Note: Descriptions are shown in the official language in which they were submitted.
CA 02233l4l l998-03-26
W O 97/15Z23 PCTAEP96/04435
LIOUID DISPENSER
Technical field of the invention
The present invention is concerned with a dispenser of the
5 kind for delivering aliquots of a liquid product from a
reservoir by means of a pump which is m~nll~lly operable. Such
dispensers are often used in washrooms etc. for dispensing
small amounts of a liquid soap product for hand washing pur-
poses .
BACKGROUND AND PRIOR ART
Various dispensers of the above-indicated kind have been
described in the literature. For example, the US-patent
4,256,242 (Christine) discloses a liquis soap dispenser
15 comprising a housing, a collapsible bag for holding the
liquid soap product and an operating lever or handle for
actuating controlled amounts of soap from the bag.
The collapsible bag is connected to an outlet by means of a
flexible conduit which comprises a pump. These known types of
20 dispensers offer hygiene and ease of handling for the user.
However, one problem with this kind of dispensers resides in
the fact that only a small amount of liquid soap may be
dispensed at the time due to the limited capacity of the
peristaltic type of pump applied. The amount is usually not
25 more than 0.5 to 1 ml.
Another problem which has been encountered with this type of
pump is related to the way the pump operates: after the pump
has been actuated the pump tubing recovers to its original
30 shape and thereby sucks in liquid product for the next shot.
This sucking action of the tubing is directly related to the
memory properties thereof which could decline depending on
the material of the tubing and the operating time o~ the
pump. As a consequence, the dosage of the pump per shot could
35 decline.
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W O 97/15223 PCTrEP96/04435
In order to overcome this problem, it has been proposed in
the British patent application 2 103 296 to provide the
dispenser with a bellow pump Eitted with an external spring.
5 As a result o~ this spring, the recovery properties of~ the
bellow pump can be optimized to such extent that even liquid
products o~ high viscosity can be satis~actorily applied in
this dispenser. For reasons o~ easy handling, the dispenser
disclosed by this document comprises a disposable reEill
10 which comprises a reservoir and the bellow pump.
However, the disclosed dispenser is a rather specif~ic one in
that it can only be activated by electromagnetic means.
Another type of~ dispenser also comprising a disposable re~ill
15 package including a reservoir f~itted with a bellow pump, is
disclosed by W094/07113. The dispenser disclosed by this
document can be simply constructed, is m~nll~lly operable and
can be easily reEilled. However, it has been observed that
the discharge tube o~ the bellow pump present in this
20 dispenser can clog with liquid products which are prone to
dry out in use. As an example o~ such products, thickened
alcohol gels may be mentioned.
It has now surprisingly been f~ound that this problem can be
25 overcome by applying the dispenser o~ the present invention.
Definition of~ the invention
Accordingly, the present invention provides a dispenser for
delivering aliquots o~ a liquid product comprising a housing
30 (1) and a disposable rei~ill package which is positioned
inside the housing and comprises a collapsible reservoir (2)
for the liquid product ~itted with a bellow pump (3), whereby
the bellow pump comprises a product inlet valve and a product
outlet valve and is m~nll~lly operable via indirect actuating
35 means (10,11), and whereby the housing is provided with a
narrow opening (9) into which a correspondingly shaped
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W O 97/15223 PCTAEP96/04435
portion of the bellow pump located near the outlet valve
thereof, can be detachably secured, characterised in that the
bellow pump (3) iS equipped with a discharge tube (8) having
an internal flow channel of which the diameter at the outlet
5 is at least 1.2 times larger than at the inlet.
The present invention also provides a disposable refill
package suitable for use in a dispenser according to the
invention, comprising a collapsible reservoir (2) filled with
a liquid product and attached thereto a bellow pump (3)
10 provided with a narrow portion (9) which can be detachably
secured into a correspondingly shaped opening located in the
housing (1) of the dispenser, characterised in that the
bellow pump (3) is equipped with a discharge tube (8) having
an internal flow ch~nn~l of which the diameter at the outlet
15 is at least 1.2 times larger than at the inlet.
Detailed description of the invention
Since the internal diameter of the discharge tube of the
bellow pump is wider at the outlet than at the inlet, said
20 tube widens in the direction of liquid flow. As a
consequence, any plug of dried out liquid product present
inside the tube breaks up easily whenever the dispenser is
operated after a long stand-still period.
Furthermore, in order to produce a discharge tube of the
25 present invention a st~n~d discharge tube needs to be
modified by removing material therof. As a result, the
discharge tube becomes more flexible, thus adding to the
ease, by which any blockage present therein can be removed.
In order to secure smooth flow of liquid, in particular
liquid of increased viscosity, the internal diameter of the
discharge tube at the inlet thereof is preferably larger than
1 mm. Furthermore, the internal diameter at the outlet of the
discharge tube is preferably 1.5 times larger than at the
inlet.
CA 02233141 1998-03-26
W O 97/15223 PCT~E~96/01
On the other hand, the discharge tube o~ the present
invention desirably comprises a ~low ~h~nn~l having an
internal opening with a diameter o~ less than 3 mm. The
advantage o~ this type o~ discharge tube is that the ~low
5 rate o~ the liquid product ~lowing out o~ the bellow pump
during each dose, is increased due to the narrow internal
opening, which proved to have a sel~-cleaning ef~ect on the
~low ch~nn~l. The possibility o~ bacterial growth entering
the valve is thereby ~urther d;m;n;shed.
Pre~erably, the discharge tube according to the invention
is made o~ plastic material such as polyethylene,
polypropylene, and PVC.
Also, the reservoir which is part o~ the disposable re~ill
15 package applied in the dispensing system o~ the present
invention, is preferably made o~ these types of plastic
material. For reasons o~ convenience and in order to reduce
the risk that the liquid to be dispensed is contAm;n~ted when
installing a new re~ill, the re~ill is made o~ one piece.
The bellow pump to which the discharge tube is attached,
comprises a liquid inlet valve and a liquid outlet valve
which are respectively closed and opened by mAnl~lly operable
actuating means during each dose.
25 Immediately after each dose, when the liquid outlet valve is
closed, the liquid inlet valve is opened by the suction
action of the bellow when it recovers to its original
position. As a result, ~ull liquid commlln;cation with the
reservoir is achieved and the internal volume o~ the bellow
30 pump is re~illed by liquid sucked in ~rom out o~ the reser-
voir.
As a consequence o~ this action o~ the liquid inlet and
outlet valves present in the bellow pump during and im-
mediately a~ter each dose, no air can enter the internal
35 volume o~ bellow pump and reservoir and the risk of con-
tamination o~ the liquid to be dispensed is m;nim; zed.
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PCT~EP9CI~
W O 97/15223
The material of the bellow pump i5 preferably such that the
suction action of the bellow pump is kept more or less
constant, also after many dosages have been done.
When the dispenser is used for dispensing more viscous types
5 of liquid, the bellow pump is preferably equipped with an
external spring. This spring ensures that constant dosage
volumes are obtained during the operating life of the
dispenser even with highly viscous liquids because it forces
the bellow pump back into its original shape after each dose.
In order to ensure that the refill package is easily and
securely fitted in the housing of the dispenser, the housing
is provided with a narrow opening into which a correspon-
dingly shaped portion of the bellow pump located near the
15 outlet valve thereof can be detachably secured. Furthermore,
this narrow opening ensures that only refill packs cont~;n~ng
the desired type of liquid product will be mounted in the
dispenser, because other packs cont~;n;ng different products
simply will not fit.
20 This narrow opening is desirably in the form of a slit having
a width of less than 5 mm, preferably less than 2 mm.
For reasons of ease of handling, the dispenser of the present
invention is equipped with m~n~ ly operable indirect
25 actuating means. These may practically comprise a push rod
which i9 coupled to the bellow pump via a tilting table.
The internal volume of the reservoir gradually decreases when
liquid product is taken out and dispensed. When the reservoir
30 is pumped empty, underpressure is created and, as a conse-
quence, the bellow of the pump will be kept in a collapsed
position. The resulting reduction in length of the bellow
pump can be used as an empty pack indicator.
35 Dispensers comprising a bellow pump with a dosing capacity of
from about 0.1 to 10 ml are very suitable for use in
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WO 97/15223 PCT/EP96/04435
washrooms. This type of dispensers having a dosing capacity c
in the mentioned range can be made much more compact than
dispensers with peristaltic or plunger pumps with the same
dosing capacity.
The invention wil now be better explained by way of the
preferred embodiment shown in the accompanying drawings of
which:
Figure 1 shows cross-sectional views of a dispenser according
10 to the invention including a housing, a collapsible reservoir
and a bellow pump, whereby the bellow pump is not activated
(a) respectively activated (b);
Figure 2 shows a crogs-gectional view o~ the bellow pump,
including an inlet and outlet valve, and a discharge tube.
In Figure 1, a housing (1) is ghown comprising a refill
package which comprises a reservoir (2) and a bellow pump
(3). The dispenser can be m~n~ ly operated with indirect ac-
tuating means comprising a push rod (10) which is coupled to
20 a tilting table (11) which in turn ig connected to the bellow
pump (3).
As shown in Figure 1, a narrow portion (9) is connected to
the bellow pump (3) which portion is used for securely
positioning the refill package in the housing of the
25 dispenser. Furthermore, the bellow pump is provided with a
discharge tube (8) which comprises a flow ch~nnel having a
narrow internal opening of which the cross-section at the
outlet is wider than at the inlet of said discharge tube.
It can also be noticed that an external spring (12) is
30 present between tilting table (11) and the housing. This
spring ensures that constant volumes are dosed even when
applying high viscosity liquids.
Figure 2 shows a bellow pump provided with an inlet valve
35 (4), an outlet valve (5) and a bellow section (6). Because
the internal volume of the bellow pump contains the liquid to
CA 0223314 1 1998 - 03 - 26
PCT/~ 5
W097/15223
be dispensed during the next dose, the bellow pump functions
as a type of dosing section. It can further be seen that the
discharge tube (8) of the bellow pump comprises an internal
~low ch~nn~l of which the diameter widens from l.6 mm at the
5 inlet to 2.5 mm at the outlet, thus ensuring favourable
operation o~ the dispenser even when using viscous liquids
which are prone to dry out during stand-still periods.
It is ~mph~sized that the dispenser shown in the Figures
lO illustrates only a pre~erred embodiment of the invention and
that various constructional alternatives will be immediately
evident to the man skilled in the art, without departing from
the scope o~ the present invention.
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