IMPROVEMENTS IN PISTONS Bohemia
Year: 1882

page_text: LETTERS PATENT to Gerard Wenzeslaus von Nawrocki, Proprietor of the
firm of J. Brandt & G. W v Nawrocki, Patent Solicitor and Civil Engineer
of 124 Leipzigerstrasse Berlin Germany for an invention of "IMPROVEMENTS
IN
PISTONS
Bohemia
"
"
A communication from Philipp Langenstein of Prague
PROVISIONAL SPECIFICATION left by the said Gerard Wenzeslaus von
Nawrocki at the Office of the Commissioners of Patents on the 17th April
1882.
1
GERARD WENZESLAUS VON NAWROCKI Proprietor of the firm of J. Brandt,
& G. W. v. Nawrocki, Patent Solicitor and Civil Engineer of 124 Leipzigerstrasse,
Berlin, Germany. "IMPROVEMENTS IN PISTONS," (A communicationf rom Philipp
Langenstein of Prague Bohemia)
This Invention refers to improvements in pistons with metallic packing rings
and applicable for instance to steam hot air and gas engines and to pumps; the
main object is to prevent the metallic packing rings from becoming leaky through
wear. These rings are cut open and the tongue ends overlap generally into each
other with a very narrow end space say about 1/2 inch. This end space becomes
wider as the ring wears, and the ring becomes thinner, and a communication. is
made between the space before and behind the piston in the following manner.
To the inside of one end of the packing ring is fixed a plate which with its free
end extends over the slit or space between the ends of the cut ring and thus
makes joint so that the steam may pass between the ends of the ring on one side
and under the ring, hence press it against the cylinder, but so that the steam
cannot pass through to the other side of the ring, because of the aforesaid plate.
The plate may suitably be dovetailed into the ring and fastened thereto by a
countersunk rivet, this latter is however countersunk so deeply as not to touch the
cylinder even if the ring should wear down considerably. If the ring is to be
kept from shifting, steady pins may be screwed into the body of the piston.
This form of packing can only be used when the piston is fitted with two or
more rings, and it does not matter whether the piston works beyond the set off
or not.

page_text: This improvement is, because of its simplicity, very easily applied and old rings
are easily and cheaply adapted thereto.
The inventor has successfully applied this packing to a locomotive.
According to another modification the parts are so arranged that the steam
cannot get in between the ends of the ring and under the same, hence cannot force
them apart as in the construction described; the elasticity of the ring itself must
therefore press it against the cylinder.
Each end of the ring is fitted with a steel cross spline which is dovetailed where
they are let into the ring and fixed by deeply countersunk rivets. The splines are
formed with heads at top and bottom which extend into a joint plate made of gun
metal. The form of this plate depends upon as to whether the piston passes
beyond the offset and whether it is made with one or more rings. When the
piston has only one ring and passes beyond the set off; then the plate must be
applied to each side of the ring.
This plate has a slot in each side forming lugs and in these slots the ends of the
cross spline find their place.
When the piston does not pass the set off with one ring two plates may be used
and these plates are pressed against the cylinder by the ends of the cross splines.
The plates project into the body of the piston, hence cannot shift in tangential
direction they are deeper than the rings thus affording better guiding. They
make a perfectly tight joint and as the steam cannot press the ring against the
cylinder this latter cannot be worn oval. The rings must be kept in their position
so that the joint plates may always be guided by the ends of the splines; this is
'done by a steady pin.
To close the slit where the ring is cut a plate may be let into one end of the
ring behind it and be formed with a flange on each side of the ring; this plate is
fixed by means of deeply countersunk rivets and may conveniently be made of
brass. The flanges are let into the body of the piston and are prolonged beyond
that end of the ring to which the flange plate is fastened and prevent that end of
the ring from shifting tangentially while the other or free end of the ring fits
between the said prolongations of the flanges. At the opening between the ends
of the cut ring there may also be a conical steady pin to prevent the ring from
shifting. This construction is used for a piston with one ring.
For pistons with more than one ring the flange plate is made with only one
flange to each ring.
In both cases it is immaterial whether the piston works beyond the set off at
end of cylinder or not.
These latter constructions are not so perfect as those first described but simpler
and make a fairly tight piston packing. The ring is also in these cases not
exposed to the steam pressure but is by its own elasticity forced against the inside
of the cylinder. The constructions above described are suitable not only for steam
engines but also for gas, and hot air engines and for pumps air compressers and
other machinery.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Gerard Wonzeslaus von Nawrocki in the Great Seal Patent Office on..
the 17th October 1882:
GERARD WENZESLAUS VON NAWROCKI, Proprietor of the firm of J. Brandt.
& G. W v Nawrocki, Patent Solicitor and Civil Engineer of 124 Leipzigerstrasse
Berlin Germany. "IMPROVEMENTS IN PISTONS (A Communication from Philipp
Langenstein of Prague Bohemia)
"
This invention refers to improvements in pistons, with metallic packing rings
and applicable for instance to steam, hot air and gas engines and to pumps; the
main object is to prevent the metallic packing rings from becoming leaky through
wear. These rings are cut open and the tongue ends generally overlap into each
other as shewn at Figure 1 of the accompanying drawings, with a very narrow
end space say about 1/2 inch. This end space becomes wider as the ring wears,
and the ring becomes thinner, and a communication is made between the space
before and behind the piston in the following manner. The steam then as shown
by the arrows at Figure 1 enters between the ends of the ring, passes between the
lugs a of the piston ring and passes out between the ends of the ring on the other
side.
In order to prevent this the following arrangement is applied. Figure 2 is a
side view of a part of a, piston so constructed; Figure 3 is a plan section on
line A. A Figure 2. Figure 4 is a section through B. B Figure 2. Figure 5 is a
section through C. C Figure 2. Figure 6 is a detail. To the inside of one end of
the packing ring R is fixed a plate b which with its free end extends over the
slit or space between the ends of the cut ring and thus makes joint so that tho
steam may pass between the ends of the ring on one side and under the ring
hence press it against the cylinder but so that the steam cannot pass through to
the other side of the ring because of the aforesaid plate
The plate may suitably as shown in Figures 3 and 6 be dovetailed into the
ring and fastened thereto by a countersunk rivet d, this latter is however counter-
sunk so deeply as not to touch the cylinder even if the ring should wear down
considerably. If the ring R is to be kept from shifting, steady pins x may be
screwed into the body K of the piston.
This form of packing can only be used when the piston is fitted with two or
more rings and it does not matter whether the piston works beyond the set off
or not
This improvement is, because of its simplicity, very easily applied and old rings
are easily and cheaply adapted thereto.
The inventor has successfully applied this packing to a locomotive engine. The
piston rings of that engine were in such a condition that they required to be
renewed, the inventor provided them with the aforesaid packing plates, and the
following is a comparison between this engine and two others exactly like it.
The first engine with ordinary piston rings used per 2675 Kilometer 24 tons of
coal that is pro 100 kilometer 897-2 Kilograms or per English mile about 33 lbs of
coal. The second engine also with ordinary piston rings used per 4367 Kilometers.
385 tons of coal that is pro 100 Kilometers 8804 Kilograms or per English milė
about 321/2 lbs of coal. The third engine however the piston rings of which were
fitted with the new packing plates used per 4373 Kilometers 33 tons of coal,
hence per 100 Kilometer only 7556 Kilograms or per English mile about 27-05-lbs
of coal. In percentage the first Engine used 118.7% the second 116.5º and the
third 100. Tlie increased consumption of the first engine was. hence nearly 19%
and the second nearly 17°. This was corroborated by the amount of feed water
used.

page_text: According to another modification the parts are so arranged that the steam
cannot get in between the ends of the ring and under the same hence cannot force
them apart as in the construction described; the elasticity of the ring itself must
therefore press it against the cylinder.
Figure 7 is an outside view of a part of such a piston; Figure 8 is a plan
section through D D-Figure 7; Figure 9 is a similar section of a modified arrange-
ment of the joint plate. Figure 10 is a section through E. Figure 7, and
Figures 6 and 11 illustrate a detail.
འ
Each end of the ring is fitted with a steel cross spline Figure 11 which is
dovetailed where they are let into the ring and fixed by deeply countersunk
rivets h. The splines are formed with heads at top and bottom which extend
into a joint plate g made of gun metal. The form of this plate depends upon as to
- whether the piston passes beyond the offset and whether it is made with one or
more rings. When the piston has only one ring and passes beyond the set off,
then the plate g must as shewn in Figure 8 be applied to each side of the ring.
This plate has a slot in each side forming lugs gl and in these slots the ends of the
cross spline l'find their place.
These plates do not prevent the ring from expanding but are united to it by
the ends of the spline l as to any radial movement. If therefore the piston should.
pass beyond the set off the upper edge of the packing plate would not project
beyond that of the ring; it can therefore not be stopped by the set off when the
piston goes back,, which might easily happen if the packing plate were made of the
form shown at Figure 9.
When the piston does not pass the set off with one ring, two plates g may be
used as shewn at Figure 9, and these plates are pressed against the cylinder by the
ends of the cross splines l.
In pistons having two or more rings, even if they should pass beyond the set
off, the inner edge of the ring never passes beyond it hence the inventor in such
cases uses the plates shown at Figure 9 and one on each inner side of the ring.
This would look the same as shown at Figure 7.
The plates g project into the body K of the piston hence cannot shift in tan-
gential direction they are deeper than the rings thus affording better guiding.
They make a perfectly tight joint and as the steam cannot press the ring against
the cylinder, this latter cannot be worn oval, for the pressure or friction at the
admission that is when the piston stands at one end of the cylinder will be greater
with rings between the ends of which or below which the steam can get in than
when the piston has got to the middle of the stroke. The cylinder will therefore
gradually wear to the line of a hyperboloid. In this case also it is casy to adapt
this invention cheaply and. with the advantage that no tension springs are
needed.
The rings R must be kept in their position so that the joint plates may always
be guided by the ends of the splines, this is done by a steady pin x as shewn.
To close the slit where the ring is cut a plate m may as shewn at Figure 12
and at Figure 13 which latter is a section through F F Figure 12 be let into one
end of the ring behind it and be formed with a flange on each side of the ring;
this plate is shown separately at Figure 14; it is fixed by means of deeply counter-
sunk rivets o and may conveniently be made of brass. The flanges are let into
the body K of the piston and are prolonged beyond that end of the ring to which
the flange plate is fastened and prevent that end of the ring from shifting
tangentially while the other or free end of the ring fits between the said pro-
longations of the flanges. At the opening between the ends of the cut ring. there
may also be a conical steady pin x to prevent the ring from shifting. This
construction is used for a piston with one ring.
For pistons with more than one ring the flange plate is as shown at Figures 15
and 16 the latter being a section through G G Figure 15 made with only one
A

page_text: In both cases it is immaterial whether the piston works beyond the set off at
end of cylinder or not.
These latter constructions are not so perfect as those first described but simpler
and make a fairly tight piston packing. The ring is also in these cases not exposed
to the steam pressure but is by its own elasticity forced against the inside of the
cylinder.
The constructions above described are suitable not only for steam engines but
also for gas and hot air engines and for pumps, air compressors and other
machinery.
.
I claim as the invention communicated to me and for pistons. with metallic
packing for steam engines, hot air and gas engines, pumps, air compressors and
other machinery.
First: The arrangement of the packing plates & Figures 2 to 6, which are
fastened at and below one end of the ring R and extend under the other end of the
ring substantially as set forth.
Second: The arrangement of the packing plates g Figures 7 to 10, at the side
of the ends of the ring in combination with the spline substantially as set
forth..
Third: The arrangement of the whole or half packing shoe m or n substantially
as set forth with reference to Figures 12 to 16.
In Witness whereof I the said Gerard Wenzeslaus von Nawrocki have
hereunto set my hand and seal this Twelfth day of October in the year of
our Lord One thousand eight hundred and eighty two.
GERARD WENZESLAUS VON NAWROCKI (LS.)