Dispenser

The present invention relates to a dispenser for liquid products and particularly, but not exclusively, to a wall mounted soap dispenser.

Wall mounted soap dispensers typically comprise a housing secured to a wall and a disposable refill pack. It is preferable that the dispensing mechanism, normally in the form of some sort of pump, also forms part of the refill pack such that the pump and any associated valves are changed with the refill pack. Thus, if either the pump or any the valves fail they will simply be replaced when the next refill pack is inserted.

The problem with such disposable refill packs is that having the pumps and associated components as part of the refill pack increases the price of the refill pack. There is therefore a need for a dispenser with a dispensing mechanism which is very cheap to manufacture but which at the same time functions reliably and which after use does not drip onto washroom surfaces.

According to the present invention there is provided a product dispenser comprising a reservoir for a liquid product, an outlet nozzle and a pump chamber in fluid connection with the reservoir and the outlet nozzle, a non-return inlet valve located between the chamber and the reservoir permitting fluid to only flow from the reservoir into the chamber and a non-return outlet valve located in the nozzle, wherein the dispenser operation is arranged to decrease the volume of the chamber forcing liquid in the chamber out of the outlet valve and to subsequently allow expansion of the chamber to draw liquid into the chamber from the reservoir, wherein the outlet nozzle is in the form of a tube in which the outlet valve is located, the outlet valve being formed of a resilient material and arranged to be inserted in the outlet nozzle, the outlet valve having at least one passage extending from an outlet of the outlet valve to a wall of the outlet valve adjacent the outlet nozzle, wherein the resilient properties of the outlet valve act to press at least the part of the wall forming a mouth of the inlet of the passage into contact with the outlet nozzle to seal the mouth with

nozzle, wherein the nozzle and outlet valve are dimensioned such that, when the dispenser is in use, pressurised liquid in the nozzle acts to distort the outlet valve and permit liquid to pass through the passage to the outlet of the valve and when the pressure in the nozzle is reduced to less than ambient pressure causes the mouth of the passage into contact with nozzle.

The present invention is particularly applicable to soap dispensers where the liquid product may be anything from a low viscosity water-like gel to a high viscosity barrier cream.

Having a dispenser with a pump chamber, in which the volume may be varied by any appropriate means, with a non-returned valve on the inlet and outlet provides a dispenser pump with a minimum of components. The use of an outlet valve in accordance with the present invention provides a valve with a single moveable component, which component can be inserted directly in the outlet of the nozzle, such that the outlet valve forms the outlet of the dispenser. This reduces the amount of residual product downstream of the outlet valve and therefore minimises the amount of product which can drip from the dispenser after use. Furthermore, the outlet valve is inexpensive to manufacture, comprising only a single component and the wall of the outlet nozzle as a seal for the passage to the outlet of the valve.

The outlet valve preferably faces downwards and the at least one passage and outlet of the outlet valve are dimensioned such that for a particular liquid type, with which the dispenser is intended to be used, the mass of the volume of liquid retained in the at least one passage and the outlet of the outlet valve is insufficient to overcome the surface tension retaining the liquid in the outlet of the outlet valve so that the liquid will not drip from the outlet valve. In this manner, the very small residual amount of liquid remaining in the valve after a dispensing cycle is not sufficient to drip from the dispenser.

Preferably, the outlet of the outlet valve is greater in cross-section than the mouth of

the inlet of the passage through the outlet valve. This providing a way of reducing the velocity of the liquid as it passes through the point in which the valve closes. This ensures that liquid being dispensed is not squirted at high speed from the dispenser, which can result in unnecessary spillage. The arrangement of the present invention enables this to be achieved without having an excess volume of liquid downstream of the point at which the valve seals, because this may be undesirable if it subsequently causes the dispenser to drip after completion of a dispensing cycle.

Advantageously, the outlet valve, at least in part, is in the form of a vertical tube closed at an upper end with the lower open end forming the outlet of the outlet valve, with the at least one passage extending through the wall of the tube; wherein the nozzle of the dispenser is also in form of a vertical tube and the outlet valve is a press fit in an opening at the bottom of the nozzle, the outlet valve being arranged to remain sealed with the nozzle at a point below the at least one passage, thus liquid can only be released from the nozzle via the at least one passage. This provides a very simply way of fitting the valve to the outlet nozzle of a dispenser and ensures that liquid to be dispensed has to pass through the passage of the valve and thus via the sealing surface formed around the mouth of the inlet of the passage.

The nozzle and outlet valve may be dimensioned such as to provide a tapered space between an inner wall of the nozzle and the wall of the outlet valve at a point above the at least one passage. Pressurised fluid in the nozzle can then act on the wall of the outlet valve forming the tapered space to distort the wall of the outlet valve, forcing the mouth of the passage away from the inner wall of the nozzle and permitting liquid to exit the nozzle via the passage.

This arrangement ensures that even if liquid in the nozzle should dry out, pressure inside the nozzle will ensure the valve opens, thus providing a particularly reliable arrangement of valve.

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The outlet nozzle is preferably mounted vertically with the outlet valve located at the bottom thereof, the outlet valve and nozzle being dimensioned such that the outlet valve engages with an inner wall of the outlet nozzle at a point above the mouth of the at least one passage, such that pressure of liquid in the nozzle does not axially compress the outlet valve.

If the valve is arranged in the above manner, then even if excessive pressure is built up in the pump chamber, the outlet valve will not be compressed in the axial direction, which could result in the valve expanding radially and prevent the valve from operating.

A particularly simple arrangement for a pump chamber comprises a cylinder and a cylindrical piston slidably mounted within and sealed with the cylinder, wherein the piston and cylinder are mounted vertically with the lower one of the piston or cylinder forming the outlet nozzle at the lower end of which the outlet valve is located. This further minimises the number of components. The pump chamber may then be actuated by simply lifting the outlet nozzle, either directly by the user exerting a vertical upward force on the outlet nozzle, or by means of an actuating mechanism mounted in a housing of the dispenser.

The present invention may advantageously be employed in a dispenser comprising a wall mounted housing and a replaceable refill pack, wherein the refill pack comprises the reservoir, pump chamber and non-return inlet valve, non-return outlet valve and nozzle. Here, all the components which are likely to fail are replaced as part of the refill pack. Furthermore, these components may be tailored to suit the particular product within the refill pack.

One embodiment of the present invention will now be described, by way of example only, with reference to the accompanying figures, of which:

Figure 1 is a cross-section through a dispenser mechanism, indicated generally as 1, of the dispenser 2 of Figure 9; Figure 2 is an expanded view of section A of Figure 1 ;

Figure 3 is a section through the outlet valve of the dispenser mechanism of Figure 1 ;

Figure 4 is a plan view along line D-D of Figure 3;

Figure 5 is a plan view along the line B-B of Figure 3; Figure 6 is a plan view along the line C-C of Figure 3;

Figures 7 and 8 correspond to Figures 1 and 2 but depict the dispensing mechanism is a fully primed state at the start of a dispensing cycle;

Figure 9 is a partially cut-away side elevation of the dispenser incorporating the dispensing mechanism of Figures 7 and 8; Figures 10, 11 and 12 correspond to Figures 7, 8 and 9 but depict the dispenser at completion of a dosing stroke; and

Figures 13, 14 and 15 correspond to Figures 7, 8 and 9 but illustrate the components of the dispenser at the start of its priming stroke.

Referring now to Figure 1, the dispenser mechanism, illustrated generally as 1, comprises a pump chamber 2 formed by a pump cylinder 3 and outlet nozzle 4, the latter in the form of a piston slidably mounted within the cylinder 3 and sealed to the cylinder by O- ring seal 5, maintained in place by retaining ring 6. The cylinder 3 has an extended moulding 7 over which a reservoir 8 (shown in Figure 9) seals.

When outlet nozzle 4 is displaced in the direction of arrow 9, fluid is drawn into the pump chamber 2 through a non-return inlet valve 10, which allows fluid to pass from the reservoir 8 in the direction of arrows 11.

The dispenser mechanism of Figure 1 is actuated by exerting the force, represented by arrow 12 on flange 13 mounted on the lower section of outlet nozzle 4.

This same flange 13 is also used to raise the outlet nozzle 4, which causes liquid within the chamber 2 to be pressurised and forced past non-return valve 14. Figure 2 is an enlarged cross-section of the portion of the valve appearing in section A of Figure 1 and the

components of the outlet valve 14 will now be described, with reference to Figures 2 to 6.

As most clearly shown in Figures 2 and 3, the outlet valve 14 comprises the lower portion of the tubular outlet nozzle 4 and an insert 15. The insert 15 is formed of a soft resilient material such as a rubber or a thermoplastic elastomer.

The lower portion of the outlet nozzle 4 has a circumferential rebate 16 towards the lowermost edge of its inner wall and above that a protrusion 26 which is chamfered on its upper and lower edges. Above the protrusion 26 and extending from both the protrusion 26 and the inner surface of the wall of the outlet nozzle, are a plurality of radially extending spars 18. These can be most clearly seen from the planar views of Figure 4 and Figure 5 taken along the lines D-D and B-B of Figure 3 respectively. Here it is seen that the spars 18 define recesses 17 therebetween.

Resilient insert 15 is inserted into the bottom of the outlet nozzle 4 in the manner shown, until circumferential ridge 19 towards the bottom edge of the insert 15 engages in rebate 16, sealing with the rebate. The insert 16 is substantially in the form of a vertically mounted tube having a central outlet passage 20. The outlet passage 20 is sealed at its upper end by conical head portion 21 of the insert 15. The outer wall 22 of the insert 15 is waisted towards a mid-portion, as shown, to provide a recess 23 under the edge of the conical head portion 21. When fully inserted, this recess 23 permits the edge of the conical head portion 21 to engage over the top of the spars 18, as shown in Figure 3. This prevents the insert 15 being ejected from outlet nozzle 4 by pressure exerted by liquid in the pump chamber 2, but allows the liquid to flow between the inner wall of the outlet nozzle and the edge of the conical head portion 21 into the recesses 19 between the spars 18. The liquid can then flow to the small tapered space 24 formed around the waisted region of the insert 15.

As most clearly from Figures 3 and 6, the insert has a plurality of radial passages 25 extending from the outer surface 22 of the insert 15 to the central outlet passage 20. The

region of the wall 22 of the insert 15 around each outlet passage 25 defines a mouth 26 of the passage 25. Because of the dimensions of the insert 15 relative to the profiled inner surface of the nozzle 4, in the absence of any pressure differentials, the resilient nature of the inserts closes the passage 25 at the mouth 26 thereof.

Referring now to Figures 7, 8 and 9, Figure 9 depicts a dispenser 38 comprising reservoir 8 and the dispensing mechanism 1 forming a replaceable disposable insert. The dispenser 38 is seen in its primed state prior to dispensing with an actuator handle 28 fully retracted as indicated by arrow 29 of Figure 9. The outlet nozzle 4 of the dispenser mechanism 1 (shown in Figures 7 and 8) is fully retracted to its maximum downward position, as indicated in Figure 7 and represented by arrows 30 and 31. Arrow 31 represents the downward pressure exerted on flange 13 by actuator 28.

As most clearly in Figure 8, the insert 15 of the outlet valve 14, because of its resilient nature seals outlet passages 25, as represented by arrows 32, by sealing the mouth 26 of each passage 25 against the inner wall of the outlet nozzle 4. Thus, the liquid 27 is confined to the remaining portion of the tapered space 24.

Referring now to Figures 10, 11 and 12, here the actuator 28 is depressed by a user in the direction of arrow 33, as shown in Figure 12. This causes the outlet nozzle 4 to be raised in the direction of arrow 35, compressing the liquid therein, which liquid may be a cream soap, liquid soap or similar. Non-return valve 10 prevents the liquid passing back into the reservoir and instead, as the pressure is increased the insert 15 is compressed in its waisted region, as represented by arrows 34 of Figure 11 , permitting the liquid 27 to flow in the direction of arrows 35 and 36, through the now enlarged tapered space 24 through a mouth 26 of a passage 25, into central outlet passage 20.

It is to be noted that the recess 23, engaging with spars 18, prevents the insert from being axially compressed and therefore permits the waisted region to be deformed as described above. This also ensures that excess pressure is not applied, via the body of the

insert 15 itself, on the seal formed by ridge 19 and rebate 16. The cross-section of the central outlet passage 20 is greater than the cross-section of radial passage 25. Thus after exiting the radial passage 25 the fluid flow rate is decreased in the central outlet passage 20 of the valve so that a steady stream 37 of liquid soap is dispensed, as shown in Figure 12. The liquid soap 27 normally only passes through one of the radial passages 25, because once the seal is broken about the mouth of one passage 25, the pressure is reduced sufficiently that the other passages 25 do not open. However, more than one passage may open if excessive pressure is applied to the actuator 28 of Figure 12.

Referring now to Figures 13, 14 and 15, here the dispenser is illustrated after having completed its dispensing stroke, with the actuator 28 now being withdrawn back towards its start position. At this point, the pressure in the pump chamber 2 is reduced and the resilient nature of the insert 15 restores the insert to its original shape, represented by arrows 35 and 36, such that the mouth 26 of each radial passage 25 is again firmly closed against the inner wall of the outlet nozzle 4. At the same time, non-return inlet valve 10 permits fluid to pass from the reservoir 8 in the direction of arrows 37. Thus, the dispenser is returned to its original primed state as illustrated in Figures 7, 8 and 9.

One embodiment of the present invention has been described above by way of example only. However, it will be appreciated that many alternative arrangements are possible which fall within the scope of the appended claims. In particular, the reservoir 8 and dispenser mechanism 1, shown in the preferred embodiments, is a disposable replaceable unit intended as a refill pack for the dispenser 38. However, the invention may equally be applied in non-disposable applications.