IMPROVEMENTS IN WORKING SLIDE VALVES BY STEAM PRESSURE. ANd Apparatus THEREFOR.”
Year: 1873

page_text: LETTERS PATENT to Heinrich Adolf Hülsenberg, of Tynemouth
Terrace, Victoria Park, in the County of Middlesex, for the
Invention of "IMPROVEMENTS IN WORKING SLIDE VALVES BY STEAM
PRESSURE. ANd Apparatus THEREFOR.”
"
PROVISIONAL SPECIFICATION left by the said Heinrich Adolf
Hülsenberg at the Office of the Commissioners of Patents, with his
Petition, on the 21st April 1873.
I, HEINRICH ADOLF HÜLSENBERG, of Tynemouth Terrace, Victoria
Park, in the County of Middlesex, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN WORKING SLIDE VALVES BY STEAM
PRESSURE, AND APPARATUS THEREFOR," to be as follows:-
:-
This Invention relates to improvements in the working of the slides
or valves of steam cylinders by means of pistons or plungers acted on by
steam pressure, as the main piston approaches either end of its stroke.
For this purpose, I attach the slide to a plunger fitted to work in

page_text: cylindrical cavities at each end of the slide jacket, and I provide
supplementary ports communicating from these cavities to the main
cylinder, opening into the latter at some distance from each end thereof.
As the main piston approaches one end of its stroke it uncovers one of
these ports, and allows steam to flow from the cylinder to act on one
end of the plunger in the slide jacket, and thereby to move the slide so
as to alter the steam passages to the cylinder, and at the same time to
cut off the steam from the slide plunger. As the main piston approaches
the other end of its stroke it in like manner uncovers the other com-
municating port, whereby the slide is moved back in a similar manner.
There are several known contrivances whereby an action similar in some
respects to that above described is produced by the pressure of steam
admitted from the main cylinder by ports uncovered by the main piston;
but according to most of these contrivances the plungers or pistons
which actuate the slide are exposed throughout their full stroke to the
pressure which moves them, and they are thus caused to move suddenly
and to be stopped abruptly at the end of their stroke.
The object of my Invention is to avoid such sudden and abrupt
movements, and for this purpose I cause the movement of the slide
plunger itself to close the port supplying steam for its movement when
it has performed only a portion of its stroke, the residue of the stroke
being effected by the expansion of the steam already admitted.
One mode in which I effect this is the following:-I bore into the end
of the main plunger which moves the slide a cylindrical hole, into which
projects a fixed tubular plunger communicating with the supplementary
port from the cylinder. The end of this tubular plunger is closed, but
there are lateral openings near its end. The hole in the main plunger
has also lateral holes communicating with the cavity in which it works.
When the holes in the tubular plunger are facing the holes in the main
plunger, steam from the main cylinder can freely pass into the cavity
and act upon the main plunger so as to move it; but when by its
movement it covers the holes of the tubular plunger this steam supply
is cut off, and the rest of its movement is effected by the expansion of
the steam already admitted, and therefore with a diminishing pressure,
whereby its movement and stoppage are rendered gentle and free from
shocks. While the plunger is thus being moved in one direction by the
pressure at one end of it, the cavity at the other end of it communicates
by similar holes to those above described with a central cavity which is

page_text: permanently in communication with the exhaust port of the slide; and
when the plunger at either end has moved almost to the end of its
stroke, its holes come into communication with this exhaust cavity, and
remain so till the plunger is moved back, as already described.
According to another modification I bore a longitudinal hole through
the main plunger which moves the slide, and I fit into this hole a
tubular plunger which projects some distance at either end. In this
tubular plunger there are lateral holes, and there are corresponding
lateral holes in the main plunger. By these holes, when they face each
other, passage is afforded for steam to press on one end of the main
plunger, and for steam to escape from the other end to the exhaust
port; but when the main plunger carrying with it the aforesaid tubular
plunger approaches the end of its stroke the projecting end of the latter
meeting the end of the slide jacket is relatively moved within the main
plunger, so as to cut off the steam communication and to leave the
residue of the stroke of the plunger to be effected by the expansion of
the steam already supplied.
The arrangements above described are applicable to the movement of
a slide fitted at the side of a cylinder and moved in both directions by
the pressure of steam from the cylinder.
I will now describe a construction whereby a slide fitted at the end of
a cylinder is moved in the one direction by the main piston bearing
against it or a projection from it as it approaches the near end of its
stroke, and is moved in the opposite direction by the pressure of steam
admitted from the main cylinder by a supplementary port uncovered by
the main piston as it approaches the farther end of its stroke. In this
case the slide is made of cylindrical form to work as a plunger in a
cavity formed in the end cover of the cylinder. The front part of this
plunger which is presented towards the main piston is of smaller
) diameter than the back part, and the cavity in which it works is made
of different diameters at front and back to suit those of the plunger:
Thus the plunger when subjected to the same pressure at front and back
will move forwards in obedience to the excess of pressure on the larger
area. This plunger either has lateral passages arranged in connection
5 with steam ports so as to constitute a slide in itself, or is connected to a
slide so as to work the same with it. When the piston approaches the
near end of the cylinder it meets the end of the plunger or a projection

page_text: from it and pushes it back, so as to alter the steam passages and reverse
the movement of the piston. As the piston approaches the farther end
of its stroke it uncovers a supplementary port communicating with the
back of the cavity in which the plunger works. The plunger being
thus exposed to equal pressure at front and back moves forward in
obedience to the excess of pressure on its larger area, as already set
forth. The slide passages being thus altered the movement of the piston
is reversed, and this action is repeated for every successive stroke.
filed by the said Heinrich Adolf Hülsenberg in the Great Seal Patent
Office on the 20th October 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HEINRICH
ADOLF HÜLSENBERG, of Tynemouth Terrace, Victoria Park, in the County
of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of April, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Heinrich Adolf Hülsenberg, Her special
license that I, the said Heinrich Adolf Hülsenberg, my executors, admin-
istrators, and assigns, or such others as I, the said Heinrich Adolf
Hülsenberg, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN WORKING SLIDE VALVES BY STEAM PRESSURE, AND Apparatus
THEREFOR," upon the condition (amongst others) that I, the said Heinrich
Adolf Hülsenberg, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-
ticularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Heinrich Adolf Hülsenberg, do
hereby declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, reference being had to the
accompanying Sheets of Drawings, and to the figures and letters marked
thercon, that is to say:―
This Invention relates to improvements in the working of the slides
or valves of steam cylinders by means of pistons or plungers acted on
by steam pressure as the main piston approaches either end of its stroke.
For this purpose I attach the slide to a plunger fitted to work in
cylindrical cavities at each end of the slide jacket, and I provide supple-
mentary ports communicating from these cavities to the main cylinder,
opening into the latter at some distance from each other thereof. As the
main piston approaches one end of its stroke it uncovers one of the
ports and allows steam to flow from the cylinder to act on one end of
the plunger in the slide jacket, and thereby to move the slide so as to
alter the steam passages to the cylinder, and at the same time to cut off
the steam from the slide plunger. As the main piston approaches the
other end of its stroke it in like manner uncovers the other communi-
cating port, whereby the slide is moved back in a similar manner. There
are several known contrivances whereby an action similar in some
respects to that above described is produced by the pressure of steam
admitted from the main cylinder by ports uncovered by the main piston.
But according to most of these contrivances the plungers or pistons
which actuate the slide are exposed throughout their full stroke to the
pressure which moves them, and they are thus caused to move suddenly
and to be stopped abruptly at the end of their stroke.
The object of my Invention is to avoid such sudden and abrupt move-
ments, and for this purpose I cause the movement of the slide plunger
itself to close the port supplying steam for its movement when it has
performed only a portion of its stroke, the residue of the stroke being
effected by the expansion of the steam already admitted.
One mode in which I effect this is the following:-I bore into the
end of the main plunger which moves the slide a cylindrical hole into
which projects a fixed tubular plunger communicating with the supple-
mentary port from the cylinder. The end of this tubular plunger is
closed, but there are lateral openings near its end. The hole in the

page_text: main plunger has also lateral holes communicating with the cavity in
which it works. When the holes in the tubular plunger are facing the
holes in the main plunger steam from the main cylinder can freely pass
into the cavity and act upon the main plunger so as to move it. But
when by its movement it covers the holes of the tubular plunger this
steam supply is cut off, and the rest of its movement is effected by the
expansion of the steam already admitted, and therefore with a diminishing
pressure, whereby its movement and stoppage are rendered gentle and
free from shocks. While the plunger is thus being moved in one
direction by the pressure at one end of it the cavity at the other end of 1
it communicates by similar holes to those above described with a central
cavity which is permanently in communication with the exhaust port of
the slide. And when the plunger at either end has moved almost to the
end of its stroke its holes come into communication with this exhaust
cavity, and remain so till the plunger is moved back as already
described.
According to another modification I bore a longitudinal hole through
the main plunger which moves the slide, and I fit into this hole a
tubular plunger which projects some distance at cither end. In this
tubular plunger there are lateral holes, and there are corresponding
lateral holes in the main plunger. By these holes, when they face each
other, passage is afforded for steam to press on one end of the main
plunger and for steam to escape from the other end to the exhaust port.
But when the main plunger, carrying with it the aforesaid tubular
plunger, approaches the end of its stroke, the projecting end of the latter
meeting the end of the slide jacket is relatively moved within the main
plunger so as to cut off the steam communication and to leave the
residue of the stroke of the plunger to be effected by the expansion of
the steam already supplied.
The arrangements above described are applicable to the movement of
a slide fitted at the side of a cylinder and moved in both directions by
the pressure of steam from the cylinder.
I will now describe a construction whereby a slide fitted at the end of
a cylinder is moved in one direction by the main piston bearing against
it or a projection from it as it approaches the near end of its stroke, and
is moved in the opposite direction by the pressure of steam admitted
from the main cylinder by a supplementary port uncovered by the main

page_text: piston as it approaches the farther end of its stroke. In this case the
slide is made of cylindrical form to work as a plunger in a cavity formed
in the end cover of the cylinder. The front part of this plunger which
is presented towards the main piston is of smaller diameter than the
back part, and the cavity in which it works is made of different diameters
at front and back to suit those of the plunger. Thus the plunger when
subjected to the same pressure at front and back will move forwards in
obedience to the excess of pressure in the larger area. This plunger
cither has lateral passages arranged in connection with steam ports so as
to constitute a slide in itself, or is connected to a slide so as to work tho
same with it. When the piston approaches the near end of the cylinder
it meets the end of the plunger or a projection from it, and pushes it
back so as to alter the steam passages and reverse the movement of the
piston. As the piston approaches the further end of its stroke it un-
covers a supplementary port communicating with the back of the cavity
in which the plunger works. The plunger being thus exposed to equal
pressure at front and back moves forwards in obedience to the excess of
pressure on its larger area, as already set forth. The slide passages being
thus altered the movement of the piston is reversed, and this action is
repeated for every successive stroke.

page_text: The action of the slide is as follows:-Steam is passing the port 1
into the cylinder, and the main piston is moving from the left to the
right towards the auxiliary steam hole E³. In the meantime the back
or right hand end of the piston and of the plunger A is in communica-
tion with the exhaust; the piston moves onwards over the hole E³, which
on approaching its extreme position to the right, it uncovers. Steam
then flows through holes E², E, 63, 6³, and c³, c³, into the cavity O¹, and
the other end O of the plunger being in connection with the exhaust M,
the plunger is moved from the right to the left with the full pressure of
steam until c² passes the corner 6s of the hole in the tubular plunger B³.
Thus the plunger A is moved with full steam for only one portion of its
stroke, the residue of the stroke being performed by the expansion of
the steam already admitted behind it.
In order to ensure that during the movement of the plunger A. from
the right towards the left, the left end of the plunger may not be
subjected to new steam entering O, the different holes in the plunger A
and the tubular plungers B' and B³, are so arranged as to bring the
cavity O into communication with the exhaust, when the corner c of the
plunger A hole comes opposite to the corner 6' of the tubular plunger B¹,
the slide having travelled so far to the left as to open the left end of
cylinder to the exhaust. The motion of the plunger A is altogether
stopped when the corner e³ of the lateral hole L' has passed the end f'
of the tubular plunger B³, the expanded steam which was cnclosed in
the cavity O¹ being thus suddenly released. Thus the plunger A. moves
from the right to the left with a gradually slackening speed, in pro-
portion as the pressure of steam acting in the cavity O¹ decreases,
and the motion of this plunger is at the end of its stroke stopped
altogether. The movement in the opposite direction is performed in a
similar manner.
At starting should the plunger A be in its middle position (as shewn
in Fig. 4) it can be started by the hand lever K³, or in the manner
which I will now describe, referring to Figs. 4, 5, 6, and 7, Sheet I. On
the side of the chest H are two small ports k, l, and k², k³, which are
connected by a small cock P, having an axial hole P³, and two small
cross holes ; P¹ is a small steam hole leading to the seating of the cock P.
On moving the lever D', which is fixed to the cock to the position D'
(Fig. 6), the right side of the plunger A is put in communication with
the steam, consequently the plunger is moved to the left until the

page_text: motion is arrested, as at the end of its stroke the cavity Is put in
communication with the exhaust in the manner above described. The
lever D¹ being brought into the position D³, the slide is moved in the
opposite direction, and neitner end of the plunger is in communication
with the steam by means of the cock P, when the lever is in its middle
position D².
To prevent the plunger being driven over by the full pressure of steam
the lever D¹ should be quickly brought back to its middle position.
In applying my Invention to steam cylinders working expansively I
combine with a slide, as above described, an expansion slide operating
in a similar manner, as I will now describe in reference to Figs. 8, 9,
10, 11, 12, 13, 14, and 15, Sheet I. At the side of the slide chest H I
arrange a cylindrical cavity H°, in which works the expansion slide V,
this slide being placed in the course of the steam inlet F°, F. It has a
construction similar to that of the plunger described above, and likewise
slides upon a tubular plunger R³.
E (Fig. 13) is a small cock containining a piston disc X and
connecting two steam ports / and ', which communicate with the ends
O and O¹ of the slide chest; a small hole 3 leads from the cock Ex to
the front cavity S of the expansion valve chamber. A similar cock P°
connects two auxiliary steam ports U, Q, and U¹, Q', running along the
side of the main steam cylinder and opening by holes U and U¹ at a
certain distance from the respective ends of the steam cylinder.
The cock P° (Figs. 12 and 14) has on its bottom a hole R opening to
the bottom of the cavity in which the cock works, and this cavity is
through R, R³, R², and R³, and the valve V at certain times
in communication with the back end S₁ of the expansion valve
chamber. T, T°, is an exhaust port leading to the common exhaust G.
By this expansion apparatus the steam cylinder can be worked with or
without expansion at pleasure. Suppose it is intended to work with
expansion, and the valve V to be in the position shown in Fig. 8, the
main piston moving from right to left, the action of the expansion
apparatus is as follows:-When the main piston has moved so far to the
left as to uncover the hole U¹ steam will rush through Q1, the cock P°,
through R, R¹, R³, R³, into the cavity S³, and will throw the valve V to
the position shown in Fig. 10. The steam is then cut off from the

page_text: steam chest H, in consequence of which the main piston will perform
the rest of its stroke by the expansion of the steam already admitted.
While the steam is flowing through the cock P° the valve W is thrown
to the left, as shown in Fig. 14, thus preventing steam from passing
from one port to the other. The valve V on arriving at its end position
uncovers the hole T°, and thus the back of the valve V or the cavity S¹
is put in communication with the exhaust.
'
The motion of the
The piston on approaching now its extreme position to the left
uncovers the hole E, and steam will flow into the cavity O, and besides
driving the plunger A from the left to the right in the manner already
described will in passing through the port h move the valve X in the
cock E to the position shown in Fig. 13, and through the hole ³
(Fig. 13) will fill the cavity S and move the expansion valve V over to
the right, as indicated in Fig. 8, thus again opening the steam inlet
F, F, to the slide valve chest H. The valve X in the cock valve Ex
prevents steam flowing from h to h³, and vice versa.
piston being now reversed it will travel with full steam until it passes
the port U; then the valve W will instantaneously be thrown to the
right and the steam will pass through R, R1, R2, R3, and the valve V
into the cavity S¹, so that the valve V will be again brought into the
position shewn in Fig. 10, shutting off the steam as already described.
By turning the cock P° a little the opening of the ports Q and Q¹ can
be varied, and consequently the flow of steam through these passages,
thus varying the time that elapses before the cavity S¹ is filled to such
extent as to throw the valve V over to its opposite position, and thus
a simple turn of the cock P° produces variable expansion as desired.
Fig. 15 represents an enlarged scale cross section through the cock P°
on line of a³. Two small holes a² and a³ are made in the cock P° and a
port a, a, leads from the steam inlet F° (Fig. 14) to the cavity S;
another small port brings through e², es, the back of the cock P° and
therefore the cavity S¹ in communication with the open air, or the
exhaust if preferred. By means of these ports the expansion valve V
is held in the position shown in Fig. 8, allowing the main piston to be
worked with full steam during its whole stroke or without expansion.
By turning the cock P° so far as to bring a³ in line with the steam
port a, a, and the port a² in line with the exhaust port e, e³, steam can
flow direct from the steam inlet F° to the front cavity S and put the
back of the expansion chamber S¹ in communication with the exhaust.

page_text: By simply shifting the cock P° back to the position indicated in Figs.
14 and 15 the engine is again worked expansively.
In some cases it might be required to work the plunger A with full
steam almost up to its full stroke. For this purpose I employ two
modifications of the above described arrangement, one shown in Figs. 2
and 2 and the other in Fig. 4°; Fig. 2 shows the left-hand cavity O
and Fig. 2 the right-hand cavity O¹ of Fig. 1.
Suppose the plunger to be in its extreme position to the right, then
the small valve N¹, by virtue of its differential area, will be in the
position shown in Fig. 2ª as soon as steam begins to ascend through
the auxiliary port E and fills the cavity O', thus putting the cavity O,
by means of the small holes h³ and *, in communication with the steam
of the steam chest; in the meantime the other valve N will be kept in
the position shown in Fig. 2, because the steam presses on its annular
area h¹, and thus no fresh steam can flow into the cavity O. i and ¹ are
in communication with the exhaust.
The second modification is shown in Fig. 4. Within the plunger A.
is a second side plunger N°, N¹, à little longer than the plunger A, so as
to project at both ends, as shown in Fig. 4°. This plunger may be called
the feed slide. It has a slot cut in its centre, into which projects the
top of the slide C, and it has on its end two lateral holes n, n³, and n², n³,
Steam enters
which correspond respectively with small holes and r¹.
the right hand auxiliary port, and the plunger A is consequently driven
from the right to the left, but at the same time steam pressure, acting
upon the right hand end of the feed slide plunger N°; N¹, and the
opposite end being exposed to exhaust, the plunger N°, N¹, is driven to
the left, thus opening the steam inlet n², n³, to the cavity O', which
cavity will be supplied with steam until the left end of the slide N°, N¹,
meets the chest cover. But as the main plunger A approaches the end
of its stroke the feed slide N°, N³, will be gradually moved inward again,
thus cutting off the steam from the inlet n², n³; thereafter the main
plunger A will be moved to the end of its stroke by expansive steam
until the cavity O' exhausts, as already described.
Figs. 16 and 17, Sheet II., show how a steam cylinder with my
improved valve arrangement may be combined with a pump so as to
not without fly whool crank eccentric levers, or tannets.

page_text: Figs. 18, 19, 20, and 21, Sheet II., show another modification of my
valve arrangement. In this modification the plunger A has at each end
a cylindrical projection A³, A³, and has a central cylindrical hole, in
which slides a second hollow plunger R*, which may be termed the
regulating valve. This regulating valve is either longer than the main
plunger, as shewn at K, or may meet a projection from, the cover, as
at K³, so that when approaching either end of the cover it is shifted
back relatively to A. This regulating valve has a piston collar 7 on its
left hand, the other end 1 is simply enlarged, so that when the regu-
lating valve moves to the left its annular face cushions. The slide has
on its upper face a cylindrical projection fitting in the plunger A, and
through it passes freely the regulating valve, with an orifice com-
municating with the exhaust.
Suppose the main piston is approaching its extreme right hand
position, and is just uncovering the right hand auxiliary steam port, the
plunger and regulating valve being in the position shewn in Fig. 18,
then steam will flow through B³, and acting against the end of the
regulating valve will move it to the left, thus uncovering the steam
ports i, i, in the main plunger A, and putting the cavity O in com-
munication with the exhaust through the holes and ports c, b, R³, e,
and f, as shewn in Fig. 19. Steam pressure being thus brought to
bear upon the O' end of the plunger A, it will move to the left, but
before the plunger A has finished its stroke the regulating valve R³, R*,
will be shifted relatively to the right by its end K bearing against the
cover so as to take the position shewn in Fig. 20. The main piston will
now begin its return stroke, and when approaching its left hand extreme
will uncover the left auxiliary port. Steam will then flow through B, c,
and a, and the end of the regulating valve being of larger area than
the other end, the regulating valve will be moved towards the right,
bringing the passage 6 opposite to d; in the meantime e is closed from
the exhaust, but the cavity O' being brought into communication with
the exhaust through the holes and passages i, S, R, and g, the
plunger A will move to the right, carrying the regulating valve with it.
Before however the main plunger A has finished its stroke the regu-
lating valve will touch the projection K', so that when the plunger has
finished its stroke the regulating valve will be again in the position
indicated in Fig. 18, when the action before described is repeated. The
plunger A in approaching either end of its stroke provides its own steam
b

page_text: cushion, as the exhaust is thus cut off a short time before the plunger
completes its stroke. The swell of the regulating valve at 1 is provided
with a small hole for the passage of the steam on which it cushions.
The construction where a slide is fitted at the end of a cylinder is
shown in Figs. 22 to 27, Sheet II. A is a cylindrical slide, which at its
front is of larger diameter than at the back or end towards the steam
cylinder, and which is bored to receive a plunger R*; B is the steam
piston, and B' the pump plunger; C, K, is a starting apparatus, which
can be dispensed with when the cylinder stands vertically with its slide
downwards; F°, F¹, is the steam inlet, and Gan annular exhaust port,
having outlet G; E, E°, E, is an auxiliary steam port, and 1, 2, the
steam port for the back of the piston.
Suppose now the piston and valve to be in the position shewn in
Figs. 22 and 23, then the steam will pass through Fº, F¹, to the front of
the piston, the back of the latter being open to the exhaust through 1, 2,
L, L, and G. The piston will move till it passes the hole E¹, steam will
then flow through E¹, E°, E³, to the front of the valve, and acting on its
larger area will move it to the position indicated in Fig. 24. Steam will
then pass through Fº, F, L, L³, M³, M, and 1, 2, to the back of the
piston, and the front of the piston being open to the exhaust through G°
and G, the piston will move to the left, until it touches R* end and
moves it to the position shown in Fig. 27, thus placing the front of the
valve A in communication with the exhaust, while its other end is
subjected to the full steam pressure, whereby it will be moved again to
the position shown in Fig. 22, so as to reverse the movement of the steam
piston.
In order to start the valve for any position of the piston the slide R*
should be in its front position. To ascertain this the spindle K is pushed
inwards, and to move the slide it is slightly twisted. The inner part C
being a little eccentric, the twist gives a hold by which the slide R* can
be drawn to the required position. It will be seen that according to this
arrangement, in order to move the slide only the pressure on the internal
plunger R is required, as the slide itself is moved by the direct pressure
of the steam.
Having thus described the nature of the said Invention, and in what
manner the same is to be performed, I claim,―

page_text: arranged substantially as herein described in reference to Figs. 1, 2, 2ª,
3, 4, 4, 5, 6, and 7, wherein the slide plunger is fitted to move on fixed
tubular plungers, for the purposes set forth.
Second. The use for expansion valves of steam moved slide apparatus,
such as is referred to above, substantially as herein described in reference
to Figs. 8 to 15.
Third. The use of steam moved slide apparatus, constructed and
arranged substantially as herein described in reference to Figs. 18 to 21,
wherein the side plunger is fitted with an inner plunger moved relatively
to and fro within it, for the purposes herein set forth.
Fourth. The use of slide apparatus, constructed and arranged sub-
stantially as herein described in reference to Figs. 22 to 27, wherein the
movement of the slide in one direction is effected by the steam pressure,
and in the other direction by the movement of the main piston combined
with the steam pressure.
In witness whereof, I, the said Heinrich Adolf Hülsenberg, have
hereunto set my hand and seal, this Twentieth day of October,
in the year of our Lord One thousand eight hundred and seventy-
three.
HEINRICH ADOLF HÜLSENBERG. . (L.S.)