Abstract: A friction-welding device for the integral joining of components, having an oscillator, which generates a periodic movement of a component and a welding surface provided thereon relative to another, static component and a welding surface provided thereon, with directions of movement parallel to the welding surfaces, having a compression device which presses the welding surfaces together, and a cartridge which accommodates the moved component. The oscillator includes two or a greater, even number of piezoactuators, which are arranged in pairs on a line of application and are able to be prestressed with respect to the cartridge from opposite sides under pressure generation and are able to be moved in a synchronous, oscillating manner together therewith and the component.

Abstract: A deformable aerodynamic profiled member has a front profile area and a rear profile area in the outflow area. It is bounded by shells on the pressure side and/or on the suction side, converging in a rear profile edge (6). D33 piezo actuators are provided in at least some locations for deformation of the profiled member. The piezo actuators are aligned such that their length changes essentially in the direction of the planes of the shells when acted upon by electricity.

Abstract: The invention relates to a linear, hydraulic pivot drive, especially for the flap control system of aerodynamic structures. Said pivot drive comprises a housing provided with ports for introducing a hydraulic medium, a piston which is arranged inside the housing and can be axially displaced by the effect of the hydraulic medium, and an output shaft which is provided with coarse threads and interacts with the piston in order to cover the axial displacement of the piston into a rotational movement. The invention is characterized in that the output shaft is integrated into the piston, the coarse threads running in the same direction and engaging in the piston, and the cross-section of the piston has a spline profile for effectively preventing a rotational movement of the piston.

Abstract: The invention relates to a linear, hydraulic pivot drive, especially for the flap control system of aerodynamic structures. Said pivot drive comprises a housing provided with ports for introducing a hydraulic medium, a piston which is arranged inside the housing and can be axially displaced by the effect of the hydraulic medium, and an output shaft which is provided with coarse threads and interacts with the piston in order to cover the axial displacement of the piston into a rotational movement. The invention is characterized in that the output shaft is integrated into the piston, the coarse threads running in the same direction and engaging in the piston, and the cross-section of the piston has a spline profile for effectively preventing a rotational movement of the piston.

Abstract: A form-adaptable electrode structure in layer construction includes at least two conductor layers, between which an insulating layer is disposed, the conductor layers having first and second electrode strips arranged in each case in parallel, and the electrode strips of the first conductor layer being arranged at an angle with respect to the electrode strips of the second conductor layer, so that a net-like structure is formed, and the first electrode strips of the first conductor layer being conductively interconnected with the first electrode strips of the second conductor layer, and the second electrode strips of the first conductor layer being conductively interconnected with the second electrode strips of the second conductor layer via the insulating layer at intersections of the net-like structure.

Abstract: It is the object of the invention to create a piezoelectric expansion actuator for d33 piezoelements, which allows vibrations in structures to be suppressed. This object is achieved pursuant to a solution of the invention in that the expansion actuator (1) comprises a piezoelectric stack (2), which consists of d33 piezoelectric elements and is arranged between output elements (4), which are attached to the surface of the structure (7). The invention applies to a piezoelectric extension actuator, which is used to control vibrations in structures.

Abstract: A piezoelectric actuating device for controlling a flap on a rotor blade of a helicopter includes a piezo element arrangement including at least one piezoelectric stack actuator. A power transmission frame is coupled to the piezo element arrangement, the power transmission frame including an abutment and a driven element and generating a force therebetween from a change in length of the piezo element arrangement upon an excitation thereof, the force acting transversely to a direction of a centrifugal force of the rotor blade. A first holding device is provided including a pair of first flexible straps configured to fix the power transmission frame relative to the rotor blade in the direction of the centrifugal force and to allow the power transmission frame to move relative to the rotor blade transversely to the direction of the centrifugal force within a limited range.

Abstract: The invention relates to a piezoelectric actuating device for controlling the flaps on the rotor blade of a helicopter. The inventive device comprises a piezo element arrangement (2) and a power transmission frame (10) which is coupled therewith, is fixed to the rotor blade and generates a force between an abutment (14) and a driven element (13) by changing the length of the piezo element arrangement (2). Said force is effective crosswise in relation to the direction of the centrifugal force of the rotor blade. According to the invention, a first holder (11, 12) which fixes the power transmission frame (10) to the rotor blade in the direction of the centrifugal force and is flexible crosswise in relation to the direction of the centrifugal force and a second holder (15, 16) which fixes the abutment (14) that is provided on the power transmission frame (10) crosswise in relation to the direction of the centrifugal force and is flexible in the direction of the centrifugal force are provided.

Abstract: A ligand layer on a metal surface is capable of being reversibly switched between adhesion and deadhesion. The ligand layer includes substituted pyridine dimers and/or pyridine trimers which are selected from the group consisting of: with R1 through R6 being able to be equal or different and being selected from the group consisting of —R—CH(O)CH2, OH, —O—R, NR2, NHR, NH2, CO2H, CO2R, R and H. R is selected from the group consisting of alkyl and aryl residues with the proviso that not all residues R1 through R6 are hydrogen atoms at the same time. R7 is selected from the group consisting of —R—CH(O)CH2, OH, —O—R, NR2, NHR, NH2, CO2H, CO2R, CONHR, R and H, with R being selected from the group consisting of alkyl and aryl residues. Y is selected from the group consisting of silicon, carbon, nitrogen, phosphorus and oxygen atoms, and X is an oxygen, sulfur or phosphorus atom, and n having the value 0 or 1.

Abstract: Body or structural noise transmitted through a connector such as a strut, that connects a noise source, such as an engine, to an enclosure, such as a passenger cabin or cell of a helicopter, is suppressed by at least one piezoactuator which is excited to counteract any vibrations of the strut caused by body noise so that body noise vibrations are cancelled or at least substantially suppressed. The excitation of the piezoactuator is controlled in closed loop fashion in response to feedback signals from a sensor secured to the connector.

Abstract: A tilt and swivel positioning device for positioning a servo flap in a rotor blade. The device contains a tilt element and a bearing element. The tilt element is swivellably attached to the bearing element. The bearing arrangement has a convex roll-off surface resting against a concave roll-off surface. The radius of the concave roll-off surface exceeds the radius of the convex roll-off surface.

Abstract: A method for reversibly switchable cross-linking of monomers includes cross-linking the monomers by adding complexable metal ions to form a polymer, and bond-breaking the polymer formed by applying a direct voltage, by changing the pH value or by changing the temperature. The monomers include compounds of the general formulas R1 through R6 may be equal or different and are selected from the group consisting of H, OH, —NX2, —OX, —SH, and —SX, with X being selected from alkyl and/or aryl groups which are terminally substituted by reactive residues selected from the group consisting of OH, —CH(O)CH2, —NCO, —COOH and NZ2. Z is selected from the group consisting of alkyl groups, aryl groups and a hydrogen atom, one of the groups Z being a hydrogen atom with the proviso that not all residues R1 through R are hydrogen atoms at the same time.

Abstract: A piezoelectric actuator has at least two piezoelectric actuator elements connected in series with each other mechanically and electrically and form a half bridge in an amplifier bridge circuit having a further half bridge formed by two series connected electronic switches which are operated or clocked by a control circuit such as a pulse modulator circuit for periodically energizing the piezoelectric actuators in push-pull fashion. A choke (22) is connected between the junction point (JP1) of the two piezoelectric actuators and the junction point (JP2) between the two electronic switches (23, 24) for assuring a loss free reverse charging of the two piezoelectric actuators functioning as electrical capacitors in the energizing bridge circuit (21). The choke 22 functions as an energy storage and the stored energy is used in the push-pull charging of the capacitors (19, 20) formed by the piezoelectric elements.

Abstract: An aerodynamic component such as a helicopter rotor blade has an aerodynamic flow profile, a free end and a mounting end forming a blade root for attachment to a rotor mast. A blade section between the root and the free end has a leading edge and a trailing edge as viewed in the flow or chord direction. The blade is enclosed on its suction side and its pressure side with a respective skin. A nose flap or leading edge flap is secured to the leading edge by a bearing or hinge. The blade tilting angle is adjustable by piezo-drive elements arranged in at least one pair forming an actuator for each nose flap. The piezo-elements of a pair are arranged in the chord direction one behind the other and the pair is secured to the body of the blade by a fixed point positioned between the elements of a pair. The expansion and contraction from the piezo-element closer to the trailing edge is transmitted to the flap by a push rod.

Abstract: A piezoelectric actuating drive is calibrated so that displacements or movements of its actuator output beam (4) become independent of environmental operating conditions and of piezoelectric instabilities. For this purpose an automatic determination and correlating of energizing signal values and respective displacement positions of an actuator beam (4) are performed on the basis of first sensing or measuring striking times (t1, t2) when the actuator beam (4) encounters at least one, preferably two limit stops which limit the beam displacement caused by piezoelectric action. The change of the electric capacitance of a piezostack (3) that displaces the actuator output beam (4) is measured when the beam (4) strikes a limit stop. Instead of measuring a change in the electric capacitance of the piezostack (3), electric charge impulses may be measured at the time (t1, t2) and evaluated for the correlation between the energizing control or input signal and the corresponding output beam displacement.

Abstract: A ligand layer on a metal surface is capable of being reversibly switched between adhesion and deadhesion.

Abstract: A device directed to a continuous control of piezoelectric actuators for fuel injection systems. A piezoelectric actuator is provided for controlling the valves of i.c. engines with a constant actuator function under different conditions of use and operation. The electrical manipulated variable is a length-changing electrical charge transmitted to the piezo stack that is generated by a charge generator and is controlled in reference to the charge by a control unit. The use and operation conditions of the i.c. engine acting on the piezo actuator are detected by sensors and fed to the control unit to parameterize the charge control. With these features, a continuous control of a piezoelectric actuator in a fuel injection system for i.c.

Abstract: An actuator device (2) includes a piezoelectric or electro-strictive solid state actuator element (6) that is elongated upon application of an electric voltage thereto, and a transmission mechanism (8) that amplifies the stroke displacement of the actuator element. The transmission mechanism (8) includes a plurality of rigid frame members (12), including unitary frame members (12.1, 12.2) and divided frame members (12.3), and elastically flexible joints (10) that respectively interconnect the frame members. Each one of the divided frame members (12.3) is made up of a plurality of separate parallel link rods (16). Each flexible joint (10) is made up of a plurality of individual parallel hinge members (18) that respectively connect an end of each one of the link rods (16) to the adjacent unitary frame member (12.1, 12.2).

Abstract: A method for reversibly switchable cross-linking of monomers includes cross-linking the monomers by adding complexable metal ions to form a polymer, and bond-breaking the polymer formed by applying a direct voltage, by changing the pH value or by changing the temperature.

Abstract: A piezoelectric actuator has at least two piezoelectric actuator elements connected in series with each other mechanically and electrically and form a half bridge in an amplifier bridge circuit having a further half bridge formed by two series connected electronic switches which are operated or clocked by a control circuit such as a pulse modulator circuit for periodically energizing the piezoelectric actuators in push-pull fashion. A choke (22) is connected between the junction point (JP1) of the two piezoelectric actuators and the junction point (JP2) between the two electronic switches (23, 24) for assuring a loss free reverse charging of the two piezoelectric actuators functioning as electrical capacitors in the energizing bridge circuit (21). The choke 22 functions as an energy storage and the stored energy is used in the push-pull charging of the capacitors (19, 20) formed by the piezoelectric elements.