Hydrojet Propulsion Drive

Abstract

An improved hydrojet propulsion drive is described for a propulsion drive having a pair of vertical substantially rectangular openings on either side of a rotatably mounted steering vane with means for directing the propulsion jets from said openings into the steering vane, downwardly, and forwardly for reverse drive of the craft. The water directing means includes a pair of deflection plates movable across the jet streams deflecting the stream into a reversal cup carried by and below the steering vane. Deflection ridges can be included on the deflection plates for sub-dividing the reversal jet stream. The hydrojet pump impellor and stator stages are positioned at mating ends of foreward and aftward housings secured together only by two bolts which readily permit disassembly for immediate access to the impellor and stator. The stator can be formed by slotting cup-shaped member, projecting straightening vanes through the slots to an opposed flange member and ridgedly securing the three-elements together.

Parent Case Text

BACKGROUND OF INVENTION

This application is a continuation in part of our copending U.S. Pat. application Ser. No. 108,946, filed Jan. 22, 1971, entitled Water Jet Propulsion Apparatus.

Description

Our earlier application is directed to a water jet propulsion apparatus wherein a hydrojet stream is directed out of a pumping stage into vertical substantially rectangular openings on opposite sides of a substantially vertical steering vane. Reverse drive is accomplished by moving a reversal cup normally positioned beneath the steering vane for foreward drive to a position across the jet stream for reverse drive.

Broadly stated, the present invention to be described in greater detail below, is directed to an improved hydrojet propulsion apparatus of the type generally having two vertical substantially rectangular jet stream outlet openings with a substantially vertical steering vane positioned therebetween wherein the water jet streams are directed into the steering vane and downwardly and forewardly for reverse drive of the craft.

In accordance with one embodiment of the present invention, the means for directing the water into the steering vane includes a pair of deflection plates hingedly mounted on the steering vane for movement from a position parallel to one another during foreward drive and across the propulsion streams for direction of the propulsion streams into the steering vane and downwardly into a reversal cup positioned below and carried by the steering vane.

The improved reversal system in accordance with the present invention avoids the inclusion of any members projecting rearwardly from the steering vane and particularly the movable reversal cup of our previous application identified above which could interfere with objects and by described objects that might move to a position at the aft end of the steering vane. In accordance with another aspect of the present invention, the deflection plates described above can include interleaving curved deflection ridges projecting toward one another for sub-dividing the jet stream during reverse operation and providing a smoothly curved guiding surface for a sub-divided portion of such jet stream.

In accordance with still another aspect of the present invention, the impellor and stator stages are housed in foreward and aftward housings joined together between these two stages only by two bolts accessible from the aft end of the propulsion drive. With this construction, the propulsion drive can easily be disassembled for immediate access to the impellor and stator stages which are the structures apt to be damaged or clogged during operating of the propulsion drive.

In accordance with another aspect of the present invention, a method is provided for efficiently and economically forming the stator element of the propulsion drive and wherein the stator element produced thereby can easily be inserted into or removed from the stator stage for cleaning, repair, or replacement. This method includes the steps of forming a curved surface to the stator such as by forming a cup-shaped member with the opening thereto at the inlet side of the stator, slotting the curved surface in accordance with the cross-section of the straightening vanes, projecting the straightening vanes through the slots in the surface to the element forming the other surface of the stator, and ridgedly securing the separate elements of this assembly together.

In accordance with still another embodiment of the present invention the reversal means is in the form of a pair of double walled doors hingedly supported in the steering vane and movable into place across the propulsion jet outlet for deflection of the propulsion jets into the vane, downwardly, and forwardly.

These and other features and advantages will become more apparent upon a perusal of the following specification taken in conjunction with the accompanying drawings wherein similar characters of reference refer to similar structures in each of the several views.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view, partially broken away, illustrating the present invention.

FIG. 2 is a foreshortened side elevational sectional view, partially broken away, of a portion of the structure shown in FIG. 1.

FIG. 3 is a top view, partially broken away, of the structure shown in FIG. 2.

FIG. 4 is an elevational rear view of the structure shown in FIG. 2 taken along line 4--4 in the direction of the arrows.

FIG. 5 is a schematic side elevational sectional view showing the entire inlet outline omitted by foreshortening FIG. 2.

FIG. 6 is a bottom view of the structure shown in FIG. 5 taken along line 6--6 in the direction of the arrows.

FIG. 7 is a portion of a top view showing a portion of the structure shown in FIG. 3 moved to position for reverse drive of the craft.

FIG. 8 is an elevational sectional view schematically illustrating the method of manufacturing the stator assembly.

FIG. 9 is an enlarged elevational sectional view, similar to a portion of FIG. 2, and showing another embodiment of the present invention.

FIG. 10 is a rear elevational view of the structure shown in FIG. 9 taken along line 10--10 in the direction of the arrows.

FIG. 11 is a top view, partially broken away, of the structure shown in FIGS. 9 and 10 but with the deflection plates shifted to position for reverse drive.

FIG. 12 is a cross-sectional view of a portion of the structure shown in FIG. 10 taken along line 12--12 in the direction of the arrows.

Referring now to the drawing, there is shown a watercraft 11 having a hull 12, typically made of fiberglass, and having a prime mover 13, here illustrated as an internal combustion engine, connected via a drive shaft 14 to a pump 15 in the water jet propulsion system 16. The propulsion system includes a water conveying conduit 17 for carrying water from an inlet opening 18 flush with the bottom of the hull 12, through the pump 15 and out an outlet opening 19 as a high velocity jet stream for propelling the craft.

A steering and reversing mechanism 21 is provided for manipulating the jet stream at the outlet opening 19 for steering and reversing the craft.

Referring now to FIG. 2, the inlet 18 includes an initial conduit portion 38, such as of fiberglass and formed when the boat is molded, and this conduit portion is connected, such as by screws 32, to a cast housing 33, such as of aluminum, for the impeller portion of the pump 15 and forming the remainder of the conduit 17. The lower end of housing 33 defines the aft end 37 of the inlet opening 18 and also includes a flange 34 engaging the hull at one edge of the inlet opening 18,

A plurality of rearwardly downwardly angled, thin, guard vanes 43 are connected to the wall of the conduit 17 adjacent the inlet opening 18 and extending across the conduit to prevent debris and large objects from entering the inlet opening. These vanes are aerodynamically tapered in the direction of water flow so as not to disrupt flow of water in conduit 17.

The main housing 33 of the conduit 17 includes a spherical surface portion 45 positioned within a circular opening 46 in the transom 47 of the craft, and a ring 48 having an opening with a diameter slightly larger than the spherical surface portion 45 is bolted to the transom and provided with a sealing gasket 49 creating a seal with the spherical surface 45.

A shaft housing 51 is provided in the main housing 33 extending into the conduit and supported by a narrow septum 52 extending almost to the pump impellor for completely enclosing the drive shaft 14 up to connection to the impellor of the pump. The drive shaft 14 is mounted in the shaft housing 51 in sealed bearings 53. A packing gland 54 is provided at the inner end of the housing adjacent the end of the drive shaft, and seal draining channel 55 drains any leakage to the bilge.

The pump impellor 61 mounted on the end of the drive shaft with a lock nut 58 is provided with a hub 62 having an outwardly flared surface 63 in the downstream direction with a plurality of blades 64 extending outwardly from the flared surface 63 to an outer hollow cylindrical support member or shroud 65. From the inlet side of the impellor 61 to the outlet thereof, the flared surface 63, the blades 64 and the support member 65 define a plurality of fluid passageways 66 having a constant outside diameter but an increasing inside diameter.

A stator and steering support housing 71 is secured to the main housing at the aft end thereof around the impellor by two bolts 70. This housing 71 includes a generally cup-shaped cavity 71' terminating in an outlet manifold 77 at the aft end defined by outside substantially vertical side walls 78 and 79 and top and bottom walls 81 and 82. A central substantially vertical dividing member 83 divides the outlet manifold 77 into two vertically oriented, substantially rectangular outlet openings 84 and 85 bounded inwardly by dividing member 83, outwardly by outside side walls 78 and 79 and at the top and bottom by walls 81 and 82.

A stator assembly 72 is provided for insertion into the cavity 71' for straightening the jet stream between the impellor 61 and the outlet openings 84 and 85. This stator assembly includes a cup-shaped member 73 with its large open end centered within and spaced inwardly from an angled annular flange member 74 with a plurality of straightening blades 75 projecting through the cup member 73 and secured to the flange 74. This stator assembly is inserted into the cup-shaped cavity 71' in support housing 71 with the annular flange member 74 seated in an annular recess 76 at the end of the support housing 71 immediately adjacent to the impellor section.

The annular space between the cup-shaped member 73 and the annular flange 74 corresponds with and faces the annular outlet of the impellor section so that the propulsion stream from the impellor section is carried into the space between the cup-shaped member 73 and the flange member 74 where it is straightened out and directed longitudinally to the outlet openings 84 and 85.

A steering slab or vane 86 is rotatably supported vertically at the end of the outlet housing 77 via a pin 87 rotated by means of an actuating arm 88 positioned above the top wall 81. A control cable 89 is connected to the actuating arm 88 and passes through the housings 71 and 33 to the controls inside the hull for turning the steering vane to turn the craft. With this cable and another reverse control cable, to be described below, passing through the housings 71 and 33 there is but a single circular opening in the transom for passing the drive assembly and all the controls therefore.

The side walls 78 and 79 converge toward the steering vane 86 to converge the jet rearwardly and slightly toward the steering vane 86.

With the impellor stage of the pump including impellor 61 is carried in the foreward housing 33 and the stator stage including stator assembly 72 carried in the rearward housing 71, housings 33 and 71 are connected together at an annular flange joint 90 having only a pair of bolts 70 accessable from the aft end of the housing (see FIG. 4). By removal of bolts 70 (including disconnection of the steering and reversing mechanisms to be described below) housings 31 and 71 can be separated respectively exposing the impellor 61 and the stator assembly 72 for easy cleaning or repair. The impellor 61 can easily be removed by unscrewing nut 58. With the stator assembly 72 formed as a sub-assembly inserted in aftward housing 71, the stator assembly can easily be dropped out and replaced.

The reversal mechanism 21 for reversing the propulsion stream to stop or drive the craft backwards is carried by the steering vane 86 and includes a horizontally extending top support bar 86' (see FIGS. 3 and 7) with a downwardly extending rear bar 86" at the aft end, a pair of deflection plates or walls 91 and 92 hingedly supported at the aft end of the steering vane 86 via a hinge pin 93 through portions of rear bar 86 and a reversal cup member 94 secured on rear bar 86" on the bottom of the vane 86.

The deflection plates 91 and 92 which in normal forward drive mode are flat against the sides of steering vane 86 are provided with interdigital protruding portions 91' and 92' respectively which are rotatably mounted on the hinge pin 93 at the aft end of the steering vane 86.

Cam surfaces 95 and 96 are positioned on the outside surface of the plates 91 and 92 respectively substantially halfway between the top and bottom thereof adjacent the forward edge on the side immediately adjacent the outlet opening. Cam members 97 and 98 are rotatably mounted in a notch in side walls 78 and 79, respectively, for engaging the cam surfaces 95 and 96, respectively, to hold the deflection plates 91 and 92 in desired operating position. The cam members 97 and 98 are rotatably controlled by shafts 97' and 98', respectively, which extend upwardly within the respective side wall 78 and 79 to a reversal control mechanism 99.

The control mechanism 99 includes a pair of actuating arms 101 and 102, respectively, ridgedly connected on the upper ends of shafts 97' and 98', respectively, and which in turn are rotatably connected by pins 101' and 102' via latching arms 103 and 104 to a cross arm 105 secured on a control post 106 movable fore and aft by the operator's controls for full forward and full reverse jet drive, respectively.

The deflection plates 91 and 92 include interleaving curved deflection ridges 111 and 112, respectively, projecting across the vane to adjacent the other plate when the plates are parallel with the vane. These deflection ridges 111 and 112 curve from a position between the top and bottom of the vane at the foreward end of the plates 91 and 92 to a position between the fore and aft ends of the steering vane 86 at the bottom of the plates.

The reversal cup 94 formed by a bottom wall 113 and side walls 114 and 115 includes a deflection ridge 116 curved from a position adjacent the lower rearward end of deflection ridges 111 and 112 to a position between the top and bottom of the reversal cup 94 at the foreward end thereof. While a single deflection ridge has been shown for each of the deflection plates and the reversal cup member dividing the propulsion jet stream substantially in half during reverse drive, additional deflection ridges can be provided to further subdivide the jet stream.

During the foreward drive of the watercraft the deflection plates 91 and 92 are held parallel to one another against the sides of the steering vane 86, and the propulsion jet streams are directed rearwardly partially against the sides of the vane. Movement of the steering vane 86 will cause the jet streams to move from one side to the other, moving the boat in the direction desired.

The reversal of the watercraft control shaft 106 is moved rearward thereby moving cam members 97 and 98 from a position across the jet stream to a position parallel with the jet stream thereby permitting deflection plates 91 and 92 to move under the force of the jet stream outwardly across the jet streams, thereby directing the jet streams of the steering vane and the reversal cup 94. A portion of the combined jet streams is carried by the deflection ridges 111 and 112 to the deflection ridge 116 of the reversal cup and the other portion of the stream is carried by the back surface of the vane to the portion of the reversal cup beneath deflection ridge 116, both portions of the jet stream emanating from the reversal cup forewardly of the craft. It will be appreciated that with the reversal cup carried by the steering vane, steering of the watercraft will continue to be accomplished during reverse drive.

The stator assembly 72 is formed by slotting the cup-shaped member 73 with slots curved to the cross-section of the steering vanes 75 which are then projected through the slots to the annular flange member 74. The assembly of cup-shaped member 73, vane 75, and flange member 74 are then secured together. Conveniently, these members can be initially tack welded together and then placed together in a blazing furnace.

While the cam surfaces and cam members have been described and illustrated as located at the mid portion of the deflection plates, it will be appreciated that the deflection plates actuation means can be located elsewhere, such as at the top or at the bottom of the deflection plates.

Referring now to FIGS. 9-11, there is shown another embodiment of the present invention wherein the deflection plates for reverse drive form a part of double walled doors which receive the propulsion streams therewithin for direction downwardly and forwardly. The steering vane assembly 121 is rotatably positioned vertically between the vertical outlet openings 84' and 85' on upper and lower support posts 122 and 123 and includes a pair of doors 126 and 127. Each door includes a deflection plate wall 131 on the side of the door closest to the propulsion jet and an inner door wall 132. Each door is rotatably supported on a vertical rod 133 at the aft end of the steering vane assembly 121 so that when the doors are closed the inner walls 132 are adjacent to one another and when the doors are swung outwardly at their forward end the opening between the walls 131 and 132 of each door is aligned with one of the jet stream outlet openings for receiving the stream. Interiorally of each door, a deflection ridge 134 is provided with the leading edge substantially midway of the height of the door and curving downwardly and then forwardly to deflect the lower portion of the jetstream downwardly and forwardly. Also, the aft interior of each door is provided with a curved surface 135 extending from the top of the door downwardly and then forwardly to deflect the upper portion of the streem downwardly and forwardly.

The actuating means for the steering vane and deflection doors are located on top of the steering assembly and include an actuation arm 124 operable by a control cable or rod 125 for turning the steering vane from side to side.

The deflection doors 126 and 127 are provided at their tops with upwardly projecting posts 141 and 142 secured thereto, such as by screw threads, the surfaces of which serve as cam surfaces in arcuate slots 143 and 144 of a cam member 145. The forward ends of the slots 143 and 144 are spaced apart a distance to hold the posts 141 and 142, and therefore the doors 126 and 127 apart to align the openings at the forward end of the doors with the propulsion outlet openings, and the openings 143 and 144 curve toward one another aftward so that the aft ends are spaced apart a distance for holding the posts 141 and 142 closer together to close the doors into the vane and bring the inner walls 132 together at their forward ends.

The cam member 145 is slidably supported on a shaft 146 the aft end of which is mounted by a bracket 147 at the aft end of the vane 121 and the forward end of which is positioned within a bore through the upper support post 123 for the steering vane. This cam member 145 is moved forward and aft by an actuating arm 152, the aft end of which is connected by a pin 151 to the cam member 145 and the forward end of which is connected to a control cable or rod 153 by means of a pivot pin 154.

As shown in FIG. 12 the sidewalls at the outlet end of the propulsion unit have relief slots 161 substantially the full height thereof with the aft surface 162 of these slots curved forwardly so that any water forced out of the slots 161 is directed forwardly of the jet propulsion drive in the direction indicated by the arrow in FIG. 12.

As shown in FIGS. 9 and 10, a web portion 163 extends from the fore end to the aft end of the steering vane for rotational support of the doors 126 and 127 at the aft end. This web portion 163 extends downwardly between the two doors for inclusion of a lower extending rudder on the bottom thereof if such is desired in any environmental use of the propulsion drive.

The doors 126 and 127 provide balanced elements for reverse drive and reverse steering which can be operated very easily and with little effort even with a high thrust propulsion stream exiting from the outlet openings 84' and 85'. Where a single deflection plate is utilized on each side of the vane, a portion of the jet stream from each deflection plate is deflected across the vane against the other deflection plate making it more difficult to return the deflection plates to the position parallel to the sides of the steering vane.

The use of the relief slots 161 permits sideward and forward direction of excess jet stream where the door has been deflected across the outlet propulsion opening and cannot accommodate the full thrust that otherwise would exit out of the vertical opening. This has been found especially advantageous where the doors are moved to the reverse position covering the outlet openings and the steering vane turned to one side whereby one of the doors is canted outward from the opening associated therewith and the other door is canted across the outlet opening associated therewith. In the case of the latter door, a greater amount of water is forced out of the relief slot 161, and it has been found that this aids in turning the craft under these circumstances.

Claims

We claim:

1. In a water jet propulsion apparatus for watercraft including a water conveying conduit extending from an inlet at the bottom of the hull to an outlet at the aft end of the craft and a pump within said conduit for discharging water as a propulsion jet past a vertical steering vane rotatable about a vertical axis, the improvement comprising said steering vane being hollow and having spaced apart walls defining a hollow interior closed off from the propulsion jet during forward drive of the craft and means for directing water from said propulsion jet into the interior of said vane and downwardly and forwardly for reverse drive of said craft.

2. The structure in accordance to claim 1 wherein said directing means includes

at least one movable deflection plate forming at least a part of one of said walls,

means for mounting said deflection plate on said steering vane with said plate rotatable about a vertical axis from a position against said vane closing off the interior of said

vane to a position at least partially projecting into and intercepting at least part of said propulsion jet, and

means for moving said plate at least partially into said propulsion jet to deflect at least part of the propulsion jet into the interior of said vane for downward and forward direction therein.

3. In a water jet propulsion apparatus including a water conveying conduit for conveying water from an inlet at the bottom of a craft hull to an outlet at the aft end of the craft, a pump within said conduit for discharging water as a propulsion jet through said outlet, said outlet formed as two vertical substantially rectangular openings and a substantially vertical steering vane rotatably mounted about a vertical axis between said rectangular openings the improvement comprising:

said steering vane being hollow and having spaced apart walls defining a hollow interior closed off from the propulsion jet during the forward drive of the craft and

means for directing water from said propulsion jet at both of said rectangular openings into the interior of said vane and downwardly and forwardly for reverse drive of said craft.

4. In the apparatus in accordance with claim 3

a pair of deflection plates,

means for mounting the deflection plates in the walls on opposite sides of said steering vane with each of said plates rotatable about a vertical axis from a position with the deflection plate leading edge against said vane out of the propulsion jet and closing off the interior of said vane to a position at least partially projecting into said propulsion jet opening up the interior of said vane to the propulsion stream, and

means for moving said plates to a position with the deflection plate leading edge at least partially across said rectangular openings and at least partially intercepting the propulsion jet to divert the propulsion jet into the interior of said vane and downwardly and forwardly for reverse drive of the craft.

5. In the apparatus in accordance with claim 4 jet reversal cup means mounted on and below said steering vane and movable therewith for directing the jet stream backward when said deflection plates are moved across said rectangular openings.

6. In the apparatus in accordance with claim 4 wherein said mounting means includes hinged mounting means for hingedly mounting each of said deflection plates from the aft end of said steering vane whereby the leading end of each of said plates remote from the hinged mounting to said vane swings from a position out of said propulsion jet and

closing off the interior of said vane on one side of one of said rectangular openings to a position on the opposite side of said opening diverting the propulsion jet into said vane.

7. In the apparatus in accordance with claim 6 interleaving deflection ridges on said deflection plates, each ridge extending from the plate across the vane to adjacent the other plate when said plates are parallel with said vane and curved from a position between the top and bottom of said vane at the forward end of said plate to a position between the fore and aft ends of said steering vane at the bottom of said plate.

8. In the apparatus in accordance with claim 7 jet reversal cup means mounted on and below said steeing vane movable therewith for directing the jet stream forwardly of the craft when said deflection plates are moved across said rectangular openings and a deflection ridge in said reversal cup means curved from a position between the fore and aft ends of said steering vane adjacent one end of the deflection ridges on said deflection plates to a position between the top and bottom of said reversal cup means at the forward end thereof whereby when said vanes are in a position across said rectangular openings a portion of the propulsion jet is curved downwardly to the reversal cup means by said deflection ridges on said deflection plate and then curved forwardly of the craft by said deflection ridge on said reversal cup means for reverse drive of the craft.

9. In the apparatus in accordance with claim 6, said directing means including a pair of hollow doors, said deflection plates forming the outside surface of said doors and an interior wall member forming a wall surface opposite said deflection plate for each of said doors.

10. In the apparatus of claim 9, a vertical relief slot in an outer sidewall of a housing for said outlet adjacent the rectangular openings and having a surface at the aft end thereof curved to deflect water outwardly and forwardly of the craft.

11. In the apparatus of claim 6, a cam surface and a cam member for moving said deflection plates between said position closing off the interior of said vane and said position on the opposite side of said opening.

12. In the apparatus of claim 11, said cam surface and said cam member including a post projecting upwardly on top of each of said deflection plates and a member slidable fore and aft provided with arcuate slots receiving said posts on said deflection members whereby sliding movement of said slidable member fore and aft moves said deflection plates between said position out of said jet and said position on the opposite side of said opening.

13. In the apparatus in accordance with claim 11 a cam surface on each of said deflection plates on the side closest to the rectangular opening and a cam member movable against each of said cam surfaces for moving the ends of said plates remote from the hinged mounting to the vane from positions on the outer side of said openings to positions parallel with said vane.

14. The apparatus in accordance with claim 3 wherein said pump

includes an impellor stage and a stator stage,

the inlet portion of said conduit and said impellor stage of said pump supported in a forward housing and

the outlet portion of said conduit and said stator stage of said pump supported in an aftward housing,

said forward and said aftward housings being connected together by only a pair of bolts.

15. The water jet propulsion apparatus in accordance with claim 3

includes an impellor stage and a stator stage,

the inlet portion of said conduit and said impellor stage of said pump supported in a forward housing and

the outlet portion of said conduit and said stator stage of said pump supported in an aftward housing,

said aftward housing including a cup-shaped cavity communicating with said outlet openings,

said stator stage including

a cup-shaped member with its large open end centered within the forward end of said aftward housing,

an angled, annular flange member spaced outwardly from the open end of said cup-shaped member, and

a plurality of straightening blades projecting through the cup-shaped member to said flange member and secured to said cup-shaped member and said flange member.

16. A hydrojet propulsion apparatus for watercraft comprising

a water conveying conduit for conveying water from an inlet at the bottom of the craft hull to an outlet at the aft end of the craft,

a pump within said conduit for discharging water as a propulsion jet through said outlet,

said outlet formed as two vertical substantially rectangular openings,

a substantially vertical steering vane having walls defining a hollow interior therein,

means for rotatably mounting said vane between said rectangular openings, and

means for directing water from the propulsion jet at both of said openings into the interior of said vane and forwardly for reverse drive of said craft.

17. The apparatus in accordance with claim 16 wherein said water directing means includes

a pair of deflection plates,

means for mounting the deflection plates at said walls on opposite sides of said steering vane with each of said plates rotatable about a vertical axis from a position against said vane closing off the interior of said vane to a position at least partially projecting into said propulsion jet, and

means for moving said plates at least partially into the propulsion jets from said rectangular openings for diverting the propulsion jet into the interior of said vane and downwardly and forwardly for reverse drive of the craft.

18. The apparatus in accordance with claim 17 wherein said mounting means includes means for interdigitally hingedly mounting said deflection plates from the aft end of said steering vane whereby the end of each of said plates remote from the hinged mounting to the vane swings from a position parallel with said vane adjacent one side of the propulsion jet stream immediately adjacent thereto to a position on the opposite side of such jet stream.

19. The apparatus in accordance with claim 18 wherein

said deflection plates include interleaving deflection ridges, each deflection ridge extending from the plate across the vane to a position adjacent the other plate when the plates are parallel with said vane and curved from a position substantially midway between the top and bottom of said vane at the forward end of said plate to a position substantially midway between the fore and aft ends of said steering vane at the bottom of said plate.

20. The apparatus in accordance with claim 19 including

jet reversal cup means mounted on and below said steering vane and movable therewith for passing the jet stream forwardly of the craft when deflection plates are moved across the jet stream

a deflection ridge on said deflection cup curved from a position substantially midway between the fore and aft ends of said steering vane adjacent one end of the deflection ridges on said deflection plates to a position substantially midway between the top and bottom of said reversal cup means at the forward end thereof

whereby when said vanes are in a position across the jet stream a portion of the propulsion jet is curved downwardly to the reversal cup means by said deflection ridges on said deflection plate and then curved forwardly of the craft by said deflection ridge on said reversal cup means for reverse drive of said craft.

21. In the apparatus in accordance with claim 17, said directing means including a pair of hollow doors, said deflection plates forming the outside surface of said doors and an interior wall member forming a wall surface opposite said deflection plate for each of said doors.

22. In the apparatus of claim 21, a vertical relief slot in an outer sidewall of a housing for said outlet adjacent the rectangular openings and having a surface at the aft end thereof curved to deflect water outwardly and forwardly of the craft.

23. In the apparatus of claim 17, a cam surface and a cam member for moving said deflection plates between said position against said vane and said position partially projecting into said propulsion jet.

24. A watercraft comprising

a hull including a bottom having an opening therein and a transom having an opening therein,

a propulsion means driven from within the hull including

a water conveying conduit for conveying water from an inlet opening of the bottom of the craft to an outlet to and through the opening in the transom,

a pump within said conduit for discharging water as a propulsion jet through said outlet,

said outlet formed as two vertical substantially rectangular openings,

a substantially vertical steering vane rotatably mounted between said rectangular openings and having spaced apart walls defining a hollow interior closed off from the propulsion jet during forward drive of the craft, and

means for directing water from said propulsion jet at both sides of said rectangular openings into the interior of said vane and downwardly and forwardly of the craft for reverse drive of the craft.

25. A water jet propulsion apparatus for a watercraft comprising

a water conveying conduit for conveying water from an inlet at the bottom of the craft to an outlet at the aft end of the craft,

a pump within said conduit for discharging water as a propulsion jet through said outlet and including an impellor stage and a stator stage,

the inlet portion of said conduit and said pump impellor stage formed in a forward housing and

the outlet portion of said conduit and said pump stator stage formed within an aftward housing

said stator stage including

a cup-shaped member having its open end centered within the forward end of said aftward housing,

an angled annular flange member spaced outwardly from the open end of said cup-shaped member, and

a plurality of straightening vanes projecting through said cup member to said flange member and secured to said members,

a pair of bolts for detachably connecting said forward and aftward housings,

said outlet formed in said aftward housing as to vertical substantially rectangular openings,

a substantially vertical steering vane rotatably mounted between said rectangular openings,

a pair of deflection plates,

means for interdigitally hingedly mounting said deflection plates from the aft end of said steering vane whereby the end of each of said plates remote from said hinged mounting means swings from a position parallel with said vane on one side of the rectangular opening adjacent to a position on the opposite side of said opening,

said deflection plates including interleaving deflection ridges extending from the plate across the vane to adjacent the other plate when said plates are parallel with said vane and curved from a position between the top and bottom of said vane at the foreward end of said plates to a position between the fore and aft ends of said steering vane at the bottom of said plate,

jet reversal cup means mounted on and below said steering vane movable therewith for directing the jet stream forwardly of the craft when said deflection plates are moved across said rectangular openings whereby the end of each of said plates remote from said hinged mounting means swings from a position parallel with said vane on one side of the rectangular opening adjacent to a position on the opposite side of said opening,

said deflection plates including interleaving deflection ridges extending from the plate across the vane to adjacent the other plate when said plates are parallel with said vane and curved from a position between the top and bottom of said vane at the forward end of said plates to a position between the fore and aft ends of said steering vane at the bottom of said plate,

jet reversal cup means mounted on and below said steering vane movable therewith for directing the jet stream forwardly of the craft when said deflection plates are moved across said rectangular openings,

a deflection ridge in said reversal cup means curved from a position between the fore and aft ends of said steering vane adjacent one end of the deflection ridges on said deflection plates to a position between the top and bottom of said reversal cup means at the forward end thereof,

a cam surface on each of said deflection plates on the side closest to the adjacent rectangular opening,

a cam member movable against each of said cam surfaces for moving the ends of said deflection plates remote from the hinged mounting from positions on the outer side of said openings to positions parallel with said vane, and

means for moving said cam members to divert the propulsion jet into said vane and said reversal cup means for reverse drive of the craft.

26. A water jet propulsion apparatus for a watercraft comprising

a water conveying conduit for conveying water from an inlet at the bottom of the craft to an outlet at the aft end of the craft,

a pump within said conduit for discharging water as a propulsion jet through said outlet and including an impellor stage and a stator stage,

the inlet portion of said conduit and said pump stator stage formed within an aftward housing,

said stator stage including

a cup-shaped member having its open end centered within the forward end of said aftward housing,

an angled annular flange member spaced outwardly from the open end of said cup-shaped member, and

a plurality of straightening vanes projecting through said cup member to said flange member and secured to said members

a pair of bolts for detachably connecting said aftward housing to a forward housing,

said outlet formed in said aftward housing as two vertical substantially rectangular openings,

a substantially vertical steering vane rotatably mounted between said rectangular openings and having spaced apart walls

defining a hollow interior closed off from the propulsion jet during forward drive of the craft,

a pair of deflection plates,

means for hingedly mounting said deflection plates from the aft end of said steering vane whereby each of said plates remote from said hinged mounting means swings from a position parallel with said vane on one side of the rectangular opening to a position on the opposite side of said opening to direct the jet into the interior of the vane,

means associated with said deflection plates for directing the jet stream downwardly and forwardly in the interior of said vane, and

means for moving said deflection plates between a position parallel with the sides of said vane and a position across said outlet opening.

27. A water jet propulsion apparatus for water craft comprising:

a water conveying conduit having an inlet opening substantially flush with the bottom of the craft and an outlet opening at the aft end of the craft

a pump within said conduit for discharging water as a propulsion jet through said outlet opening,

said outlet opening formed as two vertical rectangular openings defined by an outlet manifold having

a pair of outside vertical side walls,

a top wall,

a bottom wall, and

a substantially vertical central dividing member,

a unitary substantially vertical hollow steering vane, means for rotatably mounting said vane at the aft end of said dividing member between said two rectangular openings,

means for moving said vane from side to side across said openings to steer the craft from side to side and means mounted on said steering vane for directing the propulsion jet downwardly and forwardly for reverse drive of the water craft.

28. The apparatus in accordance with claim 27 wherein said outside side walls converge aftwardly toward said central dividing member.