase of motion and suitably arranged to admit of the reversal of the
motion of engines-This arrangement is shewn on figures 5, 6, and 7 (hereinafter
referred to), as applied to horizontal engines.
The valve shalt E, is driven entirely by the valve rods D, the valve pistons
being made of such proportions as to ensure (when the steam is fully admitted to
them) that they will have a tendency to move faster than the maximum speed of
the engines. The valve shaft having a tendency to overrun the main engine crank
shaft, is prevented from doing so by being connected to the main shaft through the
intervention of a regulator F, (shewn in detail in Figures 3 and 4), which acts on a
secondary short shaft G, in line with the valve shaft E. The said shaft G is provided
with a ciank pin K through which the shafts E and G operate upon each other.
The crank più K and its bush work in a slot which carries two plungers L, M.
The valve shaft E is in action continually pressing forward upon the shaft G and,
in order to give some elasticity to this pressure a spring may be inserted in the
plunger M. as shewn in Figure 3. The shaft G is connected with the Main Engine
crank shaft. This connection may be by means of spur or bevel gearing by
Eccentric rods, connecting rods or coupling rods, or by other means capable of
insuring that the shaft G will revolve in unison with the main Engine crank shaft.
In figures 3 and 4 a means of effecting the aforesaid connection is shewn, which
consists in providing the shaft G with two cranks H, H at right angles (or at any
other more convenient angle) which cranks are connected by the rods J J to two
eccentrics which are fastened to the main engine shaft at an angle equal to the
angle of the cranks H. H. The shaft G must therefore move in unison with the
main engine shaft. The arrangement of the plungers L and M and their connection
with the crank pin K all contained within the regulator F is such as to permit the
shafts E and G to rotate relatively to each other through an angle of 180° plus
twice the lap and lead angle, that is, from the ahead to the astern position as
indicated by dotted lines in Fig. 3 If required, an expansion valve or valves may
be driven by means of an eccentric or crank on the shaft G giving the requisite
phase of motion. In this case the shaft G and regulator F would necessarily be
placed at the high pressure end of the cylinders as indicated for the sake of
illustration in figures 8 9 and 10 hereinafter described.

page_text: The rap and lead angie can De reauny august
threaded screw N.
The vacant space about the plungers is completely filled with oil or other
suitable liquid which has to be forced through grooves from one end O to the
other end P when any relative angular rotation takes place between the shafts E
and G.
The action of the whole arrangement is thus:-Assume the engines to be going
ahead. The steam acting alternately on the pistons A, A' through the passages
CC drives the valves, the range of the motion being limited and regulated by the
cranks on the shaft E. The diameter of the pistons A. A² will be such as to give a
surplus of pressure over and above that required to overcome the resistance of
the valves at their maximum speed. This surplus pressure transmitted to the
shaft E by at least three valves working at equal angles (or at nearly equal angles)
serves three ends :-
First. It ensures that the shaft E will revolve uniformly.
Second. It enables each crank to turn the centre readily.
Third. It provides the power necessary to drive an expansion valve where such
is required.
The surplus pressure here referred to may be reduced to a minimum by
regulating the admission of the steam to the valve cylinders by means of the
reversing valves before mentioned.
The valve shaft E driven by the various valve rods, and tending to run faster
than the engines, drives the secondary shaft G, through the connection shewn in
the regulator. The shaft G is prevented from running faster than the engines by
means of its connections with the engine crank shaft. The valve shaft E though
not driven by the main engine shaft is therefore constrained to revolve in unison
with it. When going ahead the two shafts E and G revolve as one piece in the
relative position shewn in Figures 3 and 4.
This
When the notion is to be reversed the steam connections to the valve pistons
through the passages c, c² are changed by the means previously referred to."
has the effect first of stopping the rotation of the valve shaft E and therefore of
the engines, and second of starting the valve shaft and regulator F to rotate in the
reverse direction. This it can do through an angle of 180 degrees plus twice the
lap and lead angle before it is checked by the secondary shaft G.
When the valve shaft E has revolved through this angle it has assumed the
position for asteru motion indicated on Figure 3 The engine crank shaft will now
revolve in the astern direction permitting the secondary shaft G to follow in the
same direction under the pressure of the valve shaft as before and the two shafts
will now revolve as one piece in the astern direction.
In the process of reversing, the oil in the regulator has to be forced from one end
of the plunger to the other and back again. This prevents reversal taking place so
suddenly as to cause damage and the speed of reversal will be determined by the
cross sectional area of the oil grooves.
From this description it is therefore clear that the shaft E drives the shaft G, the
function of the shaft G with its coupling rods J J or with any other suitable means
which may be adopted for connecting the shaft G with the Engine shaft being
simply to prevent the shaft E from running faster than the Engine crank shaft-
Under no circumstances according to my arrangement will it be possible for the
main crank shaft of the Engines to drive the shaft E.
Hence the rods J. J or other means which may be adopted for effecting the
aforesaid connection between the shaft G and the Engine shaft have only to
withstand the surplus pressure transmitted from the valve cylinders.
This arrangement of valve gear may be used as a Governor to control or limit
the speed of the Engines in the following way.
For any desired speed of the Engines, say the normal speed, let steam be
admitted (by means of the valves or cocks before mentioned) to the valve cylinders
in sufficient quantity to drive the valves and with them the valve shaft at the

page_text: desired normal speed, and let the admission of steam be so regulated that the valves
will have no tendency to move faster than the desired normal speed. Any increase
of engine speed due to diminution of lead will therefore be checked owing to the
valves not following up at the increased speed.
The operating of the valves by means of the steam applied direct as described in
the foregoing illustration may be employed in combination with existing valve
gears such as "link motion" the "single eccentric" or other gears-These gears
would in this case fulfil the function of the valve shaft and its connection with the
crank shaft as hereinbefore described in the foregoing.
Reversal would be effected in the usual way with this addition that the con-
nections of the valve cylinders with the main cylinders would be changed in the
process of reversing as described in the foregoing Specification.
My Invention is applicable in its entirety to all Engines having more than two
cranks, the different cranks being placed at angles to each other suitable for the
various valve motions.
Figures 5 to 10 serve to illustrate how my Invention may be conveniently
applied to Engines-I here shew what I at present believe to be the most con-
venient mode of carrying out my Invention as applied to the types of engines
here shewn but I do not bind myself to the arrangements shewn by these figures
which are merely given to more clearly elucidate the nature and application of my
Invention.
Figures 5, 6 and 7 shew how my Invention may be conveniently applied to
horizontal triple expansion Engines the said figures being respectively a front
elevation an end elevation and a plan of a set of short stroke high speed triple
expansion horizontal steam engines with my valve gear applied thereto, an expan-
sion valve being shewn as being driven from the valve shaft and the regulator is
at the low pressure end of the cylinders.
Figures 8, 9 and 10 shew how my Invention may be applied to vertical triple
expansion engines the said figures being respectively a front elevation an end
elevation and a plan of a set of triple expansion vertical steam engines of the
ordinary marine type with my gear applied thereto, an expansion valve being
shewn as being driven from the secondary shaft which is placed with the regulator
at the high pressure end of the cylinders.
In all these figures 1 indicates the valve shaft 2 the regulator 3 the secondary
shaft 4 the coupling rods 5 the expansion valve rod 6 the reversing valves and
7 the reversing wheel.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
First. The driving of the valves of Steam and other engines by the same body
of motive fluid which drives the main pistons without the intervention of any
additional valves; each valve being the distributor of motive fluid for its neighbour
valve substantially as hereinbefore described.
Second. In Steam and other Engines the provision of means for driving the
valves entirely and solely by the motive fluid acting on the valve pistons direct,
and the connecting of all the valve rods, to one valve crank shaft, which being
driven by the surplus power provided in the valve Cylinders, serves to equaliza
and regulate the motion of all the valves, all substantially as hereinbefore described
and illustrated by the accompanying Drawings.
Third. In Steam and other engines of the kind referred to in the preceding
claiming clause the combination of the regulator herein before described and
illustrated in figures 3 and 4, the said regulator being so constructed that while
the valves move with the same speed of revolution as the Engine crank shaft, they
are not driven by the Engine Crank Shaft but entirely by the motive fluid acting
in the Cylinders provided for that purpose; all substantially as herein before
described and illustrated-by the accompanying Drawings.

page_text: Fourth. The reversing of the Engines arranged as claimed by the preceding
claiming clauses by simply changing the sources whence the Steam flows to the
several valve pistons by means of hand valves or cocks, thus dispensing altogether
with an auxiliary reversing Engine, for even the largest sizes of Engines substan-
tially as herein before described.
Fifth. The means for adjusting or altering the lead, and to a certain extent the
cut off in all the cylinders, consisting of the screw N, on the regulator as herein-
before described.
Sixth. The arrangement and combination of parts as hereinbefore described and
illustrated by the accompanying drawings for driving the valves of Steam or
other Engines.