WATERCRAFT
United States Patent 3702598
A watercraft having a tunnel hull with an aerodynamic curvilinear lifting surface and a propulsion means forward of the aerodynamic lifting surface. The tunnel preferably longitudinally extends substantially the full length of the boat and receives a continuous air flow derived from the forward motion of the craft which acts on the aerodynamic lifting surface to provide a craft lifting force. The craft may be optionally provided with a second air flow passage for the tunnel which includes an air propelling means supplying forced hot air to the tunnel forward of the lifting surface to aid in the generation of the lifting force. In its preferred form, the lift surface has an air foil-like cross section which provides a concave trapping area to augment the lifting effect of the aerodynamic lifting surface. In a first embodiment, a single propulsion device is shown while in a second embodiment three propelling devices and two aerodynamic lifting surfaces are shown in tandem.
US Patent References:
Hydro plane
Goar - June 1963 - 3094962
Water traversing air cushion vehicle
Beardsley - July 1964 - 3140687
Hydro plane
Goar - June 1963 - 3094962
Water traversing air cushion vehicle
Beardsley - July 1964 - 3140687
Application Number:
05/150419
Publication Date:
11/14/1972
Filing Date:
06/07/1971
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
114/290, D12/312, 114/289
International Classes:
B63B1/20; B63B1/16; B63B1/38
Field of Search:
114/66.5R,67A,61,62
Primary Examiner:
Farrell, Andrew H.
Claims:
What is claimed is
1. A craft which is at least partially water borne and is adapted to be forwardly propelled along a longitudinal axis of the craft comprising:
2. A craft according to claim 1 wherein said tunnel substantially extends the full length of said craft.
3. A craft according to claim 1 wherein said tunnel is forwardly opened at least during propulsion of said craft to provide said air passage means with a longitudinally extending part of said air passage means being at least partially defined by said hull central portion and the surface of said water.
4. A craft according to claim 1 wherein said air passage means extends internally of said hull central portion so that at least a longitudinally extending part of said air passage means is wholly defined by said hull central portion.
5. A craft according to claim 1 wherein said air passage means is provided with blower means for forcing air through said air passage means.
6. A craft according to claim 1 wherein a longitudinally forward part of said hull central portion is adapted to be in engagement with said water to support at least a portion of the weight of said craft.
7. A craft according to claim 1 wherein said aerodynamic lift surface is a continuously curved surface.
8. A craft according to claim 1 wherein said aerodynamic lift surface has a generally air foil-like cross-section.
9. A craft according to claim 1 wherein said aerodynamic lift surface is a concave surface for trapping air from said air passage means.
10. A craft according to claim 9 wherein said aerodynamic lift surface is a continuously curved surface.
11. A craft according to claim 10 wherein said aerodynamic lift surface has a generally air foil-like cross section.
12. A craft according to claim 11 wherein said concave surface has a substantially horizontally extending mid surface portion which smoothly merges with a downwardly and aftwardly extending aft surface portion.
13. A craft according to claim 12 wherein said aerodynamic lift surface has an upwardly and aftwardly extending forward surface portion which smoothly merges with said mid surface portion.
14. A craft according to claim 5 wherein said drive means is associated with said longitudinally forward part of said hull central portion.
15. A craft according to claim 1 wherein said air passage means includes at least two air passages, a first of said pair of air passages being provided by a forwardly opened part of said tunnel so that said first of said pair of air passages is at least partially defined by said hull central portion and a surface of said water, and a second of said pair of air passages extending internally of said hull central portion so that at least a part of said second of said pair of air passages is wholly defined by said hull central portion.
16. A craft according to claim 1 wherein said propulsion means provides a pair of drive means which are longitudinally spaced along said longitudinal axis of said craft with one of said drive means being located forwardly of said aerodynamic lifting surface.
17. A craft according to claim 1 further including a second generally downwardly facing aerodynamic lifting surface which defines at least a portion of said tunnel and which is configured to provide an upwardly acting aerodynamic force applied to said craft in response to a flow of air through said tunnel acting on said aerodynamic lifting surface to further reduce the water borne portion of the weight of said craft, said air passage means further supplying air which acts upon said second aerodynamic lifting surface to provide said aerodynamic force at said second aerodynamic lifting surface.
18. A craft according to claim 17 wherein said propulsion means provides a pair of drive means being longitudinally spaced along said longitudinal axis of said craft, one of said drive means being located forwardly of said first mentioned aerodynamic lifting surface and the second of said drive means being located forwardly of said second aerodynamic lifting surface.
19. A craft according to claim 14 wherein said longitudinally forward part of said hull central portion bifurcates said tunnel at the longitudinally forward part thereof.
1. A craft which is at least partially water borne and is adapted to be forwardly propelled along a longitudinal axis of the craft comprising:
2. A craft according to claim 1 wherein said tunnel substantially extends the full length of said craft.
3. A craft according to claim 1 wherein said tunnel is forwardly opened at least during propulsion of said craft to provide said air passage means with a longitudinally extending part of said air passage means being at least partially defined by said hull central portion and the surface of said water.
4. A craft according to claim 1 wherein said air passage means extends internally of said hull central portion so that at least a longitudinally extending part of said air passage means is wholly defined by said hull central portion.
5. A craft according to claim 1 wherein said air passage means is provided with blower means for forcing air through said air passage means.
6. A craft according to claim 1 wherein a longitudinally forward part of said hull central portion is adapted to be in engagement with said water to support at least a portion of the weight of said craft.
7. A craft according to claim 1 wherein said aerodynamic lift surface is a continuously curved surface.
8. A craft according to claim 1 wherein said aerodynamic lift surface has a generally air foil-like cross-section.
9. A craft according to claim 1 wherein said aerodynamic lift surface is a concave surface for trapping air from said air passage means.
10. A craft according to claim 9 wherein said aerodynamic lift surface is a continuously curved surface.
11. A craft according to claim 10 wherein said aerodynamic lift surface has a generally air foil-like cross section.
12. A craft according to claim 11 wherein said concave surface has a substantially horizontally extending mid surface portion which smoothly merges with a downwardly and aftwardly extending aft surface portion.
13. A craft according to claim 12 wherein said aerodynamic lift surface has an upwardly and aftwardly extending forward surface portion which smoothly merges with said mid surface portion.
14. A craft according to claim 5 wherein said drive means is associated with said longitudinally forward part of said hull central portion.
15. A craft according to claim 1 wherein said air passage means includes at least two air passages, a first of said pair of air passages being provided by a forwardly opened part of said tunnel so that said first of said pair of air passages is at least partially defined by said hull central portion and a surface of said water, and a second of said pair of air passages extending internally of said hull central portion so that at least a part of said second of said pair of air passages is wholly defined by said hull central portion.
16. A craft according to claim 1 wherein said propulsion means provides a pair of drive means which are longitudinally spaced along said longitudinal axis of said craft with one of said drive means being located forwardly of said aerodynamic lifting surface.
17. A craft according to claim 1 further including a second generally downwardly facing aerodynamic lifting surface which defines at least a portion of said tunnel and which is configured to provide an upwardly acting aerodynamic force applied to said craft in response to a flow of air through said tunnel acting on said aerodynamic lifting surface to further reduce the water borne portion of the weight of said craft, said air passage means further supplying air which acts upon said second aerodynamic lifting surface to provide said aerodynamic force at said second aerodynamic lifting surface.
18. A craft according to claim 17 wherein said propulsion means provides a pair of drive means being longitudinally spaced along said longitudinal axis of said craft, one of said drive means being located forwardly of said first mentioned aerodynamic lifting surface and the second of said drive means being located forwardly of said second aerodynamic lifting surface.
19. A craft according to claim 14 wherein said longitudinally forward part of said hull central portion bifurcates said tunnel at the longitudinally forward part thereof.
Description:
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to propelled watercraft, and particularly, to watercraft having longitudinally extending tunnels to effect an aerodynamic lifting force to reduce the weight of the craft which is borne by the water. The present invention provides an improved high speed watercraft which may be generally characterized as having a forward propulsion means in combination with a longitudinally extending tunnel having an aerodynamic lifting surface positioned aft of the propulsion means which is curvilinearly configured so as to trap and to be reacted on by air flowing through the tunnel to provide a generally upwardly acting lifting force which reduces the portion of the craft weight borne by the water. The basic design may be combined with blowers or the like for generating heated air which is directed at the lifting surface to increase the lifting forces generated at the surface. The combination of the front propulsion means with an aftwardly located lifting surface provides a craft of high maneuverability and stability, low drag, desirably reduces stern squat, and controls the pitch attitude of the craft so that it is positioned at an optimum level when planing. In a preferred construction of the lifting surface of the watercraft of this invention, an air foil-like lifting surface is utilized which may be characterized as having an upwardly and aftwardly extending forward surface portion, a generally horizontally extending mid surface portion, and a downwardly and aftwardly extending aft surface portion with each of the surface portions smoothly blending one into the other to provide a continuous curved surface. Preferably, the curved lifting surface is located at the mid portion of the watercraft while a generally horizontally oriented flat lifting surface may be located at the aft portion of the watercraft. In the preferred embodiment, the tunnel is bifurcated at its forward end by a central hull portion which conveniently serves as the passenger and cargo containing section of the watercraft.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a watercraft incorporating a hull configuration and propulsion means location according to the present invention;
FIG. 2 is a top view of the watercraft of FIG. 1;
FIG. 3 is a bottom view of the watercraft of FIG. 1;
FIG. 4 is a side cross-sectional view of the watercraft of FIG. 1;
FIG. 5 is a front view of the watercraft of FIG. 1;
FIG. 6 is an end cross-sectional view of the watercraft of FIG. 1; FIG. 7 is a partial rear view of the watercraft of FIG. 1; and
FIG. 8 is a side view of an alternative embodiment of the watercraft according to this invention having two lifting surfaces and three propelling means located in tandem along the longitudinal axis of the craft.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIGS. 1-7 a watercraft 10 is illustrated which includes a hull 12, a cabin 14 having a floor 15, and a propulsion means including a drive 16 which is located forward of the center line of the watercraft 10. The detailed construction of the cabin 14 forms no part of this invention, and accordingly, will not be described in detail.
The drive 16 may be an inboard/outboard drive unit having a propeller 18 for providing a reaction force in a well-known manner. The drive unit 16 may be pivotable about the vertical axis to provide a steering control for the craft in the well-known manner of inboard/outboard drives. The drive means 16 may be replaced by any other known drive means such as jet drive, fixed propeller with rudder, etc. Moreover, the propulsion means use any conventional engine such as internal combustion engine, turbine engine, steam engine, etc.
With particular reference now to FIGS. 3, 5 and 6, the hull can be seen to comprise a central portion 20 and a pair of side portions 22 and 24 respectively. Referring now to FIG. 3, the central hull portion 20 includes a forward portion including a passenger or cargo pod 26 which is adapted to engage the water, a curvilinear aerodynamic lift surface 28, and a flat lifting surface 30. It can be seen that the central hull portion 20 together with the side hull portions 22 and 24 and the surface of the water form a longitudinally extending tunnel which is bifurcated at its forward end by the forward central hull portion 26. In this regard, the hull is generally adapted to provide for a flow of air in the directions of the arrows 32.
Referring now to FIG. 4, the longitudinally extending tunnel has a generally horizontally disposed upper surface 36 which forms a tunnel entrance, the aforementioned lifting surface 28 comprising an upwardly and aftwardly extending surface portion 38, a generally horizontally extending surface portion 40, and a downwardly and aftwardly extending surface portion 42, and the generally horizontally extending aft surface 30. Each of the surfaces 30, 36-42 smoothly merge to form a continuous curvilinear surface. As can be seen in the drawings, the surfaces 38, 40 and 42 have a generally concave air foil-like cross section to receive and trap air flowing through the entrance 36. An aerodynamic lifting force generated at the lifting surface 28 acts generally in the direction indicated by arrows 46.
Referring now to FIG. 4, the location of the drive unit 16 with respect to the lifting surface 28 can be seen. Preferably, a motor 48 is mounted ahead of the drive unit 16 and is directly coupled to the drive unit 16 to rotate the propeller 18. It can be seen in FIG. 4 that the propeller 18 is located forward of the lifting surface 28.
As can be seen in FIG. 3, the side hull portions 22 and 24 are widely spaced to provide a high degree of lateral stability. Each side portion 22 and 24 is provided with a sharply angulated prow portion 60 which joins a generally horizontal planing surface 62. The planing surface 62 is provided with a keel-like projection 64 which provides directional stability when the craft is under way. A similar keel-like projection 66 is provided along the lifting surface 28 of the craft 10 for a similar purpose.
The engine 48 also drives a pair of laterally spaced blowers 50 (only one shown) which are connected to the engine by a suitable drive means 52. The blowers 50 are interposed in a pair of laterally spaced air passage 54 which is wholly within the forward hull central portion 20 having respective inlet openings 56 near the bow of the boat and respective outlet passages 58 communicating with the tunnel. The blower arrangement supplies air, heated by virtue of the compression effect, to the tunnel for reaction against the lifting surface 28 to augment the lift provided by the flow of air along the paths defined as arrows 32 due of the headway of the craft 10. Accordingly, there are two distinct air passages, one formed by the forward bifurcated part of the tunnel and the other formed within the forward hull central portion 26, supplying air to the lifting surface 28 to provide an aerodynamic lifting effect.
The craft 10 sits at rest with a water line as indicated in FIG. 1. The craft rises onto a plane, aided by the coaction of the forwardly located drive means 60 and the aerodynamic lift produced at the surface 28. It should also be noted that the combination of the forward located propulsion means 16 and the aftwardly located lifting surface 28 eliminates stern squat thereby enabling the boat to transition onto a plane with a substantially horizontal attitude. After the boat has reached a planing position, as indicated by the upper water line in FIG. 1, the forward mounted propulsion means 16 and the aftwardly located lifting surface 28 continue to coact to decrease drag and to provide enhanced maneuverability and stability.
The basic principle described with respect to the watercraft 10 in FIGS. 1-7 are generally applicable to any size craft and are readily susceptible to incorporation in larger craft wherein multiple propulsion means are desired. By way of illustration, a larger watercraft 68 is illustrated in FIG. 8 which incorporates three propulsion means 70, 72 and 74 which are located in tandem along the longitudinal center line of the craft 68, fore to aft respectively. The watercraft 68 includes a pair of lifting surfaces 76 and 78, respectively, each having associated lifting surface portions 80 and 82 which correspond to lifting surface surface portions 42 and 30 of the embodiment of FIGS. 1-7. The hull of the craft 68 has a pair of side portions 84 and a center portion 86 which together form a longitudinally extending tunnel communicating with lifting surfaces 76 and 78. The tunnel is bifurcated at the downwardly extending hull portions 88, 90 and 92. It will be appreciated that the longitudinally extending tunnel provides a flow of air to lifting surfaces 76 and 78 to provide an aerodynamic lifting force as described with respect to the embodiment of FIGS. 1-7. The lifting force provided by the flow of air through the longitudinally extending tunnel is augmented by forced air systems 94 and 96 for lifting surfaces 76 and 78, respectively. It will be appreciated that the craft 68 is but one modification of the basic concepts of this invention, and other combinations and modifications are possible within the scope of the teachings of the inventions.
The present invention relates to propelled watercraft, and particularly, to watercraft having longitudinally extending tunnels to effect an aerodynamic lifting force to reduce the weight of the craft which is borne by the water. The present invention provides an improved high speed watercraft which may be generally characterized as having a forward propulsion means in combination with a longitudinally extending tunnel having an aerodynamic lifting surface positioned aft of the propulsion means which is curvilinearly configured so as to trap and to be reacted on by air flowing through the tunnel to provide a generally upwardly acting lifting force which reduces the portion of the craft weight borne by the water. The basic design may be combined with blowers or the like for generating heated air which is directed at the lifting surface to increase the lifting forces generated at the surface. The combination of the front propulsion means with an aftwardly located lifting surface provides a craft of high maneuverability and stability, low drag, desirably reduces stern squat, and controls the pitch attitude of the craft so that it is positioned at an optimum level when planing. In a preferred construction of the lifting surface of the watercraft of this invention, an air foil-like lifting surface is utilized which may be characterized as having an upwardly and aftwardly extending forward surface portion, a generally horizontally extending mid surface portion, and a downwardly and aftwardly extending aft surface portion with each of the surface portions smoothly blending one into the other to provide a continuous curved surface. Preferably, the curved lifting surface is located at the mid portion of the watercraft while a generally horizontally oriented flat lifting surface may be located at the aft portion of the watercraft. In the preferred embodiment, the tunnel is bifurcated at its forward end by a central hull portion which conveniently serves as the passenger and cargo containing section of the watercraft.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a watercraft incorporating a hull configuration and propulsion means location according to the present invention;
FIG. 2 is a top view of the watercraft of FIG. 1;
FIG. 3 is a bottom view of the watercraft of FIG. 1;
FIG. 4 is a side cross-sectional view of the watercraft of FIG. 1;
FIG. 5 is a front view of the watercraft of FIG. 1;
FIG. 6 is an end cross-sectional view of the watercraft of FIG. 1; FIG. 7 is a partial rear view of the watercraft of FIG. 1; and
FIG. 8 is a side view of an alternative embodiment of the watercraft according to this invention having two lifting surfaces and three propelling means located in tandem along the longitudinal axis of the craft.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIGS. 1-7 a watercraft 10 is illustrated which includes a hull 12, a cabin 14 having a floor 15, and a propulsion means including a drive 16 which is located forward of the center line of the watercraft 10. The detailed construction of the cabin 14 forms no part of this invention, and accordingly, will not be described in detail.
The drive 16 may be an inboard/outboard drive unit having a propeller 18 for providing a reaction force in a well-known manner. The drive unit 16 may be pivotable about the vertical axis to provide a steering control for the craft in the well-known manner of inboard/outboard drives. The drive means 16 may be replaced by any other known drive means such as jet drive, fixed propeller with rudder, etc. Moreover, the propulsion means use any conventional engine such as internal combustion engine, turbine engine, steam engine, etc.
With particular reference now to FIGS. 3, 5 and 6, the hull can be seen to comprise a central portion 20 and a pair of side portions 22 and 24 respectively. Referring now to FIG. 3, the central hull portion 20 includes a forward portion including a passenger or cargo pod 26 which is adapted to engage the water, a curvilinear aerodynamic lift surface 28, and a flat lifting surface 30. It can be seen that the central hull portion 20 together with the side hull portions 22 and 24 and the surface of the water form a longitudinally extending tunnel which is bifurcated at its forward end by the forward central hull portion 26. In this regard, the hull is generally adapted to provide for a flow of air in the directions of the arrows 32.
Referring now to FIG. 4, the longitudinally extending tunnel has a generally horizontally disposed upper surface 36 which forms a tunnel entrance, the aforementioned lifting surface 28 comprising an upwardly and aftwardly extending surface portion 38, a generally horizontally extending surface portion 40, and a downwardly and aftwardly extending surface portion 42, and the generally horizontally extending aft surface 30. Each of the surfaces 30, 36-42 smoothly merge to form a continuous curvilinear surface. As can be seen in the drawings, the surfaces 38, 40 and 42 have a generally concave air foil-like cross section to receive and trap air flowing through the entrance 36. An aerodynamic lifting force generated at the lifting surface 28 acts generally in the direction indicated by arrows 46.
Referring now to FIG. 4, the location of the drive unit 16 with respect to the lifting surface 28 can be seen. Preferably, a motor 48 is mounted ahead of the drive unit 16 and is directly coupled to the drive unit 16 to rotate the propeller 18. It can be seen in FIG. 4 that the propeller 18 is located forward of the lifting surface 28.
As can be seen in FIG. 3, the side hull portions 22 and 24 are widely spaced to provide a high degree of lateral stability. Each side portion 22 and 24 is provided with a sharply angulated prow portion 60 which joins a generally horizontal planing surface 62. The planing surface 62 is provided with a keel-like projection 64 which provides directional stability when the craft is under way. A similar keel-like projection 66 is provided along the lifting surface 28 of the craft 10 for a similar purpose.
The engine 48 also drives a pair of laterally spaced blowers 50 (only one shown) which are connected to the engine by a suitable drive means 52. The blowers 50 are interposed in a pair of laterally spaced air passage 54 which is wholly within the forward hull central portion 20 having respective inlet openings 56 near the bow of the boat and respective outlet passages 58 communicating with the tunnel. The blower arrangement supplies air, heated by virtue of the compression effect, to the tunnel for reaction against the lifting surface 28 to augment the lift provided by the flow of air along the paths defined as arrows 32 due of the headway of the craft 10. Accordingly, there are two distinct air passages, one formed by the forward bifurcated part of the tunnel and the other formed within the forward hull central portion 26, supplying air to the lifting surface 28 to provide an aerodynamic lifting effect.
The craft 10 sits at rest with a water line as indicated in FIG. 1. The craft rises onto a plane, aided by the coaction of the forwardly located drive means 60 and the aerodynamic lift produced at the surface 28. It should also be noted that the combination of the forward located propulsion means 16 and the aftwardly located lifting surface 28 eliminates stern squat thereby enabling the boat to transition onto a plane with a substantially horizontal attitude. After the boat has reached a planing position, as indicated by the upper water line in FIG. 1, the forward mounted propulsion means 16 and the aftwardly located lifting surface 28 continue to coact to decrease drag and to provide enhanced maneuverability and stability.
The basic principle described with respect to the watercraft 10 in FIGS. 1-7 are generally applicable to any size craft and are readily susceptible to incorporation in larger craft wherein multiple propulsion means are desired. By way of illustration, a larger watercraft 68 is illustrated in FIG. 8 which incorporates three propulsion means 70, 72 and 74 which are located in tandem along the longitudinal center line of the craft 68, fore to aft respectively. The watercraft 68 includes a pair of lifting surfaces 76 and 78, respectively, each having associated lifting surface portions 80 and 82 which correspond to lifting surface surface portions 42 and 30 of the embodiment of FIGS. 1-7. The hull of the craft 68 has a pair of side portions 84 and a center portion 86 which together form a longitudinally extending tunnel communicating with lifting surfaces 76 and 78. The tunnel is bifurcated at the downwardly extending hull portions 88, 90 and 92. It will be appreciated that the longitudinally extending tunnel provides a flow of air to lifting surfaces 76 and 78 to provide an aerodynamic lifting force as described with respect to the embodiment of FIGS. 1-7. The lifting force provided by the flow of air through the longitudinally extending tunnel is augmented by forced air systems 94 and 96 for lifting surfaces 76 and 78, respectively. It will be appreciated that the craft 68 is but one modification of the basic concepts of this invention, and other combinations and modifications are possible within the scope of the teachings of the inventions.