Rudder

A rudder assembly for a boat in which a rapid pivotal displacement of the tiller from a first position to a second position displaces the rudder into either a raised or a lowered position, and which comprises a biased locking means for releasably retaining said tiller in a first position.

FIELD OF THE INVENTION 
The present invention relates to a rudder assembly for a boat, in 
particular light sailing or motor boats, and in particular to such an 
assembly provided with means for raising and lowering the rudder out of 
and into a steering position. 
BACKGROUND OF THE INVENTION 
Rudder assemblies for boats must clearly be provided with means whereby the 
rudder can be readily raised or lowered out of or into its steering 
position. Thus, when the boat is being pushed into the water the rudder 
must clearly be raised, and in the water the rudder should be readily 
lowered into a steering position. Similarly, when approaching the shore it 
must be possible readily to raise the rudder and this possibility must 
also be readily available when the boat is in the vicinity of reefs or 
other objects which project from or are close to the water line. 
Various proposals have been made and many have been put into practice for 
displacing the rudder into and out of its steering position, but these are 
all characterized by being relatively time consuming in operation with the 
consequent danger that, in an emergency such as, for example, when the 
boat is approaching a reef or other obstacle, it is not possible to 
quickly raise the rudder out of its exposed lowered position and, in 
consequence, the rudder and even the boat may be damaged. These problems 
arise even more acutely with catamarans, wherein each hull is provided 
with a separate rudder assembly and speed of operation in raising and 
lowering the rudder is even more essential. 
It is an object of the present invention to provide a new and improved 
rudder assembly for a boat, wherein the above-referred-to disadvantages 
are significantly reduced. 
BRIEF SUMMARY OF THE INVENTION 
According to the present invention there is provided a rudder assembly for 
a boat comprising: 
a rudder support bracket for mounting on the boat so as to be pivotable 
about a rudder steering axis; 
a rudder coupled to said bracket so as to be pivotable with respect thereto 
about a first axis substantially normal to said steering axis and to a 
longitudinal axis of the boat; 
a tiller coupled at a first end thereof to said bracket so as to be 
pivotable with respect thereto about a second axis substantially parallel 
to said first axis; and 
a coupling rod coupled at a first end thereof to said tiller so as to be 
pivotable with respect thereto about a third axis adjacent and parallel to 
said second axis, and coupled at a second and opposite end thereof to said 
rudder so as to be pivotable with respect thereto about a fourth axis 
adjacent and parallel to said first axis; 
the arrangement being such that a rapid pivotal displacement of the tiller 
from a first position to a second position displaces the coupling rod from 
a first condition wherein said first, third and fourth axes are 
non-aligned through a dead center condition wherein said axes are aligned 
and into either of two maximally displaced conditions wherein said axes 
are non-aligned and said rudder is displaced into either a raised or a 
lowered position. 
Preferably, there is provided a spring biased locking means mounted on said 
bracket for releasably retaining said tiller in a first position. 
With such a rudder assembly in accordance with the invention a simple, 
rapid displacement of the tiller from its locked (preferably lowered) 
position is effective in displacing the rudder either into its lowered 
steering position or its raised position. As indicated, the displacement 
of the tiller is accompanied by a corresponding displacement of the 
coupling rod through its dead center position and a corresponding pivotal 
displacement of the rudder. The initial momentum imparted to the rudder as 
a result of the initial rapid displacement of the tiller enables it to 
move under its own inertia into the required final raised or lowered 
position. It will be appreciated, in this connection, that when the rudder 
is to be lowered into its steering position, the effects of inertia in 
completing its displacement into the lowered steering position are 
supplemented by the weight of the rudder itself. 
Preferably, the spring biased locking means is so designed that any 
untoward encounter of the lowered rudder with an object such as a rock, a 
large fish, or the like results in the release of the locking mechanism 
and thereby allows for the movement of the rudder under the force of 
impact, thereby minimizing damage to the rudder as a result of the impact.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
As shown in the drawings, the rudder assembly comprises a C-shaped, 
double-walled mounting bracket 1 (for clarity of understanding, one of the 
walls is shown removed) which is pivotally mounted on a pivotal axle 2 
journalled with respect to bearings 3a and 3b which are, in their turn, 
mounted on a hull 4 of a boat (not otherwise shown). The bracket 1 is 
therefore pivotable with respect to the hull 4 about an axis hereinafter 
referred to as the "rudder steering axis". 
A rudder 5 has an innermost end thereof located between the walls of the 
bracket 1 and is pivotally mounted with respect thereto about an axle 6 
(constituting a first pivotal axis) directed normally with respect to the 
rudder steering axis. 
A tiller 7 is coupled at an end 7a thereof to the bracket 1 about an axle 8 
constituting a second pivotal axis substantially parallel to the first 
pivotal axis. 
A coupling rod 9 is pivotally coupled at a first end thereof to the end 7a 
of the tiller 7 about an axle 10 constituting a third pivotal axis located 
adjacent to and parallel to the second pivotal axis. The coupling rod 9 is 
pivotally coupled at an opposite end thereof to the rudder 5 about an axle 
11 constituting a fourth pivotal axis located adjacent and parallel to the 
first pivotal axis. 
A locking bar 12 (seen clearly in FIG. 5 of the drawings) constituting 
locking means is formed at an upper end thereof with a locking hook 13 
and, at a lower end thereof, with a crescent-shaped slot 14. The locking 
bar 12 is pivotally mounted with respect to the bracket 1 about a pivotal 
axis 15. An abutment pin 16 integral with the bracket 1 projects into the 
slot 14 in which is also located a biasing spring 17 tending to bias the 
locking bar 12 in an anti-clockwise direction with respect to the axle 15. 
The operation of the assembly in lowering and raising the rudder will now 
be described. 
As seen in FIG. 1 of the drawings, the rudder 5 is in a raised condition 
with the tiller 7 locked by means of the locking bar 12 (the locking nose 
13 engages the uppermost end of the coupling bar 9) in a lowered position. 
If now it is desired to lower the rudder 5 into the steering position (as 
shown in FIG. 3 of the drawings) the free end of the tiller 7 is rapidly 
raised to the position shown in FIG. 2, causing the clockwise displacement 
of the locking bar 12 against the spring biassing and thereby releasing 
the tiller 7 from its locked position and, at the same time, resulting in 
the displacement of the coupling rod 9 and the consequent pivotal downward 
displacement of the rudder 5 about its pivotal axle 6. The rapid raising 
of the tiller 7 imparts to the rudder 5 sufficient momentum in its 
downward pivotal displacement so that, when the axles 6, 10 and 11 pass 
through their dead center aligned position, the rudder 5 will nevertheless 
continue under its own inertia in its downward displacement into its 
lowered position, whereupon the tiller 7 can then be lowered into the 
position shown in FIG. 3 and locked in this position by engagement with 
the locking bar 12. 
The pivotal movement of the rudder 5 into its lowered position is also 
assisted by virtue of the weight of the rudder 5 itself. 
When it is desired to raise the rudder 5 the tiller 7 is again rapidly 
raised, thereby releasing it from its locking engagement with the locking 
bar 12 and, as a result of the consequent displacement of the coupling rod 
9, the rudder 5 is pivotally displaced about its axle 6 in a clockwise 
direction. The pivotal momentum induced in the rudder 5 as a result of 
this rapid displacement of the tiller 7 is such as to enable it to 
continue under its own inertia into a fully raised position, despite the 
fact that the coupling rod 9 passes through a dead center position wherein 
the axles 6, 11 and 10 are substantially aligned. In this case, too, once 
the rudder 5 will have reached its fully raised position as seen in FIG. 1 
of the drawings, the tiller 7, which will then be in the raised position 
shown in broken lines in FIG. 1, can be returned to its full line position 
shown in FIG. 1, whereupon it is engaged and releasably retained by the 
locking bar 12. As has been clearly stressed, the effectiveness of the 
assembly in ensuring the rapid raising or lowering of the rudder 5 is 
dependent on the initial rapid raising of the tiller 7, thereby ensuring 
that the pivotal momentum imparted to the rudder 5 is sufficient for the 
rudder 5 to continue its displacement into the required position, despite 
the fact that the coupling rod 9 will have passed through its dead center 
position. 
Thus, as seen in FIG. 4 of the drawings, where the rudder 5 is initially in 
its raised position as shown in broken lines, the coupling rod 9 is in the 
position also shown in broken lines. If now the tiller 7 is raised slowly, 
the rudder 5 will be displaced into the position shown in full lines, as 
will be coupling rod 9. In this case, however, the momentum imparted to 
the rudder 5 will be insufficient to ensure that the rudder 5 continues 
its movement into the fully lowered position after the axes are fully 
aligned and the coupling rod 9 is in the dead center position, and the 
rudder 5 will remain in the full line position shown in FIG. 4. Upon 
return of the tiller 7 to its lowered position in which it becomes locked 
by the locking bar 12, the rudder 5 will return to its broken line 
position. A similar situation occurs when the rudder 5 is initially in its 
lowered position and the slow raising of the tiller 7 is insufficient to 
impart to the rudder 5 sufficient momentum to ensure its effective 
lowering into the steering position. 
With the rudder 5 in the lowered steering position, any accidental 
encounter of the rudder 5 with an obstacle such as, for example, a rock or 
a large fish will result in the releasing displacement of the locking bar 
12 and the consequent freeing for pivotal displacement of the rudder 5, 
thereby minimizing damage to the rudder by such an encounter. It will be 
appreciated that the spring biasing effected by the spring 17 is suitably 
chosen so as to ensure that, on the one hand, the tiller 7 is effectively 
locked against accidental release but, on the other hand, when necessary 
the tiller 7 can be rapidly released from locking, as well as upon 
accidental encounter of the rudder 5 with an obstacle. 
Reference is now made to FIGS. 6 and 7 of the drawings wherein a modified 
form of locking means is seen, in which those components which are similar 
to those of the previous embodiment are designated with similar reference 
numerals. 
A locking member 20 has formed at an upper end thereof a locking recess 21 
and is pivotally mounted on bracket 1 about a pivotal axis 22. An 
adjustment screw 23 is screwed to the locking member 20 via a hole 24 in a 
wall 26 of the bracket 1, the hole 24 having a larger diameter than that 
of the adjustment screw 23 and a resilient abutting member 27 is attached 
to locking member 25, biassing it in an anti-clockwise direction with 
respect to the axis 22. The first end of the coupling rod 9' has attached 
thereto a roller 28 free to rotate about the axis 10', the purpose of 
which is to assist in the engaging of said first end with the locking 
recess 21. 
The engaging and disengaging of the coupling rod 9 with the locking member 
20 is performed in a manner similar to that already explained in 
connection with the previous embodiment, the main difference being that 
according to the present modification, the force required for locking and 
unlocking is adjustable and may be pre-set according to the weight of the 
rudder and according to individual requirements simply by varying the 
position of the adjustment screw 23, thus varying the maximum degree of 
the angular displacement of the locking member. 
With a rudder assembly in accordance with the present invention, the 
lowering and raising of the rudder 5 can be simply and effectively 
effected by a simple, instantaneous raising of the tiller 7. This is in 
contradistinction to the time-consuming methods employed with known rudder 
assemblies. Furthermore, the fact that one and the same tiller 7 can be 
employed both for steering and for raising and lowering the rudder 5 is, 
of course, a distinct advantage.