WO2013156087A1

WO2013156087A1 - Diaphragm pump, in particular for use as a detergent dosage pump

Info

Publication number: WO2013156087A1
Application number: PCT/EP2012/057319
Authority: WO
Inventors: Heribert Lohwieser; Wolfgang Sauer; Herbert Hunklinger; Rudolf Albrecht
Original assignee: Ecolab Inc.
Priority date: 2012-04-20
Filing date: 2012-04-20
Publication date: 2013-10-24

Abstract

A diaphragm pump (10), in particular for use as a detergent dosage pump, comprises a pump housing (12), wherein the pump housing (12) comprises at least a first connector (14) and a second connector (46), a fluid chamber (16) connected fluid permeable to the at least first connector (14) and second connector (46), a reciprocating moveable diaphragm (18) defining a wall of the fluid chamber (16),at least a first check valve (44) allocated to the first connector (14) and a second check valve (48) allocated to the second connector (46), a first eccentric (24) and a second eccentric (32),a driving means (30) for actuating the first and second eccentric (24, 32), wherein the diaphragm (18) is actuated by the first eccentric (24) by a connector rod (20), and the first check valve (44) and the second check valve (48) are actuated by the second eccentric (32). This has the advantage that by actuating the first and second check valve (44, 48) depending on the movement of the diaphragm (18), in particular by a coordinated rotational movement of the first and second eccentric (24, 32), a gas, for example air, trapped inside the fluid chamber (16) may be evacuated from the fluid chamber, thus providing a self-bleeding diaphragm pump (10).

Description

Diaphragm pump, in particular for use as a detergent dosage pump

Technical field of the invention The invention relates to a diaphragm pump, in particular for use as a detergent dosage pump.

Background of the invention Diaphragm pumps are usually used to supply metered quantities of liquids with various properties. Depending on the field of application, the pump behaviour is subject to various requirements in order to ensure that the delivered quantity of the metered medium is as precise as possible and remains constant for as long as possible. Diaphragm pumps are common industrial pumps that use positive displacement to move liquids. These pumps typically include a diaphragm and a fluid chamber, as well as check valves to prevent backflow. Diaphragm pumps can handle a range of media that include abrasive materials, acids, chemicals, or the like since the driving means of the pumps are normally separated and protected from the hydraulic part of the pump, which is in contact with the fluid to be pumped.

However, the design of diaphragm pumps known in the art suffer from the disadvantage that sometimes a small amounts of dirt may prevent the check valves to operate properly, resulting in a failure of the pump. A further disadvantage is, that a gas, for example air, may be trapped inside the fluid chamber during the operation of the pump, preventing a further pumping of a liquid.

It is therefore an object of the present invention to provide an improved diaphragm pump which is unsusceptible to small particles of dirt. Further it is desirable to reduce the risk of a gas, in particular air, to be trapped inside the fluid chamber. Further it is desirable to reduce the size of the diaphragm pump.

SUMMARY OF THE INVENTION

This object is solved by means of a diaphragm pump according to the invention.

In a general aspect of the invention the diaphragm pump, in particular for use as a detergent dosage pump, comprises a pump housing, wherein the pump housing comprises at least a first connector and a second connector, a fluid chamber connected fluid permeable to the at least first connector and second connector, a reciprocating moveable diaphragm defining a wall of the fluid chamber, at least a first check valve allocated to the first connector and a second check valve allocated to the second connector, a first eccentric and a second eccentric, a driving means for actuating the first and second eccentric, wherein the diaphragm is actuated by the first eccentric by a connector rod, and the first check valve and the second check valve are actuated by the second eccentric.

The diaphragm pump comprises a pump housing, which comprises at least a first connector and a second connector, wherein one connector may be connected to a fluid supply, wherein the other connector may be connected to a consumer being supplied with the fluid, for example an industrial washing machine. A fluid chamber is connected fluid permeable to the first and second connector, and in particular arranged between the first connector and the second connector, wherein one wall of the fluid chamber may be defined by a diaphragm, in particular by a reciprocating movable diaphragm, wherein the fluid chamber may be filled or emptied depending on the movement of the diaphragm. In order to define the flow direction of the pumped fluid, the diaphragm pump may comprise at least a first and a second check valve, wherein the first check valve is allocated to the first connector and the second check valve allocated to the second connector. Further, the diaphragm pump may comprise a first eccentric and a second eccentric, which may be actuated by a driving means, in particularly a stepper motor providing a high torque for actuating the first eccentric and the second eccentric. The first eccentric and the second eccentric may be designed as a first and a second eccentric wheel. The first eccentric and the second eccentric may comprise different eccentric trajectories, wherein the first eccentric may execute an eccentric movement around the first axis. The second eccentric may execute an eccentric movement around the first axis. The first axis may be a drive shaft of the driving means. The driving means may be actuating the first eccentric and the second eccentric simultaneously. The first eccentric and/or the second eccentric may be directly connected to the driving shaft of the driving means. The first eccentric and/or the second eccentric may be rotating with about the same rotational speed of the driving shaft of the driving means, in particular executing 360° rotational movements. The first eccentric may actuate the diaphragm by means of a connector rod, transferring the rotational, eccentric movement of the first eccentric into an essential translational movement of the diaphragm. The first check valve and the second check valve are actuated by the second eccentric, wherein the actuating of the first and second check valve is dependent to the position of the first and/or second eccentric, in particular relative to each other. The first and second check valves are arranged adjacent to the fluid chamber, in particular the first and second check valve almost form a part of the wall of the pump housing defining a wall of the fluid chamber. The diaphragm pump according to the present invention has a few advantages over devices according to the state of the art. For example, one advantage is that the diaphragm pump may be unsusceptible to a defect like a leakage due to a small particle hampering a proper functioning of the first and/or second check valve, by providing a spring-biased first and second check valve, actively actuated via the second eccentric. Further, the diaphragm pump according to the invention has the advantage that by actuating the first and second check valve depending on the movement of the diaphragm, in particular by a coordinated rotational movement of the first and second eccentric, a gas, for example air, trapped inside the fluid chamber may be evacuated from the fluid chamber, thus providing a self-bleeding diaphragm pump while at the same time increasing the insusceptibility to defects like a leakage due to spring- biased check valves. Further, the manufacturing costs of the diaphragm pump may be lowered due to the need for less accurate tolerances of the pump design. A further advantage of the diaphragm pump according to the invention is that due to the connection of the first and second eccentric to the driving shaft of the driving means the size of the pump may be further reduced.

In another embodiment of the invention the second eccentric is connected to the first eccentric. By connecting the second eccentric to the first eccentric, the two eccentrics may be rigidly coupled. Thus the position, in particular the eccentric position, of the second eccentric may be fixed relative to the position of the first eccentric. The first eccentric and the second eccentric may be formed integrally. This has the advantage that the size of the pump may be further decreased by integrating the first and second eccentric. A further advantage is, that a readjustment of the first and second eccentric, in particular their position relative to each other, may be avoided, increasing the reliability of the diaphragm pump.

In another preferred embodiment of the invention the second eccentric comprises a roll. The roll may be rotatably attached to the second eccentric, and may comprise a ball bearing. The second eccentric may rotate around the first axis, wherein the roll may rotate around a second axis, wherein the second axis may be arranged in parallel to the first axis, but horizontally spaced apart. The design of the second eccentric comprising a roll has the advantage that due to the rolling movement of the roll a reduction of frictional forces may be achieved .

In a particularly preferred embodiment of the invention the connector rod is frame-like shaped. The connector rod may be connected to the first eccentric and the diaphragm of the diaphragm pump in order to transfer a rotational, eccentric movement of the first eccentric to the diaphragm, in order to actuate the diaphragm with an essentially translational , in particular reciprocating, movement. The frame-like shape of the connector rod may be designed in form of an open frame or a closed frame. The frame-like connector rod designed as an open frame may encompass the pump housing with the diaphragm on one side. The frame-like connector rod designed as a closed frame may surround and/or encompass the first eccentric and the pump housing with the membrane. The diaphragm may be connected to the inside of the frame-like connector rod, in particular of a closed frame. This has the advantage that the size of the diaphragm pump may be further reduced.

Furthermore, in a preferred embodiment of the invention the first and second check valves are connected to a tilting lever for actuating the first and second check valves. The tilting lever for actuating the first and second check valve may tilt around a third axis, wherein the third axis may be designed and arranged in parallel to the first and/or second axis but horizontally spaced apart to these. The tilting lever may be connected to the first and second check valves, actuating the first and second check valve alternating. The tilting lever may exert opening and/or closing forces onto the first and second check valve. The tilting lever may be actuatable by the second eccentric, transferring the rotational, eccentric movement of the second eccentric into a tilting movement of the tilting lever around the third axis, wherein the tilting lever provides essentially a translational opening and/or closing force onto the first and/or second check valve. This has the advantage that the actuating of the first and second check valve may be timed corresponding to the movement of the diaphragm. A further advantage is that the closing force of the first and/or second check valve maybe increased, improving the insensitiveness of the first and/or second check valve to small particles.

In a further preferred embodiment of the invention the first and second check valves are connected to the tilting lever by a positive locking means. The positive locking means may be designed in form of a tongue-and- groove system, wherein the tilting lever may comprise a first and a second gap or slot, which may be arranged vertically, in particular about parallel to the third axis, wherein the first and/or second gap may comprise an opened side enabling an easier assembling of the tongue- and-groove system, in particular by sliding the check valve into the gaps of the tilting lever. The first gap and the second gap of the tilting lever may each form two tongues of the t ongue-and-groove system, wherein the first valve and the second check valve may each comprise an all-round groove into which the tongues of the tilting lever may, in particular loosely, engage. Thus, the tongue-and-groove system forms a positive locking means for opening and/or closing the first and second check valve, by transferring a tilting movement of the tilting lever to the first and second check valve. The positive locking means may also be designed in a way that the tilting lever comprises a first oval opening and a second oval opening into which the all-round grooves of the first and/or second check-valve connect respectively by positive locking. The all-round grooves of the first and second check valve may be arranged at an end of the first and/or second check valve facing the tilting lever. The tilting lever may only contact the first and second check valve when actuating the first and second check valve, for example when opening and/or closing the first and/or second check valve, or holding the first and/or second check valve in an opened position. In a closed position of the first or second check valve the tilting lever may move free and independently from the check valve. Thus, the first and second check valves are loosely guided by the tilting lever with the tongue-and-groove system. This has the advantage that the first and second check valve are only actuated when an opening of the first and second check valve is desired, thus increasing the closing reliability of the check valves while reducing the costs by lowering the required tolerances. The positive locking means comprising the oval shaped openings optimises the positive locking of the tilting lever with the check valves and also the clearance of the check valves, in particular the shafts of the check valves, in a closed position .

In another preferred embodiment of the invention the tilting lever comprises a tilting ring, wherein the tilting ring is actuated by the second eccentric. The tilting lever and the tilting ring may be formed integrally. The tilting ring may be contacted by the second eccentric, in particular by a roll of the second eccentric, wherein the second eccentric may contact the tilting ring on the inside, in particularly the roll of the second eccentric may be moving along the inside of the tilting ring in a rolling motion. The tilting ring allows the rotational, eccentric movement of the second eccentric to be transferred into a tilting movement of the tilting lever around the third axis, thus allowing the actuating of the first and second check valve by the second eccentric. Depending on the shape of the tilting ring, the kinematics of the check valves may be defined, in particular the activation and/or displacement of the check valves around a dead centre of the diaphragm, as well as their respective opening and/or closing time, and also the load acting upon the driving means. In a particularly preferred embodiment of the invention the tilting ring is oval shaped. The oval shape of the tilting ring has the advantage that at a dead centre in the movement of the diaphragm the tilting ring and/or the tilting lever may complete a very fast tilting movement, allowing for a very fast opening and/or closing of the check valves, while at the same time the diaphragm has executed only a minimal displacement movement, thus optimizing the kinematics of the tilting ring, the tilting lever and hence of the first and second check valve. At the same time the load acting upon the driving means is balanced, as the opening and/or closing forces of the check valves are required when the diaphragm executes only a minimal displacement movement around its dead centre, which only executes a minimal load upon the driving means. Thus, the wear of the driving means may be reduced .

Furthermore, in a preferred embodiment of the invention the tilting ring is elastically connected to the tilting lever. The tilting ring may be, in particular in a radial direction, elastically connected to the tilting lever by at least one elastic deformable support. The tilting ring may be elastically deformable and/or displaceable in a direction radial to the third axis, while being designed essentially torsion proof in a direction around the third axis. The at least one elastic deformable support, the tilting ring and the tilting lever may be formed integrally. The elastic connection of the tilting ring to the tilting lever has the advantage that the second eccentric, in particular the roll of the second eccentric, may be essentially continuously in contact with the tilting ring, thus avoiding any noise that may be produced by a reconnection of the eccentric with the tilting ring. Further, production tolerances may be balanced, which may lead to lower manufacturing costs. In a further preferred embodiment of the invention the first check valve and the second check valve are spring biased, in particular with a conical coil spring. The first and second check valve may be spring biased in order to provide a maximum closing force to the first and second, in particular self-closing, check valve. A conical coil spring of the first and second check valve may be arranged in such a way, that the larger diameter of the conical coil spring is arranged in the pump housing, wherein the end of the conical coil spring with a smaller diameter may be contacting the check valve, in particularly at the end of the check valve adjacent to the fluid chamber. The use of a spring biased first and second check valve, in particular with a conical coil spring, has the advantage that the check valves are self- closing, self-aligning and in particular self-centring. This increases the reliable closing of the check valve, in particular due to the guidance of a sealing surface of the first and second check valve, thus reducing wear of the sealing surfaces.

In a most preferred embodiment of the invention a sensor, in particular an optical sensor, is provided for detecting the rotational position of the driving means, in particular of the first eccentric and/or the second eccentric. The sensor, in particular the optical sensor, may be connected to a control unit for driving and/or controlling the diaphragm pump, indicating a rotational position of the first and/or second eccentric to the control unit, enabling the identification of the exact position of the first and/or second eccentric, which enables the detection of the position of the diaphragm and hence if the diaphragm pump is in a suction or pumping cycle. This has the advantage that the dosing capabilities and the accuracy of dosing of the dosing or rather diaphragm pump may be increased, for example by independent cycle speeds, for example a fast suction cycle and a slow pumping cycle. This enables the diaphragm pump to be used for proportional dosing of a fluid, providing an essentially constant flow of the pumped fluid, independent of the position of the diaphragm. Further, this enables a calibration of the diaphragm pump, for example measuring the amount of pumped fluid after a defined number of pumping and/or suction cycles, for example 3.8 pumping cycles for a pumped volume of 3.6 millilitres (ml), allowing for an increase in the precision of the pumped volumes of the diaphragm pump. A further aspect of the present invention is a dosage system comprising at least one diaphragm pump as previously described.

The afore mentioned components, as well as the claimed components and the components to be used in accordance with the invention in the described embodiments, are not subject to any special exceptions with respect to their size, shape, material selection and technical concept such that the selection criteria known in the pursuant field can be applied without a limitation.

DESCRIPTION OF THE FIGURES

Additional details, features, characteristics and advantages of the object of the invention are disclosed in the figures and the following description of the respective figures, which - in exemplary fashion - show one embodiment and an example of a dispensing system according to the invention.

In the drawings:

Fig. 1 shows a sectional side view of a diaphragm pump according to the present invention;

Fig. 2 shows a perspective view of the diaphragm pump in Fig. 1 ;

Fig. 3 shows a partially sectional perspective view of the diaphragm pump according to the present invention; Fig. 4 shows the diaphragm pump of Fig. 3 in a pumping state ;

Fig. 5 shows the diaphragm pump of Fig. 3 at the end of a pumping cycle;

Fig. 6 shows a diaphragm pump in a suction cycle;

Fig. 7a shows a first tilting lever design in a perspective view;

Fig. 7b shows the first tilting lever design in a top view;

Fig. 8a shows a second tilting lever design in a perspective view; and Fig. 8b shows the second tilting lever design in a top view .

The illustration in Fig. 1 shows an embodiment of the present invention. The diaphragm pump 10 comprises a pump housing 12 with a first connector 14 and a second connector (not shown) , wherein the first connector 14 is fluid permeable connected to a fluid chamber 16. The fluid chamber 16 is defined by a wall of the pump housing 12 and a reciprocating movable diaphragm 18. The diaphragm 18 is connected to a connector rod 20, wherein the diaphragm 18 is attached to the connector rod 20 by a screw 22. The connector rod 20 is designed as a closed frame, wherein the connector rod 20 surrounds and encompasses the pump housing 12. The connector rod 20 is connected to a first eccentric 24 for example by a bearing 26. The first eccentric 24 is directly connected to a first axis 28 of a driving means 30. The driving means is designed in form of a stepper motor. A second eccentric 32 is directly connected to the first axis 28 of the driving means 30. The second eccentric 32 comprises a roll 34, wherein the roll 34 is rotatably connected to a second axis 36. The second axis 36 is arranged essentially in parallel to the first axis 28 and horizontally spaced apart. The first eccentric 24 and the second eccentric 32 are formed integrally. When operating the driving means 30, the first eccentric 24 performs a rotational, eccentric movement around the first axis, while the second eccentric 32, in particular the roll 34 of the second eccentric 32, performs a rotational, eccentric movement around the first axis 28, wherein the rotational, eccentric movement of the first eccentric 24 and the second eccentric 32 differ from each other. The roll 34 of the second accentor 32 contacts the inside of a tilting ring 38, wherein the tilting ring 38 is connected to a tilting lever 40, which is connected to a third axis 42. The tilting lever 40 and the tilting ring 38 execute a tilting movement around the third axis 42. The third axis 42 is arranged spaced apart and essentially in parallel to the first axis 28 and/or the second axis 36. The tilting ring 38 and the tilting lever 40 are be integrally formed. The tilting lever 40 is connected to a first check valve 44 allocated to the first connector 14 and a second check valve (not shown) allocated to a second connector (not shown) . In Fig. 2 the arrangement of the first connector 14 with the corresponding first check valve 44 and the second connector 46 with the corresponding second check valve 48 is shown. The first check valve 44 and the second check valve 48 are connected to the tilting lever 40, which is connected to the tilting ring 38 by two elastic deformable supports 50. The tilting lever 40, the supports 50 and the tilting ring 38 are integrally formed and may tilt around the third axis 42. The tilting ring 38 is oval shaped in order to define the deflection and activation of the check valves 44,48 around the dead centre of the movement of the diaphragm 18. During the main movement of the diaphragm 18 the roll 34 moves inside the tilting ring 38 in a circular movement, executing essentially no movement of the tilting lever 40. When the diaphragm 18 is essentially at its dead centre executing essentially no displacement movement, the tilting lever 40 is tilted very quickly, opening and/or closing the check valves 44,48. This has the advantage that the load exerted upon the driving means 30 may be balanced. The roll 34 of the second eccentric 32 contacts the inside of the tilting ring 38. The connector rod 20 is designed as a closed frame shaped connector rod 20 encompassing the pump housing 12 on either side.

In Fig. 3 a diaphragm pump 10 according to the present invention is shown in a perspective view with a partially cross-sectional view of the pump housing 12. Inside the pump housing 12 the diaphragm 18 is defining one movable wall of the fluid chamber 16, wherein the diaphragm 18 is facing away from the driving means 30 and towards the outside of the pump housing 12. Adjacent to the fluid chamber 16 the first check valve 44 and the second check valve 48 are arranged facing towards the driving means 30. The diaphragm pump 10 is shown in a position at the beginning of a pumping cycle, for example with a liquid inside the fluid chamber 16. The first and the second check valve 44, 48 are both in a closed position and are both held in position by a conical coil spring 52, wherein the end of the conical coil spring 52 with the larger diameter is contacting the pump housing 12 and the end of the conical coil spring 52 with the smaller diameter is contacting the check valve 44,48. The conical coil springs 52 exerts a defined closing force onto the first and second check valve 44,48. The first and second check valve 44,48 are essentially loosely connected to the tilting lever 40 by a positive locking means 54 designed as a tongue-and-groove system. The grooves of the tongue-and-groove system are designed as all-round grooves 56 which are arranged on the ends of the first and second check valves 44,48 facing towards the tilting lever 40. The all-round grooves 56 of the first and second check valve 44,48 are arranged in a first gap 58 and a second gap 60, each formed like a slot with an opened and a closed side, of the tilting lever 40. The first gap 58 and the second gap 60 extend essentially in parallel to the third axis 42, wherein the first gap 58 and the second gap 60 form the tongues, in particular two tongues each, of the positive locking means 54 in form of the tongue-and-groove system. The all-round grooves 56 of the first and second check valve 44,48 are loosely engaged and guided by the first gap 58 and the second gap 60, forming the positive locking means 54. In the shown position of the diaphragm pump 10 the first and second check valve 44,48 are loosely guided by the tilting lever 46, in particular the positive locking means 54, wherein no translational opening and/or closing force and no side forces for tilting the first and second check valve 44,48 may be exerted onto the check valves 44, 48 from the tilting lever 40.

In Fig. 4 the diaphragm pump 10 is shown with a first eccentric 24 and a second eccentric 32 comprising a roll 34, both rotated by about 90° compared to the diaphragm pump 10 shown in Fig. 3. By rotating the first and second eccentric 24,32 the closed frame-shaped connector rod 20 has moved inwards towards the tilting lever 40, moving the diaphragm 18 towards the inside of the pump housing 12, reducing the size of the fluid chamber 16 and thus forcing a fluid out of the fluid chamber 16 through the second check valve 48, which is in an opened position. A second check valve 48 is actuated by the tilting lever 40, while at the same time the spring-biased first check valve 44 is closed.. The tilting lever 40 is actuated by the movement of the second eccentric 32, in particularly the roll 34 contacting the inside of the tilting ring 38.

In Fig. 5 the diaphragm pump 10 is shown in a position where nearly all the fluid has been expelled from the fluid chamber 16, by rotating the first and second eccentric 24,32 by about 180° compared to the diaphragm pump 10 in Fig. 3. The tilting lever 40 is in a neutral position, exerting no opening or closing forces onto the first and second check valve 44,48, wherein the first and second check valve 44,48 are closed by the conical coil springs 52. By a further rotation of the first and second eccentric 24,32 by about 90° compared to the diaphragm pump 10 shown in Fig. 3, the diaphragm 18 is moved towards the outside of the pump housing 12 (Fig. 6) by the connector rod 20, thus drawing a fluid into the fluid chamber 16 through the opened first check valve 44. The first check valve 44 is actuated by the tilting lever 40 and moved into an opened position, while at the same time the spring-biased second check valve 48 is closed by the force of its spring. In fig. 7a a first design of the tilting lever 40 is shown. The tilting lever 40 is rotatable mounted around the third axis 42 and comprises in a mounted state a positive locking means 54 designed in form of a tongue- and-groove system. The positive locking means 54 is formed by the first gap 58 and the second 60 and the first and second check valves (not shown) which may be arranged in the first and second gap 58,60, wherein the first and second gap 58,60 form the tongue part, positively interlocking with the all round grooves (not shown) of the first and second check valve. The first and second gap 58,60 are each arranged in an elongated concave recess, running essentially parallel to the third axis 42. The tilting lever 40 comprises two elastic supports 50 connected to the tilting ring 38, which may be designed essentially inflexible, in order to transfer a tilting movement from the tilting ring 38 onto the tilting lever 40. The supports 50 are elastically deformable in a direction essentially radial to the third axis 42 and essentially torsion proof around the third axis 42. This enables the tilting ring 38 to be elastically displaceable in a direction radial to the third axis 42, while being essentially torsion proof in a direction around the third axis 42. The tilting ring 38 may be designed elastically deformable in a direction essentially radial to the third axis 42. This has the advantage that the roll 34 may be in an essentially constant contact with the tilting ring 38 avoiding any clicking noises of the roll 34 reconnecting to the tilting ring 38. A top view of the first tilting lever design is shown in fig. 7b, illustrating the oval shape of the tilting ring 38, wherein the tilting ring 38 is elongated into an oval shape essentially radial to the third axis 42. The tilting ring 38 is connected to the tilting lever 40 by two supports 50.

A second design of the tilting lever 40 is illustrated in fig. 8a. The tilting lever 40 is rotatable mounted around the third axis 42 and comprises in a mounted state a positive locking means 54. The tilting lever 40 comprises a first oval opening 64 and a second oval opening 66 for receiving the all round grooves (not shown) of the first and second check valves (not shown) respectively. The inner diameter of the all round grooves may be smaller than the diameter of the respective oval openings 62,64, while the outer diameter of the grooves may be larger than the diameter of the diameter of the respective oval openings 62,64, thus forming a positive locking means 54 for transferring a tilting movement of the tilting lever 40 onto the first and second check valves. For example, the first check valve may be opened by being pulled in an essentially translational direction by the tilting lever 40 while at the same time the second check valve is free to move independently from the tilting lever 40 and may be closed by its spring. The first and second oval opening 62,64 are each arranged in an elongated concave recess, extending essentially in parallel to the third axis 42. The body of the tilting lever 40 comprises an essentially U-shaped form, wherein the oval openings 62, 64 are arranged at the base of the U-shape. The arms of the U-shaped tilting lever 40 are extending along either side of the tilting ring 38. The tilting ring 38 is connected to the U-shaped tilting lever 40 by several elastic bars 66, in particular two bars 66 on either side of the tilting ring 38. The bars 66 are essentially arranged in parallel in a way to allow a displacement of the tilting ring 38 essentially, in particular only, in a direction radial to the third axis 42. The bars 66 are designed essentially inflexible in a direction around the third axis 42. This has the advantage of ensuring an essentially continuous contact between the roll 34 and the tilting ring 38 avoiding any clicking noises. Further, production tolerances may be balanced. In fig. 8b a top view of the tilting lever 40 shown in fig. 7a is illustrated, displaying the oval shape of the tilting ring 38, wherein the tilting ring 38 is elongated into an oval shape essentially radial to the third axis 42.

The particular combinations of elements and features in the above detailed embodiments are exemplary only; the interchanging and substitution of these teachings with other teachings in this and the patents/applications incorporate by reference are also expressly contemplated. As those skilled in the art will recognize, variations, modifications, and other implementations of what is described herein can occur to those of ordinary skill in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the foregoing description is by the way of example only and is not intending as limiting. In the claims, the wording "comprising" does not exclude other elements or steps, and the identified article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. The inventions scope is defined in the following claims and the equivalents thereto. Furthermore, reference signs used in the description and claims do not limit the scope of the invention as claimed . List of reference signs

10 diaphragm pump

12 pump housing

14 first connector

16 fluid chamber

18 diaphragm

20 connector rod

22 screw

24 first eccentric

26 bearing

28 first axis

30 driving means

32 second eccentric

34 roll

36 second axis

38 tilting ring

40 tilting lever

42 third axis

44 first check valve

46 second connector

48 second check valve

50 support

52 spring

54 positive locking means

56 groove

58 first gap

60 second gap

62 first oval opening

64 second oval opening

66 bar

Claims

1. A diaphragm pump, in particular for use as a

detergent dosage pump, comprising a pump housing (12), wherein the pump housing (12) comprises at least a first connector (14) and a second connector (46), a fluid chamber (16) connected fluid permeable to the at least first connector (14) and second connector (46), a

reciprocating moveable diaphragm (18) defining a wall of the fluid chamber (16), at least a first check valve (44) allocated to the first connector (14) and a second check valve (48) allocated to the second connector (46), a first eccentric (24) and a second eccentric (32), a driving means (30) for actuating the first and second eccentric (24,32), wherein the diaphragm (18) is actuated by the first eccentric (24) by a connector rod (20), and the first check valve (44) and the second check valve (48) are actuated by the second eccentric (32) .

2. The diaphragm pump according to claim 1, wherein the second eccentric (32) is connected to the first eccentric (24) .

3. The diaphragm pump according to any of the preceding claims, wherein the second eccentric (32) comprises a roll (34) .

4. The diaphragm pump according to any of the preceding claims, wherein the connector rod (20) is frame-like shaped.

5. The diaphragm pump according to any of the preceding claims, wherein the first and second check valves (44,48) are connected to a tilting lever (40) for actuating the first and second check valves (44, 48) .

6. The diaphragm pump according to any of the preceding claims, wherein the first and second check valves (44,48) are connected to the tilting lever (40) by a positive locking means (54) .

7. The diaphragm pump according to any of the preceding claims, wherein the tilting lever (40) comprises a tilting ring (38), wherein the tilting ring (38) is actuated by the second eccentric (32) .

8. The diaphragm pump according to any of the preceding claims, wherein the tilting ring (38) is oval shaped.

9. The diaphragm pump according to any of the preceding claims, wherein the tilting ring (38) is elastically connected to the tilting lever (40) .

10. The diaphragm pump according to any of the preceding claims, wherein the first check valve (44) and the second check valve (48) are spring biased, in particular with a conical coil spring (52) .

11. The diaphragm pump according to any of the preceding claims, wherein a sensor, in particular an optical sensor, is provided for detecting the rotational position of the driving means (30), in particular of the first eccentric (24) and/or the second eccentric (32). A dosage system comprising a diaphragm pump ording to claims 1 to 11.