AN IMPROVED ROTARY WATEB OR STEAM MOTIVE POWER ENGINE."
Year: 1867

page_text: LETTERS PATENT to William Bradshaw Leachman, of Leeds, in the County
of York, Engineer, for the Invention of "AN IMPROVED ROTARY WATEB
OR STEAM MOTIVE POWER ENGINE."
PROVISIONAL SPECIFICATION left by the said William Bradshaw
Leachman at the Office of the Commissioners of Patents, with his
Petition, on the 10th December 1867.
I, WILLIAM BRADSHAW LEACHMAN, of Leeds, in the County of York,
Engineer, do hereby declare the nature of the said Invention for "AN IM-
PROVED ROTARY WATER OR STEAM MOTIVE POWER ENGINE," to be as follows:-
Through the sides or ends of a cylinder of suitable dimensions I pass a
shaft. Upon this shaft and within the said cylinder I mount another smaller
cylinder provided with two recesses opposite to each other and placed
eccentrically with regard to the outer cylinder, the inner and outer cylinders
touching in one portion of their respective circumferences, leaving on the
opposite side a space; I also cast to the inner surface of one end of the outer
cylinder a double ring or internal eccentric which is concentric with the outer
cylinder or casing itself, but not with the shaft which passes through it.
Within this double ring two or more sliding guide blocks are free to move
and with them are connected two or more bars (by means of fast studs)
which extend from the axis aforesaid to the inside of the said outer cylinder
and pass respectively through slot holes in the surface of the inner cylinder,

page_text: such slot holes being opposite to the recesses before named. To each of
these bars is attached a feather or float extending the whole width of the
cylinder. I may bere add that the pins by which the bars are connected to
the slide blocks admit of the floats along with the bars to which they are
attached receding from the centre of the shaft as they are urged by the
eccentric. The cylinder is provided with ports placed opposite to cach
other for the admission and emission of steam or water whichever may
be used. Admitting steam, for instance, at the lower side it passes between
the two cylinders on that side where they are furthest from each other until
it reaches the recess before spoken of on the surface of the inner cylinder, and
here it comes in contact with the feather or float before alluded to. This
presenting a surface of resistance is driven round, and as it approaches the
upper portion of the outer cylinder gradually withdraws towards the centre by
means of the eccentric arrangement before named. It now reaches the
ejection port at which the steam passes out of the cylinder, one of the other
feathers or floats meantime reaching the admission port for a fresh charge,
and as the first float comes round to its first position it is gradually drawn
closer and closer towards the centre until it reaches that point where the two
cylinders touch each other. Passing that point as it approaches the steam
port the eccentric ring on the outer cylinder gradually urges it out and the
operation is repeated.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Bradshaw Leachman in the Great Seal Patent
Office on the 10th June 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
BRADSHAW LEACHMAN, of Leeds, in the County of York, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of December, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Bradshaw Leachman, Her special licence that I, the said William
Bradshaw Leachman, my executors, administrators, and assigns, or such
others as I, the said William Bradshaw Leachman, my executors, adminis-
trators, 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;

page_text: should 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 "AN IMPROVED ROTARY WATER OR STEAM MOTIVE
POWER ENGINE," upon the condition (amongst others) that I, the said
William Bradshaw Leachman, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and scals, 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 Seal Patent Offico within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Bradshaw Leachman, do
hereby declaro the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :-
Through the sides or ends of a cylinder of suitable dimensions I pass a
shaft. Upon this shaft and within the said cylinder I mount another smaller
cylinder provided with two recessos opposite to each other and placed
cccentrically with regard to the outer cylinder, the inner and outer cylinders
touching in one portion of their respective circumferences, leaving on the
opposite side a space; I also cast to the inner surface of one end of the outer
cylinder a double ring or internal eccentric which is concentric with the outer
cylinder or casing itself, but not with the shaft which passes through it. Within
this double ring three slide blocks are free to move, and with them are con-
nected three bars (by means of fast studs) which extend across the diameter
of the cylinder and pass respectively through slot holes in the surface of the
inner cylinder, such slot holes being opposite to the recess before named. To
each of these bars is attached a feather or float extending the whole width
of the cylinder. I may here add that the pins by which the bars are con-
nected to the slide blocks admit of the floats along with the bars to which
they are attached receding from the centre of the shaft as they are urged by
the eccentric. The cylinder is provided with ports placed opposite to each
other for the admission and emission of steam or water whichever may be
used. Admitting steam, for instance, at the upper side it passes between the
two cylinders on that side were they are furthest from each other until it
reaches the recess before spoken of on the surface of the inner cylinder, and
here it comes in contact with the feather or float before alluded to. This
presenting a surface of resistance is driven round, and as it approaches the
upper portion of the outer cylinder gradually withdraws towards the centre by.
means of the eccentric arrangement before named. It now reaches the

page_text: ejection port at which the steam passes out of the cylinder, the consecutive
feather or float meantime reaching the admission port for a fresh charge, and
as the first float comes round to its first position it is gradually drawn closer
and closer towards the centre until it reaches that point where the two
cylinders touch each other. Passing that point as it approaches the steam
port the eccentric ring on the outer cylinder gradually urges it out and the
operation is repeated. In some instances, however, I prefer to admit the steam
where the inner and outer cylinders come in contact, admitting such steam
through a slide valve circular in its formation and provided with three ports, as
will be explained in the description of Drawings; I also use gearing to rotate
the shaft upon which the valve is keyed. I use an ordinary throttle valve and
governor apparatus which may also be worked in the manner usual in
ordinary engines.
In order however that my Invention may be the better understood reference
is made to the accompanying Sheet of Drawings, and to the letters and figures
marked thereon, that is to say :-
DESCRIPTION OF THE DRAWINGS.
Figure 1 shews a side elevation of the engine with the adjuncts of throttle
valve and governor before referred to, and Figure 2 a section of the engine,
Figure 3 being a detail which shews the formation of the floats. Referring
to Figure 2 letter A shews the circular valve with the three ports a, a, a;
letters B, Figure 1, denote the gearing by which such valve keyed on the shaft b
receives the requisite motion for the purposes of admission of steam where steam
is used. It will be apparent that upon the steam entering through the junction
pipe c into the pipe d of the cylinder D that it will come in contact, after
passing up the recess between the outer cylinder D and the inner cylinder E,
with the float f. 1 and give the result previously named, the respective floats
being urged inwards and outwards in their circular rotation by the action of
the eccentric G and H upon the respective bars h to which they are connected.
In the Drawing filed herewith it will be seen that three floats fare provided
and consequently three ports a to the valve, so that as each float approaches
the port d one of the ports a is there ready to supply the steam where steam
is used requisite to urge it round; as each float approaches the opening I tho
steam is of course emitted no resistance being offered to it. The governor J¹
and throttle valve arrangement K with the intermediate connection being well
understood and their junction through the pipe k with the engine it is unneces-
sary to describe further than to remark that such governor arrangement is
driven from the small pulley on the shaft L communicating by means of a

page_text: belt with the pulley M, Figure 3. Figure 3 shows the float with a spring
and wedge pieces in dotted line, Figure 4 showing an end view of the float
so recessed. It may here be observed that lining or packing rings adjusted
by set screws are sometimes used, as shewn in dotted lines in Figure 2, to
save the wear of the ends of the casing.
Having now fully shewn & described the nature of my Invention I wish
it to be understood that what I claim as novel and of my Invention is,―
Firstly. The arrangement of a rotating drum fixed concentrically with the
shaft upon which it is keyed, but eccentrically with the outer casing.
Secondly. The method, shewn and described, whereby the vanes or floats
are constantly retained in the desired position, not being allowed free action.
Thirdly. The arrangement of loose pieces fitted into the recessed vanes or
floats (shewn in Figures 3 and 4), such pieces being constantly kept up to
the internal surface of the outer casing and to the ends of the same by means
of internal springs.
Fourthly. The arrangement of the rotating valve, shewn and described,
whereby steam may be admitted at any given point and cut off so as to work
expansively.
In witness whereof, I, the said William Bradshaw Leachman, have
hereunto set my hand and seal, this Ninth day of June, in the year
of our Lord One thousand eight hundred and sixty-eight.
WILLIAM BRADSHAW LEACHMAN. (L.S.)
Witness,
PHILIP H. SHARP,
Patent Agent,
18, East Parade,
Leeds.