20090134076 | Screen Changer - The invention relates to a screen changer in a system that processes flowable plastic, with an element that is movable between two positions, wherein the movable element is movable by a hydraulic cylinder, and with a motor that operates one of the hydraulic pumps, wherein a hydraulic supply line runs from the hydraulic pump to the hydraulic cylinder, wherein a first hydraulic pump is called the volume pump and a second is called the high-pressure pump, wherein the high-pressure pump has a lower volume capacity relative to the volume pump, but builds up a relatively higher pump pressure, with a non-return valve in the supply line, which optionally enables or interrupts the hydraulic connection between the volume pump and the hydraulic cylinder, and a high-pressure line, which pumps the hydraulic fluid from the high-pressure pump past the non-return valve to the hydraulic cylinder. | 05-28-2009 |