Abstract:
An outboard jet drive marine system for a boat comprises a bucket assembly adapted to be mounted to a jet drive unit for receiving a water exhaust from a jet drive unit. The bucket assembly has a bucket housing. The bucket housing has a first exhaust, and at least a second exhaust. The second exhaust directs the water jet in a direction towards and beneath the boat. The bucket housing has an entrance port for receiving said water exhaust. A bucket is rotatably mounted on the bucket housing at the first exhaust and is rotatable relative to the first exhaust between an open position and a closed position. The bucket deflects water entering the entrance port to the at least a second exhaust when in a closed position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This Application is a Non-Prov of Prov (35 USC 119(e)) application of Provisional Application No. 60/751,700 filed on Dec. 19, 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     This invention is related to an exhaust for an outboard jet propulsion engine, and in particular, a bucket for exhausting the water jet when driving the associated craft in the reverse direction.  
         [0003]     It is known in the art to utilize an outboard jet propulsion engine to drive a boat. As known from applicant&#39;s co-pending U.S. application Ser. No. 10/988,327, filed Sep. 14, 2005 entitled OUTBOARD JET DRIVE MARINE PROPULSION SYSTEM (the “327 application”) water is driven through a housing, the force of the exiting jet of water moving the boat in the forward direction. A bucket assembly is mounted at the jet exhaust so as to selectively move from a first position to a second position between covering the exhaust and keeping clear of the exhaust. As the bucket assembly covers an exiting water jet, it diverts the direction of the water jet to move the boat in the reverse direction.  
         [0004]     Making reference to  FIGS. 1A and 4A , a prior art bucket assembly generally indicated as  10  includes bucket housing  12  adapted to be mounted downstream of the water jet exhaust of the jet drive unit. A bucket  14  is rotatably mounted on bucket housing  12  so as to selectively close a first exhaust at an exit end of bucket housing  12  as seen in  FIG. 2A . As the jet exiting the jet drive unit hits upon an interior surface  16  ( FIG. 1A ) of bucket  14 , the water is blocked from exiting the first exhaust and is deflected through exhaust plenum  22  on either side of bucket  14 .  
         [0005]     Plenums  22  extend from bucket  14  and are in communication with the interior of bucket  14  on either side of bucket  14  (see  FIGS. 1A and 3A ) to also provide an escape for water deflected against interior back surface  16  of bucket  14 . The exhausts of plenum  22 , are substantially coextensive with the bucket and exhaust water in a direction generally back and towards the lower surface of housing  12  when bucket  14  is in the closed position. In this way, water is pushed back towards the boat having a net effect of pushing the boat in the reverse direction.  
         [0006]     This structure has been satisfactory for reversing the boat under the control of a jet propulsion engine. However, it suffers from the disadvantage that power is lost when the engine is required to make tight turns in the reverse direction; particularly in the type of movements required by a tugboat, i.e., tight quick turns under high power. As known from the &#39;327 application, steering of a boat utilizing the jet propulsion engine is accomplished by moving the direction of the jet, i.e., movement of the bucket and exhaust port about a pivot point  30  relative to the remainder of the housing or the boat. During tight maneuvers, one of plenums  22  became blocked by the structure of the boat, reducing the effective power of the engine. Additionally, water jets exiting plenums  22  quickly lost their cohesion and in effect their power.  
         [0007]     Furthermore, it was discovered that the gas exhaust from the engine housed within the jet propulsion housing was producing bubbles as it exited the housing, which was interfering the optimal operation of the jet engine as a result of cavitation.  
         [0008]     Accordingly, an improved bucket assembly and exhaust system is desired which overcomes the deficiencies of the prior art. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     Objects, features of the present invention will be apparent from the written description in which:  
         [0010]      FIG. 1A  is a front perspective view of a bucket assembly constructed in accordance with the prior art;  
         [0011]      FIG. 1B  is the comparable perspective view of a bucket assembly constructed in accordance with the invention;  
         [0012]      FIG. 2A  is a side elevational view of a bucket assembly constructed in accordance with the prior art;  
         [0013]      FIG. 2B  is the comparable elevational view of a bucket assembly constructed in accordance with the invention;  
         [0014]      FIG. 3A  is a front perspective view showing a prior art bucket assembly;  
         [0015]      FIG. 3B  is a comparable front perspective view of a bucket assembly constructed in accordance with the invention;  
         [0016]      FIG. 4A  is a rear elevational view of a prior art bucket assembly in the closed position;  
         [0017]      FIG. 4B  is a rear elevational view of a bucket assembly constructed in accordance with the invention in the closed position;  
         [0018]      FIG. 5  is a side elevational view of a bucket assembly mounted on a jet propulsion engine in a substantially open position constructed in accordance with the invention;  
         [0019]      FIG. 6  is a rear perspective view of the housing and bucket assembly, constructed in accordance with the invention;  
         [0020]      FIG. 7  is a side elevational view of the bucket assembly constructed in accordance with the invention in the open position;  
         [0021]      FIG. 8  is a first side elevational view of a housing and bucket assembly constructed in accordance with another embodiment of the invention;  
         [0022]      FIG. 9  is a rear elevational view of the housing and bucket assembly in the closed position constructed in accordance with the invention of  FIG. 8 ;  
         [0023]      FIG. 10  is front elevational view of a housing and bucket assembly in the closed position constructed in accordance with the invention of  FIG. 8 ;  
         [0024]      FIG. 11  is a bottom plan view of the housing and bucket assembly in the closed position constructed in accordance with the invention of  FIG. 8 ;  
         [0025]      FIG. 12  is a top plan view of the bucket assembly in the closed position constructed in accordance with the invention of  FIG. 8 ;  
         [0026]      FIG. 13  is a side elevational view of the opposite side of bucket assembly in a closed position constructed in accordance with the invention of  FIG. 8 ;  
         [0027]      FIG. 14  is a sectional view taken along line  14 - 14  of  FIG. 8 . and  
         [0028]      FIG. 15  is a first side elevational view of a housing and bucket assembly in the open position constructed in accordance with the invention of  FIG. 8 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0029]     Reference is made to  FIGS. 1B, 2B ,  3 B and  4 B in which a bucket assembly, generally indicated as  100 , is shown. Bucket assembly  100  includes a bucket housing  104 . A bucket  102  is rotatably mounted on bucket housing  104 . Bucket housing  104  is in communication with a water exhaust of the jet propulsion engine so as to receive water existing the water exhaust (not shown). Bucket housing  104  has an entrance port  106  and a first exhaust  108  ( FIG. 7 ), seen at an opposed end of housing  104  for allowing water to exit bucket housing  104  when bucket  102  is in the open position.  
         [0030]     An exhaust assembly, generally indicated as  110 , provides a second exhaust. The exhaust assembly  110  has a first vent  112  and a second vent  114 . Vent  112  extends along a first axis and vent  114  extends along a second access so that the first axis intersects the second axis, i.e. vent  114  is angled relative to vent  112 . When bucket  102  blocks water from exiting exhaust  108 , it also places vents  114 ,  112  are in communication with the interior of bucket housing  104  to allow water to exit when bucket  102  is in the closed position.  
         [0031]     A bucket linkage  124  is connected to bucket  102 . A reverse cable  126  which controls linkage  124 , rotates bucket  102  to a first position in which bucket  102  is open ( FIG. 5 ,  FIG. 6 ) to allow water to pass through exit port  108 . Linkage  124  also controls bucket  102  to move in a direction to close exit port  108  and redirect the water path through first and second vents  112 ,  114  of bucket housing  104  to guide the water in a direction substantially back towards the jet propulsion engine housing  202 .  
         [0032]     In a preferred embodiment, bucket housing  104  has a substantially circular body. Vents  112 ,  114  are disposed along the circumference of bucket housing  104 , away from a bottom  140  of bucket housing  104  and on opposed sides of a pivot axis  119  extending through bucket housing  104 .  
         [0033]     The angle formed between vent  112  and vent  114  should be sufficient to divert water at an angle to flow around a boat to which exhaust assembly  110  is attached. In a preferred non-limiting embodiment, the angle formed by the intersection of the axes along which vents  112  and  114  lie is about 34°. Accordingly, in the closed position, water enters bucket housing  104  in a direction towards bucket  102 . When in the closed position, water is deflected by bucket  102  substantially reversing direction out through first and second vents  112 ,  114 . When in the open position, water will flow directly through exit port  108  of bucket housing  104 .  
         [0034]     Bucket  102  is substantially curved so as to be convex ( FIG. 4 ) providing room for water traveling through bucket housing  104  to travel towards first and second vents  112 ,  114  as well as providing a surface which facilitates the substantially unimpeded deflection of water in the reverse direction; namely the convex curve.  
         [0035]     First and second vents  112 ,  114  are in fluid communication with each other when bucket  102  is in the closed position. Accordingly, if during tight maneuvers either one of first and second vents  112 ,  114  becomes closed against the jet unit structure, the pressure of the water exiting the unblocked vent is increased. In this way, thrust sufficient to perform the tight maneuver is maintained. In this way, the jet propulsion engine is self-adjusting.  
         [0036]     Furthermore, bucket  102  includes a first plenum  130  and a second plenum  132  in communication with the interior of bucket housing  120  to provide a third exhaust for the water jet when bucket  102  is in the closed position. Plenums  130 ,  132  preferably extend a length between extending beyond bucket  102  and to at least a bottom surface  140  of bucket housing  104  when the housing is in a closed position.  
         [0037]     Plenums  130 ,  132  substantially reside in a plane. Secondary exhausts  112 ,  114  substantially reside in a second plan, the first plane intersecting the second plane at a substantially obtuse angle. In this way, the water exiting the plenums  130 ,  132  and the secondary events avoid housing  200 .  
         [0038]     Furthermore, as the result of the longer plenum run, the jet remains more cohesive as it exits plenum  130 ,  132 . Additionally, by releasing the jet at a point at least at the bottom of bucket housing  104 , the boat and/or housing are less likely to interface with the jet thrust, increasing overall thrust.  
         [0039]     A secondary problem is cavitation that is air bubbles being trapped in the jet stream intake. The air bubbles are formed from the exhaust of the engine from the housing.  
         [0040]     Reference is now made to  FIG. 7  in which structure for diverting air bubbles in accordance with another embodiment of the invention is provided. A housing for an engine for driving the jet propulsion unit as known from U.S. application Ser. No. 10/988,327 and incorporated as if fully detailed herein, generally indicated at  200 , includes sidewalls  202 . Exhausts are formed as elongated channels  204  extending along a lower portion of sidewall  202 . Channels  204  are operatively coupled to the exhaust of the engine of the jet propulsion system. In this way, the bubbles are diverted beyond the intake of the jet propulsion drive.  
         [0041]     Reference is now made to  FIGS. 8-15  in which an alternative embodiment of the invention is provided. The primary difference between the bucket assembly shown in this embodiment and those shown in  FIGS. 1B-7 , is that the vents  112 ,  114  have been replaced by an exhaust disposed within the bottom of the housing; the exhaust including vanes for directing the water. As known from co-pending application U.S. Ser. No. 10/988,327, the bucket assembly is moved from the open to the closed position by a vertical cable  126 . However, it has been determined that in a preferred embodiment, the length of the cable, to achieve maximum result, must be relatively short given the length of the entire control assembly. In a preferred embodiment, the cable length extending in the vertical direction is about three inches. Because of this small throw distance, a bucket assembly must be designed to move the entire bucket so that the entire bucket is substantially clear of the output of the water jet when the bucket is in the open position to allow propulsion of the boat in a forward direction.  
         [0042]     Furthermore, to reduce draft on the boat, it is desirable to have a venting mechanism for the housing which is not disposed on the outside of the housing as with vents  112 ,  114 . Accordingly, this embodiment is a more streamlined embodiment which still directs water back towards the boat to create reverse thrust but angles substantially all of the exiting water jet below the boat so as not to reduce the thrust of the water jet.  
         [0043]     Reference is now had to another embodiment of the bucket assembly, generally indicated as  300  and constructed in accordance with the invention. Like structure is indicated by like numerals for ease of description. Bucket assembly  300  includes a bucket housing  304 , a bucket  302  is rotatably mounted on bucket housing  304 . Bucket housing  304  is in communication with the water exhaust of the jet propulsion engine to receive water exiting the water exhaust as described above. Bucket housing has an entrance port  106  and an exhaust  108  at an opposite end of bucket housing  304 .  
         [0044]     An exhaust assembly, generally indicated as  310  is formed with housing  304 . Exhaust assembly  310  includes an exhaust frame  314  and directional vanes  316  and  318  disposed within frame  314 . Vane  316  extends across frame  314  and is formed at an angle relative to the plane of the bottom of the boat (not shown) to form an angle of less than 90° therewith, but greater than 1° so as to direct water exiting through exhaust  310  towards the boat but below the plane in which the bottom of the boat resides. Frame  314  holds vanes  316 ,  318  in place so that the entire venting assembly  310  form a structure which is in fluid communication with the interior of housing  304 . As seen in  FIG. 14 , vanes  316 ,  318  intersect each other and form a plurality of first plenums  340 .  
         [0045]     During operation, water flows in the direction of arrow A through housing  304 . When bucket  302  is in the closed position, it deflects water in the direction of arrow B, as a result of its curved surface towards vanes  316 ,  318  ( FIG. 14 ). Because of the curved surface of bucket  302 , water traveling in the direction of arrow B does not interfere with water traveling in the direction of arrow A reducing turbulence and providing greater efficiency of thrust out of the bucket assembly in the direction substantially of arrow C back towards the boat and down. In this way, the jet stream used to propel in the reverse direction does not interfere with the boat. Additionally, water is directed to the sides of the plenum (into the page and out of the page of  FIG. 14 ) to exit through first plenum  330  and a second plenum  332 .  
         [0046]     Bucket  302  includes a second plenum and a third plenum  332  in communication with the interior of the bucket housing  304  to provide a third exhaust for the water jet when bucket  302  is in the closed position. Plenum  330 ,  332  extend to be at least coextensive with the bucket  302  but a preferred embodiment extends a distance from beyond bucket  302  to at least a bottom surface  346 , each plenum  330 ,  332  has respective exhaust opening  352 ,  354 . Furthermore, plenums  330 ,  332  are tapered towards exhaust  352 ,  354 .  
         [0047]     Like plenums  130 ,  132 , plenums  330 ,  332  are formed at an angle relative to a bottom  346  of housing  304  to direct water existing plenum exhaust  352 ,  354  towards the boat hull but down to avoid the jet from being deflected against the boat hull.  
         [0048]     It should also be well understood, as shown in  FIG. 15 , when bucket  302  is in the open position water moving in the direction of arrow A passes through exit port  108  and does not get deflected through plenum  340 . In this way, the boat is pushed in the forward direction in accordance with the invention.  
         [0049]     It should be noted that plenums  330 ,  332  are formed of an outer wall  360  of bucket assembly  302 . A front wall  362  which may be formed of a single unitary piece across the entire bucket assembly  302  or individual pieces, and an interior sidewall  364  which slides along frame  314  (however, the outer wall of frame  314  may also be used to form a wall of the plenum). It is this entire assembly which is lifted when bucket  302  is in the open position as shown in  FIG. 15 .  
         [0050]     By providing vanes within frame  314  at the exhaust, there is a greater surface area along the traveled path which focuses the water, cuts down on turbulence and increases the pressure of the exiting water. Similarly, by tapering plenums  330 ,  332 , the pressure of the water is increased as the cross section of the plenum decreases. Furthermore, the longer the plenum, the more directed and focused the water column becomes exiting in the direction of arrow D ( FIG. 14 ). Again, substantially in the direction towards, but down, relative to the boat to which the jet propulsion system is attached.  
         [0051]     Thus, while there have been shown, described and pointed out novel features of the present invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and change in the form and detail are contemplated so that the disclosed invention may be made by those skilled in the art without departing from the spirit and scope of the invention. It is the intention therefore to be limited only as indicated by the scope of the claims appended hereto. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention, which as a matter of language, might be said to fall there between.