Technical fieldThe invention relates to a suction pump with an exhaust valve as defined in the general concept of claim 1.
State of the artSuction pumps are known for a wide variety of applications, but they are best used in breast pumps to pump breast milk or as drainage pumps to suck out body fluids.
There are suction pumps in closed systems which always circulate the same air in the pump room, but there are also open pump systems with an exhaust valve which can be opened cyclically by an electromagnet.
The requirements for these suction pumps, especially when used as breast pumps, are relatively high, so they should be as powerful as possible and yet relatively small, and, especially when used as breast pumps, they should be as easy to clean and as easy to maintain as possible.
US 4 886 494 shows a suction pump with a membrane plate, which has an inlet and an outlet valve and a vacuum membrane, and a valve seat for an exhaust valve.
US 6 090 065 describes a vacuum pump with a vacuum membrane and a plunger that acts on a membrane plate independent of the vacuum membrane.
Description of the inventionIt is the task of the invention to create a suction pump that can be assembled as easily as possible.
This task is solved by a suction pump with the characteristics of claim 1.
The suction pump according to the invention has an exhaust valve with an exhaust membrane, whereby this exhaust membrane and a vacuum membrane used to generate the vacuum are individually formed into a common membrane plate.
The fact that the exhaust valve and the vacuum membrane are located on the same plate makes these elements more cost-effective to manufacture and easier to install.
In a preferred embodiment, the pump has an upper, middle and lower housing, with a membrane plate or valve plate placed between the housing parts. This division allows several elements to be realized on the same component. In particular, the vacuum membrane necessary for the production of the suppression and the de-ventilation membrane necessary for the removal of the suppression can be produced individually on the same component.
Another advantage of this modular multi-level design is that the pump can be cleaned by simple rinsing without having to be disassembled into its individual parts. Thanks to the exhaust carried outwards, a sponge is unnecessary. Such sponges are used in the state of the art to absorb milk sucked into the pump and also to dampen the sound.
A preferred design of the suction pump allows the pump to be designed as small as possible while still allowing for short pump cycles.
In this preferred embodiment, a vent body closing an exhaust valve vent is first partially raised, requiring less force than if the entire vent were released in one step.
The means used for the operation, especially the lifting of the exhaust, may therefore have a smaller power and may therefore be less trained. If an electromagnet is used as such a means, a relatively low-powered specimen can be used. This is because the electromagnet can apply less force at first when pulling or lifting the exhaust than at the end of the movement.
The pump can easily reach 120 cycles per minute, but it can also be operated optimally at a cycle rate of 50-72 cycles per minute, one of which is particularly suitable for stimulation and the other for expressing breast milk.
In a preferred variant of the above embodiment, only a marginal area of the exhaust is first removed from the exhaust opening, and a minimum force is required if this marginal area coincides with an angle of the exhaust.
The vent body is the membrane. The elevation of its edge area is facilitated if the elevated edge area has a lower thickness than the rest of the membrane. Preferably the vent opening is polygonal, especially square or triangular, formed.
The membrane can be raised by attaching or forming a connecting pin to it, which is attached to an anchor of the magnet. The connecting pin is preferably located in the peripheral area of the membrane covering the vent. However, the membrane can also be formed with a raised flange, whereby the connecting pin is not located above the vent but on that raised flange.
If the connecting pin is designed to move with respect to the membrane, manufacturing or installation tolerances can be overcome. Angle errors of the electromagnet can also be compensated. Good results were achieved with a connecting pin that is individually moulded to a silicone vent membrane and which, due to appropriate material thickening, has sufficient stiffness. It can be rigidly moulded.
The above embodiment with the vent membrane operated in a peripheral area has the advantage of ensuring tightness and thus, in particular when used in a breast pump, of not leaking the pumped milk.
Another advantage of the above embodiments, especially when using the membrane, is that no springs are needed and the number of parts required can be reduced.
In another preferred embodiment, the suction pump has a safety valve, which prevents the suction pump from being inactivated by liquid, especially milk, which has been sucked into the pump and settled there.
This suction pump has a safety valve with a first stage opening at a first low pressure and a second stage opening at a second low pressure, the first low pressure being quantitatively lower than the second.
This two-stage formation of the safety valve prevents milk from reaching the second stage. Since the first stage opens at a very small deviation from the ideal pressure, it will still open at a higher pressure in the event of adhesion, i.e. in an emergency. The second valve prevents the safety valve from opening in its entirety at too small a deviation, but opens reliably in an emergency.
The suction pump according to a preferred embodiment can thus remove the vacuum without excessive force in a relatively short time. The pump according to the invention is suitable for a wide range of applications. In particular, it is suitable as a breast pump for suctioning breast milk and as a drainage pump for suctioning bodily fluids. The pump unit according to the invention is particularly suitable for use in a portable breast pump, as described in particular in WO 2004/069306 (registration number PCT/CH 2004/000061).
Other advantageous embodiments are shown by the dependent claims.
Brief description of the drawingsThe following illustrates the subject-matter of the invention by means of preferred embodiments shown in the accompanying drawings:Figure 1a perspective representation of the suction pump according to the invention without an external housing;Figure 2a view of the suction pump according to Figure 1 from below;Figure 3a longitudinal section of the suction pump according to Figure 1;Figure 4a explosion representation of the suction pump according to Figure 1;Figure 5a perspective representation of a horizontal section of the suction pump according to Figure 1;Figure 6a view of a membrane platform of the suction pump according to Figure 1;Figure 7a view of the membrane platforms according to Figure 7;Figure 10a view of the membrane platforms according to Figure 11;Figure 11a view of the membrane platforms according to Figure 10;Figure 11a view of the membrane platforms according to Figure 10;Figure 11a view of the membrane platforms according to Figure 10;Figure 10a view of the membrane platforms according to Figure 10;Figure 11a view of the membrane platforms according to Figure 10;Figure 10a view of the membrane platforms according to Figure 10;Figure 11a view of the membrane platforms according to Figure 10;Figure 10a view of the membrane platforms according to Figure 10;Figure 11a view of the membrane platforms according to Figure 10a view of the membrane platforms according to Figure 10;Figure 10a view of the membrane platforms according to Figure 11a view of the membrane platforms according to Figure 10;Figure 12a view of the membrane platforms according to Figure 11a view of the surface of the surface of the surface of the suction pump;Figure 11a view of the surface of the surface of the suction pumps;Figure 11a view of the surface of the surface of the suction pumps;Figure 10a view of the surface of the suction pumps;Figure 10a view of the suction pumps;
Ways of carrying out the inventionThe following figure shows a suction pump according to the invention, particularly suitable for a breast pump for the extraction of human breast milk, but also suitable for other applications, e.g. for drainage pumps for the extraction of bodily fluids.
The actual pump unit is shown only, which is usually housed in an outer housing, and the electronics necessary to operate the pump and any energy storage such as a battery or accumulator are not shown.
The pump is extremely compact, one of its main components being an electric motor, and it has an upper, middle and lower housing 2, 4, 6 which can be connected, and a connecting part 7 which is part of these housing parts or, as in this case, is also connected to them.
The connecting part 7 has at least one chest-side connecting rod 70 on which a connecting hose to a chest-cap can be fitted. The connecting part 7 also has an exhaust 71 which also exits from the outer housing. There is also an exhaust pipe 72 and a spacer 73 protruding from the outer housing. The spacers 73 support the pump unit against an outer housing so that no vibrations can be transmitted and adequate sound protection is ensured.
Figure 2 shows how the individual connections 70, 71, 72 are connected to the individual parts of the pump by means of individual channels.
The longitudinal section of the pump, now without engine 1, shown in Figure 3, shows that the pump, despite its compactness, is divided into three clearly distinguishable functional areas: a pump unit P, a ventilation unit V and a safety unit S placed in between. The structure of the pump is best illustrated by the combination of Figures 3 and 4.
The pump unit P has a vacuum membrane 31 and inlet and outlet control valves 51, 52 which, with inlet and outlet openings 62, 63 and with a pump chamber opening 43', connect a pump chamber 43 to a vacuum channel 69. The vacuum membrane 31 is connected to a drive shaft 10 of the electric motor 1 by means of a piston rod 11, a coupling 12, e.g. a ball bearing, and an eccentricity 13 and can be raised and lowered by this motor 1 at a freely selectable rhythm or pump curve according to a given or controlled procedure.
The ventilation unit V has an exhaust valve with an exhaust membrane 32 and an exhaust vent 44 closely closed by this vent. The chamber 44' surrounding the exhaust membrane 44 is connected to the exhaust channel 72 by an exhaust connection 45 and the exhaust membrane 44 is open downwards, i.e. on the side opposite the exhaust membrane 32 and connects to a first exhaust vent 54 of the valve plate 5 and a second exhaust vent 67 of the housing subdivision 6. This second exhaust vent 67 is connected to a safety vent 68 and an opening 68 of the housing subdivision 6 via the vacuum vent 67 and 69 of the housing.
The ventilation membrane 32 is connected by a connecting pin 33 to an anchor 80 of a lift or electromagnet 8. The electromagnet 8 lifts the ventilation membrane 32 and thus releases the ventilation membrane 44. This allows air to pass through the ventilation channel 72 and the first and second ventilation openings 54, 67 into the vacuum channel 69 and the underpressure therein is removed. This raising and lowering of the ventilation membrane 32 is also done by a pre-set or freely selectable control function coordinated with the movement of the ventilation membrane 31.
The safety-belt S has a safety valve which prevents the amount of pressure in the pump from becoming too high and the breast from being injured in the event of a malfunction or failure of the control electronics which coordinate the movement of the vacuum membrane 31 and the exhaust membrane 32.
The safety unit S is designed in two stages according to the invention. The first stage consists of a first safety membrane 55 and a semi-spherical safety valve closure 46 with a small side opening 46', which presses on the first safety membrane 55.
The second stage has a second safety membrane 35 which is closed by means of a control screw 9. Its opening limit can be changed by adjusting the control screw 9. According to the invention it opens at a higher pressure than the first stage, for example at about 290 mmHg.
If milk or other suction fluid enters the pump unwanted, it is deposited in the first stage and cannot pass through the chamber between them to the second stage. It can thus only glue the first safety membrane 55. In the glued state, it may not open at the preset value, but still early enough to allow a discharge. The second membrane only opens when the limit value is actually exceeded and the pump needs to be relaxed. Since the second stage cannot be contaminated, it always opens reliably.
The individual parts of the pump are best seen in Figure 4 which shows that the pump is divided into several levels I, II, III, IV, V, each with parts of the pump unit P, the safety unit S and the exhaust unit V on common levels.
A first level I, which is usually but not necessarily the uppermost level in operation, has the upper housing part 2, the motor 1 mentioned above, and the electromagnets 8. The motor 1 is attached by means of mounting screws 21 to a motor plate 20 of the upper housing part 2. The motor can be screwed to the motor plate 20 and can also be connected to the pump unit. The housing part 2 has a flap chamber 23 which takes in the flap bar 11, the ball bearing 12 connected to it and an excavator with a counter-mass 13. The counter-mass 13 need not be forced forward. The upper part 2 also has a flap chamber 23 mounted in a flap bar 20 which is mounted on its upper end, which is mounted on the bottom of the flap bar 22 which is mounted on the upper part of the flap bar 22 with two electromagnets.
In addition, the second level of the safety valve is equipped with the adjustable adjustment screw 9 in the upper part of the housing 2.
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At the free corner of the first sub-section 32', the connecting pin 33 is moulded, as shown in Figures 7 and 8, at least approximately perpendicular to the membrane plane upwards and is firmly attached to anchor 80; the vent membrane 32 is surrounded by a first seal lip 34.
The membrane plate 3 also includes the vacuum membrane 31 which is connected to the plunger rod 11. The plunger rod 11 may be individually moulded by material thickening on the vacuum membrane 31 or consist of a two-component material. It may also be manufactured separately and connected to the membrane 31 when mounted. The vacuum membrane is sealed by means of a second seal lip 34' to the upper and middle part of the housing 2, 4.
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The third level III is formed by the middle part of the housing 4 which, like the upper and lower part of the housing 2, 6 is preferably made of a solid plastic material, e.g. POM (polyoxymethylene). The middle part of the housing 4 is flat and has a flat top and a flat bottom surface. On its side front surfaces it has upwards and downwards oriented resting clips 40, 41, with the upper 40 clips intervening in the upper one-piece brackets 22 of the upper part 2 and the lower 40 clips intervening in the lower 60 one-piece brackets 6 of the bracketed part. 42 remote fluorescent handles which have 30 holes in the front of the membrane.
In the middle part of the housing 4 there are two downward closed incisions with small side connecting openings. One of these incisions forms the vacuum membrane 43 for the vacuum membrane and thus defines the pump chamber. A second of these incisions forms a first-level safety closure 46. Furthermore, in the middle part of the housing 4 there is chamber 44' with the membrane seat 44 for the defting membrane 32 arranged in it. This seat 44 is triangular in this example.
The fourth layer IV consists of a flexible plate, preferably silicone, formed by a valve plate 5 which also has 50 centrifuges, at least a few of which are connected to the centrifuges of the middle part of the housing 4 and the membrane plate 3.
The valve plate 5 has a first control valve 51 which forms an inlet to the vacuum chamber; it has a second control valve 52 which forms an outlet to the vacuum chamber; from the second control valve 52 a double seal valve 53 leads out, which encloses and seals upward a connection channel 64 located in the lower part of the housing 6 and open upwards.
The valve plate 5 also incorporates the first membrane 55 of the safety valve; the first vent 54 is also present, providing a connection between the vent 44 and a second vent 67 located in the lower part of the housing 6; the individual elements of the valve plate 5 are in turn fitted with lower and upper seal lips to seal against the middle and lower part of the housing 4.6; preferably all the elements of the valve plate 5 are manufactured individually together with this.
The fifth level V comprises the lower part of the housing 6 and the connecting part 7. These two parts may be formed by a single common part or they may be connected by connectors, as shown here.
The lower part of the housing 6 is shown in Figure 4 and in a different perspective in Figure 5. It is also flattened, with its bottom forming the bottom of the pump unit. On the side, the lower inlet brackets 60 are upwards so that the lower inlet pins 41 of the middle part of the housing 4 can be injected into them. There are also centre pins 61 which are also upwards and which can be passed through the center holes 30, 42, 50 of the membrane plate 3, the middle part of the housing 4 and the valve plate 5. These centre pins and centre locks facilitate the stacking of the individual levels and thus allow rapid assembly.
The lower part of the housing 6 also has a first circular aperture with central rise, which forms an inlet 62. A second circular aperture forms an outlet 63. This inlet 62 is connected to the vacuum channel 69 running inside the lower part of the housing 6. This channel 69 first penetrates the safety valve 68 which is also formed as a nozzle and over which the first stage safety membrane 55 is located.
The connecting channel 64, which is open at the top and is sealed through the seal 53 in the lower part of the housing 6, is connected to the outlet 63.As shown in Figure 5, the connection channel 64 ends in an exhaust port 66 which is plugged into the exhaust port 71.
This design allows the pump to be cleaned easily, and if milk or other suction fluid has entered the pump, it can be simply rinsed with water or air by pressing or blowing the cleaning medium through the chest pump side connector 70 and leaving the pump through the exhaust pipe 72 and the exhaust pipe 71.
Figure 9 shows a partial view from the top into the upper part of the housing 2. As can be seen here, the adjustment screw 9 of the safety valve S is formed with a round cross section but screwed into a square thread opening 25 which ensures a sufficient air flow at all times.
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The suction pump according to the invention therefore has several advantages: it offers great functionality in a small space and is also cheap to manufacture and easy to install.
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