MULTIPLE DIAPHRAGM PUMP

Abstract

Multiple diaphragm pumps are known in the art that are operated by compressed air and in which the valves are controlled by a slide element. The slide element is magnetically actuated without mechanical engagement involved in the actuation. This has the consequence that only a small amount of force can be applied which may not be sufficient due to static friction of the valve seal. The invention presents a hybrid solution which facilitates a mechanical actuation of a valve piston provided for valve control as well as a magnetic overcoming of a dead center that may be reached by the valve piston and the diaphragm piston that actuates the diaphragms of the multiple diaphragm pump.

Claims

1. A multiple diaphragm pump, comprising: a first diaphragm chamber separated by a first diaphragm into a first propellant chamber and a first media chamber; a second diaphragm chamber separated by a second diaphragm into a second propellant chamber and a second media chamber, wherein a diaphragm piston mechanically couples the first diaphragm and the second diaphragm and extends into a switch housing and cooperates with a valve piston to control an inflow and outflow of propellant into and out of the first propellant chamber and the second propellant chamber, wherein a magnet arrangement including a first magnet arrangement and a second magnet arrangement is arranged between the diaphragm piston and the valve piston, wherein the diaphragm piston cooperates mechanically with the valve piston to actuate a valve so that the first magnet arrangement arranged at the valve piston is moved from an idle position in a plane of the second magnet arrangement arranged at the diaphragm piston, wherein the second magnet arrangement is arranged parallel and coaxial to the first magnet arrangement, wherein the valve piston is supported parallel or coaxial to the diaphragm piston, wherein one of the valve piston and the diaphragm piston forms a head piece that is received in a cage formed by another of the valve piston and the diaphragm piston, wherein the head piece forms a head piece contact surface and the cage forms cage contact surface, wherein the head piece contact surface and the cage contact surface face each other, and wherein a clearance is provided between the head piece contact surface and the cage contact surface.

2. The multiple diaphragm pump according to claim 1, wherein the first magnet arrangement is associated with the cage contact surface when the cage is formed at the valve piston and the second magnet arrangement is associated with head piece contact surface when the head piece is formed diaphragm piston, or wherein the first magnet arrangement is associated with the head piece contact surface when the head piece is formed at the valve piston and the second magnet arrangement is associated with cage contact surface when the cage is formed diaphragm piston, and wherein the second magnet arrangement is oriented opposite to the first magnet arrangement.

3. The multiple diaphragm pump according to claim 2, wherein the cage is displaceable in a linear manner between two housing contact surfaces.

4. The multiple diaphragm pump according to claim 3, wherein third magnet arrangements are associated respectively with the two housing contact surfaces, wherein the third magnet arrangements are oriented identical to the first magnet arrangement.

5. The multiple diaphragm pump according to claim 1, wherein the valve piston actuates the valve configured as a 5/2-way valve to control a propellant flow into the propellant chambers.

6. The multiple diaphragm pump according to claim 4, wherein the first magnet arrangement, the second magnet arrangement and the third magnet arrangements are formed respectively from one or plural magnets that are identically oriented and spatially separated.

7. The multiple diaphragm pump according to claim 6, wherein the magnets are permanent magnets or a neodymium magnets configured as ring magnets.

8. The multiple diaphragm pump according to claim 1, wherein the propellant is compressed air.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The invention is now described in more in detail based on an advantageous embodiment with reference to drawing figures, wherein:

[0021] FIG. 1 illustrates a multiple diaphragm pump configured as a double diaphragm pump including a propellant valve which is connected through a switch housing with a diaphragm piston shown in a first switching position;

[0022] FIG. 2 illustrates the double diaphragm pump according to FIG. 1 in a second switching position;

[0023] FIG. 3 illustrates the double diaphragm pump according to FIG. 1 in a third switching position;

[0024] FIG. 4 illustrates the double diaphragm pump according to FIG. 1 in a fourth switching position; and

[0025] FIG. 5 illustrates a connection between the diaphragm piston and a valve piston connected with the valve within the switch housing.

DETAILED DESCRIPTION OF THE INVENTION

[0026] FIG. 1 shows a double diaphragm pump 1 that includes two diaphragm chambers 2 and 6. The diaphragm chambers 2 and 6 are divided by a respective diaphragm 5 and 9 into a propellant chamber 4 and 8 and a media chamber 3 and 7. Compressed air is conducted from a propellant source 16 through a valve arrangement 15 that is configured as a 5/2 way valve into the second propellant chamber 8 in order to move the second diaphragm 9 against the pressure of the medium included in the second media chamber 7 towards the second media chamber 7 and feed the medium from the second media chamber 7. Thus, the second diaphragm 9 is coupled through a diaphragm piston 7 with a first diaphragm 5 so that the second diaphragm moves with the first diaphragm so that the first diaphragm 5 feeds propellant from the first propellant chamber 4 through the valve arrangement 15. This in turn expands the first media chamber 3 and pulls media into the first media chamber 3

[0027] The valve position of the valve arrangement 15 is thus actuated by a valve piston 10 that is mechanically connected with the diaphragm piston 17 as illustrated in FIG. 5.

[0028] FIG. 2 shows the subsequent step where the diaphragms 5 and 9 are displaced in opposite directions wherein clearance and time offset are provided between the diaphragm piston 17 and the valve piston 10 so that the valve arrangement 15 still is in the prior position at this point in time.

[0029] FIG. 3 illustrates the next step where the valve arrangement 15 has switched so that the 5/2-way valve supplies the first propellant chamber 4 with compressed air while the diaphragms 5 and 9 now commence to displace the medium from the first media chamber 3 and the compressed air from the second propellant chamber 8.

[0030] This is completed in FIG. 4 in which the valve arrangement 15 has not switched yet, however the diaphragm valve piston 17 approaches the end position.

[0031] FIG. 5 illustrates the interior of the switch housing 21 that causes the switching, wherein the diaphragm piston 17 protrudes into the switch housing from the left side and valve piston 10 protrudes into the switch housing from the right side. Thus, the free end of the diaphragm piston 17 forms a head piece 19 which is received in a cage 13 at the free end of the valve piston 10. Thus, the headpiece 19 has clearance in the cage 13 similar to a piston in a cylinder so that a movement of the diaphragm piston 17 impacts the movement of the valve piston 10 directly only when the head piece 19 contacts a cage contact surface 14 of the cage 13 with head piece contact surfaces 20 and presses against the contact surface of the cage 13. Due to this mechanical coupling the diaphragm piston 17 can move the valve piston 10 into a switching position where the cage 13 of the valve piston 10 contacts housing contact surfaces 22 of the housing 21. Typically, this position is not reached due to the movement of the diaphragm piston 17 alone, rather the valve piston 10 may stop in a dead center shortly before the switching position where the valve is not in a clear switching position and the membrane piston 17 does not move any further due to the lack of pressure in the membrane chambers 2 and 6. For this case, magnet arrangements 11, 18 and 23 are arranged in the cage 13, the head piece 19 and the housing contact surfaces 22 wherein the magnet arrangements are configured to avoid this dead center.

[0032] Thus, first magnet arrangements 11 are arranged in the cage and third magnet arrangements 23 are arranged in the housing contact surfaces with identical orientations so that they attract each other. The third magnet arrangements can be omitted if necessary but the third magnet arrangements pull the cage 13 magnetically against the housing contact surfaces 22 in an end position of the cage 13 and thus help to overcome the undefined dead center position. An opposite second magnet arrangement 18 urges the cage 13 towards the end position in the end positions since identical poles are oriented towards each other and repel each other. This way a dwelling of the valve piston in the dead center can be prevented due to the attraction of the cage 13 due to the cooperation of the first magnet arrangement 11 and the third magnet arrangement 23 thus also because of the rejection between the second magnet arrangement 18 of the head piece 19 and the first magnet arrangement 11 of the cage 13 toward the housing contact surface 22.

[0033] The diaphragm pump described supra makes more efficient use of the magnet forces due to the distribution of the magnets over both pistons in order to prevent a stand-still of the mufti-diaphragm pump in a common dead center of diaphragm piston and valve piston.

REFERENCE NUMERALS AND DESIGNATIONS

[0034] 1 double diaphragm pump [0035] 2 first diaphragm chamber [0036] 3 first media chamber [0037] 4 first propellant chamber [0038] 5 first diaphragm [0039] 6 second diaphragm chamber [0040] 7 second media chamber [0041] 8 second propellant chamber [0042] 9 second membrane [0043] 10 valve piston [0044] 11 first magnet arrangement [0045] 13 cage [0046] 14 cage contact surface [0047] 15 valve arrangement [0048] 16 propellant source [0049] 17 diaphragm piston [0050] 18 second magnet arrangement [0051] 19 head piece [0052] 20 head piece contact surface [0053] 21 switch housing [0054] 22 housing contact surface [0055] 23 third magnet arrangement