US20080023487A1

US20080023487A1 - Fluid product dispenser with collapsible reservoir and tensioning means therefor

Info

Publication number: US20080023487A1
Application number: US11/702,722
Authority: US
Inventors: Berend Douwes
Original assignee: Technical Concepts Bentfield BV
Current assignee: Technical Concepts Bentfield BV
Priority date: 2006-02-07
Filing date: 2007-02-06
Publication date: 2008-01-31
Also published as: DE602007000867D1; ATE428339T1; PL1815776T3; ES2326046T3; EP1815776A1; EP1815776B1

Abstract

A dispenser for dispensing a fluid product includes an assembly of a collapsible reservoir and a pump, a housing for removably accommodating the assembly, and means for actuating the pump. The housing includes a tensioning element, or tensioning means, which is configured to counteract, or negate, compression of the collapsible reservoir as fluid is removed from the collapsible reservoir. By counteracting compression of the collapsible reservoir, the tensioning element, or tensioning means, may prevent trapping of fluid product in the collapsible reservoir.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority pursuant to the Paris Convention to European Patent Application 06075257.3, filed Feb. 7, 2006, the disclosure of which is hereby incorporated herein, in its entirety, by this reference. This application also claims the benefit of U.S. Provisional Application No. 60/771,483, filed Feb. 9, 2006, the disclosure of which is hereby incorporated herein, in its entirety, by this reference.

FIELD OF INVENTION

The present invention relates to a dispenser for dispensing a fluid product and, more specifically, to a dispenser that includes a reservoir and an associated tensioning means for counteracting contraction of the reservoir when the reservoir is at least partially filled.

BACKGROUND OF RELATED ART

Fluid product dispensers with collapsible reservoirs and pumps for drawing fluid from the collapsible reservoirs and dispensing the fluid are well known. An example of such a fluid product dispenser is described inter alia in U.S. Pat. No. 5,445,288. Such dispensers are, for example, employed in washrooms, toilets, kitchens, hospitals, surgeries, hair/beauty salons, workshops and factories. In many cases, such dispensers are mounted to a wall, often in the vicinity of a basin, bath, shower or toilet bowl; alternatively, such dispensers may be free-standing, and may be placed on a shelf, worktop or wash hand basin, or a trolley. In use, the actuating means are typically operated by hand, arm or elbow so as to dispense a quantity of fluid product. In many applications, a fluid product will be dispensed into the operator's hand or onto a carrier, such as a cloth, after which the fluid product is rubbed onto skin, or is applied from said carrier onto a surface to be treated, such as a metal or ceramic surface to be cleaned, for example.
Because the reservoir in such a dispenser is collapsible, and because the pump withdraws liquid product from the reservoir without an air return (or substantial flow of other gas) back into the reservoir, the reservoir will steadily contract in upon itself as more and more of the liquid product is withdrawn by the pump. Such contraction tends to push liquid product out of the reservoir, helping to ensure that the reservoir is substantially emptied before it has to be replenished. However, despite this contraction effect, a certain amount of liquid product nevertheless tends to get trapped in the reservoir, particularly along folds, seams and/or gussets that may be present in the reservoir, or in internal corners; such product is essentially wasted, since it is discarded with the old reservoir once a new reservoir is loaded into the housing. The quantity of liquid product wasted in this manner depends inter alia on the viscosity of the liquid product.
This wastage problem can become particularly significant in the case of relatively viscous liquid products such as thick soap or detergent solutions, especially those containing a suspended granulate solid; liquid products containing such a granulate solid often contain chemicals that deliberately increase their viscosity, so as to prevent the particles of the granulate solid from settling or floating out of homogeneous suspension. Many such liquid products can have viscosities of the order of 10⁴to 10⁵times as high as that of a watery soap solution typically used in conjunction with a foam or spray pump, for example. In tests, it has been observed that, even when the employed reservoir is a thin-walled plastic foil bag (see, e.g., U.S. Pat. No. 5,732,853), as much as 6 to 8% of the initial load of liquid product can get trapped in the reservoir when high-viscosity liquid products are used; this percentage is significantly higher when the employed reservoir is a relatively stiff-walled collapsible container, as in the abovementioned U.S. Pat. No. 5,445,288, for example.
The trapping of liquid product within collapsible reservoirs is somewhat undesirable for a number of reasons. For example, the liquid products concerned often contain relatively expensive chemicals, e.g., to keep them aseptic, prevent clotting, maintain the correct buoyancy level for suspended granulates, effectively dissolve various types of dirt, etc. As a result of the use of these chemicals, the products can cost on the order of about $100 per gallon (or about
20 per liter). Wasted liquid product can therefore translate to relatively significant sums of wasted money.
As another example of the undesirability of wasted liquid product within a collapsible reservoir, the presence of substantial quantities of trapped liquid product in a depleted reservoir will generally mean that that reservoir will have to be treated as chemical refuse rather than as simple plastic residue. This obviously puts a greater potential strain on the environment. As a result, more elaborate disposal procedures are necessary, with an attendant increase in costs.
It should also be noted that many jurisdictions are currently considering stringent legislation to force manufacturers to package their wares in an environmentally responsible manner. However, as a possible alternative to such legislation, some governments are willing to first evaluate the results that can be achieved by self-imposed waste-reduction covenants in various branches of industry. Manufacturers would generally prefer to have to work with such self-imposed covenants than with more explicit legislation, and are thus eagerly seeking measures to reduce waste.

SUMMARY OF THE INVENTION

For purposes of clarity and consistency, the following terms as used throughout this text and the appended claims:
The term “fluid” may be interpreted to include a liquid, a suspension of a granulate solid in a liquid, a gel, and a foam, for example.
The term “product” may be interpreted to include soap (including shower gel), detergent, and exfoliating scrub, as well as mixtures of these substances, for example.
The “liquid product” may be dispensed directly through the pump, or may first be mixed with another substance, such as air or another gas, another liquid, or a granulate solid, for example.
The term “pump” refers to any type of pump suitable under the circumstances. The pump in question may employ a piston, bellows, and/or membrane, for example.
A dispenser according to the present invention may include a housing for removably accommodating an assembly that includes a collapsible reservoir and a pump. The collapsible reservoir is configured to contain a liquid product. The pump is connected to the reservoir and is configured to dispense a fluid product using the liquid product as an input. When the assembly is accommodated in the housing, the pump may be located at the underside of the reservoir. The liquid product may be withdrawn by the pump from the reservoir without a substantial gas flow back into the reservoir. The dispenser may further include actuating means for actuating the pump so as to dispense fluid from the pump to the exterior of the assembly. In addition, a dispenser that incorporates teachings of the present invention may be configured to help reduce waste of liquid product, such as liquid product that may otherwise be trapped in a collapsible reservoir.
The collapsible reservoir of a dispenser of the present invention may have a relatively flat form when empty and a relatively bulged form when at least partially filled, whereby bulging of the reservoir along a first direction occurs as a result of corresponding contraction of the reservoir along a complimentary second direction. To counteract, or negate, this contraction, the dispenser (e.g., the housing thereof) may include tensioning means for applying an external force to the reservoir which is tensile along the second direction.
Since bulging of a collapsible reservoir may be caused by the act of (partially) filling an empty reservoir that is relatively flat to start off with, a constant attempt to negate this bulging may thus amount to a constant attempt to revert the reservoir to flatness and emptiness. Stated another way, the tensioning means in the housing according to the invention may actively squeeze liquid product out of the reservoir, rather than just passively relying on gravity to cause as much liquid product as possible to migrate toward the pump. By applying a tensile force along the second direction, the bulging of the reservoir is pulled inward in a substantially homogeneous manner, thus decreasing the risk that excessive crumpling of the reservoir will occur, and therefore reducing the attendant risk of liquid product getting trapped in the internal folds, corners, etc., arising from such crumpling.
In an embodiment of a dispenser according to the invention, the tensioning means may include suspending means for suspending the reservoir by a first extremity so that it hangs under the force of gravity, the pump being attached to a second extremity of the reservoir located opposite the first extremity. Because the reservoir is hung up in the housing rather than, for example, sitting on a retaining shelf, the weight of the reservoir and its contents apply a tensioning force to the reservoir along the vertical direction (second direction), thus serving to counteract the (net) outward bulging of the reservoir in the horizontal direction (first direction).
In some embodiments of a dispenser according to the invention, the suspending means may include a drum that can be rotated about a substantially horizontal axis. Such a drum may be rotationally/torsionally biased (e.g., using a spiral spring, elastic belt, etc.) in a first rotational sense, and the top of the reservoir may be hung on the drum in such a manner that the weight of the reservoir (including any liquid product therein) exerts a moment on the drum in a second rotational sense opposite to the first rotational sense. It has already been set forth above that, as the empty reservoir is filled, it starts to bulge outward along a first direction, which causes an attendant contraction of its length along a complimentary second direction; conversely, as the reservoir is emptied, the tensile force applied by the tensioning means according to the invention causes the reservoir to expand along the second direction in response to an attendant decrease of the bulge along the first direction. In a situation as set forth in the preceding paragraph, in which the top (first extremity) of the reservoir were simply hung from a fixed point, this lengthening would tend to cause the lowest point (second extremity) of the reservoir to move steadily downward as the reservoir was emptied; however, since the pump is attached to this lowest point, and since it is generally desired to keep the pump and its connection to the reservoir at a fixed level/posture, such steady downward motion may be undesirable. The biased drum set forth at the start of this paragraph addresses this issue in that, as the reservoir empties, its weight decreases, as a result of which:

- the moment exerted by the reservoir in the second rotational sense reduces, so that;
- the drum can relax in the first rotational sense, as a consequence of which;
- the upper portion of the reservoir is “rolled onto” the drum, thus taking up the slack caused by the expansion of the reservoir along the second direction, and, thus;
- the lower portion of the reservoir can remain at a steady level in the dispenser.

In tests of such a dispenser according to the invention, the inventor used a thick soap solution comprising a suspended granulate solid; commercially available examples of such a solution/suspension include Deb SWARFEGA™, Stockhausen STOKO SOLOPOL™ and CWS ABRASIVA™. The viscosity of this (thixotropic) solution/suspension was measured to be on the order of 10⁵centipoise in static measurements, and of the order of 4×10³centipoise in dynamic measurements. The employed reservoir was a plastic foil bag having two major opposing flat surfaces, which were sealed together at the head and foot and were joined at the sides by foil sheet parts with a central longitudinal folding seam; in this manner, the reservoir could collapse flat in a concertina-like fashion. This reservoir was suspended from a drum arrangement as set forth in the preceding paragraph. It was observed in this instance that as little as 0.9 to 2% of the initial load of viscous liquid product got trapped in the reservoir, which represents an improvement of a factor of at least three (and, in many cases, a factor of eight or more) compared to the results obtained using a non-inventive dispenser (see “BACKGROUND OF RELATED ART” above).
The pump may include a liquid inlet valve for admitting liquid product into the pump from the reservoir, the influx of liquid product through the valve occurring along a flow axis; and the housing comprises clamping means for clamping the pump in a given posture, whereby the pump is thus postured by the clamping means that the flow axis is substantially horizontal. When the pump is actuated so as to dispense fluid, the liquid inlet valve may shut tightly so as to minimize migration of liquid product from the pump back into the reservoir. In the case of a liquid product containing a suspended granulate solid, a build-up of granulates within the liquid inlet valve (e.g., between a ball bearing/flap member/top hat member and a corresponding valve seat, or in the throat of a duckbill valve) can prevent the valve from shutting properly, and this can result in the creation of a substantial dead volume upstream of the valve. However, by ensuring that the flow axis into the valve is substantially horizontal, such an accumulation of granulates in the valve may be minimized. It is believed that if a buoyancy imbalance arises and granulates start to precipitate out of suspension, they will either sink downward (parallel to the direction of gravity) or float upward (anti-parallel to the direction of gravity). In the event of a vertical flow axis through the valve, a sinking effect would tend to cause a forward accumulation of granulates at the entrance side of the valve, whereas a floating effect would tend to cause a similar backward accumulation at the exit side of the valve, either of which would eventually lead to incorrect operation (jamming) of the valve. However, by arranging the flow axis to be horizontal (or, at least, substantially horizontal), the component of gravity along the flow axis is zero (or, at least, substantially zero), thus, it is currently believed, avoiding the accumulation effects described above.
As indicated in the opening paragraph, when the assembly of reservoir and pump is accommodated in the housing, the pump is located at the underside of the reservoir. For example, a throat may be provided at (or proximal to) the lowest point of the reservoir, and this throat may be connected to the liquid inlet valve of the pump (see previous paragraph) using a duct; see, e.g., the abovementioned U.S. Pat. No. 5,732,853. The inventor has observed that, in the case of viscous liquid products as alluded to above, the distance H between the liquid inlet valve of the pump and the point at which the pump is attached to the reservoir is preferably kept as short as possible; for example, in the previous sentence, said duct is ideally kept as short as possible (without sacrificing practicality). In this manner, pressure loss in the head H is kept to a minimum, so that the ability of the pump to suck liquid product out of the reservoir is optimized. This helps achieve a further reduction in the amount of liquid product trapped in the reservoir.
The actuating means of a dispenser of the present invention may include at least one of:

- an actuating organ movably connected to the housing and serving to cooperate with said pump, whereby the pump can be actuated by manually moving the actuating organ;
- a detector, for detecting that a member onto which fluid is to be dispensed has been offered to a dispensing head of the pump; and
- an electric actuator, for actuating the pump on the basis of a signal output from the detector.

Other features and advantages of the present invention will become apparent to those of ordinary skill in the art through consideration of the ensuing description, the accompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be elucidated in more detail on the basis of the accompanying schematic drawings, which depict examples of various aspects and features of the present invention, and in which:
FIG. 1 renders a perspective view of an example of a dispenser;
FIG. 2 renders a longitudinal cross-sectional view of the subject of FIG. 1, taken along the line A-A′; and
FIG. 3 renders a longitudinal cross-sectional view of a dispenser according to an embodiment of the current invention.
In the drawings, corresponding elements are denoted by corresponding reference symbols.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 renders a schematic perspective view of part of a dispenser 10 for dispensing a fluid product. FIG. 1 shows a housing 12, which can be mounted to a wall of a washroom, for example. The housing 12 accommodates an assembly C that includes a collapsible reservoir 20, for containing a liquid product, and an attached pump 22; these items are only visible in FIG. 2, and will be discussed later in more detail. Actuating means 14 are movably connected to the housing 12, and can be actuated so as to operate said pump 22. Also shown are an inspection window 16, which allows the amount of liquid product in the reservoir 20 to be seen from outside. An aperture 18 allows insertion of a tool with the aid of which the housing 12 can be unlocked and opened, allowing access to the assembly C (including reservoir 20 and pump 22) located within. The housing 12 is made from any suitable rigid material, such as metal or a plastic, for example.
FIG. 2 renders a cross-sectional view of the subject of FIG. 1, taken along the line A-A′. The reservoir 20 is now visible, and is here embodied as a flexible plastic container. The liquid product contained in the reservoir 20 may, for example, include soap, shower/bath gel, detergent, exfoliating scrub, or mixtures of (certain of) these products.
A pump 22 is attached to the underside of the reservoir 20, so as to be able to draw liquid product from within the reservoir 20; since the pump 20 does not replace such withdrawn liquid product by air (or another gas), the reservoir 22 collapses inward as more and more liquid product is withdrawn therefrom. The pump 22 may be any suitable type of pump for the application in question, such as a liquid pump, spray pump or foam pump, for example, and may operate on the basis of a movable piston, bellows and/or membrane, for example. In operation, the pump 22 may directly dispense the liquid contained within the reservoir 20, or may first mix it with air to form a spray or foam, for example. The pump 22 dispenses a fluid product from the nozzle 24. More information with regard to pumps suitable for use in this type of application can, for example, be gleaned from U.S. Pat. No. 5,271,530 and U.S. Patent Application Publication 2004/0149777, and from the website www.airspray.nl, the disclosures of each of which are incorporated herein, in their entireties, by this reference.
As can be seen in FIG. 2, the actuating means 14 in this instance are hinged to the housing 12 via a hinge joint 26. This, together with the gap 28 below the actuating means 14, ensures that the actuating means 14 can be swung in and out of the housing 12. An arm 30 connects the actuating means 14 to the pump 22 in such a manner that, when the actuating means 14 are swung into the housing 12 about hinge point 26, arm 30 operates pump 22 so as to dispense a dose of fluid product through the nozzle 24. Biasing means, such as spring 32, ensure that the actuating means 14 are urged back into their swung-out position when released. In many applications, a user depresses the actuating means 14 using his hand palm, lower arm or elbow, for example, and collects the fluid product dispensed from the nozzle 24 in his hand or on a carrier (such as a cloth or tissue); in such applications, the nozzle 24 will generally face substantially downward.
The pump 22 is removably mounted to a bracket 36 that protrudes from the back wall 34 of the housing 12. This back wall 34 can be provided with screw-holes, magnets, or other means for mounting it to a wall or other surface. Also protruding from the back wall 34 is a lug 38B, which grips a cooperating lug 38A; however, using a tool inserted through aperture 18, these two lugs 38A, 38B can be disengaged, allowing the housing 12 to be opened, e.g., so as to replace the reservoir 20 and/or pump 22 located inside (this may involve replacing either the entire assembly C as a whole, or replacing the reservoir 20 or pump 22 as parts).
As is evident from FIG. 2, the bracket 36 not only supports the pump 22, but also indirectly supports the reservoir 20 from beneath. The reservoir 20 is, therefore, free to sag downward and bulge sideways. Such free sagging/bulging is conducive to the formation of folds and corners in which liquid product can be trapped as the reservoir 20 collapses in upon itself.
FIG. 3 renders a longitudinal cross-sectional view of a dispenser 10 according to an embodiment of the current invention. As in the example shown in FIG. 1, the dispenser 10 includes a housing 12 for removably accommodating an assembly C comprising a collapsible reservoir 20 and a pump 22 that is connected to the reservoir 20. In addition, the dispenser 10 of FIG. 3 includes tensioning means T, the operation of which will now be explained.
The reservoir 20 in the current case is a plastic foil bag includes two major opposing surfaces 20 a that are sealed together at a first extremity (head) E1 and a second extremity (foot) E2, and are joined at the sides by an arrangement of foil sheet parts 20 b with a central longitudinal folding seam 20 c. Due to this construction, the reservoir 20 may collapse (substantially) flat in a concertina-like manner, whereby the parts 20 a and 20 b fold toward one another, hinging inward about the folding seam 20 c. Consequently, the reservoir 20 has a relatively flat form when empty and a relatively bulged form when at least partially filled, whereby bulging of the reservoir along a first direction (the outward arrows F) occurs as a result of corresponding contraction of the reservoir along a complimentary second direction (the inward arrows G). In a particular example, the plastic foil of the parts 20 a and 20 b may, for example, include polyethene (PE), polyamide (PA), polyethene terephthalate (PET), polypropene (PP), ethene-vinyl alcohol polymer (EVOH), or combinations (e.g., sandwiches/laminates) of these materials.
The housing 12 includes tensioning means T for applying an external force to the reservoir 20, which force is tensile along the second direction G. By tensing/stretching the reservoir 20 along the direction G (which amounts to pulling extremities E1 and E2 away from one another, i.e., opposite to the indicated arrows G), the outward bulging of the reservoir in the direction of the arrows F is counteracted. As here depicted, the tensioning means T include suspending means 46 for suspending the reservoir 20 so that it hangs/dangles in the housing 12 under the force of gravity; this contrasts with the situation in FIG. 2, in which the reservoir 20 is supported from beneath. Such hanging suspension of the reservoir 20 under its own weight applies a basic tensile force to the reservoir along the second direction G.
As here depicted, the suspending means 46 take the form of a lug in the housing 12, which lug cooperates with (for example) a hook or a hole provided through the sealed extremities of the faces 20 a of the bag 20. However, as an alternative to such an arrangement, the skilled artisan could also easily conceive other suspending means 46 for suspending the reservoir 20, e.g., using clamping jaws, Velcro, adhesive tape, etc. In general, suspending the reservoir 20 along a line (or a distribution of points) has been observed to give more satisfactory results than suspending the reservoir 20 at a single point (or relatively confined area).
In a refinement of the tensioning means T, the suspending means 46 are provided on the cylindrical surface of a drum 40 that can be rotated about a substantially horizontal axis; in the drawing, the drum 40 is fitted on a substantially horizontal axle 42 provided at one end of an arm 44 that extends outward from the back wall 34 of the housing 12. This drum 40 is rotationally/torsionally biased about the axle 42 (using biasing means that have not been depicted in the figure, but that may include a spiral spring or elastic belt, for example) such that the drum wants to roll in the direction of the arrow H (first rotational sense), which is opposite to the moment (in the second rotational sense) exerted on the drum 42 by the weight of the reservoir 20 (including the weight of any liquid product within the reservoir 20). This has two effects, namely:

- it results in an additional tensioning/stretching force on the reservoir 20 along the second direction G;
- it causes the upper portion of the reservoir 20 to be rolled onto the drum 40 as the reservoir 20 empties, thus taking up the slack that arises as a result of the relaxation of the reservoir along the second direction G, and, consequently, ensuring that the second/lower extremity E2 of the reservoir 20 remains at a substantially constant horizontal level in the housing 12.

At the second/lower extremity E2 of the reservoir 20 is a collar 21 a providing flow access to the inside of the reservoir 20. The pump 22 is attached to the reservoir 20 at this point (e.g., by clamping) so that an inlet duct 21 b of the pump 22 fits into the collar 21 a (see, e.g., the construction set forth for this purpose in the abovementioned U.S. Pat. No. 5,732,853, the entire disclosure of which is hereby incorporated herein, in its entirety, by this reference). Within the pump 22 is a non-return liquid inlet valve 23 for admitting liquid product into the pump 22 from the reservoir 20, the influx of liquid product through the valve 23 occurring along a flow axis I. With the aid of clamping means 13 provided as part of the housing 12, the pump 22 is held/postured in such a manner that the flow axis I is substantially horizontal.
The inventor has observed that, in the case of relatively viscous liquid products (e.g., products with a viscosity in the range 10³to 10⁵centipoise: see above), the distance H between the liquid inlet valve 23 of the pump 22 and the point 21 a at which the pump 22 is attached to the reservoir 20 is preferably kept as short as possible; in the current case, this implies that the inlet duct 21 b should have a minimum (practicable) length. In this manner, pressure loss in the head H is kept to a minimum, so that the ability of the pump 22 to suck liquid product out of the reservoir 20 is optimized.
It should be noted that the pump 22 shown in FIG. 3 may also be tilted upward from horizontal. If one decides to use the pump 22 at such an above-horizontal angle, then one should generally ensure that:

the lower part of the reservoir 20 in the vicinity of the second extremity E2 is not kinked, which might cause an undesirable restriction in the flow of liquid product out of the reservoir 20;
the head H referred to in the previous paragraph does not have to be made disadvantageously long in order to accommodate the upward tilt of the pump 22.

As here depicted, the actuating means 14 merely include a cap on the pump 22, which cap can be operated by hand. However, more elaborate actuating means can also be employed as an alternative to this simple arrangement, as set forth above.
A further embodiment of a dispenser 10 according to the present invention is identical to that described above with respect to FIG. 3, except as regards certain details of the tensioning means T. In this further embodiment, instead of rotationally biasing the drum 40, it can instead be used as a rotating pulley or a static sliding guide, and a spring or hanging counterweight (neither of which is depicted) can be used to tension the extremity E1 of the reservoir over this pulley/guide. Alternatively, instead of using a drum 40, the reservoir 20 can be hung from a spring or other resilient member (not depicted), which will pull the reservoir 20 upward as it becomes lighter (due to removal of liquid product therefrom).
Although the foregoing description contains many specifics, these should not be construed as limiting the scope of the present invention, but merely as providing illustrations of some of the presently preferred embodiments. Similarly, other embodiments may be devised which do not depart from the spirit or scope of the present invention. Features from different embodiments may be employed in combination. The scope of the invention is, therefore, indicated and limited only by the appended claims and their legal equivalents, rather than by the foregoing description. All additions, deletions and modifications to the invention as disclosed herein which fall within the meaning and scope of the claims are to be embraced thereby.

Claims

1. A dispenser for dispensing a fluid product, comprising:

an assembly, comprising:

a collapsible reservoir, for containing a liquid product, the collapsible reservoir having a relatively flat form when empty and a relatively bulged form when at least partially filled, whereby bulging of the reservoir along a first direction occurs as a result of corresponding contraction of the reservoir along a complementary second direction;

a pump, connected to the reservoir, for dispensing a fluid product using the liquid product as an input, whereby:

when the assembly is accommodated in the housing, the pump is located at the underside of the reservoir; and

the liquid product is withdrawn by the pump from the reservoir without a substantial gas flow back into the reservoir; and

a housing for removably accommodating the assembly, the housing comprising:

tensioning means for applying an external force to the reservoir which is tensile along the second direction; and

actuating means for actuating the pump so as to dispense fluid from the pump to the exterior of the assembly.

2. The dispenser according to claim 1, wherein the tensioning means comprise suspending means for suspending the reservoir by a first extremity so that it hangs under the force of gravity, the pump being connectable to a second extremity of the reservoir located opposite the first extremity.

3. The dispenser according to claim 2, wherein the suspending means comprise a drum that can be rotated about a substantially horizontal axis and that is rotationally biased in a first rotational sense, the reservoir being hung on the drum in such a manner that the weight of the reservoir exerts a moment on the drum in a second rotational sense opposite to the first rotational sense.

4. The dispenser according to claim 1, wherein:

the pump comprises a liquid inlet valve for admitting liquid product into the pump from the reservoir, the influx of liquid product through the valve occurring along a flow axis;

the housing comprises clamping means for clamping the pump in a given posture, whereby the pump is thus postured by the clamping means that the flow axis is substantially horizontal.

5. The dispenser according to claim 1, wherein the actuating means comprise at least one of:

an actuating organ movably connected to the housing and serving to cooperate with said pump, whereby the pump can be actuated by manually moving the actuating organ;

a detector, for detecting that a member onto which fluid is to be dispensed has been offered to a dispensing head of the pump; and

an electric actuator, for actuating the pump on the basis of a signal output from the detector.

6. The dispenser according to claim 1, comprising mounting means for mounting the housing to a surface.

7. The dispenser according to claim 1, wherein the liquid product is selected from the group comprising soap, shower gel, detergent, exfoliating scrub, and mixtures of these substances.

8. A housing of a fluid product dispenser for removably accommodating an assembly including a collapsible reservoir of the fluid product dispenser, the housing comprising:

tensioning means for applying an external force to the collapsible reservoir to counteract compression of the collapsible reservoir as fluid product is removed from the collapsible reservoir.

9. The housing according to claim 8, wherein the tensioning means comprise suspending means for suspending the reservoir by a first extremity so that it hangs under the force of gravity, a pump being connectable to a second extremity of the reservoir located opposite the first extremity.

10. The dispenser according to claim 9, wherein the suspending means comprise a drum that can be rotated about a substantially horizontal axis and that is rotationally biased in a first rotational sense, the reservoir being hung on the drum in such a manner that the weight of the reservoir exerts a moment on the drum in a second rotational sense opposite to the first rotational sense.

11. A housing of a fluid product dispenser for removably accommodating an assembly including a collapsible reservoir of the fluid product dispenser, the housing comprising:

a tensioning element configured to apply an external force to the collapsible reservoir to counteract compression of the collapsible reservoir as fluid product is removed from the collapsible reservoir.

12. The housing according to claim 11, wherein the tensioning element comprises suspending means for suspending the reservoir by a first extremity so that it hangs under the force of gravity, the pump being connectable to a second extremity of the reservoir located opposite the first extremity.

13. The dispenser according to claim 12, wherein the suspending means comprise a drum that can be rotated about a substantially horizontal axis and that is rotationally biased in a first rotational sense, the reservoir being hung on the drum in such a manner that the weight of the reservoir exerts a moment on the drum in a second rotational sense opposite to the first rotational sense.