CA1147212A - Rudder - Google Patents
RudderInfo
- Publication number
- CA1147212A CA1147212A CA000366847A CA366847A CA1147212A CA 1147212 A CA1147212 A CA 1147212A CA 000366847 A CA000366847 A CA 000366847A CA 366847 A CA366847 A CA 366847A CA 1147212 A CA1147212 A CA 1147212A
- Authority
- CA
- Canada
- Prior art keywords
- rudder
- drive
- steering
- boat
- axis
- 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.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H20/00—Outboard propulsion units, e.g. outboard motors or Z-drives; Arrangements thereof on vessels
- B63H20/32—Housings
- B63H20/34—Housings comprising stabilising fins, foils, anticavitation plates, splash plates, or rudders
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H25/00—Steering; Slowing-down otherwise than by use of propulsive elements; Dynamic anchoring, i.e. positioning vessels by means of main or auxiliary propulsive elements
- B63H25/06—Steering by rudders
- B63H25/38—Rudders
- B63H25/382—Rudders movable otherwise than for steering purposes; Changing geometry
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- Ocean & Marine Engineering (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The present invention provides, in combination, a drive for a boat of the outboard or inboard/outboard type, said drive having a propulsion means for producing a slipstream as it moves through the water; the drive being turnable about a steering axis to provide a steering effect on the boat, and a rudder to assist in steering the boat at speeds below a selected speed. A mechanical coupling connects said rudder directly to said drive so that both the drive and the rudder turn together about said steering axis as the boat is steered. The mechanical coupling between said rudder and said drive includes means defining a pivot axis generally transverse to said steering axis permitting the rudder to pivot relative to said drive between a lowered position where the rudder can react to the slipstream of the propulsion means and a raised position where said rudder is substantially removed from the slipstream. The pivot axis is located relative to the rudder such that forces acting on said rudder in its lowered position by virtue of the motion of water relative thereto provide a moment about said axis capable of pivoting the rudder about said axis and moving same toward the raised position as the relative speed between the water and the rudder approaches a predetermined value to make the steering of the boat substantially independent of the rudder.
The present invention provides, in combination, a drive for a boat of the outboard or inboard/outboard type, said drive having a propulsion means for producing a slipstream as it moves through the water; the drive being turnable about a steering axis to provide a steering effect on the boat, and a rudder to assist in steering the boat at speeds below a selected speed. A mechanical coupling connects said rudder directly to said drive so that both the drive and the rudder turn together about said steering axis as the boat is steered. The mechanical coupling between said rudder and said drive includes means defining a pivot axis generally transverse to said steering axis permitting the rudder to pivot relative to said drive between a lowered position where the rudder can react to the slipstream of the propulsion means and a raised position where said rudder is substantially removed from the slipstream. The pivot axis is located relative to the rudder such that forces acting on said rudder in its lowered position by virtue of the motion of water relative thereto provide a moment about said axis capable of pivoting the rudder about said axis and moving same toward the raised position as the relative speed between the water and the rudder approaches a predetermined value to make the steering of the boat substantially independent of the rudder.
Description
Z
BACKGROU~D OF THE -~NVEN~ION
This invention relates to a steering aid for o~ltboard motors and inboard/outboard drives wherein the slipstream of the propeller acts to provide a steering effect on the boat.
It is well known that as long as the propeller runs at a relatively high speed, a sufficient slipstream is provided to give steerage to the boat. However, once the speed of the motor is reduced, the slipstream is also reduced and conse~uently the steering of the boat becomes less responsive ~ 10 and more difficult.
There is accordingly a need for a system which will allow the operator of a boat to control and manoeuver the boat safely at slow speeds and also to allow the user to keep the - boat on a steady and positive course. There is a need to 15 provide boaters with positive and safe steering while trolling or manoeuvering in and out of tight harbour areas at slow speeds.
The prior art has provided various forms of fixed rudder arrangements involving the use of a rudder plate located 20 rearwardly of the propeller in a position to react with the - propel'er slipstream. The problem associated with the fixed rudder construction is that the steering force becomes overly large at high speeds. The fixed rudder usually causes the - boat to oversteer at high speeds and in extreme cases the 25 boat could be made to capsize.
In an effort to overcome the disadvantage of the fixed rudder blade arrangements, the prior art has provided means for lifting the rudder vertically upwardly ~s '~e h ~ r ~ ~ ~ 2. C h ? ~-'7~
a predetermined speed thereby to achieve the advantage of theauxiliary rudder at iow sped while avoiding its disadvantage at higher speeds. One such arrangement is shown in Canadian patent number l,001,904 issued 76/12/~1 to Wasenius. In the 5 arrangement shown in this patent, a bracket is connected to the anti-cavitation plate of an outboard motor, such bracket including a pair of spaced parallel steering rods. A rudder is mounted for vertical sliding motion along these parallel rods and the lower end of the rudder is provided with adjustable 10 hGrizontally disposed fins which exert a lifting force on the rudder as the speed of travel through the water increases. The difficulty with this arrangement resides in its complexity and attendant cost as well as its dependence on the abilit~ of the rudder to slide freely along the vertically disposed rods.
15 Any obstruction preventing the free sliding movement of the rudder in the vertical direction will impair or completely destroy the capability of the device to function. In systems of this general nature, marine deposits and/or corrosion can pose a serious problem and hence there is a need to 20 provide an alternative form of system which avoids the disadvantages of the apparatus briefly described above.
S~MMARY OF THE INVENTION
It is a general object of the present invention to provide a very simple yet effective rudder arrangement for use 25 on boat drives of the outboard or inboard/outboard type, which rudder arrangement is so arranged as to pivot upwardly and be raised out of the water automatically to avoid over-steering at higher speeds with such rudder automatically ; lowering downwardly toward its lower position as the boat 30 slows down thereby to provide for more positive steerlng at :, slow speeds.
It is a further object of the present irvention to provide a rudder arrangement which li~ts upwardly at higher speeds and which at the same time avoids the use of slidable S mounting arran~ements for the rudder which could become fouled by v~rious deposits, and which rudder arrangement is extremely simple and thus relatively cheap to manufacture.
Accordingly, the present invention in one aspect provides in combination, a drive for a boat of the outboard or 10 inboard/outboard type, said drive having a propulsion means for producins a slipstream as it moves through the water;
the drive being turnable ahout a steering axis to prcvide a steering effect on the boat, and a rudder to assist in steering the boat at speeds below a selected speed. A mechanical 15 coupling connects said rudder directly to said drive so that both the drive and the rudder turn together about said steering axis as the boat is steered. The mechanical coupling between said rudder and said drive includes means defining a pivot axis generally transverse to said steering axis 20 permitting the rudder to pivot relative tc said drive between a lowered position where the rudder can react to the slipstream of the propulsion means and a raised position where said rudder is substantially removed from the slipstream. The pivot axis is located relative to the rudder such that forces acting on ' 25 said rudder in its lowered position by virtue of the motion of water relative thereto provide a moment about said axis capable of pivoting the rudder about said axis and moving same toward the raised position as the relative speed between the water and the rudder approaches a predetermined value to make -the 30 steerin~ of the boat substantially independent of the rudder.
The rudder may cor.lprise a simple generally flat plate.
The above-noted mechanical coupling preferably includes arms connected to the plate, with such arms having free end portions remote from the plate with said means defining the pivot axis 5 being located at the free ends of the arms.
The arms are preferably connected adjacent an upper end portion of the rudder plate, with such arms being made so that they diverge away from one another toward thelr free outer ends to e~brace a portion of the drive therebetween. The 10 pivot axis defining means may include brackets secured to the drive above the propulsion means with the brac~ets being pivotally secured to the free end portions of the ~rms. In a typiczl embodiment these brackets are secured to the anti-cavitation plate of the outboard drive.
In drawings which illustrate an embodiment of the invention:
Fig. 1 is a side elevation view of a lower end portion of an outboard drive showing a rudder arrangement according to 20 the invention connected thereto with raised positions of the rudder being shown in phantom;
Fig. 2 is a rear end elevation view of the outboard drive of Fig. 1 showing the rudder arrangement in its lowered position;
Fig. 3 is a top plan view of the rudder arrangement per se;and, Fig. 4 is a ~rasmentary section view taken along line 4-4 of Fig. 1.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
- 30 Referring now to the drawings, there is illustrated a lower end ~ortion of a drive 10 of an outboard motor, it '7~
being realized that the drive can also be of the inboard/
outboard type. The outboard drive can be of any commercially available type, such drive including a propeller 12 which produces a slipstream during movement through the water in the 5 usual fashion. The drive unit 10 also includes the usual anti-cavitation plate 14 disposed immediately above the propeller 12. The entire outboard drive 10 is turnable about a steering axis S-S as illustrated in Fig. 1 to provide a steering effect on the boat in the manner well known in the art.
A rudder 16 is provided to assist in assist in steering the boat at speeds below a selected speed. A
mechanical coupling broadly designated by reference numeral 18 connects rudder 16 directly to the drive 10 so that both the drive 10 and the rudder 16 turn together about the steering lS axis S-S as the boat ls steered. Mechanical coupling 18 between the rudder 16 and drive 10 includes means defining a ; pivot axis P-P generally transverse to the steering axis S-S
to permit the rudder 16 to pivot relative to the drive 10 between a lowered position (shown in full lines in Fig. 1) 20 where the rudder 16 can react to the slipstream of the propeller 12, and a raised position A (shown in phantom in Fig. 1) wherein the rudder 16 is substantially removed from the slipstream. This pivot axis P-P is located relative to the rudder 16 s-uch that the forces acting on the rudder in its 25 lowered position by virtue of the motion of water relative thereto provide a turning moment about axis P-P capable of pivoting rudder 16 about such axis and moving same toward the raised position A as the relative speed between the water and the rudder approaches a predetermined value (e.g. about 10 30 knots) to make the steering of the boat substantially 7~
' independent of the rudder and thus avoid problems of over-steering etc.
It will be seen from Figs~ l and 2 that the rudder comprises a simple flat plate while the mechanical coupling 18 5includes a pair of arms 20 which are connected to opposing sides of the uppermost end of the rudder plate by rivets 22.
The arms 20 diverse away from each other toward their free outer ends so as to embrace a portion of the drive 10 there-between. The means defining the pivot axis P-P include angle lObrackets 24 c3nnected by fasteners 26 to the cavitation plate 14. Machine bolts 28 serve to secure the free ends of arms 20 to the angle brackets 24 with suitable nylon inserts and washers 30 being provided to reduce friction between arms 20 and angle brackets 24 thereby to ensure free pivotal movement 15Of rudder 16 about pivot axis P-P.
The rudder 16 is preferably made from a high tensile strength aluminum having suitable corrosion resistant properties with the entire rudder a~sembly including arms 2C
preferably being anodized ln a suitable colour, such as black 20 or silver, to further enhance the appearance and to protect the assembly from corrosion. The rudder assembly may be quickly and readily attached to an existing outboard drive simply by drilling a pair of small holes in the anti-cavitation plate thereby to allow for attachment of the above-noted angle 25 brackets 24.
~ he manner in which the rudder arrangement functions will be readily apparent to those skilled in the art. At low speeds, such as when one is trolling or moving into or out of close harbour areas, the rudder 16 will be located in the 30 lower full line position shown in Fig. 1. In this condition, :
.
~l47Z~
the rudder 16 exerts a very positive steering effect due to the fact that it is in a position where it can react to the propeller slipstream. As the propeller speeds up however, and the force of the propeller slipstream becomes greater, the 5 relative speed between the water and the rudder increases thus increasing the friction forces between the water and the rudder.
Due to the fact that the pivot a~is P-P is located generally at the level of the uppermost end of the rudder 15, and well above the center line of the propeller, these friction forces exerted 10 on the rudder tend to create a turning moment about pivot axis P-~ thus tending to cause the rudder 16 to tilt or rotate clockwise as shown in Fig. 1 toward the raised position A. Thus, as the relative speed between the water and the rudder surfaces ~` increases, the rudder tends to be lifted higher and higher out - 15 of the water until an equilibrium position is ~eached, i.e.
a position wherein ~he downwardly acting forces of gravity on the rudder balance the oppositely directed turning moments of force exerted by the water acting on the rudder surfaces. It is believed that persons skilled in the art will have no d fficulty 20 in providing a rudder of a suitable size as to accomplish the above effect.
Two basic rudder sizes will suffice for use with motors in the 2 to 200 horsepower range, the smaller rudder being used for the lower horsepower range and the larger rudder for the upper half of the horsepower range. sy way of example these two basic sizes had the following approximate dimensions, reference being had to Fig. 1:
1~7~212 Small Rudder Large Rudder Rudder height 30 cm 45 cm Rudder width 10 cm 10 cm Arm length (~ 18.5 cm 18.5 cm Thickness ~rudder plate)3.5 mm 3.5 mm A typical rudder constructed as above will begin to lift out of the water between 6 and 8 knots and at somewhere between 10 and 15 knots the rudder will be substantially out of the water. ~he rudder will never clear the water entirely 10 however and even at high speed as much as 10 to 1~ percent of the rudder will be immersed.
It will be appreciated that the above dimensions are not critical and that those skilled in the art will be able to select other suitable combinatlons of dimensions to adapt the tiltable rudder system to various types of outboard and ;~ inboard/outboard drives. In the example given above, the rudder plate and the arms 20 were made of high tensile strength - aluminum.
It will be appreciated that the foregoing 20 description is for illustrative purposes only and that various changes and modifications can be made within the scope of the invention. Accordingly, the present specification is not to be limited by the foregoing illustrative example, but only by the scope of the claims appended hereto.
.,
BACKGROU~D OF THE -~NVEN~ION
This invention relates to a steering aid for o~ltboard motors and inboard/outboard drives wherein the slipstream of the propeller acts to provide a steering effect on the boat.
It is well known that as long as the propeller runs at a relatively high speed, a sufficient slipstream is provided to give steerage to the boat. However, once the speed of the motor is reduced, the slipstream is also reduced and conse~uently the steering of the boat becomes less responsive ~ 10 and more difficult.
There is accordingly a need for a system which will allow the operator of a boat to control and manoeuver the boat safely at slow speeds and also to allow the user to keep the - boat on a steady and positive course. There is a need to 15 provide boaters with positive and safe steering while trolling or manoeuvering in and out of tight harbour areas at slow speeds.
The prior art has provided various forms of fixed rudder arrangements involving the use of a rudder plate located 20 rearwardly of the propeller in a position to react with the - propel'er slipstream. The problem associated with the fixed rudder construction is that the steering force becomes overly large at high speeds. The fixed rudder usually causes the - boat to oversteer at high speeds and in extreme cases the 25 boat could be made to capsize.
In an effort to overcome the disadvantage of the fixed rudder blade arrangements, the prior art has provided means for lifting the rudder vertically upwardly ~s '~e h ~ r ~ ~ ~ 2. C h ? ~-'7~
a predetermined speed thereby to achieve the advantage of theauxiliary rudder at iow sped while avoiding its disadvantage at higher speeds. One such arrangement is shown in Canadian patent number l,001,904 issued 76/12/~1 to Wasenius. In the 5 arrangement shown in this patent, a bracket is connected to the anti-cavitation plate of an outboard motor, such bracket including a pair of spaced parallel steering rods. A rudder is mounted for vertical sliding motion along these parallel rods and the lower end of the rudder is provided with adjustable 10 hGrizontally disposed fins which exert a lifting force on the rudder as the speed of travel through the water increases. The difficulty with this arrangement resides in its complexity and attendant cost as well as its dependence on the abilit~ of the rudder to slide freely along the vertically disposed rods.
15 Any obstruction preventing the free sliding movement of the rudder in the vertical direction will impair or completely destroy the capability of the device to function. In systems of this general nature, marine deposits and/or corrosion can pose a serious problem and hence there is a need to 20 provide an alternative form of system which avoids the disadvantages of the apparatus briefly described above.
S~MMARY OF THE INVENTION
It is a general object of the present invention to provide a very simple yet effective rudder arrangement for use 25 on boat drives of the outboard or inboard/outboard type, which rudder arrangement is so arranged as to pivot upwardly and be raised out of the water automatically to avoid over-steering at higher speeds with such rudder automatically ; lowering downwardly toward its lower position as the boat 30 slows down thereby to provide for more positive steerlng at :, slow speeds.
It is a further object of the present irvention to provide a rudder arrangement which li~ts upwardly at higher speeds and which at the same time avoids the use of slidable S mounting arran~ements for the rudder which could become fouled by v~rious deposits, and which rudder arrangement is extremely simple and thus relatively cheap to manufacture.
Accordingly, the present invention in one aspect provides in combination, a drive for a boat of the outboard or 10 inboard/outboard type, said drive having a propulsion means for producins a slipstream as it moves through the water;
the drive being turnable ahout a steering axis to prcvide a steering effect on the boat, and a rudder to assist in steering the boat at speeds below a selected speed. A mechanical 15 coupling connects said rudder directly to said drive so that both the drive and the rudder turn together about said steering axis as the boat is steered. The mechanical coupling between said rudder and said drive includes means defining a pivot axis generally transverse to said steering axis 20 permitting the rudder to pivot relative tc said drive between a lowered position where the rudder can react to the slipstream of the propulsion means and a raised position where said rudder is substantially removed from the slipstream. The pivot axis is located relative to the rudder such that forces acting on ' 25 said rudder in its lowered position by virtue of the motion of water relative thereto provide a moment about said axis capable of pivoting the rudder about said axis and moving same toward the raised position as the relative speed between the water and the rudder approaches a predetermined value to make -the 30 steerin~ of the boat substantially independent of the rudder.
The rudder may cor.lprise a simple generally flat plate.
The above-noted mechanical coupling preferably includes arms connected to the plate, with such arms having free end portions remote from the plate with said means defining the pivot axis 5 being located at the free ends of the arms.
The arms are preferably connected adjacent an upper end portion of the rudder plate, with such arms being made so that they diverge away from one another toward thelr free outer ends to e~brace a portion of the drive therebetween. The 10 pivot axis defining means may include brackets secured to the drive above the propulsion means with the brac~ets being pivotally secured to the free end portions of the ~rms. In a typiczl embodiment these brackets are secured to the anti-cavitation plate of the outboard drive.
In drawings which illustrate an embodiment of the invention:
Fig. 1 is a side elevation view of a lower end portion of an outboard drive showing a rudder arrangement according to 20 the invention connected thereto with raised positions of the rudder being shown in phantom;
Fig. 2 is a rear end elevation view of the outboard drive of Fig. 1 showing the rudder arrangement in its lowered position;
Fig. 3 is a top plan view of the rudder arrangement per se;and, Fig. 4 is a ~rasmentary section view taken along line 4-4 of Fig. 1.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
- 30 Referring now to the drawings, there is illustrated a lower end ~ortion of a drive 10 of an outboard motor, it '7~
being realized that the drive can also be of the inboard/
outboard type. The outboard drive can be of any commercially available type, such drive including a propeller 12 which produces a slipstream during movement through the water in the 5 usual fashion. The drive unit 10 also includes the usual anti-cavitation plate 14 disposed immediately above the propeller 12. The entire outboard drive 10 is turnable about a steering axis S-S as illustrated in Fig. 1 to provide a steering effect on the boat in the manner well known in the art.
A rudder 16 is provided to assist in assist in steering the boat at speeds below a selected speed. A
mechanical coupling broadly designated by reference numeral 18 connects rudder 16 directly to the drive 10 so that both the drive 10 and the rudder 16 turn together about the steering lS axis S-S as the boat ls steered. Mechanical coupling 18 between the rudder 16 and drive 10 includes means defining a ; pivot axis P-P generally transverse to the steering axis S-S
to permit the rudder 16 to pivot relative to the drive 10 between a lowered position (shown in full lines in Fig. 1) 20 where the rudder 16 can react to the slipstream of the propeller 12, and a raised position A (shown in phantom in Fig. 1) wherein the rudder 16 is substantially removed from the slipstream. This pivot axis P-P is located relative to the rudder 16 s-uch that the forces acting on the rudder in its 25 lowered position by virtue of the motion of water relative thereto provide a turning moment about axis P-P capable of pivoting rudder 16 about such axis and moving same toward the raised position A as the relative speed between the water and the rudder approaches a predetermined value (e.g. about 10 30 knots) to make the steering of the boat substantially 7~
' independent of the rudder and thus avoid problems of over-steering etc.
It will be seen from Figs~ l and 2 that the rudder comprises a simple flat plate while the mechanical coupling 18 5includes a pair of arms 20 which are connected to opposing sides of the uppermost end of the rudder plate by rivets 22.
The arms 20 diverse away from each other toward their free outer ends so as to embrace a portion of the drive 10 there-between. The means defining the pivot axis P-P include angle lObrackets 24 c3nnected by fasteners 26 to the cavitation plate 14. Machine bolts 28 serve to secure the free ends of arms 20 to the angle brackets 24 with suitable nylon inserts and washers 30 being provided to reduce friction between arms 20 and angle brackets 24 thereby to ensure free pivotal movement 15Of rudder 16 about pivot axis P-P.
The rudder 16 is preferably made from a high tensile strength aluminum having suitable corrosion resistant properties with the entire rudder a~sembly including arms 2C
preferably being anodized ln a suitable colour, such as black 20 or silver, to further enhance the appearance and to protect the assembly from corrosion. The rudder assembly may be quickly and readily attached to an existing outboard drive simply by drilling a pair of small holes in the anti-cavitation plate thereby to allow for attachment of the above-noted angle 25 brackets 24.
~ he manner in which the rudder arrangement functions will be readily apparent to those skilled in the art. At low speeds, such as when one is trolling or moving into or out of close harbour areas, the rudder 16 will be located in the 30 lower full line position shown in Fig. 1. In this condition, :
.
~l47Z~
the rudder 16 exerts a very positive steering effect due to the fact that it is in a position where it can react to the propeller slipstream. As the propeller speeds up however, and the force of the propeller slipstream becomes greater, the 5 relative speed between the water and the rudder increases thus increasing the friction forces between the water and the rudder.
Due to the fact that the pivot a~is P-P is located generally at the level of the uppermost end of the rudder 15, and well above the center line of the propeller, these friction forces exerted 10 on the rudder tend to create a turning moment about pivot axis P-~ thus tending to cause the rudder 16 to tilt or rotate clockwise as shown in Fig. 1 toward the raised position A. Thus, as the relative speed between the water and the rudder surfaces ~` increases, the rudder tends to be lifted higher and higher out - 15 of the water until an equilibrium position is ~eached, i.e.
a position wherein ~he downwardly acting forces of gravity on the rudder balance the oppositely directed turning moments of force exerted by the water acting on the rudder surfaces. It is believed that persons skilled in the art will have no d fficulty 20 in providing a rudder of a suitable size as to accomplish the above effect.
Two basic rudder sizes will suffice for use with motors in the 2 to 200 horsepower range, the smaller rudder being used for the lower horsepower range and the larger rudder for the upper half of the horsepower range. sy way of example these two basic sizes had the following approximate dimensions, reference being had to Fig. 1:
1~7~212 Small Rudder Large Rudder Rudder height 30 cm 45 cm Rudder width 10 cm 10 cm Arm length (~ 18.5 cm 18.5 cm Thickness ~rudder plate)3.5 mm 3.5 mm A typical rudder constructed as above will begin to lift out of the water between 6 and 8 knots and at somewhere between 10 and 15 knots the rudder will be substantially out of the water. ~he rudder will never clear the water entirely 10 however and even at high speed as much as 10 to 1~ percent of the rudder will be immersed.
It will be appreciated that the above dimensions are not critical and that those skilled in the art will be able to select other suitable combinatlons of dimensions to adapt the tiltable rudder system to various types of outboard and ;~ inboard/outboard drives. In the example given above, the rudder plate and the arms 20 were made of high tensile strength - aluminum.
It will be appreciated that the foregoing 20 description is for illustrative purposes only and that various changes and modifications can be made within the scope of the invention. Accordingly, the present specification is not to be limited by the foregoing illustrative example, but only by the scope of the claims appended hereto.
.,
Claims (5)
1. In combination, a drive for a boat of the outboard or inboard/outboard type, said drive having a propulsion means for producing a slipstream as it moves through the water;
the drive being turnable about a steering axis to provide a steering effect on the boat, and a rudder to assist in steering the boat at speeds below a selected speed, a mechanical coupling connecting said rudder directly to said drive so that both the drive and the rudder turn together about said steering axis as the boat is steered; wherein the mechanical coupling between said rudder and said drive includes means defining a pivot axis generally transverse to said steering axis permitting the rudder to pivot relative to said drive between a lowered position where the rudder can react to the slipstream of the propulsion means and a raised position where said rudder is substantially removed from the slipstream, said pivot axis being located relative to the rudder such that forces acting on said rudder in its lowered position by virtue of the motion of water relative thereto provide a moment about said axis capable of pivoting the rudder about said axis and moving same toward the raised position as the relative speed between the water and the rudder approaches a predetermined value to make the steering of the boat substantially independent of the rudder.
the drive being turnable about a steering axis to provide a steering effect on the boat, and a rudder to assist in steering the boat at speeds below a selected speed, a mechanical coupling connecting said rudder directly to said drive so that both the drive and the rudder turn together about said steering axis as the boat is steered; wherein the mechanical coupling between said rudder and said drive includes means defining a pivot axis generally transverse to said steering axis permitting the rudder to pivot relative to said drive between a lowered position where the rudder can react to the slipstream of the propulsion means and a raised position where said rudder is substantially removed from the slipstream, said pivot axis being located relative to the rudder such that forces acting on said rudder in its lowered position by virtue of the motion of water relative thereto provide a moment about said axis capable of pivoting the rudder about said axis and moving same toward the raised position as the relative speed between the water and the rudder approaches a predetermined value to make the steering of the boat substantially independent of the rudder.
2. The combination according to claim 1 wherein said rudder comprises generally flat plate means, the pivot axis being located generally above said propulsion means.
3. The combination according to claim 1 wherein said rudder comprises a generally flat plate, and said mechanical coupling comprises arm means connected to said plate, the arm means having free end portions remote from said plate and the means defining the pivot axis being at said free end portions.
4. The combination according to claim 3 wherein said arm means are connected adjacent an end portion of said plate with the arm means diverging away from each other toward their free outer ends to embrace a portion of the drive therebetween, the means defining the pivot axis including brackets secured to the drive above the propulsion means and to said free end portions of the arms.
5. The combination according to claim 4 wherein said drive includes an anti-cavitation plate located above said propulsion means with said brackets being secured to said anti-cavitation plate.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA000366847A CA1147212A (en) | 1980-12-16 | 1980-12-16 | Rudder |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA000366847A CA1147212A (en) | 1980-12-16 | 1980-12-16 | Rudder |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1147212A true CA1147212A (en) | 1983-05-31 |
Family
ID=4118710
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000366847A Expired CA1147212A (en) | 1980-12-16 | 1980-12-16 | Rudder |
Country Status (1)
Country | Link |
---|---|
CA (1) | CA1147212A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4556006A (en) * | 1983-06-24 | 1985-12-03 | Kaupat Peter H | Kayak steering system |
-
1980
- 1980-12-16 CA CA000366847A patent/CA1147212A/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4556006A (en) * | 1983-06-24 | 1985-12-03 | Kaupat Peter H | Kayak steering system |
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