Abstract: A reciprocating piston machine is provided having at least one membrane (1) produced from an elastomeric material and an oscillating reciprocating drive that acts on a center zone (3) of the membrane (1). Between the center zone (3) of the membrane and its circumferential edge zone (5), a deformable membrane zone (M) is provided that is deformed during the oscillating pumping movements. The reciprocating piston machine according to the invention is characterized in that the work and/or auxiliary membrane (1), in its deformable membrane zone, is provided with at least two cantilever-type annular zones (7, 8) that merge into each other in a reduction of cross-section (9) of the membrane (1) and in that the membrane cross-section, starting from the reduction of cross-section (9), enlarges in the annular zones (7, 8). The membrane of the reciprocating piston engine according to the invention is very durable and functions with little noise.

Abstract: A pump is provided having at least one shield valve controlled by the conveyed medium and having a valve disk (4) of flexible material which is clamped in a central region and is movable between an open and a closed position, in which closed position the valve disk (4) closes at least one valve opening (9). The pump according to the invention includes extensions (11) that project from the valve disk (4) and/or on a valve abutment surface (10) arranged on a side remote from the valve opening (9), for avoiding a sudden flat abutment of the valve disk (4) on the valve abutment surface and/or for limiting the valve opening movement. The pump according to the invention is distinguished by a particularly low noise operation.

Abstract: The invention relates to a diaphragm pump (1) including a working diaphragm (3) that, during pumping movements, oscillates between a bottom dead center and a top dead center. The working diaphragm (3) delimits a pump chamber (7) between itself and a concave pump chamber wall (6) and when located at the top dead center position, the working diaphragm (3) rests against the pump chamber wall (6). The working diaphragm (3) has an inner and an outer annular zone (8, 9), which can be deformed during pumping movements, and a stiffened diaphragm area which, in essence, cannot be deformed during pumping movements is placed between these annular zones (8, 9). This non-deformable diaphragm area can be stiffened, for example, by stiffening ribs (10), which are radially oriented and spaced apart in the circumferential direction.

Abstract: A pump (1) with an oscillating part having a housing (2) with a working chamber (3) and a crankcase (4) defined from the working chamber by the pump part. A pump drive mechanism (6) with a drive shaft (7) is located inside the crankcase (4) and the drive shaft is mounted on bearings (8, 9) that are arranged in the walls of the crankcase. The pump has a suction inlet separate from the crankcase. The pump (1) includes at least one flow channel in the crankcase wall for compensating pressure in the crankcase when the pump part oscillates and a flow damper arranged in the at least one flow channel. In a preferred embodiment, the at least one passage hole having at least one bearing therein is configured as the flow channel.

Abstract: A measuring gas pump (1) including a pump housing (2) with a pump chamber (3) inside which is sealed by a working membrane (5). The membrane (5) is connected: by a connecting rod (8) or a similar type of lifting device to a crank mechanism (9). A heating device is provided in the upper area of the pump housing, specifically in the pump head (10). On one hand, in the drive-transmission area between the head of the connecting rod (6) on the membrane side and the crank mechanism (9), there are holes (11) for the reduction of heat transfer to the crank mechanism which are spaced in a longitudinal direction of the connecting rod and which are also diametrically opposed, in peripheral direction, with a resulting reduction in heat conductivity. On the other hand, there is an enlargement of the surface area, at least in the area adjacent to the crank mechanism, for purposes of heat dissipation, specifically through cooling ribs (12).

Abstract: A rotary piston displacement device having an impeller housng with an approximately cylindrical receiving chamber in which an approximately cylindrical piston, which has a smaller outside diameter than and which is mounted eccentrically relative to, the receiving chamber, is provided mounted on an eccentric drive. The rotary piston forms an approximately sickle-shaped interspace between its outer wall and the inner wall of the receiving chamber. This interspace is divided into a pressure chamber and a suction chamber by a separating crosspiece that is placed between an inlet opening that is located inside the housing and an outlet opening. The outer and inner fixing locations of the separating crosspiece, which is connected to the housing on the one side and the piston on the other side, are offset with respect to one another in the peripheral direction of the rotary piston.

Abstract: A laboratory pump unit (1) for pipetting, filtering, and exhausting a gaseous or liquid fluid is provided. The laboratory pump unit (1) includes a pump (3), which can be connected on the suction side and/or the pressure side to a pipette (4) or other fluid receiver, for suctioning or ejecting the fluid. The laboratory pump unit includes, among other elements, a secondary tube (9, 10) that is connected to the suction tube and/or pressure tube (6, 7) that is connected to the pipette (4) or fluid receiver on the one hand and the pump (3) on the other hand, and is open to the atmosphere, and includes a throttle (11, 12) for limiting the amount of air drawn in or ejected. The laboratory pump unit (1) is operated in “open” pump operation on the suction side and pressure side with a precisely adjusted tube pressure in the suction tube or pressure tube (6, 7), which cannot be exceeded or fallen below by the pump (3).

Abstract: A membrane pump (104) with an operating membrane (1) delimiting a conveying space (2), and a supplemental membrane (3) arranged on the side of the operating membrane (1) facing away from the conveying space (2), with a membrane interspace (4) provided between the operating membrane (1) and the supplemental membrane (3) as well as with a pump drive for oscillating movement of the operating and the supplemental membranes (1, 3) in the same direction. The membrane interspace (3) is joined with at least one suction channel (7) for relieving pressure of the membrane interspace (4). The membrane interspace (4) is pneumatically joined through the at least one suction channel (7) with the suction side of this membrane pump (104). The membrane pump of the invention (104) has a high suction capacity without the problem of buckling of the elastic operating membrane (1) in the intake phase.

Abstract: A rotary piston displacement device having an impeller housng with an approximately cylindrical receiving chamber in which an approximately cylindrical piston, which has a smaller outside diameter than and which is mounted eccentrically relative to, the receiving chamber, is provided mounted on an eccentric drive. The rotary piston forms an approximately sickle-shaped interspace between its outer wall and the inner wall of the receiving chamber. This interspace is divided into a pressure chamber and a suction chamber by a separating crosspiece that is placed between an inlet opening that is located inside the housing and an outlet opening. The outer and inner fixing locations of the separating crosspiece, which is connected to the housing on the one side and the piston on the other side, are offset with respect to one another in the peripheral direction of the rotary piston.

Abstract: A measuring gas pump (1) including a pump housing (2) with a pump chamber (3) inside which is sealed by a working membrane (5). The membrane (5) is connected by a connecting rod (8) or a similar type of lifting device to a crank mechanism (9). A heating device is provided in the upper area of the pump housing, specifically in the pump head (10). On one hand, in the drive-transmission area between the head of the connecting rod (6) on the membrane side and the crank mechanism (9), there are holes (11) for the reduction of heat transfer to the crank mechanism which are spaced in a longitudinal direction of the connecting rod and which are also diametrically opposed, in peripheral direction, with a resulting reduction in heat conductivity. On the other hand, there is an enlargement of the surface area, at least in the area adjacent to the crank mechanism, for purposes of heat dissipation, specifically through cooling ribs (12).

Abstract: A plastic optical fiber having a low-loss, light-guiding plastic core surrounded by an inner, low-loss layer of a smaller refractive index and by an outer, stronger light-absorbing layer. The low-loss, light-guiding plastic core can also be surrounded by a light-absorbing layer.

Abstract: A scanning head for eddy-current testing includes a probe coil configuration disposed on a film on a film base. The film base is matched to a shape of an object to be tested. This allows quick, low-interference eddy-current testing. A method for producing a scanning head for an eddy-current test and an eddy-current test method are also provided.

Abstract: A process for evacuating a wet or liquid conveying medium out of the treatment chamber (2) of a treatment device (1) using a pumping device (3) that has a single or multi-stage suction pump (4) is provided, where the conveying medium is cooled off during the evacuation along the flow path such that the conveying medium in the pumping device (3) is in the liquid aggregate state or is converted into that state. A treatment device for carrying out the process as well as a single or multi-stage suction pump for this treatment device is also provided.

Abstract: A plastic optical fiber having a low-loss, light-guiding plastic core surrounded by an inner, low-loss layer of a smaller refractive index and by an outer, stronger light-absorbing layer. The low-loss, light-guiding plastic core can also be surrounded by a light-absorbing layer.

Abstract: The invention relates to a method according to the eddy-current testing principle, and to a device for determining the thickness of an electrically conductive protective layer which is applied to an electrically conductive base material. The electrical conductivities of the protective layer and of the base material are different from each other. An excitation coil through which a high-frequency electric current is passed is brought near to the protective layer, so that an electric eddy current is produced in the protective layer and possibly in the underlying base material. A parameter related to the impedance of a probe coil is determined and is used as a basis for determining the thickness of the protective layer, for example by comparison with known reference values. The frequency of the high-frequency electric current is selected in such a way that the thickness of the protective layer is determined unambiguously for a ratio of the electrical conductivities of between 0.7 and 1.5.

Abstract: A reciprocating piston machine (1) has an inlet valve (9) on the suction side and an outlet valve (10) on the delivery side, which valves exhibit a valve body having a valve disc (11, 12) comprising of an elastomer, whereby the compression chamber (6) sealed off by the reciprocating piston or similar displacer (2) and by the valves (9, 10) has a pressure relief connection between compression chamber and atmosphere. To be able to bring the compression chamber (6) quickly to atmospheric pressure after the reciprocating piston machine (1) has been put out of operation and to be able to bring about the restart of the reciprocating piston machine (1) so as to be load-free in this respect, the valve disc (11,12) of the valve (9, 10) on the delivery side and/or on the suction side has at least one capillary passage (18, 19) as pressure relief connection.

Abstract: A two-stage positive displacement pump (1) is used in particular to operate in conjunction with a turbomolecular pump (2) that can be placed ahead of it in series. The two-stage positive displacement pump (1) is configured as a hybrid pump (3) that has on the medium-entry side a reciprocating pump (5) with a comparatively large displacement area (6), whereby its piston-cylinder space (7) is sealed off with respect to the crank area (8) by means of a sealing membrane (9). Also as a part of this two-stage positive displacement pump (1) which forms the hybrid pump (3), there is placed in series behind the reciprocating pump (5) a diaphragm pump (10), whose displacement area (11) is noticeably smaller compared to that of the reciprocating pump (5).

Abstract: A diaphragm pump (1) with a working diaphragm (16) is provided with an additional diaphragm (26) arranged at a distance (a) from the working diaphragm (16), between the working diaphragm and eccentric drive (7). The diaphragm pump (1) provided with an additional diaphragm may alternatively have a swing connecting-rod with U packing ring instead of the working diaphragm (16). The additional diaphragm, together with a lateral confinement formed by an intermediate casing (4) of the pump case (2), composes an essentially closed diaphragm interspace. A deformable annular zone (30) of the additional diaphragm (26) has a channel-like convexity (31) which, in the undeformed condition of the diaphragm, points in the direction of the eccentric drive (7). For this purpose, the elastically deformable annular zone (30) of the additional diaphragm (26) has a radial expanse wider than the deformable annular zone (24) of the working diaphragm (16).

Abstract: A membrane pump has a housing which includes a pump head provided with an internal recess. The pump head is further provided with an inlet opening and an outlet opening which communicate with the recess and are disposed next to one another near an edge of the housing. A membrane extends across the recess and is clamped at its edges by the housing. The membrane and recess together define a pumping chamber. A segment of the membrane is held stationary against the pump head by a clamping finger and forms a seal with the pump head. The seal extends radially between the inlet and outlet openings from the periphery of the pumping chamber to its center. A drive successively urges circumferrentially successive segments of the unconfined part of the membrane into sealing engagement with the pump head to thus direct fluid from the inlet opening to the outlet opening.

Abstract: A device for flushing the urinary bladder (1) has an instrument inserted from the outside into the inside of the bladder and a feed line (17a, 17b, 10) from a supply receptacle (16) feeding pressurized flushing liquid and a drain line (11, 15) to a drain. The interior bladder fluid pressure is regulated by a pressure regulator connected through the feed line to the bladder. The regulator is held at constant height. The pressure regulator has a valve (31, 32) controlling the flow cross-section which is in turn controlled by the pressure sensor (27) located on the side of the valve facing the bladder and ascertaining the pressure in the feed line (17b, 10). The feed conduit between the regulator and the bladder has a constant flow resistance smaller than the minimum possible flow resistance of the drain conduit multiplied by a maximum pressure variation P.sub.Fmax and divided by a maximum allowable bladder pressure P.sub.Bmax.