Abstract: In a roll changing apparatus of a rolling mill, a stationary roll changing table is provided on a front surface of a work side of the rolling mill. Pull-out rails and upwardly and downwardly movable shift rails are provided on the roll changing table. Shift blocks are provided for detachably attaching to a work roll assembly which has been pulled out, to move the work roll assembly sideways in a shifting direction. Only the work roll assembly to be pulled out can be shifted easily, and replaced with a new work roll assembly without the use of an elaborate foundation structure. Thus, work rolls can be changed swiftly.

Abstract: A continuous hot rolling mill with a metal block conveying apparatus and a metal block joining apparatus which moves with the metal blocks along the metal block conveying apparatus to conform a joining operation. The metal block conveying apparatus uses rollers supported by cylinders with a common hydraulic circuit which allows the cylinders to follow guide rails on the metal block joining apparatus and lower out of the path of the metal block joining apparatus and then return to a metal block support position after the metal block joining apparatus' passage without individual control circuits and valves for each of the cylinders.

Abstract: The invention comprises a continuous hot rolling method in which a rear end portion of a preceding metal block and a fore end portion of a succeeding metal block are cut and the metal blocks are joined to each other by heating and pressing followed by a finish rolling. A region of each metal block is restrained from a clamping position to the end portion thereof in order to prevent a change in level of the metal blocks in heating and pressing the piece. The end portions of the metal blocks can be thus prevented from deformation.

Abstract: According to the invention, the rear end of a preceding metal piece and a front end of a succeeding metal piece are heated, pressed and joined prior to the finishing hot rolling. An alternating magnetic field running through the metal pieces in the thickness direction thereof is generated in an end region on opposed faces of the respective metal pieces to perform heating. Another alternating magnetic field whose direction is reverse with respect to that of the former alternating magnetic field is partially generated in the end region on the opposed faces of the metal pieces and in either a region where the metal pieces exist or a region outside width ends of the metal pieces. This assures a uniform heating of the end region on the opposed faces of the metal pieces over their full width to reliably join the both metal pieces to each other.

Abstract: A method and apparatus for joining metal pieces wherein the rear end of a preceding metal piece and a front end of a metal piece are heated and then pressed together prior to hot finished rolling. The temperature the ends of the metal pieces are heated to is a temperature range between the solidus and liquidus line temperatures of the metal(s) to be joined.

Abstract: According to the invention, the rear end of a preceding metal piece and a front end of a succeeding metal piece are heated, pressed and joined prior to the finishing hot rolling. An alternating magnetic field running through the metal pieces in the thickness direction thereof is generated in an end region on opposed faces of the respective metal pieces to perform heating. Another alternating magnetic field whose direction is reverse with respect to that of the former alternating magnetic field is partially generated in the end region on the opposed faces of the metal pieces and in either a region where the metal pieces exist or a region outside width ends of the metal pieces. This assures a uniform heating of the end region on the opposed faces of the metal pieces over their full width to reliably join the both metal pieces to each other.

Abstract: Method and apparatus for joining metal pieces using induction heating. Metal pieces to be joined are placed end-to-end with a gap between them and induction heated in the thickness portion. To maximize speed and even heating edge-to-edge of the ends, members of a magnetic substance are provided in a gap between the inductor and the piece to be heated, thereby enhancing local heating effect by increasing magnetic flux density. Once heated, the ends are pressed together end-to-end for joining.

Abstract: An apparatus for joining metal pieces using induction heating. Preceding and succeeding metal pieces are followed by a carriage which carries an inductor. The inductor has the ability to move in the longitudinal direction of the metal pieces relative to the carriage to allow the inductor to move more or less upon the preceding or succeeding metal pieces to increase or decrease the induction heating effect, thereby taking into account any thickness variation of the metal pieces and yet still heating them evenly with regard to each other, prior to their being pressed against each other for joining before hot finishing rolling.

Abstract: The invention comprises a continuous hot rolling method in which a rear end portion of a preceding metal block and a fore end portion of a succeeding metal block are cut and the metal blocks are joined to each other by heng and pressing followed by a finish rolling. A region of each metal block is restrained from a clamping position to the end portion thereof in order to prevent a change in level of the metal blocks in heating and pressing the piece. The end portions of the metal blocks can be thus prevented from deformation.

Abstract: A post continuous hot rolling method where a rear end portion of a preced metal block and a fore end portion of a succeeding metal block are cut and the metal blocks joined to each other by heating and pressing followed by a finish rolling, wherein a poorly joined portion is removed by shaving the defective portion through application of rotating cutters prior to a final finish rolling of the joined blocks.

Abstract: According to the invention, the rear end of a preceding metal piece and a front end of a succeeding metal piece are heated, pressed and joined prior to the finishing hot rolling. An alternating magnetic field running through the metal pieces in the thickness direction thereof is generated in an end region on opposed faces of the respective metal pieces to perform heating. Another alternating magnetic field whose direction is reverse with respect to that of the former alternating magnetic field is partially generated in the end region on the opposed faces of the metal pieces and in either a region where the metal pieces exist or a region outside width ends of the metal pieces. This assures a uniform heating of the end region on the opposed faces of the metal pieces over their full width to reliably join the both metal pieces to each other.

Abstract: The invention comprises a continuous hot rolling method in which a rear end portion of a preceding metal block and a fore end portion of a succeeding metal block are cut and the metal blocks are joined to each other by heating and pressing followed by a finish rolling. A region of each metal block is restrained from a clamping position to the end portion thereof in order to prevent a change in level of the metal blocks in heating and pressing the piece. The end portions of the metal blocks can be thus prevented from deformation.

Abstract: A cross-rolling mill has upper and lower work rolls which can be made to cross one another together with their respective backup rolls by moving upper and lower roll chocks in pass lines opposite to each other with upper and lower cross heads. Upper and lower gradient portions are formed at opposite inclinations at side faces of the upper cross head and the lower cross head, respectively. Wedges having upper and lower oppositely inclined surfaces slidably engage the gradient portions of the upper and lower cross heads. The upper and lower cross heads can thus be moved in opposite pass line direction by moving the inclined surfaces of the wedges upward and downward.

Abstract: A rolling method and machine provides for decreasing the rolling load of work rolls of a rolling mill for a given reduction ratio achieved thereby. A pair of pinch rolls upstream of the work rolls have projections that form a large number of recesses in one or both surfaces of a metal workpiece. A lubricating agent is forced into the recesses in the region of contact between the workpiece and the work rolls. As a result, when the workpiece is rolled by the work rolls the lubricating agent is retained in the recesses such that the recesses progressively are flattened, thereby causing the lubricating agent to form a boundary film between the portion of the workpiece being rolled and the work rolls. The recesses are controlled to regulate the dimension of the length of each recess in the direction of rolling of the workpiece, to regulate the inclination of front and rear walls of each recess, and to regulate the total area of the recesses relative to the total surface area of the workpiece.

Abstract: A double action die set for closed forging to be equipped in a reciprocating press consisting of a stationary base and a slide. Each die is equipped with one set of a metal mold and a punch. A stationary side die is fixedly secured to the stationary base, while a movable side die is fixedly secured to the slide. Each one of the stationary side die and the movable side die comprises therein a metal mold supporting outer piston of hollow shape, a punch supporting inner piston slidably engaged with a hollow space in the outer piston, and a common oil chamber for supporting the outer piston and the inner piston with a same hydraulic pressure.According to this invention such advantages as to reduce the height of the die set and to move the pressurized oil only within the same oil chambers can be obtained.

Abstract: The known belt type continuous casting machine is improved in that a pair of guides for side dam block groups are disposed at opposite sides, in the widthwise direction, of a cast piece. Each of the guides includes guide beams disposed in two parallel rows displaced in direction of the thickness of the cast piece. Each of a pair of side dams which are movable in synchronism with feeding of the cast piece is formed of a side dam block group in one row. Each of the side dam block groups is divided into two sub-groups, each of which has a length longer than a contact length between the side dam block group and the cast piece and each of which is guided by a separate guide beam.

Abstract: An improved method and apparatus for grinding a rotary body, in which a rotatably supported grindstone is positioned in such manner that an extension of a rotary axis of the grindstone does not intersect a rotary axis of the rotary body and the rotary axis of the grindstone is inclined with respect to a plane perpendicular to the rotary axis of the rotary body to be ground. The rotary body to be ground is rotatably driven, and the grindstone is pressed against the outer circumferential surface of the rotary body to be ground in order that the outer circumferential surface of the rotary body to be ground can be ground by a relative slip produced at a contact point between the outer circumferential surface of the rotary body to be ground and the grindstone.