Abstract: A method is disclosed for operating a hydropneumatic device (1) for pressure multiplication, with a working piston and a multiplier piston (9) for pressure multiplication on to the working piston and with an accumulator piston (3) for an urgent movement of the working piston by forcing hydraulic fluid out of an accumulator chamber (12), wherein a ventilation opening (13) is provided in the accumulator chamber (12), through which air drawn into the accumulator chamber (12) can be discharged during a maintenance process. According to the invention for an operating mode in which power strokes are executed, the hydraulic fluid volume in the accumulator chamber (12) is discharged below the ventilation opening (13) in the accumulator chamber. The hydraulic fluid pump is additionally disclosed.

Abstract: Proposed is a hydro-pneumatic pressure transformation device with a working piston (3) and a transformer piston (17) for transforming the pressure exerted upon the working piston (3), wherein the transformer piston (17) features a working stroke chamber (19) for the power stroke and a return stroke chamber (15) for the return stroke, and wherein the working stroke chamber (19) can be subjected to an operating pressure for the power stroke. According to the invention, pressurization means are provided for changing over the return stroke chamber (15) between a low pressure that lies at least approximately in the range of atmospheric pressure or at atmospheric pressure and an intermediate pressure that lies between the low pressure and the operating pressure during the course of the power stroke and the return stroke. A method for operating a hydro-pneumatic device is also proposed.

Abstract: A method of manufacturing printed circuit boards is disclosed wherein metallic conductive structures are produced in a desired pattern on a carrier board of isolating material. The method begins with the provision of a carrier board having a metal foil laminated to its surface and thereafter forming conductive traces on the carrier board, deactivating the carrier board to remove substantially all substances deposited on the carrier board other than the conductive traces and forming final conductive structures by electroless chemical metal deposition on the pattern of conductive traces. Circuit boards manufactured in accordance with such a method will have final conductor structures with base layer portions of the original laminated metal foil. In a preferred embodiment, the step of deactivating the carrier board involves rinsing the carrier board with hydrochloric acid.