An Improved Rotary Fan or Propeller for the Movement of Air for Ventilating, Blowing, and similar Purposes, Applicable also for the Movement of Fluids and Gases.
Year: 1886

page_text: Date of Application, 27th Apr., 1886.
Complete Left, 7th Dec., 1886.
Complete Accepted, 7th Jan., 1887.
An Improved Rotary Fan or Propeller for the Movement of Air for
Ventilating, Blowing, and similar Purposes, Applicable also for
the Movement of Fluids and Gases.
I, FRANCIS JAMES CROSSLEY of 32 Meetinghouse Lane Peckham in the County of
Surrey, Joiner do hereby declare the nature of this invention to be as follows:-―
For the purpose of carrying out my Invention I take a triangular square or poly-
gonal piece of metal which forms the centre of the apparatus and the centre of which
piece of metal shall be coincident with the axis of rotation of the apparatus. To each
side of the said triangular square or polygonal piece of metal I affix a piece of sheet
metal having the form of a semi-circle segment of a circle or of a semi-heart or the
like in such a manner that in the case of using a semi-circular or segmental piece one
extremity of the diameter or chord (as the case may be) will be at the corner of one of
the sides of the said triangular square or polygonal shaped centre and in the case of
using a semi-heart shaped piece then in such a manner that its straight side shall be
on the side of the triangle square or polygon and the larger end of the semi-heart as
far from the centre of the apparatus as will permit of the extreme point of the narrow
end being on the corner of the side to which the piece is fixed & this corner being the
one farthest from the wide end of the semi-heart shaped piece of metal. Whatever
may be the shape of the affixed piece it must be of greater length than the side of the
centre to which it is attached & it must be joined to the side in such a manner that no
Each of the
part of one of the semi-circular pieces or the like overlaps another.
pieces which has thus been fixed to the sides I bend and curve inwards from the line
of junction towards the centre (the rate of curvature being uniform or varying) so
that the angle between the highest part of each upturned and curved piece and the
plane of the triangular square or polygonal centre shall contain about 145 degrees
more or less. Instead of bending each piece at the line of junction with the side of
the triangle square or polygon 1 sometimes start the curving immediately from that

page_text: point in which case the curve will be tangential to the plane of the centre. I
sometimes construct the apparatus from a single piece of metal instead of joining it
up as just described. The apparatus is fixed to a shaft or spindle running in bearings
and turned by any suitable means.
Two or more of the above described apparatus may be fastened behind in front of
or above one another on one shaft or on separate shafts revolved in different directions
and any or all of them may be wholly or partly surrounded by or encased in a cylinder
cone or ring either revolving with the apparatus or remaining stationary.
I sometimes fasten two of the apparatus on one shaft face to face with a disc between
them and enclose them in a casing of the usual description for use as a blower.

page_text: An Improved Rotary Fan or Propeller for the Movement of Air for
Ventilating, Blowing, and similar Purposes, Applicable also for
the Movement of Fluids and Gases.
I, FRANCIS JAMES CROSSLEY of 32 Meetinghouse Lane Peckham in the County of
Surrey, Cabinet Maker do hereby declare the nature of my invention for AN
IMPROVED ROTARY FAN OR PROPELLER FOR THE MOVEMENT OF AIR FOR VENTILATING.
BLOWING & SIMILAR PURPOSES APPLICABLE ALSO FOR THE MOVEMENT OF FLUIDS
& GASES and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
"
In carrying out my Invention I take a triangular square or polygonal piece of metal
or the like (I prefer sheet metal) which forms the central part of the fan or propeller
and which I shall hereinafter call "the centre." The centre of this piece of metal is
coincident with the axis of rotation of the fan or propeller. The fan or propeller I
shall generally refer to in this specification as "the apparatus." To each side of the
said centre I affix a piece of sheet metal or the like having the form of or similar to a
semi-circle, segment of a circle or of a semi-heart or the like (and which I shall in
this specification call "the blade or "blades") and I fix it in such a manner that in
the case of using a semi-circular or segmental blade one extremity of the diameter or
chord (as the case may be) will be at the corner of the side of the said (triangular,
square or polygonal shaped) centre to which it is fixed and the diameter or chord itself
coincident with the side of the centre. In the case of using semi-heart shaped pieces
or the like I fasten them so that the straight side of cach blade shall be on the side of
the centre to which it is attached and the large end as far from the centre of rotation
of the apparatus as will permit of the extreme point of the narrow end of the blade
being on the corner of the side to which the blade is fixed-this corner being the one
furthest from the wide end of the blade. Whatever may be the shape or configuration
of the blades they must be of greater length than the sides of the centre to which they
are attached & they must be so joined to the sides that no part of one blade over-
laps another. The diameter of the circle described by the corner of the triangular or
other shaped centre should be about one third that of the whole apparatus.
The blades having been thus attached to the centre I bend and curve them inwards
from the line of junction towards the centre of rotation-the rate of curvature being
either uniform or varying either in a vertical or horizontal direction or both-so that
the angle between the blades and the plane of the centre shall contain about 145
degrees more or less.
Instead of bending each blade at the line of junction with the centre before curving.
it, I sometimes start the curving immediately from that line-in which case the curve
will be tangential to the plane of the centre.
I sometimes construct the apparatus from a single plate of metal instead of joining
it up as just described and I sometimes curve the blades away from instead of towards
the centre of rotation.
The apparatus is fixed to a shaft or spindle running in bearings and turned by any

page_text: •
suitable means the direction of rotation is shown by arrows in the drawings herein-
after referred to.
I sometimes make the sides of the centre curved instead of straight and they may be
curved inwards or outwards. The blades will then be suitably cut and curved so as
to admit of their being fastened to the sides. In other cases I make the centre in the
form of a short pyramid having three or more sides-the blades being fastened to the
edges thereof as in the case of a flat centre.
In
some cases & with certain curvatures of the blades I insert a kind of gusset
(which may be triangular) between the sides of the centre and that part of the blades
which would otherwise be fastened to the sides. By this means I throw the blades
out of the plane of the centre.
Two or more of the above described apparatus may be fastened behind, in front of
or above one another on one shaft or on separate shafts revolved in different direc-
tions. Any or all of the above described apparatus may be wholly or partly surrounded
by or encased in a cylinder, ring or cone revolving with the apparatus or remaining.
stationary.
In order that my Invention may be more particularly described and ascertained
reference is hereby made to the accompanying drawings in which similar letters &
figures of reference indicate wherever possible corresponding parts. In the drawings
I have shewn an apparatus with three blades on a triangular centro & the shape of the
blades as that of a quasi-semi-heart. I do not however confine myself to that number
of blades or to that precise shape or to the particular curves or bends shewn and..
described for the purpose of explanation as it is obvious that any or all of them may
be considerably varied without departing from the invention.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 shows a front elevation of the apparatus. Fig. 2 a side elevation. Fig. 3 a
section thro' line ZZY Y on Fig. 1. Fig. 4 shews a variation in the curve of the
blade with reference to the plane of the centre. Fig. 5 shews a blade bent away from
the plane of the centre. In Fig. 1. ABC is a triangular centre to each side of which
is fixed the blades ADEC, BFGA, CHIB. The blades are bent up and curved
from the lines A B, BC, CA so that when seen from the edge they appear as shewn
in that part of Fig. 2 which corresponds to blade CHIB of Fig. 1. This supposes
the ratio of curvature to be constant: if it is made varying the view from the edge
would be slightly different. As mentioned in the former part of this specification the
curve of the blades may start at once from the plane of the centre and will thus be
tangential thereto. The apparatus is supported on a shaft or spindle K by being
attached to a suitably shaped casting such as L keyed or otherwise fastened to the
spindle K. The spindle is furnished with a pulley M in the ordinary way & runs in
suitable bearings supported as circumstances or convenience may require. In supplying
the apparatus in the ordinary way of business I support the shaft by arms attached to
the bearings the other ends of the arms being fastened to a ring having bolt-holes by
which it can be fastened in a wall or ceiling or otherwise. When it is required to turn
the machine by hand I fasten a handle (which may be removable) and sometimes
multiplying gear to the end of the spindle for that purpose. In order to propel the air
or other medium in the direction shewn by the arrows in Fig. 2. the apparatus should
be revolved in the direction shewn by the arrows in Fig. 1. but if the blades are bent
as shewn in Fig. 5-then the apparatus must be revolved in the opposite direction to
that indicated by the arrows in Fig. 1.
In order to prevent the blades flattening out by the pressure of the air during
rotation & so losing their shape & destroying their propelling power I slip over the
spindle a ring N and fasten it to the spindle with a set screw or other suitable means.
In this ring I screw or otherwise fasten the ends of the rods, bars or the like 123456
the other end of each being passed through the blades at or about the position shewn
and fastened in a suitable manner such as by inside & outside bolts. I have shewn
two of these rods to each blade but I may use more or less.
Fig. 6 shews a centre with inwardly curved sides & an apparatus constructed with

page_text: such a centro should be rotated in the direction of the arrows. Fig. 7. shews a centre
with outwardly curved sides and when an apparatus has this kind of centre it should
be rotated as shewn by the arrows of this figure.
Figs. 8 and 8 shew front and side views of a centre in the form of a short pyramid.
The sides are shewn straight but they may be curved as shewn in Figs. 6 and 7-the
remarks to which Figures as to direction of rotation apply equally well to Figs. 8* and 8°.
Having now particularly described & ascertained the nature of my said Invention
and in what manner the same is to be performed, I'declare that what I claim is :-
(1) The manufacture and use of improved rotary fans or propellers for the purposes
set forth in the title, constructed and operating substantially as hereinbefore described
and as partly illustrated by the drawings or any mere modification thereof.
(2) In the construction of my improved rotary fans or propellers the combination
with a triangular, square or polygonal flat or pyramidal centre, of blades having the
shape or configuration of or similar to a semi-circle, segment or semi-heart or the like,
the surface of each blade being curved and the sides of the centre being either straight
or curved inwardly or outwardly the whole substantially as berein before described
and as partly shewn in the drawings or any mere modification thereof.
(3) The combination with fans or propellers constructed as herein before described
of a ring, cylinder or cone, wholly or partly surrounding or encasing it and revolving
with the apparatus or remaining stationary.
(4) The general arrangement, construction & combination of the several and respec-
tive parts (or any mere modification of them) together forming my Improved rotary
fan or propeller substantially as herein before described and as partly illustrated by the
drawings.