Ships – Steering mechanism – Rudders
Reexamination Certificate
2000-09-14
2001-10-16
Swinehart, Ed (Department: 3617)
Ships
Steering mechanism
Rudders
C440S043000
Reexamination Certificate
active
06302047
ABSTRACT:
FIELD OF THE INVENTION
The invention relates in general to personal watercraft, such as jet skis and the like. More particularly, the invention relates to a retractable rudder assembly for use with personal watercraft for steering the watercraft in a throttle-off position.
BACKGROUND OF THE INVENTION
The use of personal watercraft has grown widely, and particularly the use of water jet powered watercraft, such that on any given weekend a great number of personal watercraft, to include jet skis, jet-boats and runabouts can be found in use. Each of these watercraft features a hull with a water jet drive assembly housed therein. In known fashion, the water jet drive assembly is powered by an engine operably connected to a twist grip or trigger-type throttle similar in function and appearance to that used in a motorcycle or an ATV, for example. The throttle is grasped by the hand of the watercraft operator and twisted or squeezed into a “throttle-on” position in which the engine is powered to the desired level or speed. The engine is operably coupled to a pump or an impeller for creating a pressurized water jet in the throttle-on position, the water jet being directed outwardly and away from the hull by a water jet nozzle pivotally supported on the hull of the watercraft. The water jet thus propels the watercraft in the throttle-on position. In the “throttle-off” position the engine is reduced to idle speed and the watercraft is not otherwise propelled by the water jet drive.
The water jet nozzle has two functions, the first of which, as described above, is to focus or direct the water jet in the throttle-on position in a direction away from the watercraft for propelling the watercraft. The second function of the nozzle is to steer the watercraft in the throttle-on position. If the operator falls off the watercraft during use, the throttle will automatically return to the throttle-off position and will reduce the engine speed to idle or turn the engine off. As personal watercraft are steered by the water jet as it passed through the water jet nozzle, however, if the water jet drive is throttled off it can become difficult to steer the watercraft in that these types of watercraft are not typically provided with separate rudders attached to any kind of steering device. When this occurs, therefore, it becomes difficult to efficiently, and at times safely, steer the watercraft, if at all, in the throttle-off position.
A common scenario in which this problem occurs is when a person riding a jet ski, for example, suddenly throttles-off in order to avoid colliding with another watercraft, a dock, the shore line, and/or a swimmer. The natural tendency when such an event occurs is to reduce the speed of the watercraft by throttling-off and attempting to steer the watercraft around the obstacle. If, however, the throttle of a typical personal watercraft is reduced to the throttle-off position, the operator of the watercraft suddenly loses the ability to efficiently steer the watercraft due to the loss of the dual purpose propulsion and steering water jet, and a collision may thus become inevitable as the watercraft, which is still moving at speed due to its momentum, cannot be safely steered without the water jet being passed through the nozzle of the drive assembly.
An auxiliary rudder for a jet propulsion unit is disclosed in U.S. Pat. No. 3,982,494 to Posti, which discloses a rudder moved by a hydraulic cylinder powered by a hydraulic pump and moved into a retracted position when the watercraft is operated, i.e., when it moves or is propelled at speed. The rudder assembly is constructed such that when the watercraft is moving at a sufficiently high speed a sufficient amount of water pressure is generated to supply the pump used to power the hydraulic cylinder. At speed, therefore, the pump and cylinder move the rudder into an inoperative position. If, however, the throttle is suddenly moved into a throttle-off position, for example when trying to avoid an obstacle, the watercraft will continue at speed in that it will not immediately stop. Accordingly, as sufficient water pressure still exists to keep the cylinder pumped up, the rudder will not drop down until the speed of the watercraft diminishes to the point that the water pressure is insufficient to pump the hydraulic cylinder at a force sufficient to keep the rudder in its inoperative position. Thus the rudder will only be allowed to fall into its operative position at slow speeds. By the time the rudder may be lowered, however, it may too late in that the operator of the watercraft may have already struck or passed over the obstacle prior to losing enough speed to avoid the collision.
Another rudder assembly is disclosed in the abstract of Japanese Patent Application No. 64-103253 of Kobayashi, which illustrates a rudder that is displaced upwardly when the boat strikes or runs over a shoal. The rudder is also moved upwardly into a retracted or inoperative position by the water pressure of the boat moving at a high speed, whether or not the boat is actually being propelled at that time. Again, therefore, in a throttle-off position in which there is a time lag between the throttling-off of the water jet drive and the time the watercraft loses enough speed (water pressure) to allow the rudder to extend into an operative position, the possibility exists that the obstruction which the operator of the watercraft is seeking to avoid may be struck.
What is needed, therefore, but seemingly unavailable in the art, is a retractable rudder assembly for use with a personal watercraft that will not interfere with the operation of the watercraft at a throttle-on position when the watercraft is moving at speed, but which will reliably and quickly extend downwardly into an operative position when the throttle of the drive assembly is moved into the throttle-off position, regardless of the boat speed, so that the operator of the personal watercraft retains the ability to steer the watercraft when the water jet drive is not otherwise propelling the watercraft.
SUMMARY OF THE INVENTION
The present invention provides a unique retractable rudder assembly for use with a personal watercraft which overcomes some of the design deficiencies of the known art. The retractable rudder assembly of this invention provides a simple and efficient device which allows the operator of a personal watercraft to steer the watercraft at the throttle-off position of the water jet drive assembly. The rudder assembly of this invention, when contrasted with the known rudder assemblies, seeks to provide a greater degree of reliability, durability, safety, and ease of use in addressing the problems of efficiently and safely steering a water jet powered personal watercraft in the throttle-off position.
The watercraft will have a water jet drive assembly for propelling the watercraft that includes a throttle with progressive throttle-on and throttle-off positions, and a steerable water jet nozzle through which a pressurized water jet is passed by the water jet drive at the throttle-on position(s). The rudder assembly includes a planar rudder affixed to an elongate shaft. The shaft may be either tubular or solid, as preferred. The shaft is rotatably mounted on the water jet nozzle. The rudder is biased into a normally extended position in which the rudder extends in a downward direction away from the water jet drive nozzle for use in steering the watercraft at the throttle-off position. The rudder also has a retracted position in which it is moved toward the water jet drive nozzle when the water jet drive is propelling the watercraft for minimizing the possibility of damaging the rudder at speed, striking an object therewith, and/or injuring a person with the rudder should the watercraft pass close by.
The rudder assembly also includes a paddle affixed to the above-described shaft, the paddle being positioned within a water jet flow path defined within the nozzle so that the force of the water jet at the throttle-on position striking the paddle urges the rudder into its retracted
Needle & Rosenberg P.C.
Swinehart Ed
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