IMPROVEMENTS IN ROTARY ENGINES
Year: 1879

page_text: LETTERS PATENT to Benjamin Joseph Barnard Mills, of the Firm of Harris and
A
Mills, of 23, Southampton Buildings, in the County of Middlesex, Patent
Agent, for the Invention of "IMPROVEMENTS IN ROTARY ENGINES."
communication from abroad by William Nelson De Groat, Senior, Iron and
Brass Founder, and Anthony Leggett Maxwell, Car Wheel Maker, both of
Knoxville, in the State of Tennessee, United States of America.
PROVISIONAL SPECIFICATION left by the said Benjamin Joseph Barnard
Mills at the Office of the Commissioners of Patents on the 6th October
1879.
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 William Nelson
De Groat, Senior, Iron and Brass Founder, and Anthony Leggett Maxwell, Car
Wheel Maker, both of Knoxville, in the State of Tennessee, United States of
America.
The improved engine is constructed with a disc mounted on a shaft, and having a
piston head which works in a stationary annular cylinder so as to impart rotation
to the disc, and thereby to the shaft.
The steam and exhaust ports enter the disc at or near its centre, and pass to its
periphery in opposite directions, the steam port communicating with the cylinder
through one face of the piston-head, and the exhaust port at a diametrically
opposite point. The necessary abutments are formed by equidistant radially sliding
heads operated by a cam wheel on the main shaft. The exhaust port and other
parts are so arranged that each sliding head is relieved of pressure before it has to
be moved in and it is restored to its place under a pressure which is balanced with
the exception of the small area of the stem by which it is worked.
For a reversing engine a steam port is provided on each face of the piston-head,
and a plug in the disc having connection ports, which, by turning this plug in
either direction are caused to place either of the said ports in the head in com-
munication with the central steam port of the disc, and the other with the exhaust
port.
It is preferred to use three radially sliding abutments to a disc having one piston
head. The Invention may however be used to good advantage with two piston
heads on the rotary disc, and a corresponding number of main exhaust ports
intermediately arranged, and with four radially sliding abutment-heads in the
annular cylinder.
Other modes of introducing the steam through the disc may be substituted
without departing from the essential principle of the Invention.

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 6th April 1880.
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 William Nelson
De Groat, Senior, Iron and Brass Founder, and Anthony Leggett Maxwell, Car
Wheel Maker, both of Knoxville, in the State of Tennessee, United States of
America.
The improved engine is constructed with a disc mounted on a shaft, and having
a piston head which works in a stationary annular cylinder so as to impart
rotation to the disc, and thereby to the shaft.
The steam and exhaust ports enter the disc at or near its centre, and pass to
its periphery in opposite directions, the steain port communicating with the cylinder
through one face of the piston head, and the exhaust port at a diametrically
opposite point. The necessary abutments are formed by equidistant radially
sliding heads operated by a cami wheel on the main shaft. The exhaust port and
other parts are so arranged that each sliding head is relieved of pressure before it
has to be moved, and it is restored to its place ander a pressure which is balanced
with the exception of the small area of the stem by which it is worked.
For a reversing engine a steam port is provided on each face of the piston head
and a plug in the disc having connection ports, which, by turning this plug in
either direction, are caused to place either of the said ports in the head in com-
munication with the central steam port of the disc, and the other with the exhaust
port.
It is preferred to use three radially sliding abutments to a disc having one piston
head.
The Invention may however be used to good advantage with two piston heads
on the rotary disc, and a corresponding number of main exhaust ports inter-
mediately arranged, and with four radially sliding abutment heads in the annular
cylinder.
Other modes of introducing the steam through the disc may be substituted
without departing from the essential principle of the Invention.
And in order that the said Invention may be clearly understood and readily
carried into effect, I will proceed, aided by the accompanying Drawings, more
fully to describe the same.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a vertical transverse section of the engine on the line 1-1,
Figure 2.
Figure 2 is a vertical longitudinal section on the line 2-2, Figure 1.
Figure 3 is a transverse section showing an engine with two pistons.
A represents a suitable base or bed on which the standards or pillow-blocks B, B,
and the annular cylinder C are fastened. The main shaft S has its bearings on the
pillow-blocks B, B, and has keyed on its forward end a disc D, on which are one
or more piston heads E fitting within the annular cylinder C; F, F, are packing
rings set up against the faces of the disc D in customary manner in order to confinc
the steam within the annular cylinder.
G represents the stationary steam supply pipe communicating with the centre of
the disc D, and H the exhaust pipe which communicates constantly with an
annular exhaust port H in the disc surrounding the central steam port G', which

page_text: communicates with the steam pipe G. The steam pipe G is confined, and the joint
between it and the rotary disc D, packed by means of a gland I. From the central
steam port in the disc a port g extends radially to a plug J, by which said radial
steam port is made to communicate with the port g¹ or g on either side of the
piston head E, according to the direction in which the engine is run. The other
port g or g, as the case may be, is, by the same adjustment of the plug, placed in
communication with the exhaust port 2 or ¹, connecting with the annular exhaust
port H. The ports in the plug to adapt it to thus control the steam, and tho
inovement of the engine are shown in Figure 1, g being a Y or V shaped port
to connect the central steam port g with either of the ports g' or g, and le³, h³,
curved exhaust ports which connect the other port or g¹ with the exhaust
port or ', as before stated.
The main exhaust port of the disc is shown at H. This port is always open,
and is located diametrically opposite the piston head E, where but a single piston
is used. If two pistons are used the respective exhaust ports are located a short
distance in advance of them, as illustrated in Figure 3, but this arrangement is not
suitable for a reversing engine. In non-reversing engines with either one or more
pistons the reversing plug J, and its accessories may be entirely omitted, the
stopping and starting being effectually controlled by the throttle. K¹, K, K³, are
the radially sliding abutments, which are operated by rods L passing through
stuffing boxes M, and connected by arms N and rods O to levers P, fulcrummed
at p, and having on their shorter arms spherical friction rollers 2', which travel in
the cam groove of a wheel Q, keyed on the main shaft S.
The form of the cam groove q is such that each radially sliding head K is with-
drawn a short time before the piston E reaches that point in the cylinder, and is
closed again directly behind the piston. It will further appear from the positions
of the parts shown in Figure 1 that each sliding head or abutment is relieved of
steain pressure before the next preceding abutment is retracted for the passage of
the piston. In the position shown in Figure 1 the main exhaust port 1 has
just cleared the space from K³ to K¹ of steam, the space from K to Ks having been
cleared as said exhaust port passed the abutment at K². The full steam pressure
is acting between the abutment K¹ and the piston E. In Figure 2 the piston head
is shown in the opposite position just passing the lower abutment head K³, said
hend being retracted to permit it to pass.
The exhaust H inay carry off the steam in any preferred direction. The arrange-
ment shown in Figure 2, whereby it delivers it through the floor is convenient.
The exhaust pipe H may be turned in any radial direction.
It is preferred to connect the stationary steam and exhaust port with the web
near its central part, as described, but this is not essential to the Invention.
Figure is a front view, and Figure 5 is a longitudinal section of the modifica-
tion in which the steam is introduced through a concentric annular groove g' in the
face of the disc D, having a packed connection with a corresponding groove in a
stationary casing R, and the exhaust may be taken out in similar manner through
a groove within or on the outer side of the steam groove. Other modes of
introducing the steam through the disc may be substituted without departing from
the essential principle of the Invention.
T shows a driving pulley on the shaft S.
Having thus described the nature of the said Invention, and the node in which
the same is carried into effect, I would have it understood that what I claim is,―
First. The combination of the cylinder C, rotating disc D, having one or more
piston heads E, the steam pipe G in line with the solid shaft S, the central and
radial steam ports G', g, within the rotating disc D, the radially sliding abut-
ments K', K³, K³, the cam wheel Q, and the levers P, P, P, substantially as and for
the purposes described.
Second. The combination with the cylinder C, disc D, and piston head E of the
steam ports G', g, g', g², exhaust ports H, H₁, h, h, and the plug or valve J,

page_text: provided with channels g³ and ³, and turning on an axis parallel with that of the
disc, substantially as and for the purposes set forth.
Third. The combination of the cylinder C, solid shaft S, rotary disc D,
piston head E, abutments K¹, K², K³, annular exhaust port H¹, and the external
radial exhaust pipe H communicating directly with said annular exhaust port H',
substantially as and for the purposes set forth.
In witness whereof, I, the said Benjamin Joseph Barnard Mills, have
hereunto set my hand and seal, this Second day of April, in the year of our
Lord One thousand eight hundred and eighty.
TITTS
B. J. B. MILLS. (..)