Methods and arrangements for redirecting thrust from a propeller

Abstract

Methods and arrangements to redirect a forward thrust generated by a propeller of a watercraft to provide a non-forward thrust are disclosed. More specifically, embodiments comprise a control surface to redirect the forward thrust from the propeller. Based upon a position (i.e., distance and orientation) of the control surface with respect to the propeller, the redirection generates the non-forward thrust or thrusts. By redirecting a component of the forward thrust back toward the bow, the net forward or reverse, port or starboard thrusts and rotational thrust can be adjusted in fine increments. For instance, by adjusting the amount of prop wash hitting the control surface, the magnitude of the redirected thrust from the control surface can be adjusted. Further, adjusting the angle of the control surfaces adjusts the direction as well as magnitude of a reverse thrust component. The net thrust can be in any direction and rotational.

What is claimed is: 
     
         1 . An apparatus to redirect a thrust generated by a propeller for a watercraft, comprising:
 a control surface to redirect the thrust from the propeller based upon a position of the control surface with respect to the propeller, wherein the redirected thrust comprises a component of non-forward thrust; and   a first member is to couple with the watercraft to apply force to adjust a spatial relationship between the control surface and the propeller to position the control surface at least partially within an area in which prop wash is to be expelled by the propeller.   
     
     
         2 . The apparatus of  claim 1 , further comprising an adjustable member to couple with the control surface to adjust an angle of the control surface with respect to the thrust. 
     
     
         3 . The apparatus of  claim 2 , wherein the adjustable member is adapted to apply a vertical force to lower the control surface from a position substantially parallel with a water line to a position substantially perpendicular with the thrust to be generated by the propeller. 
     
     
         4 . The apparatus of  claim 2 , wherein the adjustable member is adapted to apply an angular force to the control surface to adjust an angle of the control surface, which adjusts the angle of impact of the thrust on the control surface. 
     
     
         5 . The apparatus of  claim 2 , wherein the adjustable member comprises a power-assisted, adjustable arm. 
     
     
         6 . The apparatus of  claim 1 , wherein the control surface is integral to a hull of the watercraft. 
     
     
         7 . The apparatus of  claim 1 , further comprising a second member to couple with the watercraft, the second member to adjust an angle of the control surface with respect to the propeller in response to contact between the control surface and the second member. 
     
     
         8 . The apparatus of  claim 1 , wherein the control surface comprises a flat or curved plate with a bent edge. 
     
     
         9 . The apparatus of  claim 8 , wherein the bent edge of the control surface comprises a rounded shape. 
     
     
         10 . The apparatus of  claim 8 , wherein the bent edge of the control surface comprises an angular shape. 
     
     
         11 . The apparatus of  claim 8 , wherein the bent edge is a distinct member to be coupled with the control surface via a hinge. 
     
     
         12 . The apparatus of  claim 1 , wherein the control surface and the first member comprise at least part of a retrofit kit. 
     
     
         13 . The apparatus of  claim 1 , wherein the control surface comprises a rudder to couple with the first member to facilitate rotation of the rudder about an axis substantially perpendicular to the forward direction of the watercraft. 
     
     
         14 . The apparatus of  claim 1 , wherein the first member comprises a rigid member and the apparatus further comprises a non-rigid joint to couple the rigid member with the control surface to restrict movement of the control surface in at least one direction. 
     
     
         15 . The apparatus of  claim 14 , further comprising a spring coupled between the rigid member and the control surface, wherein the spring is adapted to apply the force to the control surface to maintain the control surface at least partially within the prop wash at least until a magnitude of the thrust reaches a threshold magnitude based upon a loading curve of the spring, which allows the control surface to disengage. 
     
     
         16 . The apparatus of  claim 15 , wherein the spring is adapted to apply the force to the control surface to provide a variable reverse thrust responsive to the thrust generated by the propeller. 
     
     
         17 . The apparatus of  claim 14 , wherein the non-rigid joint is adapted to rotate the control surface between a first position in which the control surface is substantially perpendicular to the thrust and a second position in which the control surface is substantially parallel to the thrust. 
     
     
         18 . The apparatus of  claim 1 , wherein the first member is to couple with the propeller to raise the propeller incrementally, directing at least part of the prop wash toward the control surface. 
     
     
         19 . The apparatus of  claim 1 , wherein the first member is to couple with the watercraft via an outboard motor. 
     
     
         20 . The apparatus of  claim 1 , the first member is to couple with a stern drive of the watercraft. 
     
     
         21 . The apparatus of  claim 1 , wherein the first member comprises an arm adapted to limit movement of the control surface in at least one direction. 
     
     
         22 . The apparatus of  claim 1 , wherein the first member couples with the control surface via a release mechanism to prevent damage when stresses on the apparatus related to redirecting thrust approach design limits. 
     
     
         23 . The apparatus of  claim 1 , wherein the first member couples with the control surface via a overload spring to prevent damage when stresses on the apparatus related to redirecting thrust approach design limits. 
     
     
         24 . The apparatus of  claim 1 , wherein the first member couples with an overload release valve to reduce hydraulic pressure in a hydraulic system when the hydraulic pressure approaches design limits of the hydraulic system. 
     
     
         25 . The apparatus of  claim 1 , wherein the first member is adapted to couple with a rudder of the watercraft to maintain alignment of an axis of rotation for the control surface with an axis of rotation for the propeller. 
     
     
         26 . A method to redirect a thrust generated by a propeller via a control surface for a watercraft, the method comprising:
 applying force via a first member to adjust a spatial relationship between the control surface and the propeller to position the control surface at least partially within an area in which prop wash is to be expelled by the propeller; and   redirecting the thrust from the propeller via the control surface based upon the spatial relationship of the control surface with respect to the propeller, wherein the redirected thrust comprises a component of non-forward thrust.   
     
     
         27 . The method of  claim 26 , further comprising adjusting the position of the propeller to direct at least part of the prop wash to the control surface. 
     
     
         28 . The method of  claim 26 , further comprising adjusting the position of the control surface to adjust a port/starboard tilt or a bow/stern trim. 
     
     
         29 . The method of  claim 28 , wherein adjusting the position comprises sensing a change in the tilt or the trim of the watercraft and responsively adjusting the position of the control surface. 
     
     
         30 . The method of  claim 26 , further comprising detecting a speed of the watercraft and adjusting the position of the control surface based upon the speed. 
     
     
         31 . The method of  claim 26 , further comprising detecting a change in direction of the watercraft and adjusting the position of the control surface based upon the change in direction. 
     
     
         32 . The method of  claim 31 , wherein adjusting the position of the control surface based upon the change in direction comprises adjusting a velocity of the watercraft to navigate the watercraft. 
     
     
         33 . The method of  claim 26 , further comprising determining the position of the control surface to direct the watercraft toward a set of coordinates. 
     
     
         34 . The method of  claim 26 , further comprising calculating an adjustment for the position of the control surface based upon input from an operator of the watercraft. 
     
     
         35 . The method of  claim 26 , further comprising modifying the propeller speed to adjust the magnitude of the thrust, wherein adjusting the magnitude of the thrust modifies a load on a spring, the load on the spring being determinative of the position of the control surface. 
     
     
         36 . The method of  claim 26 , further comprising disabling control by an operator of the watercraft to move the control surface into the prop wash while the watercraft exceeds a specified speed or the propeller exceeds a revolutions per minute threshold. 
     
     
         37 . The method of  claim 26 , further comprising adjusting the position of the control surface with respect to the propeller. 
     
     
         38 . The method of  claim 37 , wherein adjusting the position of the control surface with respect to the propeller comprises adjusting the position of the control surface to maintain a substantially constant speed. 
     
     
         39 . The method of  claim 37 , wherein adjusting the position of the control surface with respect to the propeller comprises adjusting a distance between the propeller and the control surface. 
     
     
         40 . The method of  claim 37 , wherein adjusting the position of the control surface with respect to the propeller comprises generating a net, non-forward thrust to move the watercraft in a non-forward direction. 
     
     
         41 . The method of  claim 37 , wherein adjusting the position of the control surface with respect to the propeller comprises adjusting an angle of the control surface with respect to the thrust to adjust the magnitude and direction of net thrust. 
     
     
         42 . The method of  claim 26 , wherein applying the force comprises incrementally raising the propeller to direct the prop wash to the control surface. 
     
     
         43 . The method of  claim 26 , wherein applying the force comprises applying pressure to an adjustable arm via a driver system to substantially maintain the control surface in the position. 
     
     
         44 . The method of  claim 26 , wherein applying the force comprises holding the control surface in the position via a rigid member coupled between the control surface and the watercraft. 
     
     
         45 . The method of  claim 26 , wherein applying the force comprises holding the control surface in the position via a spring coupled with the control surface. 
     
     
         46 . The method of  claim 26 , wherein redirecting the thrust comprises generating a net, zero thrust while the control surface is positioned at an angle substantially perpendicular to the prop wash, wherein the net, zero thrust is based upon the position, distance and angle between the control surface and the propeller. 
     
     
         47 . The method of  claim 26 , wherein redirecting the thrust comprises redirecting at least a portion of the thrust in a non-forward direction to steer the watercraft. 
     
     
         48 . The method of  claim 26 , wherein releasing the thrust further comprises releasing the control surface to prevent damage when stresses approach design limits. 
     
     
         49 . A watercraft capable of redirecting a thrust generated by a propeller, the watercraft comprising:
 a hull having a motor coupled with the propeller to rotate the propeller to expel prop wash to generate the thrust;   a control surface to redirect the thrust from the propeller, based upon a position of the control surface with respect to the propeller, wherein the redirected thrust comprises a component of non-forward thrust; and   a first member to couple with the hull to apply force to adjust a spatial relationship between the control surface and the propeller to position the control surface at least partially within the prop wash.   
     
     
         50 . The watercraft of  claim 49 , further comprising a rigid member coupled with the watercraft to contact the control surface when the control surface is at a selected angle of rotation with respect to a transom of the watercraft. 
     
     
         51 . The watercraft of  claim 49 , further comprising an adjustable member to couple with the control surface to apply the force. 
     
     
         52 . The watercraft of  claim 51 , wherein the adjustable member is coupled with a driver system to adjust a distance between the control surface and the propeller. 
     
     
         53 . The watercraft of  claim 49 , wherein the hull comprises a driver system coupled with the first member to adjust the position of the control surface with respect to the propeller. 
     
     
         54 . The watercraft of  claim 49 , wherein the control surface comprises part of the hull. 
     
     
         55 . The watercraft of  claim 49 , wherein the control surface comprises a first flat surface substantially perpendicular to the thrust and one or more other surfaces operating in conjunction with the first flat surface to redirect the thrust. 
     
     
         56 . The watercraft of  claim 49 , wherein the first member couples with the control surface via a spring. 
     
     
         57 . The watercraft of  claim 49 , wherein the first member couples with a shaft of the propeller to direct the prop wash at least partially to the control surface. 
     
     
         58 . A controller to redirect a thrust generated by a propeller via a control surface for a watercraft, comprising:
 a memory to store a current position of the control surface with respect to the propeller;   logic coupled with the memory to determine an adjustment for a spatial relationship between the control surface and the propeller based upon the current position; and   a driver interface to instruct a driver to adjust the spatial relationship between the control surface and the propeller to position the control surface at least partially within prop wash of the propeller to redirect the thrust, wherein redirection of the thrust by the control surface produces a component of non-forward thrust.   
     
     
         59 . The controller of  claim 58 , further comprising a calibration module coupled with one or more sensors to monitor a calibration of a position of the propeller based upon changes in propulsion responsive to the redirected thrust. 
     
     
         60 . The controller of  claim 58 , further comprising a sensor interface to couple with one or more sensors to provide data for the logic to determine the adjustment for the spatial relationship. 
     
     
         61 . The controller of  claim 60 , wherein the memory comprises non-volatile memory to store a formula to calculate the adjustment based upon input from the one or more sensors. 
     
     
         62 . The controller of  claim 58 , wherein the memory comprises data related to calculation of the adjustment. 
     
     
         63 . The controller of  claim 58 , wherein the driver interface is adapted to couple with a driver system to implement the adjustment. 
     
     
         64 . The controller of  claim 58 , wherein the logic comprises code and a processor to execute the code. 
     
     
         65 . The controller of  claim 58 , wherein the logic comprises at least one state machine. 
     
     
         66 . A control system for a watercraft to redirect a thrust generated by a propeller, comprising:
 a control surface to redirect the thrust from the propeller based upon a position of the control surface with respect to the propeller, wherein the redirected thrust comprises a component of non-forward thrust;   an attachment member coupled with the watercraft to apply force to modify the spatial relationship between the control surface and the propeller to position the control surface at least partially within an area in which prop wash is to be expelled by the propeller;   a driver to transmit the force from the watercraft to the attachment member; and   a controller to determine an adjustment for the spatial relationship between the control surface and the propeller and the communication with the driver to implement the adjustment.   
     
     
         67 . The control system of  claim 66 , further comprising a flexible member coupled with the control surface to adjust an angle of the control surface with respect to the thrust. 
     
     
         68 . The control system of  claim 66 , further comprising a second member coupled with the watercraft and adapted to adjust an angle of the control surface with respect to the thrust. 
     
     
         69 . The control system of  claim 68 , wherein the second member is adapted to move the propeller to adjust the angle of the control surface with respect to the thrust. 
     
     
         70 . The control system of  claim 66 , wherein the control surface comprises two rudders and the controller is adapted to rotate the rudders to substantially reflect the thrust back toward the propeller to generate the component of non-forward thrust. 
     
     
         71 . The control system of  claim 66 , wherein the control surface resides in a cavity formed into a hull of the watercraft and is adapted to reflect the thrust while a shaft of an inboard motor is raised to direct the prop wash at least partially into the cavity. 
     
     
         72 . A machine-accessible medium containing instructions to redirect a thrust generated by a propeller via a control surface for a watercraft, which when the instructions are executed by a machine, cause said machine to perform operations, comprising:
 applying force to position the control surface in water within an area in which prop wash is to be expelled by the propeller; and   redirecting the thrust via the control surface in response to generation of the thrust by the propeller, based upon a position of the control surface with respect to the propeller, wherein the redirected thrust comprises a component of non-forward thrust.   
     
     
         73 . The machine-accessible medium of  claim 72 , wherein the operations further comprise sensing a tilt of the watercraft and adjusting the position of the control surface based upon the tilt. 
     
     
         74 . The machine-accessible medium of  claim 72 , wherein the operations further comprise adjusting an angle of the control surface with respect to the propeller. 
     
     
         75 . The machine-accessible medium of  claim 72 , wherein the operations further comprise detecting a speed of the watercraft and adjusting the position of the propeller to adjust an impact of the prop wash on the control surface based upon the speed. 
     
     
         76 . The machine-accessible medium of  claim 72 , wherein the operations further comprise determining a direction for the watercraft to navigate the watercraft to a set of coordinates based upon input from a global positioning system. 
     
     
         77 . The machine-accessible medium of  claim 72 , wherein the operations further comprise modifying the propeller speed to adjust the magnitude of the thrust based upon a loading curve of a spring coupled between the control surface and the watercraft. 
     
     
         78 . The machine-accessible medium of  claim 72 , wherein applying the force comprises applying force to hold the propeller in a position in which at least part of the prop wash is directed toward the control surface. 
     
     
         79 . The machine-accessible medium of  claim 72 , wherein applying the force comprises applying force to move the propeller to a position in which at least part of the prop wash is directed toward the control surface. 
     
     
         80 . A database to redirect a thrust generated by a propeller via a control surface for a watercraft, comprising:
 thrust data to relate a current spatial relationship between the control surface and the propeller with a components of a current redirected thrust;   propulsion data to relate the components of the current redirected thrust with a current rotational and spatial velocity and acceleration of the watercraft; and   a formula to determine an adjustment to the positional and angular relationship based upon a difference between the current redirected thrust and a new propulsion, the adjustment to position the control surface at least partially within an area in which prop wash is to be expelled by the propeller to effect the new propulsion; wherein the adjustment is indicative of an application of force to implement the adjustment.   
     
     
         81 . The database of  claim 80 , further comprising correction factor data to be utilized via the formula to account for environmental conditions that affect a velocity of the watercraft. 
     
     
         82 . The database of  claim 80 , wherein the formula is adapted to determine adjustments for the current position of the control surface based upon input from a boat operator. 
     
     
         83 . The database of  claim 80 , wherein the formula is adapted to determine adjustments for the current position of the propeller based upon input from a boat operator.