IMPROVEMENTS IN PRESSURE-GOVERNED SLIDE VALVES
Year: 1868

page_text: LETTERS PATENT to Alexander Baumann, of Heilbronn, Wurtemberg,
but now residing in Cecil Street, in the County of Middlesex, for
the Invention of "Toon
Sealed the 11th June 1869, and dated the 15th December 1868.
PROVISIONAL SPECIFICATION left by the said Alexander Baumann at
the Office of the Commissioners of Patents, with his Petition, on
the 15th December 1868.
I, ALEXANDER BAUMANN, of Heilbronn, Wurtemberg, but now
residing in Cecil Street, in the County of Middlesex, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN PRESSURE-GOVERNED
SLIDE VALVES," to be as follows:-
It has been heretofore proposed to actuate the valve of a pressure
engine by connecting it to a special piston working in a special cylinder,
and to govern the admission of pressure to and the exhaust of such
special cylinder by a second slide valve moving reciprocally with the
piston of the engine, commencing and ending its stroke therewith, and

page_text: being either the piston itself or being invariably fixed to the piston, or
connected to the same by a lever.
The present Invention consists in the addition of another slide valve
to the two slide valves previously mentioned. In carrying out this Inven-
tion the valve of the engine is actunted by connecting it to a special
piston working in a special cylinder. The admission of pressure to and
the exhaust of the latter is governed by the combined effects of a second
and a third slide valve, the second slide valve being the piston. itself,
and the third slide valve being actuated by a special piston working.in
a special cylinder, having pressure and exhaust in common with the
cylinder of the engine through ordinary steam ways. In this arrange-
ment two passages are formed in the cylinder, the same being respoc-
tively near cither end thereof, the piston passing over them as a slide
valve. When the piston of the engine near-the-end-of-its-stroke_bas_
passed over the corresponding passage, the slide valve-of-the-engine,
which may be called the "main valve," is shifted, because the said
passage is made to lead the pressure to one face of the "main valve"
piston, whilst its opposite face is exposed to the atmosphere. The
leading of the pressure-to-one-face-of-the "main_valve " piston whilst its
other face is exposed to the atmosphere is due to the disposition of the
third slide valve, which latter is connected to a special piston working
in a special cylinder, having pressure and exhaust in common with the
cylinder of the engine through ordinary steam ways. This third valve
may be termed the "leading valve." By the shifting of the "main
valve" its own piston is released, and the piston of the engine and the
"leading valvo" begin a new stroke. By this new stroke the "leading
valve" shuts the passage through which the pressure has last passed,
and brings the corresponding face of the "main valve" piston in com-
munication with the atmosphere, whilst the other face of the last-
mentioned piston is placed in communication with the passage near the
new stroke of the engine piston, and thus as soon as the engine piston
has passed over it pressure is admitted upon one face of the "main
valve" piston, and the same movements as before described take place
in the opposite direction.

page_text: SPECIFICATION in pursuance of tlic conditions of the Eetters Patent,
filed by the said Alexander Baumann in the Great. Seal. Patent
Office on the 15th June 1869:-
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
BAUMANN,. of Heilbronn, Würtemberg, and lately residing in Cecil
Strect,. Strand, in the County of Middlesex, but now of Olapham, in the
County of Surrey,.send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of December, in the year
of our Lord. One thousand eight hundred and sixty-cight, in the thirty-
second year of Hor reign,.did, for Herself, Her heirs and successors, give
and grant unto me, the said. Alexander Baumann, Her spécial licence
that I, the said Alexander Baumann; my executors, administrators,. and
assigns, or such. others as I, the said Alexander Baumann, 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, sliould 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 PRESSURE--
GOVERNED SLIDE VALVES," upon the condition (amongst others) that I, the
said Alexander Baumann,.my executors or administrators, by an instru--
ment in writing under my, or their,.or. one of their hands and seals,.
should. particularly 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 Scal Patent Office within six.
calendar months next. and immediately after the date of. the said.Letters,
Patent..
NOW KNOW YE, that I, the said Alexander Baumann, do hereby-
declare the nature of my said Invention, and in what manner the same:
is to be performed, to be particularly described. and ascertained in.
and by the following statement, reference being. had. to the annexed.
Drawings, and to the figures and letters marked thereon, that is to.
say:-
It has been heretofore proposed to actuate the valve of a. pressure.
engine by connecting it to a special piston working in a special cylinder.
and to govern the admission of pressure to and the exhaust of such

page_text: special cylinder by a second slide valve moving reciprocally with the
piston of the engine commencing and ending its stroke therewith and
being either the piston itself or being fixed to the piston or connected to
the same by a lever.
My said Invention consists in the addition of another slide valve to
the two slide valves previously mentioned, and in carrying out the same
the valve of the engine is actuated by connecting it to a special piston
working in a special cylinder. The admission of pressure to and the
exhaust of the latter is governed by the combined effects of a second and
third slide valve, the second slide valve being the piston itself, and the
third slide valve being actuated by a special piston working in a special
cylinder having pressure and exhaust in common with the cylinder of
-the-engine-through ordinary steam ways. In this arrangement two
passages are formed in the cylinder, the same being respectively near
either end thereof, the piston passing over them as a slide valve. When
the piston near the end of its stroke has passed over the corresponding
passage the slide valve of the engine, which may be called the main
valve, is shifted by reason of the said passage leading the pressure to one
face of the main valve piston, whilst its opposite face-is-exposed-to-the-
atmosphere. The leading of the pressure to one face of the main valve
piston whilst its other face is exposed to the atmosphere is due to the
disposition of the third slide valvo, which latter is connected to a special
piston working in a special cylinder having pressure and exhaust in
common with the cylinder of the engine through ordinary steam ways.
This third valve may be termed the "leading" valve. By the shifting
of the "main valve" its own piston is released, and the position of the
engine and the "leading valve" begin a new stroke. By this new stroke
the "leading valve" shuts the passage through which the pressure has
last passed and brings the corresponding face of the "main valve" piston
in communication with the atmosphere, whilst the other face of the last-
mentioned piston is placed in communication with the passage near the
end of the new stroke of the engine piston, and thus as soon as the
engine piston has passed over it pressure is admitted upon one face of
the "main valve" piston, and the same movements as before described
take place in the opposite direction.
I will now refer to the annexed Drawings, from which the nature of
my said Invention will be more clearly understood. The same letters
of reference indicate similar parts in the several Figures.

page_text: Figure 1 represents an elevation of the cylinder of the engine and its
valve chest, and Figure 2 is a section through the valve chest. It will
be observed that piston valves are used which are slide valves and at
the same time pistons working in special cylinders. Before explaining
the action of the valves it should be remarked that the pistons E and F
in the piston valves A and B are not entirely tight and serve therefore
to prevent too sudden action resulting from the pressure to which they
are subjected. Pieces of india-rubber are shewn at H, the object of
which is to prevent noise which might be occasioned by the contact of
the piston valve and the cover. The hole I is the pressure inlet, and K
is the exhaust.
The slide valve, in the construction and addition of which my said
Invention consists, is the piston valve represented at A, and by the com-
bined effects of which and the piston of the engine acting as a slide
valve, the admission of pressure to and the exhaust of the main piston
valve B is governed. The piston valve A has pressure and exhaust in
common with the cylinder of the engine through ordinary steam ways
C and D. Two passages D, D, are formed in the cylinder, the same
being respectively near either end thereof, and the piston passing over
them as a slide valve. When the piston of the engine has near the end
of its stroke passed over the corresponding passage D, the main piston
valve B is shifted, because the passage D leads the pressure to the main
piston valve B, after having pushed back the piston valve A, which is
effected by reason of the latter having its opposite face exposed to the
exhaust or atmosphere K, as well as the main piston valve B. The
leading of the pressure to one face of the main piston valve B whilst its
other face is exposed to the atmosphere K is due to the disposition of the
piston valve A, which has pressure and exhaust in common with the
cylinder of the engine through the ordinary steam ways C and D. The
third piston valve A may be termed the "leading valve." By the
shifting of the main piston valve B the pressure which has shifted it is
released, and the pressure in the cylinder is turned into exhaust, the
exhaust in the cylinder into pressure to the piston of the engine, and the
leading valve A begins a new stroke, the piston valve A returning into
the position in which it is represented in the Drawing. In order to
prevent its being thrown out of this position by any accident when
pressure is on both faces of the valve A, its two faces are made of
unequal surface, so that the resulting pressure keeps it in the indicated

page_text: position. By its new stroke as described the leading piston valve A
shuts the passage through which the pressure has last passed, and brings.
the corresponding face of the main piston valve in communication with
the atmosphere K, whilst the other face of the last-mentioned piston
valve B is placed in communication with the passage D shortly before
the new stroke of the engine piston, and thus as soon as the engine
piston has passed over the passage D pressure is admitted upon one face
of the main piston valve B and the same movements as before described.
take place in the opposite direction.
Having thus described and ascertained the nature of my said In-
vention, and the manner in which it is to be performed, I would obscrvc.
in conclusion that what I consider novel and original and therefore
claim as constituting the Invention secured to me by the said herein-
before in part recited Letters Patent is, the construction-and-arrange--
ment of pressure-governed slide valves, substantially as and for the pur-
poses hercin-before described and set forth, or any mere modifications.
thereof.
In witness whercof, I, the said Alexander Baumann, have here-
unto set my hand and seal, this Fourteenth day of June, in-the-
year
of our Lord One thousand eight hundred and sixty-nine.
Witness,
R. S. MORDAUNT VAUGHAN,
54, Chancery Lane.
A. BAUMANN. (L.S.)