Abstract:
A submarine is steered by means of a special bow assembly. The submarine has a body formed with a contoured surface and a forward portion forming a bow. The assembly comprises an annular member surrounding the bow with an outer surface complementary to the contoured surface of the body, and actuating means secured to the body for movement of the annular member forward and away from the bow at an angle to the longitudinal axis of the vehicle. When the annular member is displaced at the angle, the vehicle is caused to turn in the direction toward which the annular member is turned.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to an apparatus for steering a vehicle through a fluid medium, and more particularly, to an apparatus for increasing maneuverability of the vehicle when traveling at low speeds. 
     Vehicles traveling through a fluid medium typically have a steering system unique to the type of vehicle and the fluid medium. For example, a guided missile is initially propelled and steered by the thrust of rocket motors and the like. Similarly, a vehicle traveling through water, such as a submarine, is guided by fluid flowing over stern control surfaces. 
     However, at low speeds, the rate of fluid flow over the stern control surfaces is insufficient to generate sufficient thrust to maintain high rates of turn. This can be undesirable when the vehicle is traveling under certain operating scenarios where a higher rate of turn is required. 
     The present invention has the following objects: 
     an improved steering apparatus for increasing the mobility of a vehicle traveling through a fluid medium; 
     an improved steering apparatus to aid in the low speed maneuverability of a vehicle traveling through a fluid medium; and 
     an auxiliary improved steering apparatus providing a secondary method of steering a vehicle traveling through a fluid medium. 
     Other objects and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic plan view of the preferred embodiment of the present invention in the retracted position. 
     FIG. 2 is a schematic plan view of the embodiment of FIG. 1 in the fully extended position. 
     FIG. 3 is a schematic plan view of the embodiment shown in FIGS. 1 and 2 in a steering position. 
     FIG. 4 is an enlarged schematic view of the embodiment shown in FIGS. 1-3 taken as indicated in FIG. 3. 
     FIG. 5 is an enlarged schematic view of the embodiment shown in FIGS. 1-3 taken as indicated in FIG. 3. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the illustration of the present invention shown in FIGS. 1-5, there is illustrated a vehicle 10 propelled and steered in any conventional manner. Vehicle 10 has a body 12 with a contoured surface 14 and includes a bow 16 at the forward portion thereof. The vehicle may be, for example, a submarine or any underwater vehicle. 
     Surrounding bow 16 is an annular member 18. Annular member 18 is movable from a retracted position, as shown in FIG. 1, to a forwardly displaced position, shown in FIGS. 2 and 3, by means of an actuating means shown generally at 20. Bow 16 includes an annular concavity 24 extending circumferentially around bow 16 and adapted to receive annular member 18 therein when the annular member is retracted. Concavity 24 may be in any location along the bow, but is preferably in the forward region of the bow where contoured surface 14 is significantly curved. Concavity 24 is of a shape conforming to the inner surface of annular member 18 and need only be of a depth sufficient to accommodate the annular member 18 and the actuating means 20. 
     As best seen in FIG. 4, concavity 24 interrupts contoured surface 14, leaving a gap 25 in the contoured surface. Referring to FIG. 1, when annular member 18 is in the retracted position, an outer surface 22 of annular member 18 is designed to continue the surface contour of the vehicle, thereby filling gap 25. It is thus evident that when annular member 18 is retracted, there is no disruption in the fluid flow about the vehicle, which might otherwise slow the vehicle and generate flow noise. 
     Actuating means 20 is capable of displacing annular member 18 both linearly, as shown in FIG. 2, and angularly, as shown in FIG. 3. When annular member 18 is displaced linearly, the annular member is displaced forwardly out of annular concavity 24 parallel to a longitudinal axis A-A into the fluid flow about the vehicle. Referring to FIG. 3, actuating means 20 is capable of displacing annular member 18 in a direction forward and away from bow 16 at an angle 26 relative to longitudinal axis A-A of the vehicle. Angle 26 is variable as required to steer the vehicle in the intended direction. 
     As shown by hidden lines in FIGS. 4 and 5, annular member 18 preferably has a fluid foil cross-section 19. When annular member 18 is angularly displaced, as shown in FIGS. 3, 4 and 5, one side 30 of annular member 18 will be displaced forwardly, and an opposite side 32 will only be slightly displaced and will remain near annular concavity 24. Side 32 therefore acts as a spoiler. 
     As best shown in FIG. 5, a leading edge 34 of side 32 protrudes from bow contoured surface 14. As the vehicle moves forwardly in the fluid medium, leading edge 34 projects outwardly into the fluid flow, thereby disrupting the flow about vehicle 10. Fluid, which absent the projection of leading edge 34 into the fluid flow would travel uninterrupted about the vehicle, instead becomes caught between a trailing edge 36 of side 32 and the annular concavity. Consequently, this disruption in flow introduces drag to this side of the vehicle. The greater drag on this side means that the vehicle will tend to steer in this direction. 
     On the other side, the annular member 18 acts as a thruster. As seen in FIG. 4, when annular member 18 is angularly displaced, a leading edge 38 of forwardly displaced side 30 is spaced away from the contoured surface of the bow, as is a trailing edge 39. The fluid flowing between annular member 18 and the bow 16 is forced to exit predominantly on side 30. Because the fluid path under member 18 is narrowed by the fluid foil and because the fluid outlet at trailing edge 39 is smaller than the fluid inlet at leading edge 38, the velocity of the fluid exiting at trailing edge 39 is greater than the velocity of the fluid entering at leading edge 38, resulting in a thruster effect on side 30 of the vehicle. The drag produced on side 32 coupled with the thrust produced on opposite side 30 causes the vehicle to turn toward side 32, i.e., in the direction toward which the annular member is turned or angled. 
     The annular member may be displaced by any conventional actuating means. In a preferred embodiment, actuating means 20 includes a plurality of actuators 28 mounted inside the skin of the vehicle and pivotally attached at one end 29a to body 12 and at the other end 29b to the annular member 18. The actuators are preferably hydraulic, although any type may be used. To achieve the angular displacement described herein, each actuator 28 must be individually operable, thereby permitting the displacement of each actuator to be individually controlled by conventional hydraulic controls, not shown. It is also preferred that at least four actuators 28 be provided and that the actuators be equally spaced around the circumference of the vehicle bow. 
     The apparatus ma be used to steer the vehicle in any direction: up, down, to either side, or in a climbing or diving turn. 
     The pivoting action of actuators 28 is evident in comparing FIG. 2 with FIG. 3: in FIG. 2 the actuators are perpendicular to the plane of annular member 18 and to a plane perpendicular to the centerline of the vehicle, in FIG. 3, the actuators are at angles to both these planes. 
     Although annular member 18 will usually be used to steer the vehicle, as shown in FIG. 3, it may also be used in the position shown in FIG. 2 as a spoiler brake. This would help the vehicle slow down faster than it normally could. 
     The method of the present invention is performed by displacing the annular member forwardly. When the annular member is displaced at an angle to the longitudinal axis of the vehicle, a drag is produced by the spoiler at side 32 and a thrust is produced on the other or opposite side of the vehicle simultaneously. This combination of producing both a thrust and a drag on opposite sides of the vehicle creates a moment that forces the bow in the direction of the drag. 
     It can thus be seen that the present invention provides a relatively simple auxiliary steering assembly and method. When this steering assembly is coupled with conventional vehicular steering mechanisms, the maneuverability of the vehicle, particularly at low speeds, is greatly enhanced. 
     From the foregoing detailed description, it will be evident that there are a number of changes, adaptations and modifications of the present invention which could be made. However, it is intended that all such variations not departing from the spirit of the invention be considered as within the scope thereof, limited solely by the appended claims.