Improvements in Steam or Fluid Pressure Engines.
Year: 1884

page_text: Improvements in Steam or Fluid Pressure Engines.
I, DAVID JOY, of 8 Victoria Chambers Westminster, Engineer, do hereby declare
the nature of said Invention for "IMPROVEMENTS IN STEAM OR FLUID PRESSURE
ENGINES" to be as follows:-
This Invention has for its object the simplification of the valve motions of
engines having two or more cylinders and is especially suited for marine engines
but is also applicable to steam or fluid-pressure engines generally.
The said Invention consists in obtaining the motion for the valves from the
combination of the motions of the air pump lovers, or levers similarly oporated.
The said Invention as applied to two cylinder engines consists in taking the
motion for the valve of each cylinder partly from its own air pump lover (or a
lever similarly moved) and partly from the air pump lever of the second cylinder
(or a lever similarly moved) thus obtaining the direct and transverse motions
which combined give the required action to the valves.
As applied to three cylinder engines I employ the air pump levers (or levers
similarly moved) of any two of the cylinders to give by combination a movement
suitable for operating the valve of the remaining cylinder, and so in turn for the
valves of each of the two first mentioned cylinders I combine the motions of the
levers operated by the other two.
I do not limit myself to any particular details of mechanism for combining the
motions, as the said mechanism may be of any suitable description.
I include in the expressions two and three cylinder engines any duplicate or
multiple arrangement of such cylinders.

page_text: Improvements in Steam or Fluid Pressure Engines.
I, DAVID JOY of 8 Victoria Chambers Westminster Engineer do hereby declare
the nature of my invention for "IMPROVEMENTS IN STEAM OR FLUID PRESSURE
ENGINES" and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
This Invention which has for its object the simplification of the valve motions
of engines having two or more cylinders is especially suited for marine engines
but is also applicable to steam or fluid pressure engines generally-It consists in
obtaining the motion for the valves from the combination of the motions, of the
air pump levers or levers similarly operated. The said Invention as applied to
two cylinder engines consists in taking the motion for the valve of each cylinder
partly from its own air pump lever (or a lever similarly moved) and partly from
the air pump lever of the second cylinder (or a lever similarly moved) thus
obtaining the direct and transverse motions which combined, give the required
action to the valves-As applied to three-cylinder engines I employ the air pump
levers (or levers similarly moved) of any two of the cylinders to give by com-
bination a movement suitable for operating the valve of the remaining cylinder,
and so in turn for the valves of each of the two first mentioned cylinders,
I combine the motions of the levers operated by the other two.
I do not limit myself to any particular details of mechanism for combining the
motions as the said mechanism may be of any suitable description-I include
in the expressions two and three cylinder engines any duplicate or multiple.
arrangement of such cylinders.
Figure 1 represents diagrammatically my motion as applied to two cylinder
engines with their cranks set at or about right angles-The full lines represent
the nearer engine and the dot and pick lines the further one-Here the air pump
lever A of the nearer engine centred at A¹ carries a quadrant B centred on it at B¹
where its motion is equal to the "laps and leads" required for the valve and thus
that part of the motion of the valve is provided, and this corresponds to the
reciprocating movement of the connecting rod and piston rod-The remainder
of the movement required for port opening is provided from the motion of the air
pump lever of the other engine shown in dot and pick lines at L; this motion is
transmitted through the vertical lever I (keyed on the shaft of the lever L) to
the head of the quadrant B linked at c, c¹ thus the quadrant B is rocked on its
centre B¹ and this motion takes place at a time corresponding to the vibration of
the connecting rod, and so is correct for port opening, and it is controlled as to
amount, or for reversal, by the position at which the valve spindle link D is set
in the curve of the quadrant B, the full line D representing it in position for
forward gear, and the dotted line D¹ in position for backward gear, any inter-
mediate position being for expansion.
Figure 2 represents diagrammatically my Invention as applied to three cylinder
engines with their cranks set at or about 120° apart, here the full lines represent
the nearer engine 1, the plain dotted lines the next engine 2 and the dot and pick

page_text: lines the further engine 3-Here, as any two cranks are in the position relatively
to the third, that it would be necessary to set the excentrics to work a link motion
for that crank, it is only necessary to provide a valve motion for the nearer
cylinder and crank, to mount a quadrant link B with its one end B¹ carried by the
air pump lever A of the second engine, and its other end B carried by the air
pump (or other similar lever) L of the further engine 3, the points on each of
these levers being chosen to give the required motion for the valve, the valve
spindle link D which is shown in full lines in the middle position is moved
towards either end of the quadrant to D¹ or D2 to give forward or backward
motion-The other two engines are similarly treated, but to avoid confusion the
quadrants are not drawn in.
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
In steam and other fluid pressure engines obtaining the motion for the valves
by the combination of the motions of the air pump levers, or levers similarly
operated, substantially as hercinbefore described and also the particular arrange-
ments for the purpose illustrated in the accompanying drawings.