Abstract: A roll stand with at least one working roll for rolling strip material and with a hydraulic arrangement for controlling a roll gap of the roll stand, comprises at least one hydraulic adjustment unit for adjusting the roll gap, the hydraulic adjustment unit comprising a cylinder and an adjusting piston dividing the cylinder into a first chamber and a second chamber; a first double-acting valve arrangement and a second double-acting valve arrangement which are each connected to the first chamber and the second chamber for variable control of the adjusting unit, wherein the second double-acting valve arrangement is connected in parallel with the first valve arrangement and has a larger nominal volume flow than the latter; and wherein the adjusting unit can be pressurized with an working pressure of more than 200 bar.

Abstract: A hydraulic roll bending machine and method includes loading a plate between top and bottom rollers, receiving a user input indicative of a desired plate radius, calculating a pre-bend radius for the plate based on the desired plate radius and information from the material database, providing a bending signal to the actuator to position the at least one bending roller relative to the top and bottom rollers based on the pre-bend radius, providing a feed signal to advance a leading portion of the plate against the at least one bending roller, determining an actual pre-bend radius of the leading portion of the plate, and calculating an adjustment to the material database based on a difference between the pre-bend radius and the actual pre-bend radius.

Abstract: A hydraulic roll bending machine includes a frame, a plate roller rotatably connected to the frame, a hydraulic power unit associated with the frame, and a network of conduits fluidly connected to a main feed of hydraulic fluid and a main return of hydraulic fluid of the hydraulic power unit. At least one hydraulic actuator having a housing is associated with the plate roller. The housing forms one or more fluid passages therein that are fluidly connected with activation chambers of the at least one hydraulic actuator. A valve system is connected onto the housing and is in selective fluid communication fluid passages and also with the network of conduits. The valve system is arranged to selectively fluidly interconnect the one or more passages with the network of conduits to operate the at least one hydraulic actuator.

Abstract: Disclosed is a rolling mill, in particular a rolling mill having more than one mill stand, comprising at least two rolls (30) which are mounted in a roll bearing in a mill stand to absorb rolling forces, further comprising means (40) for moving at least one roll relative to the mill stand as well as means (50) for determining the roll pass, the determining means having a pass reference (54) and a spatial reference (56) as well as means (58) for measuring the relative position between the pass reference and the spatial reference. In order to create a rolling mill that provides as accurate information as possible about the roll pass, the pass reference and/or the spatial reference is/are arranged peripherally in relation to the power flow occurring between the roll and the mill stand.

Abstract: Straightening device for long or rod-shaped metal products, comprising an upper roll unit and a lower roll unit, wherein the upper roll unit is mobile and can be positioned vertically at least in the step where a passage gap of said products is set to a desired value, wherein a hydraulic safety/control device is associated with the lower roll unit and comprises a single-effect hydraulic actuator of the selectively yielding type when an overload condition higher than a predetermined value is detected on said lower roll unit.

Abstract: An apparatus for the electrohydraulic control of the parallelism of a roller in a bending machine for working metal pieces, has a first and second pumps for supplying with an operating fluid a first and second actuators, position transducers and a first and second proportional valves to adjust the flow of the operating fluid into the first and second actuators according to signals of the position transducers.

Abstract: A plate workpiece processing tool includes a first tool portion and a second tool portion. The first and second tool portions are arranged along an application axis in spaced relation to each other such that a plate workpiece can be disposed therebetween. The tool also includes two or more processing devices that are carried by the first tool portion, and one or more counter-devices that are carried by the second tool portion. The processing devices are rotatable, relative to the first tool portion, about a first rotational axis that extends perpendicular to the application axis and are arranged to follow each other along an axis extending perpendicularly to the application axis. The processing devices and the one or more counter-devices are selectively alignable to form a plurality of alternative device pairings for processing plate workpieces therebetween.

Abstract: A hot-rolling plant (50) for the production of metal strips comprising a roughing stand (2), a reheating furnace (3) or a maintenance tunnel for maintaining the temperature of the product, a pre-finishing mill train (4), comprising three or four stands, a finishing mill train (5), comprising two or three stands, for finishing the product, in which the work rolls of one stand are provided with their own motor drive, independent one from each other, so as to allow the peripheral speeds of both of said work rolls to be autonomously varied under rolling load.

Abstract: A device for measuring the roll gap (7) between the working rollers (1a: 1b) of a cold or warm rolling stand for rolling out narrow or wide strips of metal, especially NE metal strips, by means of roll gap sensors (6) whose signals are transmitted to the servo-valves of the compressed oil control as a roll gap setpoint value for the piston cylinder units influencing said roll gap (7), and used to provide a roller gap measurement which is also suitable for such cases involving the lateral progression of said strip. In order to achieve said aim, the position or travel sensor (6) is provided in at least one bending cylinder (5a;5b) for the working cylinder (1a, 1b) for indirect reference measurement of the roll gap via the positively or negatively acting bending cylinders (5a; 5b).

Abstract: Work rolls opposed to each other have shafts rotatably supported by upper and lower work roll chocks of a housing, a screw down device for applying a predetermined pressure to the upper work roll is provided in an upper portion of the housing, screw mechanisms capable of thrusting the work roll chocks in a horizontal direction are provided on an entry side or a delivery side of the housing, hydraulic cylinder mechanisms capable of thrusting the work roll chocks in the horizontal direction are provided on the other side, and contraction portions are provided in hydraulic supply and discharge pipes of the hydraulic cylinder mechanisms.

Abstract: There is described a method of controlling a long-stroke, hydraulic operating cylinder (1), in particular a screw-down cylinder for an edging stand, where the piston (4), to which a load can be applied at both ends, and which can be locked hydraulically along its stroke (s) in various working positions, is abruptly loaded with an external force after it has been locked. To create advantageous method conditions, it is proposed that the piston (4) be locked under a hydraulic pressure chosen in dependence on the respective working position, which hydraulic pressure decreases along the stroke (s) against the direction of action of the external force.