Abstract: The invention relates to an arrangement in propeller installations including means for supplying motor exhaust gases to the vicinity of the propeller (7). The invention is characterized in that a gas outlet (4) is located immediately forwards of the propeller and directs the gas flow towards the sweep of the blade tips of the propeller.

Abstract: A system for supporting an outboard propulsion unit to the transom of a boat. The system is comprised of a pair of transom brackets which are fixedly secured to the boat transom and positioned spaced from each other to support the outboard propulsion unit. A pair of deflector side plate sections are provided to be respectively integral with the transom brackets, and extend downwardly and rearwardly relative to the boat transom. Additionally, a deflector bottom plate section is provided to connect the lower end portions of the deflector side plate sections. The deflector bottom plate section extends rearwardly relative to the boat transom and positioned between the boat and the outboard propulsion unit. The deflector side and bottom plate sections constitute a deflector for regulating backward water flow from the boat transom, thereby preventing generation of water splash.

Abstract: A water deflector or splash guard for diverting water away from the powerhead and bracket assemblies of an outboard motor during operation of a boat. The splash guard includes a flat planar head portion extending forwardly of the gearcase and a body portion extending rearwardly of the head portion comprising a pair of spaced apart fin members disposed on opposite sides of the gearcase. In one form, the splash guard is substantially U-shaped and is mounted between the anti-ventilation plate and spray plate of an outboard motor exteriorly of the outer surface of the gearcase. In another form, the splash guard includes an integral tail section and is mounted by being sandwiched between the gearcase and drive shaft housing.

Abstract: A propeller enclosed in an open tube and attached to the tube, with the tube being driven by an engine through a ring gear rack on the outside of the tube, a stationary housing concentrically outside the tube and attached to the boat hull, bearings and seals between the housing and the tube to permit the space between the housing and tube to be filled with lubricating oil, and a pivotable rudder located partially inside and partially outisde the aft end of the tube.

Abstract: A ship's propeller is mounted so its blades will rotate closer to the shell plating of the adjacent hull, than is generally considered advantageous. A recess is formed inside the shell plating in the region of the propeller, the recess having a depth locating its inward wall at a distance from the tips of the rotating propeller blades corresponding to about 25% of the propeller diameter. The recess can be provided with a number of spaced-apart, transverse bars having a height less than the maximum depth of the recess.

Abstract: A marine outboard drive having a lower housing configured to generate the necessary side forces to balance the side thrust of the propeller regardless of the degree of submersion of the propeller in the water.

Abstract: A marine drive apparatus including a shroud channel selectively rotatable to direct the water produced by a rotatable propeller so as to provide reversing and steering of a marine craft. The shroud channel has spaced side walls joined by a roof portion, the side walls being used to deflect the water flow so as to produce a steering thrust and the roof portion being movable aft of the propeller to deflect the water flow and produce a reverse thrust.

Abstract: Vanes are mounted to an assembly affixed upstream of propeller blades of an utboard motor, creating a counterswirl in the fluid flow to counter the swirl produced by the propeller rotation, enabling on essentially axial discharge jet. The vanes are applied to only a 180 degree sector of the inflow to the propeller.

Abstract: Improved cooling is provided for a marine twin drive to prevent overheating, particularly during turns. It has been found that a low pressure path (46) exists along the strakes (24, 26) on the bottom surface (20) of the boat hull (12). Air can enter at the water surface (48) and be channeled longitudinally rearwardly along the bottom of the boat hull along the strakes and be ingested in the propulsion units (16, 18) which are generally longitudinally aligned with and rearward of the strakes. The low pressure path is eliminated by modified strake structure (26a) occupying the space (44) otherwise causing such low pressure path.

Abstract: A marine drive (2) is provided with an anti-ventilation plate (22) having a forward horizontal portion (24) and an aft portion (26) extending downwardly at an angle (28) to horizontal and noncoplanar with the forward portion (24). An adjustable anti-ventilation plate (30, 58) is also provided. The preferred form of the adjustable anti-ventilation plate is particularly simple and readily added to existing structure.

Abstract: A water deflector or splash guard for diverting water away from the powerhead and bracket assemblies of an outboard motor during operation of a boat. The splash guard is mounted on the bottom of a transom bracket assembly, and includes a flat planar body having a pair of rearwardly extending spaced fins that define a central opening for receiving the lower unit of the outboard motor. The splash guard also includes a pair of downwardly angled tab members extending rearwardly from the body and disposed between the fin members to aid in deflecting water and provide a central recess for accommodating the drive shaft housing and swivel bracket of the outboard motor as well as a notch for accommodating the grounding wire of the motor.

Abstract: A thrust collar is disclosed for mounting around the upper portion of the propeller of an inboard/outboard engine. Each thrust collar supports a horizontal hydrofoil wing extending laterally from the collar. A second, similar wing can be provided on an opposing side of the collar. Where the collar is used in pairs on paired engines on a catamaran hull, a single hydrofoil wing can be supported between the thrust collars. The thrust collar is preferably used in conjunction with hull lifting structures. One hull mounted hydrofoil structure is supported at the lower end of the strut extending and includes a generally curvilinear gull-wing shaped lower surface. For V-type hulls, a pair of elongataed mechanical lifting structures, symmetrically positioned on either side of the keel substantially in the vicinity of the keel are attached to the hull so as to extend generally traversedly to the sloping side surfaces of the hull intersecting at the keel.

Abstract: A combined propulsion and steering system for motor boats with inboard engines comprises a propeller shaft projecting from the lower part of the transom of the boat and carrying a semi-submerged propeller screw which is enclosed by an arch-like deflector tunnel extending over and to the sides of the said propeller screw and turnable about a substantially vertical axis. The ratio (L/D) between the distance (L) from the rear part of the propeller screw to the lower rear part of the transom hull and the outer diameter (D) of the propeller screw lies between 0.8 and 1.8. There is also provided an engine exhaust gas duct, forwardly of said propeller screw.

Abstract: A horizontally elongated panel constructed of dielectric material is provided including front and rear ends. The panel is provided with a longitudinal slot closed at its forward end and open at its rear end and the front end of the panel is forwardly and upwardly curved. The lower unit of an outboard motor is forwardly, snugly seatable within the slot and the panel is mountable from the opposite side outwardly projecting cavitation plate portions of the lower unit. The panel functions as a water confining panel for disposition substantially at the surface of an associated body of water for sealing the area in which the outboard motor propeller turns against the entrance of ambient air into the water from above the water surface.

Abstract: An improved outrigger type supporting arrangement for an outboard drive that further includes a baffle plate for redirecting water downwardly and away from the supporting arrangement when traveling at low speeds. The baffle plate is configured so as to direct the water flow downwardly and under the splash plate of the outboard drive during slow speed running conditions.

Abstract: An outboard motor drive shaft housing attachment apparatus includes at least one extended fin plate, having a raised front portion and a pair of angled side portion and an attachment bar shaped to fit an opening in the outboard motor shaft housing. The attachment bar is passed through the opening in the shaft housing and removably attached to the fin plate with fasteners. Additional fasteners are used to attach the fin plate to the outboard motor shaft housing. The fin plate can have anti-skid steps formed thereon and a sacrificial anode attached thereto. A method of attaching an outboard motor attachment, comprises the steps of removing the outboard drive shaft housing sacrificial anode to leave an opening through the housing; sliding a shaft through the opening in the housing created by the removal of the sacrificial anode; attaching a fin plate to the shaft extending through the shaft housing opening; and then attaching the fin plate directly to the housing with threaded fasteners.

Abstract: An outboard engine bracing system for utilization on a boat hull having a transom. The outboard engine bracing system comprises an outboard extension formed integral with the boat hull and being located above the actual transom of the hull and extending rearwardly beyond the transom. A plurality of brackets are interposed between the transom and the outboard extension, being formed integral with the transom and the outboard extension. The outboard engine bracing system is adapted to have mounted thereon a conventional outboard motor.

Abstract: A boat stabilizer is disclosed for substantially eliminating "porpoising" or up and down movement of the bow portion of a boat as the boat is moving through the water. The stabilizer includes a wedge-shaped member formed on an adjustably mounted trim tab located on the underside of an anti-cavitation plate of an outboard motor. The wedge-shaped member has a downwardly inclined lower surface extending generally laterally from and perpendicularly to a fin-shaped member of the trim tab. Movement of the boat through the water imparts a force against the downwardly inclined surface to effect a generally vertical torque on the boat substantially eliminating porpoising of the boat in a given speed range. The force imparted against the downwardly inclined surface is proportional to the angle of attack of the downwardly inclined surface so that upward displacement of the bow of the boat moving through the water is opposed by a proportionately greater force on the downwardly inclined surface.

Abstract: A shell made up of opposed halves is fitted over the propeller screw of the motor on the boat. This shell then becomes an enclosure with inlet and outlet openings at the ends. This shell with the propeller screw forms a pump with the propeller screw pumping water through the shell and through an outlet hose which is extended to the shore. One form has the inlet and outlet openings on the axis of the propeller screw and other forms include the outlet arranged tangentially or angularly. A hose can be connected to the inlet opening for bailing a boat.

Abstract: A marine craft having a propeller tunnel in which the sidewalls of the tunnel are essentially parallel and vertical and mate with a descending upper surface of the tunnel which optionally can be divided into a transom plate portion, engine plate portion, and bottom plate portion. The bottom plate portion mates with the bottom of the boat hull in a sharp line intersection. A surfacing propeller and associated drive shaft is mounted in the tunnel with a rudder positioned aft of the surfacing propeller. Baffles are provided on the lateral sides of the tunnel and terminate in a forward portion aft of the bottom plate portion of the tunnel. Optionally the exhaust can be vented onto the bottom plate portion of the tunnel to augment the flow of air.

Abstract: A propeller guard includes a rigid U-shaped sleeve which has a pair of legs extending on either side of the lower housing in the motor. The cavitation plates on the lower housing are received within a U-shaped channel formed in the sleeve for mounting the guard upon the motor. A cylindrical shield having an open inlet end and an open outlet end is secured to the sleeve and encircles the propeller to protect the propeller from contact with foreign objects. A frame member extends downwardly from the forward edge of the sleeve to the lower portion of the inlet end of the shield and engages the leading edge of the lower housing to provide structural support for the guard. A plurality of horizontally disposed ribs extend from the frame member to the shield to further protect the propeller from contact with foreign objects. A gridwork is pivotally mounted over the open outlet end of the shield to further protect the propeller from contact with foreign objects.

Abstract: A thrust augmenter for a propeller fluid drive (11) comprising a hollow substantially cylindrical body (12) having an open rear face (15) which is part circular or circular and is located closely adjacent and ahead of the propeller (11) wherein the outside diameter of the rear face (15) is larger than the propeller (11).

Abstract: A transom bracket adapted to be mounted on a boat transom and adapted to extend rearwardly of the boat transom to support a propulsion unit rearwardly of the boat transom. The transom bracket includes a water deflection device for preventing water from impinging against portions of the propulsion unit lower unit when the lower unit moves through the water. The water deflection device includes first and second deflection surfaces, sloping downwardly and converging, the first and second deflection surfaces including spaced apart upper surface portions, and lower surface portions which converge and define a line extending between the transom and the lower unit.

Abstract: A ship has a stern provided with a propeller that rotates in a plane about a horizontal midline ship axis perpendicular to this plane to displace the ship horizontally forward and a plurality of fins secured to and extending horizontally from the stern ahead of the propeller in the ship displacement direction. Each such fin is curved and has relative to this direction a leading edge directed parallel and into the direction of boundary-layer flow at this leading edge and a trailing edge extending parallel to the axis. The leading edges of this invention are normally directed upward and the fins project horizontally from the stern by a distance at most equal to the thickness of the boundary-flow layer, also measured horizontally and perpendicular to the stern at the respective fin. The fins are arranged in vertical rows on each side of the stern ahead of the propeller.

Abstract: A deep vee entry hull is disclosed and includes a central running surface flanked in the after portion thereof, by inboard, intermediate and outboard running surfaces. The central and inboard surfaces terminate at the aft ends thereof in a first transverse step while the intermediate running surfaces terminate in a second transverse step aft of the first.

Abstract: A self-propelled spherical vehicle (10) for operation in a fluid medium utilizes an impeller (12) of approximately half the diameter of the sphere for propulsion. In addition to driving the vehicle, the impeller acts to draw the flow of fluid smoothly over the after part of the sphere, thus avoiding or minimizing the tendency of the fluid flow to separate from the surface and create turbulence. Compensation for impeller torque is effected in one embodiment by a series of non-rotating stator blades (14) carried coaxially of and immediately aft of the impeller and which are curved to counter the torque of the impeller on the vehicle. The stator structure is supported at the rear of the housing by brackets (18) including pivotal supports providing support in the vertical plane.

Abstract: A safety shroud for attachment to the rear surface of the transom of an unmodified boat hull equipped with an inboard engine and a propeller tube and shaft rigidly fixed to the engine and extending with clearance through an enlarged opening in the transom, and a propeller on the shaft; the shroud being longitudinally and transversely downward concave to overlie the top and partly enclose the sides of the propeller, the shroud in longitudinal section being upwardly and rearwardly curved from the forward bottom edge of the shroud to just ahead of the propeller zone and then extending straight rearwardly. The lateral edges of the shroud extend generally upwardly and rearwardly from the forward bottom edge of the shroud to merge with the top rear edge thereof. Preferably the shroud is composed of inner and outer interconnected plastic shells, the outer shell having a downward concave reinforcing strut, closed at its bottom by the inner shell, and having a metal rudder support shaft therein.

Abstract: A seagoing vessel comprises a hull having a forwardly projecting bulb at its bow. The bulb includes an upper periphery oriented substantially horizontally and exposed above the water surface when the vessel is stationary and in a fully loaded condition. A pair of side skegs extend rearwardly from an underside of the vessel at the stern end. Propeller shafts extend through the side skegs. The side skegs and propeller shafts converge in a rearward direction. Each side skeg includes a planar outboard surface and a bulbous inboard surface, the latter inducing an outboard flow of water through a top segment of the associated propeller in a direction opposite the direction of propeller rotation. A center skeg extends between the side skeg and includes downwardly converging and rearwardly diverging sides which induce an outboard flow of water through a top segment of a respective propeller in a direction opposite the direction of propeller rotation.

Abstract: An asymmetric aftbody for the hull of a ship having a twisted shape operative to achieve higher efficiency at practically all aftbody block coefficients by improving water flow and adapted to provide a shape wherein the tangential components of the wake are distributed as favorably as possible over the entire propeller circumference, the aftbody having an upper part above the propeller shaft which is combined with a part of the hull below the propeller shaft, the sectional areas of the hull having a bulbous or a U-shaped configuration with the center lines of the sectional areas being inclined away from the vertical longitudinal plane through the propeller center in opposite directions to that of propeller rotation such that when seen from aft the bulbous or U-shaped stern below the propeller shaft forms an angle of inclination with the vertical longitudinal plane in a direction opposite to that of propeller rotation.

Abstract: A double propeller drive unit for boats having an inclined steering axis and a trim fin arrangement which is fixed to the cavitation plate of the drive unit, is disposed in the boundary region between the propellers, and is designed to balance torques acting on the drive unit.

Abstract: A stabilizer for boats, the stabilizer being of generally delta planform, having a positive upper camber and a negative lower camber in chordwise cross section, being mountable upon a propeller post and in adjacent spaced relation from the propeller and adapted to be submerged, the stabilizer providing a lifting force to the stern, a downward force to the bow and a generally stabilizing affect upon the boat to which it is adapted.

Abstract: This disclosure relates to a side thruster for a ship. The thruster includes a propeller mounted in a cylindrical tunnel formed on the ship, and a housing-support is connected between the propeller and the hull of the ship for supporting the propeller in the tunnel. The housing-support extends substantially transversely of the direction of water flow through the tunnel, and it is generally elliptical in cross section. At least one enlargement is formed on the outer surface of the housing-support for reducing the effect of K/a/ rm/a/ n vortexes, and the enlargement preferably spirals around the outer surface of the housing-support.

Abstract: The marine propulsion device includes a lower unit having a gear case normally submerged in water and arranged to discharge engine exhaust gas rearwardly from the rear end into the water exteriorly of the propeller hub. A ring member or thrust ring including a hub mounted on the propeller shaft for common therewith, an annular collar and a plurality of circumferentially-spaced, radially extending spokes or ribs interconnecting the annular collar and the hub serves as a fishline and weed cutter. The annular collar includes an annular outer surface which extends closely adjacent an annular inner surface in the interior of the gear case adjacent the trailing edge of the gear case.

Abstract: An hydrofoil assembly for small craft is disclosed. The assembly includes two hydrofoils independently mounted on a boat or a propulsion unit of the boat's motor for free pivotal movement between a depending position and a extended in-use position. The foils automatically adopt the in-use position during forward movement and drop to their depending positions whenever their angle of attack becomes negative, such as in reverse movement when pivoted up to clear an obstacle, or when the boat is stationary.

Abstract: A unitary assembly (10) for mounting a surface propeller (52) on the transom (T) of a boat hull (H). The assembly comprises a plate (12) for attachment to the hull (H); a prop shaft support (16) fixed to the plate (12) for juxtaposition against the transom (T); and, a rudder support arm (20) fixed to the plate (12) and extending rearwardly therefrom above and in spaced relationship to the shaft support (16). As a result of its unitary construction, the assembly provides for ready attachment of a surface prop to a hull without major hull modification or the necessity of aligning separate shaft bearing supports and rudder elements. In its preferred embodiment, the assembly also includes a propeller hood supported by the arm and a spray deflector at the aft end of the hood.

Abstract: A high performance speedboat with a planing type hull and incorporating a drive mechanism having a one or two-speed-forward, step-up, V-gear, hydraulic transmission, which connects the engine drive shaft and the propeller shaft in V-drive structure. The propeller shaft extends rearwardly through the boat transom to provide a "thru-drive" system in coaction with a unitary strut and stern steering support assembly for placement on the boat transom. Such assembly includes a planar transom member secured to the boat transom, and a rearwardly extending, generally horizontal, planar structural member secured to the transom member and extending rearwardly of the boat. The structural member is bifurcated and has a pair of spaced rear end portions having rudder support means operatively disposed thereon for receiving rudder assemblies therein. Also provided is a pair of spaced strut support members secured to the assembly and extending downwardly therefrom with each having a propeller shaft support.

Abstract: Disclosed herein is an outboard motor comprising a propulsion unit including a rotatably mounted propeller, structure adapted to be fixedly connected to a boat transom and connected to the propulsion unit for mounting of the propulsion unit for pivotal movement about an axis which is horizontal when the mounting structure is boat mounted, a trim tab mounted on the propulsion unit for pivotal movement about an axis transverse to the horizontal axis, and a linkage for displacing the trim tab about the transverse axis in response to movement of the propulsion unit about the horizontal axis.

Abstract: Disclosed herein is a marine propulsion device including a downwardly extending propulsion leg, the lower end of the propulsion leg including a gear case, a drive shaft housed in the propulsion leg, a propeller shaft located in the gear case, and a propeller mounted on the propeller shaft, rotary operation of the marine propulsion device producing a steering torque on the propulsion leg. The propulsion leg also includes a skeg extending downwardly from the gear case, the rearward edge of the skeg comprising a foil for producing a torque on the propulsion leg opposite to the torque produced by rotary operation of the marine propulsion device.

Abstract: An engine driven outboard drive unit for propelling a watercraft has a vertical drive shaft driving a horizontal propeller shaft on which a propeller is mounted. The drive unit has a gearcase torpedo which houses both the propeller shaft and an annular exhaust gas passage. The exhaust passage discharges aft through the plane of the propeller. A small annular projection is formed around the aft end of the torpedo to improve high speed performance.

Abstract: A tubular duct is provided for ship propellers with blade tips having barrier plates extending transversely therefrom. The tubular ducts are effectively arranged to extend the barrier plates in a manner which, in operation, directs a fluid stream in substantially shock-free contact with such plates.

Abstract: A trimming wedge is disclosed to trim a propeller driven boat for better performance. The wedge is fixed at its base to the center shaft housing of a propeller driven power boat. The trimming wedge extends approximately the length of one blade of the propeller and is positioned in front of and in line with the propeller blade. The trimming wedge or vane splits the water in front of the propeller so that the blade of the propeller passes through a void in the water. For example, when the wedge is positioned vertically downwardly from the shaft housing, the void occurs when the clockwise arc of the blade is in about the downward four o'clock to eight o'clock position when viewed from the rear. A trimming wedge with the proper wedge angle neutralizes the tendency of the propeller to "walk" the boat sideways or to the right with a clockwise turning propeller, thus transferring the side load thrust to forward thrust when the boat is propelled through the water, resulting in an increase in forward speed.