Year: 1885

page_text: I, WILLIAM HAMILTON MARTIN, of 185 I Longwall Street Flushing in the
Kingdom of Holland, Engineer to the Royal Shipbuilding and Engineering works
"the Scheldt," Flushing, do hereby declare the nature of this invention to be as
follows:-
This invention has for object improvements in valve gear for oscillating engines
and relates to a method of working the valves by a combination of two motions,
one obtained from the cylinder, and another at right angles thereto. The latter
motion is by preference obtained from an eccentric on the crank shaft, but it may
be derived from another source, such for example, as a lever worked by the
piston rod.
In one arrangement according to this invention, the sliding link of the ordinary
valve gear, (usually called the quadrant), is employed, but instead of being con-
strained to move in a uniform path, it is capable of being rotated or tilted so that
the slot is no longer situated symmetrically to the centre line of the engine. It is
supported and guided by means of two links or radius bars connected to levers at
the opposite sides of a weigh shaft. By partially rotating this shaft the quadrant
is tilted one way or the other, the amount of angle determining the point of
cut-off. When the quadrant is in its central position the motion of the block in
the curved slot has no effect upon the valve, which has then only the motion due
to the rise and fall of the quadrant under the action of the eccentric. But if the
quadrant be tilted either way the motion of the block will be increased.
The motion due to the tilting of the quadrant determines the point of cut-off,
and the direction of the tilting determines the direction of rotation of the engine.
The lead, however, remains constant, as the angle given to the quadrant has little
or no effect on the valves at the point at which the crank passes the centres.
If the point of suspension of the quadrant be not in the same plane as the line
of centre of the slot, there will be a slight lifting motion in tilting the quadrant.
To compensate for this the arms or radius bars by which the quadrant is guided
should be so placed that it is tilted about an imaginary centre between the centre
of the slot and the point of suspension.
Or one of the arms or links may be dispensed with, and the other connected to
a projecting horn or bracket on the quadrant in such a way that a slight tilting

page_text: action is produced as the quadrant is moved up and down. The effect of this action
is to cause the points of cut-off, above and below the piston, to be approximately
equal.
.
It is not requisite, however, to obtain the compound motion, that the existing
arrangement of quadrant should be adopted, and in place of it a system of links
and levers may be employed. The end of the valve lever is pivotted to a link,
which at its other end is connected by a radius bar to an arm on the weigh shaft.
This link I will call the first link. To the first link there is pivotted a second link,
the other extremity of which is pivotted to a point at or near the end of the
eccentric rod, which is guided by a radius bar in an approximately straight line.
To compensate for the slight error the second link may be connected to the
eccentric rod above the point of connexion of the radius rod, or both it and the
radius rod may be pivotted at a point somewhat higher than would be otherwise
necessary.
It will be evident that valve gear according to this invention may be variously
modified to suit different forms and arrangements of engines.
Dated this 8th dox of Dombor 100K
W. LLOYD WISE,
Agent for the Applicant.

page_text: Improvements in Valve Gear for Oscillating Engines.
I, WILLIAM HAMILTON MARTIN, of 185 I Longwall Street, Flushing, in the
Kingdom of Holland, Engineer to the Royal Shipbuilding and Engineering works
"the Scheldt" Flushing, 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 :-
This invention has for object improvements in valve gear for oscillating engines
and relates to a method of working the valves by a combination of three motions,
one obtained from the cylinder, another at right angles thereto and a third which
I call the compensating motion, as it serves to equalize the points of cut off above
and below the piston; this motion is obtained by different methods according to
the system employed. The second motion is by preference obtained from an
eccentric on the crank shaft, but it may be derived from another source such for
example as a lever worked by the piston rod. In one arrangement according to
this invention, the sliding link of the ordinary valve gear, (usually called the
quadrant), is employed, but instead of being constrained to move in a uniform
path it is capable of being rotated or tilted so that the slot is no longer situated
symmetrically to the centre line of the engine. It is supported and guided by
means of two links or radius bars connected to levers at the opposite sides of a
weigh shaft. By partially rotating this shaft the quadrant is tilted one way or
the other, the amount of angle determining the point of cut off. When the
quadrant is in its central position the motion of the block in the curved slot has
no effect upon the valve, which has then only the motion due to the rise and fall
of the quadrant under the action of the eccentric. But if the quadrant is tilted
either way the motion of the block will be increased.
The motion due to the tilting of the quadrant determines the point of cut-off,
and the direction of the tilting determines the direction of rotation of the engine.
The lead, however, remains constant as the, angle given to the quadrant has little
or no effect on the valves at the point at which the crank passes the centres.
The compensating motion in this arrangement is produced by the quadrant
being tilted about an imaginary centre lying between the centre of the slot in the
quadrant and the point of suspension, thereby causing the quadrant to be shifted
bodily to one side or the other according to the direction in which it is tilted. Or
the quadrant may be guided to move vertically in a straight path and rotated or
tilted on the centre of the slot by means of a horn or bracket on the upper-side.
The radius bar by which this bracket is held in position is fixed to a point
certain distance below the horizontal line. This has the effect of causing a small
tilting motion during the up and down stroke and making the points of cut-off,
above and below the piston, to be approximately equal.
It is not requisite however to obtain the compound motion that the existing
arrangement of quadrant should be adopted, and in place of it a system of links
and levers may be employed. The end of the valve lever is pivotted to a link;
which at its other end is connected by a radius bar to an arm on the weigh shaft.
This link I will call the first link. To the first link there is pivotted a second
link, the other extremity of which is pivotted to a point at or near the end of the

page_text: eccentric rod, which is guided by a radius bar in an approximately straight line.
To obtain the compensating motion in this system the second link may be con-
nected to the eccentric rod above the point of connexion of the radius rod, or both
it and the radius rod may be pivotted at a point somewhat higher. than would be
otherwise necessary.
Referring to the accompanying sheets of drawings Fig. 1 is an elevation of a
valve gear according to this invention; Fig. 2 is a plan, Fig. 3 a vertical section
through the quadrant, and Fig. 4 a detail view. Qis a quadrant furnished with a
curved slot in which works a block connected by a lever or a system of levers l. l,
to the valve. A plan shewing the attachment of the levers to the block is given
in Fig. 4. Upon the quadrant are two horns or ears 6161 to each of which is
pivotted a radius bar d, connected at its other end to an arm b upon the weigh
shaft a. Upon this shaft there is a reversing lever b* by which it can be partially
rotated in either direction. The effect upon the quadrant of tilting it in one
direction is shewn in dotted lines. The quadrant is also guided between the two
fixed supports e, e while it receives a reciprocating motion from the eccentric f
and rod g.
It will be evident that so long as the quadrant occupies the angular position
shown in full lines the motion of the valve is derived entirely from the eccentric.
But if the quadrant be tilted the block must rise and fall as it travels to and fro in
the slot, and thus the travel of the valve will be increased. This latter motion
determines the point of cut-off. By reversing the angle of the quadrant the
engine is reversed, the lead, however, remaining constant, as the angular position
of the quadrant has little or no effect on the valve at the point when the crank
passes the centres.
In the drawing the point of suspension of the quadrant is shewn above the
centre of the slot, an arrangement which causes a slight side motion to the
quadrant when it is tilted, and in this case in which the compensating motion
comes into play the horns 61 61 are so arranged that the quadrant is moved round
an imaginary centre at O lying between the centre of the slot and point of
suspension.
Fig. 5 is an elevation of a slightly modified form of valve gear according to this
invention. Fig. is an elevation, partly in section, at right angles to Fig. 5, and
Fig. 7 is a plan partly in section. In this arrangement the quadrant Q is con-
strained to move in a straight vertical path by means of the guides H H and has
only one horn 61, the radius rod d is so disposed that as the quadrant is moved up
and down it is also tilted to a small extent. This device effects the compensating
motion and causes the points of cut-off above and below the piston to be
approximately equalised. . are the valve levers, ee the vertical guides, ƒ the
eccentric, and g the eccentric rod.
Fig. 8 is an elevation of another modification according to this invention. The
valve lever is connected to a link i, which at its opposite end is pivotted by the
radius bar d to the lever b on the weigh shaft a. This link is also pivotted by
the link to the extremity of the eccentric rod, the point of connexion being
guided in an approximately straight line by the radius bar d, which at its other
end is pivotted to a fixed point. In the position shewn in the drawing the valve
is moved solely by the eccentric the oscillation of the cylinder having no effect
on it. By partially rotating the weigh shaft in either direction the link i is
moved into such a position that a motion compounded of that of the cylinder, and
of that of the eccentric is obtained. To obtain the compensating motion the link k
is extended from q to q³, or the eccentric rod is extended from q¹ to q² (Fig. 9).
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what
I claim is :-
1. Actuating the valve (or valves) substantially as described by the conjoint.uso
of three motions namely the oscillating motion of the cylinder, a motion derived

page_text: from an eccentric or from the piston rod, and a motion the resultant of the said
two motions this third motion acting either directly or through a system of levers.
2. Obtaining an equal cut off at each end of a cylinder when the valve (or
valves) is (or are) actuated as referred to in the preceding claim, by making the
quadrant to move or tilt about an imaginary point lying between the centre of
the alot and the point of suspension, substantially as described with reference to
Figs. 1 to 3 of the drawings.
3. Obtaining an equal cut-off at each end of a cylinder when the valve (or
valves) is (or are) actuated as referred to in the first claim by so suspending the
quadrant that it has a constant slight oscillating motion substantially as described
with reference to Figs. 5 to 7 (sheet 2) of the drawings.
4. Obtaining an equal cut-off at each end of a cylinder when the valve or
valves is (or are) actuated as referred to in the first claim by guiding the eccentric
rod at a point beyond its point of attachment to the first link, substantially as
described with reference to Fig. 9 of the drawings, or by lengthening the first link
and connecting it to the eccentric rod at the point at which the latter is guided by
the radius rod, as described with reference to sheet 3 of the drawings.
5. The improved valve gear constructed arranged and operating as described
with reference respectively to and shown in Figs. 1, 2, 3 and 4, in Figs. 5, 6 and 7,
in Fig. 8, and in Fig. 9 of the drawings.
1000