Abstract: A drive shaft including a universal coupling is made in the form of a uniy bonded fiber material structure having anisotropic properties. A winding form or mold is assembled to include, for example, an elongated winding sleeve, a flange forming core element, and an elongated winding mandrel joined together. Impregnated fiber material is wound onto the mold so that the fibers of the winding lie at thread angles approximately .+-.45.degree. with respect to the longitudinal axis of the form or mold. The wound structure is compressed whereby the coupling assumes its intended shape after curing or hardening. Portions of the form or mold are removed, for example, by dissolving and washing in a suitable solvent. Alternatively the drive shaft coupling is formed directly on the torque transmitting shafts to be coupled so that the transmitting shafts are integrated into the unitary structure. The annular flange and 45.degree.

Abstract: The neck of a hingeless helicopter rotor wing blade is provided with a damping device effective to dampen lead-lag movements of the rotor wing blade. For this purpose the damping device comprises at least two stiff plates secured to opposite sides of the blade neck by a plurality of elastomeric members glued or bonded to the respective stiff plate and to the blade neck at spaced intervals. The difference of deformation between the stiff plates and the blade neck causes a deformation of the individual members in directions substantially across the longitudinal blade direction (in lead-lag plane). The spacings between adjacent members are located where the damping action is inherently low.

Abstract: Mold bodies, for example, for the wings of rotary wing aircraft are formed y densifying a core of a hard foam material under such pressure and temperature conditions that later, when the core is placed into a mold together with the cover layer of a heat curable synthetic material, the core will expand again in response to heating the cover layer to its curing temperature. This expansion causes an intimate, complete bond between the core and the cover layer.

Abstract: A defective object such as a vehicle normally movable on a lane, assembly ne, or track is detected by a receiver on another object travelling behind the defective object, to avoid rear end collisions with the defective vehicle. For this purpose the vehicles are equipped with a signal receiver and with a signal damping member. The signal is transmitted in a transmission line extending along the lane, assembly line, or track. When a defect occurs, the damping member is moved into a position relative to the transmission line in which the damping member sufficiently dampens the signal so that the next following vehicle fails to receive the signal whereby a warning may be provided that the path ahead is not free or that it is blocked.

Abstract: The present optical element for an astable laser resonator includes a subate of a material which is transparent to the respective laser radiation. In manufacturing the present optical element the substrate is ground and polished on both surfaces and a template or mask is secured to one surface of the substrate. The mask has a mathematically computed boundary configuration which provides a diffraction limited divergence for the finished optical element. In the areas not covered by the mask a highly reflective coating is applied, for example, by vapor deposition. The substrate area which is not covered by the highly reflective coating remains transparent to the laser radiation. Thus, the element is useful as the reflector and/or as a lens in an astable laser resonator.

Abstract: The noise of an exhaust gas flow of an internal combustion engine or other hermodynamic equipment is reduced by silators which are operatively arranged for deadening or absorbing the exhaust noise. Such silators have vaulted surfaces enclosing an evacuated volume which may include a cooling liquid. The silators have a resonance frequency that depends on the vaulting height and the free span or diameter of the vaulted surface. By properly dimensioning the silators and combining a plurality thereof each having a different resonance frequency, a wide frequency range of exhaust noises may be covered. Preferably the silator impedance is smaller than the air impedance of the environment. The silators are protected against the heat of the exhaust gases.

Abstract: A noise reducing resonator, herein referred to as a silator due to its no silencing quality, is made up of primary struts forming a main frame and secondary struts forming at least one subframe enclosed by a vacuum tight cover to enclose a vaulting evacuated volume. Each frame has a given span width and a vaulting height corresponding to 0.005 to 0.05 times the respective span width. The frames are arranged in a hierarchic order which means that a larger main frame holds a smaller subframe which in turn holds a still smaller subframe and so on. The resonance frequency increases with the number of subframes held in a main frame. Interconnected silators may cover entire surface areas for noise reduction or absorption.

Abstract: The present endoscopic apparatus with a laser light conductor is used for irradiating bladder tumors in man with a laser light beam. For this purpose a jacketed light conducting fiber is arranged in parallel to an optical viewing device. A rigid bushing is secured to the output end of the light conducting fiber. The bushing includes a hinging member connected to a push rod or cable pull for remote manipulation of the output end of the light conduct ng fiber. Preferably, the light conducting fiber is axially shiftable in its jacket. For this purpose a shifting device, located at the input or operating end of the apparatus is operatively connected to the light conducting fiber.

Abstract: Windings of fiber compound materials are produced on a core in multicourses hereby the fiber arrangement may change from course to course. For this purpose a plurality of fiber coil carriers are arranged in sequence one after the other as viewed in the direction of core advancement. The fiber coil carriers are arranged coaxially relative to the core. The coils of fibers are supported by the fiber coil carriers. The r.p.m. of each fiber coil carrier is adjustable independently of the r.p.m. of any other coil carrier. Each r.p.m. is adjusted to be inversely proportional to the desired pitch of the fibers in the respective winding course. The direction of rotation of each coil carrier is also selectable independently of the rotational direction of any other coil carrier.

Abstract: The present weapons system enables an aircraft to attack simultaneously a urality of targets in an aimed, guided manner by a like plurality of small missiles or projectiles. For this purpose the missiles are carried in a rotatable drum type platform comprising respective launching tubes. The firing control system of the aircraft includes a computer which takes into account automatically the target coordinates and other data for selecting that missile which is most suitable for a particular target, whereby the rotatable platform requires a minimum of rotation for aiming the missile with a proper lead factor at the respective target. The missile is then automatically fired without any need of the aircraft heading toward the target.

Abstract: A low temperature tank is suspended in an outer shell or container by a pality of straps of fiber compound materials. Each strap comprises a plurality of individual strap elements arranged in series. The strap elements are made of different fibers whereby the strap element closest to the tank is made of a fiber material having the lowest heat expansion coefficient as compared to the heat expansion coefficient of the other elements of a strap further away from the tank. Preferably the strap elements are thermally insulated from each other. In that case the strap elements need not necessarily be made of fiber materials having different heat expansion coefficients.

Abstract: The present four-blade rotor is made up of two blade pairs, each blade pair aving two rotor blades arranged diametrically opposite one another. The blades of each blade pair are coupled to each other by means of a coupling loop for taking up centrifugal forces produced by the rotation of the blades. The present rotor system also has a centering device including a centering body and tension straps for each coupling loop. The tension straps connect the respective loop end to the centering body whereby the two coupling loops may be centered in the rotor head practically without play and without substantially limiting the free movement of the coupling loops.

Abstract: A plurality of lightweight sheets or panels are assembled to form a solar generator, especially for space craft. The panels or sheets which carry the solar cells, are made of fiber compound materials and are secured to a frame structure made of lightweight tubular members. Tensioning elements are operatively interposed between the frame structure and the panel sheets. The corners of the frame structures are provided with connecting elements so that several frames may be interconnected to form still larger assemblies. These assemblies may be folded and unfolded as desired.

Abstract: The present hingeless rotor system for helicopters has carrier spars or b each of which is subdivided into three functional sections substantially forming the blade neck connecting the lift producing portion of the respective rotor blade to the rotor mast. The carrier spar sections form a single structural blade neck member extending for about two tenths of the rotor radius from the rotor mast to the lift producing blade portions. About one half of the length of the blade neck adjacent to the rotor mast form the connecting zone proper. The spar sections comprise bands forming respective loops in the connecting zone proper. Two of the band loops are connected one above the other and a third band loop is displaced in the direction of rotation of the rotor from the first mentioned band loops. The third band loop is releasably connected to the rotor mast to allow a folding of the respective rotor blade. The spar sections are interconnected by shear resistant bridging webs having a T- or X cross-section.

Abstract: A receiver for solar power stations comprises a plurality of parabolic mirs combined with spherical collectors located substantially in the focal point of each mirror. These spherical collectors form absorbers which may be connected in series and/or in parallel with each other.

Abstract: A tacking rivet has a shaft and a head with a longitudinal bore through the haft and through the head. The head forms a rim extending radially outwardly and the rim or head has a divider which divides the head and/or rim into at least two portions. The divider may, for example, be a slot or recess or indentation.

Abstract: The synchronism or tracking between two analog signals is compared by a cuit arrangement having two inputs to which these analog signals are applied. A comparator circuit compares the two signals and provides a trigger or energizing signal to a switch which in turn produces an error signal when the two compared signals deviate from each other to an extent larger than a predetermined limit. One input is connected to the comparator circuit through a heterodyning circuit wherein the respective analog signal is heterodyned by a heterodyning signal which varies in its polarity. The comparator circuit includes a polarity detector which provides a signal signifying a positive or a negative difference between the amplitudes of the two polarity signals. A discriminator circuit is operatively connected to the comparator to provide a switch energizing signal when the difference signal does not have any zero transitions or passages with the frequency of the heterodyning signal.

Abstract: This protective coating on a metal surface, especially for aircraft bodies nd the like, has, on a pickled metal surface which may be anodized in addition to being pickled, a bonding primer layer and a polyurethane primer layer, an intermediate layer which is easily dissolved and a top layer forming a finish coat on said intermediate layer which protects the primer layers when the top coat is removed for a new paint job.

Abstract: Explosive decompressions in an aircraft or in a spaceship are controlled in individual rooms or compartments thereof by including in the walls, which separate these rooms or compartments, zones or boundaries of such zones which have an inherent rated or predetermined breaking characteristic whereby these zones or boundaries may break in one or the other direction depending on which compartment the decompression started.

Abstract: The present aircraft steering method makes use of additional lift gained by ontrolling the separating of vortical flows from the leading edges of the wings for the purpose of controlling the aircraft about its pitch axis, its roll axis, and its yaw axis. The vortical flows are selectively or differentially separated from the leading edge of the wings by raising or lowering leading edge flaps and/or blowing a flowing medium over the wing surfaces substantially in parallel to the leading edge.