Note: Descriptions are shown in the official language in which they were submitted.
CA 02333831 2001-02-05
PERSONAL WATERCRAFT AND
OFF-POWER STEERING SYSTEM FOR
A PERSONAL WATERCRAFT
The present application claims priority to U.S. Provisional Appln. of Simard,
Ser. No. 60/180,223, filed February 4, 2000, the entirety of which is hereby
incorporated into the present application by reference.
Field of the Invention
The present invention relates generally to a steering control mechanism for a
personal watercraft ("PWC"). More specifically, the invention concerns a
control
system that assists in steering a PWC when the jet pump pressure falls below a
predetermined threshold.
2. Description of Related Art
Typically, PWCs are propelled by a jet propulsion system that directs a flow
of water through a nozzle (or venturi) at the rear of the craft. The nozzle is
mounted
on the rear of the craft and pivots such that the flow of water may be
directed between
the port and starboard sides within a predetermined range of motion. The
direction of
the nozzle is controlled from the helm of the PWC, which is controlled by the
PWC
user. For example, when the user chooses to make a starboard-side turn, he
turns the
helm to clockwise. This causes the nozzle to be directed to the starboard side
of the
PWC so that the flow of water will effect a starboard turn. In the
conventional PWC,
the flow of water from the nozzle is primarily used to turn the watercraft.
At low speeds (i.e., when the user stops applying the throttle), the motor
speed
(measured in revolutions per minute or RPMs) drops, slowing or stopping the
flow of
water through the nozzle at the rear of the watercraft and, therefore,
reducing the
water pressure in the nozzle. This is known as an "off throttle" situation.
Pump
pressure will also be reduced if the user stops the engine by pulling the
safety lanyard
or pressing the engine kill switch. The same thing would occur in cases of
engine
failure (i.e., no fuel, ignition problems, etc.) and jet pump failure (i.e.,
rotor or intake
jam, cavitation, etc.). These are known as "off power" situations. For
simplicity,
30142120V1
CA 02333831 2001-02-05
throughout this application, the teen "off power" will also include "off
throttle"
situations, since both situations have the same effect on pump pressure.
Since the jet flow of water causes the vehicle to turn, when the flow is
slowed
or stopped, steering becomes less effective. As a result, a need has developed
to
improve the steerability of PWCs under circumstances where the pump pressure
has
decreased below a predetermined threshold.
One example of a prior art system is shown in U.S. Patent 3,159,134 to
Winnen, which provides a system where vertical flaps are positioned at the
rear of the
watercraft on either side of the hull. In this system, when travelling at slow
speeds,
where the jet flow through the propulsion system provides minimal steering for
the
watercraft, the side flaps pivot with a flap bar into the water flow to
improve steering
control.
A system similar to Winnen is schematically represented by Fig. 25, which
shows a watercraft 1100 having a helm 1114. Flaps 1116x, 1116b are attached to
the
sides of the hull via flap bar 1128x, 1128b at a front edge. Two telescoping
linking
elements 1150x, 1150b are attached to arms 1151a and 1151b, respectively, at
one end
and to the respective flap bars 1128x, 1128b at the other end, respectively.
Arms
1151x, 1151b, are attached to partially toothed gears l 152x, 1152b,
respectively.
Gear 1160 is positioned between gears 1152x, and 1152b to engage them. Gear
1160
is itself operated, through linking element 1165 and steering vane 1170, by
helm
1114. Fig. 19 illustrates the operation of the flaps when the watereraft is
turning to
the right, or starboard, direction.
Because the gears 1152x, 1152b are only partially toothed, when attempting a
starboard turn, only gear 1152b will be engaged by gear 1160. Therefore, the
left flap
1116a does not move but, rather, stays in a parallel position to the outer
surface of the
hull of the PWC 1100. Thus, in this configuration, the right flap 1116b is the
only
flap in an operating position to assist in the steering of the watercraft
1100.
While the steering system of Winnen, represented in Fig. 25, provides
improved steering control, the system suffers from certain deficiencies.
First, steering
is difficult. When the flap bars 1128 are located at the front portion of the
flaps 1116
(as shown), the user must expend considerable effort to force the flaps 1116x,
1116b
2
30142120V1
CA 02333831 2001-02-05
out into the flow of water. Second, the force needed to force flaps 1116a,
1116b into
the water stream causes considerable stress to be applied to the internal
steering
cabling system that may cause the cabling system to weaken to the point of
failure.
Third, only one flap 1116b is used at any given moment to assist in low speed
steering. Thus, the steering system shown in Fig. 19 is difficult to use,
applies
unacceptable stresses to the internal steering system, and relies on only half
of the
steering flaps to effectuate a low speed turn.
Such a system could be modified to use simpler telescoping linking elements
to attach the steering vane 1170 to flaps 1116, instead of the more complex
gear
arrangement. Unfortunately, the sliding nature of the telescoping linking
elements
makes these structures susceptible to seizing up in salt water.
For at least these reasons, a need has developed for an off power steering
system that is more effective in steering a PWC when the pump pressure has
fallen
below a predetermined threshold.
SUMMARY OF THE INVENTION
A PWC according to this invention has an improved system comprising at
least one flap or rudder placed at a side of the hull. This invention relates
to the
design and operation of generally vertical rudders positioned on the port and
starboard
sides of the PWC hull that assist in steering the PWC when the pump pressure
falls
below the predetermined threshold. In addition, the rudders can be vertically
adjustable to provide even greater assistance in steering control when the
pump
pressure falls below the predetermined threshold.
Therefore, one aspect of embodiments of this invention provides an off power
steering system in which the rudders and linking elements assist the driver in
steering
a PWC in off power situations without causing undue stress on the driver or
the helm
control steering mechanisms.
Another aspect of the present invention provides a PWC with simplified
linking elements that do not seize up in salt water, and are less complex than
those
known in the prior art.
30142120V1
CA 02333831 2001-02-05
An additional aspect of the present invention provides an off power steering
mechanism that automatically raises and lowers vertical rudders according to
the
water flow pressure within the venturi or flow nozzle.
A further aspect of the present invention can make off power steering more
efficient by using both rudders simultaneously and in tandem to assist in
steering.
Embodiments of the present invention also provide an improved mdder that
can be used with an off power steering system.
An additional embodiment of the present invention provides an off power
steering mechanism kit to retrofit a PWC that was not manufactured with such a
mechanism.
These and other aspects of the present invention will become apparent to those
skilled in the art upon reading the following disclosure. The present
invention
preferably provides a rudder system wherein a rudder is positioned near the
stern and
on each side of the hull of a PWC. The preferred embodiment utilizes a pair of
1 S vertically movable rudders operating in tandem during steering.
The invention can provide a steering system that is simpler to build and
easier
to steer. The system can automatically lower the vertical rudders when
off=power
steering is necessary and can automatically raise the vertical rudders when
off power
steering is not needed.
The rudders according to this invention are spaced a predetermined distance
from the hull and pivot from a position inwardly from an edge of the rudder to
enable
water to flow on an inside surface and an outside surface. Other embodiments
of the
invention are described below.
It is contemplated that a number of equivalent structures may be used to
provide the system and functionality described herein. It would be readily
apparent to
one of ordinary skill in the art to modify this invention, especially in view
of other
sources of information, to arrive at such equivalent stmctures.
4
30142120V1
CA 02333831 2001-02-05
BRIEF DESCRIPTION OF THE DRAWINGS
An understanding of the various embodiments of the invention may be gained
by virtue of the following figures, of which like elements in various figures
will have
common reference numbers, and wherein:
Figure 1 illustrates a top view in partial section of a first embodiment of
the
present invention with the flaps in the inactive position;
Figure 2 illustrates the first embodiment of the present invention with the
starboard flap in an operable position;
Figure 3 is a perspective view of the starboard flap in an operable position;
Figure 4 illustrates a top schematic view of a second embodiment of the
present invention;
Figure S illustrates a back view in partial section of a third embodiment of
the
present mvent>on;
Figure 6 illustrates a side view in partial section of the third embodiment of
1 S the present invention;
Figure 7 illustrates the top view in partial section of the starboard rudder
of a
third embodiment of the present invention;
Figure 8 illustrates a back view in partial section of a fourth embodiment of
the present invention;
Figure 9 illustrates a side view in partial section of the fourth embodiment
of
the present invention;
Figure 10 illustrates a back view in partial section of a fifth embodiment of
the
present invention;
Figure 11 illustrates a schematic top view in partial section of a sixth
embodiment of the present invention;
5
30142120V 1
CA 02333831 2001-02-05
Figure 12 illustrates a back view in partial section of the sixth embodiment
of
the present invention;
Figure 13 illustrates a back view in partial section of a variation of the
sixth
embodiment of the present invention with a modified rudder;
Figures 14a through 14c illustrate various partial perspective views of the
rudder according to the sixth embodiment of the present invention;
Figures 15a through 15c illustrate a seventh embodiment of the present
invention from a top view;
Figure 16 illustrates the seventh embodiment of the present invention from a
partial side view;
Figure 17 shows a chart comparing the various distances necessary to stop and
turn a PWC operating with and without flaps;
Figure 18 is a top view of the port half of a PWC with the deck removed and a
portion of the tunnel cut away, the view illustrating an eight embodiment of
the
invention;
Figure 19 is a partial sectional view taken along line 21-21 in Figure 18;
Figure 20 is an elevated view of a piston/bracket unit used in the eighth
embodiment of the invention;
Figure 21 is a cross-sectional view taken along line A-A of Figure 22;
Figure 22 is a perspective view of a rudder used in the eighth embodiment of
the invention;
Figure 23 is a partial cross-sectional view showing the interconnection
between the rudder and the rod through the opening in the hull wall in the
eighth
embodiment;
Figure 24 is a cross-sectional view of a T-connector used in the eighth
embodiment of the invention; and
6
30142120V1
CA 02333831 2001-02-05
Figure 25 shows a prior art system using gear operated flaps.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The invention is described with reference to a PWC for purposes of
illustration. However, it is to be understood that the steering and stopping
systems
described herein can be utilized in any watercraft, particularly those crafts
that are
powered by a jet propulsion system.
The first embodiment of the invention will be understood with reference to
Figs. 1-3. In Fig. 1, a top view of the stern of the PWC 10 is shown. The hull
38 is
only shown generally in a schematic outline to highlight the important
structures of
the invention. In some of the following figures, a flap or rudder system of
only one
side of a PWC 10 is shown for simplicity. It is to be understood that the
system
described for one flap is equally applicable for a flap on the other side of
the craft.
The first embodiment of the invention is referred to as a "flap" system
because
the flaps are hinged at an edge and thus only one side of the flap deflects
water to
assist in steering. The prior art system to Winnen described above is an
example of a
flap system. The other embodiments discussed below are referred to as "rudder"
systems because the rudder pivots at a point spaced a certain distance inward
from the
edge of the rudder. In addition, the rudders are positioned away from the
surface of
the hull to enable water to flow on both the inside surface and/or the outside
surface
of the rudder to assist in steering the PWC. The advantages of the rudder
system are
described in more detail below.
It is understood that a corresponding flap or rudder system is preferably
placed
on each side of the hull 38 shown in Fig. 1. Although the preferred two flap
or rudder
system is shown in the embodiments disclosed herein, a single flap or rudder
can be
used if desired. It is also preferable to have the flap or rudder system as
far as
possible from the center of gravity of the PWC (i.e., near the transom) while
still
being located in the high pressure relative flow generated by travel of the
hull through
the water in order to have the greatest possible moment arm for the forces
applied by
the flap or rudder. This will provide more efficient steering. Accordingly,
where
7
30142120V1
CA 02333831 2001-02-05
specific details regarding the off power steering structure are provided for
only one
side, the details are applicable to a corresponding structure on the opposite
side.
Additionally, while the flap or rudder is shown as being attached to a side of
the hull,
it is also possible to attach a flap or rudder in accordance with this
invention to the
stern.
The flap system according to the first embodiment of the present invention
provides a steering system in which the flaps 216a, 216b each rotate around
two
different axes instead of just one. The object of this embodiment is to
position the
flaps deeper in the water to increase their steering efficiency while
minimizing the
contact with the water to minimize drag when the flaps are not required for
steering.
The flap systems 40a, 40b comprise the flaps 216a, 216b and double-ended
ball joints 43a, 43b that attach the flaps 216a, 216b to the hull 38. Flap
system 40a is
on the port side, and flap system 40b is on the starboard side. The double-
ended ball
joints 43a, 43b comprise rods 42a, 42b connected 48a, 48b to the hull 38. Any
known
means may be used to secure the rods 42a, 42b to the hull 38, such as a nut
and bolt
52a, 52b. The ball joint rods 42a, 42b are linked by connectors 46a, 46b to
ears 44a,
44b. The ears 44a, 44b are connected to flaps 216a, 216b, respectively, at a
top
portion thereof.
As shown in Fig. 1, flap 216b has a hinged connection SOb connected to
another hinged connection element 56b. The connection 56b pivots around the
axis
shown as B-B. This is the first of two axes around which the flap 216b
rotates. The
second axis of rotation for the flap 216b is provided by hinge SOb. A front
flange,
which is shown as 62b in Fig. 3 for the starboard side flap system of this
hinge SOb, is
mounted on a pivot 56b attached (by a screw for example) into the hull 38. The
pivot
56b allows the vertical hinge SOb to rotate around a horizontal axis.
The flap system 40a is connected via connecting element 30a to a telescoping
linking element 20. The inner structure of the telescoping linking element is
referred
to as 20a. The telescoping structure 20 is connected to a nozzle 18 via a
pivoting
element 24. The pivoting element 24 can be any structure that enables the
linking
structures to connect to the nozzle 18 and permits the nozzle 18 to pivot to
manipulate
30142120V 1
CA 02333831 2001-02-05
the flaps 216a, 216b. Nozzle 18 revolves around pivotal point 26 to steer the
PWC 10
at high speeds (or with the throttle in the on position).
The venturi 32 directs the flow of water from the jet propulsion system 34 and
causes the water to increase in speed as it flows through the venturi 32 to
the nozzle
18. The diameter of the venturi 32 decreases to force the water to travel
faster
through the venturi opening. A stabilizer or sponson 12a, 12b attached to the
outer
surface of the hull on the port side directs the flow of water and assists in
stabilizing
the PWC 10. While Fig. 2 illustrates the venturi 32 and nozzle 18 as separate
elements pivotally connected, it is noted that variations of the
venturi/nozzle structure
are considered to be within the scope of the present invention. Thus various
water
propulsion structures may be used to perform the functions of the
venturi/nozzle
combination, namely propelling water at a high rate of speed along with
providing
steering capabilities.
Figure 3 illustrates the starboard flap 216b in an operational position. To
move flap 216b into this position, the user turns the helm (not shown) to the
right or
in the starboard direction. The nozzle 18 pivots around pivoting point 26 to
steer the
watercraft to the starboard direction. The pivotal connection 24 causes
linking
element 22 and telescoping insert 22a to force the flap 216b out into the flow
of water
(shown by the intermittent arrows). In this position, the flap 216b is
connected to the
hull by element 44b, which is attached to rod 42b by stmcture 46b. Rod 42b is
connected to the hull by ball joint 52b. It is preferred that the rod 42b is
stiff, so that
it does not allow the connecting element 44b to pivot with respect to the rod
42b.
However, it is contemplated that structures providing flexibility at this
point may also
be used.
The rod 42b connects through connector 48b to the hull 38 via bolt and nut
arrangement 52b or some equivalent structure. The connecting element 44b,
structure
46b and rod 42b firmly hold the top portion 61b of flap 216b in place and
prevent it
from swinging out vertically into the flow of water. While one particular
arrangement
is illustrated, other equivalent structures may also be provided to support
the top
portion 61b of the flap 216b.
9
30142120V1
CA 02333831 2001-02-05
When the helm 14 moves, it causes the flap 216b to assist in turning the PWC
into the starboard direction. In operation, the flap 216b pivots out into the
water
on hinge SOb in a substantially vertical direction and also pivots on bolt 54b
around
the axis shown by line B-B. Similarly, when the flap 216a is forced outwardly
5 because of the pushing force coming from the telescopic linking element 20,
the
double ended ball joint 43a and ear 44a simultaneously push back the top of
the flap
216a. By the effect of the force given by the ear 44a, the rear of the flap
216a is
forced to go down deeper into the water.
In this embodiment, because telescoping linking arms 20, 22 are used, the flap
10 216a that is opposite the flap 216b being moved into the operative position
remains
parallel to the side of the hull 38 and the PWC in an inactive position. Thus,
only one
rudder at a time provides steering assistance.
Figure 3 is a perspective view of the flap 216b in the operative position. The
flap supporting structure 44b, 42b, 46b and 48b secures the top portion of the
flap
216b to prevent it from swinging outwardly or pivoting downwardly into the
flow of
water. As can be seen from Fig. 3, the lower portion 60b of the flap 216b
pivots out
further into the flow of water than the top portion illustrated by feature
61b. This
causes the water to flow more easily over the top portion 61b of flap 216b, as
illustrated by the intermittent arrows. Thus, in the operative position, flap
216b pivots
around both the axis of hinge SOb, which axis is shown by intermittent line C-
C, and
the axis of bolt 54b, which is connected to hinge SOb via a connecting
structure shown
as 62b. The axis of rotation shown by the intermittent line B-B shows flap
216b
rotated into an optimal position in the water coming from stabilizer 12b.
While the first embodiment described above uses flaps in which water will
flow on only one side, the dual pivoting motion of the flap about two
different axes
makes it more efficient and effective than a system having a single pivoting
motion,
such as Wennen.
Fig. 4 illustrates the second embodiment of the present invention. This
embodiment is directed to addressing the problems of (1) the lack of
efficiency in
using only one rudder at a time to steer, and (2) the stresses transferred to
the steering
components.
30142120V1
CA 02333831 2001-02-05
According to an embodiment of the invention as shown in Fig. 4, the PWC 10
has a helm 14. Stabilizers or sponsons 12a, 12b are attached at the side rear
of the
hull 38 and rudders 316a, 316b are connected to the hull 38 via hinges 68a,
68b. The
hinges 68a, 68b connect the rudders 316a, 316b to the hull 38 a certain
distance from
the forward ends of the rudders 316a, 316b.
A nozzle 18 pivots around a pivoting connection 26. This pivoting connection
26 may be of any kind that is well known to those of ordinary skill in the
art. The
nozzle 18 is pivotally connected 24 to linking elements 66a, 66b. In the
preferred
embodiment, the linking elements 66a, 66b are not telescoping bvt are made
from a
single rigid structure. In this manner, they are easier to build and are more
reliable
than more complicated, telescoping structures known in the prior art. By using
non-
telescoping linking elements 66a, 66b, both rudders 316a, 316b are
simultaneously
moved with the rotation of the nozzle 18.
As shown in Fig. 4, when the PWC 10 is turned to the starboard direction via
the helm 14, the nozzle 18 directs water flow from the jet propulsion system
toward
the starboard side of the PWC 10, which causes it to turn. According to the
present
invention, when the nozzle 18 is in this position, the port side rudder 316a
is pulled
inward toward the longitudinal axis of the PWC 10, shown by line A-A. Pulling
the
port side rudder 316a inward increases water pressure on the inside surface of
rudder
316a, which assists in steering PWC 10 in the starboard direction. In
addition, linking
element 66b extends rudder 316b out into the water flowing off of sponson 12b.
Since linking elements 66a, 66b, are pivotally connected 24 to a different
portion of
the nozzle 18, rudders 316a, 316b, have different turning angles. For a
starboard turn,
rudder 316b turns more than rudder 316a and creates a larger angle with
respect to the
axis A-A. Rudder 316a creates a high lift and a low drag, while rudder 316b
creates a
high drag and a high lift, both of which assist in steering the PWC to the
starboard
direction.
In addition, because hinged elements 68a, 68b are placed inward from the ends
67a, 67b of the rudders 316a, 316b, it is easier for the user to turn the
steering
mechanism at the helm 14 to manipulate the rudders 316a, 316b into the flow of
water
to assist in the off throttle steering. Thus, this system reduces the stress
both on the
steering mechanisms and on the user.
11
30142120V 1
CA 02333831 2001-02-05
Turning to Fig. 5, this figure illustrates the third embodiment of the present
invention. This embodiment is directed to addressing the some of the same
problems
as the second embodiment above. In addition, the third embodiment also
addresses
the problem of the drag on the rudders when they are in the lower position in
the
water. If the rudders are always in a down position, they tend to produce drag
in the
water and slow the PWC down when it is operating at high speeds.
As shown in Fig. 5, the rudder 416b includes a plurality of fins 94 positioned
to catch water when the rudder 416b is moved into an operative position. The
fins 94
are angled, preferably at 15 degrees, to draw flowing water that pulls the
rudder 416b
down further into the water. Alternately, the fins 94 may be disposed at any
angle to
effect a drawing of water, preferably between about 5 and 25 degrees, but
about 15
degrees is most preferred. In other words, when the fins 94 catch the water
flowing
off the stabilizer or sponson 12b and the bottom of the hull, this forces the
rudder
416b down further into the path of the flowing water to assist in steering PWC
10.
As shown in Fig. 5, the hull 38 of the PWC 10 is connected to the deck 70 and
a covering structure 72 covers the connecting point between the deck 70 and
the hull
38. Bolts 88a, 88b connect a U-shaped bracket structure 76 to hull 38 to
support
rudder 416b and enable it to move up and down. The bracket 76 also supports
the
hinged movement of rudder 416b around the axis shown as D-D. The starboard
linking element 66b is shown attached generally to rudder 416b. A spring 86
biases
the rudder 416b into a high inactive position out of the water. The bottom 96
of
rudder 416b is shown in its high position and, in phantom 97, in the lower
position.
Bushings 92 allow the rudder 416b to move up and down with less friction.
Preferably, a lubricant 82 is used for durability. The hinge structure
supported by the
bracket 76 enables the rudder 416b to both move up and down to a position in
or out
of the water and also to rotate around axis D-D.
Figure 6 is a side view of the third embodiment of the present invention. The
fins 94 are shown. It should be noted that any number of fins can be used,
including
just one fin, even though a plurality of fins 94 are illustrated. The linking
element 66b
is shown in phantom to illustrate where it connects to rudder 416b. A raised
nose 98
extends from the front edge and on both sides of the rudder 416b and directs
the flow
of water around the rudder 416b. The nose 98 redirects the water flowing over
the
12
30142120V 1
CA 02333831 2001-02-05
rudder 416b to prevent water from engaging the fins 94 when the rudder 416b is
in its
inactive position. The rudder 416b rotates around axis D-D when activated by
the
linking member 66b. A plurality of openings 96 are located in the areas in
between
the fins 94 in order to allow water to flow therethrough when rudder 416b is
in the
operative position. Water flows over rudder 416b after being directed from the
stabilizer 12b and the bottom of the hull.
When the rudder 416b opens to its operative position, water flows over the
nose 98 and flows over the fins 94. The force of the water on the fins 94
causes the
rudder 416b to move down and compresses the spring 86 to bring the rudder 416b
into its fully lowered position in the water. Because of the openings 96
integrated
between the fins 94, water applies pressure to the fins 94 to force the rudder
416b
down when the rudder 416b is used to steer to the starboard direction and
water flows
on the outside surface of the rudder 416b. The same is true when the rudder
416b
steers the PWC 10 to the port direction and water flows on the inside surface
of the
rudder 416b.
Figure 7 illustrates a top view of the various positions of rudder 416b (shown
in Fig. 6). As discussed earlier with respect to Fig. 5, the rudder 416b is
spaced away
from the hull 38 of the PWC 10. Spacing the rudder 416b away from the hull 38
in
addition to moving the pivotal location 74 of the rudder 416b away from the
edge of
the rudder 416b allows the rudder 416b to be used in steering the watercraft
either to
the port or the starboard direction. For example, rudder 416b can be moved
into the
position shown by 106. In this position, water flowing off of the stabilizer
12b will
flow over the fins 94 that pull the rudder 416b down into the water. As the
rudder
416b moves down into the water, more fins 94 will catch the water and thus
further
pull the rudder 416b into the water. The force of the water flowing over the
rudder
416b will cause the PWC 10 to steer towards the starboard direction. However,
if the
user wants to steer the PWC 10 towards the port side, the linking element 66b
will
pull the rudder 416b into the position shown by the intermittent outline 108.
In this
position, water flowing off the stabilizer 12b and the bottom of the hull will
flow
across the inside surface of the rudder 416b.
The fins 94 are preferably angled at approximately 15° to the
horizontal.
Other angles may be used also (preferably between 5 and 25 degrees), as long
as the
13
3014212~V I
CA 02333831 2001-02-05
fins 94 operate to pull the rudder 416b into the water against the bias of
spring 86 so
that the rudder operates to assist in the off power steering of the PWC 10.
Figure 8 illustrates the fourth embodiment of the present invention. According
to this embodiment, the rudder S 16b is attached to the hull 38 via bolts 88a,
88b.
Other means of attachment may also be employed and will be apparent to those
of
ordinary skill in the art. A spring 86 biases the rudder S 16b in an upward
position
124. In this manner, the rudder S 16b will normally be in its upward position
124.
However, once the rudder S 16b rotates out into the flow of water, an
articulated,
rotatable mini flap 112 positioned on the rudder S 16b will assist in pulling
the rudder
S 16b into the water. When the rudder rotates, the mini flap 112 rotates
around axis F-
F as shown in Fig. 9.
The water flowing over mini flap 112 as the rudder Sl6b is in its operable
position causes the mini flap 112 to rotate around axis F-F. A slider 113
attaches
element 114, 122 to the top of the mini flap 112 and forces the top of the
mini flap
1 S 112 to rotate inward when the rudder S 16b is opened into an operable
position in the
flow of water. Rotating the mini flap 112 to a certain position in connection
with
water flowing over the mini flap 112 forces the rudder 516b down against the
bias of
spring 86 and thus pulls the rudder S 16b down into the water. In this
operative
position, the rudder S 16b will be more effective in helping to direct and
steer the
PWC 10 in off power conditions.
Figure 10 shows a fifth embodiment of the present invention and is similar to
other embodiments except that the spring 86 biases the rudder 616b down into
the
water rather than up, as was discussed previously. The mdder is labeled in
Fig. 10 as
616b, but in this and other embodiments, the various illustrations of the
rudder
2S systems are interchangeable. For example, the basic rudders 316a, 316b,
shown in
Fig. 4, or the variable surface rudders 716a, 716b, shown in Figs. 14a-14c,
may be
interchangeably used with the various embodiments of the invention.
In the fifth embodiment of the invention, structural elements 130 shown in
Fig. 10 connect the rudder 616b to a rod 129 and operate to move the rudder
616b up
or down, also referred to as vertical movement. It is to be understood that
any
reference to movement in a relative up or down position, especially with
respect to the
14
30142120V1
CA 02333831 2001-02-05
surface of the water, is considered herein to be vertical movement even though
it may
be at an angle to true vertical.
The rudder 616b may be positioned high 132 or low and in water 128. The
structural elements 130 enable the rudder 616b to pivot around an axis D-D and
to
move up and down into the upper and lower positions as previously discussed.
This
embodiment is useful because the rudder 616b can be positioned or biased in
the
water but can be moved out of the water if the watercraft strikes a submerged
object
or is operating at high speeds, which can cause the hull to ride higher in the
water.
The rudder configuration of Fig. 10 is preferably used with the clutch system
disclosed below with reference to Figs. lSa-15c and 16.
Figure 11 shows the sixth embodiment of the present invention. As shown in
Fig. 11, water lines 136a and 136b are connected to holes 135a, 135b within
the
venturi 32. The water lines 136a, 136b respectively extend from holes 135a,
135b in
the venturi 32 through the linking elements 66a, 66b and out near the rudders
616a,
616b. The rudders 616a, 616b are connected to the hull via hinged elements
140a,
140b and the linking elements 66a, 66b connect the nozzle 18 to rudders 616a,
616b
via hinged elements 30a, 30b. The rudders 616a, 616b, are preferably angled
inwardly, as shown in Figure 1 l, to provide additional deceleration when they
are in a
lowered operable position. This angle can vary based on the vertical
positioning of
the rudders. The water lines 136a, 136b pass through linking elements 66a,
66b.
However, other means of connecting the water lines to the hinged portions
140a, 140b
are also contemplated, including passing the water lines 136a, 136b through
the hull
38 at the stern or attaching them on the outside surface of the hull.
This embodiment obviates the need for a clutch.
Figure 12 provides another view of the preferred embodiment of the present
invention. It shows a rear view of the starboard side rudder 616b. The
connection of
the linking element 66b to the rudder 616b is not shown in order to view the
hinge
structure of the invention. The hinged portion 140b comprises a rod 118, a
hinge 86,
and a water cylinder 146. The water line 136b exits from a hollow portion of
the
linking element 66b to a base portion 119 connecting an end of the water line
136b to
the water cylinder 146. A bracket 76 supports the above-mentioned elements
118, 86,
30142120V1
CA 02333831 2001-02-05
146 and enables the rudder 616b to be securely attached to the hull 38 while
being
able to both pivot and move vertically. The internal rod 118 has a distal end
115
positioned within the water cylinder 146. The spring 86 biases the rudder 16b
in a
lower position 142a, 142b. The rudder 616b slides up and down the water
cylinder
146 via projections 87 and 89 from the inner side of the rudder 616b. The
projections
87, 89 are attached to the rear surface of the rudder 616b. Each projection
87, 89 has
an opening complementary to the shape of the water cylinder 146. The
projection
openings enable the rudder 616b to slide up and down the outer surface of
cylinder
146.
From this configuration, it can be seen that when biased by the spring 86, the
rudder 616b is in a lower position such that water flowing off of the
stabilizer 12b will
flow across the rudder 616b if the rudder 616b is moved into the operable
position.
Thus, rudder 616b is capable of moving from a high position out of the water,
shown
by extended lines 144a and 144b, to a lower position 142a, 142b in the water
to assist
1 S in steering the PWC 10.
The amount of water pressure within the water cylinder 146 controls the high
or low position of the rudder 616b. The water pressure in the cylinder 146
depends
on the pressure of the water flowing through the venturi 32, as shown in Fig.
11.
When the throttle of the PWC is on, water is forced through the venturi 32 and
nozzle
18. The water pressure in the venturi 32 varies from a front position to a
more narrow
rear position. The holes 135a, 135b in the venturi 32 may be located at
various places
but preferably are located in the high pressure region. The high pressure
region is
where water flows more slowly and the diameter of the venturi 32 is larger.
Furthermore, as noted earlier, the venturi/nozzle configuration may vary
depending on the PWC. Accordingly, it is contemplated that water lines 135a,
135b
may communicate a water pressure from a location other than the venturi 32,
for
example from the nozzle 18 or perhaps a speed sensor or water collection port
located, for example, under the hull.
When the throttle is on and water pressure in the venturi 32 is high, water is
forced through the holes 135a, 135b into the water lines 136a, 136b. Water, as
shown
in Fig. 12, will flow through line 136b and begin to fill the water cylinder
146. The
16
30142120V1
CA 02333831 2001-02-05
water in the cylinder 146 forces the distal end 115 of the piston 118 upward.
The
piston 118 is connected to the rudder 616b, which in turn is connected to the
projections 87, 89. As the rudder 616b rises, projection 87 contacts and
compresses
the spring 86 against the spring bias. The rudder 616b moves into the higher
position
shown by 144a and 144b.
Water in the venturi 32 travels relatively slowly through the wider region 33
of the venturi 32. In this region, although the water travels more slowly, the
water
pressure is higher. Holes 135a, 135b are positioned preferably in this high
pressure
region 33 of the venturi 32. The venturi 32 narrows as it nears the exit
portion 35. As
the venturi 32 narrows to this region 35, water travels more quickly and the
water
pressure decreases. Water then is expelled out of the venturi 32 into the
nozzle 18
that pivots around pivotal point 26 in order to propel and steer the PWC 10.
In this embodiment, water hoses 136a, 136b are respectively attached to holes
135a, 135b. When water is flowing through the venturi 32 at a high rate of
speed and
the pressure in region 33 of the venturi 32 is high, water is forced out
through the
holes 135a, 135b into the respective water lines 136a, 136b. Linking elements
66a,
66b, as in previous embodiments, are connected via a pivotal point 24 to the
nozzle
18. Pivotal connecting elements 30a, 30b connect the linking elements 66a, 66b
to
the respective rudders 616a, 616b. On the starboard side, linking element 66b
connects via pivotal point 30b to the nozzle 18 and to the rudder 616b. The
linking
elements 66a, 66b may be hollow to allow the water lines 136a, 136b to be
inserted
therein and thus brought through the linking elements 66a, 66b near the
rudders 616x,
616b.
On the port side, water line 136a extends from the distal end of the linking
element 66a and connects to the hinged element 140a, which attaches a front
region of
rudder 616a to the hull 38 of the PWC 10. Similarly, on the starboard side,
the water
line 136b exits the distal end of linking element 66b and connects to the
hinged
element 140b, which connects a forward region of the starboard nidder 616b to
the
hull 38 of the PWC 10. (The hinged portions 140a, 140b will be shown in more
detail
below with reference to Fig. 12.) As shown in Fig. 11, as the water pressure
increases
in the venturi 32 in the high pressure region 33, water is forced into the
water lines
17
30142120V1
CA 02333831 2001-02-05
136a, 136b and passes to the hinged elements 140a, 140b to control the raising
and
lowering of rudders 616a, 616b.
Preferably, the rudders 616a, 616b will be forced into their upper position
when the PWC 10 has a jet pump pressure equivalent to the one obtained when
the
engine is operating at 4500 RPM or more under normal conditions. Below 4500
RPM, the flow of water through the venturi 32 is reduced, and the rudders
616a, 616b
will drop to their lower position, for example, approximately 2 inches deep in
the
water.
When the rudders 616a, 616b are not needed, i.e., when steering is available
through the jet propelled water traveling through the nozzle 18, the rudders
616a,
616b are positioned high in an inactive position and thus do not drag and slow
down
the PWC 10. However, when off power steering is necessary because water is not
flowing quickly through the venturi 32, the water pressure in lines 136a, 136b
is
reduced. The water in the water cylinder 146 is forced back through the water
lines
136a, 136b and out the holes 135a, 135b. The rudders 616b, 616a drop down into
position shown by 142a and 142b and thus come into contact with water flowing
off
of stabilizersl2a, 12b to allow the user to steer the PWC 10 at low speeds
where such
steering assistance is necessary.
According to the present invention, off power steering can be more efficiently
accomplished at low speeds in which the rudders 616a, 616b will automatically
drop
from a higher position to a lower position into the water once the water
pressure in the
venturi 32 reaches a certain level.
The preferred embodiment utilizes the pivotal arrangement of the rudders
shown in Fig. 4, which is more efficient because both rudders 316a, 316b are
used in
tandem. As is shown in Fig. 4, pivotal points 68a, 68b are not located at the
front
portions 67a, 67b of the rudders 316a, 316b. Because the pivotal points 68a,
68b are
positioned a certain distance from ends 67a, 67b, the force necessary to move
rudders
316a, 316b into the flow of water off of stabilizers 12a, 12b and the bottom
of the hull
is reduced. In addition to reducing the load on the rudder steering
components, the
water flow over the rudder is more balanced on each side of the hinge 68a,
68b.
18
30142120V1
CA 02333831 2001-02-05
As shown and discussed earlier, the nozzle 18 directs water flowing from the
jet propulsion system in certain directions in order to steer the PWC 10. In
the second
embodiment shown in Fig. 4, linking elements 66a, 66b are not telescoping as
was
shown in the previous embodiment but comprise a single rigid structure. The
pivotal
elements 24 connect linking elements 66a, 66b respectively to nozzle 18
allowing the
nozzle 18 to pivot when actuated by the steering mechanism at the helm 14. The
linking elements 66a, 66b are respectively connected, via pivotal points 30a,
30b, to
the rudders 316a, 316b.
In the second embodiment, when the user steers the watercraft, for example,
towards the right or starboard direction, the linking element 66a pulls the
rear portion
of rudder 316a inward towards the hull 38 and thus positions the rudder 316a
to allow
water to flow on the inner surface of n>dder 316a. The water flowing off of
stabilizer
12a thus passes over and is redirected by the inside surface of rudder 316a.
When
turning to the starboard side, pivotal element 24 causes the linking element
66b to
force rudder 316b out into the flow of water coming off of stabilizer 12b and
the
bottom of the hull.
In order to accomplish the result of using both rudders 316a and 316b in off
power steering, the rudders 316a, 316b are spaced farther apart from the hull
surface
38 than as shown in Fig. 1. As an example, the rudders 316a, 316b preferably
may be
spaced about 1.5 inches (about 38.1 mm) from the hull 38. This distance will
vary
depending on the components used and other factors known to those of skill in
the art.
For example, the distance may be selected from within a range between about
0.5 and
2 inches (about 38.1- 50.8 mm) from the hull. However, any suitable range may
be
selected based on the configurations and dimensions of the hull.
Both rudders 316a, 316b participate in the off power steering of the PWC 10.
In addition, the linking elements 66a, 66b do not need to be telescoping and
thus do
not have the susceptibility of seizing up or ceasing to operate in the
telescoping
fashion when used in salt water. Furthermore, single-structure linking
elements 66a,
66b are more cost effective and easier to maintain than their telescoping
counterparts.
In addition, the embodiment shown in Fig. 4 is easier for the user of the PWC
10 to
steer because the pivotal point of rudders 316a, 316b is moved a certain
distance from
the ends 67a, 67b of rudders 316a, 316b. In this manner, since the fulcrum of
the
19
30142120V 1
CA 02333831 2001-02-05
pivoting point of rudders 316x, 316b is moved into a position offset from the
edge of
the rudder, it is much easier for the driver of the PWC 10 to steer. The
linking
elements 66a, 66b operate on the rear edges of rudders 316a, 316b malting it
easier for
these rudders 316a, 316b to be forced out into the flow of water off of
stabilizers 12a,
12b.
The other embodiments also address these problems discussed above, namely
the lack of efficiency of the hinged rudder system, the strain of the vertical
rudder
system on the steering components, the drag of the rudders or rudders when
they are
in the lower position, and the negative aspects of the combined effect of the
nozzle
and rudders in a steering operation.
While Fig. 4 and Fig. 11 show the linking elements 66a, 66b and water lines
136a, 136b on the outside of the hull, other configurations are also
contemplated. A
double wall of fiberglass built inside the hull 38 near the stern portion may
also be
used to pass both the linking elements 66a, 66b and the water lines 136a, 136b
to the
rudders 616a, 616b. In this case, the linking elements 66a, 66b and water
lines 136a,
136b would be out of sight from the rear of the PWC 10. Bushings would likely
be
used in the sidewalk where the linkages 66a, 66b come through the hull 38.
Other
configurations and structures for connecting the water lines 136a, 136b and
linking
elements 66a, 66b to the rudders 616a, 616b also will be recognized by those
skilled
in the art. For example, a tubular cover can be provided over the linking
elements and
water lines.
Figure 13 illustrates a variation of the sixth embodiment of the present
invention. Fig. 13 shows the portside rudder 716a. The rudder 716a has a
modified
structure on its surface, shown generally at 151. The special structure of the
rudder
716a will be described below with respect to Figs. 14a-14c. As shown in Fig.
13,
piston 146 is connected to the rudder 716a using spring pins 147 at both ends
of the
rudder 716a. The piston 146 has a head portion 148 that is encased within a
water
cylinder 149. An opening 153 in the water cylinder 149 provides a fluid
connection
to the water line 136a which, as discussed earlier, is connected to an opening
135a in
the venturi 32.
30142120V1
CA 02333831 2001-02-05
When the water pressure increases in the venturi 32, water flows in the water
line 136a, through the opening 153 and into the water cylinder 149. Water is
trapped
within the piston region below the head 148 via a plastic O-ring 150 and the
head 148
of the water cylinder 149. Water flowing into the cylinder 149 causes the
piston 146
to rise and which thus lifts the rudder 716a up and out of the water.
As in earlier embodiments, a biasing spring 86 biases the rudder 716a in the
down position. Further, part of the head 148 of the piston 146 has an annular
surface
154. When the piston rod 146 rises due to water pressure entering the cylinder
149,
the annular surface 154 will contact an annular surface of an upper bushing
156
indicated at an upward portion of the water cylinder 149, which impedes the
movement of the piston 146. The spring 86 is seated on the bushing 156. A
bracket
76 attaches the water cylinder 149 to the hull 38 of the PWC 10. In another
region of
the rudder 716a is an attachment 158a, 158b that connects the backside of
rudder 716a
to a rod 118. Shown in phantom, the rod 118 is surrounded by a sleeve 160 that
is
connected to a distal end of the linking element 66a.
In this manner, the rudder 716a can pivot around an axis extending along the
piston 146 while allowing the rudder 716a to also raise up and down wherein
the
sleeve 160 slides over the pin 118 as the rudder 716a moves up and down
according
to the water pressure which is in the water line 136a. An opening in the hull
38 or in
some other equivalent structure, such as a bushing 162 mounted to the hull,
may allow
for the support of the linking element 66a.
To avoid building up too much water pressure in the water cylinder 149, and
to assist in washing and cleaning, the piston 146 and/or water cylinder 149
may leak
water purposefully. At least one hole and preferably four evacuation holes
(not
shown) may be placed in the top region of the water cylinder 149 for this
purpose.
Figures 14a through 14c are perspective views of the rudder 716a. Turning
first to Fig. 14a, the surface of rudder 716a, as illustrated generally by
174, comprises
various elevations that, in the preferred embodiment, peak at a point
indicated by 175.
Furthermore, the rudder 716a comprises a plurality of openings 172 on its
face. These
openings 172 are bounded by portions of the rudder 716a and also fins 170 that
connect the front surface structure of the rudder to a deeper structural
surface of the
21
30142120V1
CA 02333831 2001-02-05
rudder indicated by 173 and 177, respectively. The fins 170 also act as
structural
reinforcement for the rudder 716a. Angling the fins 170 will assists in moving
the
rudder 716a into the water, as described in the third embodiment. At a top
portion of
the rudder 716a is a flat extension 168 which provides a connecting means for
the
pivoting point 140 in order to enable the rudder 716a to pivot and assist in
steering the
PWC 10.
Figure 14b is another perspective view showing the openings 172 and the fins
170. The surface 174 of the rudder 716a is also shown. The openings 172 enable
the
rudder 716a to be turned in such a way that it may be effective in diverting
water
either on its outside surface 174 or on an inner surface indicated generally
by 171 in
Figure 14a. Thus, the rudder 716a is turned about the axis such that water
flows
across the inside surface 171. Water can flow through the openings 172 and
across
the fins 170 both to relieve pressure upon the rudder 716a, which may weaken
it
unnecessarily, and to allow the rudder 716a to participate in diverting enough
water to
1 S assist in steering the PWC 10. However, in the same regard, if rudder 716a
is turned
in such a way, for example, toward the port side to assist the PWC 10 in
steering to
the port direction, then water will flow across the front surface of rudder
716a
illustrated at 174. In such a case, water will flow over the front surface 174
and over
the surface 177 and out the back of the rudder 716a. In this manner, the
rudder 716a
may more fully participate in steering the watercraft whether water flows
across either
the front surface 174 or the rear surface 171 of the rudder 716a.
The leading edge 910 of the bottom surface 900 of the mdder 716a curves
upwardly to deflect floating obstacles, such as a rope, under the rudder 716a,
or to
help moving the rudder 716a up over solid obstacles, such as a rock, to avoid
entangling or damaging the rudder 716a. The trailing edge 920 of the bottom
surface
900 of the rudder 716a curves upwardly as well. This curve accelerates the
flow of
the water following the bottom surface 900, thus creating a low pressure
region. This
low pressure region assists in moving the rudder 716a into an operative
position.
Figure 14c illustrates a top view of rudder 716a. The hinged connection 140 is
illustrated as the point around which the rudder pivots. Fig. 14c provides a
general
understanding of the shape of the top surface 168. The top surface 168
preferably has
an airfoil shape to increase the efficiency of the rudder 716a when turning.
However,
22
30142120V 1
CA 02333831 2001-02-05
this shape shown in Figs. 14a through 14c is not necessarily meant to be
limiting but
is only exemplary of possible configurations and locations of cavities or
openings 172
within the rudder 716a that help direct water over surfaces or through the
rudder
where necessary. It is contemplated that other configurations may be available
or
used in connection with these general ideas.
Figures 1 Sa through 15c illustrate a seventh embodiment of the present
invention. As in earlier embodiments, the rudders 816a and 816b are connected
via
hinged portions 68a and 68b to the hull 38 at a location spaced a certain
distance from
the end of the rudders 816a, 816b. This offset position, which places the
fulcrum
away from the end of the rudders 816a, 816b, makes it easier to force the
rudders
816a, 816b out into the flow of water. Figures 15a through 15c illustrate a
clutch
mechanism in which both rudders 816a, 816b may be moved simultaneously in
order
to assist in steering during throttle operation. Furthermore, in this
embodiment, using
the clutch system enables both rudders 816a and 816b to remain inoperative
when
they are not needed for steering purposes. The rudders 816a, 816b may be any
of the
rudder embodiments disclosed herein or other configurations.
As shown in Fig. 15a, a slider 186 includes a slot opening 192. While slider
186 and the clutch mechanism are shown on top of the nozzle, the clutch system
could
also be below the nozzle. The slot opening 192 includes two regions 194, 196
for
receiving a locking pin 188. When the pin 188 is in the first unlocked region
196, the
pin 188 slides and does not engage the slider 186. The second locking region
194, is
discussed below. The clutch system further comprises a pair of brackets 180a,
180b
connected to pivotal attachments 182a, 182b to the nozzle 18. Bracket 180a is
attached at one end by pivotal attachment 182a to the nozzle 18 and, at the
other end,
is attached to linking element 66a via a pivotal attachment at 184a. Bracket
180b is
attached to the nozzle 18 at pivotal attachment 182b at one end and is
attached to
linking element 66b at pivotal attachment 184b at the other end.
The locking pin 188 is attached to a transverse bracket 183 which is connected
at one end to pivotal point 184a and at the other end of pivotal point 184b
which, as
previously discussed, are respectively attached to brackets 180a, 180b and
linking
elements 66a, 66b. When the locking pin 188 is not engaged with the slider
186, or
the locking pin 188 is in the non-engaging portion of the opening 196, as
illustrated in
23
30142120V1
CA 02333831 2001-02-05
Figs. 15a and 15b, movement of the nozzle 18 will not cause the rudders 816a,
816b
t0 mOVe.
The non-engaged mode of operation is further illustrated in Fig. 1 Sb. In Fig.
15b, the pin or bolt 188 is allowed to slide through the slider opening 196 as
the
S nozzle 18 is moved back and forth. As the pin 188 slides through the lower
region of
opening 196, it does not engage the transverse element 183 in order to affect
the
motion of movement of rudder 816a, 816b. In this non-engaging mode, the slider
186
does not engage the pin 188 and is not set within the cover 190. The brackets
180a,
180b prevent the linking elements 66a, 66b from moving the rudders 816a, 816b
into
inactive or inoperative positions. In this mode, the nozzle 18 moves left or
right
without moving the rudders 816a, 816b since locking pin 188 is not engaged in
the
engaging portion 194 of the slot opening 192 within the slider 186. This is
because
the slider 186 moves freely to the left and right in connection with the
movement of
the nozzle 18, but does not engage the locking pin 188 and thus does not
engage the
linking elements or the movement thereof in order to actuate the rudders 816a,
816b.
Figure 15c illustrates the locking pin 188 engaged with the cavity 194. When
the transverse element 183 is engaged via locking pin 188 to the slider 186,
it enables
the linking elements 66a, 66b to move as the nozzle 18 rotates around pivotal
point
26. W this manner, both rudders 816a, 816b simultaneously rotate around their
respective hinges 68a, 68b since they are connected to the non-telescoping
structures
of the linking elements 66a, 66b.
Figure 16 illustrates a side view of the clutch mechanism disclosed in Figs.
1 Sa through 1 Sc. A nozzle rudder 204 is positioned inside the nozzle 18 and
is
approximately 3mm wide. The linking element 66a and pivotal connecting portion
184a are connected and stacked with the bracket 180a and transverse connecting
element 183. Also, the cover portion 190 covers a portion of the slider 186 in
the
linked position. In addition, the nozzle rudder 204 is pivotally attached to
the nozzle
18 at a pivot point 206 and an extension flange 208 extends from the top of
the nozzle
rudder 204. A spring 200 is attached at one end to the flange 208 and biases
the
rudder 204 down in the water. When the speed of the water, i.e., the dynamic
pressure of the water, is high enough, the water causes the rudder 204 to
rotate around
pivotal axis 206. Preferably, the rudder 204 would be fully positioned at a
dynamic
24
30142120V l
CA 02333831 2001-02-05
pressure corresponding to a motor speed of between about 3500 and 5500 RPM
under
normal operating conditions. Most preferably, the locking pin 188 engages the
opening 192 when the dynamic pressure corresponds to a motor speed of about
4500
RPM under normal operating conditions.
S Spring 200 is connected at its other end via a flange 210 to cover 190.
Cover
190 is attached to the nozzle 18 through a screw or similar attachment means
202.
When water flows through the nozzle 18 at high speeds, the water will force
the
nozzle lever 204 rearward in the same direction as the water flow. The effect
of the
flow of water through the nozzle 18 causes the nozzle lever 204 to pivot about
point
206 and to draw forward the slider 186 thus causing the pin 188 to engage the
slider
opening 196. This prevents the linking element 66a, 66b from causing the
rudders
816a, 816b to pivot out into the path of the water and thus participate in
steering the
PWC 10.
The locking pin 188 is mounted on the transversal link 183 that is connected
at
both ends to the linking elements 184a, 184b, respectively. The transversal
link 183
connects the left and right rudders 816a, 816b and linkage elements 66a, 66b
such that
when the locking pin 188 is not engaged, the locking pin 188 is free to move
sideways
back and forth without manipulating the rudders 816a, 816b. To engage the
rudders
816a, 816b, the spring 200 stiffness can be adjusted so that the nozzle rudder
204 will
move into its fully down position when the water pressure corresponds to the
speed of
the motor reaching 2500 RPM under normal operating conditions. When the nozzle
rudder 204 is down, the slider 186 is in its rear position and the locking pin
188 is
engaged in the locking portion 194 of slot opening 192.
The shape of the slot opening 192 can be modified or adjusted to vary the
corresponding motor speed range (RPMs) in which the nidders 816a, 816b are
engaged by the clutch mechanism. Preferably, the locking pin 188 engages the
locking portion 194 of the opening 192 when the corresponding motor speed is
between 3000 and 4500 RPM. It is also contemplated that the shape of the slot
opening 192 could be inverted to engage locking pin 188 at pressures
corresponding
to high motor speeds only. Such a clutch mechanism could also be used in
systems
other than off power steering systems, such as a trimming system or any other
suitable system known to one skilled in the art.
30142120V 1
CA 02333831 2001-02-05
Figure 17 illustrates results of fields tests performed on PWCs and shows the
effect of flaps/rudders or no flaps/rudders and of either driving straight or
turning
while decelerating the PWC. The tests were performed using the rudder
configuration
shown in Figs. 14 and 18. The speed and miles per hour are on the vertical
axes and
the distance in feet it took the PWC to decelerate from a speed of around 58
mph
down to 10 mph are on the horizontal axes. Line A illustrates no rudders being
used
and the PWC traveling in a straight line. In this case, approximately 300 feet
were
required for the PWC to slow from a speed of 58 mph to 10 mph. Line B shows
that
it took 270 feet for a PWC to slow from 58 mph to 10 mph when no rudders were
used and the PWC was turned at the same time as it was decelerating.
Line C illustrates the effect of having two rudders starting in a raised
position
and activated to lower into the water and turning the PWC while slowing. In
this
case, it took approximately 160 feet for the PWC to slow from a speed of 58
mph to
10 mph. This is similar to the stopping distance of a car. Figure 17
illustrates the
great advantages of using rudders according to the present invention in order
to assist
in decelerating the PWC.
Figures 18-24 show an eighth embodiment of the invention. In this eighth
embodiment, the PWC 10 has an alternative construction for connecting the
nozzle
900 to the rudders. Figure 18 is a top view showing only one lateral half of
the PWC
10 and with the deck removed. Also, the rearward portion of the tunnel 902 is
cut
away and the nozzle therein is shown schematically at 904. In Figure 18, a U-
shaped
bracket 906, a generally vertically extending flexible member 908 made from
Delrin~, a through-hull fitting 909, a rigid stainless steel rod 910 housed in
a rubber
tube 912, an X-shaped bracket 914, a fluid T-connector 916, and a pair of
rubber
hoses 918, 920 are all shown.
The nozzle 904 is pivotally mounted for directing the pressurized stream of
water to provide steering in the same manner as described above or in any
other
suitable manner. The U-shaped bracket has a laterally extending portion 922
with a
pair of vertically extending portions 924, 926 on opposing ends thereof. The
center of
the laterally extending portion 922 is pivotally connected to the underside of
the
nozzle so that pivotal movement of the nozzle shifts the U-shaped member 906
generally laterally. Specifically, pivoting the nozzle 904 clockwise shifts
the U-
26
30142120v1
CA 02333831 2001-02-05
shaped member 906 laterally to the port side of the PWC 10. Likewise, pivoting
the
nozzle 904 counterclockwise shifts the U-shaped member 906 laterally to the
starboard side of the PWC 10. The U-shaped member is pivotally connected to
the
underside of the nozzle 904 by a single bolt 928 inserted through a bore in
the general
center of the laterally extending portion 906. A sleeve 930 is received around
the bolt
928 and abuts against the underside of the nozzle 904. The U-shaped member 906
can slide vertically along the exterior of the sleeve 930 so that vertical
force
components applied to the U-shaped member 906 are not transmitted directly to
the
nozzle 904.
Figure 19 shows the manner in which the U-shaped member 906 is connected
to flexible member 908 and the manner in which the flexible member 908 is
connected to rod 910. An identical construction for interconnecting these
elements is
provided on the starboard side of the U-shaped member 906. The vertical
portion 924
of the U-shaped member 906 has a bore therethrough and the lower end portion
of the
flexible member 908 has a bore therethrough. These bores are aligned and a
threaded
bolt 932 is inserted through the aligned bores. The bore in the flexible
member 908 is
counterbored and a wear resistant washer is received in the bore adjacent the
head of
the bolt 932 to facilitate pivotal movement. A nut 934 is threaded onto the
bolt 932
and tightened. This pivotally connects the flexible member 908 to the U-shaped
member 906. The pivotal connection allows for some relative movement to occur
between the U-shaped member 906 and the flexible member 908.
The flexible member 908 has a perpendicularly extending portion 936 at the
upper end thereof. Portion 936 has a threaded bore (not shown) formed therein.
The
sleeve 912 is inserted into a hole in the vertical wall of the tunnel 902 and
has a flange
942 extending radially therefrom inside the tunnel 902. The flange 942 has an
annular sealing ridge 944. The fitting 909 is inserted from the tunnel
interior into the
open end of sleeve 912 and is secured to the tunnel wall by a series of bolts
938. The
fitting 909 holds the flange 942 of tube 912 against the tunnel wall so that
the ridge
944 is provides a seal to substantially prevent water to leak from the tunnel
interior
into the main hull cavity. The fitting 909 has a bore 940 extending
therethrough. The
perpendicular portion 936 of the flexible member extends partially into the
bore 940
from the tunnel interior. The rod 910 extends through the tube 912, into the
bore 940,
27
30142120v1
CA 02333831 2001-02-05
and is received in the bore formed in the perpendicular portion of the
flexible member
936. The end of the rod 910 is threaded so that the rod 910 is retained in the
perpendicular portion's bore by threaded engagement. A low friction tape, such
as
conventional masking tape, is wrapped around the threads of the rod so that
some
rotational play can occur between the rod 910 and the flexible member 908. By
this
connection, as the U-shaped member 906 moves laterally during the pivotal
movement of the nozzle 904, the rod 910 will be pushed/pulled within the
sleeve 912,
as dictated by the movement of the nozzle 904 and the U-shaped member 906.
Figures 20 and 21 show an integrated piston/bracket unit 950, which
comprises a piston assembly 952 and a bracket 954. The bracket 954 has four
mounting bores 956, a piston fluid port 955 extending from the inner surface
thereof,
and a rod receiving portion 957 extending from the inner surface thereof. Four
bores
corresponding to mounting bores 956 are formed on the outer wall of the hull
and the
X-bracket 914 has another set of four corresponding mounting bores. The X-
bracket
also has a center mounting bore and the hull has a corresponding mounting bore
centered with respect to its other four bores. To connect the brackets 914 and
954 to
the hull, the X-bracket 914 is placed on the inner surface of the hull with
its mounting
bores aligned with the hull bores and a bolt is inserted through the X-bracket
center
bore and the hull center bore to initially mount the bracket 914 with the
other four hull
bores and the other four bracket bores aligned. The bracket 954 (along with
the entire
unit 950) is then placed on the exterior surface of the hull with the mounting
bores
aligned with the four hull bores and the four X-bracket bores. Four bolts 958
(Fig.
18) are then inserted through these aligned bores to attach the brackets 914
and 954 to
the hull wall. A soft rubber sealing member 959 is provided on the inner
surface of
the bracket 954 to reduce the chances of any water from leaking into the hull
through
the hull bores. Two additional bores are provided in the hull wall for
connecting the
rod 910 to the rudder 960 and the hose 918 to the piston assembly 952,
including one
bore spaced rearwardly from the X-bracket 914 and one bore spaced below from
the
X-bracket 914. The piston fluid port 955 extends through the bore below the X-
bracket 914 into the interior of the hull for connection to hose 918. The hull
bore
spaced rearwardly from the X-bracket 914 has the rod receiving portion 957
extends
therethrough when the unit 950 is mounted.
28
30142120V1
CA 02333831 2001-02-05
Figure 22 shows a rudder 960. The rudder 960 has a construction generally
similar to those discussed above and thus it will not be discussed in detail,
with the
exception of a brief discussion of how it attaches to the piston/bracket unit
950. The
rudder 960 has a pair of tabs 962, 964 extending laterally inwardly from the
inner
surface thereof. The tabs 962, 964 have bores 966, 968. The upper and lower
walls
have pivot mounting bores 970, 972. The lower bore 972 has an interlocking
projection 974 extending inwardly therefrom. The upper wall has a laterally
extending bore 976 that opens at an inner end to bore 970 and at its outer end
to the
exterior of the rudder 960. The manner of connection will be discussed after
detailing the piston assembly 952 and its operation.
Referring to Fig. 21, the piston assembly 952 includes a piston rod 978 that
moves generally vertically within a piston cylinder 980. A piston head 982 is
frxedly
mounted to the piston rod 978. Specifically, the piston head 982 has a pair of
diametrically opposed bores and the rod 978 has a pair of diametrically
opposed
bores. A spring pin 984 is inserted through the bores to fix the piston head
982 on the
rod 978. A coil spring 986 is received between the upper end of the cylinder
980 and
the piston head 982 to bias the piston head downwardly. The lower end of the
cylinder 980 is communicated to the pressurized water in venturi 904 by the
piston
fluid port 955, which is connected to hose 918, which in turn receives
pressurized
water from the impeller in the tunnel via T-connector 916 and its hose
connected to
the venturi. Thus, when the water is pressurized by impeller, water flowing
into the
cylinder 980 forces the piston head 982 upwardly against spring 986. As will
be
discussed below, because the rudder 960 is pivotally connected to the piston
rod 978,
it will be raised upwardly into its inoperative position. Holes (not shown)
are
provided in the upper end of the cylinder 980 to allow and water and/or debris
that has
entered the portion of the cylinder 980 above the piston head 982 to be
expelled from
the cylinder 980 during its upward movement.
The lower end of the cylinder 980 has a threaded opening that is sealed with a
threaded plug 988. A hard plastic wear insert 990 is mounted within the plug's
opening to reduce wearing on the plug 988 by the vertical movement of the
piston rod
978. A pair of split sealing rings 992, 994 are mounted within the wear insert
990 to
provide a seal against the rod 978. The sealing rings 992, 994 are made out of
hard
29
30142120V1
CA 02333831 2001-02-05
plastic to prevent them from wearing down or sticking to the piston rod 978,
as may
happen if using a soft rubber.
The piston head 982 has an annular groove in which a pair of split sealing
rings 996, 998 are received. These sealing rings 996, 998 provide a seal
between the
piston cylinder interior surface and the piston head 982. One on side of the
piston
head groove is a projection 1000 that extends downwardly into the vertical
split of the
upper sealing ring 996. This projection keeps the upper sealing ring 1000 from
rotating. A similar projection (not shown) is provided on the other side of
the piston
head groove and extends upwardly into the vertical split groove of the lower
sealing
ring 998, which keeps the lower ring 998 from rotating. As a result of these
projections, the splits in the rings 996, 998 are prevented from becoming
aligned,
which functions to provide for a better seal. Similar projections can be
provided on
wear insert to prevent rings 992, 994 from having their vertical splits
aligned.
The interior of the cylinder 980 is tapered, wider at the bottom and narrower
at
I 5 the top. As a result, the seal between the piston head 982 and the piston
interior
surface is relatively tight to prevent pressure loss. However, as the head 982
travels
downwardly, a gap is formed between the piston head 982 and the piston
interior
surface. This gap enables water underneath the piston head 982 to flow
upwardly
through the gap to the piston region above the piston head 982, which reduces
resistance to the lowering of the piston head 982. This allows for faster
movement of
the rudder 960 connected to the piston rod 978 down to its operative position.
Refernng to Figures 21 and 22 together, the upper end of the piston rod 978
has a bore 1004 formed therethrough. The upper end of the piston rod 978 is
received
in the upper pivot mounting bore 970 of the rudder 960. A threaded rod (not
shown is
threaded into aperture 976 and inserted into bore 1004 to lock the upper end
of the
piston rod 978 relative to the rudder 960. The lower end of the piston rod 978
is
notched to receive projection 970 therein upon receipt in bore 972. There two
connections ensure that the piston rod 978 and the rudder 960 are locked
together both
rotationally and axially, thus enabling the piston rod 978 and rudder 960 to
move
together both pivotally and vertically.
30142I20v1
CA 02333831 2001-02-05
Referring to Figures 22 and 23 together, a bolt 1006 is inserted through the
bores 966, 968 of tabs 962, 964. A connector 1008 positioned between the two
tabs
962, 964 has a bore in which the bolt 1006 is received. The tube 912 has a
radially
extending flange 1010 that is positioned exteriorly of the hull wall. The
flange 1010
S has an annular sealing element 1012 that is engaged against the hull wall
exterior to
inhibit water flow into the hull. The tube 912 leads to the tunnel interior,
where the
presence of water is acceptable. The rod 910 protrudes from the tube 912 and
is
threadingly engaged within a bore in connector 1008. This establishes a
mechanical
connection between the rod 910 and the rudder 960 whereby movement of the rod
910
pushes the rudder inwardly and outwardly in a pivoting manner about the piston
rod
978. As a result, the lateral movement of the U-shaped member 906 is able to
affect
corresponding pivotal movement of the rudder 960 through the flexible member
908,
the rod 910 and the connector 1008.
The system on the starboard side of the PWC is identical to the one described
in this ninth embodiment. Thus, the lateral movement of the U-shaped member
906 is
able to affect corresponding pivotal movement of both n>dders 960 through the
flexible members 908, the rods 910 and the connector 1008.
Figure 24 shows a cross-section of the T-connector 916. The T-connector 916
is designed to function as a valve to let water flowing back from the piston
950 to
flow into the tunnel 902 without becoming backed up. The connector 916
includes a
cylinder 1020, a tubular piston rod 1022 with an integral piston head 1024
slidably
mounted in the cylinder 1020, a spring 1026 biasing the piston head upwardly,
and a
plug 1028 closing the bottom opening of the cylinder 1020. The piston rod 1022
has
a fluid passageway 1029 therethrough.
At the lower end of the piston rod 1022 is a connector 1030 that attaches to a
flexible hose 1032 which in turn is connected to the venturi to enable
pressurized
water from in the venturi to flow upwardly through passageway 1029 and into
the
upper region of the cylinder 1020. This forces the piston rod 1022 and head
1024
downwardly past connection members 1034 and 1036 so that pressurized water
from
the venturi flows into these connection members 1034, 1036. The water is then
communicated by hoses 918 to their respective piston assemblies 952 to
maintain
their respective rudders 960 in their inoperative positions. The hose 1032
flexes to
31
30142120V 1
CA 02333831 2001-02-05
accommodate this downward movement. As the water pressure in the venturi
drops,
the spring 102 forces the piston head 1024 and rod 1022 upwardly. As the
piston
head 1024 passes the connectors 1034, 1036, the water in the hoses 918 can
flow back
into the piston region underneath the piston head 924 and out through a port
1040
formed in the cylinder 1020. This allows the piston assemblies 952 to
responsively
push their respective rudders 960 to their operative positions.
The T-connector is connected to the underside of the tunnel wall by bolts 1042
inserted through flanges 1044.
From the previous descriptions, a person skilled in the art should understand
that it is possible to make a kit to retrofit a watercraft with an off power
steering
system. The kit would include at least a linking member, a rudder and a
bracket to
attach the rudder to the hull. The rudder could be of any type described
above, as
well as any other type known. With such a kit, the standard nozzle on the
watercraft
to be retrofitted would require some machining to allow attachment of the
linking
member to it. Preferably, the kit would include a nozzle adapted for the
attachment of
the linking element. The kit can also include a clutch mechanism as shown in
Figure
16. The linking member can be of the non-telescopic kind, in which case a
flexible
member and a U-shaped member, as shown in Figure 18, could be added to the
kit. If
the off power steering system kit is of the type where the rudders can move
vertically
out of the water, the kit should include a spring. A piston and a water line
could also
be added to such a kit.
Although the above description contains many specific examples of the
present invention, these should not be construed as limiting the scope of the
invention
but as merely providing illustrations of some of the presently preferred
embodiments
of this invention.
Additionally, this invention is not limited to PWC. For example, the vertical
rudder steering systems disclosed herein may also be useful in small boats or
other
floatation devices other than those defined as personal watercrafts. The
propulsion
unit of such craft need not be a jet propulsion system but could be a regular
propeller
system. In such a case, the water lines between the nozzle and the flaps or
rudders
could be replaced with lines that provide actuating control to the rudders
without
32
30142120V1
CA 02333831 2001-02-05
using pressurized water. For example, the lines could provide an electrical
signal to
electrically operate pistons or solenoids. Also, the rudders need not have any
connection to the helm or the nozzle. Instead, the rudders could be operated
by an
actuator separate from the helm. For example, a small joystick could be used
to
deploy the rudders and determine the direction of steering. Thus, the scope of
the
invention should be determined by the appended claims and their legal
equivalents
rather than by the examples given.
33
30142120V1
