Abstract:
A pipe has an innermost layer, outside of which there is an inner electrode layer, outside of which there is an insulating layer, outside of which there is an outer electrode layer. The innermost layer is made of plastic by continuous extrusion and the insulating layer is made of foamed plastic.
Abstract:
Film of dielectric material, which film contains gas bubbles preferably of a flat shape. To achieve improved electrical properties, the film is given a large internal unipolar charge, which is created by charging the film by means of an electric field intensive enough to produce partial discharges in the gas bubbles and to cause the charges to move into the dielectric material of the film.
Abstract:
The invention relates to a method and an apparatus for sound processing, where sound is attenuated by measuring it and by producing with an actuator a sound field of opposite sign in view of the original sound field. A desired value signal (I) is supplied to the actuator which reproduces the signal. To the actuator is attached a sensor, measuring sound pressure, and the difference of the sensor signal (B) and the desired value signal (I) is applied as high gain feedback to the actuator. As a consequence, sound not pertaining to the desired value signal (I) can be attenuated in a simple manner, and sound in accordance with the desired value signal (I) can be produced simultaneously with the same apparatus.
Abstract:
A method of steering an aircraft, and an aircraft comprising a supporting structure, at least one utility space, at least two propellers whose axles are arranged horizontally, and a driving mechanism to rotate each propeller. The blade angles of at least one propeller of the aircraft are adjusted as a function of a rotation angle of the propeller such that the blow power of the propellers provides the aircraft with a lifting force, and after take-off of the aircraft the blade angles of the propellers are adjusted such that the blow power of the propellers provides the aircraft with horizontal flight.
Abstract:
A method and an apparatus for treating waste material. The apparatus has a conical rotatable rotor (3) placed between stators (1, 2). At least the stators (1, 2) have recesses (9) from which the material in the apparatus can be discharged when the rotor (3) is rotating. The rotor (3) has several openings (8a, 8b) in the axial direction of the apparatus through which openings at least some of the waste material passes. The edges of the recesses (9) and the openings (8a, 8b) of the rotor (3) are sharp so that the waste material supplied to the apparatus is ground by means of the sharp edges when it passes through the openings (8a, 8b).
Abstract:
An apparatus for molding plastic including: (a) an injection space; (b) forming apparatus for supplying plastic material to the injection space, the forming apparatus having at least an inner conical stator and an outer conical stator and at least one rotatable rotor disposed outside of the inner conical stator; and (c) a piston for compressing the plastic material supplied to the injection space into a mold to form the plastic material into a shape determined by the mold.
Abstract:
A method for manufacturing an extrudable product including the steps of (a) providing an apparatus including an extruder having at least one rotor with first grooves, at least one stator with second grooves and a clearance between the rotor and the stator, the first grooves, second grooves and clearance forming a processing cavity having a volume that is equal to the volumes of the first grooves, the second grooves and the clearance, the processing cavity having a cross-sectional area that decreases continuously along at least a part of an axis of the extruder, the extruder further having a supply for feeding a material to be extruded into the processing cavity; b) feeding the material to be extruded in a powder, pellet or granuate form into the processing cavity through the supply and causing rotation of the rotor relative to the stator such that the material is forced to proceed along an x-axis in a shear zone of the extruder where the material is subjected to a shear which causes a fictional heat that melts a part of the material and forms a bed of mainly unmelted particles and melt around the particles, the processing cavity being completely filled at a cross-sectional portion thereof that is a distance from the end of the extruder, the unmelted particles being present in the cross-sectional portion in an amount sufficient to increase a pressure in the extruder to a level that is higher than that needed for pushing the material further along the x-axis to a die.
Abstract:
An extruder according to the invention comprises at least two annular conical feed gaps (9) one within the other, formed between a rotatable rotor (1) and a stator (4, 5). At lest some of the material to be extruded is subjected in the different feed gaps (9) of the extruder alternately to a higher pressure and then to a lower pressure. The rotor (1) or stator (4, 5) between the feed gaps (9) can then be balanced such that the pressure effect provides a hydrodynamic bearing, whereby, when the extruder is used, even at worst a very small force is exerted on the other bearings of the rotor (1) or stator (4, 5). By the method of the invention, a product can also be produced which contains cross-linked and at least partly oriented polyethylene.
Abstract:
A multi-layer reinforced and stabilized cable construction comprising a core portion (1, 11) and a non-metallic sheathing portion having barrier and protective layers and two or more outer reinforcement layers. In order for the mechanical and barrier properties of the cable to be controlled, the barrier and protective layers and/or the reinforcement layers (12, 13) are oriented in a controlled manner at different angles by fibrous reinforcements or lamellar barriers.
Abstract:
The invention relates to a device and a method for generating a force and/or a movement. The force and/or the movement are generated or the energy of the force and/or the movement is stored by utilizing a magnetic field. The magnetic field is generated with a charge current circuit (4) including a charge part and a structure generating the magnetic field without a separate winding. The charge current circuit (4) is used either to generate the magnetic field producing the force and/or the movement, or the force and/or the movement generates a variable magnetic field, the current induced by which is conducted to the charge part of the charge current circuit (4).