Abstract: An induction heating device for a metal strip, including: an induction coil provided on one side or on both sides of a front face side or a reverse face side of a metal strip, and that induces an induction current in the strip when a primary current is passed through the coil, the induction current configuring a closed loop as viewed from a direction perpendicular to a metal strip face; plural magnetic cores disposed at a specific position, this being a position at a back face side of the coil and separated from the strip by a specific distance, to concentrate magnetic flux generated by the coil in the strip; and a moving mechanism coupled to the magnetic cores, and that moves the cores to increase or decrease a disposed number of the cores at the specific position disposed side-by-side along a metal strip width direction.

Abstract: An induction heating device for a metal strip, including: an induction coil provided on one side or on both sides of a front face side or a reverse face side of a metal strip, and that induces an induction current in the strip when a primary current is passed through the coil, the induction current configuring a closed loop as viewed from a direction perpendicular to a metal strip face; plural magnetic cores disposed at a specific position, this being a position at a back face side of the coil and separated from the strip by a specific distance, to concentrate magnetic flux generated by the coil in the strip; and a moving mechanism coupled to the magnetic cores, and that moves the cores to increase or decrease a disposed number of the cores at the specific position disposed side-by-side along a metal strip width direction.

Abstract: The apparatus for cooling a hot-rolled steel sheet of the invention includes a thermometer that measures the temperature of the hot-rolled steel sheet; a shape meter that measures a shape of the hot-rolled steel sheet; a top side cooling device that cools a top surface of the hot-rolled steel sheet in a cooling section; a bottom side cooling device that cools a bottom surface of the hot-rolled steel sheet in the cooling section; and a control device that controls at least one of an amount of heat dissipated from the top surface by cooling and an amount of heat dissipated from the bottom surface by cooling of the hot-rolled steel sheet in the cooling section by controlling the top side cooling device and the bottom side cooling device based on temperature measurement results and shape measurement results.

Abstract: A method for manufacturing a steel sheet of the invention includes a hot-rolling process in which a steel material is hot-rolled using a finishing mill so as to obtain a hot-rolled steel sheet; and a cooling process in which the hot-rolled steel sheet is cooled. The hot-rolling process includes a target steepness-setting process in which a target steepness of the edge wave shape is set based on first correlation data indicating a correlation between a steepness of the edge wave shape of the hot-rolled steel sheet and a temperature standard deviation Y; and a shape-controlling process in which operation parameters of the finishing mill are controlled so as to match the steepness of the edge wave shape with the target steepness.

Abstract: The method for cooling a hot-rolled steel sheet of the invention includes a target ratio-setting process in which a top and bottom heat transfer coefficient ratio X1, at which a temperature standard deviation Y becomes a minimum value Ymin, is set as a target ratio Xt based on correlation data between a top and bottom heat transfer coefficient ratio X of the hot-rolled steel sheet and the temperature standard deviation Y of the hot-rolled steel sheet; and a cooling control process in which at least one of an amount of heat dissipated from a top surface by cooling and an amount of heat dissipated from a bottom surface by cooling of the hot-rolled steel sheet in the cooling section is controlled so that the top and bottom heat transfer coefficient ratio X of the hot-rolled steel sheet in the cooling section matches the target ratio Xt.

Abstract: The method for cooling a hot-rolled steel sheet of the invention includes a target ratio-setting process in which a top and bottom heat transfer coefficient ratio X1, at which a temperature standard deviation Y becomes a minimum value Ymin, is set as a target ratio Xt based on correlation data between a top and bottom heat transfer coefficient ratio X of the hot-rolled steel sheet and the temperature standard deviation Y of the hot-rolled steel sheet; and a cooling control process in which at least one of an amount of heat dissipated from a top surface by cooling and an amount of heat dissipated from a bottom surface by cooling of the hot-rolled steel sheet in the cooling section is controlled so that the top and bottom heat transfer coefficient ratio X of the hot-rolled steel sheet in the cooling section matches the target ratio Xt.

Abstract: The apparatus for cooling a hot-rolled steel sheet of the invention includes a thermometer that measures the temperature of the hot-rolled steel sheet; a shape meter that measures a shape of the hot-rolled steel sheet; a top side cooling device that cools a top surface of the hot-rolled steel sheet in a cooling section; a bottom side cooling device that cools a bottom surface of the hot-rolled steel sheet in the cooling section; and a control device that controls at least one of an amount of heat dissipated from the top surface by cooling and an amount of heat dissipated from the bottom surface by cooling of the hot-rolled steel sheet in the cooling section by controlling the top side cooling device and the bottom side cooling device based on temperature measurement results and shape measurement results.

Abstract: Hot dip galvanized steel sheet excellent in shapeability and plateability comprised of high strength steel sheet according to the present invention can be provided containing, by mass % about, C: 0.05 to 0.25%, Si: 0.3 to 2.5%, Mn: 1.5 to 2.8%, P: 0.03% or less, S: 0.02% or less, Al: 0.005 to 0.5%, N: 0.0060% or less and the balance of Fe and unavoidable impurities. The exemplary steel sheet can have thereon a galvanized layer containing, e.g., about Al: 0.05 to 10 mass % and Fe: 0.05 to 3 mass % and the balance of Zn and unavoidable impurities. Such exemplary hot dip galvanized steel sheet can have oxides containing Si in an average content of about 0.6 to 10 mass % at the crystal grain boundaries and in the crystal grains at the sheet steel side 5 ?m or less from the interface between the high strength steel sheet and the plating layer and by the presence of Fe—Zn alloy with an average grain size of about 0.5 to 3 ?m at the plating side.

Abstract: Hot dip galvanized steel sheet excellent in shapeability and plateability comprised of high strength steel sheet according to the present invention can be provided containing, by mass % about, C: 0.05 to 0.25%, Si: 0.3 to 2.5%, Mn: 1.5 to 2.8%, P: 0.03% or less, S: 0.02% or less, Al: 0.005 to 0.5%, N: 0.0060% or less and the balance of Fe and unavoidable impurities. The exemplary steel sheet can have thereon a galvanized layer containing, e.g., about Al: 0.05 to 10 mass % and Fe: 0.05 to 3 mass % and the balance of Zn and unavoidable impurities. Such exemplary hot dip galvanized steel sheet can have oxides containing Si in an average content of about 0.6 to 10 mass % at the crystal grain boundaries and in the crystal grains at the sheet steel side 5 ?m or less from the interface between the high strength steel sheet and the plating layer and by the presence of Fe—Zn alloy with an average grain size of about 0.5 to 3 ?m at the plating side.

Abstract: An rectangularly shaped illumination area utilizing an LED device having a high utilization efficiency in light flux and having an economical manufacturing cost is attained. Herein a light flux emitted from an LED chip 1 and then reflected by reflective surfaces of a horn 11 toward a lens 12 is concentrated into corner FIGS. 14 located in diagonal directions of the rectangular shape 4 while another light flux emitted from the LED chip 1 and directly incident to the lens 12 is focused by the lens on an area having an elliptic FIG. 13, which is inscribed in the rectangle area 4.

Abstract: There is disclosed a magnetic recording medium wherein a magnetic powder is uniformly dispersed in a curable substance of a binder resin material comprising a vinyl chloride-vinyl acetate series resin and/or a polyurethane series resin, at least one of which having a B value in a following apparent viscosity equation:log .eta.a=Bx+log [.eta.]wherein .eta.a is an apparent viscosity (cP) at a temperature of 25.degree. C., x is a resin concentration (wt %(), [.eta.] is a limiting viscosity (cP) at a temperature of 25.degree. C. and B is a constant, of 10 or less, which is measured by dissolving the resin in a mixed solvent of equal weights of methyl ethyl ketone toluene and cyclohexanone; and the B value of the mixed binder resin being 11 or less.The magnetic recording medium of the present invention is the high density recording medium having the great rectangular ratio and excellent in the noise properties.

Abstract: There is disclosed a method of controlling the level of a self-levelling device comprising a table to be controlled in level, an air spring supporting the table, a sensor for contactless detection of an amount of displacement of the table from a reference position, an inlet valve for supplying air under pressure to the air spring through an inlet port therein, and an outlet valve for discharging air from the air spring through an outlet port therein. An interval of time for actuating the inlet valve and/or the outlet valve to return the table to the reference position is computed from the amount by which the table is displaced. The inlet and/or outlet valve is then actuated for the calculated interval of time to adjust the table level through the air spring.

Abstract: A typewriter driven by an electric motor and provided with a ribbon vibrator for moving an erase ribbon in place of an ordinary printing ribbon as an occasional substitution from original position to printing position according to operation of a printing device for common use to both to erase a mistyped character. The ribbon vibrator is normally retained in non-operative status by a retaining member, which is moved in response to depression of a correction key to a predetermined evacuation position to allow the ribbon vibrator to operate and locked there by a lock member. The lock member is associated with not only a release key but also a manual switch member for controlling power supply to the electric motor. The engagement between the lock member and the retaining member is released in response to a turning operation of the manual switch member to OFF position for automatically restoring the ribbon vibrator to the non-operative status.

Abstract: A typewriter with a character erasing apparatus capable of consecutively erasing a series of characters as well as a single character once printed on a sheet of printing paper. The typewriter is provided with a retaining crank movable to first, second and third positions. In the first position the retaining crank retains a ribbon vibrator supporting an erase ribbon in non-operative status. In the second position the retaining crank permits the ribbon vibrator to operate while interrupting transmission of power for moving a platen. The retaining crank is automatically restored to the first position in response to return movement of the ribbon vibrator after the single character erasing. The retaining crank is moved to and held at the third position by a manual member for permitting the ribbon vibrator to operate consecutively. The retaining member does not interrupt the transmission of the power for moving the platen.