Improvements in and connected with Engine-valves.
Year: 1898

page_text: Date of Application, 23rd Dec., 1898
Complete Specification Left, 22nd Sept., 1899-Accepted, 16th Dec., 1899
Improvements in and connected with Engine-valves.
1, JOHANN STUMPF, of 27, Ranke Strasse, Berlin, in the Kingdom of Prussia,
Geiman Empire, Professor, do hereby declare the nature of this invention to be
as follows
The object of the present invention 18 to provide the valve proper with a
cushion which starts to act as soon as the cut off edge has been passed, and
then acts with the greatest rapidity
Admission valves for steam engines operated by a trip motion are usually
provided with air or oil dashpots fixed above the valve to the upper part of
the valve-spindle The air dashpots generally have the disadvantage of sucking
an during the whole shoke In consequence of the throttling of the air-supply,
a partial vacuum 18 formed in the ai dashpot When the valve is released
and drops down, the action of the dashpot at starting 18 80 heavy that the valve
when coming near to the seat has lost a great deal of its speed and the valve
is consequently seated very gently
The aur dashpot must be constructed on rather a large scale as at the commence-
ment of the stroke there is a partial vacuum which in consequence produces a
gradual increase of au-pressuie
Another arrangement to obtain the necessary cushion 18 the oil dashpot
which recently came in use These oil-dashpots in comparison with the air
dashpots have the great advantage that the cushioning action only starts
at the end of the stroke whereby the cut off is effected under more
favorable cucumstances, but these oil dashpots have this great disadvantage
that, by inaccurate adjustment of the dashpot the valve being stopped by the
enclosed oil does not properly close on its seat This is the reason why valves
provided with oil dashpots are not steam tight which very often also happens
with the air dashpots.
It is also possible when air dashpots are employed that the valve proper,
owing to the compression of air, rebounds before finally becoming seated
The valve forming the object of the present invention effects a perfect cut
off, and being in the form of a piston valve provided with a number of shoulders
a very effective steam cushion is formed between the shoulders and the seatings.
Immediately after release the valve under the pressure of a spring and owing to
its own weight drops down, and passes the cut off edge with the greatest rapidity
and closes steam tight at once In passing the cut off edges a steam cushion is
formed between the shoulders of the valve and its seats, whereby the rapid
motion of the valve is checked and in consequence the valve 18 gently seated
In order to make my invention more clear, I refer to the accompanying drawing,
in which similar letters denote similar parts throughout the different views, and
in which:
Figure 1 shows a vertical section through the valve, and valve box
Figure 2 shows a section through a steam cylinder with admission and exhaust

page_text: Figure 3 shows an example of an indicator diagram shewing the gain obtained
with my valve.
In the valve casing a two valve seats are arranged The valve d, having
two pans of cut-off flanges d d 18 attached to the spindle e which spindle 18
connected m a known manner with tip gear The valve is scated by a spring f.
No explanation 18 needed as to the form of the cut off flanges of the valve or of the
valve seats, as they are clearly represented in the drawing The valve cylinder
18 bored to correspond with the shouldered or step-like form of the piston valve
so that at each pair of cut off edges two surfaces b¹ and act like a piston
valve which as soon as the corresponding edges are in contact, make a steam-
tight joint Between the upper and lower cut-off edges of cach pair of flanges
and the valve seatings 6 annulai steam cushions are formed whereby the further
gentle lowering of the valve onto its seat is effected as the steam pressure already
high at the moment the cushion is formed increases enormously during the con-
tinued motion of the valve. With such a valve a very sharp cut-off is effected
and a diagram is obtained, as shown in Figure 3, without any tendency to
throttling of the steam as indicated.
In my valve the steam space between the shoulders and the seats in conjunction
with the two piston-valve surfaces form a labyrinth steam Joint, which joint 18
further protected by the grease and condensation water. As soon as the admission
of steam has been cut off, a powerful cushioning action commences, the steam
at a pressure of 6, 8 or 10 atm as the case may be boing now enclosed and com-
pressed The powerful cushioning action is a result of the rapid raising of the
pressure in respect to the high pressure at the moment the steam was enclosed.
No transmission of the cushioning power by means of spindle- or sciew-connections
is needed The regulation of the cushion can be effected by a suitable arrange-
ment vaiving the pressure in the annular cushion chamber. In Figure 1 of the
drawing the two cushion chambers are connected by a channel k which also
opens into the valve casing The outlet opening is regulated by an outside
BC1 ew Evidently the channel & may conduct into the steam chamber above the
valve or into the open air The valve being readily seated, a steam-tight joint
made by the valve seat is added to the steam joint made by the piston valve
surfaces, so that together with the labyrinth joint a third joint is in action
arrangement evidently can be used in combination with valves having single
steam ports and it is possible, to increase the number of seats and shoulders
in order to obtain still better joint
Dated this 23rd day of December 1898
This
COMPLETE SPECIFICATION
Improvements in and connected with Engine-valves.
1, JOHANN STUMPF, of 27, Ranke Strasse, Berlin, in the Kingdom of Prussia,
German Empue, Professor of Engineering, 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-
-
The object of the present invention is to provide the valve proper with a
oushion which starts to act as soon as the cut-off edge has been passed, and
then acts with the greatest rapidity
Admission valves for steam engines operated by a trip motion are usually
provided with an or oil dashpots fixed above the valve to the upper part of

page_text: the valve-spindle The air dashpots generally have the disadvantage of sucking
air during the whole stroke In consequence of the throttling of the air-supply,
a partial vacuum is formed in the air dashpot When the valve 18 released
and drops down, the action of the dashpot at starting is so heavy that the valve
when coming near to the seat has lost a great deal of its speed and the valve
is consequently seated very gently
The an dashpot must be constructed on rather a large scale as at the commence-
ment of the stroke there is a partial vacuum which in consequence produces a
gradual increase of air pressure.
Another arrangement to obtain the necessary cushion is the oil dashpot
which recently came into use These oil-dashpots in comparison with the air
dashpots have the great advantage that the oushioning action only starts
at the end of the stroke whereby the cut-off 18 effected under more
favorable circumstances, but these oil dashpots have this great disadvantage
that by inaccurate adjustment of the dashpot the valve being stopped by the
enclosed oil does not properly close on its seat This is the reason why valves
provided with oil dashpots are not steam tight which very often also happens
with the aur dashpots.
It is also possible when air dashpots are employed that the valve proper,
owing to the compression of an, rebounds before finally becoming seated
The valve forming the object of the present invention effects a perfect cut-
off and being in the form of a piston valve provided with a number of shoulders
a very effective steam cushion 18 formed between the shoulders and the seatings
Immediately after release, the valve under the pressure of a spring and owing to
its own weight, drops down, and passes the cut-off edge with the greatest rapidity
and closes steam tight at once In passing the cut-off edges a steam cushion is
formed between the shoulders of the valve and its seats, comes into action whereby
the rapid motion of the valve 18 checked and in consequence the valve 18 gently
Beated.
In order to make my invention more clear, I refer to the drawings accompanying
the Provisional Specification, in which similar letters denote similar parts through-
out the different views, and in which.
Figure 1 shows a vertical section through the valve and valve box.
Figure 2 shows a section through a steam cylinder with admission and exhaust
valves
Figure 3 shows an example of an indicator diagram showing the gain obtained
with my valve
In the valve casing a the two valve seats b are arranged The valve d having
two pairs of cut-off flanges d d 18 attached to the spindle &, which spindle 18
connected in a known manner with trip gear The valve is seated by a spring f
No explanation is needed as to the form of the cut-off flanges of the valve and of the
valve seats, as they are clearly represented in the drawing The valve casing
18 bored to correspond with the shouldered or step-like form of the piston valve
so that at each pair of cut edges two surfaces and act like a piston
valve which, as soon as the corresponding edges are in contact, make a steam-
tight joint Between the upper and lower cut-off edges of each pair of flanges
and the valve seatings 6 annular steam cushions are formed whereby the further
gentle lowering of the valve on to its seat is effected, as the steam pressure alieady
high at the moment the cushion is formed increases enormously during the con-
tinued motion of the valve With such a valve a very sharp cut-off is effected
and a diagram obtained, as shown in Figure 3, without any tendency to
throttling of the steam as indicated
In my valve the steam spaces between the shoulders and the seats in conjunction
with the two piston valve surfaces form a maze steam joint, which joint is
further protected by the grease and condensation water As soon as the admission
of steam has been cut-off, a powerful cushioning action commences, the steam
at a pressure of 6, 8-10 atm being now enclosed and compressed
The

page_text: powerful cushioning action is a result of the rapid raising of the pressure
with respect to the high pressure at the moment the steam was enclosed No
transmission of the cushioning power by means of spindle- o sciew-connections
18 needed. The regulation of the cushion can be attained by a suitable airange-
ment varying the pressure in the annular cushion chambei In Figure 1 of the
drawing the two cushion chambers are connected by a channel which also
opens into the valve casing The outlet opening is regulated by an outside
sciow Evidently the channel & may lead into the steam chamber above the
valve or into the open an The valve being seated, a steam tight joint made by
the valve seat is added to the steam joints made by the piston valve surfaces
This arrangement evidently can be used in combination with valves having single
steam ports and it is possible, to increase the number of seats and shoulders
in order to obtain a still better joint
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
-
1. Providing a tup valve on valve of similar type with a flange or flanges for
cutting off the steam before the valve seats itself and with a cushion or several
cushions formed between the valve and its casing substantially as and for the
purpose set forth
2 The construction of valve substantially as described and shown in the draw-
ings