Rudder for watercraft

Several embodiments of jet propelled watercraft including steering rudders pivotally supported by the steering nozzle of the jet propulsion unit for providing a steering affect at low speeds and when coasting. The steering rudder is selectively moveable between its steering position and non-steering position so as to permit unincumbered high speed operation. An arrangement is incorporated that permits the rudder to pivot automatically from its steering position to an out of the way position when an underwater obstacle is struck.

BACKGROUND OF THE INVENTION 
This invention relates to a rudder for a watercraft a more particularly to 
a selectively operable steering rudder for a jet propelled watercraft. 
The advantages of jet propulsion unit for watercraft are well acknowledged. 
Such jet propulsion units permit the watercraft to be employed in a very 
shallow body of water and have a number of other advantages. Normally, one 
way in which jet propelled watercraft are steered is by employing a 
pivotally supported steering nozzle at the discharge end of the jet 
propulsion unit which is steered so as to effect turning of the 
watercraft. This type of steering arrangement is extremely effective 
during most normal watercraft operation. However, when the watercraft is 
traveling at a relatively slow speed or when coasting, the operation of 
the steering nozzle may not provide sufficient force for effecting the 
desired steering of the watercraft. 
If a conventional steering rudder is employed in conjunction with jet 
propelled watercraft, the steering rudder can offset some of the 
advantages of a jet propulsion unit. That is, the steering rudder must be 
submerged in the body of water in which the watercraft is operating in 
order to effect steering operation. However, when the steering rudder is 
so submerged, it can be subject to damage. Since jet propelled watercraft 
have the advantage of being operable in very shallow bodies of water, the 
use of a steering rudder will obviate this advantage. In addition, the 
rudder could be damaged when beaching the watercraft. 
It is, therefore, a principal object to this invention to provide an 
improved steering arrangement for a jet propelled watercraft. 
When a steering rudder is employed, in addition to the aforenoted 
difficulties, the steering rudder also provides unnecessary drag during 
high speed operation. During this high speed operation, the steering 
thrust of the discharge steering nozzle is more than adequate to provide 
the desired steering effect and, therefore, the steering rudder is in fact 
unnecessary and undesirable. 
It is a further object to this invention to provide a steering rudder 
arrangement for a jet propelled watercraft that employs a conventional 
steering nozzle and in which the rudder may pivot upwardly to avoid damage 
if underwater objects are struck and which may also be selectively pivoted 
out of the water when traveling at high speeds and when the operation of 
the steering rudder is not required. 
SUMMARY OF THE INVENTION 
This invention is adapted to be embodied in a watercraft having a jet 
propulsion unit having a water inlet portion, an impeller portion and a 
discharge portion adjacent which a pivotally supported steering nozzle is 
positioned. A rudder is pivotally supported by the jet propulsion unit for 
movement between a submerged steering position and an elevated, generally 
out of the water position. Biasing means normally hold the steering rudder 
in its steering position. Control means are provided for selectively 
pivoting the steering nozzle between its steering position and its out of 
the water position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION 
Referring in detail initially to FIG. 1, a watercraft powered by a jet 
propulsion unit constructed in accordance with an embodiment of the 
invention is identified generally by the reference numeral 21. The 
watercraft 21 is comprised of a hull made up of a deck portion 22 and a 
lower hull portion 23 which may be formed from a suitable material such as 
a molded fiberglass reinforced resin or the like. This hull defines a 
passenger area 24 that is adapted to accommodate one or more riders 
including an operator that controls the watercraft by means of controls 
such as a steering wheel 25 positioned forwardly in the passenger 
compartment 24. 
An engine compartment 26 is positioned in the lower hull portion 23 to the 
rear of the passenger compartment 24 and contains a powering internal 
combustion engine 27 that is mounted on engine mounts 28. A bulkhead 29 is 
formed at the rear of the engine compartment 26 and defines a forward 
portion of a tunnel 31. Mounted within the tunnel 31 is a jet propulsion 
unit 32 which is driven, in a manner to be described, from the engine 27 
for propelling the watercraft 21. The upper extremity of the tunnel 31 is 
defined by an upper wall 33 which separates the passenger compartment 24 
from the tunnel 31. 
The watercraft 21 normally rides in a body of water, indicated by the water 
line 34 in the figures. 
Referring now in detail additionally to FIGS. 2 and 3, the 
interrelationship between the driving engine 27 and the jet propulsion 
unit 32 and the construction of the latter will be described. The engine 
27 has an output shaft 35 which extends through an opening 36 formed in 
the bulkhead 29. This shaft 35 is journalled by a bearing assembly 37 that 
is mounted in a bearing carrier 38 that is affixed to a combined transom 
plate and cradle assembly, indicated generally by the reference numeral 
39. The cradle assembly 39 includes a plate like portion that affixed in a 
suitable manner to the rear surface of the bulkhead 29 within the tunnel 
31. 
Rearwardly of the bulkhead 29 and within the tunnel 31, a universal joint 
assembly, indicated generally by the reference numeral 41 is provided 
which has a splined connection to the drive shaft 35. The universal joint 
assembly 41, as will be apparent, is provided so as to accommodate pivotal 
movement between the jet propulsion unit 32 and the remaining structure of 
the watercraft, for a purpose to be described. The universal joint 
assembly 41 couples the drive shaft 35 for rotation with an impeller shaft 
42 of the jet propulsion unit 32. 
The jet propulsion unit 32 includes a housing assembly made up of a water 
inlet portion 43 having a forwardly extending pilot portion 44 into which 
a bearing carrier 45 is slipped. The bearing carrier 45 carries a bearing 
46 and seal assembly that rotatably journals the forward end of the 
impeller shaft 42 where it is coupled to the universal joint 41. A further 
rear seal 47 is provided adjacent the bearing carrier 45 so as to seal the 
bearing assembly 46 from water which may enter the inlet portion 43 
through a downwardly facing inlet opening 48. 
As may be seen, the inlet portion 43 is defined by a generally horizontally 
extending flange 49 to which a grill-like inlet 51 is affixed in a 
suitable manner so as to permit water to be drawn into an inlet passageway 
52 formed by the water inlet portion 43. 
An impeller housing portion 53 is affixed to the water inlet portion 43 in 
an appropriate manner and an impeller 54 is affixed to the impeller shaft 
42 in the impeller section 53. A tail section 55 is also affixed to the 
impeller housing 53 and carries a plurality of straightening vanes 56 and 
a bearing assembly 57 for journaling the rear end of the impeller shaft 
42. Water is drawn by the impeller 57 through the downwardly facing inlet 
opening 48 and water inlet passage 52 and then is driven rearwardly across 
the straightening vanes 56. 
This water is then discharged through a convergent discharge nozzle 58 
which is affixed to a sleeve 59 which, in turn, encircles the impeller 
housing 53 and extension portion 55. A steering nozzle 61 is journalled at 
the rear end of the discharge nozzle 58 for pivotal movement about a 
vertically extending pivot axis defined by pivot pins 62. The steering 
nozzle 61 is connected by means of a wire actuator (not shown) to the 
steering wheel 25 for steering of the nozzle 61 and watercraft 21 in a 
well known fashion. 
Normally it is the practice to mount the jet propulsion unit 32 in a fixed 
position within the tunnel 31 of the watercraft 21. However, this means 
that the water inlet portion 48 will always be underwater even when the 
watercraft is not being operated. As a result, barnacles and other 
incrustation may form in the jet propulsion unit 32 that can adversely 
effect its performance. In order to avoid this, the jet propulsion unit 32 
is mounted for pivotal movement about a transversely extending horizontal 
axis from the position shown in solid lines in FIG. 2 to a raised out of 
the water position as shown in phantom lines in this figure. The structure 
for accomplishing this pivotal movement will now be described, again by 
primary references to FIGS. 1 through 3. 
The bearing carrier 45 is formed with a pair of forwardly extending arm 
portions 63 that receive pivot pins 64 for pivotally connecting the 
impeller housing portion 43 to the cradle and transom plate 39 and 
specifically to a bifurcated member 65 thereof. The pivot axis defined by 
the pivot pins 64 is coincident with the pivot axis of the universal joint 
41 so as to accommodate the pivotal movement. For protection, a flexible 
boot 66 encircles the universal joint 41 and is affixed to a cylindrical 
extension from which the member 65 is formed by means of a clamp 67. A 
rear clamp 68 connects the rear end of the boot 66 to the bearing carrier 
45 so as to complete the enclosure and sealing of the universal joint 41 
while permitting the afore described pivotal movement. 
It should be noted that the cradle portion 39 has a rearwardly extending 
portion 68 defined by a pair of parallel side walls 69 an a lower wall 71. 
An opening 72 is formed in this lower wall 71 and is aligned with the 
water inlet opening 48 of the jet propulsion unit 32 so that water may be 
freely drawn into the jet propulsion unit 32. A gasket or seal 73 is 
carried by the flange 49 of the inlet portion 43 of the jet propulsion 
unit 32 and provides sealing engagement with the cradle portion 71 around 
the opening 72 so as to insure against water leakage and to provide good 
efficiency for the operation of the jet propulsion unit. 
A pair of support arms 74 are pivotally connected at their forward ends by 
means of pivot pins 75 to the side walls 69 of the cradle portion. These 
arms 74 and pivot pins 75 are substantially coincident with the pivot axis 
defined by the pivot pins 64 and with the universal joint 41. The rear 
ends of the arms 75 are affixed by threaded fasteners 76 to bearing blocks 
77 which are, in turn, affixed to the support ring 59. 
A hydraulic motor assembly is provided for raising and lowering the jet 
propulsion unit 32 and this is comprised of a fluid pump driven by an 
electric motor 78 that is affixed to the bulkhead 29 within in the engine 
compartment 26. This hydraulic assembly delivers fluid under pressure 
selectively to a pair of hydraulic cylinders 79 which have their cylinder 
ends pivotally connected to trunions 81 of the transom plate and cradle 39 
by means of pivot pins 82. Piston rods 83 of the fluid motors 79 are 
connected to upstanding projection 84 of the support arms 74 by means of 
pivot pins 85. As should be readily apparent, expansion and contraction of 
the fluid motors 79 will effect raising and lowering of the jet propulsion 
unit 32. The jet propulsion unit 32 is raised when the watercraft is not 
in operation so as to prevent the incrustation previously referred to 
which might otherwise occur if the jet propulsion unit was kept in the 
water at all times. 
In order to provide added transverse support when the jet propulsion unit 
32 is in its driving position, the arms 74 have a pair of inwardly 
extending pins 86 that are received in notches 87 formed in upstanding 
portions 88 of the cradle assembly 39. 
In addition to be pivotal about the horizontally disposed pivot axis 
aforedescribed, the jet propulsion unit 32 or at least the inlet portion 
43 and impeller portion 53 may be rotated about the axis of the impeller 
shaft 42 in a manner as described in the co-pending application of Noboru 
Kobayashi, entitled "Water Jet Propulsion Unit", Ser. No. 735154, filed 
Jul. 22, 1991, which application is a continuation of his application Ser. 
No. 489 361, filed Mar. 6, 1990, now abandoned, which applications are 
assigned to the assignee hereof. The disclosure of that application is 
incorporated herein by reference. If the unit is so rotatable, an access 
opening 89 may be formed in the hull portion 33 for accessing the water 
inlet opening 48 and servicing it as described in the noted co-pending 
application. 
The use of the pivotally supported steering nozzle 61 provides very 
effective steering when the watercraft 21 is operating at speed. However, 
when operating at idle or when coasting, there is not significant 
discharge pressure in the steering nozzle 61 so as to effect good 
steering. To provide effective steering under these circumstances, the jet 
propulsion unit 32 is provided with a steering rudder, indicated generally 
by the reference numeral 91, which can be selectively placed into a 
steering position or placed in an above the water non-steering position. 
The steering rudder 91 is, in this embodiment, formed as a generally 
U-shaped member having a pair of depending rudder portions 92 
interconnected at their upper ends by a bridge 93. This construction 
appears in FIGS. 4 and 5 but also is shown in FIG. 1 through 3. As may be 
seen, the rudder portions 92 are provided with aligned apertures 94 that 
receive respective pivot pins 95 affixed to and extending outwardly from 
the sides of the steering nozzle 61. A pair of tension springs 96 are 
loaded between each of the rudder portions 92 and fixed lugs 97 carried by 
the steering nozzle 61 for normally holding the steering rudder 91 in its 
operative steering position. The springs 97 are trapped in apertures 98 
formed in the rudder portions 92 for this purpose. If an underwater 
obstacle is struck when the rudder 91 is in its steering position, such an 
obstacle being indicated at 99 in FIG. 4, the springs 96 will yield and 
permit the steering rudder 91 to pivot about the pivot pins 95 so as to 
clear the obstacle 99 without any damage to the rudder 91. Once the 
obstacle 99 is cleared, the rudder 91 will be returned to its steering 
position by the springs 96. 
Although the steering rudder 91 is very effective in providing steering 
forces when coasting or traveling at low speeds, it will provide 
unnecessary and undesirable drag when operating at high speed. As 
previously noted, the steering effect of the steering nozzle 61 is very 
effective at high speeds and hence the rudder 91 is not required under 
these circumstances. Therefore, there is provided an arrangement for 
pivoting the steering rudder 91 from its normal steering position to an 
elevated non-steering position at the selection of the operator. 
For this end, there is provided a cross pin 101 that extends between the 
rudder portions 92 and coupling member 102 is connected to the pin 101 and 
to a rod 103 which is actuated, in a means to be described, for pivoting 
the rudder 91 between its two positions. A mechanism as best shown in FIG. 
6 and which is identified generally by the reference numeral 103 is 
provided for achieving this operation. The mechanism 103 includes one end 
of a sheath 104 which is pivotally connected by means of a pair of pivot 
pins 105 to a bracket 106 carried at the lower end of the steering nozzle 
61. 
A cylindrical plunger member 107 is slideably supported within the sheath 
104 and contains a headed end 108 of the rod 103. A coil compression 
spring 109 acts between the headed end 108 and an end wall 111 of the 
cylindrical member 107 so as to normally maintain the rod 103 in the 
position shown in FIG. 6. 
A bowden wire 112 is connected at one of its ends to the cylindrical member 
107. The bowden wire 112 extends through the sheath 104 upwardly through 
the tunnel 31 and to the passenger compartment 24 wherein it is connected 
to a control handle 113. The control handle 113 has a shank portion 114 
with a pair of diametrically opposed lugs 115 (FIGS. 9 and 10). This shank 
portion passes through a cylindrical opening 116 formed in a retainer 
member 117 that is fixed suitable to a dash panel 118 at one end of the 
sheath 104 in which the wire actuator 112 reciprocates. The opening 116 is 
formed with slots 119 and when the handle 113 is rotated so as to aligned 
its lugs 115 with the slots 116, the handle 113 may be pulled outwardly to 
lower the steering rudder 91 in a manner to be described. The steering 
rudder 91 is then locked in the position by rotating the handle 113 again 
through 90.degree.. 
The solid line view of FIG. 4 and FIG. 6 show how the mechanism appears 
when the steering rudder 91 has been locked in its steering position by 
pulling of the handle 113 to the rudder steering position as shown in 
phantom in FIG. 9. When this occurs, the tubular members 107 is pulled 
into the sheath 104 and the spring 109 will act together with this to 
bring the steering rudder 91 to its steering position. In addition to the 
spring 96 yielding when an underwater obstacle is struck, the spring 109 
will also yield so that the rod 103 may move to the position shown in FIG. 
7 without necessitating in concurrent movement of the operating handle 
113. 
If, however, the operator wishes to move the steering rudder 91 to its out 
of the water position for steering operation, the handle 113 is rotated to 
90.degree. and is pushed inwardly to the solid line position shown in FIG. 
9. This force on the wire actuator 112 will cause the rod 103 to be urged 
outwardly as the tubular member 107 slides rearwardly as shown in FIG. 8. 
The handle 113 is then rotated again through 90.degree. to lock it in the 
non-rudder steering mode. Hence, it should be readily apparent that the 
described construction is very effective in permitting the operator to 
select whether or not the device will be operated in the rudder steering 
mode. 
FIGS. 11 through 14 show another embodiment of the invention which, insofar 
as the construction of the jet propulsion unit 32 and its association with 
the watercraft 21 is the same as the previously described embodiment. For 
that reason, these portions of the construction have not been illustrated 
and further description of them is not believed necessary to understand 
the construction and operation of this embodiment. 
This embodiment, however, differs from the previously described embodiment 
in two main regards. In the first instance, in this embodiment there is 
only provided a single steering rudder, indicated generally by the 
reference numeral 151 which is mounted, in a manner to be described, as 
the lower end of the steering nozzle 61. In addition, the operation of the 
rudder 151 is accomplished in such a way so as to avoid the necessity of 
the spring connection device of the type shown in FIGS. 6 through 8 
including the spring 109 and sliding tubular member 107 of the previously 
described embodiment. 
In this embodiment, a mounting bracket 152 is affixed to the underside of 
the steering nozzle 61 and has a bifurcated portion that receive a pivot 
pin 153 which pivotally supports the steering rudder 151 on the bracket 
152. 
The wire actuator 112 is connected directly to a bifurcated member 154 and 
carries at its rearward end a pin 155 that extends through an arcuate slot 
156 formed in the rudder 151. A pair of coil compression springs 157 are 
connected at one end to the pin 155 and at their other ends to a pair of 
pins 158 that are affixed to opposite sides of the rudder 151. 
When the handle 113 is pulled outwardly to effect rudder steering, the wire 
actuator 112 is pulled inwardly and pulls the yoke member 154 rearwardly 
to the position shown in FIG. 11. When this occurs, the spring 157 will 
also cause the rudder 15 to move downwardly to its normal steering 
position as shown in solid line view in this figure. When the underwater 
obstacle 99 is struck, the rudder 152 may pivot upwardly about the pivot 
pin 153 and cause the spring 157 to extend. When this occurs, the pin 155 
will traverse the slot 156 and hence no force will be exerted on the yoke 
member 154. It should be noted that a fixed stop 159 may be carried by the 
rudder 151 that contacts the bracket 152 to set the down steering position 
for the rudder 151. 
If the operator desires to pivot the rudder 151 up to is non-steering 
position, the handle 113 is moved inwardly as previously described and a 
force is then exerted on the wire actuator 112 to urge it and the yoke 
member 154 outwardly from the solid line position shown in FIG. 14 to the 
phantom line view in this figure. Because the pin 155 is at the end of the 
slot 156, the rudder 151 will be pivoted upwardly to it raised position. 
When the rudder 151 in this embodiment is placed in its non-steering 
position, it will still be submerged in the body of water in which the 
watercraft is operating and hence will still create some drag. However, 
since the rudder is pivoted to the position shown in phantom line view in 
FIG. 14, the amount of this drag will be reduced and the advantages of the 
proceeding embodiment will be realized, although not to the same extent. 
It should be readily apparent from the foregoing descriptions that the 
described embodiments of the invention provide a very effective rudder 
mechanism that can be utilized in conjunction with a jet propelled 
watercraft to effect steering under low speed and coasting conditions. The 
rudder easily can pivot up to avoid damage when striking an underwater 
obstacle or inadvertently left down when beaching. The operator can easily 
move the rudder to a non-steering position so as to permit high speed 
operation without interference from the rudder. Of course, the foregoing 
descriptions is that two embodiments of the invention and various changes 
and modifications may be made without departing from the spirit and scope 
of the invention, as defined by the appended claims.