Abstract: A method and a device for producing a tubular object from thermoplastic material. The device includes a die having a movable die body for altering the cross-sectional surface of the die opening, a plunger for extruding a specific quantity of plastic material through the die, and a withdrawal unit for guiding the tubular plastic object emerging from the die. The movements of the withdrawal unit, plunger and die body are controlled such that movement of the withdrawal unit is carried out according to a freely adjustable velocity profile over the path of the withdrawal unit. Movement of the plunger is carried out according to a freely adjustable velocity profile over the plunger path and movement of the die body is carried out according to a freely adjustable position profile over the path of the withdrawal unit or plunger. In this manner, the wall thickness of the tubular object may be adjusted with high accuracy over its length.

Abstract: Accommodated inside the housing (1) of a bowl-and-roller mill is a rotating grinding bowl (3) with segments (7) that stationary rollers (8) roll over. Blades (20) are cast onto the outside circumference of a nozzle ring (15).

Abstract: An owl-mill crusher with stationary grinding rollers (6) inside a housing (1) that roll over a grinding bowl (3) resting on a rotating grinding-bowl support (5). An air box (8) is provided below the grinding bowl (3). A circular-conical disk (17) is secured to the grinding-bowl support (5) with its outer edge pointing down. A stationary cleanout arm (24) is positioned above the disk (17) with one end extending into the extraction shaft (20) of the removal container (21), which is mounted on the side of the housing. Several blades (25) are secured to the bottom of the disk.

Abstract: Grinding elements of a mill rotating inside a mill housing are sealed off relative to the mill housing by an isolating air chamber. The isolating air chamber is limited by sealing rings abutting against the mill elements and a sealing ring housing. The sealing ring housing is connected to the mill housing. An intermediate insulation is provided between the sealing ring housing and the mill housing. The mill housing is sealed off to the outside by a collar.

Abstract: Means of sealing off the inside of a pulverizer, especially a bowl-mill pulverizer that has a horizontal rotating bowl-type grinding ring rigidly connected to a shaft, from the outside atmosphere. The means comprise a barrier-air chamber and ring seals in a ring-seal holder. The ring seals are slide rings that fit into grooves. They demarcate the barrier-air chamber. The ring seal on the side of the chamber that faces the inside of the pulverizer does not fit as tightly against its opposing surface (the shaft in one embodiment) as those on the other side.