Abstract: An antenna device includes: a first antenna having a directional gain at a low elevation angle higher than the directional gain at a high elevation angle; a second antenna having the directional gain at the high elevation angle higher than the first antenna, transmitting and receiving a radio wave having a vibration direction of an electric field intersecting with a radio wave transmitted and received by the first antenna; and a third antenna having the directional gain at the high elevation angle higher than the first antenna, and transmitting and receiving a radio wave having a vibration direction of an electric field intersecting with the radio wave transmitted and received by the second antenna.

Abstract: A continuous casting method and apparatus therefor wherein a reaction force/reduction controller selects a pivot reduction roll such that the thickness of the solidified shell of the cast slab having a liquid core is equal to the target thickness T.sub.ref, and calculates a difference between a thickness T.sub.in of the cast slab having a liquid core at the inlet of the reduction roll zone PRT and the target thickness T.sub.ref, i.e., .DELTA.T. The resulting value of .DELTA.T, i.e., a target reduction is provided to the reduction controllers 2 of the pivot reduction roll. The reaction force/reduction controller 1 assigns target reductions 1/3 .DELTA.T and 2/3 .DELTA.T to the two reduction rolls upstream of the pivot reduction roll. The reaction force/reduction controller 1 calculates a target pressure (P.sub.i +.alpha.) on the basis of the selected value for .alpha., and the resulting target pressure (P.sub.i +.alpha.

Abstract: In a slab continuous casting machine comprising a tundish for reserving a molten steel therein, a nozzle holding cassette disposed on an outer bottom portion of the tundish, a mold for use in a casting, and an immersing nozzle mounted in the nozzle holding cassette and for pouring the molten steel in the tundish into the mold, the cavity has a generally rectangular sectional shape defined by a pair of short sides and a pair of long sides. When the immersing nozzle is inserted into the mold and when the immersing nozzle is taken out from the mold, a movement of the immersing nozzle gripped by a handling arm in the mold is limited in a direction parallel to the pair of short sides.

Abstract: A thin slab that is free of internal cracks is formed by reducing a continuously cast strand having a liquid core. The placement of the reduction rolls is controlled to effect a suitable amount of reduction. The methods effectively reduce bulging strain, as well as strain associated with reduction of the strand. As a result, total accumulated strain is reduced and a thin slab free of internal cracks can be manufactured at high speeds. The apparatus includes reduction blocks which are capable of shifting the rotation angle of an upper roller segment frame. Misalignment strain is reduced and the thickness of the strand can be changed without stopping the manufacturing operation.

Abstract: An endless track continuous casting machine having a pair of upper and lower endless belts facing each other in a spaced apart relationship and travelling in a downwardly slanted direction which form the long side walls of a mold. Dam blocks continuously and closely disposed and pinched between both side edges of the pair of endless belts and each supported by a link forming part of an endless chain wound around sprockets disposed on each side of the pair of endless belts form the short side walls of the mold. The dam blocks are mounted on each of the links of the endless chain to be movable inwardly and outwardly, and they are guided by a guiding mechanism to a projecting position when entering the advancing path of the mold and are guided to a set back position when entering the returning route. This guiding mechanism is adjustable to change the projected position of each dam block while the endless chain is moving, thus enabling the width of a cast piece to be altered without stopping the casting work.

Abstract: Herein disclosed is a loop type continuous metal casting machine in which two side dams are revolved in a loop passing along a casting zone from the entrance end thereof between upper and lower endless revolving casting belts to define a downhill moving mold and in which each of the side dams is formed of a multiplicity of metal dam blocks so strung onto a flexible metal strap loop that the metal dam blocks abut in end-to-end relationship against one another but are allowed to slide on and relative to the metal strap loop.