Improvements in or relating to the Propulsion and Steering of Navigable Vessels.
Year: 1894

page_text: Date of Application, 13th Nov., 1894
Complete Specification Left, 1st Aug., 1895-Accepted, 5th Oct., 1895
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Propulsion and Steering of
Navigable Vessels.
A communication from HERMANN DEMNITZ, Gentleman, of Niedersedlitz, near
Dresden, Saxony, in the Empire of Germany.
I, ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex,
Chartered Patent. Agent, do hereby declare the nature of this invention to be as
Follows :-
:-
This invention relates to the propulsion of ships and in particular of small craft
(boats etc.,) as a substitute for the ordinary oars. It operates with several devices
which the inventor designates as "thrust-blades," consisting of rods provided with
pivoted flaps which are moved to and fro in the longitudinal direction of the
vessel in such manner that, on the return-stroke, the entire surface of the flap is
opposed to the water through which it passes, whereas, on the forward stroke, it is
pushed through the water idly or without resistance.
The apparatus comprises two such sets of "thrust-blades." On each side of the
ship's hull is arranged a lever, to which are connected two rods with flaps as
above-named, in such manner that while the one rod is making a working-stroke
backwards, the other is making its forward or idle stroke. In whichever direction
the lever is moved, on one side of the hull or on the other, there is always one
such device in active work, on each side, so that the vessel progresses steadily
onwards without deviation from its course. With this arrangement it would be
possible to dispense with the steering gear and rudder, as by operating one of the
systems more than the other the boat or vessel may be caused to take any desired
course.
By the aid of this propelling apparatus the inventor hopes to obtain a much
greater useful effect in the propulsion of the craft than by the use of ordinary
oars, which moreover require skilful management; furthermore the person
operating it can turn his face forwards, in the direction of motion.
A lever on each side of the hull is pivoted on a projecting bolt, and has pivoted
to its two ends two rods terminating at their free ends in cross-bars or vertical bolts in
which the flaps are pivoted. The pivoting of the flaps on vertical bolts or pivots,
is more suitable and advantageous, than on horizontal bolts because with the latter
the weight of the flaps would prejudicially affect their action in the manner
hereinafter described.
Suitable steps or abutment surfaces on the cross-bars prevent the flaps from
swinging beyond the end positions.
Engaging with the upper arms of the levers are arranged the motor levers,
which can be operated by means of handles so as to be set in swinging motion
which, by means of slots in said motor-levers and pivot-bolts at the triple connection
connecting the two levers and the flap-rod at each side of the boat is transmitted,
so that the flap-rods are caused to reciprocate to and fro in a direction parallel with
the longitudinal axis of the boat. Eyes are secured to the hull to serve as guides
for the movement of the flap rods.
When the rods are thrust forward the flaps swing backwards until they form to
each other an acute angle with its apex directed forwards. At the end of this idle
stroke, when the motion is reversed, and the rods swing backwards, the pressure of

page_text: the water, acting against the rear-surfaces of the flaps, which, by reason of their
articulation or hinged joint, at once assume a position at right angles to the rods.
In this position a thrust is exerted against the water-pressure, while a propelling
impulse is imparted to the boat. At the next change in the direction of motion
of the rods, the flaps resume their previous angular position and as the rods move
forward are drawn edgewise through the water with little or no resistance. The
angular position of the flaps to each other is necessary to enable the water, in its
effort to thrust the flaps into the position at right angles to the rods, to have a
purchase ou their surfaces.
It is a matter of indifference whether the levers are simultaneously moved in the
same direction or in opposite directions, relatively to each other, inasmuch as on
cach side of the hull, in either case, there will always be one operative "thrust-
blade," the other making an idle stroke. On the other band the operation of one
lever only will change the direction of the boat, without the co-operating aid of
the steering-gear and rudder.
Although the inventor has designed this propelling device for use by hand-power,
there is nothing to prevent the employment of a motor in connection therewith.
In this case the motor may be applied either directly to the flap-rod lever, or to
a shaft on which said lever is secured, with the aid of any known kinematic
means. Should the driving means be of such kind that both the sets of operative
devices can only be worked together and not separately, steering mechanism must
obviously be provided.
Dated this 13th day of November 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.
Improvements in or relating to the Propulsion and Steering of
Navigable Vessels.
A communication from HERMANN DEMNITZ, Gentleman, of Niedersedlitz, near
Dresden, Saxony, in the Empire of Germany.
ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, 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 the propulsion of ships and in particular of small craft
(boats etc.,) as a substitute for the ordinary oars. It operates with several devices
which the inventor designates as "thrust-blades," consisting of rods provided with
pivoted flaps which are moved to and fro in the longitudinal direction of the vessel
in such manner that, on the return-stroke, the entire surface of the flap is opposed
to the water through which it passes, whereas on the forward stroke, it is pushed
through the water idly or with little or no resistance.
The apparatus comprises two such sets of "thrust blades." On each side of the
ship's hull is arranged a lever, to which are connected two rods with flaps as
above-named, in such manner that while the one rod is making a working-stroke
backwards, the other is making its forward or idle stroke. In whichever direction
the lever is moved, on one side of the hull or on the other, there is always one such
device in active work, on each side, so that the vessel progresses steadily onwards
without deviation from its course. With this arrangement it would be possible to
dispense with the steering gear and rudder, as by operating one of the systems
more than the other the boat or vessel may be caused to take any desired course.
By the aid of this propelling apparatus the inventor hopes to obtain a much

page_text: greater useru efect in the propulsion of the craft than by the use of ordinary oars,
which moreover require skilful management; furthermore the person operating it
can turn his face forwards, in the direction of motion.
In the accompanying drawings,
Fig. 1 is a side elevation of the craft showing one set of "thrust-blades";
Fig. 2 is a part plan showing the stern end of the boat;
Fig. 3 is a vertical cross section of the same;
Figs 4 and 5 illustrate a modification of the thrust blades, as seen from above,
Fig. 4 showing them in the working stroke and Fig. 5 in the idle or back-stroke,
and
Fig. 6 is a side elevation of Fig. 5.
A lever b on each side of the hull is pivoted on a projecting bolt a, and has
pivoted to its two ends the rods cand c' terminating at their free ends in cross-bars d
on vertical bolts e in which, the flaps are pivoted. The pivotting of the flaps /
on vertical bolts or pivots, is more suitable and advantageous, than on horizontal
bolts because, with the latter, the weight of the flaps would prejudicially affect
their action in the manner hereinafter described. Suitable stops or abutment
surfaces on the cross-bars d prevent the flaps f from swinging beyond the positions
indicated in Fig. 1.
Engaging with the upper arms of the levers b, are arranged the motor levers.
which can be oscillated by means of the handles h. This oscillating motion, by
means of a slot in each said lever g and pivot-bolt at the joint connecting the two
levers band g and rod c at the same side of the boat causes the rods c and c¹ to be
reciprocated to and fro in a direction parallel with the longitudinal axis of the boat.
Eyes are secured to the hull to serve as guides for the movement of the rods c c¹.
When the rods cor carriers cd, c'd are thrust forward the flaps swing
backwards until they form to each other an acute angle with its apex directed
forwards. At the end of this idle stroke, when the notion is reversed, and the
rods are moved backwards, the pressure of the water, acting against the rear-
curfaces of the flaps, which, by reason of their articulation or hinged joint, at once
assume a position as shown, at right angles to the rods. In this position a thrust is
exerted against the water, while a propelling impulse is imparted to the boat. At
the next change in the direction of motion of the rods, the flaps resume their
previous angular position and, as the rods move forward are drawn edgewise
through the water with little or no resistance. The angular position of the flaps
to each other is necessary to enable the water, in its effort to thrust the flaps into
the position at right angles to the rods, to have a purchase on their surfaces;
nevertheless the angle between the flaps, during their non-effective stroke, may
actually be more acute than is, for the sake of clearness, represented in Fig. 2.
It is a matter of indifference whether the levers are simultaneously moved in the
same direction or in opposite directions, relatively to each other, inasmuch as on
each side of the hull, in either case, there will always be one operative "thrust-
blade," the other making an idle stroke. On the other hand the operation of one
lever only, will change the direction of the boat, without the co-operating aid of
the steering-gear and rudder.
In the modification, shown in Figs. 4, 5 and 6 each rod c (or c) as in the
preceding example carries a cross-bar d with pivots or hinges e on which the thrust
blades or flaps swing to and fro.
But each rod e (or e) is prolonged beyond by the extension c², on which slides
a sleeve, with which the flaps fare connected by the links 2.
A pin ca in serves as a stop to the sleeve, to limit the backward slope of the
blades, whose operative position is reached when the sleeve f' abuts against the
boss or enlarged part z of the rod c c² (Figs. 4 and 5).
C
In this modification the blades fact in the same way as before described; while
the proper movement of the blades, is assured and supported by their being
connected, and any disturbance of the working is prevented by the guidance and
support thus obtained.!

page_text: Although the inventor has designed the propelling device for use by hand-power,
there is nothing to prevent the employment of a motor in connection therewith.
In this case the motor may be applied either directly to the lever b, or to a shaft
on which said lever is secured with the aid of any known kinematic means. Instead
of the levers bother alternating devices may be employed for ensuring the before
described alternately reciprocating movement of the carriers and flaps.
Should the driving means be of such kind that both the sets of operative devices
can only be worked together and not separately, steering mechanism must
obviously be provided.
Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondent, and in what manner the
same is to be performed, I declare that what I claim is ;-
1. In apparatus for the propulsion or steering of a navigable vessel the
arrangement on each side of the hull of a two armed lever (b) so connected with
two axially or longitudinally reciprocating rods (c c¹) carrying pivoted flaps (f)
, that when one rod in moving backwards opposes its flaps to the water so as to exert
a thrust against it the other rod simultaneously in moving forwards draws its flaps
idly through the water each in a vertical plane nearly parallel with the direction
of movement substantially as described and illustrated in the accompanying
drawings.
2. In apparatus for propelling or steering navigable vessels the combination at
each side of the hull of a two armed lever b two rods c c¹ and a hand lever g
pivotally connected to the lever guides i for the rods a cross bar d on each rod and
two flaps pivoted to each cross bar so as to swing in horizontal planes all arranged
substantially as and operating in the manner described and illustrated in the
accompanying drawings.
3. The combination and arrangement of parts constituting the complete pro-
pelling or steering device for navigable vessels substantially as described and
illustrated in the accompanying drawings.
Dated this 1st day of August 1895
ALFRED J. BOULT,
Chartered Patent Agent.