GB2161441A - Hydrofoil steering mechanism - Google Patents
Hydrofoil steering mechanism Download PDFInfo
- Publication number
- GB2161441A GB2161441A GB08517517A GB8517517A GB2161441A GB 2161441 A GB2161441 A GB 2161441A GB 08517517 A GB08517517 A GB 08517517A GB 8517517 A GB8517517 A GB 8517517A GB 2161441 A GB2161441 A GB 2161441A
- Authority
- GB
- United Kingdom
- Prior art keywords
- steering
- hydrofoils
- arm
- hydrofoil
- rods
- 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.)
- Granted
Links
Classifications
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING
- B63B1/00—Hydrodynamic or hydrostatic features of hulls or of hydrofoils
- B63B1/16—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving additional lift from hydrodynamic forces
- B63B1/24—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving additional lift from hydrodynamic forces of hydrofoil type
- B63B1/28—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving additional lift from hydrodynamic forces of hydrofoil type with movable hydrofoils
- B63B1/283—Hydrodynamic or hydrostatic features of hulls or of hydrofoils deriving additional lift from hydrodynamic forces of hydrofoil type with movable hydrofoils movable around a vertical axis, e.g. for steering
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- Ocean & Marine Engineering (AREA)
- Steering-Linkage Mechanisms And Four-Wheel Steering (AREA)
Abstract
Hydrofoils 1 have stub axes 3 which rotate in hubs 4 fixed to the stern of a boat 2, in an inverted V arrangement with the axes of rotation at an angle which preferably lies between 101 DEG and 79 DEG . Each stub axle 3 is fitted with a crank arm 6 connected by a steering push rod 5 to a steering arm 7 pivoted at 9. The rods 5 are connected to the arm 7 by pivot joints 8 which are slightly offset to the rear of the pivot 9. Steering forces are applied to the arm 7 by cables or rods 10 controlled by a steering wheel, and movement of the steering arm 7 rotates the hydrofoils 1 in the same direction, so as to modify their angles of attack and creating an angle of attack differential between the two, thus inducing a steering force. The offset between the pivot points 8 and the pivot 9 renders the differential of the angle of attack non-linear so that each hydrofoil 1 describes the correct circle about a common centre of turn. <IMAGE>
Description
SPECIFICATION
Hydrofoil steering mechanism
This invention relates generally to hydrofoil boats and more particularly to steering mechanism for such boats. The terms "hydrofoil boat" or "hydrofoil assisted boat" are used to describe boats or similar vessels which use lifting forces produced by the flow of water over lifting surfaces to reduce the drag of the boat by raising the boat partially or completely
out of the water.
Hydrofoil assisted boats are generally steered by
either a "T" hydrofoil or a box hydrofoil. These systems of steering and other similar systems either
require continual adjustment as speeds vary or
produce excessively heavy load imbalance on the
steering mechanism when wave action is encountered.
According to the present invention, hydrofoil
steering mechanism comprises a pair of similar
hydrofoils in inverted-V arrangement mounted for
rotation about their respective axes so as to adjust the angle to attack and a common linkage connected to both hydrofoils for turning them in the samedirection under the control of a steering member.
The advantage of such an arrangement is that, as the
boat rises with speed, all foils reduce in area and thereby retain lift stability, thus avoiding the need for the continual adjustment required with other systems.
Generally speaking, the hydrofoils will be straight,
but this is not essential. In any case, whatever the shape of the hydrofoils, the V is defined between the two axes of rotation and its angle is preferably
between 101" and 79O.
The linkage for turning the two hydrofoils prefer
ably comprises a laterally extending pivoted steering
arm turned by the steering member and connected
on opposite lateral sides of its pivot by rods to crank arms extending from respective stub axles for the
hydrofoils. As the steering arm is turned about its
pivot by the steering member, one end moves forwardly to transmit a similar movement to the rod
on that side, and the other end moves aft, also to transmit a similar movement to the rod on that side, the crank arms extending from the stub axles for the
hydrofoil thus requiring to extend laterally in oppo
site directions so that these two opposite move
ments cause the two hydrofoils to turn in the same
angular direction.This turning movement modifies -the angle of attack of each hydrofoil, thus creating an
angle of attack differential between the two and thereby inducing a steering force.
As the boat turns as a result of the induced
steering force, the two hydrofoils each move in a circular arc about a common centre of turn. The
hydrofoil further from the centre of turn follows a
somewhat greater radius than the other hydrofoil
and should therefore be turned through a very
slightly smaller angle than the other. For this
purpose the connection points of the rods to the
steering arm may be offset rearwardlyfrom the pivot
of the arm, thereby introducing a small differential
into the movement of the rods and hence a corresponding small differential in the turning movement of the two hydrofoils.
The steering arm will normally be controlled by a steering wheel, the motion being transmitted to the arm by cables or rods connected to it in the region of its outer ends. Alternatively, these cables or rods may be controlled by a tiller or similar form of steering member.
An example of steering mechanism in accordance with the invention will now be described with reference to the accompanying drawings, in which:
Figure 1 is a perspective view of the mechanism attached to the stern of a boat; and
Figure 2 is a plan view of the mechanism of Figure 1 adjusted to its central position.
The mechanism comprises a pair of hydrofoils 1 which, as best seen from Figure 1, are mounted in an inverted-V arrangement, the angle of the V (i.e. the angle between the axes of rotation) being shown as 0. The size of this angle will depend to a certain extent on the size and other characteristics of the boat to which the mechanism is fitted, but in general will lie between 112" and 68 , preferably between 101" and 79". In a particular example, this angle may be 90".
The hydrofoils 1 have stub axles 3 which rotate in bearing hubs 4 fixed to the stern of the boat 2. As shown in Figure 2, the steering mechanism is in its central position so that the horizontal components of the thrust exerted on the hydrofoils 1 cancel one another and produce no steering force, while the vertical components combine to produce a lifting force. When the hydrofoils 1 are turned in the same angular direction from the central position shown in
Figure 2, the horizontal components no longer cancel one another and a side-ways steering force is produced while the vertical lift is maintained.
To produce the necessary turning movement, each stub axle 3 is fitted with a crank arm 6 having a pivotal connection to corresponding steering push rods 5 which, at their other ends, are connected by similar pivotal connections 8to a steering arm 7 which is pivoted about a spindle 9. Steering forces are applied to the ends of the arm 7 via cables or push rods 10 which, in their turn, may be controlled by a steering wheel ortiller arrangement (not shown). Turning movements of the arm 7 are transmitted via the rods 5 to the crank arms 6 and hence to the hydrofoils 1 which are thereby caused to turn in the same angular direction, their respective angles of attack thereby being modified to create a differential between the two, thus inducing a steering force as previously described.
The pivotal connections 8 between the rods 5 and the steering arm 7 are offset rearwardly from the pivot line of the arm 7 buy a distance shown as 12, thus rendering the differential of the angles of attack non-linear and causing each hydrofoil 1 to described the correct circle about a common centre of turn, as previously described.
1. Hydrofoil steering mechanism comprising a pair of similar hydrofoils in inverted-V arrangement
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (4)
1. Hydrofoil steering mechanism comprising a pair of similar hydrofoils in inverted-V arrangement mounted for rotation about their respective axes so as to adjust the angle of attack and a common linkage connected to both hydrofoilsforturning them in the same direction under the control of a steering member.
2. Mechanism according to claim 1 in which the linkage comprises a laterally extending pivoted steering arm turned by the steering member and connected on opposite lateral sides of its pivot by rods to crank arms extending from respective stub axles for the hydrofoils.
3. Mechanism according to claim 2, in which the connection points of the rods of the steering arm are offset rearwrdly from the pivot of the arm.
4. Mechanism according to claim 2 or claim 3, in which the steering arm is turned by cables or rods connected to it in the region of its outer ends.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB848417939A GB8417939D0 (en) | 1984-07-13 | 1984-07-13 | Steering hydrofoil |
Publications (3)
Publication Number | Publication Date |
---|---|
GB8517517D0 GB8517517D0 (en) | 1985-08-14 |
GB2161441A true GB2161441A (en) | 1986-01-15 |
GB2161441B GB2161441B (en) | 1987-10-14 |
Family
ID=10563871
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB848417939A Pending GB8417939D0 (en) | 1984-07-13 | 1984-07-13 | Steering hydrofoil |
GB08517517A Expired GB2161441B (en) | 1984-07-13 | 1985-07-11 | Hydrofoil steering mechanism |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB848417939A Pending GB8417939D0 (en) | 1984-07-13 | 1984-07-13 | Steering hydrofoil |
Country Status (1)
Country | Link |
---|---|
GB (2) | GB8417939D0 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2873346A1 (en) * | 2004-07-23 | 2006-01-27 | Philippe Bourbigot | Rudder blades or rudders` angle retaining device for boat, has connection bar connecting rudder blades together and having differential device to interlock blades at turning radius for adjusting angle of blades |
US20130299632A1 (en) * | 2011-01-25 | 2013-11-14 | Lisa Aeronautics | Motorized aeroplane with hybrid hydrodynamic and aerodynamic structure for taking off and landing on water, the ground or snow |
US20140202061A1 (en) * | 2011-07-22 | 2014-07-24 | Atli Mar Josafatsson | A trawl door or paravane with remote control adjustment |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1134011A (en) * | 1964-09-09 | 1968-11-20 | Peter Thomas Mence Nott | Improvements in hydroplanes |
GB1212380A (en) * | 1967-12-23 | 1970-11-18 | Hovermarine Ltd | Improvements in or relating to marine craft |
-
1984
- 1984-07-13 GB GB848417939A patent/GB8417939D0/en active Pending
-
1985
- 1985-07-11 GB GB08517517A patent/GB2161441B/en not_active Expired
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1134011A (en) * | 1964-09-09 | 1968-11-20 | Peter Thomas Mence Nott | Improvements in hydroplanes |
GB1212380A (en) * | 1967-12-23 | 1970-11-18 | Hovermarine Ltd | Improvements in or relating to marine craft |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2873346A1 (en) * | 2004-07-23 | 2006-01-27 | Philippe Bourbigot | Rudder blades or rudders` angle retaining device for boat, has connection bar connecting rudder blades together and having differential device to interlock blades at turning radius for adjusting angle of blades |
US20130299632A1 (en) * | 2011-01-25 | 2013-11-14 | Lisa Aeronautics | Motorized aeroplane with hybrid hydrodynamic and aerodynamic structure for taking off and landing on water, the ground or snow |
US9394047B2 (en) * | 2011-01-25 | 2016-07-19 | Lisa Aeronautics | Motorized aeroplane with hybrid hydrodynamic and aerodynamic structure for taking off and landing on water, the ground or snow |
US20140202061A1 (en) * | 2011-07-22 | 2014-07-24 | Atli Mar Josafatsson | A trawl door or paravane with remote control adjustment |
US9474256B2 (en) * | 2011-07-22 | 2016-10-25 | Atli Mar Josafatsson | Trawl door or paravane with remote control adjustment |
Also Published As
Publication number | Publication date |
---|---|
GB8417939D0 (en) | 1984-08-15 |
GB8517517D0 (en) | 1985-08-14 |
GB2161441B (en) | 1987-10-14 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
PCNP | Patent ceased through non-payment of renewal fee |