Abstract: A motor-driven marine propeller is disclosed for propelling a marine vessel. The propeller includes a hub member driven by the motor and a can member disposed coaxially relative to the hub member the can member having a fore and an aft end. The hub member and the can member define therebetween an annular port for the passage therethrough of a portion of the exhaust generated by the motor. Supports extend between the hub member and the can member for supporting the can member coaxially relative to the hub member and a plurality of blades are secured to and extend from the can member with each of the blades being equidistantly spaced relative to each other. Each of the blades defines a leading and a trailing surface such that the propeller rotates in a direction from the trailing towards the leading surface in normal forward motion.

Abstract: An anti-theft device for a marine propeller has a spinnerplaced over the propeller nut which secures the propeller to the propeller shaft, and the spinner is held in place against unauthorized removal by a lock pin projecting from the propeller nut into an annular recess in the spinner, enabling the spinner to spin freely relative to the propeller nut while capturing the spinner against axial movement which would expose the propeller nut for unauthorized wrenching, the spinner including a radially extending access passage for gaining access to the lock pin with an authorized drive member to move the lock pin out of the annular recess for selective release of the spinner from the propeller nut and authorized access to the propeller nut for wrenching.

Abstract: A multi-bladed propeller and shaft assembly is provided in which air can be fed to the propeller blades to reduce the effects of cavitation. A shaft leads to a multi-bladed propeller and carries a sleeve formed with inlet passages and axial and radial passages leading to the respective blades. A slip ring supported in an anti-rotation device allows the shaft sleeve to rotate within axially spaced bearings of the slip ring. Axially spaced air seals together define with the body of the slip ring an annulus within which inlet passages rotate. Each seal is formed as a multiplicity of arcuate segments resiliently biased towards the sleeve and having movably sealed end face portions to maintain pressure tightness. The body further has a radial flow passage for admission of air under pressure to the annular space and a flexible fluid connector connects the radial flow passage to an air supply line leading from the hull structure.

Abstract: An exhaust apparatus for a water jet propulsion boat having an engine exhaust passage provided inside an impeller shaft. The exhaust passage opens into the water jet at a position rearward of an impeller. Thus, the length of an engine exhaust pipe can be reduced, and it is possible to reduce the space required for installation of the exhaust apparatus. Since the engine exhaust gas is discharged into the water jet at a position to the rear of the impeller, no cavitation occurs at the impeller portion. Further, it is possible to utilize the engine exhaust gas as a gas layer constituting a pneumatic bearing for supporting the impeller shaft.

Abstract: Several embodiments of propeller constructions employing an improved fish line and weed cutting device that extends into a recess formed in the lower housing. In each embodiment, the cutting member is disposed radially inwardly of the recess to define a gap and one or more projections extend outwardly from the cutting member to fill the gap and define a narrow area that will prevent the entry of fish lines into the opening of the lower unit that defines the recess.

Abstract: Several embodiments of coupling arrangements for resiliently coupling a propeller to a driving shaft. In each embodiment, a first resilient means provides a resilient coupling for absorbing circumferential vibrations and a second resilient means for absorbing axial vibrations. In one embodiment of the invention, one of the resilient means comprises a coil spring. In the other embodiment, all of the resilient means comprise elastomeric sleeves. In a further embodiment of the invention, axial damping in both forward and reverse directions are provided.

Abstract: A marine propeller hub has an axial hole therein having a wavy, non-cylindrical surface consisting of a plurality of alternating peaks and valleys. A closely fitting resilient insert slips into the axial hub hole of the propeller hub and has an outer surface with peaks that extend into the respective valleys of the axial hub hole. The resilient insert has a cylindrical axial hole therein with a plurality of longitudinal keyways disposed in the surface of that hole. The keyways receive respective keys rigidly attached to the outer surface of a spline driver adaptor sleeve, the inner surface of which has keyways that receive the splines of a drive shaft of a marine motor. The resilient insert transfers torque from the driving shaft to the hub without slippage if the torque is less than a predetermined amount, and absorbs shock if the propeller strikes a rock or the like by allowing the peaks of the hub hole to compress the peaks of the resilient insert.

Abstract: The marine propulsion device lower unit includes a housing having a lower portion submerged in water and defining an internal passage communicating with the water. Corrosion protection for both internal and external parts of the lower unit is provided by a sacrificial, galvanic-type anode mounted on the submerged portion of the housing and including a first or outer portion having a surface exposed to water exterior to the lower unit and a second or inner portion having a surface exposed to water present in the passageway.

Abstract: A propeller and exhaust system for an outboard motor wherein performance is improved by permitting the flow of some exhaust gases in proximity to the propeller blades at low speeds so as to aerate this area and so as to preclude the aeration when the speed of the propeller exceeds a predetermined speed for improving thrust.

Abstract: A propeller assembly is usable in combination with a watercraft drive unit having a generally horizontal drive support tube fixed on the craft and a drive shaft projecting from the rear end of the support and rotatable about a drive axis. The drive assembly has a hub fixed on the shaft adjacent the support and having a front hub portion immediately behind the rear support end and a rear end spaced therefrom. A rear propeller is fixed to the rear portion of the hub so that it rotates therewith and with the shaft. A planet carrier defining a plurality of planet axes parallel to and spaced equiangularly about the drive axis is secured to the support so the planet axes are fixed relative to the support and drive axis. A sun gear fixed on the front portion of the hub within the planet axes meshes with respective planet gears rotatable on the carrier about the planet axes.

Abstract: A boating propeller for controlling the discharge of engine exhaust gases from the central hub of a boating motor unit by making provision for confining said gases to the inner most fraction of the structure (that within the shroud) and discharging it downstream of the propeller when operating the unit in either the forward or astern mode of operation.

Abstract: A marine propulsion device is provided including a lower unit having a gearcase and a propeller shaft housing located in the gearcase and supporting a propeller shaft for rotation. A propeller is mounted on the propeller shaft rearward portion for common rotation with the propeller shaft. A thrust bushing is carried by the propeller shaft and for transmitting forward thrust from the propeller to the propeller shaft. An annular sacrificial anode surrounds the propeller shaft and is positioned between the thrust bushing and the propeller shaft bearing housing for providing cathodic protection for the rearward end of the gearcase and the propeller shaft bearing housing.

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: Marine propulsion unit having a propeller assembly formed with exhaust gas passages through the propeller hub. An outer pipe is provided to encircle the propeller hub with a radial spacing and has a rear end extending beyond the rear end of the hub. The rear end of the exhaust gas is decreased in diameter at the rear end portion thereof so that the rear end opening of the outer pipe is smaller in diameter than the propeller hub so that the exhaust gas is forced to flow, during a reverse movement, from the exhaust gas passage in the hub to the space between the hub and the outer pipe. For facilitating manufacture of the outer pipe through conventional casting technique, the outer pipe is comprised of a front and rear parts which are mated together.

Abstract: A marine propeller includes a hub and a plurality of replaceable, respectively adjacently positioned blade support sections attached to the hub. The hub has a central portion and a plurality of spoke members that extend radially out from the central portion. Each of the blade support sections includes an inner lip that engages a respective one of the spoke members and an outer lip adjoining and overlapping the inner lip of an adjacent blade support section. Each pair of adjoining outer and inner lips are drawn tightly against a respective one of the spoke members by a plurality of screws. The spaces between the respective spoke members form a plurality of exhaust gas passages.

Abstract: A propeller for controlling the discharge of gases and cooling water exhausting from the central hub of an outboard motor unit comprising a cylindrical shroud surrounding the propeller hub to confine the exhaust to the inner most part of the blades and discharge it downstream of the propeller when operating the unit in the forward or reverse mode. Several attachments to this shroud which enhance the discharge performance of the propeller are disclosed. An alternate embodiment comprises a shroud which may be attached to a conventional through-hub marine propulsion device to channel the exhaust away from the propeller area.

Abstract: A propeller (18) having an exhaust discharge passage (22) through the propeller hub has blades (24) symmetrical in thickness about the nose-tail pitch line and symmetrical in plan form about a rake line (26). The propeller (18) is particularly effective to increase reverse thrust when used with an outboard drive unit (10) having exhaust gas relief passages (27).

Abstract: Disclosed herein is a foldable propeller assembly adapted for connection to a drive shaft. The propeller assembly includes a propeller carrier having an open end portion defining an axially extending mounting socket for receiving the drive shaft and a hub end portion spaced from the open end portion. A pair of propeller blades are pivotally mounted on the hub end portion for movement from a folded-together, collapsed position to a radially outwardly extending operative position in response to rotation of the propeller carrier and for movement from the operative position to the collapsed position in response to cessation of rotation of the propeller carrier.

Abstract: The invention relates to an accessory for outboard motors, Z-drives for boats or the like, the exhaust gas of which is normally conducted through the propeller hub into the water. By means of a valve system, which is suitably automatically changed over by the direction of rotation of the propeller, the exhaust gas, during rearward rotation of the propeller, is conducted to a region which lies outside the propeller suction, while the exhaust gas, during forward rotation of the propeller, flows out in the usual manner through the propeller hub. The success of the invention lies in a significant increase of the propeller propulsion during rearward travel.

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: Marine propulsion unit having a propeller assembly formed with exhaust gas passages through the propeller hub. An outer pipe is provided to encircle the propeller hub with a radial spacing and has a rear end extending beyond the rear end of the hub so that the exhaust gas is forced to flow, during a reverse movement, from the exhaust gas passage in the hub to the space between the hub and the outer pipe.

Abstract: Disclosed herein is a marine propulsion device comprising a lower unit including a gear case having a hollow interior and having at the rearward end thereof an inwardly extending inner circular surface defining an opening through which exhaust gases and engine cooling water are discharged from the lower unit, and a propeller shaft rotatably journaled in the gear case and including a portion extending rearwardly of the gear case. A propeller including a hub is mounted on the propeller shaft rearward portion for common rotation of the hub with the propeller shaft. The propeller also includes a forward portion adjacent the rearward end of the gear case, and a propeller blade extending radially outwardly from the hub.

Abstract: An improvement to a marine propeller in which engine exhaust gases are discharged through the hub consists of an extension formed with inwardly projecting helical fins. The extension is adapted for mounting on the propeller distal of the shaft end of the hub.

Abstract: Disclosed herein is a marine propulsion device comprising a lower unit including a gear case including a hollow interior having at the rearward end thereof an inwardly extending inner circular surface defining an opening through which exhaust gases and engine cooling water are discharged from the lower unit, a propeller shaft rotatably journalled in the gear case and including a portion extending rearwardly of the gear case, a propeller including an inner part mounted on the propeller shaft rearward portion for common rotation of the inner part with the propeller shaft, an outer part having an outer circular surface with a diameter materially less than the diameter of the inner circular surface of the gear case, a blade extending radially outwardly from the outer part, and a resilient cushion connecting the inner and outer parts, and a thrust washer carried by the propeller shaft in forward thrust transmitting engagement therewith and in forward thrust receiving engagement with the propeller outer part, and a

Abstract: Disclosed herein is a marine propulsion device comprising a lower unit including a gear case including a hollow interior having at the rearward end thereof an inwardly extending inner circular surface defining an opening through which exhaust gases and engine cooling water are discharged from the lower unit, a propeller shaft rotatably journalled in the gear case and including a portion extending rearwardly of the gear case, a propeller including an inner part mounted on the propeller shaft rearward portion for common rotation of the inner part with the propeller shaft, an outer part having an outer circular surface with a diameter materially less than the diameter of the inner circular surface of the gear case, a blade extending radially outwardly from the outer part, and a resilient cushion connecting the inner and outer parts, and a thrust washer carried by the propeller shaft in forward thrust transmitting engagement therewith and in forward thrust receiving engagement with the propeller outer part, and a

Abstract: A reversible outboard motor is provided with structure for distribution of the exhaust gas from the motor away from the propeller and which may be integral or an attachment for existing outboard motors.

Abstract: An outboard marine propulsion apparatus has a rotor unit axially displaceable between forward and reverse operating positions. In the forward position, concentric horizontal paths through the apparatus are provided for rearward discharge of the propulsive water stream and the engine exhaust gases; in the reverse position, paths are provided for discharging the propulsive water stream forwardly and the exhaust gases in radially outward directions ahead of the rotor unit. For reverse operation one of the concentric flow paths is closed by an automatically actuated butterfly valve responsive to the axial displacement of the rotor unit. A dashpot device controls the axial sliding speed of the rotor unit.

Abstract: This invention relates to hollow hub marine propellers provided with an external groove girdling the hub disposed between the propeller blades and the rear hub opening. The walls of the groove or annular cavity do not extend outwardly of the hub and thereby offer minimal water resistance. The groove serves to minimize forward migration of exhaust gas issuing from the rear end of the hub, thus to minimize blade cavitation.