Abstract: In a microwave irradiation apparatus, an applicator portion has an interior space for housing an object to be irradiated. A first microwave irradiation system outputs a first microwave to the interior space in a first mode so as to generate a large electric field and a small magnetic field at a specific place of the interior space. A second microwave irradiation system outputs a second microwave having a polarization plane crossing a polarization plane of the first microwave to the interior space in a second mode so as to generate a large magnetic field and small electric field at the specific place of the interior space.

Abstract: A microwave irradiation system includes first and second microwave generators, and an applicator which includes: a microwave transmission part connected to the first and second microwave generators; a reflecting plane, at an other end of the microwave transmission part of the applicator, configured to reflect microwaves from the first and the second microwave generators at such a location that a space of an object, in the microwave transmission part of the applicator between the end and the other end is irradiated with both a greater intensity of electric field and a smaller intensity of magnetic field generated by the first microwave generator and with both a greater intensity of magnetic field and a smaller intensity of electric field generated by the second microwave generator; and a filter part through which at least one of the first and second microwave generators is connected to the applicator.

Abstract: PROBLEM TO BE SOLVED: To provide a microwave heating device evenly and efficiently irradiating a heating object with microwaves without using a turning mechanism. SOLUTION: In an applicator 8, a heating object 12 such as a food is placed on an upper surface of a metal table 11 in a minimum capacity. A conically cut fluororesin spacer 13 is disposed above the heating object 12. A microwave synthesized in a T-shaped waveguide 7 is radiated to the heating object 12 through the conically cut fluororesin spacer 13. Thus, the synthesized microwave transmitted from the T-shaped waveguide 7 and having electric field difference of 90 degrees is refracted by a wavelength shortening action of the fluororesin spacer 13, and is evenly radiated to an area of the heating object 12 in a concentrated manner. Accordingly, the heating object 12 can be evenly and efficiently heated without providing a turntable.

Abstract: In a tube expanding apparatus of a damper tube supporting a thrust force of a punch applied to the damper tube by a stopper at a time of retaining one end of the damper tube by the stopper, inserting the other end of the damper tube to a die, inserting the punch to the other end of the damper tube so as to propel, and expand the other end of the damper tube while carrying out an ironing operation, the apparatus is provided with a stopper releasing means for releasing the stopper at a time when a load in an axial direction applied to the damper tube due to an elongation by the ironing work of the damper tube increases over a critical load which is previously determined to be a smaller load than an expected buckling load in the damper tube.

Abstract: A microwave irradiation system includes first and second microwave generators, and an applicator which includes: a microwave transmission part connected to the first and second microwave generators; a reflecting plane, at an other end of the microwave transmission part of the applicator, configured to reflect microwaves from the first and the second microwave generators at such a location that a space of an object, in the microwave transmission part of the applicator between the end and the other end is irradiated with both a greater intensity of electric field and a smaller intensity of magnetic field generated by the first microwave generator and with both a greater intensity of magnetic field and a smaller intensity of electric field generated by the second microwave generator; and a filter part through which at least one of the first and second microwave generators is connected to the applicator.

Abstract: In a tube expanding apparatus of a damper tube supporting a thrust force of a punch applied to the damper tube by a stopper at a time of retaining one end of the damper tube by the stopper, inserting the other end of the damper tube to a die, inserting the punch to the other end of the damper tube so as to propel, and expand the other end of the damper tube while carrying out an ironing operation, the apparatus is provided with a stopper releasing means for releasing the stopper at a time when a load in an axial direction applied to the damper tube due to an elongation by the ironing work of the damper tube increases over a critical load which is previously determined to be a smaller load than an expected buckling load in the damper tube.

Abstract: In a microwave irradiation apparatus, an applicator portion has an interior space for housing an object to be irradiated. A first microwave irradiation system outputs a first microwave to the interior space in a first mode so as to generate a large electric field and a small magnetic field at a specific place of the interior space. A second microwave irradiation system outputs a second microwave having a polarization plane crossing a polarization plane of the first microwave to the interior space in a second mode so as to generate a large magnetic field and small electric field at the specific place of the interior space.

Abstract: A microwave heating unit has a construction to supply a microwave generated by a magnetron to a microwave irradiation chamber having a cylinder in which a container is stored and to irradiate the microwave supplied to the microwave irradiation chamber to a part of a container so that a convection flow is generated in a liquid in the container. By this construction, without requiring a complicated construction for uniform irradiation on the whole surface of the container, uniform heating on the entire liquid stored in the container is made possible with a simplified construction for irradiation of a microwave.

Abstract: A magnetron has an anode cylinder, a plurality of vanes extending radially inwardly from the anode cylinder, a cathode filament extending along a center axis of the anode cylinder, an output section including an antenna coupled to one of the vanes, and a magnetic circuit section for supplying a magnetic field into the anode cylinder, whereby the magnetron oscillates at a fundamental frequency in a range from 400 MHz to 600 MHz.

Abstract: A magnetron has an anode cylinder, a plurality of vanes extending radially inwardly from the anode cylinder, a cathode filament extending along a center axis of the anode cylinder, an output section including an antenna coupled to one of the vanes, and a magnetic circuit section for supplying a magnetic field into the anode cylinder, whereby the magnetron oscillates at a fundamental frequency in a range from 400 MHz to 600 MHz.

Abstract: A magnetron includes a cathode mount having a directly heated helical cathode filament for emitting thermoelectrons, an upper end shield and a lower end shield disposed so as to support the filament at upper and lower ends thereof, and center and side leads holding the upper and lower end shields respectively. The lower end shield is formed with a recess for housing the lower end of the directly heated helical cathode filament in the upper surface thereof, at least a portion of the inner wall of the recess is sloped, and a groove is formed at the peripheral edge of the bottom of the recess.

Abstract: A magnetron having eight anode vanes (2) arranged radially inside an anode cylinder (3) and a helically coiled, directly heated filament positioned along the anode cylinder. The magnetron oscillates at a basic frequency of 2450 MHz. The external diameter of the helically coiled, directly heated filament is in the range of 2.6 to 3.2 mm, and the diameter between the internal ends of the anode vanes is in the range of 7.0 to 8.0 mm.

Abstract: A magnetron preventing increases of dark current by making an axial static magnetic field on a plane containing an inner surface of an end shield on the microwave output port side in the interaction space different from the static magnetic field on a plane containing an inner surface of the end shield on the cathode stem side. The interaction-space-side axial end of a peripheral portion of the end shield associated with the weaker static magnetic field is displaced a predetermined distance axially toward the interaction space from the axial ends of the magnetron vanes. In one embodiment, the axial static magnetic field on a plane containing an inner surface of the end shield on the microwave output port side in the interaction space is made stronger than the static magnetic field on a plane containing an inner surface of the end shield on the cathode stem side. This compensates for eccentricity of the axis of the cathode with respect to the axis of the anode vanes.

Abstract: A magnetron provided with a filter circuit for suppressing leaking of the electromagnetic wave of the magnetron. First and second choke coils have their respective first ends serially connected to two externally protruding leads for supporting a cathode filament of the magnetron. A feed-through capacitor is parallelly connected to the second ends of the first and second choke coils respectively. The feed-through capacitor is constituted by a dielectric ceramic material having a relative dielectric constant .epsilon..sub.s which satisfies .sqroot..epsilon..sub.s .ltoreq.50, whereby sound pressure produced by of the feed-through capacitor is reduced without increasing the size of the feed-through capacitor and while keeping the necessary breakdown voltage characteristic and necessary electrostatic capacity.

Abstract: There is disclosed a magnetron whose oscillation frequency can be easily adjusted. The magnetron comprises a cylindrical anode, several anode vanes radially arranged around the axis of the anode, and two strap rings of the same structure. Alternate ones of the anode vanes are connected together by one of the strap rings. The remaining anode rings are connected together by the other strap ring. The two strap rings are displaced circumferentially relative to each other by a given angle centering around the axis of the anode.

Abstract: In a magnetron of the type wherein magnetic flux of opposing permanent magnets is passed axially through an interaction space by way of pole pieces attached to opposing surfaces of the permanent magnets, at least one pole piece on the output side is constructed to contact the output side permanent magnet through annular contact surface.