A material processing device has a rotor coupled to a rotatable shaft, and a rotor control system. The rotor control system comprises a rotor control mechanism with a first engagement member that is engagable with a second engagement member coupled to the shaft. The rotor control mechanism is operable into and out of an engaged state in which the first and second engagement members are engaged with one another. In the engaged state, the rotor control mechanism is operable in a locking mode in which the first engagement member is fixed in position to prevent rotation of the shaft, or in a rotation mode in which the first engagement member is movable to rotate the shaft. The material processing device may be a crusher, a shredder or a milling machine.

A material processing device has a rotor coupled to a rotatable shaft, and a rotor control system. The rotor control system comprises a rotor control mechanism with a first engagement member that is engagable with a second engagement member coupled to the shaft. The rotor control mechanism is operable into and out of an engaged state in which the first and second engagement members are engaged with one another. In the engaged state, the rotor control mechanism is operable in a locking mode in which the first engagement member is fixed in position to prevent rotation of the shaft, or in a rotation mode in which the first engagement member is movable to rotate the shaft. The material processing device may be a crusher, a shredder or a milling machine.

A hammer mountable at a rotor of a horizontal shaft impact crusher (HSi-crusher), the hammer including a front face, a rear face and at least one recess projecting inwardly into a main body of the hammer from the front face. The at least one recess being arranged to receive an attachment element to mount the hammer at a hammer lifting device.

A hammer mountable at a rotor of a horizontal shaft impact crusher (HSi-crusher), the hammer including a front face, a rear face and at least one recess projecting inwardly into a main body of the hammer from the front face. The at least one recess being arranged to receive an attachment element to mount the hammer at a hammer lifting device.

A rotor locking device in a crusher is arranged for locking a rotational position of a rotor shaft. A shaft engager includes a female toothed mating surface for coaxial engagement with a male mating surface at an end of the rotor shaft to rotationally interlock the same. A fastening portion with engager apertures overlaps with a bearing mount surrounding the rotor shaft so it can be fastened therewith. The engager apertures are circumferentially elongated in order to accommodate alignment with fastening points in the bearing mount, at least when a closest rotational mating position is chosen for alignment. This enables any rotational position of the rotor shaft to be locked for safety before having to access the crusher chamber, especially when the rotor of the crusher has become blocked and requires maintenance.

A rotor locking device in a crusher is arranged for locking a rotational position of a rotor shaft. A shaft engager includes a female toothed mating surface for coaxial engagement with a male mating surface at an end of the rotor shaft to rotationally interlock the same. A fastening portion with engager apertures overlaps with a bearing mount surrounding the rotor shaft so it can be fastened therewith. The engager apertures are circumferentially elongated in order to accommodate alignment with fastening points in the bearing mount, at least when a closest rotational mating position is chosen for alignment. This enables any rotational position of the rotor shaft to be locked for safety before having to access the crusher chamber, especially when the rotor of the crusher has become blocked and requires maintenance.

A material processing unit has a movable tool accommodated in a housing. The housing includes a housing part which can be moved between an open position and a closed position relative to a further housing part. A safety device prevents any opening of the housing when the tool is driven and/or prevents any driving in the open position. The safety device includes at least two actuators and a controller. A first actuator locks the housing part in the closed position. A second actuator causes, supports and/or permits a movement of the housing part. Sensors are assigned to the actuators. A controller is designed to control the drive and the actuators and to receive the actuation states detected by the sensors. A method for opening/closing a housing of a material processing unit is also provided.

A material processing unit has a movable tool accommodated in a housing. The housing includes a housing part which can be moved between an open position and a closed position relative to a further housing part. A safety device prevents any opening of the housing when the tool is driven and/or prevents any driving in the open position. The safety device includes at least two actuators and a controller. A first actuator locks the housing part in the closed position. A second actuator causes, supports and/or permits a movement of the housing part. Sensors are assigned to the actuators. A controller is designed to control the drive and the actuators and to receive the actuation states detected by the sensors. A method for opening/closing a housing of a material processing unit is also provided.

A mobile shredder for metal materials comprising a feeding device, a shredding mill with a plurality of hammers associated with a rotor, and a removal device and an actuating device are provided, wherein: the feeding device comprises a hopper and a shredder with a first toothed roller and a second toothed roller that rotates in the opposite direction to that of the first roller and at a greater speed. The actuating device comprises a single motor. A control system is also provided with a plurality of hydraulic pumps for moving the rollers and a hydraulic clutch with a variable flow for moving the rotor, the plurality of hydraulic pumps and the hydraulic clutch being joined to the motor. The control system is configured to modify the rotational speed of the toothed rollers based on the motor load associated with the shredding mill; and the devices are mounted on a frame.

The invention relates to a mechanical powder grinder comprising a casing supporting a first rotating grinding member and a second grinding member fixed relative to the casing, each of said first and second members being made of an electrically conductive material. According to the invention, the grinder includes an electrical control circuit providing at least one primary electrical connection between the first and second grinding members, and comprising at least one device for measuring an electrical parameter of said circuit. The grinder further comprises a processing device configured to detect an additional connection between the two grinding members, in particular due to the presence of a foreign body between said members, on the basis of the measured value of said parameter.