DOSAGE PUMP WITH LOW ENERGY CONSUMPTION

Abstract

It is provided a dosage pump (10) comprising a pump housing (12), a first valve (18), a second valve (20), an actuation lever (22), wherein the actuating lever (22) is adapted to be tilted around a tilting axis (24), a disc (34) for providing a torque, wherein the disc (34) is adapted to rotate around an input axis, a first cam (26) connected to the disc (34) and a second cam (30) connected to the disc (34), wherein the actuating lever (22) comprises a first raceway (28), wherein the first raceway (28) and the second raceway (32) are formed such that at least partially during an angle of rotation of the disc (34), where the actuation lever (22) has to apply an actuation force for opening and/or closing the first valve (18) and/or the second valve (20), the first cam (26) or the second cam (30), whose contact point to its corresponding raceway (28, 32) is farer away from the tilting axis (24) of the actuation lever (22) and/or adjusted to a lower torque at the actual angle of rotation of the disc (34), provides the tilting force onto the actuation lever (22). Due to the at least two cams (26, 30) the actuation force at the valves (18, 20) can be provided by means of the cam (26, 30) with a large lever arm, so that a lower torque of the disc (34) is sufficient, which can be generated with a lower energy consumption.

Claims

1. A dosage pump, comprising a pump housing, a first valve for discharging a fluid, a second valve for feeding the fluid, an actuation lever for actuating the first valve as well as the second valve, wherein the actuating lever is adapted to be tilted around a tilting axis with respect to the pump housing, a rotatable disc for providing a torque generated in a motor connectable to the disc, wherein the disc is adapted to rotate around an input axis of rotation, a first cam connected to the disc and a second cam connected to the disc, wherein the actuating lever comprises a first raceway for bearing a first tilting force for tilting the actuation lever provided by the first cam at a first contact point and a second raceway for bearing a second tilting force for tilting the actuation lever provided by the second cam at a second contact point, wherein the first raceway and the second raceway are formed such that at least partially during an angle of rotation of the disc, where the actuation lever has to apply an actuation force for opening and/or closing the first valve and/or the second valve, the first cam or the second cam, whose contact point to its corresponding raceway is farer away from the tilting axis of the actuation lever and/or adjusted to a lower torque at the actual angle of rotation of the disc, provides the tilting force onto the actuation lever.

2. The dosage pump of claim 1 wherein the first raceway and the second raceway are formed such that at least partially during an angle of rotation of the disc, where the actuation lever has to apply no actuation force, the first cam and the second cam are positioned both in an area between the input axis and the tilting axis or the second cam is positioned both outside the area between the input axis and the tilting axis.

3. The dosage pump of claim 1 wherein the first raceway and the second raceway are formed such, that either the first cam or the second cam only provides the first tilting force or the second tilting force respectively at the actuation lever.

4. The dosage pump of claim 1 wherein the first cam is rotatably connected to the disc and adapted to rotate around a first axis of rotation, wherein the first axis of rotation is aligned mainly in parallel and offset to the input axis of rotation, wherein the second cam is rotatably connected to the disc and adapted to rotate around a second axis of rotation, wherein the second axis of rotation is aligned mainly in parallel and offset to the input axis of rotation.

5. The dosage pump of claim 4 wherein the first cam and/or the second cam is designed as a rotatable roller adapted to roll along the respective first raceway or second raceway.

6. The dosage pump of claim 4 wherein the input axis of the disc and the tilting axis of the actuation lever are arranged on a middle line, wherein the first axis of rotation of the first cam and the second axis of rotation of the second cam are arranged on a cam line, wherein the first raceway and the second raceway are formed such that the presence of the first tilting force provided by the first cam at the first raceway and the second tilting force provided by the second cam at the second raceway changes when the cam line is aligned mainly in parallel to the middle line during the rotation of the disc or inclined to a parallel alignment to the middle line by an angle of maximum 60 during the rotation of the disc.

7. The dosage pump of claim 4 wherein the first axis of rotation of the first cam and the second axis of rotation of the second cam are spaced in circumferential direction with respect to each other by mainly 9030.

8. The dosage pump of claim 4 wherein the first axis of rotation of the first cam and the second axis of rotation of the second cam are positioned at mainly the same radial distance to the input axis of the di sc.

9. The dosage pump of claim 1 wherein the first raceway and the second raceway are positioned at different heights with respect to an axial direction of the input axis.

10. The dosage pump of claim 1 wherein the first cam and the second cam are positioned at different heights with respect to an axial direction of the input axis, wherein the first cam overlaps the second raceway at a part of the angle of rotation of the disc and/or the second cam overlaps the first raceway at another part of the angle of rotation of the disc when viewed in an axial direction of the disc.

11. The dosage pump of claim 1 wherein the actuation lever comprises a hollow frame, wherein the first raceway and the second raceway are formed at an inside of the frame.

12. The dosage pump of claim 1 wherein the input axis of the disc and the tilting axis of the actuation lever are arranged on a middle line, wherein the first valve and the second valve are positioned on different sides with respect to the middle line.

13. The dosage pump of claim 1 wherein the first valve and/or the second valve is configured to provide a reset force, wherein the reset force counteracts the actuation force of the actuating lever.

14. The dosage pump of claim 1 wherein the disc is connected to a slidable pusher, wherein the pusher is configured to move back and forth in dependence of the angle of rotation of the disc, wherein the pusher is configured to move a reciprocating diaphragm bordering a fluid chamber for pumping the fluid, wherein the pusher is positioned offset in an axial direction of the input axis with respect to the first cam and the second cam.

15. The dosage pump of claim 1 wherein the disc is connected to a motor, wherein a maximum torque M.sub.max provided by the motor is set with respect to a maximum torque M(.sub.max) for tilting the actuation lever at a specific angle of rotation .sub.max of the disc such that 75%M(.sub.max)/M.sub.max100%.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0031] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter, wherein the described features can constitute each solely or in combination an independent aspect of the invention. In the drawings:

[0032] FIG. 1: is a schematic view of a part of a dosage pump,

[0033] FIG. 2: is a schematic top view of the dosage pump of FIG. 1,

[0034] FIG. 3: is schematic sectional top view of the dosage pump of FIG. 2 along a deeper sectional plane,

[0035] FIG. 4: is a schematic top view of the dosage pump of FIG. 1 after a rotation of a disc by 45 with respect to the dosage pump of FIG. 2,

[0036] FIG. 5: is a schematic top view of the dosage pump of FIG. 1 after a further rotation of the disc by 45 with respect to the dosage pump of FIG. 4,

[0037] FIG. 6: is a schematic top view of the dosage pump of FIG. 1 after a further rotation of the disc by 45 with respect to the dosage pump of FIG. 5,

[0038] FIG. 7: is schematic sectional top view of the dosage pump of FIG. 6 along a deeper sectional plane,

[0039] FIG. 8: is a schematic top view of the dosage pump of FIG. 1 after a further rotation of the disc by 45 with respect to the dosage pump of FIG. 6,

[0040] FIG. 9: is a schematic top view of the dosage pump of FIG. 1 after a further rotation of the disc by 45 with respect to the dosage pump of FIG. 8,

[0041] FIG. 10: is a schematic top view of the dosage pump of FIG. 1 after a further rotation of the disc by 45 with respect to the dosage pump of FIG. 9,

[0042] FIG. 11: is a schematic top view of the dosage pump of FIG. 1 after a further rotation of the disc by 45 with respect to the dosage pump of FIG. 10 and

[0043] FIG. 12: is schematic sectional top view of the dosage pump of FIG. 11 along a deeper sectional plane.

DETAILED DESCRIPTION

[0044] The dosage pump 10 as illustrated in FIG. 1 could be used in a washing machine, dish washer or the like. The dosage pump 10 comprises a pump housing 12, which could be closed by means of not illustrated cover lid. An outlet 14 and an inlet 16 are mounted to the pump housing 12 for dispensing a fluid pumped by the dosage pump 10. The inlet 14 can be opened and closed by means of a first valve 18, wherein the outlet 16 can be opened and closed by means of a second valve 20. The first valve 18 and the second valve 20 can be designed as a spring-loaded normally closed check valve. The first valve 18 and the second valve 20 can be fixed to the pump housing 12 so that occurring forces of the first valve 18 and the second valve 20 can be supported by the pump housing 12.

[0045] The first valve 18 and the second valve 20 can be actuated by means of an actuation lever 22 which can be tilted around a tilting axis 24 over a limited swivel angle. When the actuation lever 22 tildes in a first circumferential direction, a valve stem of the first valve 18 can be moved or a valve stem of the second valve 20 can be moved against a spring force of a reset spring of the corresponding valve 18, 20 for opening the valve 18, 20. When the actuation lever 22 tildes in an opposite second circumferential direction, the other valve 20, 18 can be actuated against a spring force of a reset spring of the corresponding valve 20, 18 for opening the valve 20, 18. In the illustrated embodiment, the respective valve 18, 20 can be actuated by the actuation lever 22 by pulling the valve stem of the corresponding valve 18, 20.

[0046] The actuation lever 22 can be tilted by means of a first cam 26 applying a first tilting force at a first raceway 28 of the actuation lever 22 or by means of a second cam 30 applying a second tilting force at a second raceway 32 of the actuation lever 22. The first raceway 28 and the second raceway 32 are provided at the inside of the frame-like designed hollow actuation lever 22. The first cam 26 and the second cam 30 can be connected to a disc 34 which can be rotated around an input axis 36. The disc 34 can be driven by a synchronous motor for providing a torque. The first cam 26 and the second cam 30 can be rotatably connected to the disc 34 and may rotated around respective rotation axis which are located at mainly the same radius with respect to the input axis 36 and spaced to each other in circumferential direction with respect to the input axis 36 by mainly 90. The first cam 26 and the second cam 30 can be designed like a roller or a bearing. The first cam 26 and the second cam 30 are positioned at different heights in axial direction of the input axis 36 so that the first cam 26 and the second cam 30 cannot disturb each other. Correspondingly the first raceway 28 and the second raceway 32 are positioned at different heights in axial direction of the input axis 36 so that the first raceway 28 and the second raceway 32 cannot disturb each other.

[0047] The input axis 36 of the disc 34 and the tilting axis 24 of the actuation lever 22 are positioned on a middle line 38. The first valve 18 and the second valve 20 are arrange at different sides of the middle line 38, particularly spaced to the middle line 38 by the same distance. The first valve 18 can be maximum opened at the maximum swivel angle of the actuation lever 22 in the first circumferential direction, wherein the second valve 20 can be maximum opened at the maximum swivel angle of the actuation lever 22 in the second circumferential direction, particularly by the same amount.

[0048] By means of the at least two cams 26, 30 and the specific forming of the first raceway 28 and the second raceway 32 the applied tilting force onto the actuation lever 22 can be provided by the cam 26, 30 with the larger lever arm with respect to the tilting axis 24 so that a low torque of the disc 34 provided by a small synchronous motor with a low energy consumption is sufficient for providing a high enough actuation force at the respective valve 18, 20 for overcoming the present reset force and opening the respective valve 18, 20.

[0049] When the disc 34 is rotated in its 0-position as illustrated in FIG. 2 and FIG. 3, the rotation axis of the first cam 26 and the second cam 30 are arranged on a cam line 40 which is arranged far away from the tilting axis 24 and perpendicular to the middle line 38. The first cam 26 starts to provide the first tilting force onto the first raceway 28 of the tilting lever 22 for tilting the actuation lever 22 in the first circumferential direction.

[0050] When the disc 34 is rotated in its 45-position as illustrated in FIG. 4, the second cam 30 is positioned significantly spaced to its second raceway 32 of the actuation lever 22. The whole torque introduced by the disc 34 can be used for providing the first tilting force.

[0051] When the disc 34 is rotated in its 90-position as illustrated in FIG. 5, the cam line 40 is arranged in parallel to the middle line 38. The lever arm of the first cam 26 of a first contact point between the first cam 26 and the first raceway 28 to the tilting axis 24 is quite short and could not be sufficient for providing an actuation force at the second valve 20 for overcoming its reset force and opening the second valve 20. In this situation, the second cam 30 comes into contact with its second raceway 2 of the actuation lever 22. Since the lever arm of a second contact point between the second cam 30 and the second raceway 32 to the tilting axis 24 is larger than provided by the first cam 26 the second tilting force provided by the second cam 30 leads to a higher actuation force at the second valve 20.

[0052] When the disc 34 is rotated in its 135-position as illustrated in FIG. 6 and FIG. 7, the first cam 26 is lifted from its first raceway 28 of the actuation lever 22.

[0053] When the disc 34 is rotated in its 180-position as illustrated in FIG. 8, both the lever arm provided by the first cam 26 and the lever arm provided by the second cam 30 are short. Since the actuation lever 22 shall be tilted in the second circumferential direction and the second valve 20 shall be closed, an actuation force high enough for opening the second valve 20 is not necessary anymore. In fact, a low actuation force provided by the cams 26, 30 enables a tilting of the actuation lever 22 into the second circumferential direction around the tilting axis 24 by means of the reset force of the reset spring inside the second valve 20.

[0054] When the disc 34 is rotated in its 225-position as illustrated in FIG. 9, the reset force of the second valve 20 may not be sufficient anymore for tilting the actuation lever 22 in the second circumferential direction for actuating the first valve 18 so that the first cam 26 take over the function of providing the tilting force onto the actuation lever 22. In this situation, the lever arm provided by the first cam 26 is large enough again for tilting the actuation lever 22 against the reset force of the first valve 18 into the second circumferential direction.

[0055] When the disc 34 is rotated in its 270-position as illustrated in FIG. 10, the second cam 30 may be lifted from its second raceway 32 of the actuation lever 22.

[0056] When the disc 34 is rotated in its 315-position as illustrated in FIG. 11 and FIG. 12, the first valve 18 shall by closed and the actuation lever 22 tilted back into the first circumferential direction, wherein the first valve 18 can be kept open until the disc 34 is rotated in its 360-position, when the pumping cycle starts again. In this situation, the reset force of the first valve 18 may press the actuation lever 22 against the second cam 30, while the first cam 26 may be lifted from the first raceway 20 of the actuation lever 22.