IMPROVEMENTS IN ROTARY PROPELLERS, PUMPS, AND FANS
Year: 1868

page_text: LETTERS PATENT to Matthew Piers Watt Boulton, of Tew Park, in
the County of Oxford, Gentleman, and John Imray, of West-
minster Bridge Road, in the County of Surrey, Engineer, for the
Invention of "IMPROVEMENTS IN ROTARY PROPELLERS, PUMPS, AND
FANS."
Sealed the 28th May 1869, and dated the 4th December 1868.
PROVISIONAL SPECIFICATION left by the said Matthew Piers Watt
Boulton and John Imray at the Office of the Commissioners of
Patents, with thier Petition, on the 4th December 1868.
We, MATTHEW PIERS WATT BOULTON, of Tew Park, in the County of
Oxford, Gentleman, and JOHN IMRAY, of Westminster Bridge Road, in
the County of Surrey, Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN ROTARY PROPELLERS, PUMPS, AND FANS," to
be as follows:-
Our Invention relates to rotary apparatus for the propulsion of vessels,
our object herein being to construct propellers capable of as easy
reversal as the screw or the paddle, and of superior efficiency. It also

page_text: relates to rotary apparatus, of a similar kind for pumping or forcing
liquids, or aeriform fluids.
One form of propeller constructed according to our Invention is as
follows: We mount a wheel on an axis transverse to the length of the
vessel. This wheel consists of a central disc or cylindrical core furnished
with blades projecting from it, and works freely within a cylindrical
casing. On either side of the wheel are guiding passages, two sides or
boundaries of which are portions of cylinders, the outer one being a con-
tinuation of the cylindrical casing in which the wheel works, while the
inner one is of the same diameter as the disc or cylindrical core of the
wheel. Each of these guiding passages is open on one side to the blades
of the wheel, so as to afford a free passage for the water to them, and is
bounded on the opposite side by a helical surface, making one entire
revolution, these helices being of equal pitch. The positions of the
helical guides and the width of the space between them in which the wheel
works are so adjusted that if one of the helices were prolonged with a
uniform curvature it would join the other and form a continuous screw
thread throughout. The guiding passages thus formed are united
tangentially with passages directed fore and aft respectively which open
into, the outer water as directly or conveniently as possible. We prefer
to give to these passages and to, their mouths a rectangular section of
uniform area. The mouths may be placed in a direct line fore and aft
at the opposite extremities of a projecting piece. Or they may be
formed in a hollow keel. The blades of the wheel are portions of helical
surfaces. We make these of uniform pitch in order that the velocity of
the water may not be changed in passing through them; and we set
them at such an inclination that the water delivered to them by the
helical guide in a course parallel to it shall glide along and between
them without shock. This inclination is determined on the principles
well understood and commonly used in determining the inclination of
the entering edges of the blades of the wheels of turbines, which are
inclined so that the water issuing from the guides. shall glide along or
between them without shock. When the blades are small and numerous
they may be planes, having an inclination to the axis as nearly similar as
possible to that of the helical blades previously described. When the
obliquity of the helical guides is small the inclination of the blades to
the axis is also small, and in such a case plane blades parallel to the axis
may be employed with little disadvantage. When the wheel is caused
to rotate water enters by the one mouth, flows onwards into the guiding

page_text: passage previously described, where it is guided helically by the helical
side to the blades of the wheel, passes on through the wheel, continuing
uniformly its helical course, and after quitting the wheel is guided in the
same course by the other helical guide to the passage leading to the
other mouth through which it is discharged. When the wheel revolves
in the one direction it tends to create a stream backwards, and thus an
unbalanced pressure is produced, urging the vessel forwards; when the
wheel rotates in the opposite direction the direction of the stream and
of propulsion is reversed.
In the apparatus above described the water is discharged aft in a
straight stream devoid of vortical movement; it flows through the
instrument with uniform velocity and glides between the blades of the
wheel without shock. These conditions being fulfilled the principal
causes of defective efficiency in propellers are avoided. Instead of simple
helical guides guiding the water helically to and from the wheel other
forms of guides may be used. Thus the guiding passages may vary in
radius, having a spiral curvature, so that the water in passing through
them is guided radially inwards or outwards, as well as helically. In
this case we give a curved outline to the section of the wheel, so that the
water in passing through it changes its direction to and from the axis
gradually. In order that the water may flow with uniform velocity we
make the passages in the wheel of constant sectional area, and make the
blades of the wheel portions of screws of uniform pitch or planes. The
inclination of these is determined as previously explained, so that the
water may glide between them without shock. Again, the passages
leading to and from the wheel may be curved, so that the water enters
and is discharged at the outer mouths parallel to the axis of the wheel.
And numerous guiding passages curved in this way may be employed.
In order to make these passages of constant sectional area so that the
water may flow through them with uniform velocity, we so shape the
casing and core between which they are placed that the annular space
between these increases as the passages become more inclined to the
axis.
When this construction is used the wheel works with its axis
parallel to the length of the vessel.
Propellers constructed as above described may be placed in various
positions in the vessel, and pairs of them, or greater numbers of them,
may be employed. They may work entirely submerged or partly so.

page_text: Instruments of similar construction may be applied to the propulsion of
vessels moving through the air.
The various instruments above described as propellers may be used as
pumps for pumping or forcing fluids for general purposes. They may be
used for pumping liquids, or for producing blasts of air as fans. When
they are used for forcing against pressure we sometimes cause the stream
issuing from them to pass into a gradually enlarging channel in which
its velocity is reduced and its pressure raised. Otherwise we cause the
stream to pass through a succession of cylindrical passages of suc-
cessively enlarged areas, in passing through which the same effect is
produced.
Having thus described the nature of our Invention and in what
manner the same is to be performed, we would have it understood
that we do not limit ourselves to the precise forms of apparatus herein-
before described as details cf construction may be varied without
departing from the principles of construction and action which we have
above explained.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Matthew Piers Watt Boulton and John Imray
in the Great Seal Patent Office on the 4th June 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, MATTHEW
PIERS WATT BOULTON, of Tew Park, in the County of Oxford, Gentle-
man, and JOHN IMRAY, of Westminster Bridge Road, in the County of
Surrey, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of December, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Matthew Piers Watt Boulton and
John Imray, Her special licence that we, the said Matthew Piers Watt
Boulton and John Imray, our executors, administrators, and assigns, or
such others as we, the said Matthew Piers Watt Boulton and John
Imray, our executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter

page_text: during the term therein expressed, 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
"IMPROVEMENTS IN ROTARY PROPELLERS, PUMPS, AND FANS," upon the con-
dition (amongst others) that we, the said Matthew Piers Watt Boulton
and John Imray, onr executors or administrators, by an instrument in
writing under our, or their, or one of their hands and seals, should par-.
ticularly 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 Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said Matthew Piers Watt Boulton
and John Imray, do hereby declare the nature of our said Invention,
and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
Our Invention relates to rotary apparatus for the propulsion of vessels,
our object herein being to construct propellers capable of as easy
reversal as the screw or paddle and of superior efficiency; it also relates
to rotary apparatus of a similar kind for pumping or forcing liquids or
aeriform fluids.
One form of propeller constructed according to our Invention is as
follows: We mount a wheel on an axis transverse to the length of the
vessel; this wheel consists of a central disc or cylindrical core furnished
with blades projecting from it, and works freely within a cylindrical
casing. On either side of the wheel are guiding passages, two sides or
boundaries of which are portions of cylinders, the outer one being a
continuation of the cylindrical casing in which the wheel works, while
the inner one is of the same diameter as the disc or cylindrical core of
the wheel. Each of these guiding passages is open on one side to the
blades of the wheel, so as to afford a free passage for the water to them,
and is bounded on the opposite side by a helical surface. The positions
of the helical guides, and the width of the space between them in which
the wheel works, are so adjusted that if one of the helices were prolonged
with a uniform curvature it would join the other and form a continuous
screw thread throughout. The guiding passages thus formed are united
tangentially with passages directed fore and aft respectively, which open
into the outer water as directly or conveniently as possible. The mouths
may be placed in a direct line fore and aft at the opposite extremities of

page_text: a projecting piece; or they may be formed in a hollow keel. The blades
of the wheel are portions of helical surfaces, or when they are small and
numerous they may be planes; in either case their inclination is
determined on the principles well understood and commonly used in
determining the inclination of the entering edges of the blades of the
wheels of turbines, which are inclined so that the water issuing from
the guides shall glide along or between them without shock. In some
cases blades parallel to the axis may be employed with little dis-
advantage. When the wheel is caused to rotate water enters by the one
mouth, flows onwards into the guiding passage previously described,
where it is guided helically by the helical side of the blades of the
wheel, passes on through the wheel, continuing its helical course, and
after quitting the wheel is guided in the same course by the other helical
guide to the passage leading to the other mouth through which it is
discharged. When the wheel revolves in the one direction it tends to
create a stream backwards, and thus an unbalanced pressure is produced
urging the vessel forwards; when the wheel rotates in the opposite
direction the direction of the stream and of propulsion is reversed.
Instead of simple helical guides guiding the water helically to and from
the wheel other forms of guides may be used; thus the guiding passages
may vary in radius having a spiral curvature, so that the water in passing
through them is guided radially inwards or outwards as well as helically.
In this case we give a curved outline to the section of the wheel, so that
the water in passing through it changes its direction to and from the axis
gradually.
Propellers constructed as above described may be placed in various
positions in the vessel, and pairs of them or greater numbers of them
may be employed. They may work entirely submerged or partly so.
Instruments of similar construction may be applied to the propulsion of
vessels moving through the air.
The various instruments above described as propellers may be used as
pumps for pumping or forcing fluids for general purposes; they may be
used for pumping liquids or for producing blasts of air as fans. When
they are used for forcing against pressure we sometimes cause the stream
issuing from them to pass into a gradually enlarging channel in
which its velocity is reduced and its pressure raised; otherwise we
cause the stream to pass through a succession of cylindrical passages of
successively enlarged areas in passing through which the same effect is
produced.

page_text: DESCRIPTION OF THE DRAWINGS.
Fig. 1 represents a longitudinal and Fig. 2 a transverse section;
Fig. 3 a side elevation; and Fig. 4 a plan of an instrument constructed
according to our Invention.
a is a wheel fixed on a shaft b which passes through the sides of the
instrument and is caused to revolve by any convenient prime mover in
suitable bearings formed in those sides; c, c, are blades fixed on the
periphery of the wheel a; these blades may be portions of helical
surfaces, or when they are small and numerous they may be planes
inclined to the axis of the wheel as above described. The blades are
made of such size as to work freely in a cylindrical casing d which is
bounded on either side by helical surfaces e, e¹. The guiding passages
thus formed within the casing are united tangentially with inlet and
outlet passages f, g. When the wheel is caused to rotate in the direction
of the arrow marked in Fig. 1 water enters by the inlet passage f, flows
onward by the guiding passage of which the helical surface e forms the
side, and is thus guided to the blades c between which it passes, and on
leaving which it is guided by the other helical passage e' to the outlet
passage g; when the wheel revolves in the opposite direction the courso
of the stream is reversed. In an instrument constructed as above
described the casing is conveniently made in two equal and similar parts
bolted or otherwise secured together in the middle, the width of the
casing being such that the passage for the fluid forms a continuous
screw thread with two complete turns within it. Instead of making the
fluid thus take two complete turns within the easing it may be made to
take more or less by properly adjusting the width of the casing and the
positions of the tangential passages fand g. In some cases, as when the
instrument is applied to pump or force sewage, it is convenient to have
considerable clearance between the blades of the wheel and the sides of
the helical casing; this is obtained by making the width such that the
fluid in its course through the guiding passages and wheel makes more
than two helical turns.
Fig. 5 represents a transverse section of an instrument constructed so
as to give three complete turns within the casing. The obliquity or
pitch of the helical sides e, e¹, is the same as in Figs. 2 and 4, but these
sides are farther apart by a distance equivalent to the width of the fluid
passage of inlet or outlet, and therefore equivalent to the lateral distance
moved over by the fluid in one helical turn; by this construction the

page_text: blades c which may be of the same width as in Fig. 2 have greater room
on either side of them, so that solid matters have freedom to pass along
with the fluid through the instrument.
Having thus described the nature of our Invention, and in what
manner the same is to be performed, we would have it understood that
we do not limit ourselves to the precise forms of apparatus herein-before
described, as details of construction may be varied without departing
from the principles of construction and action which we have above.
explained.
In witness whereof, I, the said John Imray have hereunto set
my hand and seal, this Second day of June, in the year of our
Lord One thousand eight hundred and sixty-nine.
Witness,
ALEX. P. WRIGHT,
Secretary to the
JOHN IMRAY. (L.S.)
Inventors' Patent Right Association, Limited.