Abstract: This invention relates to a system for mounting a helicopter rotor on a flapping axis and, more particularly, to use of an improved unitary trunnion-bearing structure of minimal parts which may be selectively preloaded and which is readily installed.

Abstract: An improved air metering nozzle assembly for air bearings wherein the metering orifice is formed in a flat disc separate from air supply elements and is readily removable and replaceable.

Abstract: A fastening nut, which by virtue of precisely located laser cuts and the application of predetermined torque to a grip member, is enabled to break into several parts, one of which can be used as a jam nut. The nut is provided with an internally threaded sleeve, a grip member and interconnecting means, the latter of which may be provided with one or more shear areas by virtue of a series of laser cuts. At a predetermined torque on the grip member, the sleeve is sheared from the interconnecting means and grip member and, as a second embodiment, the interconnecting means may be provided with internal fastening threads so that further torquing of the grip member drives such interconnecting means into the sleeve and thereafter a second shear separation is effected to remove the grip member from the jam nut.

Abstract: A valve combining in a single unit a multiplicity of functions including isolation, thermal and pressure relief, return check and bypass. The valve includes a pair of spool valves, one slidably positioned within the other, disposed with a bore in a housing and interconnected with system pressure and return and an appropriate control valve.

Abstract: A high power, high frequency attenuator which provides attenuation steps ch are switchable at very high speed, the attenuator implementing a method by which the input signal is split into two separate signals which are then subjected to impedance mismatches in the signal path, so that a portion of the split signals are reflected back to the signal splitter for dissipation there and the remaining portions of the split signal are transmitted to a summing circuit for recombination and output. The value of mismatch imposed determines the degree of attenuation obtained. The splitting of the signal reduces the stress upon the mismatched components as well as permits high switching speeds of the mismatches in and out of the circuit. In one embodiment of the invention directional couplers are used to provide the signal splitting and recombination functions, with the result that high isolation is achieved between the input port and the reflected signal caused by the mismatches.

Abstract: A robot forearm has a pivotally mounted proximal end, a distal portion axially rotatable with respect to the remainder of the forearm, and a wrist connected to the distal portion and being angularly tiltable with respect thereto. A gear on the distal end of a first output shaft rotatably mounted in the remaining portion of the forearm drives a tilt gear assembly mounted in the distal portion of the forearm to tilt the wrist. A second output shaft concentric with the first shaft is connected to the distal portion of the forearm for imparting rotation thereto. Motors mounted in the forearm are coupled to the ouput shafts through concentric input shafts and harmonic speed reducing drives. The drives are axially spaced and concentric and are coupled to the output shafts by flexible cup-like members. Encoders connected to the second output shaft and the tilt gear assembly encode the position of those elements and produce corresponding feedback signals which are used to control the motors.

Abstract: A robot forearm is counterbalanced by a drive arm. A main arm has two parallel sections whose ends are pivotally connected to the forearm and drive arm to maintain a parallel relationship between the forearm and the drive arm. A medial portion of one main arm section is pivotably mounted on a turntable pedestal. A drive motor and drive system mounted on the drive arm are connected to the other main arm section for moving the drive arm relative to the main arm. The drive system includes a harmonic drive speed reducer.

Abstract: There is disclosed an improved air cushion supported vehicle of the relatively high speed operating "surface effect ship" type, having a main hull and a pair of rigidly constructed opposite side walls or hulls depending therefrom, and bow and stern air cushion sealing means. Each of the side hulls terminates at its lower extremity into an outwardly side-wise canted water planing bottom surface or keel into which one or more non-coplanar surface discontinuities is/are provided for locally accommodating in slightly recessed relation therein the ship propulsion propellers. The configurations of said discontinuities are such as to reduce the requisite angles of the propeller driving shafts relative to the ship hull; thereby reducing the ship draft (propeller clearance) requirements, while also providing under high speed operating conditions improved propeller operating efficiencies and substantial maintenance of the desired air cushion sealing efficiencies of the side hull keels of the ship.

Abstract: A mechanical drive assembly that is particularly useful for moving a sharpening stone into engagement with a sharpenable chain saw is mounted to the side plate of the chain saw housing. The stone moves linearly a predetermined stroke length toward and away from the chain, and the beginning position thereof is incrementally adjustable, to take into account wear of the stone. The stone may be returned to an original position, for replacement, in another distinct mode of operation.

Abstract: A helicopter tail rotor (14) is provided with a thrust ring. The thrust ring comprises an annular airfoil (16) having a circular opening which is aligned coaxially with the rotor (14). The plane of the airfoil (16) is essentially parallel to the plane of the rotor (14) but slightly offset downstream from the rotor (14). The cross section of the airfoil (16) can have a wide variety of configurations including flat and cambered. The tip vortices (30) produced by the rotor (14) are captured near the downstream surface of the airfoil (16) to produce a circulating airflow (32) that draws air from the upstream region of the airfoil (16) through the opening therein. The aerodynamic action of the airfoil (16) widens the wake diameter of the wash from rotor (14), increases rotor (14) thrust efficiency, reduces the noise level of rotor (14), enhances transverse stability and lowers the vibration level experienced by helicopter (10). The airfoil (16) further serves as a guard to protect the rotor (14).

Abstract: A first pattern, which has on its outer periphery a series of intersecting surfaces, is used in a conventional edger unit to control the rough grinding of a corresponding series of intersecting surfaces on the edge of a revolving lens blank. A second pattern is then inserted in the edger to control a first bevel grinding operation during which a bevel grinding wheel is caused intermittently to engage the revolving lens blank to form thereon a first plurality of angularly spaced, beveled surfaces at least one of which registers with one of the intersecting surfaces on the blank. A third pattern is then inserted in the edger to control a second bevel grinding operation during which the bevel grinding wheel forms a second plurality of beveled surfaces on the lens blank in the spaces between the first plurality, and in registry with the remainder of said flat surfaces on the blank.

Abstract: A non-expansible linkage bracelet has a basic skeletal structure made up of interlocked sets of top and bottom links covered by decorative shells which also are interlocked with the top and bottom links.

Abstract: A quick disconnect assembly (20) provides for the releasable attachment of a fixture, such as a helicopter seat frame (26), to a support structure, such as the interior structure of the aircraft cabin (28). The assembly includes a tie down stud (100) having a substantially spherical outer surface (182) and a threaded bolt (188) extending therefrom for attachment to the support structure. An attachment fitting (22) is provided having a main body (40) with means for attachment (56) to the fixture. A plurality of grip arms (148) are pivotally associated with the main body. The arms have inwardly curved ends (156) for cooperating with the spherical outer surface of the stud to engage the stud by positioning the arms inwardly. With the attachment fittings secured to the tie down stud, the attachment fitting is movable relative to the stud through a predetermined angle.

Abstract: A fastener driving device such as a tacker, including a silicon-controlled rectifier (SCR) actuating circuit for producing a power stroke for substantially a complete half cycle of an AC potential supply and which occurs following the actuation of a switch actuable at random times with respect to the cycles of the AC supply. The circuit features three functional stages. A firing synchronizer circuit is provided to inhibit firing at other than the beginning or end of a half wave cycle of rectified AC potential. A memory supporting circuit provides a high degree of switch bounce immunity. A protecting circuit prevents an accidental and undesirable firing of the SCR that might otherwise automatically occur when a sudden increase of voltage occurs at its anode such as might occur when power is first applied to the actuating circuit.

Abstract: A fastener driving device such as a tacker, including an actuating circuit for producing a power stroke for substantially a complete half cycle of an AC potential supply and which occurs a fixed number of cycles following the actuation of a switch actuable at random times with respect to the cycles of the AC supply. The circuit features a decade counter clocked by the AC supply. One of the decade count outputs of the counter provides a signal for firing an SCR in series circuit with a solenoid for powering the tool. The counter is wired in circuit so as to latch at a predetermined count higher than the count output from which the firing signal is taken. Actuating the switch causes the counter to reset to zero, after which it counts positive half-cycles of the AC. When it reaches the count corresponding to the output from which the firing signal is taken, the tool is actuated. The counter continues to count until it relatches. It remains at the latched count until the switch is again actuated.

Abstract: There is disclosed in a surface effect ship which is constructed substantially of aluminum alloy material a hull construction including a side hull component which is bottomed by an operationally "wet" aluminum alloy keel plate, an improved propeller support arrangement comprising a superior strength thin-profile steel alloy strut extending cantilever-wise through the keel plate and carrying at its outer end bearing means for support of a ship propeller shaft. Interiorly of the side hull the steel strut is mechanically anchored to an operationally "dry" aluminum alloy member of the side hull structure, while at its underwater "wet" intersection with the aluminum alloy keel plate it is supported thereby but electrolytically and dynamically insulated therefrom by means of an epoxy-like housing device which at that cantilever support juncture encircles the strut.

Abstract: There is disclosed a surface effect ship stern seal system comprising a plurality of side-by-side vertically standing inflatable fingers of open top form, the leading end portions of the fingers being attached to the hull by resilient means and the bottom edges of the sidewalls of the fingers being closed by water planing plate means. The upper edges of the sidewall portions of the fingers are carried by tension ropes connecting at their leading ends to said resilient means and at their aft ends to the ship hull, reclining therebetween in catenary fashion.

Abstract: There is disclosed a wire clamp assembly for a terminal member of the type including a fastener member and a clamping member. The clamping member including a plate-like washer having a central aperture for receiving said fastener to be urged thereby toward said terminal member. The surface of the washer facing the terminal member has rib means formed thereon which are disposed substantially radially with respect to the axis of said aperture. Said rib means define at least two spaced apart protruding surfaces proximate at least one side of said washer, each said surfaces including a pair of edges for bitingly engaging a wire to be retained substantially simultaneously in multi-point contact in response to advancement of said washer toward said terminal member by said fastener.