Abstract: An insert filter 10 for cleaning a gas stream, particularly for the intake air of an internal combustion engine or an air-conditioning unit, which includes a filter frame 11, a filter element 12 placed in the filter frame 11, and a shaft cover 13 and which is placed in the shaft 14 of a duct system 15 that guides the gas stream such that an unfiltered side 16 is separated from a clean side 17 by the filter element 12 and the filter frame 11. The shaft cover 13 closes a shaft opening 24 through which the insert filter 10 is inserted in the shaft 14. The filter frame 11 is connected to the shaft cover 13 so that the filter frame 11 can be removed from the shaft 14 without any need for additional removal aids by simply pulling on the shaft cover 13.

Abstract: A cotton harvester which includes at least one cotton picker unit for harvesting cotton from plants planted in narrow, parallel rows. The cotton picker unit comprises a cotton picker housing that supports a lateral plant lifter which extends forward of the housing and defines a plant row channel for receiving cotton plants planted in a row. The plant channel extends back into the housing to a plant compressor sheet which facilitates the picking of the cotton from the cotton plant by a picker rotor which is supported in the housing adjacent to the plant row channel and traverse to the compressor sheet. A doffer column also supported in the housing is near the picker rotor and removes the picked cotton from the picker rotor and moves the cotton towards an outlet and through an exhaust chute for receiving the cotton. The cotton is then collected in an appropriate cotton basket.

Abstract: Machine for harvesting tree fruit comprising two parallel, vertical gantries joined at the bottom of their vertical side arms by longitudinal frames extending inward from the insides of the arms and joining the two arms on one side. A duct receives fruit conveyed by a screw container, to an end of the duct with a peeler. A rear storage container for peeled fruit is placed after the peeler. The two frames are separated by a distance slightly greater than the width of the trunk of the trees to be harvested. A longitudinally movable clamp for clamping a tree to be shaken is movable along a longitudinal guide on one of the frames. A feeler supported on one frame contacts the tree and activates the clamp to shake the tree.

Abstract: The invention relates to a harvesting machine, especially a self-propelled pick-up chopper for picking up and chopping corn, wilted grass, green feed and similar harvested material, with a chopper device disposed after pick-up and feed organs. The chopper device comprises a chopper drum (1) with cutting tools (3) disposed in the circumferential direction of the chopper drum (1) at a distance from one another. In order to be able to make available a harvesting machine with an advantageous vibrational behavior and lower power requirements, the cutting tools (3) are constructed with an overlapping dimension “U” with respect to the cutting tools disposed ahead and behind in the circumferential direction.

Abstract: A baler for making rectangular crop bales has a generally horizontally disposed fore-and-aft extending baling chamber. The pickup of the baler is disposed underneath the baling chamber in line with the path of travel of a reciprocating plunger in the overhead chamber. An in-line transfer duct leads generally upwardly and rearwardly from the pickup to the bottom of the chamber. An enclosed crop flow passage is defined from a point immediately behind the pickup to a point located at the opening in the bottom of the baling chamber and presents a forwardmost cutting zone, a packing zone behind the cutting zone, and an accumulating zone behind the packing zone. Cutter apparatus within the cutting zone reduces the crop materials into smaller pieces as they flow through the cutting zone, whereupon a separate packer takes the materials from the rear side of the cutter apparatus and packs them in a downstream direction toward the accumulating zone where they form into a charge.

Abstract: A process for combining singles yarns, of different colors or dyeabilities, to form an apparent twist yarn. The process includes the sequential steps of individually and simultaneously drawing and texturing a plurality of singles yarns; converging the drawn and textured singles yarns through an air jet entangler that simultaneously entangles and tensions the yarn bundle; twisting the singles yarns in the yarn bundle about each other in alternate, or otherwise patterned, S and Z directions.

Abstract: A cable drag chain includes a plurality of ring-like inner links pined together at front and rear ends thereof. Each of the inner links has opposite end faces serving as stopper surfaces engageable with the stopper surfaces of the adjacent inner links to limit the angle of pivotal movement between the adjacent inner links. A ring-like outer link is detachably mounted to a joint portion between two adjacent inner links and surround the joint portion so as to close a space formed between the two adjacent inner links.

Abstract: Provided is an engine having positive displacement chambers containing pistons and an external combustion chamber which utilizes the energy stored in compressed fuel and compressed air in combination with the energy released during combustion of the fuel to drive the pistons. Energy expended compressing the fuel and air are recovered.

Abstract: A gas turbine system comprises an alarm signal calculation circuit, a shutdown calculation circuit and a flashback-error signal prevention calculation circuit. The alarm signal calculation circuit, the shutdown calculation circuit and the flashback-error signal prevention calculation circuit are integrated in a combustion monitoring device for monitoring combustion condition of combustion gas in a gas turbine-combustor.

Abstract: The present invention relates to steam generating systems in a combined cycle plant that is comprised of a gas turbine section that is operatively coupled to a steam cycle section to produce mechanical energy for electrical power generation, or for other purposes. In one embodiment, a gas diversion valve between the gas turbine section and the steam cycle section diverts at least a portion of the hot combustion gases generated by the gas turbine section to the steam cycle section, thereby augmenting the heat available to the steam cycle section. In another embodiment, steam produced within the steam cycle section is communicated to at least one of the turbines in the gas turbine section to augment the power output of the plant. In yet another embodiment, the steam cycle section may be selectively altered to allow the plant to accommodate the various tasks associated with sugar cane processing.

Abstract: Gas turbine system is constructed such that no fuel gas compressor is used and a turbine is operated at low temperature so that a life of the system is elongated and the safety is enhanced. Air compressed at a compressor (11) of about 200° C. enters a heat exchanger (12) to be heated by combustion gas to about 760 to 900° C. to enter the turbine (13) and to work to rotate a generator (15). Exhaust air of the turbine (13) of which temperature is lowered to about 500 to 750° C. is supplied into a combustor (14) for fuel combustion to generate high temperature combustion gas of about 800 to 950° C. This combustion gas enters the heat exchanger (12) to heat the air from the compressor (11). The air is heated by the high temperature combustion gas with no fuel gas compressor being used and the turbine is operated by the lower temperature air as compared with a conventional case. Hence, the system is made less expensive, the life is elongated and the safety is enhanced.

Abstract: An engine control system includes an adaptive bias sub-system (100) that generates bias values for controlling the air-fuel ratio. The sub-system (100) includes an integral controller (118) that reads an error signal from a post-catalyst switching EGO sensor (112). A plurality of noise isolation integrators (122) filter any noise resulting from a particular engine operating condition (e.g. acceleration, deceleration, idling) from the integrated error signal and stores the signal in a corresponding keep-alive memory (124) as a bias value for that engine operating condition. In a preferred embodiment, the post-catalyst feedback loop includes a gated proportional controller 116 that turns on for a limited period of time after the post-catalyst switching EGO sensor (112) switches states.

Abstract: The values of parameters of a model of an object exhaust system including a catalytic converter are identified from the data of outputs from an air-fuel ratio sensor and an O2 sensor which are disposed respectively upstream and downstream of the catalytic converter while an internal combustion engine associated with the catalytic converter is in operation. A deterioration evaluating parameter representing the degree of variation of time-series data of the identified parameters is determined from the time-series data of the identified parameters. The deteriorated state of the catalytic converter is evaluated based on the deterioration evaluating parameter.

Abstract: The present invention has its object to judge the establishment of conditions influencing on the evaluation of performance of a NOx catalyst, whereby when being established, the evaluation of performance of the NOx catalyst is stopped to thereby prevent the performance of the NOx catalyst from being erroneously judged.

Abstract: A forced stoichiometric combustion is executed every time a cumulative travel distance of a vehicle increases by a distance, thereby creating an opportunity to determine an air-fuel ratio value in a region in which a rich spike control is performed. Therefore, the determination of an air-fuel ratio value can be precisely calculated so that the air-fuel ratio value corresponds to a value that reflects a deviation of the actual air-fuel ratio and a proper value. Accordingly, it becomes possible to control, with high precision, correlation between the air-fuel ratio and a proper value based on the determined air-fuel ratio value during a fuel-rich combustion that is caused by the rich spike control.

Abstract: A catalyst reduction system using diesel fuel as a reductant for vehicles equipped with diesel engines reduces NOx transient emissions produced during acceleration. Impending engine accelerations are sensed to produce metered pulse(s) of fuel oil simultaneously with and preferably in advance of, the NOx transient emission. The fuel pulse is sufficient in quantity to reduce the NOx transient emission when the NOx and HC resulting from the cracked fuel oil are present at spatially equal distances within the reducing catalytic converter. Optionally, the washcoat of the reducing catalyst is formulated to delay the adsorption/desorbtion of one of the gases on the washcoat to assure proper timing of the NOx transient and fuel pulse(s).

Abstract: In a fluid coupling with a baffle plate protruding on the side of an inner peripheral surface of a circulating circuit, a clutch chamber is defined between a back of a turbine impeller and a side cover covering the back of the impeller, to communicate with an outer periphery of the circulating circuit. The clutch chamber is divided by a clutch piston into an inner chamber portion on the side of the turbine impeller and an outer chamber portion on the side of the side cover. The clutch piston is axially movably connected to the turbine impeller, thereby constituting a lock-up clutch, so that a first oil passage leading to the outer chamber portion and a second oil passage leading to an inner periphery of the circulating circuit are put into alternate communication with a discharge portion of an oil pump and with an oil reservoir in a switched manner.

Abstract: A travel motor hydraulic control system for a construction machine having a plurality of hydraulic pumps which supply individually pressurized fluid for a plurality of hydraulic travel motors and a plurality of flow control valves which control the flow rate of the pressurized fluid to be supplied to the motor during an ordinary work. A controller receives a control signal representative of a travel control lever stroke sensed by a position sensor and a control signal detected by a pressure sensor, determines if the vehicle is traveling up a slope, and transmits a command signal to a solenoid operated valve to move a pilot operated shut off valve toward a valve-closing position, thereby the travel hydraulic motors are individually supplied the pressurized fluid from the hydraulic pumps.

Abstract: A thermal cycle engine having a heat exchanger for transferring thermal energy across the heater head from a heated external fluid to the working fluid. The heat exchanger has a set of heat transfer pins each having an axis directed away from the cylindrical wall of the expansion cylinder. The height and density of the heat transfer pins may vary with distance in the direction of the flow path, and the pin structure may be fabricated by stacking perforated rings in contact with a heater head. Ribs are provided interior to the heater head to enhance hoop strength and thermal transfer.

Abstract: A master cylinder includes a cylinder housing having a rearwardly opening inner bore, a piston having a forwardly opening bore positioned in the inner bore of the cylinder housing, a spring disposed in the inner bore of the piston, a stopper supporting a front end of the spring, a retainer disposed in the inner bore of the piston and supporting a rear end of the spring, and a rod connecting the retainer and the stopper while allowing the spring to compress in the axial direction. A plurality of projection portions are formed on the outer circumferential portion of the retainer and the retainer is pressed into the inner bore of the piston via the projection portions.

Abstract: This invention aims to prevent a core from being pushed back when a hydraulic fluid is compressed by a high load occurring with a molding pressure of molten melt at a casting and pressing time in a core driving cylinder in a die cast machine.

Abstract: An internal combustion has an exhaust gas line, an exhaust gas heat exchanger through which exhaust gas withdrawn through the exhaust gas line passes so as to take heat energy, a heating heat exchanger to which the withdrawn heat energy is made available and which is connected to a cooling fluid circuit of the internal combustion engine, an exhaust gas turbocharger provided with a turbine housing and a turbine wheel rotatable in the latter, the exhaust gas turbocharger being arranged in the exhaust gas line, the exhaust gas heat exchanger being connected heat conductively with the turbine housing of the exhaust gas turbocharger for withdrawing of heat from the exhaust gas which passes through the turbine wheel.

Abstract: An air bottoming powertrain, suitable for use in automobiles includes an internal combustion engine, a compressor which receives gaseous working fluid and compresses it to an elevated pressure, a cooler for operating the compressor isothermally, an expander for deriving work from the compressed gas and a heat exchanger located in the compressed gas line for indirect heat exchange between the compressed working fluid and exhaust gas from the internal combustion engine. The expander may have a cylindrical barrel with a plurality of cylinders arranged in the circle and open at one end face of the cylinder barrel, which end face is sealed closed by a valve plate. The cylinder barrel and valve plate allow relative rotation therebetween to drive an output shaft, driven by compressed gas from the compressor. An alternative expander is a Scotch Yoke piston motor which includes plural paired and axially aligned cylinders on opposing sides of an output shaft.

Abstract: Water quality detecting points for detecting sea water leakage are provided at a portion in a hot well zone right under a tube bundle of heat exchange tube forming a steam condensing zone and at a condenser outlet allowing the condensate to be led out of the condenser or in the vicinity thereof, and a difference between detection values at both detecting points is monitored.

Abstract: Described is a method for reducing thermoacoustic vibrations in turbo machines with a burner system which provides at least one burner, into which burner is injected fuel through at least one burner nozzle, said fuel being mixed with the combustion supply air flowing into the burner and forming a fuel/air mixture that is ignited in a combustor following the burner system.

Abstract: A low cost teqhnique is disclosed for dissolving, liquefying and introducing CO2 gas into the deep sea for storage there, which involves low pressure and is simple in structure, easy to operate and maintain, safe, and relatively free of breakdown. The apparatus comprises a pipe for transporting a mixture of the CO2 gas and the seawater or other liquid, extending from above the sea or from the ground into the deep sea, a pump for moving the gas and a pump for moving the liquid, or a single pump for moving both the gas and the liquid, whereby the gas-liquid mixture is formed and introduced into the deep see through the same pipe, the CO2 gas in the mixture being pressurized, agitated, dissolved and liquefied during its transport through the pipe with the result that its bubbles are eliminated and buoyancy decreased, thereby making it possible to release the CO2 into the deep sea with a relatively small pumping force.

Abstract: A remote inspection device for a refrigerator receives information about an operating state of the refrigerator transmitted from the refrigerator via a communication network continuously or at predetermined intervals. The remote inspection device further inspects the refrigerator on the basis of the received information.

Abstract: A device for testing and diagnosing air-conditioning apparatus of a car in the preferred embodiment comprises an control unit (1), indicated as CPU and having a microprocessor; a first sensor (2) for measuring the low pressure LP upstream of the compressor; a second sensor (3) for measuring the high pressure HP downstream the compressor; a third sensor (4) for measuring the environment temperature Ta; a fourth sensor (5) for measuring the temperature Ti at the air outlet in the car; possible sensors of auxiliary temperatures (5a and 5b); a couple of connectors (6a, 6b) for measuring the voltage at the ends of the clutch cycling switch in orifice tube system with clutch cycling switch; a sensor of relative humidity (7); a data input unit (8), such as a keyboard; a unit (8a) for displaying the data, such as a alphanumeric LCD, and/or a printing unit (8b); a connector of type RS232 for communicating with a computer; an external memory unit (9), in particular a memory card, with relative interface.

Abstract: A vapor compression system having a line for flowing heat transfer fluid, a compressor and a condenser both connected with the line. The vapor compression system also has an expansion device connected with the line for expanding the heat transfer fluid. The expansion device has a housing defining a housing orifice and at least one ball within the housing. The ball forms at least two channels, wherein each channel defines a channel orifice. The effective cross-sectional area of the one channel orifice is greater than the effective cross-sectional area of the other channel orifice. Moreover, the ball is movable between a first position and a second position, wherein the housing orifice is effectively made larger in the first position than in the second position. The vapor compression system also has an evaporator connected with the line for transferring heat from ambient surroundings to the heat transfer fluid.

Abstract: Small sized air conditioner including a heat discharging part having a small sized compressor and condenser, a heat absorbing part having a small sized evaporator, a drain hose for transferring condensate from the evaporator to the heat discharging part, and a device for disposing of condensate fitted in the heat discharging part for vaporizing the condensate transferred through the drain hose by using a heat generated at the heat discharging part, thereby facilitating easy installation and movement.

Abstract: Personal air conditioner including a heat discharging part having small sized compressor and condenser, a heat absorbing part having a small sized evaporator, a flexible high pressure pipe line connecting between the condenser and the evaporator, and a flexible low pressure pipe line connecting between the evaporator and the compressor, thereby installation and moving of the heat discharging part and the heat absorbing part are convenient, to allow an intensive cooling of a particular space.

Abstract: Systems and methods are disclosed for the combined collection of freshwater from atmospheric humidity and cooling of closed spaces in hot and humid climates through collection and processing of water vapor condensate from air conditioning units and dehumidification and air-drying units. Components of air conditioning units are rearranged to allow outdoor air to go through the units to increase the condensate and hence freshwater production. Design modifications of dehumidifiers include separation of cooling and water condensation components from other components that radiate heat to enhance the cooling effects of dry air leaving the dehumidifiers. In addition, apparatus and methods are disclosed for adaptation of commercial dehumidifiers using gas refrigerants in providing ample freshwater quantities and comfortable space cooling.

Abstract: In order to magnify capacity control of a refrigeration cycle for an increased efficiency and achievement of compactness, the refrigeration cycle includes a compressor, a four-way valve, a heat exchanger on a side of a heat source, a liquid receiver, a heat exchanger on a side of use, and an electronic expansion valve, all of which are connected other by pipes, and comprises a refrigerant circulating in the refrigeration cycle and being a non-azeotropic refrigerant, a second liquid receiver for taking out a refrigerant vapor from an upper portion of the liquid receiver to condense and store the refrigerant, and a pipe connecting the second liquid receiver to the liquid receiver via a shut-off valve.

Abstract: Cryogenic tunnel for chilling products, especially food products, comprising a horizontal conveyor belt (1) for products and means for blowing a cold gas thereover and for limiting the escape of cold gas from the tunnel and/or the admission of external gas into the tunnel. The tunnel comprises at least one fan (2) placed above the conveyor belt, the blades of which extend transversely with respect to the belt over virtually the entire width thereof.

Abstract: Small air conditioner including a heat discharging part including a body having an air inlet in a side and an air outlet in a top surface, a condenser fitted close to an inside of the air inlet, a fan fitted under the air outlet, and a compressor fitted under the fan, wherein external air flows into the heat discharging part through the air inlet, heat exchanged at the condenser, cools down the compressor, and discharged through the air outlet, thereby permitting convenient installation and moving.

Abstract: The invention relates to a method for packaging carbon dioxide snow in a plastic film bag, in which method the following steps are employed:

Abstract: A process for removing hydrocarbons less volatile than methane from a pressurized liquid natural gas (PLNG). PLNG is heated in a heat exchanger, thereby vaporizing at least a portion of the PLNG. The partially vaporized PLNG is passed to a fractionation column. A liquid stream enriched with hydrocarbons (C2+ or C3+) less volatile than methane is withdrawn from a lower portion of the fractionation column and a vapor stream lean in the hydrocarbons less volatile than methane is withdrawn from an upper portion of the fractionation column. The withdrawn vapor stream is passed to the heat exchanger to condense the vapor to produce PLNG lean in hydrocarbons less volatile than methane.

Abstract: Hyperpolarizers which produce hyperpolarized noble gases include one or more on-board NMR monitoring coils configured to monitor the polarization level of the hyperpolarized gas at various production points in the polarized gas production cycle. A dual symmetry NMR coil is positioned adjacent the optical pumping cell and is in fluid communication with a secondary reservoir in fluid communication with the polarized gas dispensing or exit flow path. This can measure the post-thaw polarization of the gas “on-board” the polarizer. Alternately or additionally, a NMR monitoring coil is assembled to the exit port portion of tie optical pumping cell to give a more reliable indication of the polarization level of the gas as it flows out of the gas optical pumping cell. Another NMR monitoring coil can be positioned in a cryogenic bath adjacent a quantity of frozen polarized 129Xe to determine the polarization level of the frozen gas.

Abstract: A method to obtain a gaseous product by the low temperature fractionation of air includes supplying a first, purified and cooled stream of air to a high-pressure column. At least one liquid stream from the high-pressure column is passed into a low-pressure column. A product stream in the liquid state is drawn off from the low-pressure column and is brought to an elevated pressure. The product stream is then evaporated in an indirect heat exchange with a second purified stream of air. The second stream of air, which is condensed at least partly during the indirect heat exchange, is expanded at least partly in a work-producing manner. The second stream of air subsequently is passed into the low-pressure column. The pressure of the second stream of air at the outlet of the work-expansion is lower than the operating pressure in the sump of the high-pressure column. The work-expansion of the second stream of air is carried out in a single step.

Abstract: An assembly of rib structures sandwiched between a dielectric glass layer and a glass substrate for use in a flat panel display, such as plasma addressed liquid crystal (PALC) displays, is formed by a number of methods. One method includes molding thermoplastic glass frit containing paste into rib structures, transferring the rib structures to a thin transparent layer of a thermoplastic dielectric glass frit containing composition on a drum, and transferring the rib structures with the thin transparent dielectric glass layer to a glass substrate having metallic electrodes already formed thereon.

Abstract: The invention relates to a method for heating up and shaping a preform consisting of glass or glass ceramic.

Abstract: A vacuum refining unit wherein, with a vacuum pump connected via a suction line, a vacuum is created above a glass melt to be refined. A valve for supplying secondary air from the atmosphere, for maintaining the pressure conditions in the vacuum unit constant, branches off the suction line. Refining is improved because the vacuum circuit has a controllable leak which provides an inflow of secondary air as a function of different measuring values and thus provides constant refining conditions.

Abstract: A class preform (30) for making optical waveguides has surface impurities such as silicon carbide or silicon nitride. The preform is drawn in a furnace (12) that is supplied with oxygen via a conduit (40). The oxygen causes the impurities to oxidize and not effect the strength of the fiber.

Abstract: A dehydration and consolidation furnace and a dehydration and consolidation method in which gas in a chamber does not leak to a furnace body room and gas in a furnace body room does not leak into a chamber is provided. A furnace of one embodiment of this invention has first muffle tube 3 and second muffle tube 4. The second muffle tube 4 is arranged coaxially around the first muffle tube 3. An optical fiber preform is arranged in this furnace. During the dehydration and consolidation process the pressure of the intermediate room 10 is set lower than a pressure inside the first muffle tube and outside the second muffle tube, and a gas supply and exhaust of the intermediate room 10 are performed independent of the gas supply and exhaust of the first muffle tube and a furnace body room.

Abstract: A method for making sponge-effect knitted fabric using needles on the roll of a circular machine for hosiery or knitwear which uses a skipped needle knitted fabric making procedure to selectively work an elastic or stretch thread and a non-elastic thread together or the one separately from the other. A manufactured product is also obtained with one or more designed parts made up of sponge-effect fabric of piles or loops in relief formed by selectively working one or the other of the two starting threads.

Abstract: The invention provides an apparatus comprising a drum for containing and agitating an article, wherein the drum comprises at least two rotatable portions in rotatable connection with one another, a rotator member in connection with each rotatable portion for rotating the portion about an axis. The apparatus is preferably a washing machine, and the method of operating the apparatus comprises inserting at least one article, preferably a plurality of articles, into the drum; and rotating each rotatable portion independently of one another to agitate the article or articles.

Abstract: A lock is fitted with a locking element and a control element which is rotated by a drive to-and-fro in order to axially reciprocate the locking element through a coaxial drive element between a locked and an unlocked position. The drive element and the control element are also configured coaxially and cooperative by means of a cross-pin which is axially displaceable in a transverse borehole of the inner drive element and by means of two helical inner channels as well as an adjoining plane terminal surface of the outer control element which runs perpendicular to the axis of rotation of the control element and is bounded by a side ramp running from the bottom of one channel past the other channel on the outside thereof toward the drive element.

Abstract: A safety pin and magnetic key to actuate, loosen or tighten the pin, which incorporate means to automatically and by magnetic attraction connect a body of a cavity of a head of the pin, formed by a fixed part of a rod and by a movable part, by applying the key. The safety head of the pin delimits a totally closed cavity for a body of magnetic material, enabled to slide axially inside the cavity, provided with lateral locking means cooperating with means of the body, which is pressed against a bottom of the cavity by a spring supported by an upper base of the movable part, having external blind orifices for eyebolts of the key. The latter incorporates in a tubular body a permanent magnet on its extremity, with eyebolt support for insertion into the blind orifices and applying simultaneously a magnetic force through the support to the base of the movable part. This permits to attract the body of the cavity and to lock the parts of the head in order to apply an actuating torque on the pin.

Abstract: Disclosed is a method for enhancing fatigue strength of a gear by producing compressive residual stress on a gear surface using shot peening. In the method according to the present invention, a plurality of shot balls are projected in a direction parallel to a straight line connecting a contact point of a root circle and an involute curve of a gear tooth to be subjected to the peening to a contact point of a tooth face circle and an involute curve of a gear tooth adjacent to the gear tooth to be subjected to the peening, and particularly a direction forming an angle of 0° to 15° relative to the straight line by use of high-pressure air.

Abstract: An apparatus for producing annularly corrugated metal tubes, particularly the outer conductor of coaxial high-frequency cables, using at least one pressure roller revolving around a plain tube. The corrugations are formed in the plain tube by the teeth of the pressure roller, which is rotatable about an axis at a 90° angle to the longitudinal axis of the tube, and the axis of rotation of the pressure roller, itself in a plane perpendicular to the longitudinal axis of the tube, revolves around the plain tube being fed to the pressure roller as the corrugations are produced. The plain tube in turn rotates the pressure roller by its feed. The tips of the teeth are substantially flat, the tube is tightly guided in a guide bushing (12) in front of and behind the engagement with the pressure roller (13), and the number of teeth (Z) ranges between 7 and 11, preferably between 8 and 10.