IMPROVEMENTS IN VALVE MOTIONS FOR STEAM OR OTHER ENGINES
Year: 1884

page_text: I, ROBERT WYLLIE, of the Hartlepool Engine Works, Hartlepool, in the County
of Durham, Engineer, do hereby declare the nature of my said invention for
IMPROVEMENTS IN VALVE MOTIONS FOR STEAM OR OTHER ENGINES to be as
follows, that is to say :---
"
My said Invention comprises an improved and simplified arrangement or
construction of valve motion or gear for working the valves of steam or other
engines.
My improved valve motions are well suited for any class of engine but are
especially adapted for screw engines of the inverted cylinder type having valves at
the side of the cylinders over the condenser. A single eccentric on the crank shaft
and fitted with a strap and rod is used for working the valve or valves of one
cylinder. The eccentric rod is jointed to or suspended by a link centered on a pin
which is adjustable into various positions for making the engines go ahead or astern
or for altering the cut off. The movements for working the valve are transmitted
from a joint on the eccentric rod either more or less remote from the eccentric than
the joint connecting the rod to the suspension link. It is the transverse motion of
the joint which is transmitted and the transmission is effected by a compensating
Link connecting the joint to a lever arm which may be on a rocking shaft having
ou it another lever ara connected to the valve spindle. Or the two lover arms inay
be in one piece centered on a stud or pin the arius being in this case of an oblique
form in order that the ends may be in proper positions for connection to the valve
rod and eccentric rods respectively.
The piu forming the centre of the suspension link to which the eccentric rod is
jointed is by preferenco on a controlling lever which has its centre in the plano
passing through the centre line of the eccentric rod when the crank is at its dead
points. When this controlling lever is in its central position the motion of the
compensating liuk joint on the eccentric rod conveys a certain motion to the valve,
and the parts are proportioned so that the motion transmitted corresponds to the
lap and lead of the valve. The direction of the engine's motion depends on the
side of its middle position to which the controlling lever is set and the grade of cut
off depends on the extent to which it is moved from its middle position.
'
EDMUND HUNT,
Applicant's Agent,

page_text: I, ROBERT WYLLIE of the Hartlepool Engine Works, Hartlepool in the County
of Durham, Engineer do hereby declare the nature of my invention for "IMPROVE-
MENTS IN VALVE MOTIONS FOR STEAM OR OTHER ENGINES" and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
My said Invention has for its object to provide an improved, efficient and
simplified arrangement, or construction of valve motion, or gear for working the
valves of steam or other engines and is applicable to any class of engine but is
especially suitable for screw propeller engines of the inverted cylinder type having
the distribution valves at the side of the cylinders over the condenser.
In carrying out my Invention a single eccentric, on the crank shaft and fitted
with a strap and rod, is used for working the valve or valves of each cylinder. The
eccentric rod is placed. centrally at an angle other than a right angle to the line of
motion of the valve and is guided in the arc of a circle which may most con-
veniently be effected by jointing it to or suspending it by a link centred on a pin
which is adjustable into various positions for making the engines go ahead or
astern or for altering the cut off. The movements for working the valve are
transmitted from a joint on the eccentric rod either more or loss remote from the
eccentric than the joint connecting the rod to the suspension link. 'It is the
transverse motion of the joint which is transmitted and the transmission is effected
by a compensating link connecting the joint to a lever arm which may be on a
rocking shaft having on it another lever-arin connected to the valve rod. Or the
two lever arms may be in one piece centred on a stud or pin, the arms being in
this case of an oblique form in order that the ends may be in proper positions for
connection to the valve rod and compensating link respectively.
The compensating link is an essential and distinguishing featuro of my improved
valve gear, the said link being placed and proportioned, relatively to the other
parts, in a manner to produce practically equal openings of the ports at the top and
bottom of the cylinder, without its being necessary to have unequal ports or a
valve with differently formed ends or other corrective device such as is met with
in some existing arrangements of valve gear.
And in order that my said Invention and the manner of performing the same
may be properly understood I hereunto append two sheets of explanatory drawings
to be hereinafter referred to and showing various applications of my improved
valvo motion.
Figures 1 and 2 on sheet 1 of the accompanying drawings are elevations at right
angles to each other shewing parts of an arrangement of inverted cylinder, scrow-
propeller engines with one modification of my improved valve motion applied
thereto Figures 3 and 4, show other modes of applying the motion to similar
engines whilst Figures 5 to 9 shew the application of the motion to engines with
horizontal or inclined cylinders. Figure 10 on sheet 2 is an enlarged explanatory
diagram corresponding to the modification of my valve motion applied as shown in

page_text: Figures 1 and 2 In these drawings the same reference numerals are used to mark
the same or corresponding parts wherever they are repented.
In the arrangement shewn in Figures 1 and 2, the valve rod 11, is connected to
one oblique arm, 12, of a lever having another oblique arm 13 and centred on a
horizontal pin or in an equivalent manner so as to have its axis of motion parallel
to the crank shaft 14, whilst the end of one arm 12 is in the vertical plane passing
at right angles to the crank shaft and through the centre of the cylinder and the
end of the other arm 13 is in a vertical plane parallel to that in which the eccentric 15
is situated... The eccentric 15 is fixed on the shaft 14, in such a position relatively
to the crank, and its rod 16 is suspended and situated when in a central position
at an angle other than a right angle to the line of motion of the valve, in such a
way that the said rod can be connected to the lever arm 13, by a comparatively
short link 17, which I term a compensating link because in consequence of its
angular movements in transmitting the motion it compensates for or neutralises the
inequalities which without its peculiar relative arrangement and proportion would
be produced by the other parts of the gear in the action of the valve at the
opposite ends of the stroke. The length of the compensating link should be equal
to or about equal to the length of the radius of the arc through which the eccentric
rod is guided by the hereinafter mentioned link 18 or its equivalent.
The eccentric rod 16 is suspended by a link 18 from the outer end of a controlling
lever 19 which has its centro 20 in the plane passing through the centre line of the
eccentric 15 and through the centre of the crank shaft 14 when the crank is on
either of its dead points. The middle or neutral position of this controlling lover 19
is at right angles to the plane just referred to, and it is moved, by any suitable
gear (but which it is not necessary to shew in the drawings, as it may be of the
ordinary kind) to one side or the other of that middle position accordingly as the
engines are required to go ahead or astern and to a greater or less distance
accordingly as it is wished to cut off the steam at a later or earlier part of the
stroke.
In the diagram figure 10, the lines 19" 19", 19° shew the middle and two extremo
positions of the controlling lever, the lines 18", 18b; 18° shew three positions of the
link 18, by which the eccentric rod 16, is suspended from the end of the controlling
lever 19, the lines 16 show eight positions of the eccentric rod; the dotted oval-21
showing the path of the upper end of that rod, the lines 17° 17° 17° 17ª show
different positions of the compensating link and the lines 12" 12", 12°, 12d and
13ª, 13, 13º, 13ª show corresponding positions of the levers 12 and 13. The shaded
parts between the lines 12 correspond to the port openings at the top and bottom
of the cylinder and indicate the practical equality of those openings, and it will be
found that there is a similar equality when the controlling lever; 19, is placed in
other of its positions, and also when the compensating link, 17 is connected to the
eccentric rod 16 at a point nearer the eccentric than the joint of the suspension
link 18.
Figures 3, and 5 show diagrammatically arrangements with the compensating
link 17, connected to a joint on the eccentric rod 16 nearer the eccentric than the
joint of the suspension link, 18; and figures 1, 2, 4, 6, 8 and 9 show arrangements
with the compensating link, 17 connected to a joint on the eccentric rod 16 further
from the eccentric than the joint of the suspension link 18. All these arrange-
ments are substantially the same and will without further explanation be well
understood from the preceding description the corresponding parts being all marked
with the same referenco numerals.
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
The combination of parts forming my improved valve motion and consisting of
an eccentric with its rod placed centrally at an anglo other than a right angle to

page_text: the line of motion of the valve and guided in the arc of a circle and connected by
a compensating link to a lever through which the movements are transmitted to
the valve so that the said link has such a compensating action as to give equal
or as nearly as possible equal port openings and cuts off at each end of the
valve, substantially in the manner herein before described and illustrated by the
accompanying drawings.