Note: Descriptions are shown in the official language in which they were submitted.
1057P131CA
STEERING ASSEMBLY FOR A MARINE VESSEL WITH
VERTICALLY OFFSET PROPULSION UNTIS
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to a steering assembly for a marine
vessel and, in
particular, to a steering assembly for a marine vessel with vertically offset
propulsion units.
Description of the Related Art
[0002] Marine vessels are often provided with more than one propulsion
unit.
Typically tie bars are used to mechanically couple the propulsion units. U.S.
Pat. No.
6,406,340 to Fetchko et al. and U.S. Pat. No. 7,128,626 to Dudra et al., both
disclose using
a tie bar to couple propulsion units on a marine vessel. This allows the
propulsion units to
be steered simultaneously.
[0003] It is also known to provide steering assemblies which accommodate
vertically
offset propulsion units. U.S. Pat. No. 6,699,082 to Zeigler et al., discloses
a steering
assembly using spacers to accommodate vertical offsets between propulsion
units.
However, in the steering assembly disclosed by Zieger et al., the tie bars are
connected to
the propulsion units on a horizontal plane.
[0004] There is accordingly a need for an improved steering assembly for
marine
vessels with vertically offset propulsion units.
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SUMMARY OF THE INVENTION
[0005] Some embodiments may provide an improved steering assembly for a
marine
vessel which has vertically offset propulsion units.
[0006] Some embodiments may provide a steering assembly having improved
steering
actuators provided with upwardly or downwardly extending tie bar mounts to
reduce the
slope of tie bars connecting adjacent, vertically offset propulsion.
[0007] There is accordingly, in some embodiments, a hydraulic steering
actuator
provided. The actuator may include: a cylinder and piston rod reciprocatingly
mounted
within the cylinder and extending through the cylinder for movement along a
piston rod
axis; a pair of spaced-apart cylinder arms extending radially outward of the
cylinder and a
pivot plate extending between the cylinder arms; a pair of support arms which
are pivotable
about a tilt axis and are connected to opposite ends of the piston rod to
allow arcuate
movement of the piston rod about the tilt axis while maintaining the piston
rod axis parallel
to the tilt rod axis; and a tie bar mount disposed on the cylinder and having
an aperture
extending therethrough for the receiving a connecting member which connects a
tie bar to
the tie bar mount, wherein the aperture extends axially in a direction
substantially
perpendicular to the piston rod axis.
[0008] In some embodiments, a hydraulic steering assembly for applying a
force to
tillers of at least two marine propulsion units my be provided. The the
hydraulic steering
assembly may include: a first hydraulic steering actuator operatively coupled
to a tiller of
a first propulsion unit, the first hydraulic steering actuator including a
cylinder and piston
rod reciprocatingly mounted within the cylinder and extending through the
cylinder for
movement along a piston rod axis; a pair of spaced-apart cylinder arms
extending radially
outward of the cylinder and pivot plate extending between the cylinder arms; a
pair of
support arms which are pivotable about a tilt axis and are connected opposite
ends of the
piston rod to allow arcuate movement of the piston rod about the tilt axis
while maintaining
the piston rod axis parallel to the tilt rod axis; and a tie bar mount
disposed on the cylinder
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and having an aperture extending in an axial direction substantially
perpendicular to the
piston rod axis thereof; a second hydraulic steering actuator operatively
coupled to a tiller
of a second propulsion unit, the second hydraulic steering actuator including
a cylinder and
piston rod reciprocatingly mounted within the cylinder and extending through
the cylinder
for movement along a piston rod axis; a pair of spaced-apart cylinder arms
extending
radially outward of the cylinder and a pivot plate extending between the
cylinder arms; a
pair of support arms which are pivotable about a tilt axis and are connected
to opposite
ends of the piston rod to allow arcuate movement of the piston rod about the
tilt axis while
maintaining the piston rod axis parallel to the tilt rod axis; and a tie bar
mount disposed on
the cylinder and having an aperture extending axially in a direction
substantially
perpendicular to the piston rod axis thereof; and a tie bar coupling the tie
bar mount of the
first hydraulic actuator to the tie bar mount of the second hydraulic
actuator, wherein a first
connecting member which connects the tie bar to the tie bar mount of the first
hydraulic
actuator extends in a direction substantially perpendicular to the tilt axis
of the first
hydraulic actuator and a second connecting member which connects the tie bar
to the tie
bar mount of the second hydraulic actuator extending in a direction
substantially
perpendicular to the tilt axis of the second hydraulic actuator.
[0009] The upwardly and downwardly extending tie bar mounts reduce the
slope of tie
bars connecting adjacent, vertically offset propulsion units. The asymmetrical
shape of the
tie bar mounts provide an original equipment manufacturer (OEM) with the
advantage of
only having to use a single component regardless of whether the tie bar mount
will extend
in an upwardly or downwardly direction relative to the piston rod axis of
steering actuator.
BRIEF DESCRIPTIONS OF DRAWINGS
100101 The invention will be more readily understood from the following
description
of the embodiments thereof given, by way of example only, with reference to
the
accompanying drawings, in which:
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[0011] Figure 1 is a perspective view of a marine vessel provided with a
plurality of
propulsion units and an improved steering assembly;
[0012] Figure 2 is a perspective view of the improved steering system and
propulsion
units;
[0013] Figure 3 is another perspective view of the improved steering system
and
propulsion units;
[0014] Figure 4 is a perspective, partially broken away, view of a middle
hydraulic
steering actuator of the improved steering system;
[0015] Figure 4a is a partial cut away front view of the right side of a
steering actuator
similar to that shown in Figure 4;
[0016] Figure 5 is a view of the middle actuator of the improved steering
system;
[0017] Figure 5a is a partial broken away top view of the middle actuator
of Figure 5;
[0018] Figure 6 is a perspective view of a starboard side hydraulic
steering actuator of
the improved steering system;
[0019] Figure 7 is a perspective view of a port side hydraulic steering
actuator of the
improved steering system;
[0020] Figure 8 is a partial perspective view of an improved steering
system used with
two propulsion units;
[0021] Figure 9 is a partial perspective view of an alternate improved
steering system
used with two propulsion units; and
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[0022] Figure 10 is a partial perspective view of an alternate improved
steering system
used with three propulsion units.
DESCRIPTIONS OF THE PREFERRED EMBODIMENTS
[0023] Referring to the drawings and first to Figure 1, this shows a marine
vessel 10
which is provided with a plurality of propulsion units in the form of three
outboard engines
12, 14 and 16. However, in the other examples, the marine vessel 10 may be
provided with
any suitable number of inboard and/or outboard engines. It is common to see
two engines
and up to five engines in pleasure marine vessels. The marine vessel 10 is
also provided
with helm station 18 that includes a helm 20 for steering the marine vessel
10. The helm
is operatively connected to a hydraulic pump (not shown) and is part of a
hydraulic
steering system which is used to steer the marine vessel 10.
[0024] As best shown in Figure 2, the engines 12, 14 and 16 are mounted
on a transom
22 of the marine vessel 10, which is shown in fragment. The center engine 14
is mounted
15 inside a centrally disposed, recessed portion 24 of the transom 22. The
starboard and port
side engines 12 and 16 are mounted on opposite sides of the transom 22 outside
the recessed
portion 24. The center engine 14 is accordingly vertically offset with respect
to the
starboard and port side engines 12 and 16. A steering assembly indicated
generally by
reference numeral 26 mechanically couples the engines. This allows the engines
to be
20 steered simultaneously. The steering assembly 26, better shown in Figure
3, includes a
plurality of steering actuators 28, 30 and 32 together with tie bars 34 and 36
which connect
adjacent steering actuators. The steering actuators have a substantially
similar structure and
function in a substantially similar manner. It should be understood that not
all transoms 22
are at different heights as shown in Figure 2. Thus, vessels where the transom
22 is at the
same height along its length may also be used in accordance with other
embodiments. After
reading the disclosure contained herein, one of ordinary skill in the art will
understand what
modifications may be necessary to practice the features contained herein with
such a vessel.
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[0025] Figures 4 and 4a show the middle steering actuator 30 in greater
detail. The
middle steering actuator 30 includes a hydraulic cylinder 38 with a piston rod
40
reciprocatingly mounted therein allowing for relative movement of the cylinder
38 along a
piston rod axis 100. The cylinder 38 has a pair of spaced-apart cylinder arms
42 and 44
which extend radially outward of the cylinder 38. A pivot plate 46 is
pivotably connected
to each of the cylinder aims 42 and 44 by pivot pins 48 and 50. The pivot
plate 46 extends
between the cylinder arms 42 and 44 and the cylinder arms may pivot about the
pivot plate
46. Support arms 52 and 54 connect opposite ends of the piston rod 40 to a
tilt rod 56 of a
tilt tube (not shown) of the middle engine 14 which is shown in Figures Ito 3.
The support
arms 52 and 54 restrict axial movement of the piston rod 40 relative to the
marine vessel
10. The support arms 52 and 54 also allow arcuate movement of the cylinder 38
and piston
rod 40, about a tilt axis 105, while maintaining the piston rod axis 100
parallel to the tilt
axis 105.
[0026] Hydraulic conduits 58 and 60 hydraulically connect opposite ends
of the
cylinder 38 to the helm pump (not shown). Hydraulic fluid pumped from the helm
pump
actuates the cylinder 38 to reciprocate linearly relative to the piston rod
40. One of ordinary
skill in the art after reviewing this disclosure will understand how the
hydraulic fluid is
pumped from the helm pump. In particular, the piston rod 40 remains axially
stationary
relative to the marine vessel 10, shown in Figure 1, while the cylinder 38
reciprocates
relative to the marine vessel 10.
[0027] Referring to Figure 2, a steering member in the form of tiller 62
of the middle
engine 14 is pivotably connected to the pivot plate 46 of the middle steering
actuator 30.
The relative linear movement of the cylinder 38 is thus transmitted to the
tiller 62. This
causes the tiller 62 to pivot about a steering axis 110 and the middle engine
14 to be steered.
The starboard and port engines 12 and 16 are steered in a similar manner by
the starboard
and port side steering actuators 28 and 32. Furthermore, movement by any one
of the
steering actuators is transmitted by the tie bars 34 and 36 to the other ones
of the steering
actuators, allowing the engines to be steered simultaneously. As thus far
described the
steering assembly 26 and steering actuators 28, 30 and 32 are conventional.
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[0028] However, as shown in Figure 4 and Figure 4a, which is a partial
cut away view
similar to what is shown in Figure 4, the middle steering actuator 30 is
provided with
asymmetrical tie bar mounts 64 and 66. The tie bar mounts 64 and 66 are each
provided
with an aperture 68 and 70, respectively. The apertures 68 and 70 extend
axially in a
direction generally perpendicular to the piston rod axis 100. The tie bar
mounts 64 and 66
are substantially identical and one of the tie bar mounts 66 is shown in
greater detail in
Figures 5 and 5a. The tie bar mount 66 includes a first portion 72 and a
second portion 74
which extends angularly from the first portion in an upwardly direction
relative to the
piston rod axis 100. In this example, the first portion 72 of the tie bar
mount 66 has
generally quadrilateral shape and the second portion 74 of the tie bar mount
66 has
generally symmetrical, curved shape. Line 115 represents the divide between
the first
portion 72 of the tie bar mount 66 and the second portion 74 of the tie bar
mount 66.
[0029] As shown in Figures 5 and 5a, connecting members in the form of
bolts 76
secure the tie bar mount 66 to the cylinder 38 of the middle steering actuator
30. The bolts
76 extend in a direction generally perpendicular to the piston rod axis 100. A
projection 77
on the bolt 76 may engage a groove 78 in an end gland 80 of the cylinder 38.
The end gland
80 may have grooves 81 to accommodate 0-rings 83. The bolt 76 maintains the
gland 80
in position and prevents the gland 80 from becoming decoupled from the
cylinder 38 in
response to frictional and vibratory forces during operation of the hydraulic
steering
system. Preferably, only a bolt 76 near a center line 120 of the cylinder 38
engages the
grove 78 in the end gland 80. The center line 120 is typically coaxial with
the piston rod
axis 100 and the cylinder 38 is provided with grooved end glands at both ends
thereof
[0030] A connecting member in the form of bolt 82 extends through the
aperture 70 in
the tie bar mount 66 and a ball joint 84 in the tie bar 36. The bolt 82
connects the tie bar
mount 66 to the tie bar 36, allowing the middle steering actuator 30 to be
connected to the
port side actuator 32 as shown in Figure 2. The bolt 82 extends in a direction
generally
perpendicular to the piston rod axis 100 and allows the tie bar 36 to be
connected to the tie
bar mount 66 on a vertical plane so as to permit pivoting of the tie bar 36
about a generally
horizontal axis 125 along the bolt 82. The ball joint 84 provides an
articulate connection
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between the tie bar mount 66 and the tie bar 36. Other embodiments may use
other
articulating joints as the features described herein are not limited to ball
joints only. The
articulate connection allows the tie bar 36 to reciprocate along its
longitudinal axis when
the engines 12, 14 and 16 are moved back and forth as the marine vessel is
steered. The
.. middle steering actuator 30 is connected to the starboard side actuator 28
in a similar
manner by tie bar mount 64 and tie bar 34.
[0031] As shown in Figures 4, and 4a the middle steering actuator 30 is
further
provided with a pair set screws 86 and 88 which exert a compression force
against the pivot
pins 48 and 50, respectively. The set screws 86 and 88 provide a redundancy to
maintain
the pivot pins 48 and 50 in position. In other embodiments set screws may be
used to
provide a redundancy to maintain other pins or screws in position. For
example, set screws
may be used to provide a redundancy to maintain the bolts which secure the tie
bar mounts
to the cylinder in position.
[0032] Figure 4a shows a right side of a middle hydraulic steering
actuator of an
improved steering system similar to that shown in Figure 4. The tie bar mount
66 shown in
Figure 4a is slightly different than that shown in Figure 4. One of ordinary
skill in the art
will understand that modifications to the system shown in the Figures may be
done in
accordance with the invention. As shown in Figure 4a, 0-rings 89 may be
located near the
pivot pin 50. The pivot pin 50 may have a passageway 91 in order to provide an
escape
pathway for grease, air and/or other materials. The pivot pin 50 may be fit in
a flange
bushing 93. In some embodiments the flange bushing 93 may be plastic although
it is not
limited to plastic. The flange bushing 93 may butt against a washer 94. The
washer 94 may
be stainless steel but is not limited to that material.
[0033] Both the pivot pin 50 and the set screw 88 may have structure 96,
98 to allow a
tool to engage the pivot pin 50 and set screw 88 to turn them. In some
embodiments the
structure may be a hex broach 96,98 as shown in Figure 4a but it is not
limited to hex
broaches. The set screw 88 may have a groove 102 to accommodate an 0-ring 104.
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[0034] The starboard and port side steering actuators 28 and 32, best
shown in Figures
6 and 7, are substantially similar in structure and function in a
substantially similar manner
as the middle steering actuator 30. However, the starboard side steering
actuator 28 is
provided with only one tie bar mount 90 which extends in a downwardly
direction relative
to its piston rod axis 130. Likewise the port side steering actuator 32 is
provided with only
one tie bar mount 92 which extends in a downwardly direction relative to its
piston rod axis
135. The starboard side actuator 28 and port side actuators 32 are mirror
images and are
coupled to opposite sides of the middle actuator 30 by corresponding tie bars
34 and 36, as
shown in Figures 2 and 3. There is an articulate connection between each of
the tie bar
mounts and the tie bars to allow the tie bars to rotate about their points of
connection with
the tie bar mounts when the engines 12, 14 and 16 are moved back and forth
and/or tilted
as the marine vessel 10 is steered.
[0035] As best shown in Figure 2, providing the steering assembly 26 with
upwardly
and downwardly extending tie bar mounts 64, 66, 90 and 92 allows for improved
mechanical coupling of the vertically offset engines 28, 30 and 32. In
particular, the slope
of tie bars 34 and 36 relative to the horizontal, as represented by angles a 1
and a2, is
reduced and in some embodiments the tie bars may be completely horizontal. In
the
embodiment of the steering assembly 26 disclosed herein the engines 28, 30 and
32 are
vertically offset because the middle engine 30 is mounted in the recessed
portion 24 of the
transom 22. However, the steering assembly may also be used in situations
where a vertical
offset results because different types of engines are coupled, for example in
a steering
system including a primary propulsion unit and an auxiliary propulsion unit.
The steering
assembly may also be used in situations where there is no vertical offset.
When there is no
vertical offset the tie bar mounts may all extend in the same direction.
[0036] Figures 8-10 show that various embodiments of the invention may be
used with
a number of different engine configurations and component configurations. For
example,
Figure 8 is a partial perspective view of an improved steering system used
with two
propulsion units. Figure 9 is a partial perspective view of an alternate
improved steering
system used with two propulsion units. Figure 10 is a partial perspective view
of an
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alternate improved steering system used with three propulsion units. The
various Figures
shown herein show alternate configurations of tie bars 34 and steering
actuators 28, 30, 32.
Various embodiments in accordance with the invention may use the
configurations of tie
bars 34 and steering actuators 28, 30, 32 shown or other variations.
Additional numbers of
propulsion units other than the three shown and the specific configurations
shown may also
be used in some embodiments of the invention.
[0037] It will be understood by a person skill in the art that the terms
"upwardly", and
"downwardly" as used herein are used with reference to the upwardly and
downwardly
directions when the steering assembly is in use.
[0038] It will further be understood by a person skilled in the art that
many of the details
provided above are by way of example only, and are not intended to limit the
scope of the
invention which is to be determined with reference to follow claims.
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