Abstract: A device for stabilizing yaw motion is provided for use on a helicopter having a main rotor rotatable about a main rotor axis, a power source, and a tail rotor boom with a longitudinal axis. The device includes a tail rotor and a gyroscopic mechanism. The tail rotor is mounted to the tail boom of a helicopter and is rotated about a tail rotor axis by the power source to generate a thrust force transverse to the tail boom and offset from the main rotor axis. The gyroscopic mechanism automatically varies the thrust force generated by the tail rotor to oppose yaw motions. The gyroscopic mechanism includes first and second variable pitch gyro arms extending along first and second gyro arm pitch axes, respectively, a support mechanism, and a pitch adjustor linkage.

Abstract: An engine cooling-system fan formed by combining two fan assemblies of like construction. Each fan assembly comprises a sheet-metal hub with radiating spokes, and a set of fan blades fastened one to each spoke. The hubs of both fan assemblies are riveted or otherwise joined together in axial alignment, with the two sets of fan blades arranged alternately at constant angular spacings. Preferably, the spokes of either or both of the fan assemblies are offset to provide the same plane of rotation for the two sets of the fan blades.

Abstract: A propeller blade having (i) a planar configuration (ii) an inner end portion, (iii) an outer end portion, (iv) a relatively sharp, outwardly swept back leading edge portion, and (v) a cylindrical stub axially aligned with the plane of the blade and affixed to the inner end portion of the blade. Also described is a mechanism that enables the pitch of the blades to be adjusted by the operator through a continuum of positions ranging from fast forward to fast reverse so that the boat can be operated at a full range and variety of speeds, can be stopped rapidly, and can be maneuvered with precision. The mechanism can be used for operating flat-bottom boats ("mud boats") in swamps, shallow water, bayous, lakes, rivers and the like, and pass through wet mud and swampy marshes choked with mud or vegetation without excessively fouling the propellers. The mechanism can be serviced and repaired easily and quickly, and can be employed to operate small craft such as mud boats with a minimum loss of interior boat space.

Abstract: Folding propeller which consists of blades (1) hinged to a hub (7) in such a way that they can turn about 56 degrees from a position at rest, where they are pointing aft, to a working position towards a stop. The identical movements of the blades (1) are achieved by the use of two cog-wheel connections, where each cog-wheel consists of only one tooth. The two connections are arranged side by side but in opposite directions in order to ensure a fixed connection. The tooth faces (10) may be given the shape of an arc of a circle. The propeller blades (1) may be fixed to the hub mechanism by means of pins (2) arranged in the longitudinal axis of the blades (1). The pitch of the blades (1) may then be changed.

Abstract: The device is composed of a conical section located on the edge of the disk rim. The greatest radius of the conical section is at least equal to the radius of the circumference passing through the bottom of the axial grooves into which the blade roots are inserted. A groove is formed in the end of the lower part of the root, this groove having a right angle triangular section. A locking part has one face pressed against the bearing and two other faces against the sides of the groove in the root. A blade extending longitudinally in the locking part works together with a groove in the slot of the blade root to keep the locking part in place.

Abstract: Gas turbine engine superalloy airfoils and other components having unique microstructures and novel combinations of physical properties are produced rapidly and economically by the method of the invention which uses the low pressure/high velocity plasma spray-casting process and segmented mandrels.

Abstract: A propeller formed from pliable sheet material with each blade being of looped configuration in plan view. An end segment of each blade is turned inwardly and attached to an inner segment of an adjacent blade at a point offset from the propeller hub portion. A blade root of each blade is of reduced width and extends between a blade inner segment and the propeller hub portion which is apertured to receive a motor output shaft having frictionally engaged disks thereon which oppositely abut the hub portion for shaft attachment purposes.

Abstract: A boat propeller with foldable blades, a so-called folding propeller, in which the mounting axes of the blades in the hub are inclined towards the rotational axis of the hub, so that the blades are movable between their folded and unfolded positions by rotating essentially one-half turn.

Abstract: A fan blade assembly having a spider shaped or formed from rod, wire or bar stock.

Abstract: Apparatus having radially disposed adjustable pitch fan blades embodies a split hub that is adapted to retain the blades in the plane of the hub. One portion of the hub includes an annular base with concentric upstanding inner and outer walls that define a channel. The outer wall includes a plurality of openings in which the blades are rotatably journalled with a cam portion of each blade extending into the channel. Cam follower means are slidably disposed in the channel and interlink adjacent cam portions so that rotation of any one blade will correspondingly adjust the pitch of each of the other blades. The blades are locked to a predetermined pitch setting by fastening the hub portions together. Another embodiment includes the fan blades and split hub which is bushed and secured to a shaft of a reversible drive motor.

Abstract: Feathering propeller particularly for auxiliary engines of sailing boats. The propeller comprises a device for transmitting a rotary and a positioning motion to the blades including planetary gear means for converting an angular motion of the drive shaft into an angular motion for inclining the propeller blades and means for halting the angular motion to halt the blades at the required inclination and render the blades of such inclination rigid both with the relative hub and with the drive shaft.

Abstract: An impeller of an axial-flow fan comprises a hub which carries blades installed thereon with the aid of attachment fittings in the form of a swivelling base with an extension. Each of the swivelling bases supports at least two blades. The distance between the blades installed on a single base varies from 0.15 to 0.3 .alpha. where .alpha. is the angular distance between the pivots of the adjacent swivelling bases. The blades installed on a single base are rigidly secured thereto at one end and joined to each other by a connector at the other end, thus forming a rigid system.

Abstract: A propeller fan comprising a pair of similar sheet metal spider-blade members each having a flat central hub section and two right angularly arranged pairs of narrow radially outwardly projecting spider arms. Each spider arm is twisted at an intermediate portion so that radially outer end portions of the arms of each pair are inclined in opposite directions relative to the hub section. A pair of air moving blades are formed integrally at inner end portions respectively with the outer end portions of the spider arms of one of the pairs of arms. A pair of laterally projecting blade support members are integrally formed respectively with the outer end portions of the other pair of spider arms. Each blade support member is approximately twice as wide as each spider arm and each blade is approximately four times as wide as each spider arm. The width and length of each blade are approximately equal.

Abstract: A multivane turbulator has been provided wherein at least two "V"-shaped members forming the vanes thereof are disposed with their vertices adjacent one another and twisted about each other such that the pitch of the twist is sufficient to render the turbulator self-supporting with symmetrically disposed vanes about a central axis.The method of forming the turbulators includes the steps of bending at least two strips of flat stock into "V"-shaped members and disposing one adjacent the other at their vertices and twisting same until the vanes are self-supporting.

Abstract: A rotary aerator is mounted for rotation about a horizontal axis and has a plurality of agitator elements formed integrally with hub segments to provide generally star-shaped members which extend radially from the circumference of the aerator along the length thereof for introducing air or other gases into waste water or other fluids.