IMPROVEMENTS IN ROTARY ENGINES
Year: 1881

page_text: LETTERS PATENT to Benjamin Joseph Barnard Mills, of the Firm of Harris
and Mills, of 23, Southampton Buildings, in the County of Middlesex, Patent
Agent, for an Invention of "IMPROVEMENTS IN ROTARY ENGINES." A com-
munication from abroad by Pietro Dall 'Orto, of Genoa, in the Kingdom of
Italy, Engineer.
PROVISIONAL SPECIFICATION left by the said Benjamin Joseph Barnard
Mills at the Office of the Commissioners of Patents on the 23rd December
1881.
BENJAMIN JOSEPH BARNARD MILLS, of the Firm of Harris and Mills of
23 Southampton Buildings in the County of Middlesex Patent Agent. "IMPROVE-
MENTS IN ROTARY ENGINES." A communication from abroad by Pietro Dall'Orto
of Genoa in the Kingdom of Italy Engineer.
In this engine a continuous rotary motion is substituted for the alternate to and
fro motion of the piston in reciprocating engines.
By these means is obtained the main advantage of avoiding the loss of power
caused by the dead points of the crank and in the second place are avoided the
frictions in the slide which guides the piston. There is also obtained a considerable
economy in the frictions which result from the mechanism for the distribution of
the steam and to all these advantages presented by this engine must be added that
of occupying little space which would be very important if this engine were used
for marine purposes.
Calculations and experience have demonstrated that all these particulars of the
present engine render it capable of effecting an economy of 20 per cent. at the
least in the consumption of fuel which is verified in engines now in use.
The engine is constructed with two cylinders separated from each other by a
fixed division; within these cylinders turn two pistons or rather two discs fixed
upon the driving shaft.
Each of these discs carries a projection or piston proper of the form of a trapezoid
at the periphery of its exterior face. These projections or pistons are fixed on
opposite sides of the shaft.

page_text: The cylinders are so constructed as to form in each an annular space in which
works the projection or piston which rotates between the sides and the cylindrical
surface of the cylinder.
The steam by pressing against an abutment acts upon the projection or piston
which travels a quarter of its course pushed by the steam introduced into the
cylinder then the opening of the piston being no longer in connection with the
opening by which the steam enters, the stean is cut off and then that which is in
the interior space acts by expansion for the remainder of its course.
The two projections or pistons being always in opposite position to each other
and the steam acting upon them equally but not at the same time, it results that
there is a quarter revolution of each with full steam and that the shaft therefore
makes a half revolution with full pressure of steam.
The steam escapes by a tube into the open air or into a condenser.
The abutments in rising and falling permit the discharge of the steam.
The abutments are fitted with bronze packing pieces and it should be noted that
the projections or pistons and the abutments at their lower part are fitted with
bronze and the cylinders are provided with a complete lining in such manner that
besides the interior surface of the cylinder the cylindrical part is also lined upon
which slides the projection or piston.
The cylinder is fixed by bolts to the base as also are the supports of the driving
shaft.
The motion of the abutments is obtained by cams which give motion to a pulley
connected to an arrangement of articulated levers which form an articulated
parallelogram.
When it is desired-to-reverse the engine, by means of valves one set of passages
is closed and another is opened when the steam by entering on the opposite side-of
the projection or piston causes the latter to move in the contrary direction.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Benjamin Joseph Barnard Mills in the Great Seal Patent Office
on the 23rd June 1882.
BENJAMIN JOSEPH BARNARD MILLS of the Firm of Harris and Mills of
23 Southampton Buildings in the County of Middlesex, Patent Agent. "IMPROVE-
MENTS IN ROTARY ENGINES." A communication from abroad by Pietro Dall
'Orto of Genoa in the Kingdom of Italy Engineer.
In this engine a continuous rotary motion is substituted for the alternate to and
fro motion of the piston in reciprocating engines. By these means I obtain the
main advantage of avoiding the loss of power caused by the dead points of the
crank and in the second place I avoid the frictions in the slide which guides the
piston rod.
There is also a considerable economy in the frictions which result from the
mechanism for the distribution of the steam and to all these advantages presented
by this engine must be added that of occupying little space which would be very
important if the engine were used for marine purposes.
Calculations and experience have demonstrated that all these particulars of the
present engine render it capable of effecting an economy of 20 per cent, at the least
in the consumption of fuel which is verified in engines now in use.
In the accompanying Drawings Figure 1 represents a cross section of the
engine. Figure 2 represents a longitudinal section through the axis of the
cylinder. Figure 3 represents an end view of the engine. Figures 4 and 5 are
cross sections representing the interior of the two ends of the cylinder and the
cylindrical cap or lining. Figure 6 represents the interior and Figure 7 the
exterior of the end cover with the orifices for the admission of the motive fluid;
and Figure 8 represents the double cam for operating the rotary stop or abutinent.
A is the cylinder within which turn two pistons or rather discs fixed upon the
shaft E. These discs B are each provided with a tooth or projection M. These
projections are placed opposite to each other as shown at Figure 1 in which one of
the said projections is shown by dotted lines and the other by full lines..
In Figure 2 the two projections are shown in position diagonally opposite to
each other.
The cylindrical cap or lining L is placed beneath the projection M of the piston
in such manner that an annular space is left in which the projection M turns, such
annular space being formed between the sides or ends A¹ and the cylindrical parts
of the cylinder A and the surface of the cap or lining L.
In Figure 1 the piston B is shown in the position it would assume at the
moment when it receives the impulse from the steam which enters by the orifice J
in the end cover shown at Figure 4 and by the orifice H in the piston B.
The steam exerts its pressure upon the projection M by pressing against the
abutment C and in this way this projection accomplishes a quarter of its course
being pushed by the direct pressure of the steam; then the opening H in the
piston corresponding no longer with the opening J in the cover by which the
steam enters, the latter is cut off and then acts only by expansion for the remainder
of its course.
The projections M of the pistons being in position diagonally opposite to each
other and the steam acting upon them equally but not at the same time, it results
therefore that there is a quarter revolution given to each with the full pressure of
steam, that is to say, that the shaft will make a semi-revolution with full steam.
The steam may escape by the tube F into the air or into a condenser.

page_text: The abutments C turning to the right or to the left permit the passage of the
projections M after which they serve as abutments for the steam.
The reciprocating circular motion of the abutments C, is obtained by means of
the double cams D operating the connecting rods P, provided with trucks R, and
the cranks S, see Figures 2 and 3. These cams are shown at Figures 2 and 3 in
the position they would occupy when one of the pistons is working by the full
pressure of steam, and the other by expansion of the steam, the latter escaping by
the tube F.
In Figure 2 m m represent the stuffing boxes for the shafts of the abutments C.
If it is desired to reverse the motion of the engine, then by valves not shown
in the Drawings, the passages J are closed and those marked K are opened by
which means the steam is caused to enter the cylinder through passages H¹ on
the opposite side of the projection M of the piston thereby causing the latter to
move in the contrary direction.
Simultaneously with the opening and closing of the passages J and K by means
of levers the position of the abutments C is changed in order that they may serve
as abutments for the steam in the contrary direction.
The cylinder A is fixed by bolts upon the base Z upon which are also fixed the
standards N of the shaft E.
Having thus described the nature of the said Invention and the mode in which
the same is carried into effect I would have it understood that what I claim is.
First. The combination of cylinder A provided with inlet passages J and K
and outlet passages F with pistons B and projections M provided with inlet
passages H H³ substantially as herein shown and described and for the purpose
stated.
Second. The combinations with cylinder A pistons B and projections M-of-
abutments C operated by cranks S, connecting rods P and double cams D
substantially as herein shown and described and for the purpose stated.
In witness whereof I the said Benjamin Joseph Barnard Mills have hereunto
set my hand and seal this Twenty second day of June in the year of our
Lord One thousand eight hundred and eighty two.
D T D MIT T