IMPROVEMENTS IN OR RELATING. TO VALVES FOR DOUBLE ACTING ENGINES
Year: 1885

page_text: I, JOHANNES FRANCISCUS MEYJES Engineer, of Zweibrücken, Bavaria, Gerinan
Empire do hereby declare the nature of my invention for "IMPROVEMENTS IN
OR RELATING. TO VALVES FOR DOUBLE ACTING ENGINES to be as follows:-
>>
This invention relates to a rotary valve for steam engines working at high
speeds in which an expansion cap, governed by the governor of the engine, is
employed for regulating the cut off.
The plug or valve has two inlet passages and two exhaust passages it rotates in
a fixed shell or casing the apertures wherein are placed alternately, and the number
of rotations of the plug is just half that of the crank shaft; the rotation of the
plug causes the distribution of the steam while the expansion or cut off cap
determines the amount of steain supplied.
The hollow interior of the plug is by suitable partitions divided into four com-
partments and has two apertures establishing cominuni ation between the steam
supply and the inlet ports of the engine through four slits or apertures in the
expansion or cut off cap.
Two other apertures in the plug connect the engine with the exhaust pipe.
The plug or valve always rotates in the same direction and works in a box or
chamber provided in the valve casing and having two apertures placed diametrically
facing one another for the supply and exhaust of the rear portion and two similar
apertures for the front part. The expansion or cut-off cap rotates under the
influence of the governor and has four slots or apertures. The plug or valve is
driven by a small shaft or spindle off the crank shaft; the expansion or cut-off cap
receives motion by means of a link and lever arrangement connecting it with the
governor.
The rotation of the expansion cap in one or the other direction determines the
extent to which the steam inlets are opened.

page_text: "
Engines.
I JOHANNES FRANCISCUS MEYJES, Engineer of Zweibrücken, Bavaria, German
Empire 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 relates to improvements in valve gear for double acting engines
and consists essentially in a rotary valve for steam engines working at high speed,
in which an expansion cap, governed by the governor of the engine is employed
for regulating the cut-off.
The plug or valve has two inlet and two exhaust passages, it rotates in a fixed
shell or casing, the apertures wherein are placed alternately, and the number of
revolutions of the plug is just half that of the crank-shaft; the revolution of the
plug causes the distribution of the steam, while the expansion or cut-off cap
determines the supply of the steam.
In the accompanying drawings Figure 1 represents a longitudinal section of the
cylinder and valve at the moment when the piston is at the dead point at the back
Figure 2 the same when the piston is at the dead point in front.
The other Figures represent different sections and details.
The hollow interior of the plug S is divided into four compartments by oblique
partitions (see Figures 3 to 5) and is provided with two inlet aperatures e establishing
communication between the steam supply and the inlet ports of the engine through
four slits i in the expansion or cut-off cap E (see Figures 1. 2 and 8).. Two other
slits or apertures a in the plug connect the engine with the exhaust-pipe.
The plug or valve S always rotates in the same direction and works in a box or
chamber B provided in the valve casing and having two apertures 1 and 2,
Figures 1 and 3 placed diametrically facing each other for the supply and exhaust
of the rear part and two similar apertures 3 and 4, Figures 1 and 5 for the front
part. The expansion or cut off cap E rotates under the influence of the governor
and has four slots or apertures i, Figures 1, 2 and 8. The plug or valve S is driven
by a small shaft or spindle w off the crank shaft, the expansion or cut off cap E
receives motion by means of a link and lever arrangements and h connecting it
with the governor.
The rotation of the expansion cap E in one or the other direction determines the
extent to which the steam inlets are opened, for instance in the position as
represented in Figure 8 no supply and as represented in Figure 8a a full supply
takes place.
If the piston stands at the dead point in the rear part, Figure 1 the steam will
enter through the slots i into the valve S and the inlet apertures e. The steam can
however only enter the passage k¹ through the open slots 1 and 2. of the casing B,
to drive the piston from back to front (Figure 3 being a section on line II II).
At the same time the exhaust steam escapes through the passage * and the slots 3
and 4 of the casing B (Figure 5) into the valve and through the apertures o into
the exhaust pipe A.

page_text: When the piston next stands at the dead point in front, the crankshaft has made
a turo of 180° while the spindle w has only made a turn of 90° (Figure 2). The
relative position of the valve and the casing in this case is such that the fresh
steam will enter through the slots e of the valve and the slots 3 and 4 of the casing
into the passage while the exhaust steam escapes through the passage k¹ the
slots 1 and 2 of the casing and apertures a into the exhaust pipe A.
The rotating valve therefore regulates the supply as well as the exhaust of the
steam without special passages in the cylinder or valve-casing.
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
Iclaim is
1. In a valve gear for double acting engines a valve such as S rotating at half
the speed of the crankshaft in a casing such as B and having two inlet passages a
and two outlet passages a substantially as and for the purpose specified.
2. In a valve gear for double acting engines the arrangement of an expansion
cap E connected with the adjusting gear of the governor so as to regulate the
cut-off of such valve, substantially as specified.