Abstract: A rolling mill stand for rolling rod-shaped bodies, in particular tubular bodies, said stand comprising at least three rolls (10) mutually arranged to define a rolling pass line for said rod-shaped and/or tubular bodies, wherein at least one of said three rolls (10) is rigidly mounted on a roll holder shaft (20), freely fixed in turn in a rotational manner to said stand by means of a first hollow support (40) and a second hollow support (30) arranged on opposite sides of said at least one roll (10), respectively, wherein a first portion (21) and a second portion (22) of said roll holder shaft (20) are housed in said first hollow support (40) and in said second hollow support (30), respectively, where the constraint between at least said first hollow support and said first portion (21) of the roll holder shaft is of elastic type.

Abstract: A rolling mill stand for rolling rod-shaped bodies, in particular tubular bodies, said stand comprising at least three rolls (10) mutually arranged to define a rolling pass line for said rod-shaped and/or tubular bodies, wherein at least one of said three rolls (10) is rigidly mounted on a roll holder shaft (20), freely fixed in turn in a rotational manner to said stand by means of a first hollow support (40) and a second hollow support (30) arranged on opposite sides of said at least one roll (10), respectively, wherein a first portion (21) and a second portion (22) of said roll holder shaft (20) are housed in said first hollow support (40) and in said second hollow support (30), respectively, where the constraint between at least said first hollow support and said first portion (21) of the roll holder shaft is of elastic type.

Abstract: An integrated transverse rolling mill for rolling seamless tubes with skewed axes comprising a piercing stand (2) with skewed axis rolling rolls for piercing a first tube (7) having a first length which is shorter than the space which separates it from the subsequent finishing stand (3) in cooperation with the stake (6), which has the first piercing tip (20) at its end and the second finishing tip (21) at the finishing stand (3). The finishing stand (3) is arranged downstream of the piercing stand (2) so that during the rolling operations the front end of the first tube (7) may only be gripped by the finishing stand (3) once the rear end of the first tube (7) is no longer gripped by the rolling stand (2).

Abstract: The present invention relates to a multi-stand rolling mill (1) for tubular bodies. The rolling mill comprises a first section (10) for rolling on mandrel defined by a first plurality of rolling stands (15?, 15, 15?) arranged in sequence along a rolling axis (100). According to the invention, the rolling mill also comprises a second rolling section without mandrel, arranged down-stream of said first section, which comprises a second plurality of stands (25?, 25, 26, 27, 26?, 27?) arranged in sequence along said rolling axis (100). Each stand (25?, 25, 26, 27, 26?, 27?) of said second section (20) comprises three rollers having rotation axes which are arranged at 120° from one another. The rotation axes for each stand (25?, 25, 26, 27, 26?, 27?) are rotated by 180° with respect to corresponding rotation axes of an adjacent stand. According to the invention, at least one stand of said second section (20) comprises a motorized roller having a vertical rotation axis.

Abstract: A rolling plant (R) for rolling tubes having a multi-stand rolling mill (5) with two or more rolls, in order to implement a controlled speed mandrel rolling process, comprises a hooking and releasing device (61) which is arranged in the inlet area of the rolling mill (5) to cooperate with the rear tang of the mandrel (31) and a hooking and releasing device (71) which is arranged in the outlet area of the rolling mill (5) to cooperate with the front tang of the mandrel (31) in coordinated manner with the first hooking and releasing device (61).

Abstract: A rolling stand for tubes or rounds comprising two or more rolls defining a rolling section of the rolling stand that is coaxial to a rolling axis Y of the same stand, each roll having a respective rolling surface defining a respective straight line of symmetry passing through the rolling axis and through the center of symmetry of the respective surface, thus determining a first half and a second half of the respective surface. The rolling stand also including two gap zones having a radial distance from the rolling axis and a groove bottom zone having a radial distance from the rolling axis at the intersecting point of the respective surface with the respective straight line of symmetry, the rolling stand providing, for each roll on said respective rolling surface, at least one first pushing zone and at least one second pushing zone.

Abstract: A roll-holder cartridge for a three-tube rolling stand with means adapted to release a tube during rolling in case of emergency. The roll-holder cartridge (3) has on both side walls a substantially Y-shaped opening (10) laying with the foot at the vertical axis yoke support so as to be able to pull out the roll-holder cartridge according to a direction coinciding with the horizontal axis of the vertical axis yoke while leaving the support hanging from the fixed structure (13) of the rolling stand. In case of normal maintenance operation, the cartridge (3) is pulled out sideways from the structure of the rolling mill with the yoke support of the vertical axis roll anchored to the cartridge itself, like the other supports of the rolls.

Abstract: A method and a device for releasing a tube during a rolling process in a three-roll rolling stand in case of an emergency. The roll holder cartridge (3) has a longitudinal open slot (10) at the yoke support of the vertical axis roll so as to remove the roll holder cartridge according to a direction coinciding with the horizontal axis of the yoke support of the vertical axis roll while the support remains anchored to the fixed structure in the stand of the roll mill. In case of routine maintenance, the cartridge (3) is pulled out laterally with the yoke support of the vertical axis roll anchored to the cartridge itself as the other roll supports.

Abstract: The rolling stand comprises four support columns (2), two conical rolling rolls with skewed rolling axes which are oblique to each other and are fixed to two roll cradles (6, 7), four jacks (24, 26) below the lower roll cradle (7) for exercising a preloading force on such a roll cradle. Four jacks (20, 21, 22, 23) are arranged above to exercise a preloading force on the upper roll cradle (6) during rolling. The stand also comprises four upper hydraulic capsules (((30, 32, 33, 40, 42, 43) and four lower hydraulic capsules (37, 46), 47) for exercising push forces and controlling the upper (6) and lower (7) roll cradles and the rolling position of the working rolls.

Abstract: In order to facilitate side extraction of the roller holder cartridge (3) in a rolling mill stand (100), the strokes of the hydraulic capsules needed to take the pistons of the same clear from the trajectory traveled by the roller holder cartridge (3) during the extraction of the same from the rolling mill, may reach values indicatively between 150 and 400 mm, values which can negatively affect response times of the position control system of said capsules (4?). In order to continue to apply the same capsule control methods but with a considerably more dynamic system capable of rapidly and accurately reacting to sudden changes of pressure, the servo valves in the control circuits are of the four-way type, instead of the three-way type.

Abstract: A mandrel holder head with release/fastening device of the mandrel for rolling metallic tubes comprises a mandrel holder (1) which accommodates within an internal seat a half collar (2) of externally cylindrical shape through an opening in the side wall. In the internal seat are accommodated both an end part (52) of the mandrel shank and the half collar (2) through the opening. The half collar has an internal cavity with a second longitudinal side opening which accommodates a second part (51) of the shank of diameter smaller than that of the first part (52). The half collar is divided along an axial direction into two cylindrical parts (21, 22) which have different diameters. The locking member (30, 31) of the half collar (2) holds it in the mandrel holder (1) seat in working conditions, while allowing shank release with an axial movement in locked conditions.

Abstract: A tube rolling plant (R) with multi-stand rolling mill having two or more rollers, for implementing a mandrel rolling process with controlled speed has a mandrel (31) which is inserted into the hollow body (39) from the frontal opening thereof by passing it first through the rolling mill (5). An opposite movement (L3) with respect to the rolling direction is imparted to the mandrel (31) by way of the hooking device (61) when rolling the hollow body (39) and the rear end of the rolled tube (42) is extracted at the end of the rolling operation.

Abstract: A method and a device for releasing a tube during a rolling process in a three-roll rolling stand in case of an emergency. The roll holder cartridge (3) has a longitudinal open slot (10) at the yoke support of the vertical axis roll so as to remove the roll holder cartridge according to a direction coinciding with the horizontal axis of the yoke support of the vertical axis roll while the support remains anchored to the fixed structure in the stand of the roll mill. In case of routine maintenance, the cartridge (3) is pulled out laterally with the yoke support of the vertical axis roll anchored to the cartridge itself as the other roll supports.

Abstract: An integrated transverse rolling mill for rolling seamless tubes with skewed axes comprising a piercing stand (2) with skewed axis rolling rolls for piercing a first tube (7) having a first length which is shorter than the space which separates it from the subsequent finishing stand (3) in cooperation with the stake (6), which has the first piercing tip (20) at its end and the second finishing tip (21) at the finishing stand (3). The finishing stand (3) is arranged downstream of the piercing stand (2) so that during the rolling operations the front end of the first tube (7) may only be gripped by the finishing stand (3) once the rear end of the first tube (7) is no longer gripped by the rolling stand (2).

Abstract: A rolling plant (R) for rolling tubes having a multi-stand rolling mill (5) with two or more rolls, in order to implement a controlled speed mandrel rolling process, comprises a hooking and releasing device (61) which is arranged in the inlet area of the rolling mill (5) to cooperate with the rear tang of the mandrel (31) and a hooking and releasing device (71) which is arranged in the outlet area of the rolling mill (5) to cooperate with the front tang of the mandrel (31) in coordinated manner with the first hooking and releasing device (61).

Abstract: A rolling plant (R) for rolling tubes having a multi-stand rolling mill (5) with two or more rolls, in order to implement a controlled speed mandrel rolling process, comprises a hooking and releasing device (61) which is arranged in the inlet area of the rolling mill (5) to cooperate with the rear tang of the mandrel (31) and a hooking and releasing device (71) which is arranged in the outlet area of the rolling mill (5) to cooperate with the front tang of the mandrel (31) in coordinated manner with the first hooking and releasing device (61).

Abstract: A rolling mill stand and related rolling mill for rolling rod-shaped bodies, even large in size, which meets the requirement of stiffness uniformity of the rolling mill stands in the transversal direction, all the hydraulic capsules being firmly fixed to the external structure of the rolling mill and providing for the side change of the rolls of each stand. The arrangement of rolling rolls and related extensions of each rolling mill stand is such to avoid problems of corrosion and damaging to the extensions themselves and to the reducers due to the drainage of the cooling waters.

Abstract: A rolling stand (1) with three working rolls (5, 6, 7) defining a rolling axis (X) and comprising a roll-holding cartridge (2) in which said three working rolls (5, 6, 7) with respective chocks are accommodated; wherein a locking device (20) is provided for locking the position of the chocks within the roll-holding cartridge (2), in order to lock the chocks in a predetermined position before carrying out a lateral extraction of the roll-holding cartridge (2) from the rolling stand; wherein said locking device (20) is of the movable type and controlled by control means.

Abstract: A roll-holder cartridge for a three-tube rolling stand with means adapted to release a tube during rolling in case of emergency. The roll-holder cartridge (3) has on both side walls a substantially Y-shaped opening (10) laying with the foot at the vertical axis yoke support so as to be able to pull out the roll-holder cartridge according to a direction coinciding with the horizontal axis of the vertical axis yoke while leaving the support hanging from the fixed structure (13) of the rolling stand. In case of normal maintenance operation, the cartridge (3) is pulled out sideways from the structure of the rolling mill with the yoke support of the vertical axis roll anchored to the cartridge itself, like the other supports of the rolls.

Abstract: The rolling stand comprises four support columns (2), two conical rolling rolls with skewed rolling axes which are oblique to each other and are fixed to two roll cradles (6, 7), four jacks (24, 26) below the lower roll cradle (7) for exercising a preloading force on such a roll cradle. Four jacks (20, 21, 22, 23) are arranged above to exercise a preloading force on the upper roll cradle (6) during rolling. The stand also comprises four upper hydraulic capsules (((30, 32, 33, 40, 42, 43) and four lower hydraulic capsules (37, 46), 47) for exercising push forces and controlling the upper (6) and lower (7) roll cradles and the rolling position of the working rolls.