CA2044349A1 - Water drawing and guiding device for jet-propelled gliding boats - Google Patents
Water drawing and guiding device for jet-propelled gliding boatsInfo
- Publication number
- CA2044349A1 CA2044349A1 CA 2044349 CA2044349A CA2044349A1 CA 2044349 A1 CA2044349 A1 CA 2044349A1 CA 2044349 CA2044349 CA 2044349 CA 2044349 A CA2044349 A CA 2044349A CA 2044349 A1 CA2044349 A1 CA 2044349A1
- Authority
- CA
- Canada
- Prior art keywords
- water
- boat body
- water intake
- guiding device
- flow regulating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B3/00—Hulls characterised by their structure or component parts
- B63B3/14—Hull parts
- B63B3/66—Gratings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B13/00—Conduits for emptying or ballasting; Self-bailing equipment; Scuppers
- B63B13/02—Ports for passing water through vessels' sides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H11/00—Marine propulsion by water jets
- B63H11/01—Marine propulsion by water jets having means to prevent foreign material from clogging fluid passage way
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- Ocean & Marine Engineering (AREA)
- Barrages (AREA)
- Toys (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The present invention relates to a water drawing and guiding device for jet-propelled gliding boats, wherein a scope gate for preventing entry of floating obstacles is attached to a water intake port formed in the bottom surface of the boat body, and the water drawn from the water intake port is accelerated by an impeller housed in a water intake duct and spouted rearwardly of the boat body, the water drawing and guiding device being characterized in that:
the scope gate is made of elastic transparent or translucent engineering plastic material into the form of a longitudinally elongated rectangle having a pair of attacking seats and a pair of flow regulating vertical walls, the arrangement being such that during the turning of the boat body, the flow regulating vertical walls flex to and fro like plate springs, the main object thereof being to provide an extremely smooth fellable water drawing action without excessively holding back natural water flow moving from the water intake port to the water intake duct or without agitating water to the extent of bubbling or decreasing the flow rate of water, thereby preventing cavitation from taking place in the water intake duct.
The present invention relates to a water drawing and guiding device for jet-propelled gliding boats, wherein a scope gate for preventing entry of floating obstacles is attached to a water intake port formed in the bottom surface of the boat body, and the water drawn from the water intake port is accelerated by an impeller housed in a water intake duct and spouted rearwardly of the boat body, the water drawing and guiding device being characterized in that:
the scope gate is made of elastic transparent or translucent engineering plastic material into the form of a longitudinally elongated rectangle having a pair of attacking seats and a pair of flow regulating vertical walls, the arrangement being such that during the turning of the boat body, the flow regulating vertical walls flex to and fro like plate springs, the main object thereof being to provide an extremely smooth fellable water drawing action without excessively holding back natural water flow moving from the water intake port to the water intake duct or without agitating water to the extent of bubbling or decreasing the flow rate of water, thereby preventing cavitation from taking place in the water intake duct.
Description
20~43~9 SPECIFICATION
WATER DRA'~ING AND GUIDING DEVICE
FOl~ Jl~`'r~ OPl~,I,I,~I~ GL,IDIIlG ~OATS
BACKGROUND OF THE INVENTION
Small-sized gliding boats of the jet-propelled type arranged for a single person to ride in a standing posture or some persons to ride in a seated posture have incorporated therein a jet-propelllng device (or water jet pump) adapted to be driven for rotation by an engine mounted on the boat.
Such jet propelling device is designed to draw water through a water intake port formed in the bottom surface of the boat body, accelerating said water by~an impeller installed in a water intake duct (or pump case) to spout it rearwardly of the boat body, the reaction force serving as the propelling force for the boat body. Thus, the jet propelllng device has the danger of drawing not only water but also garbage, seaweed, fishing lines and other various floating obstacles. Therefore, to prevent entry of suc~l obstacles, a special lattice called scope gate or grate is attached to the bottom surface of the boat body to cover said water intake port.
The scope gate which has heretofore been most popular, as shown in Figs. 12 and 13, is in the form of an elongated rectangle comprising a pair of front and rear attaching . . .
;~044349 seats 1 and 2 and a pair of side bars 3 and 4, said lattice having one or more partition bars 5 projecting parallel wlth said side bars 3 and 4. At any rate, the whole structure is usually made by casting of aluminum alloy or other light metal. The side bars 3 and 4 and partition bar 5 are shown circular in cross section in these figures, but bars having vertically elongated elliptical and rectangular cross sections are also known.
Such scope gate is removably or exchangeably attached to the bottom surface of the boat body to cover the water intake port while projecting somewhat downward. In the attached state, the side bars 3 and 4 and partitlon bar 5 extend parallel wlth the travel center line of the boat body, so that, coupled with the high rigidity of the metal product, they add to the straight-travel stability during glldlng of the boat body.
Since it is attached to the bottom surface of the boat body in such a manner as to project somewhat downward, even if the boat body runs on shallows or on drifting wood, the bottom surface will not hit the same; thus, the scope gate serves to prevent the boat body from being damaged.
Furthermore, during the turning of the boat body, it provides the boat body with a sldeslip preventing effect (so-called edging effect) with sald side bars 3 and 4 and partltion bar 5 servlng as fins, and lt also increases the rate of flow of water into said water Intake port.
Further, another advantage Is that the larger the number of partition bars, the greater the effect of preventing entry of obstacles.
However, such advantages will not necessarily manifest themselves during the turnlng of the boat body. The reason is that the scope gate is made of metal.
More particularly, first, if the conventional scope gate projects too much downward from the bottom surface of the boat body, the sideslip preventing effect of the side bars 3 and 4 and partltion bar 5 on the boat body will be excessively high owing to the high rigidity of the metal product, resulting in a high resistance to the turning of the boat body to make it dlfficult to attain smooth steering of the boat body. For beglnners, such conventional scope gate even has the danger of rolllng the boat body sldeways.
On the contrary, if It does not at all projcct downward from the bottom surface of the boat body, the aforesaid advantages cannot be obtalned. ~ich exPerlence is requlred in determining the moderate amount of pro~ectlon. It seems that a scope gate equlPPed wlth a projection adjusting mechanlsm has not been commerclally avallable.
Secondly, even If the rate of flow of water into the water Intake port can be Increased by attaching the scope gate to the bottom surface of the boat body In such a manner as to project downward therefrom, the high rigldlty of the metal product causes the side bars 3 and 4 and partitlon bar ~U44349 5 to excessively hold back the natural flow of water movlng from the water intake port to the water intake duct, or the water dashes against them and is thereby agitated, bubbling and disturbed.
As a resultl cavitation takes place ln the water intake duct (or pump case), corroding the lmpeller or causing energy loss. It is clear that the larger the number of said partition bars 5, the more noticeable are such problems.
Thirdly, since the conventional scope gate is a metal product, it forms an obstacle to visual inspection of the interlor of the water intake duct through the water intake port of the boat body. For example, if a floating obstacle enters the water intake duct and twines itself around the impeller, impeller shaft or the like, the twining state cannot be visually inspected unless the boat body is turned upside down to bring its bottom surface into view, and this operation of turning upside down requlres hard labor. And the larger the number of partition bars 5, the more remarkable is such problem.
Fourthly, essentlally such scope gate is used by being removably or exchangeably attached to the bottom surface of the boat body in accordance with the user's taste, steering skill and experlence. And the attaching bolts tend to loosen owing to vibrations or chocks produced in the boat body during the gliding of the boat body. Not infrequently, It is only after the user has landed that he finds that the scope gate is missing.
Therefore in practice a sllicone type blnder ls applled to the scope gate attaching bolts despite the fact that the scope gate is intended to be removably attached to the boat body. If the scope gate should be missing since the conventional scope gate is a metal product it sinks into depths never to be found thus polluting the sea and lakes.
SUMMARY OF THE INVENTION
The present invention has been proposed to solve these problems.
First an object of the inventlon is to provide an arrangement wherein the scope gate is made of polYcarbonate resin or other engineerlng plastic materlal having hlgh bending rigidity said scope gate being in the form of an elongated rectangle having a pair of attaching seats and a palr of flow regulating vertlcal walls said flow regulating vertical walls being adapted to be laterally flexed like plate springs durlng the turning of the boat body;
therefore even if it ls attached to the boat body to project downward from the bottom surface of the boat body lt does not glve the boat body an excesslvely high sldeslip preventing effect so that even a beginner can steer the boat body for turnlng safely and smoothly while assurlng smooth reliable water drawing action without holdlng back the natural flow of water moving from the water lntake port to the water lntake duct or without undesirably agitating water or decreasing the flow rate of water, thereby preventlng cavitation from taking place in the water intake duct.
Particularly, if the cross-sections of the flow regulating vertical walls capable of deforming like plate springs are shaped symmetrical and in the form of a basic triangle or trapezoid with its thickness gradually decreasing upward, it follows that if the boat body is tilted during turning, since the upwardly tapered surfaces of the flow regulating vertical walls are flexed into substantially parallel relation to the water surface, the ob~ect of smoothlng the flow of water moving from the water intake port to the water intake duct can be rationallY
attained.
Secondly, an object of the invention is to provide an arrangement wherein a partition flow regulating vertical wall is installed parallel with and between said flow regulating vertical walls, said partition flow regulating vertical wall having a substantially isosceles triangular cross-section wlth lts thickness gradually decreaslng upward, whereby the scope gate ls internally partitioned to make it difficult for floatlng obstacles to enter and the water drawlng action during the turning of the boat body is smoothed.
z044:~49 Thirdly, an ob3ect of the invention is to provide an arrangement wherein t~)e lower surface reglons of the flow regulating vertical walls are substantially V-shaped as seen laterally of the boat body with their lower edges pro3ecting graduallY downward starting with the opposite sides toward the middle, whereby, despite the fact that the scope gate itself is a plastic product allowing the flow regulating vertical walls to flex, the intermediate regions of the flow regulating vertical walls farthest from the pair of opposed seats are physically structurally reinforced to increase the durability of the scope gate.
Fourthly, an object of the invention is to provide an arrangement wherein the scope gate is made of transparent or translucent plastic material so that it can be seen through;
thus, the interior of the water intake duct can be reliably vlsually inspected from the water intake port wlthout having to turn the boat body upside down to bring its bottom surface Into vlew.
This ob3ect can also be attained even If sald partition flow regulatlng vertlcal wall is added, so long as it is also transparent or translucent.
Fifthly, an ob3ect of the invention is to provide an arrangement wherein the scope gate, whlch Is a molding of plastic material, is colored with a coloring agent, particularly with a fluorescent material, so that if an accident should happen in the offing to make the boat body incapable of traveling, the coloration facilitates search for the boat body. Further, slnce the scope gate is a plastic prod~ct, lt floats on water, a fact which also facilitates search if it should be missing.
Slxthly, an object of the invention is to provlde an arrangement wherein the open edges of the pair of attaching seats opposed to the interior of the lattice of the scope gate are formed as slope surfaces rearwardly ascending at given angles, whereby water is introduced lnto the water intake port with much less resistance during travel of the boat body.
Other objects as well as the arrangement of the invention will become apparent from the following detailed description of preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. l is a schematic side view of a jet-propelled gliding boat with the present invention applied thereto;
Fig. 2 is an enlarged bottom view showing the rear portion of the boat body;
Fig. 3 is a sectional view taken along the line 3-3 ln Fig. 2;
Fig. 4 is a perspective view of a scope gate;
Fig. 5 is a sectional view taken along the line 5-5 in . ~ig. 4;
Fig. 6 is an enlarged sectional view taken along the Z~44349 line 6-G in Fig. 4;
Figs. 7 and 8 are front sectional views showing two modifications corresponding to Fig. 6;
Fig. 9 is a front sectional view for explainlng flexure produced in the scope gate during the turning of the boat body:
Fig. 10 is a perspective view showing a modification of a scope gate corresponding to Fig. 4;
~_ Fig. 11 is an enlarged sectional view taken along the line 11-11 in fig. 10;
Fig. 12 is a perspectlve view showing a conventlonal scope gate; and Fig. 13 is an enlarged sectional view taken along the line 13-13 in Fig. 12.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The concrete arrangement of the invention will now be descrlbed in detail with reference to the drawings. In Fig.
1 schematically showlng a 3et-propelled small-sized gliding boat in its entirety, the character A generally denotes a boat body made of fiber-reinforced plastic (FRP), said boat body being of hollow sealed construction including a front region defined as an engine room 10 and a rear region with its upper surface defined as a floor deck 11 for a driver to ride in a standing posture. In some cases, the middle area of the floor deck 11 will be provided with a seat for a _g_ driver. The numeral 12 denotes an engine contained ln the engine room 10 for drlving a jet-propelling device (water jet pump) B through a propeller shaft 13 to impart a propelling force to the boat body 9.
The propeller shaft 13 extends along the travel center line of the boat body A to a position below the floor deck 11 and is connected at lts front end to the crank shaft (not shown) of the engine 12 through a clutch 14. Integrally rotatably connected to the rear end of the ~peller shaft 13 are an impeller 15 and guide vanes 16. The numeral 17 denotes a water intake duct serving as a pump case for receiving the impeller 15 and guide vanes 16, said water intake duct being disposed below the floor deck 11, with its front side providing a water intake port 18 which opens in the middle of the bottom surface of the boat body A.
When the impeller shaft 13 is driven for rotation, its impeller 15 draws water through the water intake port 18.
ln the water intake duct 17, the water drawn is accelerated and forced rearward by the impeller 15 and its flow is regulated by the guide vanes 16, thereupon It is spouted out through a steering nozzle 19 which opens in the stern of the boat body 9; the reaction to the spouting force advances the boat body A.
The steerlng nozzle 19 is manually controlled from the floor deck 11 to change its direction, whereby the boat body A can be steered. In addition, the numeral 20 denotes a Z(~44349 pump case cover attached to the middle region of the bottom surface of the boat body A.
Slnce there Is a danger of garbage, seaweed, flshing lines and other various floating obstacles belng drawn in together with water through the water intake port 18, a scope gate C for preventing entry thereof is attached to the middle region of the bottom surface of the boat body A to cover the water intake port 18, as shown in Figs. 2 and 3.
In the present invention, the scope gate C is made by in~ection molding of a polycarbonate resin ~preferably, one marketed under the trade name of Taflon, from Idemitu Petroleum Chemistry Co., Ltd.) having high bending rigidity (desirably, about 23,000 kg/cm2 or above), polyacetal resin or other thermoplastic engineering plastic material into the form of an elongated rectangle, as shown In Figs. 4 through 6, the entire molding being transparent.
In Figs. 4 through 6 showing the scope gate C, the numerals 21 and 22 denote a pair of attaching seats having a width w smaller than the width s of said water intake port 18. The front attaching seat 21 has a pair of bolt receivin~ holes 23 on opposite sides, while the rear attaching seat 22 is centrally formed with a bolt receiving hole 24 which desirably is elongated in the longitudinal direction. The number and dispositlon of bolt recelving holes 23, 24 may be freely changed In connection with the boat body A.
The attachlng seats 21 and 22 are applied at thelr flat surfaces to the bottom surface of the boat body A and then fixed thereto by stud bolts 25 and 26 so that the scope gate C can be removed or exchanged.
The open edges of the attachlng seats 21 and 22 of the scope gate C opposed to the Interior of the lattlce are formed as slope surfaces 21a and 22a rearwardly ascendlng at given angles ~ and p with respect to the horizontal surface.
Thus, water can be smoothly drawn from the water lntake ~- bodv port 18 of the boat/A lnto the water intake duct wlthout disturbing water.
The numerals 27 and 28 denote a palr of flow regulatlng vertical walls spannlng the space between the attachlng seat 21 and 22 and extending across the water intake port 18 of the boat body A with the lateral surfaces thereof being approximately orthogonal to the attaching surfaces of sald seats.
Thus, coupled wlth the fact that the scope gate C itself is made of sald plastic materlal, thls arrangement ensures that durlng the turnlng of the boat body A, the urglng force of water ls supported by the uprlght surfaces of the flow regulating vertlcal walls 27 and 28, whlch then flex to and fro as shown ln chain lines in ~ig. 9 as if they were plate sprlngs. This flexure of the flow regulating vertlcal walls 27 and 28 al IOW6 water to flow wlthout excesslvely holding back or dlsturblng the same; thus, water is smoothly drawn in through the water intake port 18 of the boat body A.
~o(l Y
In addltion, when the boat/~ s travelIng stralght wlth the uprlght lateral surfaces receiving no pressure of water laterally of the boat body A, the flow regulatlng vertlcal walls 27 and 28 are, of course, restored to the original state.
Further, the cross-sections of the flow regulatlng vertical walls 27 and 28 are shaped symmetrical and In the form of a basic triangle or trapezoid with its thickness as sllown in Fig. 6.
gradually decreasing upward, /That is, the lateral surfaces of the flow regulatlng vertical walls 27 and 28 are slope surfaces 27a, 27b and 28a, 28b with the thickness gradually decreasing upward at angles of r and ~.
As a result, water can be extremely smoothly drawn into the water inLake port 18 as It Is gulded to the travel center line of the boat body A. Further, even if the boat body A Is tilted durlng turnlng, the flow regulating vertlcal walls of the scope gate C integral therewlth are also tilted sUch that their upright lateral surfaces are orthogonal to the water surface as suggested In Fle. 9.
Therefore, holdlng back and disturbance of water are suppressed, and substantlally the same amount of water as durlng 8 tralght travel Is smoothly drawn from the water Intake port 18 Into the water Intake duct 17.
For this reason, the cross-sectlons of the flow reeulatlng vertlcal walls 27 and 28 should, most 204~349 effectlvely, be In the shape of an isosceles trapezoid shown in Fig. 6, or a modification thereof such as an ellipse, an oval or a waterdrop, as shown in Flg. 7. However, so long as the symmetrical cross-sections of the flow regulating vertical walls 27 and 28 are malntained, the cross-sections may be in the form of a non-isosceles trapezold, as shown in Fig. 8, or a right triangle.
When the flow regulating vertical walls 27 and 28 are seen laterally of the boat body A, as is clear from Figs. 3 through 5, their upper surfaces are horizontal, whereas their lower surfaces are V-shaped gradually downwardly projectlng as the approximately intermediate region Is reached.
That is, the lower surfaces of the approximately front halves of the flow regulatlng vertical walls 27 and 28 are forwardly upward slope surface 27c and 28c connected flush to the lower surface of the front attaching seat 21, while the lower surfaces of the remaining rear halves are rearwardly upward slope surface 27d and 28d connected flush to the lower surface of the rear attaching seat 22; thus, the approxlmately middle region where the slope surfaces 27c, 28c, 27d, 28d cross each other projects downward by the greatest amount. The character A denotes the crossing angle between the forwardly and rearwardly upward slope surfaces 27c, 28c, 27d, 28d.
Thus, the scope gate C itself Is integrally made of said X(~4349 plastic material to enable the flow regulating vertlc~l walls 27 and 28 to flex durlng turning movement, whlle the intermediate region between the flow regulatlng vertical walls 27 and 28 remotest from the attaching seats 21 and 22 can be strengthened to be free from the danger of belng physically broken. Further, the front halves of the flow regulating vertical walls 27 and 28 have their lower surfaces designed to define forwardly slope surfaces 27c and 28c; therefore, the boat body 9 can be given lift by water acting on said surfaces during travel of the boat body A.
Figs. lO and ll show a modification of a scope gate corresponding to Figs. 4 through 6, and the relation to Figs. 4 through 6 is indicated by multlplylng the numbers by lO. In this modification, a partition flow regulating vertical wall 290 is interposed between the flow regulating vertical walls 270 and 280 in parallel relation to the latter, thereby enhanclng the effect of preventing entrY of floating obstacles. The cross-sectional shape of the partition flow regulating vertical wall 290 is determined in positional relation to the flow regulating vertical walls 270 and 280; thus, it is an isosceles trapezoid or an a~ own in Fi1r. 11 Isosceles triangle,/or it is a modification of said figure, such as an ellipse or a waterdrop shape. In addition, the partltlon flow regulating vertlcal wall 290 may be Increased In number to two or more so long as they extend parallel with the flow regulatlng vertical walls 270 and 280.
.
At any rate, in attaching the scope gate C to the bottom surface of the boat body A, lt Is effective, as is suggested in Fig. 3, to position it such that the rear halves of the flow regulating vertical walls 27 and 28 proiect downward beyond the bottom surface of the boat body A by a glven amount h-Thereby, floatlng obstacles tendine to adhere to the rear end of the water intake port 18 formed in the bottom surface of the boat body A are qulckly guided rearward bY
the rear halves of the flow regulating vertical walls 27 and 28 projecting downward beyond the bottom surface of the boat body A. Further, when the boat body A is turning, the rear halves of the flow regulatlng vertical walls 27 and 28 exhlblt the effect of preventing sidesllp of the boat body A. However, in that case, slnce the flow regulating vertlcal walls 27 and 28 themselves wlll flex to and fro, as descrlbed above, there Is no danger of the sideslip preventing effect being too high.
It has been stated that the scope gate C is molded of tranæparent or translucent plastlc material, In addition to this transparency, It Is desirable to apply a suitable fluorescent coloring agent. Then, even If an accldent whlch makes lt Impossible for the boat body A to glide should happen, the boat body can be easily searched for with the color as a gulde.
As descrlbed above, the scope gate C of the present ~OA4349 Invention is integrally molded of transparent or translucent engineering plastlc material into the form of an elongated lattice, and a pair of longitudinally extending flow regulating vertical walls 27 and 28 are adapted to flex to and fro during the turning of the boat body A. Thus, water can be drawn very smoothly without the danger of excesslvely holding back or disturbing the flow of water moving from the water intake port 18 to the water intake duct 17 or the danger of decreasing the flow rate of water. Nor is the danger of causing cavitation in the water intake duct 17.
Further, since the scope gate C can be seen through, the interior of the water intake duct 17 can be inspected by simply glancing at the water intake port 18 without having to turn the boat body A over to bring its bottom surface into view. Such effect will not be lost even if the partition flow regulating vertical wall 290 is interposed to partition the lattice, and the efficiency of inspection and maintenance is high.
Partlcularly, lf the cross-sections of the flow regulating vertical walls 27 and 28 are made symmetrlcal and In the form of a baslc triangle or trapezold with its thickness gradually decreas}ng upward, then water can be cxtremely smoothly drawn into the water lntake port 18 along the travel center line during straight travel of the boat body A. Further, if the boat body A ls tilted durlng Its turnlng, the upwardly converging slope surfaces 27a, 27b and 20~i4349 28a, 28b of the flow regulating vertlcal walls 27 and 28 are caused to be orthogonal to the water surface. This, coupled with said flexure, causes the same amount of water as during straight travel to flow into the water intake port 18 while more smoothly regulating the flow without the danger of the flow regulating vertical walls 27 and 28 holding back or disturbing water.
If the bottom surfaces of the flow regulating vertical walls 27 and 28 are V-shaped, as seen laterally of the boat body A, gradually downwardly pro~ecting as the approximately lntermediate regions are reached, then the approxlmately intermediate regions of the flow regulating vertical walls 27 and 28 remotest from the palr of attaching seats 21 and 22 can be physically reinforced to be free from damage thereto whlle maklng the scope gate C itself in the form of a plastlc article to allow the flow regulating vertical walls 27 and 28 to flex; thus, the durability is enhanced.
Further, if a partltlon flow regulatlng vertical wall 290 is Interposed between the flow regulating vertlcal walls 270 and 280 in parallel relation to the latter and its cross-section is in the form of an lsosceles triangle or an Isosceles trapezoid with Its thlckness gradually decreasing upward, then slnce the interlor of the lattice of the scope gate C is partltioned by the partltlon flow regulatlng vertical wall 290, the entry of floatlng obstacles into the water Intake port 18 can be prevented more reliably whlle 20443~9 said flexure is being exhibited during the turning of the boat bodY 9-lf the open edges of the attaching seats 21 and 22 ofthe scope gate C opposed to the interior of the lattice are formed as slope surfaces 21a and 22a rearwardly ascending at given angles a and ~, then water can be introduced more smoothly into the water intake port 18 by the rearwardly ascending slope surfaces 21a and 22a of the attaching seats 21 and 22.
Further, if the entire scope gate C ls calored preferably with a fluorescent colorlng agent, the boat body 9 can be given an external appearance which is harmonious with the boat body C. Thus, if an accident which makes gliding impossible or an accident of coming off of the scope gate C should happen in the offing, the search thereof is facilitated.
WATER DRA'~ING AND GUIDING DEVICE
FOl~ Jl~`'r~ OPl~,I,I,~I~ GL,IDIIlG ~OATS
BACKGROUND OF THE INVENTION
Small-sized gliding boats of the jet-propelled type arranged for a single person to ride in a standing posture or some persons to ride in a seated posture have incorporated therein a jet-propelllng device (or water jet pump) adapted to be driven for rotation by an engine mounted on the boat.
Such jet propelling device is designed to draw water through a water intake port formed in the bottom surface of the boat body, accelerating said water by~an impeller installed in a water intake duct (or pump case) to spout it rearwardly of the boat body, the reaction force serving as the propelling force for the boat body. Thus, the jet propelllng device has the danger of drawing not only water but also garbage, seaweed, fishing lines and other various floating obstacles. Therefore, to prevent entry of suc~l obstacles, a special lattice called scope gate or grate is attached to the bottom surface of the boat body to cover said water intake port.
The scope gate which has heretofore been most popular, as shown in Figs. 12 and 13, is in the form of an elongated rectangle comprising a pair of front and rear attaching . . .
;~044349 seats 1 and 2 and a pair of side bars 3 and 4, said lattice having one or more partition bars 5 projecting parallel wlth said side bars 3 and 4. At any rate, the whole structure is usually made by casting of aluminum alloy or other light metal. The side bars 3 and 4 and partition bar 5 are shown circular in cross section in these figures, but bars having vertically elongated elliptical and rectangular cross sections are also known.
Such scope gate is removably or exchangeably attached to the bottom surface of the boat body to cover the water intake port while projecting somewhat downward. In the attached state, the side bars 3 and 4 and partitlon bar 5 extend parallel wlth the travel center line of the boat body, so that, coupled with the high rigidity of the metal product, they add to the straight-travel stability during glldlng of the boat body.
Since it is attached to the bottom surface of the boat body in such a manner as to project somewhat downward, even if the boat body runs on shallows or on drifting wood, the bottom surface will not hit the same; thus, the scope gate serves to prevent the boat body from being damaged.
Furthermore, during the turning of the boat body, it provides the boat body with a sldeslip preventing effect (so-called edging effect) with sald side bars 3 and 4 and partltion bar 5 servlng as fins, and lt also increases the rate of flow of water into said water Intake port.
Further, another advantage Is that the larger the number of partition bars, the greater the effect of preventing entry of obstacles.
However, such advantages will not necessarily manifest themselves during the turnlng of the boat body. The reason is that the scope gate is made of metal.
More particularly, first, if the conventional scope gate projects too much downward from the bottom surface of the boat body, the sideslip preventing effect of the side bars 3 and 4 and partltion bar 5 on the boat body will be excessively high owing to the high rigidity of the metal product, resulting in a high resistance to the turning of the boat body to make it dlfficult to attain smooth steering of the boat body. For beglnners, such conventional scope gate even has the danger of rolllng the boat body sldeways.
On the contrary, if It does not at all projcct downward from the bottom surface of the boat body, the aforesaid advantages cannot be obtalned. ~ich exPerlence is requlred in determining the moderate amount of pro~ectlon. It seems that a scope gate equlPPed wlth a projection adjusting mechanlsm has not been commerclally avallable.
Secondly, even If the rate of flow of water into the water Intake port can be Increased by attaching the scope gate to the bottom surface of the boat body In such a manner as to project downward therefrom, the high rigldlty of the metal product causes the side bars 3 and 4 and partitlon bar ~U44349 5 to excessively hold back the natural flow of water movlng from the water intake port to the water intake duct, or the water dashes against them and is thereby agitated, bubbling and disturbed.
As a resultl cavitation takes place ln the water intake duct (or pump case), corroding the lmpeller or causing energy loss. It is clear that the larger the number of said partition bars 5, the more noticeable are such problems.
Thirdly, since the conventional scope gate is a metal product, it forms an obstacle to visual inspection of the interlor of the water intake duct through the water intake port of the boat body. For example, if a floating obstacle enters the water intake duct and twines itself around the impeller, impeller shaft or the like, the twining state cannot be visually inspected unless the boat body is turned upside down to bring its bottom surface into view, and this operation of turning upside down requlres hard labor. And the larger the number of partition bars 5, the more remarkable is such problem.
Fourthly, essentlally such scope gate is used by being removably or exchangeably attached to the bottom surface of the boat body in accordance with the user's taste, steering skill and experlence. And the attaching bolts tend to loosen owing to vibrations or chocks produced in the boat body during the gliding of the boat body. Not infrequently, It is only after the user has landed that he finds that the scope gate is missing.
Therefore in practice a sllicone type blnder ls applled to the scope gate attaching bolts despite the fact that the scope gate is intended to be removably attached to the boat body. If the scope gate should be missing since the conventional scope gate is a metal product it sinks into depths never to be found thus polluting the sea and lakes.
SUMMARY OF THE INVENTION
The present invention has been proposed to solve these problems.
First an object of the inventlon is to provide an arrangement wherein the scope gate is made of polYcarbonate resin or other engineerlng plastic materlal having hlgh bending rigidity said scope gate being in the form of an elongated rectangle having a pair of attaching seats and a palr of flow regulating vertlcal walls said flow regulating vertical walls being adapted to be laterally flexed like plate springs durlng the turning of the boat body;
therefore even if it ls attached to the boat body to project downward from the bottom surface of the boat body lt does not glve the boat body an excesslvely high sldeslip preventing effect so that even a beginner can steer the boat body for turnlng safely and smoothly while assurlng smooth reliable water drawing action without holdlng back the natural flow of water moving from the water lntake port to the water lntake duct or without undesirably agitating water or decreasing the flow rate of water, thereby preventlng cavitation from taking place in the water intake duct.
Particularly, if the cross-sections of the flow regulating vertical walls capable of deforming like plate springs are shaped symmetrical and in the form of a basic triangle or trapezoid with its thickness gradually decreasing upward, it follows that if the boat body is tilted during turning, since the upwardly tapered surfaces of the flow regulating vertical walls are flexed into substantially parallel relation to the water surface, the ob~ect of smoothlng the flow of water moving from the water intake port to the water intake duct can be rationallY
attained.
Secondly, an object of the invention is to provide an arrangement wherein a partition flow regulating vertical wall is installed parallel with and between said flow regulating vertical walls, said partition flow regulating vertical wall having a substantially isosceles triangular cross-section wlth lts thickness gradually decreaslng upward, whereby the scope gate ls internally partitioned to make it difficult for floatlng obstacles to enter and the water drawlng action during the turning of the boat body is smoothed.
z044:~49 Thirdly, an ob3ect of the invention is to provide an arrangement wherein t~)e lower surface reglons of the flow regulating vertical walls are substantially V-shaped as seen laterally of the boat body with their lower edges pro3ecting graduallY downward starting with the opposite sides toward the middle, whereby, despite the fact that the scope gate itself is a plastic product allowing the flow regulating vertical walls to flex, the intermediate regions of the flow regulating vertical walls farthest from the pair of opposed seats are physically structurally reinforced to increase the durability of the scope gate.
Fourthly, an object of the invention is to provide an arrangement wherein the scope gate is made of transparent or translucent plastic material so that it can be seen through;
thus, the interior of the water intake duct can be reliably vlsually inspected from the water intake port wlthout having to turn the boat body upside down to bring its bottom surface Into vlew.
This ob3ect can also be attained even If sald partition flow regulatlng vertlcal wall is added, so long as it is also transparent or translucent.
Fifthly, an ob3ect of the invention is to provide an arrangement wherein the scope gate, whlch Is a molding of plastic material, is colored with a coloring agent, particularly with a fluorescent material, so that if an accident should happen in the offing to make the boat body incapable of traveling, the coloration facilitates search for the boat body. Further, slnce the scope gate is a plastic prod~ct, lt floats on water, a fact which also facilitates search if it should be missing.
Slxthly, an object of the invention is to provlde an arrangement wherein the open edges of the pair of attaching seats opposed to the interior of the lattice of the scope gate are formed as slope surfaces rearwardly ascending at given angles, whereby water is introduced lnto the water intake port with much less resistance during travel of the boat body.
Other objects as well as the arrangement of the invention will become apparent from the following detailed description of preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. l is a schematic side view of a jet-propelled gliding boat with the present invention applied thereto;
Fig. 2 is an enlarged bottom view showing the rear portion of the boat body;
Fig. 3 is a sectional view taken along the line 3-3 ln Fig. 2;
Fig. 4 is a perspective view of a scope gate;
Fig. 5 is a sectional view taken along the line 5-5 in . ~ig. 4;
Fig. 6 is an enlarged sectional view taken along the Z~44349 line 6-G in Fig. 4;
Figs. 7 and 8 are front sectional views showing two modifications corresponding to Fig. 6;
Fig. 9 is a front sectional view for explainlng flexure produced in the scope gate during the turning of the boat body:
Fig. 10 is a perspective view showing a modification of a scope gate corresponding to Fig. 4;
~_ Fig. 11 is an enlarged sectional view taken along the line 11-11 in fig. 10;
Fig. 12 is a perspectlve view showing a conventlonal scope gate; and Fig. 13 is an enlarged sectional view taken along the line 13-13 in Fig. 12.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The concrete arrangement of the invention will now be descrlbed in detail with reference to the drawings. In Fig.
1 schematically showlng a 3et-propelled small-sized gliding boat in its entirety, the character A generally denotes a boat body made of fiber-reinforced plastic (FRP), said boat body being of hollow sealed construction including a front region defined as an engine room 10 and a rear region with its upper surface defined as a floor deck 11 for a driver to ride in a standing posture. In some cases, the middle area of the floor deck 11 will be provided with a seat for a _g_ driver. The numeral 12 denotes an engine contained ln the engine room 10 for drlving a jet-propelling device (water jet pump) B through a propeller shaft 13 to impart a propelling force to the boat body 9.
The propeller shaft 13 extends along the travel center line of the boat body A to a position below the floor deck 11 and is connected at lts front end to the crank shaft (not shown) of the engine 12 through a clutch 14. Integrally rotatably connected to the rear end of the ~peller shaft 13 are an impeller 15 and guide vanes 16. The numeral 17 denotes a water intake duct serving as a pump case for receiving the impeller 15 and guide vanes 16, said water intake duct being disposed below the floor deck 11, with its front side providing a water intake port 18 which opens in the middle of the bottom surface of the boat body A.
When the impeller shaft 13 is driven for rotation, its impeller 15 draws water through the water intake port 18.
ln the water intake duct 17, the water drawn is accelerated and forced rearward by the impeller 15 and its flow is regulated by the guide vanes 16, thereupon It is spouted out through a steering nozzle 19 which opens in the stern of the boat body 9; the reaction to the spouting force advances the boat body A.
The steerlng nozzle 19 is manually controlled from the floor deck 11 to change its direction, whereby the boat body A can be steered. In addition, the numeral 20 denotes a Z(~44349 pump case cover attached to the middle region of the bottom surface of the boat body A.
Slnce there Is a danger of garbage, seaweed, flshing lines and other various floating obstacles belng drawn in together with water through the water intake port 18, a scope gate C for preventing entry thereof is attached to the middle region of the bottom surface of the boat body A to cover the water intake port 18, as shown in Figs. 2 and 3.
In the present invention, the scope gate C is made by in~ection molding of a polycarbonate resin ~preferably, one marketed under the trade name of Taflon, from Idemitu Petroleum Chemistry Co., Ltd.) having high bending rigidity (desirably, about 23,000 kg/cm2 or above), polyacetal resin or other thermoplastic engineering plastic material into the form of an elongated rectangle, as shown In Figs. 4 through 6, the entire molding being transparent.
In Figs. 4 through 6 showing the scope gate C, the numerals 21 and 22 denote a pair of attaching seats having a width w smaller than the width s of said water intake port 18. The front attaching seat 21 has a pair of bolt receivin~ holes 23 on opposite sides, while the rear attaching seat 22 is centrally formed with a bolt receiving hole 24 which desirably is elongated in the longitudinal direction. The number and dispositlon of bolt recelving holes 23, 24 may be freely changed In connection with the boat body A.
The attachlng seats 21 and 22 are applied at thelr flat surfaces to the bottom surface of the boat body A and then fixed thereto by stud bolts 25 and 26 so that the scope gate C can be removed or exchanged.
The open edges of the attachlng seats 21 and 22 of the scope gate C opposed to the Interior of the lattlce are formed as slope surfaces 21a and 22a rearwardly ascendlng at given angles ~ and p with respect to the horizontal surface.
Thus, water can be smoothly drawn from the water lntake ~- bodv port 18 of the boat/A lnto the water intake duct wlthout disturbing water.
The numerals 27 and 28 denote a palr of flow regulatlng vertical walls spannlng the space between the attachlng seat 21 and 22 and extending across the water intake port 18 of the boat body A with the lateral surfaces thereof being approximately orthogonal to the attaching surfaces of sald seats.
Thus, coupled wlth the fact that the scope gate C itself is made of sald plastic materlal, thls arrangement ensures that durlng the turnlng of the boat body A, the urglng force of water ls supported by the uprlght surfaces of the flow regulating vertlcal walls 27 and 28, whlch then flex to and fro as shown ln chain lines in ~ig. 9 as if they were plate sprlngs. This flexure of the flow regulating vertlcal walls 27 and 28 al IOW6 water to flow wlthout excesslvely holding back or dlsturblng the same; thus, water is smoothly drawn in through the water intake port 18 of the boat body A.
~o(l Y
In addltion, when the boat/~ s travelIng stralght wlth the uprlght lateral surfaces receiving no pressure of water laterally of the boat body A, the flow regulatlng vertlcal walls 27 and 28 are, of course, restored to the original state.
Further, the cross-sections of the flow regulatlng vertical walls 27 and 28 are shaped symmetrical and In the form of a basic triangle or trapezoid with its thickness as sllown in Fig. 6.
gradually decreasing upward, /That is, the lateral surfaces of the flow regulatlng vertical walls 27 and 28 are slope surfaces 27a, 27b and 28a, 28b with the thickness gradually decreasing upward at angles of r and ~.
As a result, water can be extremely smoothly drawn into the water inLake port 18 as It Is gulded to the travel center line of the boat body A. Further, even if the boat body A Is tilted durlng turnlng, the flow regulating vertlcal walls of the scope gate C integral therewlth are also tilted sUch that their upright lateral surfaces are orthogonal to the water surface as suggested In Fle. 9.
Therefore, holdlng back and disturbance of water are suppressed, and substantlally the same amount of water as durlng 8 tralght travel Is smoothly drawn from the water Intake port 18 Into the water Intake duct 17.
For this reason, the cross-sectlons of the flow reeulatlng vertlcal walls 27 and 28 should, most 204~349 effectlvely, be In the shape of an isosceles trapezoid shown in Fig. 6, or a modification thereof such as an ellipse, an oval or a waterdrop, as shown in Flg. 7. However, so long as the symmetrical cross-sections of the flow regulating vertical walls 27 and 28 are malntained, the cross-sections may be in the form of a non-isosceles trapezold, as shown in Fig. 8, or a right triangle.
When the flow regulating vertical walls 27 and 28 are seen laterally of the boat body A, as is clear from Figs. 3 through 5, their upper surfaces are horizontal, whereas their lower surfaces are V-shaped gradually downwardly projectlng as the approximately intermediate region Is reached.
That is, the lower surfaces of the approximately front halves of the flow regulatlng vertical walls 27 and 28 are forwardly upward slope surface 27c and 28c connected flush to the lower surface of the front attaching seat 21, while the lower surfaces of the remaining rear halves are rearwardly upward slope surface 27d and 28d connected flush to the lower surface of the rear attaching seat 22; thus, the approxlmately middle region where the slope surfaces 27c, 28c, 27d, 28d cross each other projects downward by the greatest amount. The character A denotes the crossing angle between the forwardly and rearwardly upward slope surfaces 27c, 28c, 27d, 28d.
Thus, the scope gate C itself Is integrally made of said X(~4349 plastic material to enable the flow regulating vertlc~l walls 27 and 28 to flex durlng turning movement, whlle the intermediate region between the flow regulatlng vertical walls 27 and 28 remotest from the attaching seats 21 and 22 can be strengthened to be free from the danger of belng physically broken. Further, the front halves of the flow regulating vertical walls 27 and 28 have their lower surfaces designed to define forwardly slope surfaces 27c and 28c; therefore, the boat body 9 can be given lift by water acting on said surfaces during travel of the boat body A.
Figs. lO and ll show a modification of a scope gate corresponding to Figs. 4 through 6, and the relation to Figs. 4 through 6 is indicated by multlplylng the numbers by lO. In this modification, a partition flow regulating vertical wall 290 is interposed between the flow regulating vertical walls 270 and 280 in parallel relation to the latter, thereby enhanclng the effect of preventing entrY of floating obstacles. The cross-sectional shape of the partition flow regulating vertical wall 290 is determined in positional relation to the flow regulating vertical walls 270 and 280; thus, it is an isosceles trapezoid or an a~ own in Fi1r. 11 Isosceles triangle,/or it is a modification of said figure, such as an ellipse or a waterdrop shape. In addition, the partltlon flow regulating vertlcal wall 290 may be Increased In number to two or more so long as they extend parallel with the flow regulatlng vertical walls 270 and 280.
.
At any rate, in attaching the scope gate C to the bottom surface of the boat body A, lt Is effective, as is suggested in Fig. 3, to position it such that the rear halves of the flow regulating vertical walls 27 and 28 proiect downward beyond the bottom surface of the boat body A by a glven amount h-Thereby, floatlng obstacles tendine to adhere to the rear end of the water intake port 18 formed in the bottom surface of the boat body A are qulckly guided rearward bY
the rear halves of the flow regulating vertical walls 27 and 28 projecting downward beyond the bottom surface of the boat body A. Further, when the boat body A is turning, the rear halves of the flow regulatlng vertical walls 27 and 28 exhlblt the effect of preventing sidesllp of the boat body A. However, in that case, slnce the flow regulating vertlcal walls 27 and 28 themselves wlll flex to and fro, as descrlbed above, there Is no danger of the sideslip preventing effect being too high.
It has been stated that the scope gate C is molded of tranæparent or translucent plastlc material, In addition to this transparency, It Is desirable to apply a suitable fluorescent coloring agent. Then, even If an accldent whlch makes lt Impossible for the boat body A to glide should happen, the boat body can be easily searched for with the color as a gulde.
As descrlbed above, the scope gate C of the present ~OA4349 Invention is integrally molded of transparent or translucent engineering plastlc material into the form of an elongated lattice, and a pair of longitudinally extending flow regulating vertical walls 27 and 28 are adapted to flex to and fro during the turning of the boat body A. Thus, water can be drawn very smoothly without the danger of excesslvely holding back or disturbing the flow of water moving from the water intake port 18 to the water intake duct 17 or the danger of decreasing the flow rate of water. Nor is the danger of causing cavitation in the water intake duct 17.
Further, since the scope gate C can be seen through, the interior of the water intake duct 17 can be inspected by simply glancing at the water intake port 18 without having to turn the boat body A over to bring its bottom surface into view. Such effect will not be lost even if the partition flow regulating vertical wall 290 is interposed to partition the lattice, and the efficiency of inspection and maintenance is high.
Partlcularly, lf the cross-sections of the flow regulating vertical walls 27 and 28 are made symmetrlcal and In the form of a baslc triangle or trapezold with its thickness gradually decreas}ng upward, then water can be cxtremely smoothly drawn into the water lntake port 18 along the travel center line during straight travel of the boat body A. Further, if the boat body A ls tilted durlng Its turnlng, the upwardly converging slope surfaces 27a, 27b and 20~i4349 28a, 28b of the flow regulating vertlcal walls 27 and 28 are caused to be orthogonal to the water surface. This, coupled with said flexure, causes the same amount of water as during straight travel to flow into the water intake port 18 while more smoothly regulating the flow without the danger of the flow regulating vertical walls 27 and 28 holding back or disturbing water.
If the bottom surfaces of the flow regulating vertical walls 27 and 28 are V-shaped, as seen laterally of the boat body A, gradually downwardly pro~ecting as the approximately lntermediate regions are reached, then the approxlmately intermediate regions of the flow regulating vertical walls 27 and 28 remotest from the palr of attaching seats 21 and 22 can be physically reinforced to be free from damage thereto whlle maklng the scope gate C itself in the form of a plastlc article to allow the flow regulating vertical walls 27 and 28 to flex; thus, the durability is enhanced.
Further, if a partltlon flow regulatlng vertical wall 290 is Interposed between the flow regulating vertlcal walls 270 and 280 in parallel relation to the latter and its cross-section is in the form of an lsosceles triangle or an Isosceles trapezoid with Its thlckness gradually decreasing upward, then slnce the interlor of the lattice of the scope gate C is partltioned by the partltlon flow regulatlng vertical wall 290, the entry of floatlng obstacles into the water Intake port 18 can be prevented more reliably whlle 20443~9 said flexure is being exhibited during the turning of the boat bodY 9-lf the open edges of the attaching seats 21 and 22 ofthe scope gate C opposed to the interior of the lattice are formed as slope surfaces 21a and 22a rearwardly ascending at given angles a and ~, then water can be introduced more smoothly into the water intake port 18 by the rearwardly ascending slope surfaces 21a and 22a of the attaching seats 21 and 22.
Further, if the entire scope gate C ls calored preferably with a fluorescent colorlng agent, the boat body 9 can be given an external appearance which is harmonious with the boat body C. Thus, if an accident which makes gliding impossible or an accident of coming off of the scope gate C should happen in the offing, the search thereof is facilitated.
Claims (6)
1. A water drawing and guiding device for jet-propelled gliding boats, wherein a scope gate for preventing entry of floating obstacles is attached to a water intake port formed in the bottom surface of the boat body, and the water drawn from the water intake port is accelerated by an impeller housed in a water intake duct and spouted rearwardly of the boat body, said water drawing and guiding device being characterized in that:
said scope gate is made of elastic transparent or translucent engineering plastic material into the form of a longitudinally elongated rectangle having a pair of attacking seats and a pair of flow regulating vertical walls, the arrangement being such that during the turning of the boat body, the flow regulating vertical walls flex to and fro like plate springs.
said scope gate is made of elastic transparent or translucent engineering plastic material into the form of a longitudinally elongated rectangle having a pair of attacking seats and a pair of flow regulating vertical walls, the arrangement being such that during the turning of the boat body, the flow regulating vertical walls flex to and fro like plate springs.
2. A water drawing and guiding device for jet-propelled gliding boats as set forth in Claim 1, wherein the cross-sections of the flow regulating vertical walls are made symmetrical and in the form of a basic triangle or trapezoid with its thickness gradually decreasing upward.
3. A water drawing and guiding device for jet-propelled gliding boats as set forth in Claim 1, wherein a partition flow regulating vertical wall is interposed between the flow , regulating vertical walls in parallel relation to the latter and is formed so that its cross-sectional is in the form of an isosceles triangle or an isosceles trapezoid with its thickness gradually decreasing upward.
4. A water drawing and guiding device for jet-propelled gliding boats as set forth in Claim 1, wherein the bottom surfaces of the flow regulating vertical walls are V-shaped, as seen laterally of the boat body, gradually downwardly projecting as the approximately intermediate regions are reached.
5. A water drawing and guiding device for jet-propelled gliding boats as set forth in Claim 1, wherein the entire scope gate is colored preferably with a fluorescent coloring agent.
6. A water drawing and guiding device for jet-propelled gliding boats as set forth in Claim 1, wherein the open edges of the attacking seats of the scope gate opposed to the interior of the lattice are formed as slope surfaces rearwardly ascending at given angles.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP183178/90 | 1990-07-10 | ||
| JP18317890A JPH0471993A (en) | 1990-07-10 | 1990-07-10 | Water suction introducing device for jet propulsion type gliding boat |
| JP608,441 | 1990-11-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2044349A1 true CA2044349A1 (en) | 1992-01-11 |
Family
ID=16131142
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2044349 Abandoned CA2044349A1 (en) | 1990-07-10 | 1991-06-11 | Water drawing and guiding device for jet-propelled gliding boats |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0465908A1 (en) |
| JP (1) | JPH0471993A (en) |
| AU (1) | AU7920291A (en) |
| CA (1) | CA2044349A1 (en) |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3040695A (en) * | 1960-02-16 | 1962-06-26 | Buehler Corp | Intake strainer |
| US3040696A (en) * | 1960-04-08 | 1962-06-26 | Charles J Dahle | Propulsion and steering unit for boats |
| GB2197626A (en) * | 1986-11-17 | 1988-05-25 | John David Britton | Propeller clearing means |
-
1990
- 1990-07-10 JP JP18317890A patent/JPH0471993A/en active Pending
-
1991
- 1991-06-11 CA CA 2044349 patent/CA2044349A1/en not_active Abandoned
- 1991-06-20 AU AU79202/91A patent/AU7920291A/en not_active Abandoned
- 1991-06-24 EP EP91110377A patent/EP0465908A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0471993A (en) | 1992-03-06 |
| AU7920291A (en) | 1992-01-16 |
| EP0465908A1 (en) | 1992-01-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5520133A (en) | Water jet powered watercraft | |
| US4813365A (en) | Double deadrise with multiple reflex chine boat hull structure and engine mounting system | |
| KR100293301B1 (en) | High Performance Power Water Skiing | |
| CA2354798C (en) | Boat activated wake enhancement method and system | |
| US4691658A (en) | Aquatic sport device | |
| US5140922A (en) | Lift for a watercraft | |
| US3911846A (en) | Stepped hull for jet-powered boat | |
| US5810630A (en) | Attachment assembly for securing a hydrodynamic propulsion surface to a body board | |
| US5498184A (en) | Body board having a hydrodynamic propulsion surface | |
| US20010029136A1 (en) | Two-hand bodysurfing and swimming aid | |
| CA2044349A1 (en) | Water drawing and guiding device for jet-propelled gliding boats | |
| US1918508A (en) | Water sled or surf board | |
| US3726249A (en) | Water craft | |
| JP2008528375A (en) | bow | |
| JPH0471985A (en) | Driven boat | |
| US5738555A (en) | Attachment assembly for securing a hydrodynamic propulsion surface to a body board | |
| JPH0717675Y2 (en) | Side-slip prevention device for jet-propelled planing boat | |
| US5921833A (en) | Oscillating surfboard stringer | |
| US20050106960A1 (en) | Manually Propelled Personal Floatation Device | |
| EP0197528A1 (en) | Small watercraft | |
| JP2621113B2 (en) | Small jet propulsion boat | |
| CN212667608U (en) | EPP floats class kayak | |
| RU2176608C2 (en) | High-speed vessel | |
| US6736688B1 (en) | Manually propelled personal floatation device | |
| JPH05278678A (en) | Towed ship |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |