Improvements in and relating to Screw Propellers for Steam Ships.
Year: 1892

page_text: Date of Application, 20th Sept., 1892-Accepted, 22nd Oct., 1892
COMPLETE SPECIFICATION.
Improvements in and relating to Screw Propellers for Steam Ships.
I, DAVID URCH of No. 22 New Castle Ave., Portsmouth, in the County of
Rockingham, State of New Hampshire, United States of America, Gentleman, 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:-
My invention relates to means adapted for use, either principal or auxiliary, for
propelling and controlling marine craft; and it consists in certain constructions,
combinations and arrangements of a screw propeller, and mechanism for operating
and manipulating it, whereby many useful advantages are secured, among which
are, the conveyance of the driving power from the shaft to a propeller having its
support at right angles or nearly so to said power transmitting shaft; the capability
of swinging the propeller into and out of the water concentrically with said power
transmitting shaft, and of working the propeller at any proper angle less than a
right angle to the horizon; the capability of detaching the propeller and storing
it away when it is not required as an auxiliary relief propelling means, and of
again replacing it when its use is required for aiding disabled vessels, or for any
use that it is adapted for in connection with marine craft; the relief of the driving
shaft from weight of the propeller proper and its mechanism; the reduction of
friction at the point where the propeller is directly supported; the utilization of
the propeller hub or sleeve as a chain pulley, and as an adjunct to the propeller
blades for aiding in propelling the craft to which the invention is applied; and
the adaptation of the screw propeller to either the sides or centre of craft of
various kinds having a centre keel or centre board; and to such as row boats, and
craft that come under the head of catamarans, operated by manual or other power,
as will be hereinafter described.
In the accompanying drawings,
Figure 1 is a side elevation showing a screw propeller with my improved hub or
sleeve, propeller support, suspending, driving, and manipulating or lowering and
raising mechanism.
Figure 2 is a partial section at a right angle to the view shown by Figure 1,
and an end elevation of the parts not shown in section, the driving chain being
removed.
Figure 3 is a flat or face view, and Figure 4 an edge view of a different form of
driving chain from that shown in Figure 1.
Figure 5 is a broken detail view, showing a slight change in the supporting
bearings, and illustrating one way of attaching the invention to the side of a
craft.
Figure 6 is a vertical section and partial elevation of the parts shown in
Figure 5, and at a right angle to said view.
Figure 7 is an edge view of the chain formed of links such as are shown in
Figures 3 and 4, as it appears before the necessary half twist is given to it.
Figure 9 is a top view of a treadle operated catamaran (the rider's seat being
shown by dotted lines) having my improved propeller mechanism applied to it.
Figure 10 is a side view of the parts shown in Figure 9, the propeller proper
being lowered for use.
Figure 11 is a side view of the parts shown in Figure 10, the propeller proper
being raised out of the water.
Figure 12 illustrates my invention applied in a hollow centre box of a pleasure
or row boat.
Figures 13 and 14, show my invention applied to the sides of different styles of

page_text: marine craft.
In Figure 13, the propelling mechanism is shown raised out of the
water, and in Figure 14 lowered into the water.
Figure 15 is a cross section showing the invention as applied on craft similar to
those shown in Figures 13 and 14.
A in the drawings represents a driving shaft mounted in bearings a. B a power
transmitting chain pulley, keyed on said shaft; C plates arranged close to said
pulley and hung upon lateral extension bearing portions a¹ of the bearings a, so as
not to ride upon the said shaft; 1) an auxiliary chain-supporting, directing and
tension pulley, applied between the plates C on an idler shaft c, being fitted in
vertically adjustable bearing blocks d, the blocks being adjusted by screws, d', in
order to regulate the tension upon the chain; E is a bifurcated suspending plate,
its branches being constructed and arranged so as to diverge in opposite directions
from the central portion of the plate. This suspender is bolted at f to the plates C,
and at its lower ends is formed with cylindrical boxes g, into which the ends of a
stationary shaft F, which serves as a propeller support, are inserted; and said
shaft is secured against turning by set screws h having, preferably, diamond shaped
heads; G is a screw propeller having, preferably, two blades ii. The hub of these
blades is in the form of a long sleeve with an intermediate enlarged portion m
having a groove m¹ formed therein. This enlarged portion comprises two oppositely
tapered conical portions connected at their bases by a concave annual portion of
less diameter than the base of the cone portions; and on each of these conical
portions, spiral ribs n, tapering to nothing in opposite directions, are provided, as
shown. By this construction, a means answering the purpose of a grooved pulley
for a driving chain H, is provided, and at the same time a hub or sleeve is secured
which is light and symmetrical, and by its spiral ribs acts as an auxiliary to the
propeller in moving the craft. The hub or sleeve being long and fitted loosely on
the stationary shaft, gives great steadiness to the propeller; and all torsional
strain, and the great friction experienced when the shaft, as well as the propeller
revolve, are overcome. The chain His arranged by reason of the pulley D
so as to pass properly upon the hub of the propeller although the same is placed
at right angles to the driving pulley shaft A. The chain shown in Figure 1
contains an even number of links, and is constructed with a half twist or turn in
its entire length, as illustrated in Figure 8. Unless an even number of links are
used in a chain of the type shown in Figure 1, and a half twist or turn, either to
the right or left, is imparted to the chain, it is found that this part of the invention
is of very little practical utility. Therefore I employ an even number of links in
the chain shown in Figure 1, and before converting the chain into an endless one,
I give it a half twist or turn to the right when I desire to transmit power to run
a shaft in one direction; and I give it a half turn or twist to the left when the
purpose is to run in an opposite direction. I is an adjusting and lifting bar_con-
nected to the suspender E. By this bar the whole structure can be swung down
or up on the extension of the shaft bearings, concentrically with the driving shaft,
and when adjusted either for operation or disuse it can be secured firmly by a pin
at p or by a chain p¹.
When the structure is lowered so that the shaft of the propeller is parallel with
the water, or its suspender is at a right angle to the horizon or vertical, it will
remain so, while the power is applied, both whether the propeller is revolved back-
ward or forward, and it will not change its position even if the pin at p is not
brought into use for holding it; and while this is so; if the power is stopped, the
swinging suspender with propeller can be moved in the arc of a circle by a slight
force of the hand. This proves that, while the lifting and adjusting bar is a useful
device for manipulating the suspender and attached propeller, its use for holding
down the propeller to its work, while the power is applied, is not necessary to the
successful working of the propeller, therefore I do not limit myself to its use as a
holding down means when the suspender stands at right angles to the horizon, or
vertical, and yet I regard it as an important adjunct as an adjusting and
manipulating means.

page_text: A chain may be used for raising and lowering the propeller in lieu of the bar.
The adjustment for use may be to a position less than a right angle, by having a
series of holes in the lifting bar. So also may the adjustment out of use be to a
position less than a right angle, by having a series of pins for the hook of the chain
to catch upon. In cases where the invention is applied to the sides of a craft,
overhanging plates J, forming housings, may be provided as represented in
Figures 5, 6, 13, 14 and 15. And when the invention is applied to the row or
pleasure boat, a central box may be constructed in the boat and the propeller rise
and descend therein the same as in centre board boats. It might also, in this
manner, be applied usefully to steam boats. In applying it to catamarans, it is
mounted upon two longitudinal pieces q, connected to transverse pieces, and
arranged to swing on a power shaft having crank arms with treadles q', as illus
trated in Figures 9, 10 and 11. The power pulley B, as well as the directing
pulley D, is grooved, and in the grooved periphery of the pulley B, projecting
sprocket teeth are provided so as to take hold of the chain and give it a positive
movement, and similar teeth for the same purpose are provided in the grooved hub
of the propeller proper. In Figures 3, 4, 7 and 81 have shown flat links k for
forming the chain, which may be adopted if desired, and when adopted it is not
necessary to have an even number.
To still further avoid friction, the suspended plates C might have anti-friction
rollers at their points of bearing; so also might the driving shaft be provided
with such rollers at its point of bearing in the boxes.
When my invention is applied as shown in Figure 13, the major portion is
forward
enclosed, and the driving wheel shaft passes out at right angles to the upper
corner of the box, and rests in substantial portions, and the propeller is raised and
lowered by the lifting bar, I, which projects through the top of the box, in
about the same manner as the rod of the common centre board is now used. A
With
chain may be used in raising and lowering the propeller in lieu of the bar.
this arrangement, either treadles for foot power or cranks for hand power or
steam, electricity or any other suitable means, may be adopted for driving
the shaft.
My invention will transmit power to either horizontal, or perpendicular shafts;
or to shaftings at any inclined angle; but its most effective use is at a right
angle to the driving shaft; and it is capable of use at high speeds as well as
low speeds.
The invention may be used either as a principal or an auxiliary means of marine
propulsion for almost every class of vessel or boat known; and being compact and
simple and yet powerful, it can be efficaciously employed. Its attachment to the
sides of any craft at points nearest any available power on board, can be effected
in an hour or two, as it requires no alteration to the vessel, further than the
insertion into the planking of a strong bearing for the power shaft, and the fastening
to the boat of the plate J, as a bearing for the outer end of the power shaft; and
the said parts can be readily removed and stored away if not further required, but
if not removed, the propeller can be quickly swung up out of the way, and as easily
dropped to its operating position again when needed for use, and, when adjusted for
use, or out of use, can be, if desired, firmly fastened by suitable means as herein-
before described. The provision for raising and lowering the propeller without
disarrangement of any of its parts, or endangering its operative character, is very
important; and the fact that the mechanism runs equally well whether the
propeller shaft is placed at a right angle to the horizon or parallel therewith,
establishes the great utility of the arrangement. The wheels, in this arrangement,
may be so placed as to have the transmission of power in one way direct, and as a
chain, unlike a belt-can be run loosely, the slightly indirect return of the loose
side of the chain is effected with hardly noticeable friction. When in motion, there
are two movements of the chain, one over the wheels and the other a half revolution
of itself or a turn inside out, every time it passes once around. If the chain of the
clevis form shown in Figure 3, 4, 7 and 8 is used, the grooves in the rim of the

page_text: drive wheel and pulley will be of a form to receive the chain edgewise, but
the number of links may be even or odd. Such a chain would produce less
impediment to the progress of that portion of it necessarily submerged, though, in
this device both the chain and shaft supports do not offer half the obstruction
experienced from the use of the rudder post now in use, and it is the design of my
invention to avoid impediment through the water without sacrificing power. By
raising the pulley D, the very nicest degree of tension on the chain can be effected
and retained by tightening the set screws. By providing the thin spiral projections
on the hub or sleeve, that part which would be an obstruction in the revolution of
the propeller is made a most efficient aid in that direction, and at the same time
these projections serve the purpose of the flange in the ordinary wheel, and
effectually prevent the chain from coming off, and they also act as guides to convey
the chain to its exact place upon the wheel.
My invention as an auxiliary means of propulsion of sailing vessels carrying
hoisting engines will prove valuable, as it occupies only the bare width of a twisted
propeller blade, and when swung up out of the water is neither in the way, or any
impediment to the motion of the vessel. The organization is such that the power
pulleys may be enlarged so as to use small propellers in waters of slight depth.
In rivers and harbours, vessels provided with my invention can be moved without
delay without the aid of a tug boat, and when becalmed at sea they may still make
progress with this device driven by the hoisting engine; and with two of these com-
paratively inexpensive propellers on the sides of a vessel, each driven independently,
a vessel may be steered or turned around without moving forward or backward,
and may be handled and berthed more easily, and with finer and truer precision,
than by the use of any other means hitherto employed. For steamers of every
class, provided with auxiliary engines, my invention may be used to increase their
speed and, particularly in cases of ocean and large craft, by utilizing their small
engines to operate it.
For naval vessels, "freighters" and "luggers," and every kind of craft having
any spare power, this invention will be found very useful as an auxiliary in moving
or controlling their position. For small row boats, this device can be used, and
the operator can face his direction instead of, as with oars, working backward; and
while the oarsman must exert his power when his hands are farthest from the line
of the body, the operator of this device can exert power more easily and with
greater force, because he can apply power from a point close to the body.
And as
an attachment to the catamaran style of craft, it is found very useful, and avoids
the necessity of making such structures of great length.
My invention overcomes many of the experienced difficulties arising from the
drag of the propeller on vessels under sail and lessens the difficulty and labour
required to raise and lower the propeller, and overcomes the objection to the
unsymmetrical appearance of vessels equipped with such contrivances, and admits
of the raising and lowering being performed under almost any conditions of sea and
weather.
Having now particularly described and 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. A propeller for marine craft, driven by a chain arranged about pulleys, and
operated by a driving shaft, the support or shaft of the propeller being arranged
at a right angle or nearly so to the driving shaft substantially as herein
described.
2. A propeller for marine craft, having a chain, whereby it is driven, constructed
with a half twist and applied upon a driving and controlling pulley, and operated
by the driving shaft arranged at a right angle to the propeller shaft or support,
substantially as herein described.
3. A suspending frame, swinging concentrically with the driving shaft, and
carrying the propeller, the said suspending frame maintaining its vertical position

page_text: when the power is applied, without the aid of fastening means, and being free to be
moved in the arc of a circle by a slight force when the power is cut off, substantially
as described.
4. The pulley D having its shaft arranged in adjustable bearings mounted on set
screws, in combination with the driving pulley B, the driving shaft, the chain and
the propeller hub, substantially as described.
5. The combination of the bearings of the shaft having lateral extensions, the
suspending plates fitted around said extensions, the suspender connected to the ends
of a stationary shaft, the driving shaft, the driving pulley, the directing pulley, the
chain, and the propeller hub arranged at right angles to the driving shaft,
substantially as described.
6. The combination of the suspending frame and the propeller having a sleeve or
hub, with a stationary shaft, substantially as described.
7. In a propeller for marine craft, the shaft bearings having lateral extensions,
in combination with the propeller, and the means by which said propeller is
suspended, and with the shaft and the means by which the propeller is revolved,
substantially as described.
8. The propeller hub formed with a groove for the chain, and with spiral ribs on
each side of said groove, in combination with the stationary shaft and a chain for
revolving the propeller, substantially as described.
9. The combination of a screw propeller, a suspending means hung concentrically
with the driving shaft, and adapted to swing around said shaft in a circle or a part
of a circle, and a lifting device, substantially as described.
10. In a propeller for marine craft, the combination with a boat, of a crank shaft,
a driving pulley on said shaft, a directing pulley, a suspending means, a propeller
having its shaft arranged at a right angle to the driving shaft, a chain passed
around said pulley and around the hub of the propeller, and a lifting device, the
said mechanism being supported by substantial portions of the boat, substantially
as described.
11. The combination of a boat provided with the inner and outer bearings, the
driving shaft, the plates C, the bifurcated suspender E, the supporting shaft for the
propeller, the propeller having revolving hub, the driving pulley, the directing
pulley, and the chain passed around the pulleys and the hub of the propeller,
substantially as described.
Dated this 20th day of September 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.