WO2003068040A1

WO2003068040A1 - Dosing pump

Info

Publication number: WO2003068040A1
Application number: PCT/CH2003/000095
Authority: WO
Inventors: Markus Ehrensperger
Original assignee: Hts International Trading Ag
Priority date: 2002-02-12
Filing date: 2003-02-07
Publication date: 2003-08-21
Also published as: EP1474023A1; EP1474023B1; AU2003202398A1; ATE299662T1; DE50300816D1; EP1334683A1

Abstract

Dosing pumps which are especially used in soap and foam dispensers have a tendency to create foam. According to the invention, an O-seal (22) arranged in the region of the front side (St) of a plunger pump (18) is guided in an excessively wide ring groove (21) in said plunger pump, in such a way that it can also be axially displaced. Passages are formed by means of additional front-side extensions (34, 35), said passages causing a pressure compensation during the return stroke (RH) of the plunger (18). The resulting return pressure is thus reduced and foam formation affecting the dosage is prevented. A standard additional valve which is activated during the return stroke (RH) is rendered redundant as the O-seal (22) also takes on the function thereof. Said O-seal (22) is located on the rear shoulder of the ring groove (21) during the delivery stroke (PH) and seals in a conventional manner.

Description

metering

The present invention relates to a metering pump for liquid or cream-like soaps according to the preamble of claim 1.

Known soap dispensers (including FR -A- 2 206 493) are based on a dosage of the soap solution, by a pump, which has a slide-like piston and doses the soap in portions from an overhead container, via an intermediate container, and hand wash releases.

The slide, which has a cylindrical cross section, is provided on one long side with a circumferential groove and a sealing ring inserted therein, and is guided in a cylinder closed on one end side. A

Coil spring presses the slide against the actuating direction up to a stop, as a result of which the cylinder space thus formed fills with soap solution via a connection hole to the intermediate container. If the slider is now moved by hand against the spring force using its actuating button, the soap solution in the slider flows through a longitudinal hole, via a groove that is open at the bottom and an outflow channel in the cylinder onto a palm that holds the soap (the hand offered).

If you let go of the actuation button, the spring pushes the slide back into the starting position, which first causes an undesirable inflow of air through the outflow channel and only then a desired inflow of soap solution into the cylinder space. The cylinder room is thus filled with soap solution and air; the subsequent next actuation leads to non-reproducible doses due to foam formation and foam compressions depending on the actuation speed; The dispenser also tends to drip.

This disadvantageous behavior was improved by constructive changes, such as the integration of non-return valves in the soap inflow and in the slide, which both made the dispenser more expensive and, in the event of long interruptions in operation, put the valve body out of operation by sticking the valve bodies to their valve seats.

It is therefore an object of the invention to provide a reliable metering pump which does not have the aforementioned disadvantages and which ensures a reproducible metering of soap solution and cream-like soaps with minimal technical and economic outlay.

In particular, even with strongly foaming media, it should not form a foam cushion in the dosing space and / or storage container. Also on the metering pump or. Actuation forces to be applied to the dispenser, despite existing sealing elements, must be minimal.

The metering pump should also be able to be equipped with an electric drive without major design changes and should also be suitable for contactless battery operation.

This object is solved by the features of claim 1. In the patent claims, a distinction is made between a rear and a front radial sealing element, the front, second sealing element naturally being located in the ejection region of the slide.

It has been shown that even foaming soaps do not tend to foam due to the inventive arrangement of the front sealing element in the metering pump. During the return stroke and in the idle state, pressure equalization takes place between the interior of the pump and the intermediate container. The front sealing element acts as a pressure compensation valve, as it rests in the annular groove on the front shoulder in the return stroke, soap can flow into the metering part of the interior - this is in contrast to conventional slide or piston pumps, which do not or only minimally have displaceable sealing elements and at least displace the air and / or liquid located between the piston body and the cylinder bore during the return stroke into the intermediate or storage container.

The medium is dispensed as in any other slide pump; the sealing element lies on the rear shoulder of the annular groove during the working stroke and seals the slide in a conventional manner with respect to the cylinder space. The first sealing element is during the entire dosing process, i.e. tight during the return stroke (filling process) and the working stroke (discharge).

A spring in the outflow channel that acts on the check valve only has to overcome the static pressure of the liquid and the mass of the valve body (plastic ball). Due to the hardly existing negative pressure during the filling process, the valve body is only slightly loaded, which its service life and thus the operational safety increased considerably.

A dispenser realized according to the teaching of claim 1 shows a higher dosing accuracy than conventional dosing pumps, since no foaming takes place in the cylinder space. Due to the lower fluid dynamic friction, it also requires less energy to operate.This has a particularly positive effect on battery-powered, contactless dispensers.

Advantageous developments of the subject matter of the invention are described in the following dependent claims:

The peripheral grooves in the front of the slide, which form a connection to the dosing chamber with the ring-shaped second groove, can also improve the pressure compensation on the slide.

If two upper and two lower peripheral grooves are inserted vertically on the ring-shaped second groove, the flow is improved and the frictional resistance is reduced again.- Alternatively, other connections to achieve a flow can be realized, such as a conical or stepped running second groove.

A concave recess on the front of the slide prevents it from striking the bottom of the cylinder chamber; the medium displaced into this recess acts as a hydraulic spring and reduces the force to be applied for the return stroke. It is particularly advantageous after very long interruptions in operation if the check valve is detachably arranged at the end of the outflow channel and its valve cap also contains the outlet nozzle of the outflow channel. This allows easy cleaning and, if necessary, flushing the entire device with water.

The slide preferably contains a blind hole-like rear center hole with a clutch spring (leaf spring). This makes coupling pins easy to connect, which, among other things. allows the use of the same slide in different dispensers with differently designed drives.

The use of a round seal, also known as an O-ring, is particularly economical for solving the problem, since it is commercially available and is also an excellent one

Has rolling behavior for the displacement within the width of the annular groove.

In contrast to a conventional valve, this O-ring, which rolls with the slide movement, loosens axially from its seat even after the dispenser has been out of operation for a long time, so that the notoriously known sticking is eliminated and soap solution can be dispensed again at any time.

The front groove has proven itself, groove widths larger than 1.5 times the diameter of the O-ring.

A flow-optimized dispenser with minimal power requirements guides the soap solution through a hole that protrudes from the end of the valve in the idle state and in the area of the second annular groove. - This causes the metering pump to be automatically vented.

A practical embodiment of a metering pump installed in a soap dispenser is explained in more detail below with reference to drawings. Show it:

1 shows a manually operable soap dispenser, only the soap outlet being visible from its metering pump,

2 shows a sectional view through a soap storage container, an intermediate container and a metering pump connected to it,

3 is a perspective view of the slide of the metering pump with inserted coupling pin,

4 is a frontal plan view of the slide in FIG. 3,

Fig. 5 shows a longitudinal section through the arrangement of Fig. 3, through the center and

Fig. 6 shows a further longitudinal section through the arrangement of Fig. 3, but in a section upstream of Fig. 5.

In Figure 1, 1 denotes a soap dispenser, which in the usual way has a housing 2 and from whose underside an annular actuating lever 3 protrudes. A soap outlet 4 is located in front of the actuating lever 3. A transparent viewing window 5 is embedded in the front of the housing 2, behind which there is a color-coded one Level indicator 6 is located. The direction of actuation PH is shown by an arrow.

The sectional view in FIG. 2 shows a soap storage container 7 with an attached intermediate container 8, which has cover-shaped cover surfaces 8 '. In the intermediate container 8, a push-on and push-on part 9 protrudes, which accommodates a soap bottle V arranged overhead. In the lower area of part 9 there is a soap solution passage 10, whereby the level N of the soap solution S in the container 7 is set when the soap bottle V is full. The necessary connection to the outside air is created by a compensating hole 40 in the cover surface 8 '.

On the side shown in FIG. 2 there is a channel 11, which forms the lateral guide for a fill level indicator 6, not shown here. Furthermore, a centering surface 12 is visible in this channel 11, which projects upwards and forms the central guide for the fill level indicator 6, FIG. 1. In the lower front area of the container 7, a cylindrical soap solution supply 13 is provided, which opens with a central bore 14 in the cylinder of a metering pump 15. The interior of the pump 15 has a cylindrical metering space 17, which in turn is connected to a soap outlet 16 and which is closed off by a valve ball 25 mounted in a valve seat 26. The valve ball 25 is acted upon by a spring 27 which is centered in a pressed-on valve cap 24 and which has a central outlet nozzle 28. A vertically arranged reinforcing rib 37 is located in the axis of symmetry of the arrangement in FIG. 2; likewise a cylindrical support 39 for the longitudinal guidance of the drive and coupling means.

In the metering chamber 17 there is an axially displaceable piston 18 which acts as a slide known per se.

In the rear part of this cylindrical slide 18, a notoriously known annular groove 19 with an equally round seal 20, a commercially available O-ring, is embedded and seals the metering chamber 17 of the metering pump 15 from its outside area.

In the front area of the slider 18 there is a further annular groove 21, which is widened compared to the usual annular groove 19. The round seal 22 located in the annular groove 21 is identical to the round seal 20.

It can also be seen that the slide 18 contains a bore 36 and has a central, concave recess 23 on its end face St.

A tubular coupling pin 29 is inserted into the bore 36, and a coupling spring 30 arranged at the end of the slide 18 engages in the opposite longitudinal grooves 30 'thereof. This spring 30 serves at the same time as an end stop for the return stroke RH and prevents inadvertent movement out of the cylinder space 17.

At the rear end of the coupling pin 29, an actuating piece 31 is inserted in its bore 41, which has a lateral recesses 32 and 33 and a coupling nose 38; the coupling nose 38 is engaged in the recess 33. This coupling pin 29 is for a manual hurry operating lever - not shown - provided and is designed according to the respective drive means and adapted to this; the same applies to the coupling piece 29. This allows a single slide 18 to be used for any type of mechanical drive.

According to FIG. 3, peripheral grooves 34 and 35 are let into the end face St of the slide 18, which are guided up to the rear wall of the annular groove 21. In addition, various cutouts 18 'can be seen on the slide 18, which are production-related and also lead to material savings.

4 shows the upper grooves 34 arranged symmetrically to the center and the similar lower grooves 35; cut lines A - A and B - B are also shown.

The two sectional representations FIG. 5 and FIG. 6 show the corresponding longitudinal sections A - A and B - B, the section B - B, FIG. 5, being led through the longitudinal axis of the arrangement formed by slide 18 and coupling pin 29. - The functionally necessary annular gap in the widened annular groove 21 is designated RS.

The dosing pump according to FIG. 2 shows surprising effects:

If one starts from the starting position shown in FIG. 2, it can be seen that the metering space 17 and the connected soap outlet 16 (statically) fill with soap solution S. If the piston 18 is now moved in the actuation direction PH, the O-ring 22 rolls against the rear shoulder of the annular groove 21 and seals the piston 18 with respect to the sierraum 17. There is a pump stroke PH which lifts the valve ball 25 from its seat 26; the soap solution emerges in the form of a jet through the bore 28 and can soap the hand presented.

During the return stroke RH, which is, for example, spring-loaded, the O-ring 22 rolls onto the front shoulder of the annular groove 21. The soap solution can flow in via the annular gap RS formed in this way and the peripheral grooves 34 and 35 (FIG. 3), whereby through the adjusting vacuum, the valve ball 25 is sealingly in its valve seat 26. The pressure equalization established via the annular groove 21 and the grooves 34 and 35 prevents that in others. Slider pumps foam and reduces the necessary actuating force considerably.

In contrast to conventional slide pumps, this takes place without an additional check valve, with a minimal hysteresis and results in a more precise and reproducible dosing volume compared to this.

The recess 23 recessed in the end face of the slide 18 also has a favorable effect, since it acts as a kind of hydraulic spring, since on the one hand it dampens the slide 18 in the pumping stroke PH when it hits the bottom of the metering chamber 17 and on the other - at a minimum enclosed soap solution - the breakaway torque of the slide 18 on the return stroke RH is reduced.

As a result, not only one valve is saved; the pump housing can at the same time be integrally formed with the container part, as the sectional view in FIG. 2 shows impressively. In practice, it has been shown that even with intensive use of the dispenser, no unwanted soap foam is formed and that the dispenser is immediately ready for use even after long interruptions, since no check valves that only adjust to the negative pressure are necessary.

The subject of the invention is of course not limited to soap dispensers; it can also be used, for example, for dosing pumps in foam dispensers.

The actuation force reduced by the subject matter of the invention offers this for installation in battery-powered devices. The uninterrupted service life of non-contact soap and foam dispensers can be extended considerably with the use of weaker drives, which increases the operational readiness of foam and soap dispensers installed there in particular in irregularly used public washrooms and at the same time reduces their maintenance costs.

The entire arrangement can be produced very economically by known die-casting processes using inexpensive polymer materials.

Claims

Patent claims

1. Dosing pump, in particular for foaming media, such as soap solutions and flowable soaps, with a pump containing a cylindrical slide, which is fed with soap via an intermediate container and a storage container placed thereon, and wherein the slide guided in a cylinder space is radially sealed , characterized in that a check valve (24-26) is provided only in the outflow channel (16, 28), that the slide (18) has a rear radial sealing element (20) guided in a first annular groove (19) and a in a second front, axially displaceable sealing element (22) which is guided relative to the first, wider, annular groove (21) and that between the rear, lateral contact surface of this sealing element (22) and the end face (St) of the slide (18) in the return stroke (RH) of the slide (18) there is provided an effective liquid connection (34; 35) for pressure equalization to the metering chamber (17) is.

2. Dispenser according to claim 1, characterized in that in the end face (St) of the slide (18) peripheral grooves (34,35) are embedded, which form a connection to the dosing space (17) with the annular second groove (21).

3. Dispenser according to claim 2, characterized in that two upper and two lower peripheral grooves (34; 35) are provided in the vertical direction.

4. Dispenser according to claim 1, characterized in that the end face (St) of the slide (18) has a concave recess (23).

5. Dispenser according to claim 1, characterized in that the check valve (24-26) at the end of the outflow channel (16) is detachably arranged and that its cap (24) contains the outlet nozzle (28) of the outflow channel (16).

6. Dispenser according to claim 1, characterized in that the slide (18) has a blind hole-like centering hole

(36) and a coupling spring (30), via which a coupling pin (29) can be connected.

7. Dispenser according to claims 1 and 6, characterized in that the storage container (7), its connecting line (13) with the supply for the flowable soap, the housing of the metering pump (15) with the piston guide and the guide for the Coupling pin (29) and the soap outlet (16) are integrally formed.

8. Dispenser according to claim 1, characterized in that at least the second, front seal (22) is a round seal.

9. Dispenser according to claim 8, characterized in that the groove (21) of the round seal (22) has a width which corresponds to at least 1.5 times the diameter of the round seal (22).

0. Dispenser according to claim 1, characterized in that the supply of the flowable soap solution takes place via a bore (14) projecting beyond the end face (St) of the slide (18) and in the region of the second annular groove (21).