DE9321517U1 - Liquid dispenser - Google Patents

Description

Utility model application

HYGIENE TECHNOLOGY INC. 4743 Christie Drive

Beamsville

OntarioLOR IBO

CANADA

Liquid dispenser
The innovation concerns a liquid dispenser containing

(a) a liquid container, and

(b) one-way valve means connected to the fluid container.
20

Many pump arrangements are known by which liquids such as liquid soap can be withdrawn from liquid containers, whereby the containers can be interchangeable. When using such interchangeable containers, difficulties sometimes arise in withdrawing liquid from the container, especially with viscous liquids such as liquid soap and with containers which are provided with a pump arrangement for withdrawing liquid from the container. For example, liquid does not always come out of the container with every pump movement. When using the liquid dispenser for the first time, a few pump movements must be carried out before liquid comes out of the liquid container.

The innovation is based on the task of avoiding these difficulties when removing viscous liquids.

According to the innovation, this task is solved by
5

(c) evacuation means are provided on the outlet side of the one-way valve means, by means of which gas or air can be sucked out of the liquid container through the one-way valve means.

It has been shown that the difficulties mentioned above are due to the presence of a gas such as air in the container. The basic idea behind the innovation is therefore to design the liquid container in such a way that this gas can be sucked out by means of a negative pressure.

In one embodiment of the innovation, the evacuation means have a cover part, through which the one-way valve means can be covered and which has an opening. When using the liquid dispenser, the liquid container is first filled with liquid. Then the air is removed from the liquid container by applying a negative pressure. The negative pressure is applied to the opening of the cover part.

0 and thereby acts on the one-way valve means.

Preferably, the one-way valve means are designed in such a way that they only allow a gas and/or liquid flow past the one-way valve means from the liquid container to the outside. It is advantageous if the one-way valve means only allow a gas or air transport past the one-way valve means from the liquid container to the outside if there is a negative pressure at the one-way valve means that is further below the atmospheric pressure than a first negative pressure, and only allow a liquid transport past the one-way valve means from the liquid container to the outside if

0 if there is a negative pressure on the one-way valve means which is further below the

atmospheric pressure as a second negative pressure, wherein the second negative pressure

further below atmospheric pressure than the first negative pressure. This means that a certain negative pressure can be applied to the one-way valve means, through which gas or air is sucked out of the container, but not liquid. When all the air has been sucked out of the liquid container, the liquid comes into contact with the one-way valve means. Now, however, the negative pressure applied is smaller than the negative pressure required to suck the liquid past the one-way valve means, so that the liquid is not sucked out.

Embodiments of the innovation are the subject of the subclaims.
10

Examples of implementation of the innovation are explained in more detail below with reference to the associated drawings.

Fig. 1 is a partially broken side view of a first embodiment

a liquid dispenser with a liquid container and a

Pump arrangement.

Fig. 2 is a side view of the liquid dispenser and pump assembly

of Fig. 1, partly in cross section, with the piston in a 0 fully extended position.

Fig. 3 is a side view of the liquid dispenser and pump assembly

of Fig. 1, partially in cross section, with the piston in a fully retracted position.
25

Fig. 4 is a perspective view showing the piston of Fig. 1.

Fig. 5 is a side view showing a second embodiment of a

Liquid dispenser in cross section.

Fig. 6 is a side view showing a third embodiment of a

Liquid dispenser in cross section.

Fig. 7 is an enlarged side view of an embodiment of a

Liquid dispenser in cross section with a cover for use

when evacuating the liquid container.

Fig. 8 is a side view showing a fixed container

connected piston chamber forming body, partly in cross section.

In Fig. 1 to 3, 10 indicates a pump assembly. The pump assembly 10 contains two basic parts, namely a chamber part 12, which forms a piston chamber and a piston 16. The chamber part 12 essentially has a stepped, cylindrical chamber 18 with an outer, cylindrical chamber 202 and an inner, cylindrical chamber 204. The inner chamber 204 has a smaller diameter than the outer chamber 202. Each chamber 202 and 204 has a cylindrical chamber wall, an inner end and an outer end. The outer chamber 202 and the inner chamber 204 are arranged coaxially with each other. The outer and inner chambers 202 and 204 are located axially next to each other, with the outer end of the inner chamber 204 being open towards the inner end of the outer chamber 202. An annular shoulder 206 is formed between the inner end of the outer chamber 202 and the outer end of the inner chamber 204.

The piston 16 is arranged to slide axially in the chamber 18 and can be moved back and forth inwards and outwards through an open end 22 of the chamber 18. In the pump arrangement shown in Fig. 1 to 3, the chamber part 12 not only carries the piston 16, but the chamber part 12 is also attached to a reservoir or container 26, which can be a foldable or non-foldable container. The container 26 is attached via an internal thread 130 to an outer, cylindrical part 40, the internal thread 130 cooperating with a threaded collar 34 of the container 26. When the pump arrangement 10 is connected to the container 26

connected, gas or liquid can be pumped out of the container 26 through the piston 16 by a reciprocating movement of the piston 16.

The chamber part 12 has a generally cylindrical cross-section and is symmetrical about its central axis. The chambers 202 and 204 are located within the chamber 18. The outer, cylindrical part 40 is connected to the chamber 18 by an annular wall 208. The wall 208 is provided with circumferential grooves 210 in which a cover part can be received which corresponds to the cover part 142 shown in Fig. 7 and described later. In the cross-sectional view of the chamber part 12 shown in Figs. 2 and 3, one of several thin, radially outwardly extending reinforcing flanges 212 is shown which support the inner chamber 204.

As can be seen from Figures 3 and 4, the piston 16 has a generally cylindrical cross-section and is slidably received within the chamber 18. The piston 16 is a unitary member and is made entirely of plastic, preferably by injection molding. The piston 16 has a central hollow stem 46 which extends about the longitudinal central axis of the piston 16.

0 The piston 16 has an inner, cylindrical extension 214 of the stem 46, which

at its inner end carries an annular, inner, flexible disk 216. The inner extension 214 and the inner, flexible disk 216 are received in the inner chamber 204. The inner, flexible disk 216 is annular and extends radially outward from the stem extension 214 and has an elastically deformable edge part, 5 which rests with its circumference on the chamber wall of the inner chamber 204.

A circular, resilient, flexible disk 48 having a resiliently deformable edge is located near the inner end of the piston and extends radially therefrom. The flexible disk 48 is located on the piston 16 outside of the inner, flexible disk 216 and is received in the outer chamber 202. The outer, flexible disk 48 is annular and designed to have its circumference

rests against the chamber wall of the outer, cylindrical chamber 202 and prevents a gas or liquid flow therebetween.

The inner flexible disk 216 interacts with the inner chamber 204 in the same manner as the outer flexible disk 48 interacts with the outer chamber 202.

Each of these essentially prevents gas or liquid flow in the associated chamber past the flexible disk in an inward direction.

Each of these allows a gas or liquid flow in the associated chamber past the flexible disk in an outward direction by elastically moving away from the associated chamber wall.

An annular sealing disk 50 is provided on the stem 46 and is spaced outwardly from the outer flexible disk 48. The sealing disk 50 extends radially outwardly from the stem 46 and abuts the outer chamber wall at its periphery to form a substantially gas- or liquid-tight seal therebetween. The sealing disk 50 is sufficiently rigid so that it does not deform, creating a substantially gas- or liquid-tight seal with the chamber wall as the piston 16 is moved inwardly and outwardly within the chamber 18.

As seen in Fig. 2, the piston stem 46 has a central hollow passage 52. The passage 52 extends along the axis of the piston 16 from an inner end located in the stem 46 between the flexible disk 48 and the sealing disk 50 to an outlet 54 at the outer end of the piston 16.

5 A channel 56 extends from inlet openings 58 which are on both sides of the stem

46 between the flexible disk 48 and the sealing disk 50, radially inward through the piston 16 and communicate with the central passage 52. The channel 56 and the central passage 52 allow gas or liquid communication through the piston 16 past the sealing disk 50 0 between the inlet openings 58 and the outlet 54.

An outer, annular abutment flange 62 is provided near the outer end of the stem 46 and extends radially outward from the outlet 54. As will be described later, an actuating arrangement may engage the flange 62 to move the piston 16 inwardly and outwardly within the chamber portion 12.
5

As can be seen from Fig. 2, an annular edge 140 is provided against which the sealing disk 50 can be placed so that the outward movement of the piston 16 is limited during normal pump operation. As can be seen from Fig. 3, the inward movement of the piston 16 during normal pump operation is preferably limited by the outer, flexible disk 48 being placed against the annular shoulder 206.

An annular stop disk, not shown in the embodiment illustrated in Figs. 1 to 4, may also be provided on the stem 46 between the flange 62 and the sealing disk 50 and extend radially outwardly from the stem 46, the radius of the stop disk being greater than the radius of the chamber 18, so that the stop disk limits the inward movement of the piston 16 by abutting the outer end of the chamber 18.

The operation of the pump assembly 10 will now be described with reference to Figs. 2 and 3, Fig. 2 showing the piston 16 in a fully extended, outer position and Fig. 3 showing the piston 16 in a fully retracted, inner position. The piston is moved back and forth between these two positions during pumping. As is known to those skilled in the art, the volume 218 of gas or liquid in the chamber 18 between the inner, flexible disk 216 and the outer, flexible disk 48 changes as the piston 16 is moved axially. In Fig. 2, this volume 218 is largest because the outer, flexible disk 48 is located axially outward most in the largest diameter outer chamber 202. In Fig. 3, this volume 218 is smallest because the outer, flexible disk 48 is located axially inward most in the outer chamber 202.

By moving the piston 16 inwardly from the extended position in Fig. 2 to the retracted position in Fig. 3, the volume of fluid between the two flexible disks decreases, placing the fluid thus trapped under increased pressure by causing the inner flexible disk 216 to act as a one-way valve and prevent fluid in the inner chamber 204 from flowing inwardly past it.

This pressure causes the outer flexible disk 48 to flex radially inwardly at its periphery so that it moves out of sealing engagement with the chamber wall, allowing fluid in the outer chamber 202 to flow outwardly past it and ultimately through the passage 52 and out the outlet 54.

By moving the piston 16 outwardly from the retracted position in Fig. 3 to the extended position in Fig. 2, the volume 218 of fluid between the two flexible disks increases, placing the fluid therebetween under reduced pressure by causing the outer flexible disk 48 to act as a one-way valve and preventing fluid flow in the outer chamber 202 inwardly past it.

Repeated pumping action is achieved by repeatedly moving the pump assembly 16 sequentially between positions, from the position in Fig. 2 to the position in Fig. 3 and back to the position in Fig. 2.

The flexible disk 48 must, on the one hand, essentially prevent a current from passing it during the outward stroke movement and, on the other hand, deform itself during the inward stroke movement so that a current can pass it. The illustrated

5 Disc 48 makes this possible by being designed as a thin, elastic disc,

namely by an elastically deformable edge part near the chamber wall.

When not deformed, the flexible disk 48 rests against the outer chamber wall to form a substantially gas- or liquid-tight seal. When deformed, by having the edge portion bent away from the wall, gas or liquid can flow past the disk.

The disc 48 is deformed when the differential pressure across the disc, i.e. the difference between the pressure on one side and the pressure on the other side, is greater than a maximum differential pressure that the disc can withstand without deflection. When the differential pressure is greater than this maximum differential pressure, the disc 48 deforms and gas or liquid flows past it. When the differential pressure drops below this maximum differential pressure, the disc 48 returns to its original shape, essentially forming a seal with the outer chamber wall.

The inner, flexible disk 216 is based essentially on the same principle as the outer, flexible disk 48, but it is moved away from the inner chamber wall so that it allows a gas or liquid flow past it during the inward stroke movement.

When using simple thin plastic discs 48, 216 as shown, the entire configuration of the pump assembly must be considered to obtain good results. For example, during an outward stroke, the ratio between the resistance to flow of the fluid in the chamber 18 past the inner, flexible disc 216 and the resistance to flow of the fluid 0 back through the channel 56 and passage 52 will affect the relative pressures on each side of the disc 48 as well as the deflection of the disc 48. Taking into account the viscosity of the fluid, the resistance to flow outward past the inner flexible disk 216 and the resistance to flow back inward through the piston 16 as well as the relative elasticity of the disk 48, the pump arrangement is preferably designed so that in operation, during the outward stroke movement, only the flexible disk 216 allows fluid to flow past it and during the inward stroke movement, only the flexible disk 48 allows fluid to flow past it.

The inner flexible disk 216, together with the stepped, two-diameter cylinder configuration of the chamber 18, creates an internal one-way

Valve structure which functions as a one-way valve which only allows a flow of the liquid 28 outward from the container 26 into the chamber 18.

The discs 48, 216 may be designed to resist deformation in one direction better than the other so as to provide assistance in achieving the desired function.

In Fig. 1, a liquid soap dispenser is generally indicated at 70 and is provided with the pump assembly 10 and the container 26, the pump assembly 10 being inserted into the collar 34 of the container 26. The dispenser 70 has a housing, generally indicated at 78, which receives and supports the pump assembly 10 and the container 26. The housing 78 has a back plate 80 for mounting the housing, for example, to a building wall. A lower support plate 84 for receiving and supporting the pump assembly 10 and the container 26 extends forwardly from the back plate. As shown, the lower support plate 84 has an annular opening 86 therethrough. The container 26 rests on and is supported by the plate 79, with the collar 34 extending through the opening 86 and the container 26 secured in the opening by friction or clamping or the like. A cover member 85 is connected to an upper, front extension 87 of the back plate 80.

0, which allows the exchange of the container 26 and its

Pump arrangement 10 is made possible.

The lower plate 84 carries at a front part thereof an actuating lever 88, which is arranged at 90 so as to be pivotable about a horizontal axis. An upper end

5 of the lever 88 carries a hook 94 which engages the contact flange 62 and the

Lever 88 connects to piston 16 so that movement of the lower handle end 96 of lever 88 from the position shown by solid lines to the position shown by dashed lines in the direction indicated by arrow 98 displaces piston 16 in an inward pumping stroke movement 0 as indicated by arrow 100. When the lower handle end 96 is released, spring 102 presses the upper part of lever 88 downward so that the lever

88 urges the piston 16 outwardly to a fully extended position as shown in solid lines in Fig. 1. The lever 88 and the inner hook 94 are designed to allow manual attachment and detachment of the hook 94 as necessary to remove and replace the container 26 and pump assembly 10.

In use of the dispenser 70, when pumped dry, the empty container 26 is removed together with the pump 10 attached thereto and a new container 26 with attached pump 10 is inserted into the housing. Preferably, the removed container 26 and attached pump 10 are made entirely of a recyclable plastic material which can be easily recycled without disassembly prior to cutting and shredding.

In Figs. 1 to 4, a plurality of ribs 66 are shown which are provided on the inner extension 214 and slidably engage the chamber wall of the inner chamber 204 so as to assist in the centering and axial alignment of the piston 16 in the chambers 202 and 204. Such ribs 66 are not necessary, but are advantageous. The ribs 66 are shown as axially extending, radial flanges. However, many other forms of such

0 positioning elements, for example as a disc similar to the disc

50, but with continuous openings or discontinuities therein.

Axially extending ribs 66 and/or circumferential ribs may also be provided radially outwardly from the stem 46 and abut the outer chamber wall so as to assist the piston 16 in maintaining an axial and centered position as it is moved inwardly and outwardly within the chamber 18.

While in the embodiment shown in Figs. 1 to 4 a cylindrical piston chamber 12 and piston 16 made of plastic are shown, however, piston chambers and pistons with other symmetrical or asymmetrical shapes and made of other materials can also be used.

Il · · ' JJ ···

Although a piston chamber 12 with threads 36 is preferred, other gripping means, such as an outer cylindrical member 40 with gripping means or an outer cylindrical member 40 with gripping flanges on the piston chamber 12 or elsewhere, may also be provided.

While the embodiment shown in Figs. 1 to 4 shows a channel 56 which exits from an inlet 58 on the stem 46 of the piston 16 and communicates with an axially aligned central passage 52, the channel 56 can also be designed to allow fluid communication outwardly past the sealing disk without communicating with a central passage and without an inlet 58 on the stem 46 of the piston 16.

hi Fig. 5 shows a second, modified embodiment of the pump arrangement shown in Figs. 1 to 3. In Fig. 5, the piston 16 is identical to the piston in Figs. 1 to 4. The container 26 in Fig. 5 is a unitary element which is formed integrally with the piston chamber part 12. The collar 222 of the container 26 has stepped, inner, cylindrical surfaces which represent the outer chamber 202 and the inner chamber 204 but are otherwise constructed as shown in Figs. 1 to 3

0. The operation of the pump in Fig. 5 is identical to the operation in Fig. 1

to 3.

The pump arrangement shown in Fig. 5 is particularly advantageous when the container 26 is foldable. In this respect, Fig. 5 is intended to illustrate a foldable container 26 made of plastic material, similar to tubes containing liquids such as toothpaste. The container 26 may be made of plastic by known processes such as extrusion, injection molding and/or blow molding and may have an initially open inner end 224. After the container 26 has been filled with liquid, the side walls 226 of the container are joined at the closure 228, which is a straight closure and extends completely across the container 26 from one side to the other so that the inner end 224

in a known manner. In this sense, the sealed container 26 is not symmetrical about the central axis at the end 224. A removable cap 230 is provided for closing the outlet 54. The unit shown in Fig. 5 can be sold filled with liquid and functions by manual manipulation alone, without the need for a housing, actuators or springs. The user can hold the container 26 with one hand and with the other hand move the piston 16 inward and outward so that liquid flows out as intended.

The container 26 is provided with a collar 222 and an annular flange 232 of increased thickness so as to provide relative stiffness and strength compared to the relatively thin, foldable side walls 226.

In Fig. 6, a modified embodiment of the pump assembly of Figs. 1 to 3 is shown, which is most similar to the assembly in Fig. 5. In Fig. 6, the container 26 is essentially the same as in Fig. 5, with the piston chamber portion being formed integrally with the container 26. The container 26 is preferably a cylindrical container having cylindrical side walls 226 and an annular end wall 234 and is designed to be relatively rigid and made of

0 materials such as relatively rigid plastic or glass.

The piston 16 is essentially identical to the piston in Fig. 1 to 4 except for two differences. Firstly, the contact flange 62 is enlarged so that it has a larger radial extension and is provided with an annular side flange

5 234. The annular side flange 234 supports the holding of a

Coil spring 236 between the abutment flange 62 and the flange 232 around the container collar 222. This spring 236 preloads the piston 16 into the fully extended position. The spring can be made of metal, but is preferably a resilient spring made of nylon or plastic, which can be ground and 0 recyclable.

i i i

Second, a flexible pawl 238 is provided, preferably as a part formed integrally with the piston 16, but possibly as a separate plastic part attached thereto. The flexible pawl 238 is shown as a part formed integrally with the piston 16, extending inwardly from the inner extension 214 as an elongated arm 240 with a locking lug 242 engageable internally against the flange 232 so as to more clearly prevent movement of the piston 16 outwardly beyond the fully extended position shown. The arm 240 has a narrow region 244 about which the flexible pawl can be bent so that it comes into the inactive position. The piston 16 can be inserted into the container 26 and the pawl will then automatically assume the position shown in solid lines. If it proves necessary, a one-way valve (not shown) may be provided to prevent the development of a negative pressure in the container which would prevent the pumping of liquid from the container.

In Fig. 7, an embodiment of a pump is shown which has a body 12 and a piston 16, which essentially correspond to the corresponding body and piston in Figs. 1 to 4. In Fig. 7, corresponding parts are provided with the same reference numerals as in Figs. 1 to 4.

As can be seen from Fig. 7, the function of the pump assembly 10 is identical to that in Fig. 1. The pump assembly 10 is attached to a foldable plastic container 26 with a threaded collar 34. The pump assembly has a body 12 and a piston 16. To screw the body 12 to the threaded collar 34, the body is provided with an internal thread 130 on an outer, cylindrical part 40.

The piston 16 is constructed in accordance with the piston in Fig. 4 and has a stem 46 which carries flexible disks 48, 216, a sealing disk 50 and ribs 66. The stem 46 has a passage 52, an outlet 54 and an inlet opening 58.

0 The stem 58 extends outward as a relatively narrow tube 138, which

suitable for removing liquid. The operation of the pump arrangement 10 in Fig. 7 is similar to the operation of the pump arrangement in Fig. 1 to 6.

At the open end 22 of the chamber 18, the body 12 is provided with an annular rim 140 which extends slightly radially inward from the cylindrical wall of the chamber and has an axially inwardly directed shoulder. This annular rim 140 serves as a stop against which the sealing disc 50 comes to rest so that the axial outward movement of the piston 16 is limited. The size of the rim 140 and the relative elasticity and shape of the sealing disc 50 can be selected so that the disc 50 can be bent and snapped inward past the rim 140 for easy insertion and can be bent and snapped outward past the rim 140 for removal, the removal being effected with a force which is greater than the forces effective during normal pumping operation of the pump.

Also shown in Fig. 7 is a cover part 142 which is attached to the body 12 by a snap connection, creating an airtight, annular seal around the body 12. A small opening 144 is provided at the end of the cover part 142.

In use, in accordance with an evacuation method illustrated herein, the container 26 is substantially filled with a viscous substance such as soap or hand cream or the like. The pump assembly 10 and cover member 142 are then attached. With the container preferably in a vertical

5 position, with the cover part 142 pointing upwards, a negative pressure is created at the opening

144 in the cover part 142, through which air is sucked out of the container, whereby both the sealing disc 216 and the flexible disc 48 can be deflected so that gas can flow outwards due to the effect of the negative pressure. When all the air has been sucked out, the soap-like liquid comes into contact with the sealing disc. The negative pressure required to suck the soap-like liquid past the sealing disc 214 is considerably greater than the

pressure required to extract gas. The negative pressure is selected so that the gas is simply sucked out, but the liquid is not sucked out.

The operation of the pump shown in Fig. 7 is as described above, whereby the disc 216 is moved away from the chamber wall by a negative pressure caused by the extension of the piston 16, so that liquid can flow into the chamber 18 past the disc 216. During the outward stroke movement, the flexible disc 48 remains essentially undeflected and supports the generation of suction forces in the chamber 18, so that the disc 216 is deflected and liquid flows past the disc 216.

As with the previous embodiments shown in Figs. 1-3, the fluid in the chamber 18 between the piston and the disk 216 is pressurized inwardly by retracting the piston 16. This pressure forces the disk 216 into a closed position, abutting the side walls of the inner chamber 204. This pressure deflects the periphery of the flexible disk 48 as shown in Figs. 1-3, disengaging it from the outer chamber wall, allowing fluid to flow past the disk 48 and out of the chamber 18 through the channel 56 and the passage 52.

Advantages of such a liquid-filled, evacuated container include:

1. increased impact resistance;

2. better storage stability due to the presence of oxygen over time

5 products deteriorating because the oxygen present in the air has been removed;

3. the pump assembly is primed and delivers fluid at the first pumping movement of the piston;

4. Air bubbles have been removed, which may have been trapped in the

0 pump assembly and the flow of soap from the outlet when pumping

temporarily prevent this, which could lead a user to believe that the container is empty when this is not the case.

For use in evacuating gas by means of negative pressure, the pump arrangement does not have to be designed in a special way. The pump arrangement

must simply be designed in such a way that when a negative pressure is created, one-way valve systems are present which allow air to be sucked out of the container and a much greater negative pressure is required to allow soap to be sucked past one of the one-way valves.
10

The piston 16 does not have to be inserted when the air is sucked out of the container.

The cover part 142 can also consist of a removable vacuum housing, which is provided over the body 12 and then a vacuum is applied. However, it is advantageous if some kind of cover is provided, in particular with an opening 144 through which the vacuum can be applied.

Fig. 8 shows a modified embodiment of the one shown in Figs. 1 to 3 and 5 to 7.

0 body 12. The body 12 shown in Fig. 8 corresponds essentially to the

Body in Fig. 1 to 3 with the exception that an annular recess 146 is provided between the inner, cylindrical part 41 and an outer wall 148. The annular bottom 150 of the recess 146 has a number of through-openings 152. An elastic, flexible sealing ring 154 is provided in the recess 146, which rests with a radially inner main arm 156 on the inner side wall 155 of the recess 146 and a shoulder of a radially outwardly projecting projection 158. An outer arm 160 of the sealing ring 156 rests on the outer wall 159 of the recess 146 and can be deflected radially inwards, so that a one-way valve is formed. By using this one-way valve structure shown in Fig. 8, the one-way valve structure shown in Fig. 1 or 6 can be

Pump assembly 10 may be used together with a rigid, non-foldable container 26 the neck of which is only partially visible in Fig. 8.

When used with the bottle inverted, pumping soap from the non-collapsible container 26 will create a vacuum in the container which will prevent further pumping unless it is dismantled. The action of the sealing ring 154 is to deflect the outer arm 160 so that air can enter the container through the openings 152 when a vacuum is created in the container. The sealing ring 154 prevents liquid flow out of the container through the openings 152.

The sealing ring 154 may be made of any suitable resilient material such as plastic, rubber or nylon, but is preferably made of the same material as the body 12 and piston 16 to facilitate recycling.

Although Fig. 8 has been described with reference to Figs. 1 to 3, the sealing ring 154 and a corresponding modification of the pump assembly can also be used in the same way in soap dispensers which use a more conventional pump assembly.

Claims (16)

Protection claims 1. Liquid dispenser containing (a) a liquid container (26), and
10 (b) one-way valve means (48,216) connected to the liquid container (26), characterized in that (c) on the outlet side of the one-way valve means (48,216) evacuation means (142) are provided through which gas or air can be sucked out of the liquid container (26) through the one-way valve means (48,216). 2. Liquid dispenser according to claim 1, characterized in that (a) the evacuation means comprise a cover part (142) by which the one-way valve means (48,216) can be covered, and (b) the cover part (142) has an opening (144). 25 3. Liquid dispenser according to claim 1 or 2, characterized in that the liquid container (26) is foldable. 4. Liquid dispenser according to one of claims 1-4, characterized by an arrangement (10) connected to the liquid container (26), (a) which has a chamber part (12) with a chamber (202,204) which has an outer, open end (22) and an inner end which is in communication with the liquid container (26), (b) wherein the one-way valve means (48,216) is disposed in the chamber (202,204) of the chamber part (12). 5. Liquid dispenser according to claim 4, characterized in that the cover part (142) can be placed sealingly against the arrangement (10) with an edge part around the outer, open end (22) of the chamber (202,204). 6. Liquid dispenser according to claim 4 or 5, characterized by a snap connection between the cover part (142) and the chamber part (12). 7. Liquid dispenser according to one of claims 4-6, characterized in that the one-way valve means (48,216) are designed to (a) a gas and/or liquid flow through the chamber (202,204) past the one-way valve means (48,216) only from the liquid container (26) 0 outwards towards the outer, open end (22) of the chamber (202,204) allow, (b) a gas or air transport through the chamber (202,204) past the one-way valve means (48,216) from the liquid container (26) outwardly to the outer, open end (22) of the chamber (202,204) only when a negative pressure is applied to the one-way valve means which is further below atmospheric pressure than a first negative pressure, and 0 (c) a fluid transport through the chamber (202,204) to the disposable Valve means (48,216) past the liquid container (26) to the outside 21 to the outer, open end (22) of the chamber (202,204) only when a negative pressure is applied to the one-way valve means which is further below atmospheric pressure than a second negative pressure, the second negative pressure being further below atmospheric pressure than the first negative pressure. 8. Liquid dispenser according to one of claims 4-7, characterized in that the arrangement (10) has a piston-forming element (16) which is arranged to be slidable in the chamber (202, 204), so that liquid can be removed from the liquid container by an inward and outward directed, axial sliding movement of the piston-forming element (16) in the chamber (202, 204). 9. Liquid dispenser according to one of claims 4-8, characterized in that (a) the chamber (202,204) has a cylindrical chamber wall, (b) the one-way valve means (48,216) comprises at least one valve provided on a stem (52) provided coaxially within the cylindrical chamber wall, 0 flexible disc (48,216) included, (c) each flexible disc (48,216) extends radially outwardly from the stem (52) so as to circumferentially abut the chamber wall, (d) each flexible disc (48,216) having an inwardly directed Liquid flow in the chamber (202,204) directed towards the liquid container (26) past the flexible disc (48,216) is substantially prevented, and 0 (e) each flexible disc (48,216) is elastically deformable so that it can be moved by the Chamber wall of the chamber (202,204) is movable away and a outwardly directed fluid flow in the chamber (202,204) past the flexible disk (48,216). 10. Liquid dispenser according to claim 8 or 9, characterized in that the piston-forming element (16) has an axially extending stem (52) and the one-way valve means (48,216) contain at least one flexible disk (48,216) provided on the stem (52), which extends radially outwardly from the stem and circumferentially rests against the chamber wall. 11. Liquid dispenser according to claim 9 or 10, characterized in that each flexible disc (48,216) has an elastically deformable edge part provided on the circumference for abutting against the chamber wall. 12. Liquid dispenser according to one of claims 9-11, characterized in that the one-way valve means (48,216) comprise at least two such flexible discs (48,216) which are provided at a distance from one another on the stem (52). 13. Liquid dispenser according to one of claims 4-12, characterized in 0 that the arrangement (10) is interchangeably connected to the liquid container (26) is. 14. Liquid dispenser according to one of claims 2-13, characterized by means for generating a negative pressure at the opening (144) of the cover part (142). 15. Liquid dispenser according to one of claims 1-14, characterized in that said liquid contains a viscous liquid. 16. Liquid dispenser according to one of claims 1-15, characterized in 0 that the liquid in question contains a liquid soap.