The invention relates to a shiftable transmission (1) having at least two shifting levels, preferably for use in rolling mill technology, said shiftable transmission comprising: a rotatably mounted input shaft (20), to which an input torque an be applied; a rotatably mounted first output shaft (30) and a rotatably mounted second output shaft (40), which are arranged parallel and are connected to each other by means of an output transmission stage in such a way that aid output shafts rotate oppositely, preferably at the same rotational speed, when an input torque is applied to the input shaft (20) at any shifting level of the shiftable transmission (1); a first coupling (50), which is designed to selectively connect an disconnect the input shaft (20) and the first output shaft (30), a first shifting level of the shiftable transmission (1) being realized in the coupled state, in which first shifting level the input shaft (20) and the first output shaft (30) are connected to each other in such a way that the input torque is transferred from the input shaft (20) to the first output shaft (30) without step-up or step-down, preferably without redirection and without a spur gear stage.

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 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 gear spindle device for a rolling mill includes: a spindle outer cylinder having, at a first end side, an inner circumferential surface provided with an inner circumferential gear; a spindle inner cylinder having an outer circumferential surface provided with an outer circumferential gear which engages with the inner circumferential gear; a seal member disposed between the spindle outer cylinder and the spindle inner cylinder, for holding a lubricant oil at an engagement portion between the inner circumferential gear and the outer circumferential gear; and a coolant supply unit disposed at an opposite side to the seal member across the engagement portion in an axial direction of the spindle outer cylinder, for supplying a coolant toward the spindle outer cylinder in a formation region of the engagement portion where the engagement portion is formed.

A gear spindle device for a rolling mill includes: a spindle outer cylinder having, at a first end side, an inner circumferential surface provided with an inner circumferential gear; a spindle inner cylinder having an outer circumferential surface provided with an outer circumferential gear which engages with the inner circumferential gear; a seal member disposed between the spindle outer cylinder and the spindle inner cylinder, for holding a lubricant oil at an engagement portion between the inner circumferential gear and the outer circumferential gear; and a coolant supply unit disposed at an opposite side to the seal member across the engagement portion in an axial direction of the spindle outer cylinder, for supplying a coolant toward the spindle outer cylinder in a formation region of the engagement portion where the engagement portion is formed.

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.

The invention relates to a shiftable transmission (1) having at least two shifting levels, preferably for use in rolling mill technology, said shiftable transmission comprising: a rotatably mounted input shaft (20), to which an input torque an be applied; a rotatably mounted first output shaft (30) and a rotatably mounted second output shaft (40), which are arranged parallel and are connected to each other by means of an output transmission stage in such a way that aid output shafts rotate oppositely, preferably at the same rotational speed, when an input torque is applied to the input shaft (20) at any shifting level of the shiftable transmission (1); a first coupling (50), which is designed to selectively connect an disconnect the input shaft (20) and the first output shaft (30), a first shifting level of the shiftable transmission (1) being realized in the coupled state, in which first shifting level the input shaft (20) and the first output shaft (30) are connected to each other in such a way that the input torque is transferred from the input shaft (20) to the first output shaft (30) without step-up or step-down, preferably without redirection and without a spur gear stage.

A rolling mill for producing rolling mill product is provided. The rolling mill includes a rolling mill line that moves the rolling mill product. A plurality of rolling mill stands are coupled to the rolling mill line that receives the rolling mill product and rolls the rolling mill product. A plurality of speed measuring devices that are positioned in close proximity to each rolling mill stand, where each speed measuring device measures the speed of the rolling mill product as it passes the speed measuring devices. A control device receives information associated with the speed measuring devices and adjusts the speed of the rolling mill product for any speed differential that might exist between any of the rolling mill stands.