IMPROVEMENTS IN ROTARY STEAM ENGINES
Year: 1880

page_text: LETTERS PATENT to Peter Jensen, of 33, Chancery Lane, London, for an
Invention of "IMPROVEMENTS IN ROTARY STEAM ENGINES." A communication
from abroad by Julius Nilsen, of Kotka, in the Grand Duchy of Finland.
PROVISIONAL SPECIFICATION left by the said Peter Jensen at the Office
of the Commissioners of Patents on the 14th April 1880.
PETER JENSEN, of 33, Chancery Lane, London. "IMPROVEMENTS IN ROTARY
STEAM ENGINES." A communication from abroad by Julius Nilsen, of Kotka, in
the Grand Duchy of Finland.
The object of these improvements is to surmount the difficulties heretofore
experienced in rotary engines as regards keeping the piston tight against the ends
or covers of the cylinder, and against the inner circular surface of the cylinder,
and to construct a rotary engine which shall have lasting efficiency.
In the cylinder is placed another cylinder of a smaller diameter and eccentrically
thereto; this smaller cylinder carries the driving shaft which passes out through
a stuffing box at each cylinder cover or end; the small cylinder rests on the
bottom of the larger cylinder, so that there is a space above between the two.
There is a rectangular slot through the small cylinder, and in this fits a flat piston
in two prismatic parts, steam is let into the interior of the inner cylinder, and into
the space between the two parts of the piston, and forces them apart; there are
set screws between them for preventing the parts of the piston from getting into a
wrong position when the steam is shut off, and the engine is turned by hand; the
screws are set so that they just touch the other part of the piston when the
piston stands horizontally, the space between the two parts of the piston is then
the least. The inner cylinder and the piston work steam tight at one end against
one of the cylinder covers; at the other end they work steam tight against a loose
or movable ring disc between it and the cylinder cover at that end, which disc by
packing or piston rings works steam tight in the cylinder, and is pressed against
the end of the piston by steam. There is a port passing down on each side of
the cylinder, one for steam admission, the other for exhaust to the air or to a
condensor.
The direction of rotation is determined by a cock or valvos.
In the outer edge of each part of the piston there is a half round recess, in which
works a half round packing piece fitting the interior curve of the cylinder, and
able to adapt itself thereto during the rotation with sufficient surface for being
steam tight.
In the bottom of the cylinder where the inner or piston cylinder touches it there
is a wearing piece inserted with packing or spring below, and sot screws for setting
it up or adjusting the pressure.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Peter Jensen in the Great Soal Patent Office on the 14th October
1880.
PETER JENSEN, of 33, Chancery Lane, London. "IMPROVEMENTS IN ROTARY
STEAM ENGINES." A communication from abroad by Julius Nilsen, of Kotka, in
the Grand Duchy of Finland.
The object of theso improvements is to surmount the difficulties heretofore
experienced in rotary engines as regards keeping the piston tight against the ends
or covers of the cylinder and against the inner circular surface of the cylinder,
and to construct a rotary engine which shall have lasting efficiency.
And in order that this Invention may be fully understood, I will describe it
with reference to the accompanying Drawings, of which Figure 1 is a vertical
longitudinal section through such an engine; Figure 2 is a vertical cross section,
and Figure 3 a horizontal section through same; Figure 4 is a horizontal section
through the cylinder, and Figure 5 a part view of the piston.
In the cylinder A is placed another cylinder B of a smaller diameter and
eccentrically thereto; this smaller cylinder B carries the driving shaft which passes
out through a stuffing box at each cylinder cover or end C and D; tho small
cylinder rests on the bottom of the larger cylinder at the line a, b, so that there is
a space above between the two. There is a rectangular slot through the small
cylinder, and in this fits a flat piston in two prismatic parts E and F with a space
between; steam is let into the interior of the inner cylinder and into the space
between the two parts E and F of the piston by the ports r, Figure 3, and forces
them apart; there are set screws o between them for preventing the parts of the
piston from getting into a wrong position when the steam is shut off, and the
engine is turned by hand; the screws are set so that they just touch the other part
of the piston, when the piston stands horizontally or a quarter stroke from the
position shown on the Drawing; the space between the two parts of the piston is
then the least; during the whole stroke the inner cylinder and the piston work
steam tight at one end against one of the cylinder covers, videlicet, O; at the other
end they work steam tight against a loose or movable ring disc G between it and the
cylinder cover D at that end, which disc by packing or piston rings works steam
tight in the cylinder, and is pressed against the end of the piston by steam; K is
a steam pipe for admitting steam to this part; the pressure may be regulated by a
cock K¹. There is a port m in Figures 2 and 4 passing down on each side of the
cylinder to the port a, b, one for steam admission, the other for exhaust to the air
or to a condenser.
The fresh steam enters by the pipe H into the left hand side port m, as shown
in Figure 2, and pressing on the piston part E forces the latter with the inner
cylinder B round in the direction of the arrow, and as after half a revolution the
other piston part F is pressed on in a similar manner, it follows that the inner
cylinder B together with the engine shaft obtains a continuous rotary motion.
The direction of rotation is determined by a cock or valves for reversing the
action of the pipes H and L
The novelty of this Invention so far described consists in the application of the
false or intermediate loose ring G between the inner cylinder B and the cover D,
while in the older or usual constructions the parts B and D touch each other, and
cannot keep tight for any length of time. In this construction on the contrary the
steam pressure itself against the outside of the loose ring G makes a joint against
the end of B, and this pressure can be regulated as already described. The ring G
has a ring or other elastic packing at its circumference for making a joint there.
Another novel feature is the construction of the two parts E and F forming the

page_text: piston, videlicet, in the outer edge of each part of the piston there is a half round
recess in which works a half round packing piece fitting the interior curve of the
cylinder, and able to adapt itself thereto during the rotation with sufficient surface
for being steam tight, see Figures 1, 2, and 5. This arrangement admits of various
positions of the piston E, F, the pieces remaining constantly in perfect contact
with the interior surface of the cylinder A
In the bottom of the cylinder where the inner or piston cylinder touches it
there is a wearing piece y inserted with packing y or spring below, and set
screws v for setting it up or adjusting the pressure; is a plate between the set
screws and the packing piece y'.
And having thus described and ascertained the nature of this Invention, and
the mode of carrying the same into effect, as communicated to me I declare that I
claim,-
Firstly. The application of an intermediate piston like disc G between the end
cover D and the rotary piston cylinder B and exposed to the steam pressure so as
to form an elastic steam tight joint as set forth.
Secondly. The application of the pieces working in half circular recesses in the
ends of the piston, consisting of the pieces E and F which are pressed apart by
steam for making a joint between said piston and the interior of the cylinder in all
positions as set forth.
Thirdly. The application of an adjustable piece y at the point of contact between
the cylinder A and the piston cylinder B for the purpose of making a joint at
this place as set forth.
In witness whereof, I, the said Peter Jensen, have hereunto set my hand
and seal, this Fourteenth day of October, in the year of our Lord One
thousand eight hundred and eighty.
TRAnn TTAC