[0001] The present invention is concerned with a pump of the kind for delivering aliquots
of liquid from a reservoir, the pump comprising a conduit which comprises one end
for receiving liquid from the reservoir, a second end provided with a valve through
which the liquid is expelled, and a flexible portion between the first and second
ends for being compressed by a compressing mechanism of a dispensing device, thereby
to close the conduit at a pinch position in the region of said one end and for then
being compressed by the mechanism, between the pinch position and the valve, to create
excess pressure of liquid which is thus expelled through said valve.
[0002] Such pumps are often used integrally with a flexible bag filled with liquid soap,
for placing in soap dispensers in washrooms etc.
[0003] In known pumps of this kind, the valve is of a conventional type often consisting
of a spring-loaded ball which is urged against an orifice. Excess pressure in the
conduit forces the ball away from the orifice against spring-bias. A problem with
this kind of valve is that it provides insufficient protection against entry of contaminant
micro-organisms which can enter the reservoir via the conduit. A subsidiary disadvantage
is that there is also a tendency for such valves to leak when used with low viscosity
liquids.
[0004] We have now found that these disadvantages can be overcome if the valve comprises
a flexible collar overlying an externally communicating channel member and in part
sealed thereto to prevent liquid escape, the channel member comprising an inlet covered
by the collar which is substantially sealed thereagainst until the excess liquid pressure
is created. Protection against entry of micro-organisms is especially enhanced by
providing a more tortuous path by means of the channel member being substantially
cylindrical and comprising an axial channel, one end of which is a liquid outlet and
the other end communicating with a first end of one or more radial channels, the second
end or ends of said radial channels constituting said channel member inlet. It is
especially convenient if the conduit is a tube which is flexible along substantially
the whole of its length, the second end thereof consistuting the flexible collar of
the valve, which collar is thereby integral with the remainder of the conduit.
[0005] It is easiest to ensure sealing of part of the collar to the channel member if the
latter is provided with a flange to which the flexible collar is attached, preferably
at its tip.
[0006] The present invention further extends to such pumps when attached to a reservoir,
e.g. filled with a liquid product such as a liquid soap. Preferably, such a reservoir
comprises a flexible bag.
[0007] Yet again, the invention encompasses such a pump attached to a reservoir, wherein
the reservoir with pump is fitted to a dispensing device such that the compressing
member thereof can act on the flexible portion of the conduit to deliver aliquots
of liquid upon activation of said compressing member.
[0008] The invention will now be better explained by way of the following preferred embodiment,
and with reference to the accompanying drawings, in which:
Fig. 1 is a section view of a dispenser with a flexible bag reservoir, with a pump
according to the prior art.
Fig. 2 shows an enlarged perspective cut-away view of the valve of the pump shown
in Fig. 1, in the closed position.
Fig. 3 shows a dispenser, reservoir and pump according to Fig. 1 but with the lever
partly actuated.
Fig. 4 shows the dispenser, reservoir and pump of Fig. 1 and 3, with the lever fully
actuated.
Fig. 5 shows an enlarged perspective cut-away view of the valve of the pump in Fig.
1, in the open position.
Fig. 6 shows a perspective cut-away view of a valve for use according to the invention
in the apparatus shown in Fig. 1, 3 and 4, in the closed position.
Fig. 7 shows a perspective cut-away view of the valve shown in Fig. 6 but in the open
position.
[0009] A dispenser (1) for liquid soap comprises a casing (3) having a front wall (5) and
a back wall (7). The dispenser also comprises a lever (9) pivotally mounted on hinge
(11). Attached to the lever is a compressing mechanism (13) which comprises a finger
(15) pivotally mounted at end (16) by hinge (17) and attached at the other end (18)
by a compression spring (19). At that other end, the finger also defines an elbow
(21).
[0010] Mounted in the dispenser is a flexible bag reservoir (23) containing liquid soap
(25). A collar (27) connects the reservoir to a pump (29). The reservoir and pump
are mounted in the dispenser by means of the collar being received in a slotted shelf
(31) of the dispenser which thereby supports the reservoir.
[0011] The pump comprises a flexible tube (33) which at one end (34) is arranged to receive
liquid from the reservoir through the collar and at the other end is provided with
valve (36).
[0012] The valve (36) is a conventional ball valve comprising a chamber (37) in which is
located a ball (39) which is urged by a compression spring (40) against an orifice
(41). The chamber is also provided with an outlet nozzle (43) through which the liquid
soap is to be dispensed.
[0013] The tip (45) of the tube is sealed to the valve around annular flange (47) to prevent
unwanted escape of liquids. With the lever in the rest position, the elbow (21) of
the finger of the compressing mechanism just impinges on the flexible tube and compresses
it very slightly. Referring now to Fig. 3, it will be seen that when the lever (9)
is partly actuated by pulling in the direction of the arrow (A), the elbow (21) first
closes the tube at a pinch position (49) just below the first end of the flexible
tube. This action traps a quantity of liquid soap (51) and the slight excess pressure
in the tube below the pinch position begins to move the ball away from the valve orifice
so that liquid soap (53) begins to enter the chamber.
[0014] Finally, as shown in Fig. 4 and Fig. 5, when the lever is pulled forward to its fullest
extent in the direction of arrow (B), the flexible tube is compressed along the entire
length of the finger and the liquid previously trapped below the pinch position is
ejected at (55). Referring now to Fig. 6 and 7, in accordance with the invention,
the valve (36) is replaced by an alternative valve (57). This valve comprises a channel
member (59) inside which is an axial channel (61) connecting an outlet nozzle (63),
through which the soap is expelled, and a radial channel (65) which has an inlet (67).
A collar (69) overlies the alternative valve at its upper end, and the tip of the
flexible tube (33) constitutes a collar (69) of the valve, which in Fig. 6 (corresponding
to the lever of the dispenser being in the rest position) is sealed against the inlet.
The tip (71) of the tube/collar is sealed against an annular flange (73) to prevent
escape of liquid. According to the invention, when the lever of the dispenser is squeezed
through the positions shown in Fig. 3 and 4, the excess pressure in the flexible tube
causes the collar to bulge so as to uncover the inlet (67), thereby expelling liquid
through the outlet nozzle.
1. A pump for delivering aliquots of liquid from a reservoir, the pump comprising
a conduit which comprises one end for receiving liquid from the reservoir, a second
end provided with a valve through which the liquid is expelled, and a flexible portion
between the first and second ends for being compressed by a compressing mechanism
of a dispensing device, thereby to close the conduit at a pinch position in the region
of said one end and for then being compressed by the mechanism, between the pinch
position and the valve, to create excess pressure of liquid which is thus expelled
through said valve, characterised in that the valve comprises a flexible collar overlying
an externally communicating channel member and in part sealed thereto to prevent liquid
escape, the channel member comprising an inlet covered by the collar which is substantially
sealed thereagainst until the excess liquid pressure is created.
2. A pump according to Claim 1, further characterised in that the channel member is
substantially cylindrical and comprises an axial channel, one end of which is a liquid
outlet and the other end communicating with a first end of one or more radial channels,
the second end or ends of said radial channels constituting said channel member inlet.
3. A pump according to either preceding Claim, further characterised in that the conduit
is a tube which is flexible along substantially the whole of its length, the second
end thereof constituting the flexible collar of the valve, which collar is thereby
integral with the remainder of the conduit.
4. A pump according to any preceding Claim, further characterised in that the channel
member is provided with a flange to which the flexible collar is sealed.
5. A pump according to any preceding Claim, when attached to a reservoir.
6. A pump according to Claim 5, wherein the reservoir comprises a flexible bag.
7. A pump according to Claim 5 or Claim 6, wherein the reservoir and pump are fitted
to a dispensing device such that the compressing member thereof can act on the flexible
portion of the conduit to deliver aliquots of liquid upon actuation of said compressing
member.