Improvements in Screw Propellers.
Year: 1890

page_text: Date of Application, 18th July, 1890
Complete Specification Left, 1st Apr., 1891-Accepted, 23rd May, 1891
PROVISIONAL SPECIFICATION.
Improvements in Screw Propellers.
WILLIAM HOLLIS Esperance Villa, Bullars Road Bitterne Park near
Southampton late Mechanist in H.M. Service. I William Hollis do hereby declare
the nature of this invention to be as follows:-
:―
A. propeller with two blades and a band on its circumference, the angle of
blades are connected to band by fookes, the inner edge of band will connect
the edge of one blade to the end of opposite blade, this edge of band is an
eccentric curve,
the circumference of propeller being retained in the centre line
of band cutting through the ends of blades in each semi-circle, either side of
propeller corresponding with the other.
Improvements in Screw Propellers.
near
WILLIAM HOLLIS Esperance Villa, Bullars Road Bitterne Park
Southampton late Mechanist in H.M. Service. I William Hollis do hereby declare
the nature of this invention to be as follows:
A propeller with two blades and a band on its circumference, the angle of
blades are connected to band by fookes, the inner edge of band will connect
the edge of one blade to the end of opposite blade, this edge of band is an
eccentric curve, the circumference of propeller being retained in the centre line
of band cutting through the ends of blades in each semi-circle, either side of
propeller corresponding with the other.
Fig. 1 and 2, Sheets 1 and 2.
SPECIFICATIONS.
Left and right hand propeller with two blades, and a band on its circumference.
A A shows incline surface of blades.
BB shows decline surface of blades.
CC shows the acute angle flookes, connecting the rear angle of blades to the
inner surface of band F F.
DD shows the obtuse angle flookes connecting the prominent or front angle of
blades A B to the band E E.
EE is the external surface of band, the circumference of propeller is retained
in centre line of band, cutting through the ends of blades.
FF is the internal surface of band, the edges of band are eccentric curves,
connecting the edge of one blade to the end of opposite blade, terminating in the
circumference in each semicircle, and on either side of propeller.
GH the apertures or spaces within the blades and band.
II the hub or boss.
Fig. 3 and 4, Sheet 1 and 2.
The section of propeller cutting through the diameter 11.
A B shows the section of blades cutting through the diameter line.
DD is the obtuse angle flookes connecting the surface of blades A and B to the
external surface of band E E.
E E the external face of band forming a continuous surface over flookes D D
with the surface of blades A and B giving an uninterrupted surface from face of
blades to the external surface of band.
F F shows internal surface of band.
Fig. 5 and 6, Sheets 1 and 2.
Shows the perpendicular section of propeller 2 2 cutting at right angles from the
diameter line 1 1.
EE shows the section of band.
FF shows the internal surface of band.
II the section of hub or boss and bearings of propeller.
Fig. 7 and 8, Sheets 1 and 2.
Shows the external edge view of propeller, also the ramp of band in the
proximity at the end of blades, giving the incline and decline surface of blades A
and B.
22 is the true circumference of propeller.
A A shows the incline surface of blades.

page_text: BB shows the decline surface of blades.
DD shows the edge view of obtuse angle flookes on either side of circumference
line. On one side of circumference line the obtuse angle flookes D D is connecting
the band EE to the angles of blades A. A giving an uniform surface from face of
band EE over the obtuse angle flookes D D and over the face of the incline of
blades A A.
On the other side of circumference line the obtuse angle flookes D D is connecting
the band EE to the angles of blades B B giving an uniform surface from face
of band EE over the obtuse angle flookes D D meeting the face of the decline of
blades B B.
E E shows the external surface of band, the centre of band retains the
circumference of propeller in the proximity at the end of blades, on each side of
the circumference line the edges of band are so shaped that they may receive
and deliver the waters freely and easily, the edges of band are deviating from a
true curve.
The surface of band E E is connected to the surface of obtuse angle flookes D D
meeting the surface of the incline and decline of blades A A and B B.
Therefore the surface of band, on either side of circumference line 2 2 continues
an uniform surface over the face of obtuse angle flookes D D and the face of incline
and decline of blades A. A and. B B.
FF shows the internal surface of band. The edges of band on each face of
propeller and in each semicircle, are eccentric curves springing from the edge of
one blade terminating in the circumference at the end of opposite blade, this
internal surface of band from one eccentric curve to the other eccentric curve are
cutting straight across the surface of band at oblique angles corresponding with
the pitch of blades and band.
II shows the hub and bearings of propeller.
33 shows the sectional pitch of blades, corresponding with Fig. 1 and Sheets 1
and 2, the pitch is set in at radius from centre of propeller, the remaining
radius to the circumference of "propeller has a variety of pitches.
Dated this 17th day of July 1890.
WILLIAM HOLLIS.
COMPLETE SPECIFICATION.
Improvements in Screw Propellers.
I, WILLIAM HOLLIS Esperance Villa Bullar's Road Bitterne Park near
Southampton late Mechanist in H.M. Service do hereby declare the nature of this
.invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to improvements in screw propellers, to be used by steam
vessels or ships of any tonnage, as single or twin propellers.
This invention has for its object the production of a propeller that shall be more
effectual in its operations, by concentrating its propelling friction on its posterior
surface, either when the ship is steaming ahead, or backing astern, than are those
heretofore employed.
This screw propeller is of geometrical outline having two or more blades, each
blade is attached to a band on its circumference, the other end of the same blades
is connected to a boss in the centre of propeller, the blades being at equal distance
from each other, the edge of each blade springs from the boss, and terminates in
the circumference line of the band, each angle of 'the blade is connected to the
band by flukes; the external surface of the band is connected to the decline angle
of the blade by an obtuse angle fluke, and the incline angle of the blade is connected
to the internal surface of the band by an acute angle fluke; the spaces between-
the blades, and within the boss and internal edge of band are apertures; the

page_text: 1 refers to the diameter me or propener.
2 refers to the line cutting at right angles from the centre of diameter
line in the clevation, and, in the edge view of propellers, it is the true
circumference.
3 refers to dotted line radius, or segment, across the face of blades in the
elevation, and also refers to transverse section of incline, and decline surfaces of
blades.
On the drawings the same reference letters wherever repeated, indicate similar
or like parts.
The word anterior surface, has reference to the face of propeller which divide
the waters either when the ship is steaming ahead, or backing astern; the word
posterior surface has reference to the face of propeller which deliver the waters
either when the ship is steaming ahead or backing asteru.
Figures 1, 2 and 3-Sheets 1 2 and 3-are elevations of single and twin screw
propellers, having a boss in their centres, and a band on their circumferences,
within the area of their bands, are two, or more blades, one end of each blade is
connected to the boss, the other ends of the same blades are connected by their
angles from the semiwidth of each blade to the external, and internal surfaces of
each band in relation to their incline and decline surfaces of each blade situated
on either side of the circumference line of propellers.
a shews the boss situated in the centre of each propeller.
shews the anterior face of blades, one end of each blade is connected to the
boss a-the other end of blades in their semi width form two angles. The angles
on the anterior edge of blades, form the obtuse angle fluke d-connecting the
blade b-to the external face of band e,- -the angle from the posterior edge
of blade b,-connects the internal surface of band f, to the surface of blade b,-
by the acute angle fluke c. The foregoing arrangements, shew, the connections
of boss to blade, also the angles from the semi width of blades, which connects
-

page_text: the blade either to the external or internal surface of band, each blade in like
manner is connected to the boss and band, thus forming the apertures g within the
area of propellers, and on either face of propellers.
c-represents the acute angle flukes on the anterior face of propellers-these
flukes are formed on the posterior edges, and in the semi width of blades b,-the
posterior angle of blade b, connects the surface of blade, to the internal surface of
band in each division within the area of aperture g. The fluke c-is the retiring
fluke on either face of propellers.
d-represents the obtuse angle flukes on the anterior face of propellers, the fluke
is formed on the anterior edge, and semi width of blade b,-the anterior angle of
blade, connects the surface of blade to the external surface of band e-this edge
of band is the formation of each aperture within the area of propellers.
The fluke d is the prominent fluke on either face of propeller.
c and d. The acute and obtuse angle flukes are attached to either surface, and
on either edge, from the semi width of blade b, connecting each surface of blade b-
and the surface of angles of the same blade to their respective surfaces of band e
and forming the external, and internal surfaces of band, either on the anterior
or posterior face of propellers; the surface of each and the several blades, are in
like manner so connected to the anterior and posterior surfaces of band in each
division of apertures g, within the area of, and on the face of propellers.
e--shews the external surface of band, connecting the surfaces of blades b-on
either face of propellers; the external curve of band of propeller is a true circle,
the blades are connected to the circumference by an eccentric curve. The area on
the anterior face of propellers shewing its divisions of apertures the eccentric
curve springs from the line of circumference 2, 2, meeting the angle of the blade
in the fluke curve d-, connecting the curve edge of blade b. The eccentric curve
on the posterior face of the aforesaid blade springs from the angle of blade b-in
the fluke curve -terminating on the circumference line 2, 2. The foregoing
arrangement gives the formation of the anterior, and posterior divisions of one
aperture; each, and the several apertures within the area of the anterior, and
posterior face of propellers, are arranged in like manner, as hereinbefore
described.
f-shews the internal surface of band; the line of edge forming the internal
surface of band -on the anterior face of propellers within each division of
apertures g, are eccentric curves springing from the line of circumference 22
connecting the angle of blade , at the fluke curve d, and making a continuous
curve from the circumference line to the boss, the posterior eccentric curve springs
from the angle of blade in fluke c,-and terminates in the circumference line 2, 2
of the adjoining blade, forming a continuous curve from boss to circumference
line.
g-are the apertures, the divisions on the anterior face of propellers are formed
by the eccentric curves, these curves spring from the circumference line 2, 2,
intersecting the angle of blade b, at the fluke curve d, making a continuous curve
from circumference to boss; the divisions on the posterior face, spring from the
angles of the aforesaid blade.b, in the fluke curve c-making a continuous curve
from boss to circumference.
Figures 4 and 5-Sheets 1 and 2-and Figure 10, Sheet .3 are sections of
propellers, cut through the diameter line 1, 1-as .described by letters in the
elevations, Figures 1 2 & 3, Sheets 1 2 and 3.
Figures 6 and 7 Sheets 1 and 2, shew the line cutting at right angles from the
centre of diameter line 1, 1, either end of the line terminating in the circumference
of propellers 2, 2,-the letters corresponding with those in the elevations Figures 1
and 2 Sheets 1 and 2.
Figures 8 and 9 Sheets 1 and 2, and Figure 11 Sheet 3.shew the external edge
view of single, and twin propellers, and the rampt edges of band e, on either side of
the circumference line 2, 2, in the proximity and on the end of blades b. 2, 2 is

page_text: the centre line of band e, this line retains the true circumference of the propellers.
3, 3, shews the transverse sectional pitch of blades the sectional pitch of the
incline and decline plane of blades -on the edge view of propeller, corresponds
with the range of blades b-shewn in the elevation of propellers Figures 1, 2 and 11
Sheets 12 and 3; the dotted lines across the face of blades from 3 to 3, are set
off at radius from the centre of propellers, on either face on the edge view of
propellers the dotted lines 3 3 correspond with the dotted lines across the face of
blades b, in the elevation of propellers; Figures 8, 9 and 11, Sheets 1 2 and 3 shew
the incline and decline plane of blades b; as shewn from 3 to 3 on either face of
propellers; and, on either side of the circumference line 2, 2 is the sectional pitch
of blades b, from the radius as shown in the elevations; the remaining division
of radius both in the elevations and edge view of propellers, spring from the
sectional incline and decline plane of blades, with the pitch of blades b, and
band e, combined, either plane of blades 6, in their semi width are so connected to
the radial surface of band e.-and internally and externally that within the limit
of this division of radius there are a variety and combination of pitches.
the blades in the edge view of propellers as shewn by dotted lines from 3 to 3
on either surface of propellers, these lines give the incline and decline planes of
the same blades b, on the division of radius as shewn in the elevation, the angles
in the semi width of these blades b, are connected to the internal surface of band e,
by the obtuse angle flukes d-these flukes are situated on either side of the circum-
ference line 2, 2, and connect either surface of the blades b,-to their relative
surfaces of band e-so that each surface of the same blades b, and the surface of the
obtuse angle fluke-d, intersects with the external surface of band e-on either side
of the circumference line 2, 2., d shews the edge view of the obtuse angle flukes d―
connecting either angle from the semi width of blade b, to the external surface of
band e-on either face of propellers each semi width of blades b, with the surfaces
of flukes d intersect the incline, and decline plane of blades b, and their surfaces
are connected to the external surface of band e. The letters on the sectional
drawings correspond with the letters shewn in clevations on Figures 1, 2 and 3
Sheets 12 and 3.
Figure 12 Sheet 3, is the edge view of propeller, or the counter view of Figure 11
Sheet 3 giving the view of the rampt edge of band on either side of the circumference
line 2, 2; the edge of band is rampt out, the curve springs from the proximity,
and on the end of blades, intersecting with their relative edges of band in the
centre of apertures, and each and the several divisions of apertures g-of band e,
are in like manner rampt out. The letters on the sectional drawings correspond
with the letters shewn in the elevation Figure 3 Sheet 3.
As it is evident that the variety of pitches of blades, and the variety of pitches
of band, and the variety of twist and ramp of band connecting each and every
blade with each other, can be altered from the views already shewn so as to obtain
the greatest possible speed, without departing from the spirit or principle of this
invention, it is to be clearly understood, that, I do not confine myself to any
particular pitch, or pitches of blades, or to any particular pitch or pitches of band,
or to any particular twist or ramp of band, or any sizes of propeller.
Having now particularly described, and ascertained the nature of my inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is,
1-A twisted, ramped, graduated, and propulsive band on the circumference of
any propeller, of two, or more blades, and so connected to each and every blade, as
to be a continuation of each blade, one to the other, and containing a number and
variety of necessary pitches.
2-A propeller with a twisted, ramped, and graduated, and propulsive band on
its circumference as above described, that will divide the waters on the anterior
face, and gather, and deliver the same waters on the posterior face, in solid,
concentrated, and propulsive volumes.

page_text: 3The general construction of a twisted, ramped, graduated, and propulsive band
' on the circumference of a propeller.
Dated this 31st day of March 1891.
WILLIAM HOLLIS,
Esperance Villa, Bullar's Road, Bitterne Park, near Southampton.