Abstract: A diaphragm pump for conveying liquids for application in a sterile environment includes passageways for conduction of a liquid, and check valves for controlling a flow of liquid through the passageways. The diaphragm pump is constructed in such a way that all surfaces of the passageways in contact with the liquid being conveyed are disposed at a slant. In addition, all transitions between liquid-conducting surfaces have a gradual configuration. For drainage of the diaphragm pump, the shutoff elements of the check valves are lifted off their valve seat through temporary generation of a magnetic field.

Abstract: The drill bit (14) passes through a drilling bush (2) for guiding said drill bit. The drilling bush (22) is pressed against the workpiece (10). However, the drilling bush does not terminate flush with the workpiece, but comprises a linear supporting edge (28) that overlaps the apex of the curvature of the workpiece. This prevents the drilling bush from sliding off a curvature of the workpiece surface.

Abstract: The drill bit (14) passes through a drilling bush (2) for guiding said drill bit. The drilling bush (22) is pressed against the workpiece (10). However, the drilling bush does not terminate flush with the workpiece, but comprises a linear supporting edge (28) that overlaps the apex of the curvature of the workpiece. This prevents the drilling bush from sliding off a curvature of the workpiece surface.

Abstract: A reversing valve for a compressed air membrane pump in which an equilibrium state of the main piston in the neutral position, leading to stoppage of the pump, is prevented by disposing the main system piston and the pilot system piston immediately adjacent to one another.

Abstract: The invention relates to a system for the circulatory conveyance of media, with a drive and with two conveying chambers, the first conveying chamber constituting a feed chamber and the second conveying chamber a return chamber.

Abstract: A reversing valve for a compressed air membrane pump in which an equilibrium state of the main piston in the neutral position, leading to stoppage of the pump, is prevented by disposing the main system piston and the pilot system piston immediately adjacent to one another.

Abstract: A diaphragm for a pump, in particular a double diaphragm pump for conveying high-purity products, having peripheral radially offset annular beads, such that one of the annular beads is a grooved bead having a groove along its interior surface, and a clamping ring inserted in the groove formed therein, and wherein the groove is in communication with a pressure medium.

Abstract: A double membrane pump comprising a central housing (1), two coaxial product chambers (6) in the central housing, suction and pressure valves for each product chamber, two membranes (7) sealing off the product chambers externally from coaxial pressure fluid chambers (8), piston rods (13) guided in external seals, a U-shaped external crosspiece (17) connecting the piston rods of the membranes and a control block for reciprocally pressurising the pressure fluid chambers with pumping medium and comprising a slide valve (20) actuated by the movement of the membranes. The pump provides a very short path for the pumping flow, with only two changes in direction, and only static seals. It can be made wholly of plastics materials and is particularly suitable for high-purity products in the semiconductor industry, in biotechnology and in the pharmaceutical, cosmetic and foodstuffs industries.

Abstract: A double diaphragm pump having diaphragms connected by a coupling rod and separating two diaphragm chambers, a control spool displaceable in dependence on the position of the diaphragms, with closure means for alternate freeing and closing control passages arranged in a control spool housing for alternate pressurizing and relieving of a driving medium chamber with driving medium, and an actuating member coupled with the diaphragm movement and magnetically with the control spool.

Abstract: A double diaphragm pump with a novel compressed air control means is described, in which, in addition to a main control valve piston for the control of the compressed air fed to the two air chambers of the diaphragm pump, a pilot control valve means is provided, which drives the main control valve piston pneumatically such that the main valve is retarded at approximately half of the length of its stroke, at which point the main control valve piston separates the two air chambers both from the compressed air inlet and from the exhaust air outlet, and instead connects them together for the purpose of pressure equalization. By this measure in conjunction with novel sealing means for the moving parts, the pressure losses are reduced and thus the efficiency of the pump is increased, the danger of icing up the air exhaust is reduced, and separate provisions for lubrication, such as oil mist lubrication, are dispensed with.