IMPROVEMENTS IN PROPELLING APPARATUS FOR STEAM SHIPS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I, BOBERT WILCOX of Fawkner Street St Kilda in the Colony of Victoria
Engineer do hereby declare the nature of my Invention for "IMPROVEMENTS
IN PROPELLING APPARATUS FOR STEAM SHIPS" and in what manner the same
is to be performed to be particularly described and ascertained in and by the
following statement:—
My improved propeller for steam ships has been designed for the purpose of
superseding the screw propellers at present in use which are placed at the stern
of the ship, and is intended to be called the "Oscillating Propeller."
My propeller is placed under the bottom of the ship, so that it is always under
water and consequently cannot “ race "which is one of the greatest objections to
ordinary screw propellers.
My improved propeller consists of two oar-shaped blades whose shafts are
properly fitted and work in the bearings provided in the lower end of a vertical
cylindrical trunk, which also works in suitable water-tight bearings and projects
through the bottom of the ship in a gap provided in the keel of the vessel for that
purpose. To this trunk and consequently to the blades a reciprocating motion is
given by an arm on it, which is worked by a connecting rod from the crank shaft
of an engine whose stroke is so regulated as to give to said blades a travel of one
hundred and nine degrees or there abouts. The reciprocating motion may be
imparted to the trunk through any arrangement of machinery, and by any
description of engine. A feathering motion, or motion whereby the blades are
alternately turned on their edge at one end, and on their side at the other end of
the stroke is given to said blades, so that when they are working in the same
direction as the ship, the edge of same offers as little resistance as possible to the
water, as hereinafter more fully explained. Reversing gear is also provided, by
means of which the blade feathering mechanism may be so set as to immediately
alter the blades from propelling the vessel ahead, to propelling her astern, or one
of the blades may be caused to work ahead, and the other astern, so as to turn
said vessel. These movements can be accomplished while said trunk and attached
mechanism, and blades are in full work, and without stopping or reversing the
enginc.
Referring to my Drawings (on Sheet 1) Figure 1 shews a longitudinal view of
a vessel having a pair of my propellers fitted thereto at their proposed positions,
and Figure 2 cross section on the line a a looking forward. Figure 3 cross section
on the line b b also looking forward shewing the blades in their normal working

page_text: positions. Figure 4 (Sheet 2) is an athwart ship, and Figure 5 a fore and aft
elevation of my improved propeller, and of the machinery for driving it. Figure 6
is an athwart ship sectional elevation of same. Figure 7 is a plan of lower part
of same shewing connection from crank shaft of steam engine to trunk, and
Figure 8 is a plan on top of suspension plate. Figure 9 is a vertical fore and aft
section of the trunk. Figures 10 and 11 are top and bottom plans of same.
Figure 12 is a horizontal section at c c in Figure 7, and Figure 13 plan of bottom
of said trunk with lower cap removed. Figures 12° and 10 are similar views to
Figures 12 and 10 of an alternative method of arranging the feathering cranks.
Figures 9 and 13ª shew vertical section and plan of an alternative construction
of the bearings for the propeller shafts. Figure 14 is a back view of the roller
carriage. Figure 15 is a plan of top, and Figure 16 a plan of bottom roller paths.
Figure 17 horizontal section at d d Figure 4. Figures 18 and 19 are plans of the
upper and lower striking gear for operating the paths, and Figures 18 and 19" shew
an alternative construction of the striking arms by facing them with vulcanite
or some such material marked R. Figure 20 shews an alternative form of blade
for the propellers. Figures 21 and 21ª shew alternative constructions of the
feathering rods, and Figure 22 shews half elevation, and half section, and Figure 23
half top plan, and half horizontal section of an alternative arrangement for
transmitting the feathering motion to the before mentioned propeller blades.
I will refer now to all the Figures excepting those shewing alternative methods,
similar letters will indicate the same parts throughout the Drawings.
A and A¹ are the two blades each on its own stem or shaft A' and forming
together one propeller. On these shafts are formed the solid collar A³, discs A³,
and crank pins A³ as shewn. B is the trunk, and B' the vertical shaft to which
it is attached by flanges B', bolted together by the tap bolts B. The lower end
of the trunk B is enlarged in diameter, and has a cap B* fitted thereon. This cap
is let into a suitable recess in the trunk, and bolted thereto by means of the tap
bolts B. This cap and the lower end of the trunk form the bearings for the
shafts A2, and discs A, and a packing gland B is also fitted into them as shewn.
In said trunk B, a hole is provided at b, so as to form an outlet for any sea water
which may get there. C is the bed plate to which the standards C₁ are bolted,
said standards supporting the circular frane D of the roller paths. Into the top
flange of said frame D is fixed the four columns E which support and are bolted
to the suspension plate E', which has a central boss E2 on its upper face to form
a bearing for the vertical shaft B', and also to form a path on which the suspension
rollers E travel. These rollers revolve on the transverse shaft E4, which is
fitted into the uppermost end of said vertical shaft B¹. E is a loose collar
fitted on the shaft B and working against the underside of suspension plate E'
as shewn. A large boss C2 is formed on, and projects downwards from the bed
plate C. Into this boss is fitted a brush C which is lined inside with strips of
lignum vitae C as shewn in Figure 17: Above this is a stuffing box C³, fitted
with gland C. These parts C³, C and C are made in halves, C³ being bolted to
the bed plate by the bolts C, while the gland into stuffing box is fastened by the
bolts C. B' are the connecting rods. B³ the cranks working in the bearings B
which are fitted into the upper square portion of trunk B. F are the roller
carriage brackets carrying the path rollers F, friction rollers F³, and guide rods F³,
which work in the guide brackets F fitted on the outside of trunk B,
carriage has an oblong hole or slot Fs formed in its back face in which the outer
pins or cranks BS work. D¹ are the upper, and D the lower movable roller paths,
the upper ones baving a dovetailed slide piece D³ formed on them which slides in
a suitable recess formed in the path or Hange of frame D, and the lower ones
having the two dovetailed slide pieces D' which work in suitable recesses in
lower roller face of the frame D. It will be noticed that the working surface of
the lower roller paths D are bevelled to suit the lower rollers F as shewn,
These movable paths D1 and D2 have snugs D formed on their outer periphery
between which the pins D are fitted. G G are brackets fixed to the frame D, by
This

page_text: means of the bolts G¹, and have a pin G fitted into them, which supports the
lever G³. G is a rod connecting said lever G³ with bell crank G³. This bell
crank has a slotted hole Go for regulating the stroke, and is supported in the
bracket G, which is bolted to the top of the circular frame D. Gs is a rod
connecting the arm G on the square portion of the tappet shaft H to said bell
crank G. G10 is a forked bracket bolted to the suspension plate for supporting
the arm G. H' is a cranked lever supported in the bracket H2 bolted to the top
of suspension plate E¹. This lever has a bow or forked end which carries two
pins H³ fitted therein, said pins being placed in the groove formed in the circular
disc H, which is keyed to the top end of the tappet shaft H. This tappet shaft
is supported at top in a bearing in the suspension plate, and at bottom in a
bearing in the arm H³ projecting from before mentioned bracket G7.
and H are the tappet arms projecting from said tappet shaft H. I is the upper
collar of the form shown in Figure 18 having the three striking pins. I bolted into
the three oblong holes provided therein. It is keyed on to the vertical shaft B¹ as
shewn. J is the lower collar of the form shewn in Figure 19 and having the three
striking pins J¹ bolted in the oblong holes therein, which said holes are for the
purpose of adjustment, and which said collar is also keyed on to the vertical
shaft B¹. The pins 1¹ and J¹ in the brackets I and J may have set screws as
shewn at J fitted into the lugs so as to prevent said pins from moving sideways.
He, H
K is the cylinder of the engine, K¹ its piston rod, K³ crosshead K³ connecting
rod, K crank shaft supported in bearings K' at top, and footstep KⓇ at bottom,
which has a wearing piece of lignum vitae K' fitted therein. K is the fly wheel.
This engine gives the necessary motion to the connecting rod L which is connected
at the one end to the crank shaft K', and at the other to the pin L', between the
arms L³, formed on the vertical trunk B, thereby giving the required reciprocating
motion through said trunk to the propeller.
The alternative arrangement of one of the double ended cranks B³, so as to
cause the after edges of the blades to always lift up in the feathering motion
when going aft, and which I think is preferable is accomplished by simply making
one of the cranks with the pins on different sides of its centre, which crank is
marked B¹ in Figure 12 of the Drawings. Figure 10° shews top view of trunk B,
with the guide brackets F altered to suit this construction.
Figures 9 and 13ª shew the alternative construction of the bearings for the
propeller shaft in which the half brasses M. are set into the bottom of the trunk
and cap, and held therein by the set screws M. Metallic and india rubber
packing rings M2 and M³ are inserted in the stuffing box as shewn.
Figure 21 shews the alternative construction of the feathering rods so as to be
able to adjust the top and bottom brasses N, by the nuts N' on the ends of the
strap N2, which strap passes around the rod N³ and the lower brasses, or the
end of the strap may be formed into a bow having a central set bolt N' as shewn
in Figure 21 of the Drawings.
Figures 22 and 23 shew an alternative arrangement for conveying the motion
from the roller paths to the feathering rods in the trunk B. By this arrange-
ment the cranks BS in Figure 12 and the carriage F in Figure 14 are dispensed
with and the path rollers work on bearings projecting from the guide block O
which has friction rollers O' fitted to it working against the inner side of the
guide box 0%, on the one side, and against the flat face of the trunk B on the other
side. Projecting inwards from said guide block O, and through the slot in said
trunk is a pin 0³ to which the connecting rod B' is attached. From thence to
the blades the mechanical arrangements are the same as already described and
shewn more especially in Figures 6 and 9.
In each steain ship there may be two or more of my propellers, and two or more
sets of the requisite driving machinery. In Figures 1, 2 and 3 I have shewn two
of such sets, which is what I prefer.
The operation of my propellers and the machinery for driving and governing
same in a ship fitted as I prefer with a pair of such propellers and their driving

page_text: gear as illustrated in Figures 1, 2 and 3 is as follows. Motion being imparted to
the trunks, and from them to the propellers by the contrivances shewn and already
described causes the starboard blade on the forward, and the port blade on the after
propeller to be vertical when travelling aft, and consequently the ship to be thereby
propelled forward, and the port blade on the forward propeller, and the starboard
blade on the after propeller to be in the reverse position, that is edgewise against
the water while travelling forward, or in other words, one of the blades of each
propeller should be vertical for that portion of the astern stroke during which it is
designed to be so, and edgewise for its full forward stroke as shewn at A¹ and A in
Figure 4. At each end of the stroke and in this case as the lower tappets H³ are
in position, and supposing the machine to have just returned from the forward end
on the port side, then the lower striking frame J, which is keyed on to the upright
shaft extension B of the trunk B would have come into contact with the arm
tappet H³, on the tappet shaft H, and through the medium of the arms G³, con-
necting rod 8, bell crank G³, connecting rod G', and lever G³, which operates the
top and bottom movable paths D and D' will place them in the position shewn in
Figure 4. The dotted circles in Figure 19 indicating the position the pins J¹
assumed at such time, so as to so place the movable paths. When the end of this
stroke is reached and while the path rollers F' are clear of the movable paths D¹
and D, the striking pins J¹ will come in contact with the opposite side of the tappet
arms H8, thereby shifting the movable paths to the reverse positions, the top one D'
on the port side will be out, and the lower one D2 in, and on the starboard side
the top one D¹ will be in, and the lower one D2 out, so that the carriages F, and
rollers F travelling between the paths as described will cause the blade A, to be
vertical in coming astern, and the blade A¹ edgewise in going ahead. The feathering
gear from path rollers F¹, to blades A and A¹ is as follows. The rollers F¹ being
attached to the carriages F, and such carriages having slots F³ at their back faces
into which the outer pins of the double cranks B³ work, and the connecting rods B7
inside the trunk B being connected at their top end to the inner pins of the
cranks B and at their lower ends to the pins A5 on the discs A', the carriages F
are caused to rise and fall by travelling on the paths, and so cause the blades A
and A¹ to twist or feather from the vertical to the horizontal position.
When it is required to reverse the course of the ship from ahead to astern which
in practice means, that the carriage F should travel on top of the movable roller
paths D' when working forward and consequently the blades be vertical when
going forward. I require to place the cranked hand levers H' in the position
shewn in Figure 6, and so raise the lower arm tappets H³ clear of the lower
striking frame J and the same movement brings the upper arın tappets H and H
into the line of contact with the upper striking frame I, which, when said frame
aud tappets come in contact reverses the movable paths as required.
Having thus described the nature of my Invention, and the manner of perforining
same I would have it understood that I do not confine myself to the particular
shapes or forms of the propeller blades shewn in the Drawings, as any convenient
form of blade having the required surface to propel the ship may be used, and
further I do not confine myself to any particular form of steam engine for driving
my propeller, as any description will do if of sufficient power and placed in any
convenient position adjacent to the trunk of said propellers, but what I believe to
be new and therefore claim as my improvements in steam ship propellers and in
the machinery for driving same is :-
:-
First. Constructing steam ship propellers with two oar shaped blades so arranged
and connected as that each blade has a horizontal reciprocating and a feathering
motion substantially as herein described and as illustrated in the accompanying
Drawing.
Second. The combination with my said propellers of a hollow trunk to receive
the rods which give the feathering motion to the propeller substantially as herein
described or explained.

page_text: Third. The combination of parts forming my improved machinery for commu-
nicating and translating the motion of the piston rod of the engine into the
necessary motions for working my said propeller substantially as herein described
and explained.
Dated this Fifteenth day of May One thousand eight hundred and eighty-four.