A rolling mill includes three or more rolling rolls aligned along a circumferential direction and arranged so each rotary shaft is skewed with respect to a pass line of a material to be rolled, wherein the material to be rolled made of a pipe or bar material passes between the rolling rolls while being rotated to undergo diameter reducing rolling. At least one rolling roll selected from the three or more rolling rolls is smaller in roll diameter than at least one other rolling roll. When at least one rolling roll having a relatively maximum roll diameter defined as a maximum diameter rolling roll and at least one rolling roll smaller in roll diameter than the maximum is defined as a small diameter rolling roll, the small diameter rolling roll has a roll diameter equal to or less than 90% of the roll diameter of the maximum diameter rolling roll.

A hand-powered jewellery rolling mill is disclosed. The mill comprises a support frame and a pair of opposed parallel cylindrical rollers rotatably mounted to the support frame. A drive shaft is connected to at least one of the rollers for rotation thereof. A manually rotatable handle is configured for providing a drive force to the drive shaft. The handle may be connected to the drive shaft through a high-ratio gear train. The rolling mill may further comprise an input shaft, rotatable by the manually rotatable handle. The input shaft may have a worm and a worm-to-gear coupling may transfer torque from the input shaft to the drive shaft.

A hand-powered jewellery rolling mill is disclosed. The mill comprises a support frame and a pair of opposed parallel cylindrical rollers rotatably mounted to the support frame. A drive shaft is connected to at least one of the rollers for rotation thereof. A manually rotatable handle is configured for providing a drive force to the drive shaft. The handle may be connected to the drive shaft through a high-ratio gear train. The rolling mill may further comprise an input shaft, rotatable by the manually rotatable handle. The input shaft may have a worm and a worm-to-gear coupling may transfer torque from the input shaft to the drive shaft.

A power transmission device includes a first power transmission path for transmitting a driving force of a motor to one driven shaft, and a second power transmission path for transmitting the driving force of the motor to another driven shaft. At least one of the first power transmission path or the second power transmission path includes a first intermediate rotor fixed to an output shaft of the motor, a second intermediate rotor rotated by the first intermediate rotor and moving arcuately along an outer circumference of the first intermediate rotor, a driving shaft rotated by the second intermediate rotor and transmitting the driving force to the one driven shaft or the another driven shaft. The driving shaft is configured to move in a direction perpendicular to an axial center direction of the driving shaft in accordance with movement of the second intermediate rotor around the first intermediate rotor.

A plate and strip rolling process oriented efficient and stable current applying manipulator is provided, which aims to effectively avoid potential safety hazards caused integral electrifying of the rack during normal current applying, can improve the defects that current loss is caused by a normal current applying way and the service life of the roller is shortened, and the difficulty in applying pulse current to plate strips while rolling plate strips with limited length dimensions at a higher temperature, and can realize stable loading of pulse current with limited dimension, and effectively act pulse current within a rolling region.

A plate and strip rolling process oriented efficient and stable current applying manipulator is provided, which aims to effectively avoid potential safety hazards caused integral electrifying of the rack during normal current applying, can improve the defects that current loss is caused by a normal current applying way and the service life of the roller is shortened, and the difficulty in applying pulse current to plate strips while rolling plate strips with limited length dimensions at a higher temperature, and can realize stable loading of pulse current with limited dimension, and effectively act pulse current within a rolling region.

A rolling mill system for Incremental rotary shaping of an elongated workpiece is provided that includes first and second workpiece holders. A support frame has a track with the first and second workpiece holders being movably associated with the track, the workpiece holders and an associated workpiece being movable in unison along the track. A radial chuck is mounted to the frame that includes a plurality of jaws that are movable radially inwardly and outwardly. Each jaw has a tool mounted thereto that is rotatable about an axis of rotation, with the axis of rotation of each tool being oriented at a skew angle relative to the longitudinal axis of a workpiece. A source of electric current and an electrically conductive flow path are provided for flowing electrical current through a workpiece. A controller is provided that is configured to control the operation of each of the first motor, second motor and third motor, and to control the flow of current flowing through the tools to the workpiece.

A rolling mill system for Incremental rotary shaping of an elongated workpiece is provided that includes first and second workpiece holders. A support frame has a track with the first and second workpiece holders being movably associated with the track, the workpiece holders and an associated workpiece being movable in unison along the track. A radial chuck is mounted to the frame that includes a plurality of jaws that are movable radially inwardly and outwardly. Each jaw has a tool mounted thereto that is rotatable about an axis of rotation, with the axis of rotation of each tool being oriented at a skew angle relative to the longitudinal axis of a workpiece. A source of electric current and an electrically conductive flow path are provided for flowing electrical current through a workpiece. A controller is provided that is configured to control the operation of each of the first motor, second motor and third motor, and to control the flow of current flowing through the tools to the workpiece.

A power transmission device includes a first power transmission path for transmitting a driving force of a motor to one driven shaft, and a second power transmission path for transmitting the driving force of the motor to another driven shaft. At least one of the first power transmission path or the second power transmission path includes a first intermediate rotor fixed to an output shaft of the motor, a second intermediate rotor rotated by the first intermediate rotor and moving arcuately along an outer circumference of the first intermediate rotor, a driving shaft rotated by the second intermediate rotor and transmitting the driving force to the one driven shaft or the another driven shaft. The driving shaft is configured to move in a direction perpendicular to an axial center direction of the driving shaft in accordance with movement of the second intermediate rotor around the first intermediate rotor.

A rolling mill system for Incremental rotary shaping of an elongated workpiece is provided that includes first and second workpiece holders. A support frame has a track with the first and second workpiece holders being movably associated with the track, the workpiece holders and an associated workpiece being movable in unison along the track. A radial chuck is mounted to the frame that includes a plurality of jaws that are movable radially inwardly and outwardly. Each jaw has a tool mounted thereto that is rotatable about an axis of rotation, with the axis of rotation of each tool being oriented at a skew angle relative to the longitudinal axis of a workpiece. A source of electric current and an electrically conductive flow path are provided for flowing electrical current through a workpiece. A controller is provided that is configured to control the operation of each of the first motor, second motor and third motor, and to control the flow of current flowing through the tools to the workpiece.