Improvements in the Arrangement of Propellers or their Equivalents for Use as Fans, Air-propellers, and similar Apparatus for Moving Air, Fluids, and Gases for Ventilating and other Purposes, and in the Manner of Revolving such Apparatus.
Year: 1888

page_text: Date of Application, 5th Dec., 1888
Complete Specification Left, 31st Aug., 1889-Accepted, 5th Oct., 1889
PROVISIONAL SPECIFICATION.
Improvements in the Arrangement of Propellers or their Equivalents
for Use as Fans, Air-propellers, and similar Apparatus for Moving
Air, Fluids, and Gases for Ventilating and other Purposes, and in
the Manner of Revolving such Apparatus.
I, CLARENCE WILLIAM CROSSLEY of St. Mary's Chambers St. Mary Axe in the
City of London Engineer do hereby declare the nature of this invention to be as
follows:-
My invention relates to certain improved arrangements of two or more pro-
pellers similar to those employed and known under the generic term of screw-
propellers for the propulsion of vessels-for use as fans air-propellers and similar
apparatus for the movement of air fluids and gases and to a method of revolving
such apparatus whereby the cost of making is materially lessened especially in cases
where they are of comparatively small size.
In one method of carrying into practice iny invention I take two propellers similar
to those used for propelling vessels but of lighter construction. The surfaces of the
blades of the propellers may be flat curved helicoidal or any other suitable shape for
giving propulsive effect axially to the medium in which they may be working. Each
propeller may be made out of one plate or disc of sheet metal or the like or the blades
may be of sheet metal or the like suitably attached to bosses or their equivalents.
There may be as many blades to each propeller as can be conveniently employed but
three for each will be found a very convenient number to use. The blades instead of
(as is frequently but not always the case with ship propellers) being perpendicular or
thereabouts to the line of shaft as seen from the side must for use in this method of
carrying out my invention be inclined thereto so as to make an angle of say sixty
degrees more or less with the shaft when viewed from the position just mentioned.
Two propellers of the kind referred to with their bosses truly bored are placed on a
tubular shaft or sleeve in such a manner that supposing each of them to have their
blades at the same inclination to the shaft the top part of the blades of one propeller
will be towards the top part of the blades of the other propeller and the roots of the
blades of the one away from the roots of the blades of the other. In other words
the blades of one propeller when thus placed and seen from the side will incline
in the opposite direction to those of the other propeller so that the tops of the blades
of one propeller will be nearer the tops of those of the opposite propeller than are the
roots of the one set of blades to the roots of the other set.
The two propellers are then moved towards one another so that the top parts of
the blades of the one propeller pass through the spaces between the blades of the
other propeller and vice versa. The blades of the two propellers will then as seen from
the side appear to cross one another at a point at a greater or less distance from the
axis according to their inclination and the distance the tops of one set of blades are
passed through the spaces between the other set, and consequently the tops of the
blades inclined in one direction will appear to be more or less over the roots of the
blades inclined in the opposite direction. The propellers are now fastened in their
respective places on the tubular shaft or sleeve and a pully or its equivalent is also
attached thereto.
Another method of proceeding would be to employ two propellers one of them
having its blades perpendicular and the other its blades inclined to the axis as
described and to pass the inclined blades through the spaces between the upright
blades so that the tops of the inclined blades would be in advance of the upright
blades and the roots of them behind the upright blades. Three or more propellers
might also be used some of them with inclined blades and others with upright
blades.

page_text: Instead of using separate propellers in the manners mentioned, the blades might be
all fastened on one boss either 1st. In the relative positions to one another above
described or 2ndly. So that inclined..blades will alternate with upright ones or blades
inclined in one direction with those inclined in the opposite direction. The roots of
the blades in the latter arrangement revolving more or less between two planes and
not between more than two planes as in the first described method.
In whatever way the blades may be arranged on the boss or bosses carrying them,
the tubular shaft or sleeve above referred to, being truly bored out is slipped over an
inside shaft of sufficient outside diameter to allow the tubular shaft and what is
attached to it to revolve round it without shake. The inside shaft is then fastened
(generally at each end) in what-if it revolved in the usual way-would be journals
and the journals or equivalent are fastened to arms which in their turn are attached to
a ring or the like or are otherwise supported so as to be readily fastened in their
required position for work.
In this method of driving it will be seen that the propellers and pully on a tubular
shaft revolve round a non-revolving inside shaft instead of being attached directly to
a shaft revolving in journals as hitherto. By this means a great part of the difficulty
of getting the axis of the shaft in true line with axis of bearing is done away with.
The boss or bosses for the propeller blades as well as the pully and the tubular shaft
may if desired be all cast or otherwise made in one piece so as to still further reduce
the cost of fitting.
The method of driving above described is applicable to fans air-propellers and
similar apparatus having blades arranged otherwise than as described in this
specification.
In my improved method of driving herein described the inside shaft itself may be
tubular also or for a part of its length and have holes to allow the escape of lubricant
for lubricating the inside of the revolving tubular shaft the lubricant being
supplied from a cup or cistern at the end or ends of the inside shaft. In fact the
parts in which the ends of the inside shaft are fastened might be made hollow to serve
as reservoirs for the lubricant.
Although I prefer the above method of driving the apparatus by means of a
tubular shaft revolving round an internal one especially in the case of small fans
etc., etc., on account of the reduction in cost of fitting up etc., nevertheless if preferred
(and in the case of large fans or where cost of making is of no great consequence it
might be so preferred) the propellers or sets of blades and the bosses together with
the pully can be attached directly to a shaft or spindle revolving in journals in the
ordinary manner.
Although I do not confine myself to any particular form of blade I prefer it to be
such that the circle on which any two blades would cross each other if in contact
would have a radius about two thirds the radius of the apparatus measured from the
centre of rotation without necessitating the placing of the roots of the respective sets
of blades too-far apart.
One or more of the propellers or sets of blades may be what is known as
< right
handed" and the other left handed" as regards the direction of rotation or they
may all be right or left handed in any case they may be of the same or different
pitches. The propellers or blades all revolve in one direction.
One or more of the propellers or sets of blades can be wholly or partly surrounded
by or enclosed in a ring or short cylinder or cone or the like which may revolve
with the apparatus or remain stationary.
In using two propellers or sets of blades I should prefer generally to surround one
or both of them by a ring or short cylinder of greater or less width than the space
between the leading and following edges of the peripheries of each set of blades or it
might be of the same width as that space.
From the above description it will be seen that my invention relates primarily to the
arrangements of the propellers or blades as regards their positions towards one another
and the axis and secondly to the method of driving thein-and not to the particular
form of the blades themselves which may be of any suitable shape or curvature. I

page_text: have however indicated my preference for such a form as would allow the blades to
cross at about two-thirds the radius from the axis without taking up too much room
on the shaft.
Dated this Th: 1 D 1000
COMPLETE SPECIFICATION.
Improvements in the Arrangement of Propellers or their Equivalents
for Use as Fans, Air-propellers, and similar Apparatus for Moving
Air, Fluids, and Gases for Ventilating and other Purposes, and in
the Manner of Revolving such Apparatus.
I, CLARENCE WILLIAM CROSSLEY of St. Mary's Chambers 14 St. Mary Axo in the
City of London Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
My invention consists in certain arrangements of two or more propellers or sets of
blades (similar to those employed under the generic term of screw-propellers for
propelling ships) for use as fans, air-propellers and similar apparatus for the move-
ment of air fluids and gases for ventilating and other purposes, and to a method of
revolving apparatus of this and other construction, whereby the time occupied in
making and fitting up is materially lessened especially in cases where they are of
comparatively small size. In this Specification I make reference to the accompanying
drawing in which similar letters generally represent similar parts.
*
In one method of putting into practical shape my invention I take two propellers
similar to those used for propelling vessels, but of lighter construction. The surfaces
of the blades of these propellers may be flat, curved, helicoidal or any other suitable
shape, but they must be disposed at an angle on their bosses, as regards the direction
in which they are revolved, in order to give them what is technically known as a
pitch," so that by revolving them an axial propulsive movement will be given to the
air or other medium in which they are revolved. Each propeller may be made out
of one plate, sheet, or disc of metal, or other suitable material; or the blades may be
made separately and suitably attached to bosses or their equivalents. Each propeller
may have as many blades as can conveniently be used, but three for each propeller
will be found a very good number to use.
The blades, instead of standing perpendicular, or thereabouts, (as is often, though
not always, the case with ship propellers) to the line of shaft as seen from the side,
must, for use in the method of carrying out my invention now being described, be
inclined thereto, so as to make an angle of sixty degrees (more or less) with the
shaft when viewed from the side as just mentioned.
Fig. 1, of the accompanying drawing shows at a, b, c, d, e, side views of various
propellers with blades of suitable shape for the purpose of this Invention: other
shapes can be used, but those shown are very suitable ones and of these I prefer a
shape similar to a, or b.
Two propellers, similar to those referred to, and having a suitable number of blades
attached to bosses which have been bored out, are placed on a tubular shaft in such a
manner, that the tops of the blades of one of the propellers, will be towards the tops
of the blades of the other propeller, and the roots of the blades of the one propeller,
away from the roots of the blades of the other propeller. In other words, the blades
of one propeller when thus placed and when viewed from the side will incline in the
opposite direction to those of the other propeller, so that the top parts of the blades
of the one propeller will be nearer the top parts of those of the opposite propeller
than are the roots of the blades of the one to the roots of the blades of the other
propeller. See Fig. 2 of the drawing where f, g, shews in dotted lines' this
first position of the two propellers; ; i, being the respective bosses, and k, the
tubular shaft.

page_text: The two propellers are then moved towards one another so that the blades of the
one propeller pass through the spaces between the blades of the other propeller. The
blades of the two propellers will then, when looked at from the side, appear to cross
one another at a point at a greater, or lesser distance from the axis of the tubular
shaft according to their inclination and the extent to which the blades of the one
propeller are passed through the spaces between the blades of the other propeller:
consequently the tops of the blades inclined in the one direction will appear to be
more or less over or beyond the roots of the blades inclined in the opposite direction.
See the two propellers fand g, shewn in full lines in Fig. 2.
The propellers are now to be fastened in their respective places on the tubular
shaft by keys, set-screws, or other convenient means, and a pully or spur, bevel, or
friction wheels, or other suitable appliance, is also attached to the shaft by which to
revolve it.
The tubular shaft having been truly bored out, (either previously or subsequently
to the putting on of the propellers) is slipped over an inner shaft, or spindle of such
a length, as to project at each end of the tubular shaft, and of such an outside
diameter, that it will allow the tubular shaft and what is attached to it, to revolve
round it easily and without shake or unnecessary friction. See Fig. 3. where f, g are
the propellers; h, i, the bosses; the tubular shaft; 'the inner shaft or spindle
round which can be easily revolved; and m, a pully for revolving the tubular shaft.
Collars n, n, are placed on the shaft l, to keep the tubular one k, from sliding out of
its place on shaft 1.
وو
The shaft I, is then fastened (generally at each end) so that it cannot revolve, in
what, (if it did revolve in the ordinary manner) would be "bearings as at o, o,
Fig. 3, where the shaft is shewn as fastened by set screws: these supports o, o, may
have formed on, or attached to them, two or more "wings" similar to those shewn
at p. p. Fig. 3. These wings may now be fastened to arms, (curved so as to clear
the blades of the propellers: the other end of each arm is also fastened to a ring
rather larger in inside diameter than the diameter of the circle which the tips of the
blades describe during their revolution. The ring would have bolt-holes in it, to take
bolts for fastening it into position in the manner usually adopted in fitting up Air-
propellers, ventilating fans and similar apparatus. Instead of being fastened to a ring
as just mentioned, the arms at their outer ends may be attached to a drum, short
cylinder, or the like wholly or partly surrounding the peripheries of the blades; or
any other means may be used for supporting the apparatus whereby it can be readily
fastened into the wall, ceiling or other position for work.
To reduce friction as much as possible, the tubular shaft may be bored out rather
large, and a bush or short lining put in at each end to prevent contact between the
inside of the tubular shaft and the outside of the inner shaft, except where these bushes
or linings may be two such bushes are shewn in section at qg Fig. 3. Another
mode of proceedure would be to turn down the diameter of the inner shaft 7, here and
there, so that it can only touch the inside of the tubular shaft at a few places instead
of all along.
It will be seen that in this method of revolving the apparatus, the propellers,
pully, etc. fixed on a tubular shaft, are made to revolve round a non-revolving inner
shaft or spindle (passed axially through the tubular shaft), instead of being directly
attached to a shaft revolving in bearings in the ordinary way. A large part of the
time usually occupied in getting the axis of the shaft in line with the axis of the
bearing is thus done away with.
Fig. 4 of the accompanying drawing, shews a section through u, u, of Fig. 3, and
exhibits a front view of the two propellers. The blades of the propellers are cut
from sheet-metal, and are represented as having strengthening pieces v, v, of wrought
or cast metal fastened to them and extending from the boss to near the periphery of
each blade. This Fig. represents the blades as being further prevented from bending
over, or losing shape during rotation, and this is done by using
"
stays
"ties" w, w. These " stays
are connected to the outer part of the blades at one
end, and at the other end are screwed or otherwise fastened to, or into the bosses, as
די
or

page_text: will be seen from Fig. 3. The " stays" may be made of iron or steel rods or the
like, or of any other metal, and they may be conveniently fastened to the blades in
the following way :-The end of the stay is screwed for a short distance and a nut put
on a hole having been made through the blade at the proper place, the outer part
of the screwed end of the stay is put through it, and another nut screwed on to keep
the blade in place between the nuts.
Fig. 51, 52, and 53 shew more in detail one mode of fastening blades and g, to the
bosses Fig. 5 being a front view, Fig. 52 a plan of the boss, and Fig. 5 the root of
one of the blades. The boss is made with notches ., ., across it at such an angle as
will give the necessary propelling "pitch" to the blades at this point. The extreme
ends y, of the blades are put into these notches, and the strengthening pieces v, being
turned away from the blades as shown at , are placed in the channels 21, sunk in
the bosses, and are further secured by one or more bolts as shewn at of Fig. 51.
The inside of the tubular shaft may be lubricated in any suitable manner; for
instance, the collars n, Fig. 3, might be hollowed out to form small reservoirs for the
lubricant supplied through a lubricator or cup. The lubricant would pass from these
hollowed collars to the space between the tubular shaft and the inner one. See
Fig. 3. where r, represents the hollow in the collar, and the lubricator. A spiral
groove could be cut in the inner shaft or spindle, to convey the lubricant and
distribute it over the inside of the tubular shaft: see t Fig. 3. Another method of
lubricating would be to make the inner shaft l, tubular also, for the whole or a part of
its length, and to provide it with holes, so that the lubricant can escape inside the
revolving tubular shaft: the lubricant being supplied from a cup, cistern or other
source at one end or both ends of the inner shaft 1. In fact, the supports o, o, in
which the ends of the inner shaft are fixed, might be made hollow to serve as
reservoirs for the lubricant. See Fig. 6, where k is part of the revolving tubular
shaft, n, one of the collars for keeping it in position, 1, the inner non-revolving shaft
bored out, or otherwise made tubular and provided with holes 1, 2, 3 etc. and fastened
into o the cavity r, may be "charged" with lubricant supplied by the lubricator
fixed as at s, or as at s¹. By this method the lubrication could be effected altogether
from one end of the shaft.
In the above described method of driving or revolving air-propellers, etc., by a
tubular shaft revolving round a non-revolving inner shaft or spindle, the bosses or
boss for the propeller blades, together with 'the pully and tubular shaft, may all be
cast or otherwise made in one piece, thus still.further reducing the cost of fitting.
The method of revolving substantially as herein described is applicable to the
driving of air-propellers, ventilating fans, and similar apparatus, of other construction
than any described in this specification.
Although I prefer this method of revolving for use with the various combinations
and arrangements of propellers herein described and exemplified in the drawings,
especially when the apparatus is of comparatively small size, nevertheless, any of
the combinations, etc., can be attached directly to a shaft or spindle revolving in
bearings in the ordinary manners already in use.
Another method of combining or arranging the propellers, or blades, would be to
employ two propellers, one of them having its blades perpendicular to the boss, and
the other having them inclined thereto as already described. The two propellers
being placed on a shaft as before mentioned, are then arranged so that the inclined
blades of the one pass through the spaces between the upright blades of the other:
thus arranged, the tops of the inclined blades will be in advance of the tops of the
perpendicular blades, and the roots of them in the rear of the roots of the perpen-
dicular ones.
See Fig. 7. which is a side view of two propellers so arranged.
Instead of using separate propellers each with its separate boss and number of
blades and putting them in position on the shaft as already described, the blades may,
instead, be at once fastened (in the relative positions to each other herein set forth)
on one boss. In using only one boss, the blades may also be so disposed, and fastened
round it, that inclined blades alternate with perpendicular ones, as exemplified in

page_text: Is a Sme view of three sets of blades 1. 2. 5 or blades inclined in one
direction may alternate with those inclined in the opposite direction, as exemplified at
1 and 2 in side view Fig. 9, and front view Fig. 9. Fig. 10 shews three propellers,
two of them with blades inclined to each other, and one of them with perpendicular
blades the two former (1 and 2) have two blades to each propeller, and the latter (3)
has four blades, but any other number may be used. It will be seen by Figs. 8, 9
and 9', that in the arrangements to which those Figs. relate, the leading and trailing
edges of the roots of the blades revolve between two planes, whereas the outer parts
(or tops) revolve between four or more planes according to the number of propellers
or blades used. Fig. 11 is a front view of Fig. 8.
One or more of the propellers or sets of blades used in carrying out my Invention,
may be what is technically known as "right-handed," and the other or others, or
some of them may be "left handed," but I generally prefer them to be all "right
handed," or else all "left-handed:" in any case they may be of the same or different
"pitches." The propellers, or sets of blades are all to be revolved in one direction,
towards the right or left according as they are right- or left-handed.
The blades instead of being fastened to the boss or bosses radially as seen from the
front and indicated in the drawings, may be fastened more or less tangentially
thereto.
Although I have shewn certain forms of blades in the drawings, nevertheless, I do
not confine myself to the use of any particular form of blade, but I prefer it to be
such that the point at which any two blades would cross each other (if revolved on
the axis of the shaft, so as to bring them in contact) would be situated at about two
thirds of the radius of the whole apparatus, measured outwards from the axis of
rotation; or one third measured inwards from the periphery.
In any of the arrangements or combinations of blades or propellers made use of in
carrying out this Invention, the periphery or peripheries of the blades of one or more of
the propellers or sets of blades may be wholly or partly surrounded by a cylinder
ring or band, attached to the blades and revolving with them. See Figs. 16" and
16 of the accompanying drawing, which shew side views of two propellers or sets of
blades so surrounded. In each of these Figs. the blades are marked 1. 2: the
periphery of the propeller or set of blades 1, is surrounded by a ring of which
7, 8, 9, 10 is a side view, and the periphery of the propeller or set of blades 2, is
surrounded by a ring of which 3, 4, 5, 6 is a side view. It will be noticed that in
Figs 16" and 16, only the peripheries of, and not the spaces s between the propellers
or blades, are surrounded by the rings: but if desired the spaces s, may also be
surrounded, and one broad ring or cylinder extending from 3, 5, to 8, 10, might be
used. In any case the ring or rings, or cylinder or cylinders may have apertures
made in them so as to allow some air to enter at the periphery. The diameter of 3, 5,
or 7, 9, of the rings may be greater or less than the diameter of 4, 6 or 8. 10.
As to the construction of the propellers used for carrying out this Invention, they
may be made in any convenient and suitable manner, for instance, they may be cast:
but for general purposes, if thus made they would probably be too heavy. It
would be better to make the blades of sheet metal and fasten them to suitable bosses,
by bolts, set screws and the like. Any required curvature may be given to the
surface of the blades by hydraulic, or other pressure, by hammering, or by other
means, and this may be done previous to fastening them to the boss or afterwards.
I have already indicated one mode of construction in connection with Figs. 3, 4
and 51, 52, 53. Figs. 12', 12, 123 124, shew various views of another kind of boss
for two or more blades; these bosses have notches x, x, across them into which the
ends of the blades are placed & fastened by bolts or the like passing through the
blades as at 3, into the projection 2. The blades are cut from sheet metal or
the like, of some such form as shewn in Fig. 13 a. b. c. d. The surfaces of the blades
may be curved helicoidly or otherwise or they may be kept perfectly flat, and placed
in a notch, at such an angle as.will give them a pitch," and consequent pro-
pelling power when revolved.
"

page_text: Fig. 14 indicates a further method of constructing a propeller. A piece of sheet
metal or the like is cut out, or joined up, so as to have a form similar to a, b, c, d, e,
f, g, h, i, which represents three blades. Each blade is then bent and curved on
lines radiating from one corner, say i (of the blade f, g, h, i) substantially as shown
by the dotted lines i, 2, 3, etc. After being so bent the edge f, g, will no longer be
in the plane of the centre i, e, f (which was also the plane of the blades previous to
their being bent in any way) but will be found to curve away from that plane as
exemplified at a, b, c, Fig. 15, which is a side view. A blade after being bent and
curved as thus described, will appear similar to a, b, c, i of Fig. 14. when seen from
behind. Fig. 14" shews a plan of one of the blades after bending,-i. c. representing
the plane of the centre and a, b, shewing the kind of curve which the bending should
finally give to the blades. Fig. 14 shews (on a larger scale) a section across a blade
say at a, b, Fig. 14. The arrow 1, indicates the direction in which the blade should
revolve in order to propel the air, etc., in the direction of the arrow 2. Fig. 14º,
shews a section through a line joining i and , Fig. 14. All the blades of a propeller
made as just described should be bent in a similar manner: the blades should also
23
have " stays or "ties" similar to those described, and shewn in Figs. 3 & 4 to
prevent them getting out of shape during rotation. The propeller must have a hole
made in the centre for the shaft, and it will generally require to be fastened to some
kind of casting or the like, such as Fig. 15, so that it can be more readily attached
to the shaft. Propellers with more or less than three blades can be constructed in
the manner above described.
For use in any of the combinations or arrangements mentioned herein, propellers
can also be made by riveting or otherwise fastening the blades to a rod or bar passing
up the back of the blade, the end of the rod or bar being screwed into the boss so as
to bring the blade to the proper propelling angle. I sometimes only use a portion
of the blades instead of the whole of it, the length of blade being, say, about one half of
the radius of the machine measured inwards from the periphery towards the axis, the
other part being cut away; and the part which remains is attached to a rod or bar,
as mentioned. See Fig. 17 which is a side view, and shews at a and b, two arrange-
ments of blades made as just mentioned: c, d, in each case are the rods screwed into
the boss e or f, and riveted to the "parts" of the blades 9, h.
I do not confine myself to the precise shapes, configurations, positions, curvatures,
bends, number of blades, relative proportions, or to any other detail whether described
in this specification or exemplified in the drawings, as it will be readily seen that
several of such details may be considerably varied without departing from the
Invention.
Having now particularly described & ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what 1
claim is :-
1. The manufacture of the following combinations and arrangements of propellers,
perpendicular and inclined blades or their equivalents, and the use of the combinations
and arrangements as Fans, Air-propellers, and similar apparatus for moving air, fluids
and gases, for Ventilating and other purposes; that is to say:
(a) Two propellers or sets of blades, the blades being of such form and the
propellers or sets of blades being so fastened to bosses or a boss and so placed
on a shaft or spindle as regards one another, that when the axis of the two
propellers or sets of blades are coincident with the axis of the shaft, the
blades of one of the propellers or sets of blades will be more or less through
the spaces between the blades of the other propeller or set of blades, sub-
stantially as described in this specification and exemplified by Figs. 1, 2, 3
and 4 of the accompanying drawing; and any mere modification or imitation
of such combination.
(b) Two propellers or sets of blades, one of them baving inclined blades which
are passed through the spaces between the perpendicular blades of the other
propeller, or set of blades, substantially as described in this specification and

page_text: exemplified by side view Fig. 7 of the accompanying drawing; and any mere
-modification or imitation of such combination.
(c) Several perpendicular and inclined blades fastened round a boss. so that
inclined blades alternate with perpendicular ones, substantially as described in
this specification and exemplified by 1 and 3 of Fig. 8, of the accompanying
drawing and any mere modification or imitation of such arrangement.
(d) Several perpendicular and inclined blades fastened round a boss, so that a
blade inclinéd in one direction (as seen from the side) is followed by one
fastened perpendicularly, which in its turn is followed by one inclined in the
opposite direction (as seen from the side) to that of the first, and so on all round
the boss substantially as described in this specification and exemplified by
1, 2, 3 of Fig. 8. of the accompanying drawing, which is a side view:
and any mere modification or imitation of such arrangement.
:
(e) Several inclined blades fastened round a boss or bosses, so that those blades
inclined in one direction (as seen from the side) will alternate with those
inclined in the opposite direction (as seen from the side): substantially as
described in this specification and exemplified by 1 and 2, of Fig. 9, of the
accompanying drawing, which is a side view, and Fig. 91, which is a front
view; and any mere modification or imitation of such arrangement.
(f) Three propellers or sets of blades, the middle one having perpendicular blades,
the one in advance of it having blades inclined so that they pass through the
spaces between the perpendicular blades, while the propeller in the rear of
the one with perpendicular blades, has its blades inclined in the opposite
direction so that they also pass through the spaces between the perpendicular
blades; substantially as described in this specification and exemplified by
1, 2, 3 of Fig. 10, of the accompanying drawing, which is a side view, and
by Fig. 11 which is a front view; and any mere modification or imitation of
such combination.
2. The several combinations and arrangements referred to in the previous claim,
whether such combinations and arrangements are attached to a shaft or spindle
evolving in bearings in the ordinary manner, or whether they are attached to a
ubular shaft revolving round an inner non-revolving one, as mentioned in Claim 3
which immediately follows this one.
3. The use of the method of revolving or driving any of the combinations or
rrangements referred to in Claim 1, a, b, c, d, e, f, or any other kind of Fan, Air-
ropeller or similar apparatus, by attaching any of the said combinations, arrange-
ents or apparatus to a tubular shaft, and revolving (by pully or otherwise) the said
ubular shaft (and whatever is attached thereto) round a non-revolving inner shaft or
pindle passed axially through the tubular one substantially as described in this
pecification and exemplified by Fig. 3 of the accompanying drawing: and any mere
odification or imitation of such method of driving.
4. The use, with any of the combinations and arrangements of propellers or sets of
lades mentioned in this Specification and exemplified by the accompanying drawing,
f cylinders, rings, bands or the like, surrounding the periphery or peripheries of one
r more of the propellers or sets of blades and revolving with it or them ; sub-
tantially as described in this Specification and exemplified by Figs. 16 and 16 of
he accompanying drawing; and any mere modification or imitation thereof.
.
5. The arrangements for lubricating the inside of the revolving tubular shaft used
the mode of revolving or driving mentioned in Claim 3; substantially as described
this specification and exemplified by Figs. 3 and 6 of the accompanying drawing;
nd any mere modification; or imitation thereof.
6. The use of the method of fastening the blades of propellers to their bosses and
trengthening them by pieces v, and stays w, substantially as described in this
pecification and exemplified by Figs. 3, 4, 51, 52 and 53, of the accompanying
rawing; and any mere modification or imitation thereof.
7. The use of bosses to carry any number of blades, such bosses being made and
sed substantially as described in this specification and as exemplified in the case of

page_text: two or three blades, in Figs. 121, 123, 123 and 124; and any mere modification or
imitation of such bosses.
8. The method of constructing propellers with any number of blades, substantially
as described in this specification and exemplified in the case of three blades in
Figs. 14, 15, 14, 14° and 14° and any mere modification or imitation thereof.
9. The use in any of the combinations or arrangements described in this specification
and exemplified by the drawings, of propellers having their blades (or so much of
them as is used) attached to rods or bars screwed or otherwise fastened into bosses
or a boss substantially as described in this specification and exemplified by Fig. 17,
of the accompanying drawing; and any mere modification or imitation thereof.
10. The general arrangements and combinations of parts substantially as described
in this specification and exemplified in the accompanying drawing and any mere
modification or imitation of it or them.
Dated th:. 2011
** A 1000
CLARENCE W. CROSSLEY.