Abstract: A reciprocating piston machine (1) with at least one inlet and/or outlet valve that has a strip, tongue or lamella shaped closing member (5). The opening movements (8) of the closing member (5) are limited through a stroke restrictor (6) assigned to each valve. The stroke restrictor (6) has or defines at least one ventilation hole (8) inside the contact area of the closing member (5). This ventilation hole (8) prevents the formation of air cushions (7) between the closing member (5) and the corresponding stroke restrictor (6) effectively. In the absence of the ventilation hole (8), the air cushion (7) can limit the opening movements of the closing member (5) prematurely, which in turn could lead to the generation of additional noise.

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 diaphragm pump, especially a microdiaphragm pump, with a crank drive (1) having a connecting rod (2) and an elastic diaphragm (3) connected with the connecting rod (2) has on the back side of the diaphragm facing away from the compression chamber at least one undercut fastening opening (8) for insertion of the complementarily formed attachment end of the connecting rod. In order to be able to fix the diaphragm (3) so precisely on the connecting rod (2) that radial as well as axial forces do not move it from its position relative to the connecting rod (2), and in order that the diaphragm (3) is exposed to as little additional flexing work as possible, the connecting rod (2) is provided on its attachment end with a support surface (4) for underside support of the central diaphragm area having a bearing surface (5).

Abstract: An evaporation system for separation of a fluid mixture into its component parts, especially for the reclamation of solvents, has a vacuum pump connected to the evaporator, especially a rotation evaporator, with at least one separator being connected to the suction side of the vacuum pump and at least one secondary condenser being connected at the pressure side of the vacuum pump. A fine regulating valve (8) is installed in the connecting pipe (7) between the rotation evaporator (2) and the separator (9), which is connected in front of the vacuum pump (10), for regulation of the boiling pressure.

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 pump stand (1) has a base plate (2) with a pump (3) mountable thereon. The pump (3) has supports (4) serving as its vibration damping elements with which it stands upon the base plate (2). Coupling elements (5) are provided on the pump underside and on the base plate upper side, for coupling the pump (3) and the base plate (2) with each other, whereby the coupling elements essentially engage in the assembled state of the pump without locking. The coupling elements (5) are located at a defined place suitable for pumps of different sizes.

Abstract: A diaphragm pump (1) has a shaped diaphragm (2) of elastic material. The central zone (3) of the diaphragm (2) is thickened in the direction of stroke and is surrounded by a flexible annular zone (5) held on the pump case by an external clamping edge (6). The central zone (3) of the diaphragm (2) is engaged by a connecting rod (11) with which the shaped diaphragm (2) is displaceable from a top to a bottom dead-centre position and vice versa. Radial ribs (19) as well as stabilizing ribs (19) extending in the circumferential direction are arranged on the underside (17) of the annular zone (5). Therefore a shaped diaphragm (2) is obtained which in the annular zone (5) is flexible about a circumferential line, but which nevertheless exhibits comparatively high flexural strength about a diametral line. Deformation of the shaped diaphragm (2) under vacuum is thereby reduced.

Abstract: A diaphragm pump 1 has a reciprocating piston 2 operated with the aid of a connecting rod 5 and by this means moves an attached diaphragm 4 fixed in the pump housing 3. The connecting rod 5, in turn, is acted upon and driven at the end facing away from the reciprocating piston 2 by an eccentric 6 or a cranked portion of the drive shaft 11. The rotating masses and at least part of the oscillating masses of the pump are balanced by at least one fixedly mounted counterweight 7 moving in synchronism therewith. For the automatic correction of varying out-of-balance conditions due to variable gas forces or medium forces, a self-regulating system of rolling elements 12 is provided in an annular, empty cavity 9 that is arranged concentrically to the axis of shaft rotation and is situated within a co-rotating housing 10.

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 diaphragm pump with a driving motor has arranged in a case (5) at lease one drive (3) for transferring the pump movement to a pump diaphragm (4a). The case (5) of the diaphragm pump is essentially formed by at least one extrusion (6) configured to accommodate the drive(s) (3) and the driving motor (2). The extrusion (6) carries the driving motor (2), the drive(s) (3) and the pump head(s) (4). The extrusion (6) enables the pump case (5) to be specially dimensionally stable, to be manufactured at reasonable price, and has substantially smooth external surfaces. It is therefore easy to clean.

Abstract: A pump stand (1) has a base plate (2) for mounting thereon a pump (3) and at least one of a control unit (6) and a vacuum controller (7). The pump stand (1) has for this purpose a plurality of push-in or snap-in connections (5) enabling pump components or accessory units, particularly the pump (3) itself, to be simply exchanged. By this means a pump stand (1) of straightforward arrangement ensues, which provides a large number of possibilities for variation and can be simply combined with pumps of different type or different output.

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.

Abstract: A measuring gas pump (1) has a pump chamber (3) closed by means of a working diaphragm (6). The strokes (double-headed arrow 26) are imparted to the working diaphragm (6) by way of a connecting rod or like lifting mechanism (9) from a crank mechanism (10). A heat source (16) is provided in the pump head (15). Provided between the connecting rod head (8) and the crank mechanism (10), there is a heat dissipation barrier (19 and/or 27) with respect to the measuring gas. By means of the measuring gas pump (1), the gas to be delivered thereby can be kept better to the temperature of the gas sampling condition and unwanted condensation of constituents of the gas to be analyzed and falsifications of the measurement result can be avoided or at least significantly reduced.

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 has a first fluid-operated valve which opens when the diaphragm performs a suction stroke and a second fluid-operated valve which opens when the diaphragm performs a compression stroke. The volumetric efficiency of the pump is enhanced by constructing at least one of its valves in such a way that the central portion of a resilient disc-shaped valving element, whose marginal portion bears against a seat when the valve is closed, abuts a supporting surface having a diameter selected in dependency on the diameter of the valving element, the thickness of the valving element and the Shore hardness of the material of the valving element in such a way that the selected frequency of the diaphragm in actual use of the pump induces a resonant frequency of the valving element. This also contributes to a reduction of noise and renders it possible to reduce wear upon the valving element and the adjacent parts of the respective valve.

Abstract: A diaphragm pump wherein the marginal portion of a contoured diaphragm is clamped between the cover and the case of the pump housing and the reinforced central portion of the diaphragm is reciprocated toward and away from the inner side of the cover by the connecting rod of a crank drive. The front side of the diaphragm and the inner side of the cover define a variable-volume pumping chamber which receives a fluid medium by way of an inlet and discharges the aspirated fluid medium by way of an outlet in the cover. The diaphragm has an intermediate portion which connects the central and marginal portions and is provided with an annular flexure zone including an annular protuberance at the rear side of the diaphragm.

Abstract: A diaphragm pump wherein that side of the diaphragm which faces away from the pumping chamber is adjacent a noise intercepting insert. The insert is traversed by the connecting rod of the drive which oscillates the central portion of the diaphragm to draw a fluid into and to expel the drawn fluid from the pumping chamber. A deformable wall of the insert has a marginal portion which is attached to the housing, and this wall is separated from the diaphragm by an elastic distancing cushion of foam rubber or other sound absorbing material. The cushion can constitute a ring or it can consist of a set of projections which are affixed to or integral with the wall and face of the diaphragm. The cushion is compressed between the head of the connecting rod and the wall so that the latter is maintained in stressed condition.