[0001] The present invention relates to a rudder for a craft, particularly a marine craft.
[0002] The rudder according to the invention comprises a rudder blade and a rudder stock,
which is adapted to be connected to a craft, rotatable around a first axis of rotation.
[0003] A rudder as the above-mentioned, the rudder blade of which is hinged at its front
edge to a stern, is for instance known from
GB 488 043 A. The rudder blade thus rotates substantially around its front edge when the rudder
blade is rotated by the rudder stock. Hence, the rotational axis of the rudder blade
is coincident with the rotational axis of the rudder stock. The rudder blade is positioned
relatively close to and on level with a propeller of a craft.
[0004] Another example of a rudder of the above-mentioned type is disclosed in
GB 373 656 A, wherein a rudder blade is rotatably connected by its front edge to a stern. Here
too, the rudder blade rotates around its front edge when the rudder stock is rotated,
and here too, the rudder blade is positioned next to the propeller of the craft.
[0005] Yet another example of a rudder of the above-mentioned type is disclosed in
US 3,159,132, wherein a rudder for a smaller craft is described. Here, a rudder blade is fixed
to a rudder stock in such a way that the rudder blade rotates around its front edge
when the rudder stock is rotated. Here too, the rudder blade is positioned next to
the propeller of the craft.
[0006] With the above-mentioned type of rudder, the rudder blade will, when it is rotated
from its neutral position into an angled position, lead to that the craft is not responding
very fast or precisely to the performed rotation of the rudder blade. This makes maneuvering
the craft difficult, especially in areas where it is crucial to be able to perform
fast and precise changes in course, such as in harbour areas, in waters with much
water-borne traffic or many rocks, icebergs or other obstacles.
[0007] Another problem with rudders of the above-mentioned type is that the rudder stock,
the rudder blade and their journaling is exposed to large torque loads when the rudder
blade is moved into an angled position. This is due to the journaling of the rudder
blade at its front edge that makes the full length of the rudder blade contribute
to the torque load. This necessitates a robust and strong construction, which results
in a heavy rudder construction that increases the weight of the craft and causes a
poor fuel economy for the craft and/or reduces the loading capacity.
[0008] Furthermore, it is required that the control means of the craft for setting the angular
displacement of the rudder blade are able to overcome the large torques acting on
the journaling of the rudder blade in order to be able to control the angular displacement
of the rudder blade. Therefore, rudders of the above-mentioned type necessitate powerful
hydraulic systems or other kinds of powerful devices for controlling the rudder blade,
which increases the weight of the craft and possibly the complexity of the construction.
[0009] Previous attempts have been made to mitigate some of the above-mentioned problems
by providing a rudder, the rudder stock of which is journaled in the rudder blade
in a distance from the front edge of the rudder blade. An example of such a rudder
is for instance found in
DE 38 14 943 A1.
[0010] Based on the above, it is an object of the present invention to provide a rudder
that provides the craft on which it is mounted with better maneuverability, including
reducing the turning radius of the craft at both high and low speeds, while a more
lightweight rudder construction is provided that can increase the loading capacity
of the craft and/or improve its fuel economy.
[0011] Based on the above, a rudder of the initially mentioned kind is provided, the rudder
being characterized in that the rudder blade is connected to the rudder stock by a
first arm, which is fixed to the rudder stock, so that the rudder blade is rotatable
around a second axis of rotation, which is parallel to and not coincident with the
first axis of rotation, and by a second arm, which provides a third axis of rotation
of the rudder blade, which is parallel to and fixedly positioned in relation to the
first axis of rotation, as the rudder blade is displaceable in relation to and rotatable
around the second axis of rotation and/or the third axis of rotation.
[0012] It is understood that the term "arm" comprises an arm in the meaning: the straight
distance between two points in which forces act; in this case, for the first arm,
the straight distance between the first axis of rotation and the second axis of rotation,
and for the second arm, the straight distance between the first axis of rotation and
the third axis of rotation. The skilled person will understand that these arms can
in practice be provided by a number of various elements, such as for instance an arm-
or rod-shaped element or other differently shaped elements, of which further examples
will be given below.
[0013] As the front edge of the rudder blade according to the invention is not directly
hinged to the rudder stock, a rotation of the rudder stock causes the front edge of
the rudder blade to move to one side, while the aft edge of the rudder stock is moved
to the opposite side, as the rudder blade is always retained at the third axis of
rotation in relation to the first axis of rotation. In this way, when the rudder blade
is mounted next to a propeller of a craft, the rudder blade captures water flow from
both sides of the propeller when the rudder blade is put into an angled position rather
than just from one side of the propeller. Hereby a higher degree of maneuverability
is obtained.
[0014] Furthermore, the fact that the rudder blade is journaled both at the second axis
of rotation and at the third axis of rotation causes the torque loads on each of the
two journalings to be smaller than the load on the journaling of a rudder of the above-mentioned
type of known rudder. This allows for a slimmer and more lightweight construction,
which increases the loading capacity and/or the fuel economy of the craft.
[0015] Furthermore, the construction of the rudder has the effect that the more angled a
position the rudder blade is put into, the closer to the rudder stock the rudder blade
is pulled and thus closer to the propeller of the craft, on which the rudder is intended
to be mounted. This has the effect that the rudder blade can more efficiently capture
a larger part of the water flow from the propeller, since the closer the rudder blade
is to the propeller, the smaller a portion of the flow gets past the rudder blade
unaffected.
[0016] Furthermore, this rudder construction has the effect that the more angled a position
the rudder blade is put into, the larger a portion of the rudder blade will be at
one side of a central plane compared to the other side of the central plane. This
asymmetric positioning in angled positions enables the provision of a relatively long
fin at the aft edge of the rudder blade. Hereby is obtained the possibility of affecting
the propeller flow in very large width at large angular displacements of the rudder.
This provides for the possibility of a very high degree of maneuverability at both
high and low speed of the craft. At low speed the craft is thus provided with the
possibility of substantially rotating around its own axis by the aft propeller alone.
This has previously only been possible by use of lateral propellers on the craft.
[0017] In an embodiment of the rudder, the second axis of rotation and/or the third axis
of rotation is within the rudder blade. To have one or both of these axes within the
rudder blade reduces the presence of protrusions that can create disturbing whirls
and undesirable resistance.
[0018] In an embodiment of the rudder, the shortest distance between the first axis of rotation
and the third axis of rotation is larger than the shortest distance between the first
axis of rotation and the second axis of rotation. This provides for a particularly
advantageous pattern of movement of the rudder blade as a function of the rotation
of the rudder stock.
[0019] In an embodiment of the rudder, the first axis of rotation, seen in an intended direction
of flow of a water flow past the rudder blade in a neutral position of the rudder
blade, is positioned in front of the second axis of rotation, preferably in front
of a front edge of the rudder blade, and the second axis of rotation, seen in the
same direction, is positioned in front of the third axis of rotation, which is preferably
positioned in front of an aft edge of the rudder blade, seen in the same direction.
This provides for a particularly advantageous pattern of movement of the rudder blade
as a function of the rotation of the rudder stock.
[0020] In an embodiment of the rudder, the first arm comprises a first rod-shaped element
extending at least between the first axis of rotation and the second axis of rotation,
and/or the second arm comprises a second rod-shaped element extending at least between
the first axis of rotation and the third axis of rotation and preferably further being
adapted to extend between the first axis of rotation and the craft as a rudder heel.
A rod-shaped element will create little undesirable turbulence around the rudder blade.
The second rod-shaped element furthermore extending as a rudder heel provides stability
and strength to the whole rudder construction, as the rudder is then not just fastened
to the craft at the rudder stock, but also furthermore at the second arm as a rudder
heel.
[0021] In an embodiment of the rudder, the third axis of rotation is provided as a guideway
comprising a pin, which is provided on the second arm so that the longitudinal axis
of the pin is parallel to and coincident with the third axis of rotation, and an oblong
recess provided in the rudder blade so that the rudder blade is rotatable and displaceable
in relation to the second arm as the oblong recess is displaced and/or rotated around
the pin. This is a way to implement the third axis of rotation that provides little
undesirable turbulence around the rudder blade. This is due to the fact that those
parts being in mutual engagement are within the rudder blade, as the pin is completely
or partially within the recess in the rudder blade.
[0022] In an embodiment of the rudder, the rudder comprises a fin hingedly connected to
the rudder blade so that the fin is rotatable in relation to the rudder blade around
a fourth axis of rotation, which is parallel to at least the first axis of rotation,
and the fin is connected to the second arm by a third arm, which is fixed to the fin
so that the fin is rotatable around a fifth axis of rotation, which is not coincident
with the fourth axis of rotation, and the fifth axis of rotation is preferably positioned
between the third axis of rotation and the fourth axis of rotation, seen in the intended
direction of flow of a water flow past the rudder blade in a neutral position of the
rudder blade, as the second arm preferably extends past the third axis of rotation
in a direction away from the first axis of rotation. This connection between the fin
and the other elements of the rudder enables the fin to be put into an angled position
which, together with the corresponding angled position of the rudder blade, renders
the craft on which the rudder is mounted most maneuverable. For instance, an angular
displacement of the fin of more than 90° in relation to neutral position of the fin
is enabled, which has the effect that the craft will be able to turn around its own
axis without use of lateral propellers.
[0023] In an embodiment of the rudder, a rotation of the rudder stock of substantially 7°
in relation to neutral position results in a rotation of the rudder blade of substantially
5°-30°, preferably of 10°-25°, in relation to neutral position and preferably in a
rotation of the fin of substantially 20°-40°, preferably of 25°-35°, in relation to
neutral position, and a rotation of the rudder stock of substantially 15° in relation
to neutral position results in a rotation of the rudder blade of substantially 20°-40°,
preferably of 25°-35°, in relation to neutral position and preferably in a rotation
of the fin of substantially 50°-70°, preferably of 55°-65°, in relation to neutral
position, and a rotation of the rudder stock of substantially 40° in relation to neutral
position results in a rotation of the rudder blade of substantially 35°-55°, preferably
of 40°-50°, in relation to neutral position and preferably in a rotation of the fin
of substantially 95°-115°, preferably of 100°-110°, in relation to neutral position.
These correlated angles provide the craft on which the rudder is mounted with good
maneuverability at both high and low speed. By rotating the rudder stock by 40°, the
fin is put into a position angled by more than 90° and positioned substantially on
one side of the central plane, while the rudder blade is substantially positioned
on the other side of the central plane. This implies that the direction of flow of
a large part of the water flow is redirected to a greater or lesser extent, whereby
the turning radius of the craft on which the rudder is intended to be mounted is reduced
considerably. At low speed this will enable the craft to almost turn on the spot.
[0024] In an embodiment of the rudder, the rudder blade is adapted to be positioned substantially
next to a propeller of a craft, preferably next to an aft propeller of a -craft, preferably
with the first axis of rotation and the third axis of rotation being in line next
to the center of the propeller. The water flow across the rudder is greatest directly
next to the propeller, and the largest compressive and tensile forces acting on the
rudder blade are generated at this position in relation to the propeller of the craft.
Thus, this position gives the most efficient utilization of the rudder blade and thus
the best maneuverability of the craft.
[0025] In an embodiment of the rudder, the front edge of the rudder blade in neutral position
of the rudder blade is positioned in a distance from the first axis of rotation, and/or
the aft edge of the rudder blade is in neutral position of the rudder blade positioned
in a distance from the third axis of rotation. The distance between the front edge
of the rudder blade and the first axis of rotation in neutral position of the rudder
blade is preferably just a little larger than the radius of the rudder stock so that
the front edge of the rudder blade is close the rudder stock in neutral position of
the rudder blade, but is still able to pass by the rudder stock when the rudder blade
is put into an angled position. The short distance between the front edge of the rudder
blade and the rudder stock in neutral position of the rudder blade is advantageous
as this construction creates little undesirable turbulence in neutral position of
the rudder blade and allows for an influence on the water flow in a large width in
angled positions of the rudder blade. The aft edge of the rudder blade is preferably
positioned behind the third axis of rotation seen in the direction of flow, and the
distance between the aft edge of the rudder blade and the third axis of rotation in
neutral position of the rudder blade is preferably between ¼ and ¾ of the length of
the rudder blade. Hereby is obtained that the front portion of the rudder blade in
an angled position captures an appropriate quantity of the water flow from one side
of the propeller, while the rear portion of the rudder blade in an angled position
captures an appropriate quantity of the water flow from the other side of the propeller.
[0026] In the following, embodiments of the rudder for a craft according to the invention
will be described in closer detail with reference to the accompanying figures, where
Fig. 1 is a schematic representation of a first embodiment of the rudder according
to the invention seen from the side, the rudder blade being in neutral position and
mounted on a craft,
Fig. 2 is a schematic representation of the rudder according to the first embodiment
seen from above, the rudder blade being in neutral position,
Fig. 3 is a schematic representation of the rudder according to the first embodiment
seen from above, the rudder blade being in a slightly angled position,
Fig. 4 is a schematic representation of the rudder according to the first embodiment
seen from above, the rudder blade being in a more angled position than shown in Fig.
3,
Fig. 5 is a schematic representation of the rudder according to the first embodiment
seen from above, the rudder blade being in an even more angled position than shown
in Fig. 4,
Fig. 6 is a schematic representation of the rudder according to a second embodiment
seen from the side, the rudder blade being in neutral position and mounted on a craft,
Fig. 7 is a schematic representation of the rudder according to the second embodiment
seen from above, the rudder blade being in neutral position, and
Fig. 8 is a schematic representation of the rudder according to the second embodiment
seen from above, the rudder blade being in an angled position.
[0027] Similar features in the figures are denoted with the same reference signs. For the
sake of lucidity, the rudder is depicted transparent in the figures 2 to 5 and 7 to
8 so that the mutual relations between the individual elements of the rudder are clearly
visible.
[0028] In this specification, the term "neutral position" of the rudder blade denotes the
position in which the second arm is parallel to and within a longitudinal central
plane of the rudder blade. When the rudder is mounted on a craft this position will
usually be parallel to an upright, longitudinal central plane of the craft.
[0029] The "central plane" is the upright, longitudinal plane, within which the longitudinal
central plane of the rudder blade substantially is in neutral position.
[0030] The term "angled position" denotes all those positions of the rudder blade, wherein
the longitudinal central plane of the rudder blade is not parallel to and does not
contain the second arm. When the rudder is mounted on a craft this will mean all those
positions of the rudder blade, wherein the longitudinal central plane of the rudder
blade is not parallel to the upright longitudinal plane of the craft, i.e. those positions
of the rudder blade where it is rotated to the starboard or the port side.
[0031] The term "the angular displacement of the rudder blade" denotes the angle between
the longitudinal central plane of the rudder blade in the neutral position of the
rudder blade and in an angled position of the rudder blade.
[0032] The term "the length of the rudder blade" denotes the distance along the longitudinal
central plane of the rudder blade from a front edge of the rudder blade to an aft
edge of the rudder blade.
[0033] The term "the height of the rudder blade" denotes the distance along the longitudinal
central plane of the rudder blade from an upper edge of the rudder blade to a lower
edge of the rudder blade.
[0034] The term "neutral position of the fin" denotes the position of the fin, wherein its
upright longitudinal plane is substantially coincident with the upright longitudinal
plane of the rudder blade in its neutral position.
[0035] Depending on the further design of the rudder blade, the front edge, aft edge, upper
edge and/or lower edge may be shaped as faces rather than actual edges. Thus, it is
understood that "front edge", "aft edge", "upper edge" and/or "lower edge" may be
configured as faces.
[0036] The term "next to" denotes that the rudder blade is directly behind the propeller
seen in the general direction of flow of a water flow from the propeller in operation.
[0037] In Fig. 1 an embodiment of the rudder 2 according to the invention is shown. The
rudder 2 is mounted on a craft 1, of which only its stern is indicated in Fig. 1.
The rudder 2 comprises a rudder blade 3 and a rudder stock 4. The rudder stock 4 is
seen to be connected to the craft 1 rotatably around a first axis of rotation 5. The
rudder stock 4 is rotated by means of control means on or in the craft, such as a
steering wheel, a control stick, a joystick or other means (not depicted). Although
the aft propeller of the craft 1 is not depicted in the figures 1 to 5, the rudder
blade 3 is adapted to be placed substantially next to the aft propeller of the craft.
However, it is conceivable that the rudder blade is placed next to other types of
propellers of a craft than the aft propeller, such as for instance lateral propellers
or front propellers. The rudder blade may also be mounted at other locations than
next to the propeller(s) of the craft or on crafts without propellers, such as sailboats
or crafts that are propelled by oars or the like.
[0038] The rudder stock 4 is positioned outside of the rudder blade 3. The rudder blade
3 is connected to the rudder stock 4 by two first arms 6, each of which being fixed
to the rudder stock 4. Hence, the two first arms 6 are not moveable in relation to
the rudder stock 4. The two first arms 6 are rotatably connected to the rudder blade
3 so that the rudder blade 3 is rotatable around a second axis of rotation 7, which
is parallel to and not coincident with the first axis of rotation 5.
[0039] It is seen that both of the first arms 6 are shaped as rod-shaped elements 12 extending
between the first axis of rotation 5 and the second axis of rotation 7, i.e. between
the rudder stock 4 and the journaling 23 of the first arms 6 in the rudder blade 3.
It is understood that the first arms do not necessarily have to be rod-shaped but
may take other shapes, such as for instance crescent-shaped or curved. They could
also be protrusions on the rudder stock or variations in its diameter, such as tooth-shaped,
disc-shaped, cylinder-shaped or polygonal protrusions on the rudder stock, as long
as the first arms provide a distance between the first axis of rotation 5 and the
second axis of rotation 7. Irrespective of their shape, the first arms 6 do not need
to be parallel as long as they provide a second axis of rotation 7 that is parallel
to but not coincident with the first axis of rotation 5.
[0040] Although the depicted embodiment of the rudder 2 is provided with two first arms
6, it is understood that just one first arm, or even more first arms, may be provided.
In the latter case, if one or more first arms are to be placed between the two first
arms 6 depicted in the embodiment in Fig. 1, it may be necessary with a shape of the
first arms 6 that allow movement of the rudder blade to the sides so that the one
or more arms placed there does not impede movement of the rudder blade 3. Alternatively,
notches or recesses in the rudder blade may be provided allowing the first arms to
pass through the rudder blade during its movement to the sides.
[0041] In the embodiment of Fig. 1, a second arm 8 is furthermore provided, which provides
a third axis of rotation 9, which is parallel to and fixedly positioned in relation
to the first axis of rotation 5. It is understood that the "second arm" should be
read in the sense given above, i.e. the straight distance between two points in which
forces act. In the depicted embodiment, the second arm 8 is implemented partly by
a rod-shaped element 13 at the lower edge of the rudder blade 3 and partly by a sort
of suspension at the upper edge of the rudder blade 3. Embodiments of the rudder where
the second arm 8 is provided solely by a suspension or by one or more rod-shaped elements
13 are conceivable.
[0042] The rudder blade 3 is displaceable in relation to and rotatable around the third
axis of rotation 9, which is provided as a guideway 15. In the following, the guideway
15 at the lower edge of the rudder blade will be described in more detail. It is understood
that something similar applies for the guideway 15 provided at the upper edge of the
rudder blade. The guideway 15 comprises a pin 16, which is provided at the second
arm 8 so that the longitudinal axis 17 of the pin 16 is parallel to and coincident
with the third axis of rotation 9. As is best seen in Figs 2 to 5, the guideway 15
furthermore comprises an oblong recess 18 provided in a lower (upper, respectively)
face of the rudder blade 3 in such a way that the rudder blade 3 is rotatable and
displaceable in relation to the second rod-shaped element 13, as the oblong recess
18 is displaced and rotated around the pin 16 by rotation of the rudder blade 3.
[0043] The slidable and rotatable journaling of the rudder blade at the third axis of rotation
may be configured in other ways. For instance, the pin may be provided in the rudder
blade rather than in the second rod-shaped element 13, and the oblong recess may correspondingly
be provided in the second rod-shaped element 13 rather than in the rudder blade. Other
alternative solutions are conceivable, such as a fork-shaped pin being provided at
the second rod-shaped element 13 rotatable in relation thereto, between the two fork
legs of which the rudder blade is displaceable.
[0044] In the depicted embodiment, the rod-shaped element 13 extends between the third axis
of rotation 9 and the craft 1 as a rudder heel 14. It is understood that the rod-shaped
element 13 does not necessarily have to extend all the way to the craft as a rudder
heel. The rod-shaped element may just extend between the first axis of rotation and
the third axis of rotation. In that case, it will be expedient with an upper construction
that is strong enough for the rudder to be suspended from it at the craft. Also, it
is understood that there may be provided two rod-shaped elements 13; one above and
one below the rudder blade.
[0045] As is best seen from the figures 2 to 5, the third axis of rotation 9 is within the
rudder blade 3. The shortest distance a
1-3 between the first axis of rotation 5 and the third axis of rotation 9 is seen to
be larger than the shortest distance a
1-2 between the first axis of rotation 5 and the second axis of rotation 7.
[0046] As is seen from Fig. 2, the first axis of rotation 5, seen in the direction of flow
r
s of a water flow past the rudder blade 3 in a neutral position of the rudder blade
3, is placed in front of the second axis of rotation 7 and in front of a front edge
10 of the rudder blade 3. The second axis of rotation 7, seen in the same direction,
is placed in front of the third axis of rotation 9, which is placed in front of an
aft edge 11 of the rudder blade 3 seen in the same direction.
[0047] With regard to the distance between the front edge 10 of the rudder blade 3 and the
first axis of rotation 5 in neutral position of the rudder blade 3, it is only slightly
larger than the radius of the rudder stock 4 so that the front edge 10 of the rudder
blade 3 is close to the rudder stock 4 in neutral position of the rudder blade 3 but
is still able to pass the rudder stock 4, when the rudder blade 3 is put into an angled
position. In the depicted embodiment, the distance between the aft edge 11 of the
rudder blade 3 and the third axis of rotation 9 in neutral position of the rudder
blade 3 make up 4/10-5/10 of the length of the rudder blade 3. Embodiments of the
rudder where these distances are different from the above-described are conceivable.
[0048] The rudder 2 is provided with a fin 19, which is hingedly connected to the rudder
blade 3 so that the fin 19 is rotatable in relation to the rudder blade 3 around a
fourth axis of rotation 20, which is parallel to at least the first axis of rotation
5. The fin 19 is connected to the second arm 8 by a third arm 21. The third arm 21
is fixed to the fin 19 along a lower edge of the fin 19 and is rotatably connected
to the second arm 8 so that the fin 19 is rotatable around a fifth axis of rotation
22, which is not coincident with the fourth axis of rotation 20. In the depicted embodiment,
the fifth axis of rotation 22 is not coincident with any of the other axes of rotation
5, 7, 9, 20. In the depicted embodiment, the second arm 8 extends in the direction
r
s from the first axis of rotation 5 past the third axis of rotation 9 and towards the
fourth axis of rotation 20. Hence, the fifth axis of rotation 22 is between the third
axis of rotation 9 and the fourth axis of rotation 20, as the third arm 21 is journaled
there in the second arm 8. The third arm 21 is provided in the shape of a cornered,
rod-shaped element, whose first leg 21a extends along a length of the fin 19, and
whose second leg 21b extends parallel to and coincident with the fifth axis of rotation
22. It is understood, as also mentioned in relation to the provision of the second
arm, that also a third arm at the upper edge of the rudder blade may be provided depending
on the further construction and suspension of the rudder. It is furthermore understood
that the third arm may take on other shapes in other embodiments of the rudder, as
it was also mentioned in connection with the first arms. Embodiments of the rudder
with no fin are conceivable.
[0049] As best seen in Fig. 1, the length of the rudder blade 3 makes up approximately ¾
of the total length of rudder blade 3 and fin 19, and the fin 19 makes up the remaining
¼. It is understood that this relation may vary for different embodiments of the invention.
Hence, the rudder blade may make up between ½ and all of the total length of the rudder
blade and fin altogether, and the fin correspondingly between ½ and none of the total
length of rudder blade and fin.
[0050] The rudder is intended for use with a wide range of different types and sizes of
crafts and is intended to be adapted by scaling of its dimensions. Hence, the height
of the rudder blade and fin will typically be between 20 cm and 15 m, the length of
the rudder blade between 20 cm and 7 m, and the length of the fin between 5 cm and
3 m. The dimensions in the lower regions of the ranges will be suitable for smaller
crafts, such as dinghies, while the dimensions in the upper regions of the ranges
will be suitable for larger crafts, such as cruisers, tankers and container carriers.
[0051] Notwithstanding the absolute dimensions of the rudder, it is advantageous with a
particular correlation between a given rotation of the rudder stock and the resulting
rotation of the rudder blade and the fin, which correlation is obtained by an appropriate
mutual positioning of the first, second, third, fourth and fifth axis of rotation.
As is seen from the figures, the distance between the first and the second axis of
rotation make up approximately 2/5 of the distance between the first and the fourth
axis of rotation, while the distance between the first and the third axis of rotation
make up approximately 3/5 of the distance between the first and the fourth axis of
rotation, and the distance between the first and the fifth axis of rotation make up
approximately 4/5 of the distance between the first and the fourth axis of rotation.
It is understood that the above-mentioned advantages of the rudder will be obtained
within certain ranges of these relative mutual distances. Hence, the distance between
the first and the second axis of rotation may vary between 1/5 and 3/5 of the distance
between the first and the fourth axis of rotation, the distance between the first
and the third axis of rotation between 2/5 and 4/5 of the distance between the first
and the fourth axis of rotation, and the distance between the first and the fifth
axis of rotation between 3/5 and 9/10 of the distance between the first and the fourth
axis of rotation.
[0052] Figures 2 to 5 exemplify a correlation between the angular displacement v
s of the rudder stock 4 and the resulting angular displacement v
b of the rudder blade 3 and angular displacement v
f of the fin 19. Figures 2 to 5 show the rudder 2 in positions of increasing angular
displacement of the rudder blade 3 and the fin 19. In Fig. 2 the rudder blade 3 and
the fin 19 are depicted in their neutral positions, where the angular displacement
of rudder stock v
s, rudder blade v
b and fin v
f is zero. In Fig. 3 the rudder stock 4 has been rotated by v
s=7° clockwise out of the neutral position. As is seen, it has resulted in a rotation
of the rudder blade 3 in relation to neutral position of v
b = about 17° and in a rotation of the fin 19 in relation to neutral position of v
f = about 32°. In Fig. 4 the rudder stock 4 has been rotated by v
s=15° clockwise out of the neutral position. This has resulted in a rotation of the
rudder blade 3 in relation to neutral position of v
b = about 30° and in a rotation of the fin 19 in relation to neutral position of v
f = about 58°. In Fig. 5 the rudder stock 4 has been rotated by v
s=40° clockwise out of the neutral position. As is seen, it has resulted in a rotation
of the rudder blade 3 in relation to neutral position of v
b = about 44° and in a rotation of the fin 19 in relation to neutral position of v
f = about 106°. The skilled person will understand that an angular displacement of
the rudder stock resulting in differently angled positions of rudder blade and fin
than the above-mentioned will be acceptable and still at least to some degree provide
the above-mentioned advantages with regard to better maneuverability, reduction of
turning radius etc. Particularly for embodiments of the rudder where no fin is provided
it may be desirable to have larger angular displacements of the rudder blade at smaller
angular displacements of the rudder stock than exemplified above.
[0053] Figures 6 to 8 show another embodiment of the rudder 2 according to the invention.
The rudder 2 is seen to be of a broadly similar construction as the rudder according
to the first embodiment. Hence, in the following, focus will be on the differences.
[0054] As is seen, the rudder blade 3 according to the second embodiment is rotatable around
and displaceable in relation to the second axis of rotation 7 and rotatable around
the third axis of rotation 9. Embodiments of the rudder, where the rudder blade is
rotatable around and displaceable in relation to the second axis of rotation as well
as the third axis of rotation are also conceivable.
[0055] Furthermore, the rudder 2 according to the second embodiment is seen to be fastened
to the craft 1 solely by the rudder stock 4 and the rudder heel 14. It is understood
that the rudder according to the second embodiment also may be fastened to the craft
in the same way as the first embodiment and vice versa.
List of reference signs:
[0056]
- 1
- Craft
- 2
- Rudder
- 3
- Rudder blade
- 4
- Rudder stock
- 5
- First axis of rotation
- 6
- First arm
- 7
- Second axis of rotation
- 8
- Second arm
- 9
- Third axis of rotation
- 10
- Front edge of rudder blade
- 11
- Aft edge of rudder blade
- 12
- First rod-shaped element
- 13
- Second rod-shaped element
- 14
- Rudder heel
- 15
- Guideway
- 16
- Pin
- 17
- Longitudinal axis of pin
- 18
- Oblong recess
- 19
- Fin
- 20
- Fourth axis of rotation
- 21
- Third arm
- 21a
- First leg of third arm
- 21b
- Second leg of third arm
- 22
- Fifth axis of rotation
- 23
- Journaling of first arm in rudder blade
- a1-3
- Shortest distance between first and third axis of rotation
- a1-2
- Shortest distance between first and second axis of rotation
- rs
- Direction of flow
- vs
- Angular displacement of rudder stock
- vb
- Angular displacement of rudder blade
- vf
- Angular displacement of fin
1. A rudder (2) for a craft (1), which rudder (2) comprises a rudder blade (3) and a
rudder stock (4), which is adapted to be connected to a craft, (1) rotatable around
a first axis of rotation (5),
characterized by
the rudder blade (3) being connected to the rudder stock (4) by a first arm (6), which
is fixed to the rudder stock (4) so that the rudder blade (3) is rotatable around
a second axis of rotation (7), which is parallel to and not coincident with the first
axis of rotation (5), and
by a second arm (8) providing a third axis of rotation (9) of the rudder blade (3),
which is parallel to and fixedly positioned in relation to the first axis of rotation
(5) as the rudder blade (3) is displaceable in relation to and rotatable around the
second axis of rotation (7) and/or the third axis of rotation (9).
2. A rudder (2) according to claim 1, wherein the second axis of rotation (7) and/or
the third axis of rotation (9) is within the rudder blade (3).
3. A rudder (2) according to claim 1 or 2, wherein the shortest distance (a1-3) between the first axis of rotation (5) and the third axis of rotation (9) is larger
than the shortest distance (a1-2) between the first axis of rotation (5) and the second axis of rotation (7).
4. A rudder (2) according to any of the preceding claims, wherein the first axis of rotation
(5), seen in an intended direction of flow (rs) of a water flow past the rudder blade (3) in a neutral position of the rudder blade
(3), is positioned in front of the second axis of rotation (7), preferably in front
of a front edge (10) of the rudder blade (3), and wherein the second axis of rotation
(7), seen in the same direction, is positioned in front of the third axis of rotation
(9), which is preferably positioned in front of an aft edge (11) of the rudder blade
(3), seen in the same direction.
5. A rudder (2) according to any of the preceding claims, wherein the first arm (6) comprises
a first rod-shaped element (12) extending at least between the first axis of rotation
(5) and the second axis of rotation (7),
and/or wherein the second arm (8) comprises a second rod-shaped element (13) extending
at least between the first axis of rotation (5) and the third axis of rotation (9)
and preferably further being adapted to extend between the first axis of rotation
(5) and the craft (1) as a rudder heel (14).
6. A rudder (2) according to any of the preceding claims, wherein the third axis of rotation
(9) is provided as a guideway (15) comprising
a pin (16) provided on the second arm (8) so that the longitudinal axis (17) of the
pin (16) is parallel to and coincident with the third axis of rotation (9), and
an oblong recess (18) provided in the rudder blade (3) so that the rudder blade (3)
is rotatable and displaceable in relation to the second arm (8) as the oblong recess
(18) is displaced and/or rotates around the pin (16).
7. A rudder (2) according to any of the previous claims, wherein the rudder (2) comprises
a rudder fin (19) hingedly connected to the rudder blade (3) so that the fin (19)
is rotatable in relation to the rudder blade (3) around a fourth axis of rotation
(20), which is parallel to at least the first axis of rotation (5), and
wherein the fin (19) is connected to the second arm (8) by a third arm (21), which
is fixed to the fin (19) so that the fin (19) is rotatable around a fifth axis of
rotation (22), which is not coincident with the fourth axis of rotation (20), and
wherein the fifth axis of rotation (22) is preferably positioned between the third
axis of rotation (9) and the fourth axis of rotation (20), seen in the intended direction
of flow (rs) of a water flow past the rudder blade (3) in a neutral position of the rudder blade
(3), as the second arm (8) preferably extends past the third axis of rotation (9)
in a direction away from the first axis of rotation (5).
8. A rudder (2) according to any of the preceding claims, wherein a rotation of the rudder
stock (4) of substantially 7° in relation to neutral position results in a rotation
of the rudder blade (3) of substantially 5°-30°, preferably of 10°-25°, in relation
to neutral position and preferably in a rotation of the fin (19) of substantially
20°-40°, preferably of 25°-35°, in relation to neutral position, and
wherein a rotation of the rudder stock (4) of substantially 15° in relation to neutral
position results in a rotation of the rudder blade (3) of substantially 20°-40°, preferably
of 25°-35°, in relation to neutral position and preferably in a rotation of the fin
(19) of substantially 50°-70°, preferably of 55°-65°, in relation to neutral position,
and
wherein a rotation of the rudder stock (4) of substantially 40° in relation to neutral
position results in a rotation of the rudder blade (3) of substantially 35°-55°, preferably
of 40°-50°, in relation to neutral position and preferably in a rotation of the fin
(19) of substantially 95°-115°, preferably of 100°-110°, in relation to neutral position.
9. A rudder (2) according to any of the preceding claims, wherein the rudder blade (3)
is adapted to be positioned substantially next to a propeller of a craft (1), preferably
next to an aft propeller of a craft (1), preferably with the first axis of rotation
(5) and the third axis of rotation (9) being in line next to the center of the propeller.
10. A rudder (2) according to any of the preceding claims, wherein the front edge (10)
of the rudder blade (3) in neutral position of the rudder blade (3) is positioned
in a distance from the first axis of rotation (5), and/or wherein the aft edge (11)
of the rudder blade (3) in neutral position of the rudder blade (3) is positioned
in a distance from the third axis of rotation (9).
1. Steuerruder (2) für ein Schiff (1), wobei dieses Steuerruder (2) ein Ruderblatt (3)
und einen Ruderschaft (4), welcher dazu eingerichtet ist, mit einem Schiff (1) verbunden
zu werden, und um eine erste Drehachse (5) drehbar ist, aufweist,
gekennzeichnet
dadurch, dass das Ruderblatt (3) mit dem Ruderschaft (4) durch einen ersten Arm (6) verbunden ist,
welcher an dem Ruderschaft (4) befestigt ist, so dass das Ruderblatt (3) um eine zweite
Drehachse (7) drehbar ist, welche zu der ersten Drehachse (5) parallel ist und nicht
mit ihr zusammenfällt, und
durch einen zweiten Arm (8), welcher eine dritte Drehachse (9) des Ruderblattes (3)
zur Verfügung stellt, welche zu der ersten Drehachse (5) parallel ist und bezüglich
dieser fest positioniert ist, wobei das Ruderblatt (3) bezüglich der zweiten Drehachse
(7) und/oder der dritten Drehachse (9) verschiebbar und um diese drehbar ist.
2. Steuerruder (2) nach Anspruch 1, wobei sich die zweite Drehachse (7) und/oder die
dritte Drehachse (9) innerhalb des Ruderblattes (3) befindet.
3. Steuerruder (2) nach Anspruch 1 oder 2, wobei der kürzeste Abstand (a1-3) zwischen der ersten Drehachse (5) und der dritten Drehachse (9) größer als der kürzeste
Abstand (a1-2) zwischen der ersten Drehachse (5) und der zweiten Drehachse (7) ist.
4. Steuerruder (2) nach einem der vorhergehenden Ansprüche, wobei die erste Drehachse
(5), in einer beabsichtigten Strömungsrichtung (rs) eines Wasserstroms an dem Ruderblatt (3) vorbei in einer neutralen Position des
Ruderblattes (3) gesehen, vor der zweiten Drehachse (7) positioniert ist, vorzugsweise
vor einer Vorderkante (10) des Ruderblattes (3), und wobei die zweite Drehachse (7),
in derselben Richtung gesehen, vor der dritten Drehachse (9) positioniert ist, welche
vorzugsweise vor einer Hinterkante (11) des Ruderblattes (3) positioniert ist, in
derselben Richtung gesehen.
5. Steuerruder (2) nach einem der vorhergehenden Ansprüche, wobei der erste Arm (6) ein
erstes stangenförmiges Element (12) aufweist, das sich wenigstens zwischen der ersten
Drehachse (5) und der zweiten Drehachse (7) erstreckt,
und/oder wobei der zweite Arm (8) ein zweites stangenförmiges Element (13) aufweist,
das sich wenigstens zwischen der ersten Drehachse (5) und der dritten Drehachse (9)
erstreckt und vorzugsweise ferner dazu eingerichtet ist, sich zwischen der ersten
Drehachse (5) und dem Schiff (1) als eine Ruderhacke (14) zu erstrecken.
6. Steuerruder (2) nach einem der vorhergehenden Ansprüche, wobei die dritte Drehachse
(9) als eine Führungsbahn (15) vorgesehen ist, welche aufweist:
einen Bolzen (16), der an dem zweiten Arm (8) vorgesehen ist, so dass die Längsachse
(17) des Bolzens (16) parallel zu der dritten Drehachse (9) ist und mit dieser zusammenfällt,
und
eine längliche Vertiefung (18), die in dem Ruderblatt (3) vorgesehen ist, so dass
das Ruderblatt (3) bezüglich des zweiten Armes (8) drehbar und verschiebbar ist, wenn
die längliche Vertiefung (18) verschoben wird und/oder sich um den Bolzen (16) dreht.
7. Steuerruder (2) nach einem der vorhergehenden Ansprüche, wobei das Steuerruder (2)
eine Ruderflosse (19) aufweist, die mit dem Ruderblatt (3) gelenkig verbunden ist,
so dass die Flosse (19) bezüglich des Ruderblattes (3) um eine vierte Drehachse (20)
drehbar ist, welche wenigstens zu der ersten Drehachse (5) parallel ist, und
wobei die Flosse (19) mit dem zweiten Arm (8) durch einen dritten Arm (21) verbunden
ist, welcher an der Flosse (19) befestigt ist, so dass die Flosse (19) um eine fünfte
Drehachse (22) drehbar ist, welche nicht mit der vierten Drehachse (20) zusammenfällt,
und
wobei die fünfte Drehachse (22) vorzugsweise zwischen der dritten Drehachse (9) und
der vierten Drehachse (20), in der beabsichtigten Strömungsrichtung (rs) eines Wasserstroms an dem Ruderblatt (3) vorbei in einer neutralen Position des
Ruderblattes (3) gesehen, positioniert ist, wobei sich der zweite Arm (8) vorzugsweise
an der dritten Drehachse (9) vorbei in einer Richtung weg von der ersten Drehachse
(5) erstreckt.
8. Steuerruder (2) nach einem der vorhergehenden Ansprüche, wobei eine Drehung des Ruderschaftes
(4) von im Wesentlichen 7° bezüglich der neutralen Position eine Drehung des Ruderblattes
(3) von im Wesentlichen 5°-30°, vorzugsweise von 10°-25°, bezüglich der neutralen
Position und vorzugsweise eine Drehung der Flosse (19) von im Wesentlichen 20°-40°,
vorzugsweise von 25°-35°, bezüglich der neutralen Position zur Folge hat, und
wobei eine Drehung des Ruderschaftes (4) von im Wesentlichen 15° bezüglich der neutralen
Position eine Drehung des Ruderblattes (3) von im Wesentlichen 20°-40°, vorzugsweise
von 25°-35°, bezüglich der neutralen Position und vorzugsweise eine Drehung der Flosse
(19) von im Wesentlichen 50°-70°, vorzugsweise von 55°-65°, bezüglich der neutralen
Position zur Folge hat, und
wobei eine Drehung des Ruderschaftes (4) von im Wesentlichen 40° bezüglich der neutralen
Position eine Drehung des Ruderblattes (3) von im Wesentlichen 35°-55°, vorzugsweise
von 40°-50°, bezüglich der neutralen Position und vorzugsweise eine Drehung der Flosse
(19) von im Wesentlichen 95°-115°, vorzugsweise von 100°-110°, bezüglich der neutralen
Position zur Folge hat.
9. Steuerruder (2) nach einem der vorhergehenden Ansprüche, wobei das Ruderblatt (3)
dazu eingerichtet ist, im Wesentlichen neben einem Propeller eines Schiffes (1) positioniert
zu werden, vorzugsweise neben einem hinteren Propeller eines Schiffes (1), wobei vorzugsweise
die erste Drehachse (5) und die dritte Drehachse (9) in einer Linie neben dem Mittelpunkt
des Propellers angeordnet sind.
10. Steuerruder (2) nach einem der vorhergehenden Ansprüche, wobei die Vorderkante (10)
des Ruderblattes (3) in der neutralen Position des Ruderblattes (3) in einem Abstand
von der ersten Drehachse (5) positioniert ist, und/oder wobei die Hinterkante (11)
des Ruderblattes (3) in der neutralen Position des Ruderblattes (3) in einem Abstand
von der dritten Drehachse (9) positioniert ist.
1. Gouvernail (2) pour un navire (1), ledit gouvernail (2) comprenant un safran de gouvernail
(3) et une mèche de gouvernail (4), qui est conçue pour être raccordée à un navire
(1), rotative autour d'un premier axe de rotation (5), caractérisé en ce que
le safran de gouvernail (3) est raccordé à la mèche de gouvernail (4) par un premier
bras (6), qui est fixé à la mèche de gouvernail (4) de telle sorte que le safran de
gouvernail (3) soit rotatif autour d'un deuxième axe de rotation (7), qui est parallèle
au premier axe de rotation (5) et ne coïncide pas avec celui-ci, et
en ce qu'un deuxième bras (8) produit un troisième axe de rotation (9) du safran de gouvernail
(3), qui est parallèle au premier axe de rotation (5) et positionné de manière fixe
par rapport à celui-ci étant donné que le safran de gouvernail (3) est déplaçable
vis-à-vis, et rotatif autour, du deuxième axe de rotation (7) et/ou du troisième axe
de rotation (9).
2. Gouvernail (2) selon la revendication 1, le deuxième axe de rotation (7) et/ou le
troisième axe de rotation (9) étant situés dans le safran de gouvernail (3).
3. Gouvernail (2) selon la revendication 1 ou 2, la distance la plus courte (a1-3) entre le premier axe de rotation (5) et le troisième axe de rotation (9) étant plus
grande que la distance la plus courte (a1-2) entre le premier axe de rotation (5) et le deuxième axe de rotation (7).
4. Gouvernail (2) selon l'une quelconque des revendications précédentes, le premier axe
de rotation (5), observé dans une direction d'écoulement souhaitée (rs) d'un flux d'eau s'écoulant le long du safran de gouvernail (3) dans une position
neutre du safran de gouvernail (3), étant positionné devant le deuxième axe de rotation
(7), de préférence devant un bord avant (10) du safran de gouvernail (3), et le deuxième
axe de rotation (7), observé dans la même direction, étant positionné devant le troisième
axe de rotation (9), qui est de préférence positionné devant un bord arrière (11)
du safran de gouvernail (3), observé dans la même direction.
5. Gouvernail (2) selon l'une quelconque des revendications précédentes, le premier bras
(6) comprenant un premier élément en forme de tige (12) s'étendant au moins entre
le premier axe de rotation (5) et le deuxième axe de rotation (7), et/ou le deuxième
bras (8) comprenant un deuxième élément en forme de tige (13) s'étendant au moins
entre le premier axe de rotation (5) et le troisième axe de rotation (9) et étant
de préférence en outre conçu pour s'étendre entre le premier axe de rotation (5) et
le navire (1) de façon à constituer un talon de gouvernail (14).
6. Gouvernail (2) selon 1"une quelconque des revendications précédentes, le troisième
axe de rotation (9) étant réalisé de sorte qu'il constitue un guide (15) comprenant
une goupille (16) disposée sur le deuxième bras (8) de telle sorte que l'axe longitudinal
(17) de la goupille (16) soit parallèle au troisième axe de rotation (9) et coïncide
avec celui-ci, et
une cavité oblongue (18) réalisée dans le safran de gouvernail (3) de telle sorte
que le safran de gouvernail (3) soit rotatif et déplaçable par rapport au deuxième
bras (8) lorsque la cavité oblongue (18) est déplacée et/ou pivotée autour de la goupille
(16).
7. Gouvernail (2) selon l'une quelconque des revendications précédentes, le gouvernail
(2) comprenant un aileron de gouvernail (19) raccordé de manière articulée au safran
de gouvernail (3) de telle sorte que l'aileron (19) soit rotatif par rapport au safran
de gouvernail (3) autour d'un quatrième axe de rotation (20), qui est parallèle au
moins au premier axe de rotation (5), et l'aileron (19) étant raccordé au deuxième
bras (8) par un troisième bras (21), qui est fixé à l'aileron (19) de telle sorte
que l'aileron (19) soit rotatif autour d'un cinquième axe de rotation (22), qui ne
coïncide pas avec le quatrième axe de rotation (20), et
le cinquième axe de rotation (22), observé dans la direction d'écoulement souhaitée
(rs) d'un flux d'eau s'écoulant le long du safran de gouvernail (3) dans une position
neutre du safran de gouvernail (3), étant de préférence positionné entre le troisième
axe de rotation (9) et le quatrième axe de rotation (20), étant donné que le deuxième
bras (8) s'étend de préférence au-delà du troisième axe de rotation (9) dans une direction
s'éloignant du premier axe de rotation (5).
8. Gouvernail (2) selon l'une quelconque des revendications précédentes, une rotation
de la mèche de gouvernail (4) de pratiquement 7° par rapport à la position neutre
se traduisant par une rotation du safran de gouvernail (3) de pratiquement 5° à 30°,
de préférence de 10° à 25°, par rapport à la position neutre et de préférence par
une rotation de l'aileron (19) de pratiquement 20° à 40°, de préférence 25° à 35°,
par rapport à la position neutre, et
une rotation de la mèche de gouvernail (4) de pratiquement 15° par rapport à la position
neutre se traduisant par une rotation du safran de gouvernail (3) de pratiquement
20° à 40°, de préférence de 25° à 35°, par rapport à la position neutre et de préférence
par une rotation de l'aileron (19) de pratiquement 50° à 70°, de préférence de 55°
à 65°, par rapport à la position neutre, et
une rotation de la mèche de gouvernail (4) de pratiquement 40° par rapport à la position
neutre se traduisant par une rotation du safran de gouvernail (3) de pratiquement
35° à 55°, de préférence de 40° à 50°, par rapport à la position neutre et de préférence
par une rotation de l'aileron (19) de pratiquement 95° à 115°, de préférence de 100°
à 110°, par rapport à la position neutre.
9. Gouvernail (2) selon l'une quelconque des revendications précédentes, le safran de
gouvernail (3) étant conçu pour être positionné essentiellement à côté d'une hélice
d'un navire (1), de préférence à côté d'une hélice arrière d'un navire (1), le premier
axe de rotation (5) et le troisième axe de rotation (9) étant de préférence alignés
à côté du centre de l'hélice.
10. Gouvernail (2) selon l'une quelconque des revendications précédentes, le bord avant
(10) du safran de gouvernail (3) dans la position neutre du safran de gouvernail (3)
étant positionné à une certaine distance du premier axe de rotation (5), et/ou le
bord arrière (11) du safran de gouvernail (3) dans la position neutre du safran de
gouvernail (3) étant positionné à une certaine distance du troisième axe de rotation
(9).