The present invention relates to a dispenser for a highly viscous fluid, in particular toothpaste contained in a collapsible tube, said collapsible tube having a body part, defining a storage cavity for said highly viscous fluid, and a neck part with an external shoulder, where the neck part has a pas- sage through which the fluid may be removed, said dispenser comprising an adaptor, a pump, and tube gripping means.

As it is commonly known, toothpaste and other highly viscous fluids are commonly provided in col- lapsible tubes.

One of the drawbacks of such collapsible tubes is their lack of aesthetic appearance, especially when they have been squeezed in order to remove the paste from them. Another well established fact is that some people are disturbed by the fact that other members of their household squeeze the middle part of the collapsible tubes. In particular in the case of toothpaste it is another drawback is that some people find that the way the toothpaste is squeezed out of the collapsible tube directly onto other peoples toothbrushes is not hygienic.

In order to overcome these drawbacks it has been suggested to use dispensers in connection with the collapsible toothpaste tubes.

Such dispensers often include a container, in which the collapsible tube is accommodated. The con- tainer may then be given the desired aesthetic ap- pearance whilst at the same time preventing people from squeezing the collapsible tube directly, in par- ticular at the middle. However, this use of a con- tainer necessitates the use of some other means than the direct manual squeezing of the collapsible tube

in order to remove the paste from the collapsible tube.

In WO-A-94/25358 and in DE-U-29918511 dealing with dispensers for toothpaste it has been suggested to use various kinds of urging means, indirectly squeezing the collapsible toothpaste tube. These so- lutions are, however, quite complicated. Moreover, with the urging means suggested it is very difficult to empty the collapsible toothpaste tube fully. This is because they rely on the indirect application of external force to the collapsible tube. Because the external force is applied indirectly, the force may not be applied as selectively as in the case of di- rect manipulation. Accordingly, it is often not pos- sible to selectively press the last toothpaste out of the collapsible tube.

For low viscous fluids a number of dispensers using pumps are known, e. g. of the kinds disclosed in GB-A-2155117, US-A-5474212, EP-A-362835 and DE-A- 4341270. These dispensers have the common feature that they are adapted for highly flexible bags. The pump is connected to a suction tube, which reaches to the bottom of the bag. The pump thus empties the flexible bags by extracting liquid from the bottom thereof. During this process the flexible bags col- lapse under the pressure from the outside air.

There are at least two problems with these known dispensers. One is that they are adapted to be used with flexible bags. Common collapsible tooth- paste tubes are, however, quite rigid, especially around the top and shoulder parts. Thus they will not collapse properly under isostatic pressure from the outside air. Moreover, because the collapsible tube is quite rigid, the toothpaste has a high viscosity, and air or other fluid does not replace the dispensed fluid, the toothpaste extracted from the bottom of the collapsible tube will not be replaced. The gravi-

tation alone on the toothpaste would not allow de- forming the quite rigid collapsible tube sufficiently for the toothpaste to fall to the bottom. Conse- quently if the abovementioned pumps were to be used in conjunction with a common collapsible toothpaste tube, the collapsible tube would collapse at the bot- tom only and eventually block the entry opening of the suction tube, long before the collapsible tube is empty.

Moreover the opening of a standard collapsible toothpaste tube is too narrow for the pumping mecha- nism to be inserted into the collapsible tube, if the pump is to dispense a useful volume of toothpaste in one stroke.

Finally, it is well known that some highly vis- cous fluids, such as toothpaste, are prone to drying out when exposed to air. This may the cause the dis- pensers known in the art to clog.

It is the object of the present invention to provide a dispenser for the use with standard col- lapsible tubes of highly viscous fluids, in particu- lar toothpaste tubes, which overcomes the above prob- lems and which at the same time provides for easy re- placement of the tube, ease of use of the dispenser, optional design of the dispenser exterior, material and appearance and thus optional placement of the dispenser, e. g. on a table or wall mounting.

According to the invention this object is in a dispenser according to the opening paragraph solved by the pump comprising a pump mechanism and a pump tube connected to the pump mechanism, and that the tube gripping means are adapted to grip the neck part of the collapsible tube, and hold and secure the col- lapsible tube in a substantially vertically suspended position, the gripping means and the pump further be- ing arranged so as to allow the pump tube to extend

into the tube through said passage in the neck part in a non-blocking manner.

This arrangement allows the air pressure in the storage cavity of the collapsible tube to be equal- ized by the external air, when the inherent elastic- ity of the collapsible tube tries to force it back to its natural shape. In this manner the collapsible tube regains its natural shape because air is allowed into the tube to compensate for the dispensed fluid, thereby allowing the highly viscous fluid to fall to the lower part of the collapsible tube. Since the pump tube reaches to the bottom of the collapsible tube this allows all of the highly viscous fluid to be gradually removed, as it flows to the bottom of the storage cavity.

Moreover, because the pump tube always extracts the highly viscous fluid from the bottom, the risk of the highly viscous fluid drying up is reduced, be- cause only the upper surface thereof is exposed to evaporation.

In a preferred embodiment the gripping means are arranged so as to hold the neck part of the tube adjacent to a chamber into which there is free access from the storage cavity through said non-blocked pas- sage.

This has major advantages when the highly vis- cous fluid is toothpaste, food products or the like where it is desired to minimize the risk of the fluid drying out.

This is because the air volume needed to be supplied to the collapsible tube instead of the ex- tracted volume of highly viscous fluid will in the first instance essentially be drawn from this cham- ber, in particular when the collapsible tube is al- most full, as in the case of a new collapsible tube.

In an additional embodiment thereof the chamber has at least one air pressure equalising access.

Having an equalizing passage allows external air to enter into the chamber, thus subsequently equalizing the pressure, which, due to the extracted highly viscous fluid, is reduced in the otherwise closed system of the cavity and the chamber.

In a preferred embodiment of the dispenser the gripping means is provided by an aperture in a wall of said chamber.

This conveniently makes the gripping means con- stitute one of the walls of the chamber.

In a second embodiment the gripping means are provided by a number of ribs extending in radial di- rection with regard to the pump tube.

This is particularly convenient if one wishes to make use of the entire volume within the casing for forming the chamber.

In another embodiment said air pressure equal- izing access is arranged in conjunction with the gripping means.

This is advantageous, because the air drawn into the chamber to equalize the pressure is replaced with air not coming directly from the external air.

This lack of direct access of external air further prevents the highly viscous fluid from drying out.

The preferred embodiment of the air pressure equalizing access is providing it by the manufactur- ing tolerances between the aperture and the neck of the collapsible tube.

It has shown that for allowing for an appropri- ate pressure equalization between the cavity and the chamber, the volume of the chamber should be at least one tenth of the total volume of the storage cavity of the tube.

In a further preferred embodiment of the inven- tion a first opening is provided at said first end and that the adaptor is adapted be detachably mounted at said first end so as to cover said opening.

This is a convenient way of making it possible to introduce the collapsible tube in the casing.

Moreover it may allow for the adaptor to fit differ- ent shapes of casings.

However, in another preferred embodiment the adaptor is an integral part of the casing.

This is advantageous in the sense that the dis- penser may be a self-contained one-part unit.

The foregoing summary, as well as the detailed description of the preferred embodiments will be bet- ter understood when read in conjunction with the ap- pended drawings. For the purpose of illustrating the invention, there are in the drawings shown embodi- ments, which are presently preferred, it being under- stood, however, that the invention is not limited to the precise arrangements and instrumentalities dis- closed. In the drawings, fig. 1. illustrates a partially sectional side view of one embodiment of the present invention, fig. 2 illustrates a partially sectional side view of a second embodiment of the pump and chamber arrangement, fig. 3 illustrates a partially sectional side view of a third embodiment of the present invention, with another example of the gripping means and the chamber, fig. 4 illustrates a partially sectional side view of a fourth embodiment of the present invention with still different gripping means and chamber, fig. 5 illustrates a partially sectional side view of a fifth embodiment of the invention in which the adaptor is integral with the casing.

Referring to the drawings, in which the same reference numerals designate corresponding elements throughout the figures, there is in figure 1 shown a partially sectional side view of the dispenser in ac- cordance with the present invention. The dispenser

comprises an optional casing 1. The casing has a first opening la at one end. The size of the casing 1 is selected to accommodate a desired standard col- lapsible tube 100. An adaptor 2 covers the opening la. In this embodiment, and in the embodiments of figs. 2-4 the adaptor 2 is detachably mounted over said one opening la of the casing 1.

Inside the dispenser, and mainly within the casing 1 is placed a collapsible tube 100 containing highly viscous fluid, such as toothpaste, grease, foodstuff, or the like. The collapsible tube is of a standard type, and includes a body part and a neck part 200 including a passage 200a and a shoulder 201.

The dispenser further comprises a pump with a pump mechanism 3, a pump tube 4 and a dispensing noz- zle 51 integrated in a plunger 5. The actual internal construction of the pump mechanism 3 is not consid- ered of relevance for this invention. Rather, the pump mechanism 3 is of a conventional type known to those skilled in the art and only a matter of appro- priate selection. In order to simplify the illustra- tion, the pump mechanism 3 and pump tube 4 are only shown in plan view. The pump tube 4 may be an inte- gral part of the pump mechanism 4 or it may be a separate attached element. The latter is preferred.

Preferably, the adaptor 2 has a size allowing the pump mechanism 3 to be located therein. The pump tube 4, however, extends out of the adaptor.

The pump tube 4 has a length allowing it to reach the bottom of the collapsible tube 1, when the collapsible tube 100 is placed in a gripping means 6 in a manner to be described below. The pump tube 4 further has external cross sectional dimensions al- lowing it to fit inside of the passage 200a. In par- ticular, the external dimensions of the pump tube are chosen so as to prevent the pump tube 4 from blocking the passage 200a.

As already indicated, the dispenser further comprises a gripping means 6 for the collapsible tube 100. The gripping means is designed to hold the col- lapsible tube 100 in a substantially vertically sus- pended position. In this respect it should be noticed that no other means for supporting the collapsible tube exists, e. g. it is not resting on the bottom 12 of the casing 1. This has the advantage that if the pump tube 4, as preferred, is separate element, the dispenser may be used for a variety of different sizes of collapsible tubes, just by selecting a pump tube of an appropriate length. This is a simple op- eration, which may be accomplished by the user, if pump tubes of different lengths are supplied with the dispenser.

When the collapsible tube 100 is secured in the vertical position the highly viscous fluid will, un- der the influence of gravitation, gather in the bot- tom of the storage cavity C3. The gripping means 6 supports the collapsible tube 100 by engaging it at or in the vicinity of the neck part 200. In Fig. 1 the gripping means 6 is an aperture in the lower wall 21 of the chamber C3. In fig. 1 the edges of the ap- erture in the lower wall engage underneath a cap of the collapsible tube 100. However, it is well possi- ble that the gripping means simply engages an outer thread of the neck 200. This would be the case if the collapsible tube were provided with a removable screw cap.

Though not illustrated the edges of the aper- ture could be rounded and made slightly thicker than the wall 21, so as facilitate insertion of the col- lapsible tube.

In order to fit different types of collapsible tubes 100 with different diameters of the neck part 200, the edges of the aperture may be foreseen with

an elastic material, such as natural or synthetic rubber.

If instead, e. g. for reasons of customer lo- yalty, only one specific type of collapsible tube should be useable with the dispenser, the gripping means could involve an aperture in the form of a threaded bore. The thread in this case matches a cor- respondingly threaded neck part 200.

In the embodiment of fig. 1, the gripping means 6 are provided in the lower wall 21 of the chamber C2 extending from the outer wall of the adaptor 2 and the aperture therein. Accordingly, the outer walls of the adaptor 2 form chamber C2. This is also the case in the embodiments of figs. 2 and 5.

In the embodiments of fig. 3 and 4 the chamber C2 is provided as a separate chamber within the adap- tor 2. This may involve advantages in the manufacture and possible assembly of the adaptor 2, the pump and the chamber C2, as these may be manufactured as indi- vidual parts or they may be integrally manufactured.

An important aspect of the present invention is to ensure that external air has a limited degree of access to the storage cavity C3 inside of the col- lapsible tube 100, in order to compensate for the volume of highly viscous fluid dispensed from the dispenser, but at the same time limit the volume of air available for this action to prevent possible drying-out of the viscous fluid in the casing.

The limited air access to the inside of con- tainer may be achieved in a number of ways.

The preferred way is by means of differences in manufacturing tolerances of the gripping means in the form of the aperture in the wall 21. Alternatively, however, the gripping means could be formed as arms projecting radially inward from the outer wall. The slits between the radially inward projecting arms would then form the means for the air access.

In fig. 1 air would then be drawn from the ex- terior through a first gap between the casing 1 and the adaptor 2 and through a second gap between the neck part 200 and the wall 21, into the chamber C2 and eventually into the storage cavity C3.

If however, the edges of the aperture in the wall 21 is formed from elastic material, e. g. to al- low for various sizes of collapsible tubes, the abovementioned gap may not exist. In this case it would be necessary to provide separate air pressure equalizing access, e. g. in the form of pinholes. In fig. 1 such pinholes are illustrated. Pinhole Al com- municates with the interior of the casing 1, whereas the pinhole A2 communicates directly with the exte- rior of the dispenser.

Depending on the embodiment different types of access may be envisaged. Thus, in the embodiment of fig. 2 air may pass through along the outside of the pump mechanism 3. The pump mechanism in fig. 2 being a separate part fitted from the outside in the upper wall of the chamber C2.

In fig. 4 the chamber C2 is formed integrally with the pump mechanism 3. Also in this case air may enter along the outside of pump mechanism 3. It may, however, also pass through a pinhole Al in the lower wall 21 of the chamber C2 or between the wall 21 and the neck part 200 of the collapsible tube 100. In fig. 3 the chamber C2 is also formed integrally with the pump mechanism 3. Here the air may pass through a pinhole Al in the lower wall 21 of the chamber C2 or between the wall 21 and the neck part 200 of the col- lapsible tube 100.

In fig. 5 the adaptor 2 is integral with the casing 1. Here air may pass between the lower wall 6 of the chamber C2, through a pinhole Al or through a pinhole A2. All of these pinholes communicate di- rectly with the external air, because no bottom wall

is foreseen in the casing 1. The reason for the lack of a bottom wall is the need to be able to introduce the collapsible tube 1 into the casing. This evi- dently cannot be done from the top, because the adap- tor 2 is integral with the casing 1.

In the other embodiments shown in figs. 1 to 4 the adaptor is detachably mounted on at one end of the casing 1 in which an opening la is provided. The collapsible tube 100 may then be placed in the grip- ping means located in the adaptor 2 and the adaptor subsequently be placed over the opening la in the casing 1.

In the embodiments shown in Figs. 1 to 4 the casing 1 has a narrower upper part 11 over which the adaptor may be slid. The adaptor then rests on the shoulders 13 formed by the transition from wide to narrow. Other arrangements are well possible, e. g. the narrower part and the adaptor 2 could have match- ing threads. This would be particularly useful if the adaptor was to be wall mounted.

The dispenser of fig. 1 works in the following manner.

The pump mechanism 3 is activated by a down stroke of the plunger 5. The stroke of the plunger 5 extracts a certain volume of the highly viscous fluid from the bottom of the collapsible tube 100. The highly viscous fluid is extracted through the pump tube 4, the pump mechanism 3, the plunger 5 and dis- pensed through the nozzle 51.

When the highly viscous fluid is removed the collapsible tube 100 collapses slightly. Since the chamber C2 and the storage cavity C3 are connected air from the chamber C2 replaces some of the ex- tracted volume of highly viscous fluid.

In order to facilitate the replacement, in par- ticular when the collapsible tube 100 is full is the case with a new collapsible tube 100, the chamber C2

should have a substantial size. It has been found that a chamber size of approximately one tenth of the total volume of the collapsible tube 1 is appropri- ate.

However, even though the collapsible tube is collapsible it does have a certain rigidity, forcing it towards a natural uncollapsed state. This force allows air to be slowly sucked in to the chamber C2 via the possible types of access referred to above, thereby equalizing the pressure in the storage cavity C3 and the chamber C2. The collapsible tube thus re- gains its natural uncollapsed state.

In the uncollapsed state the highly viscous fluid is able to fall to the bottom of the collapsi- ble tube, thereby forming a surface with air over it.

Because of the lack of direct access of exter- nal air this surface is not exposed to any substan- tial degree of drying-out. Moreover, the highly vis- cous fluid pumped out will not be dry, as it is al- ways extracted from the bottom.

Accordingly the collapsible fluid will not dry out and clog the pump mechanism 3, the pump tube 4 or the nozzle 51.

The invention thus provides a convenient clog free dispenser for collapsible tubes with highly vis- cous fluids, in particular such fluids as toothpaste or the like which are prone to dying out.

The person skilled in the art will appreciate that the above embodiments are examples only, and that numerous variations are possible without depart- ing from the scope of invention.

In particular the skilled person will realize that the gripping means and the pressure equalizing means may take different forms than the examples de- scribed here.