GB1586447A

GB1586447A - Manual pump for dispensing container

Info

Publication number: GB1586447A
Application number: GB23415/78A
Authority: GB
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 1977-08-10
Filing date: 1978-05-26
Publication date: 1981-03-18
Also published as: DE2834901A1; FR2400124A1; BE868495A; FR2400124B1

Description

(54) MANUAL PUMP FOR DISPENSING CONTAINER (71) We, L'OREAL, a joint stock company constituted under the French Law of 14, rue Royale, 75008 Paris, France, do hereby declare the invention for which we pray that a patent may be granted to -us, and the method by which it is to be performed, to be particularly described in and by the following statement:- It is known that numerous liquid products, for instance domestic cleaning products or cosmetic products are stored in specialised containers and dispensed by a valve operated manually by the user. To avoid the use of pressurising gases such as chlorofluoroalkanes, which are rejected with a view to ecological reasons, dispensing pumps have been considered which employ a manually operated reciprocating pump action. In particular piston pumps have been proposed allowing a predetermined quantity of liquid to be ejected when the liquid has been pressurised by manual action to a determined precompression level. In this way it is possible to obtain sufficiently finely divided spray jets, and this constitutes an essential quality which is necessary in particular for the dispensing of cosmetic products.

Nevertheless manual piston pumps of the known type are relatively costly because they comprise a number of elements which co-operate mechanically with each other. From the commercial point of view, containers fitted with manual dispensing pumps are in general considered as lost containers and are not recovered when the container is empty so it is highly desirable to have at one's disposal a low cost manual dispensing pump allowing a spray jet to be obtained with the required characteristics. Moreover for the dispensing of products which dry in air the piston pumps are not always very reliable because the dispensed product may dry and jam the piston of the pump.

It is known that in the present state of technology (see for example the British Patent 647,604) there exist manual diaphragm pumps for atomisers whose compression chamber is surrounded by a tube with an elastically deformable wall which is subjected to the action of a device which c2n be operated in a reciprocating manner. At its two ends the compression chamber is closed by an inlet valve communicating with the interior of the associated bottle and, via an outlet valve, with the spray nozzle. The diaphragm pump of the type indicated above has the characteristic of creating a pressure wave with a very gradual build-up, which is not compatible with the type of ejection desirable for cosmetic products. In fact one cannot obtain a sharp ejection of the liquid, since the ejected flow undergoes a very gradual build-up then a decay, both of which are accompanied by splattering. Now for cosmetic products it is desired to obtain a dispensing jet constituted by a cloud of droplets which are sufficiently fine so that it does not give the impression of "wetting" when it is applied to the user's skin.

Moreover United States Patent No. 3,127,845 discloses a diaphragm pump intended for corrosive or volatile liquids at high pressures. The characteristic of such a pump is to allow a sharp discharge of the liquid product since the elastically deformable tube which surrounds the compression chamber is supported in all its zones by a rigid supporting surface. Thus the elasticity of the deformable tube cannot damp the pressure wave created by the lowering of the piston, and the pressure can build-up rapidly from the start of piston movement, which has the effect of enduring a sharply defined start to ejection of the liquid. Nevertheless the diaphragm pump described in the United States Patent No. 3,127,845 does not constitute an acceptable solution as an atomiser pump.

In fact an atomiser for cosmetic products must be subject to two constraints: on the one hand it must not leak in an up-side-down position, and on the other hand it must be easily operated. It is necessary that the dip tube connecting the manual diaphragm pump with the interior space of the associated bottle should be filled with liquid for the pump to be in an operational state, i.e. primed. Thus the air contained therein at the instant of the first use of the atomiser should be discharged after a few pump strokes. Moreover the atomiser is capable of becoming unprimed in the course of use, for instance if a dispensing operation is started while the bottle is in an up-side-down position which has the result of emptying the dip tube of the liquid contained in it and filling it with air enclosed in the atomiser bottle.

It is an object of the present invention to provide a new diaphragm pump allowing both easy priming and ejection of the liquid, thanks to which a dispensing jet may be formed with the characteristics required for the dispensing of cosmetic products in spray form.

Accordingly the present invention provides a manual diaphragm pump for dispensing a liquid product in a container, said pump being connected to a dip tube and being adapted to be fixed on a neck of such a container so that the dip tube can extend into the interior space of the said container, said pump comprising: a compression chamber having at least a part of its wall constituted by an elastically deformable diaphragm; an inlet valve upstream of said compression chamber and an outlet valve downstream of the compression chamber; and means for deforming the diaphragm in an alternating manner; wherein the diaphragm deforming means include a member which bears on the diaphragm and has a shape conforming to that of the engaged part of the diaphragm; and wherein over substantially the whole of the rest of the diaphragm a rigid supporting surface supports the diaphragm, and wherein if VO designates the internal volume of the compression chamber comprised between the inlet and outlet valves before the pumping deformation of the diaphragm and V denotes the reduction of the volume of the compression chamber under maximum pumping deformation of the diaphragm by the operating means then V Viz 0.23 o Preferably the V/VO ratio, which must be as high as possible is greater than 0.6.

The manual diaphragm pump described in British Patent No. 647,604 has a V/VO ratio which is far below the limiting value of 0.23 indicated above. Similarly, in spite of the sharply defined liquid ejection which it allows, the diaphragm pump of United States Patent No. 3,127,845, which as has been seen is a pump for corrosive or volatile liquids at high pressure, is not capable of being used as an atomiser pump by reason of the value of the V/VO ratio which accordng to the drawing of said United States Patent No. 3,127,0845 must clearly be lower than 0.23.

In a preferred embodiment the outlet valve is set so that it opens only from a predetermined pressure obtaining within the compression chamber in order to contribute to a sharply defined ejection of the liquid and at the same time to prevent any leakage of the liquid when the atomiser is in an up-side-down position; the internal excess pressure differential as from which the outlet valve opens is approximately 0.3 kg/cm2; the operating member is a piston engaging the said tubing; thevdiaphragm is an elastic tubing bounding the compression chamber of the pump and fitted in a bore of the pump barrel; the outer and inner cross sections of the deformable tubing and the inner cross section of the bore enclosing the deformable tubing have circular cross sections; the operating piston is displaced along an axis substantially perpendicular to the axis of the tubular diaphragm in the compression chamber; the bore in which the elastic tubing is fitted, and the bore in which the pump piston is displaced, are defined in a single component forming the pump body; the inlet and outlet valves are sub-assemblies attached to the pump body at the ends of the bore which encloses the deformable hose, the said sub-assemblies serving to close the ends of the said hose.

It is clear that there will not be any sealing or jamming problem in the region of the operating piston because the piston is separated from the compression chamber by the deformable wall of the elastic tubing. Moreover, since, in its zone which is contiguous with the piston, the wall of the deformable tubing is supported by the piston end which conforms to the external shape of the tubing and since in all its remaining wall areas the elastic tubing bears on the wall of the pump body, the tubular diaphragm does not damp the pressure wave created by the depression of the operating piston. Thus a sharply defined ejection of the liquid may be obtained, while with the usual diaphragm pumps, such as that described in the above-mentioned British Patent No. 647.604 the ejected dose is subject to a very gradual build-up. and then a similar decay. This ejection is further sharpened in definition thanks to the use of an outlet valve which only opens after a desired precompression of the liquid within the chamber. The liquid ejected by the pump may then feed a spray nozzle and form a spray jet having the characteristics desirable for dispensing cosmetic products. It will be seen that the manual diaphragm pump according to the present invention is an extremely economic embodiment and that its operation is totally reliable taking into account its facility of starting.

In order that the present invention may more readily be understood, one embodiment thereof will now be described merely by way of a purely illustrative and non-restrictive example, reference being made to the accompanying drawing in which the sole Figure represents an axial cross section of a pump according to the invention.

Referring to the drawing there will be seen a container, in this case a bottle 1, containing a cosmetic product to be dispensed comprising a threaded neck 2 supporting the carrier or base 3 of a pump according to the invention. An O-ring seal 4 is interposed between the end of neck 2 and the bottom of the threaded bore hole of base 3 and maintained in compressed state.

The threaded bore of carrier 3, which co-operates with the neck, is extended by a smaller diameter threaded bore coaxial therewith and within which there is threadedly engaged a sub-assembly constituting the inlet valve 5 of the pump. This valve 5 is a simple ball valve which communicates at its downstream end, with a channel 6 cut out into carrier 3 of the pump at the bottom of the bore hole accommodating valve 5. The zone of carrier 3 where channel 6 is cut out has an external shape in the form of an upper cylindro-conical protuberance 7 whose cylindrical lower portion serves to fix the pump body 8 onto carrier 3 by bonding or, as in this case, screwing. At the lower part of valve 5 is a dip tube 9 which extends as far as the bottom of bottle 1.

The pump body 8 is a substantially cylindrical component in which there has been arranged a bore of circular cross section whose two ends are conically widened and end in cylindrical bores having a greater diameter than that of the central bore portion. In the central bore portion a length 10 of rubber tubing has been arranged with an external diameter equal to the inner diameter of the central bore portion of the pump body. One of the ends of the bore of the pump body 8 is positioned on the cylindro-conical protuberance 7 of carrier 3, and the corresponding end of tubing 10 is then held between the protuberance 7 and the wall of the pump body. The other end of the bore of the pump body receives a sub-assembly 11, constituting the outlet valve of the pump, this sub-assembly having been screwed into the cylindrical end bore hole of the pump body and comprising a conical part which co-operates with the corresponding conical mouth of the bore of the pump body. In this way the corresponding end of tubing 10 is held between valve 11 and the wall of pump body 8. The outlet valve 11 is a valve which comprises there within a calibrated spring (not shown in the drawing). An end fitting 12, screw fitted onto outlet valve 11, carries a spray nozzle of the conventional type. Perpendicularly to the axis of the bore enclosing tubing 10 there has been cut out in the pump body 8 a bore 13 which traverses the whole lateral surface of the pump body and within which is a piston 14 having the external shape of the resilient wall of tubing 10. Piston 14 is extended towards the outside of the pump body 8 by a rod 15 ending in an operating button 16. The piston 14 is maintained in its bore hole 13 by means of a stop ring 17 which is bonded to the external wall of the pump body 8. A helical compression spring 18, arranged around rod 15 between the pump body 8 and the push button 16, urges the piston 14 away from the tubing 10 and into abutment with the stop ring 17.

The manual ejection pump which has been described above is designed so as to satisfy two conditions: (a) that of not letting the liquid escape when the atomiser is turned up-side-down, i.e. when the end fitting 12 points downwards; and (b) that of easy starting.

In fact it may be that the dip tube 9 should be in a condition in which it is not entirely filled with liquid, but instead contains air so that the manual pump is not in a primed condition. To achieve this it is necessary to prime the manual pump, either during the first use of the atomiser, or following an accidental loss of priming due for example to actuating the manual pump when the atomiser is turned up-side-down and the dip tube is no longer supplied with the liquid contained in the bottle.

To avoid any leakage when the atomiser is in an up-side-down position, and to contribute also towards a sharply defined ejection of the dose of product contained in the compression chamber, the spring of outlet valve 11 is set so that the outlet valve opens when there is, in the compression chamber, a pressure excess of approximately 0.3 kg/cm2 over atmospheric, (i.e. a pressure of 1.3 kg per cm2).

Assume VO is the volume of the compression chamber, (that is to say the whole internal volume comprised between the admission and outlet valves 5 and 11, when piston 14 is held off by spring 18) and V is the "swept" volume or compression volume (that is to say the reduction of volume VO of the compression chamber when piston 14 is completely home).

In these conditions, for the manual pump to be able to start it is necessary that in the first pumping action the air which is contained in the compression chamber should be compressed to a pressure higher than the opening pressure of the outlet valve (1.3 kg/cm2) so that this volume of air can be ejected by the outlet valve. Thus it is necessary that V Vo - o or alternatively: V V, > 0.23 VO In the embodiment illustrated in the drawing the V/VO ratio is approximately 0.27.

However it is particularly advantageous to have as high a V/VO ratio as possible and preferably one which is higher than 0.60.

When the user of the pump presses on operating push button 16, it drives piston 14 towards the axis of the hose 10, this movement being made possible by the elastic deformation of the wall of tubing 10, which constitutes the resilient diaphragm of the pump.

If it is supposed that the compression chamber formed within tubing 10 between the two valves 5 and 11 is initially filled with liquid, it will be seen that the depressing of the piston 14 produces in the compression chamber a reduction in volume and consequently an increase in pressure. When the pressure within the compression chamber attains the opening pressure of the outlet valve 11, this valve opens to allow the ejection of the liquid product contained in the compressed space. It should be noted that valve 11 will close again at the end of the ejection operation once the pressure in the compressed space falls below the opening pressure of the valve, following the ejection of a quantity of the liquid product.

When the user relaxes his bearing pressure on push button 16 the return spring 18 returns piston 14 in its initial position, that is to say into the position where it does not project into the bore which contains tubing 10. This allows the tubing 10 to dilate, thanks to opening of inlet valve 5 and the elasticity of the tubing itself, and there will thus be an increase in the internal volume of the compression chamber between the two valves 5 and 11, and consequently a reduction in pressure. Upon the opening of valve 5, a quantity of liquid corresponding to that which has been ejected during the preceding operation will be induced into the compression chamber via dip tube 9.

It will thus be seen that the pump according to the invention allows the ejection, on the basis of a determined precompression level, of a predetermined volume of the liquid product each time the user presses on push button 16.

It is clear that the preferred embodiment of such a pump is extremely economical and that its functioning is reliable for a very considerable number of ejections. Moreover, although it is a diaphragm pump, the pump allows a sharply defined ejection by reason of the fact that all the wall zones of tubing 10 are supported either by the wall of the pump body 8, or by the end of piston 14 which takes the external shape of hose 10. Thus, the resilient tubing wall at parts away from the area of engagement by the piston 14 cannot expand to damp the pressure wave created by the depression of the piston 14, and this helps to ensure a sudden build-up and then a rapid decay of pressure within the compression chamber and hence a sharply defined start and finish to the ejection, without spluttering, of the dose of the liquid product. With a spray nozzle, such a manual pump allows spray jets to be obtained such as those which are required for the dispensing of cosmetic products.

Moreover the piston 14 being separated from the product to be dispensed, cannot be subject to any risk of jamming of the piston by the drying of the product in the mechanism.

WHAT WE CLAIM IS: 1. A manual diaphragm pump for dispensing a liquid product in a container, said pump being connected to a dip tube and being adapted to be fixed on a neck of such a container so that the dip tube can extend into the interior space of the said container, said pump comprising: a compression chamber having at least a part of its wall constituted by an elastically deformable diaphragm; an inlet valve upstream of said compression chamber and an outlet valve downstream of the compression chamber; and means for deforming the diaphragm in an alternating manner; wherein the diaphragm deforming means include a member which bears on the diaphragm and has a shape conforming to that of the engaged part of the diaphragm; and wherein over substantially the whole of the rest of the diaphragm a rigid supporting surface supports the diaphragm, and wherein if VO designates the internal volume of the compression chamber comprised between the inlet and outlet valves before the pumping deformation of the diaphragm and V denotes the reduction of the volume of the compression chamber under maximum pumping deformation of the diaphragm by the operating means then

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. so that this volume of air can be ejected by the outlet valve. Thus it is necessary that V Vo - o or alternatively: V V, > 0.23 VO In the embodiment illustrated in the drawing the V/VO ratio is approximately 0.27. However it is particularly advantageous to have as high a V/VO ratio as possible and preferably one which is higher than 0.60. When the user of the pump presses on operating push button 16, it drives piston 14 towards the axis of the hose 10, this movement being made possible by the elastic deformation of the wall of tubing 10, which constitutes the resilient diaphragm of the pump. If it is supposed that the compression chamber formed within tubing 10 between the two valves 5 and 11 is initially filled with liquid, it will be seen that the depressing of the piston 14 produces in the compression chamber a reduction in volume and consequently an increase in pressure. When the pressure within the compression chamber attains the opening pressure of the outlet valve 11, this valve opens to allow the ejection of the liquid product contained in the compressed space. It should be noted that valve 11 will close again at the end of the ejection operation once the pressure in the compressed space falls below the opening pressure of the valve, following the ejection of a quantity of the liquid product. When the user relaxes his bearing pressure on push button 16 the return spring 18 returns piston 14 in its initial position, that is to say into the position where it does not project into the bore which contains tubing 10. This allows the tubing 10 to dilate, thanks to opening of inlet valve 5 and the elasticity of the tubing itself, and there will thus be an increase in the internal volume of the compression chamber between the two valves 5 and 11, and consequently a reduction in pressure. Upon the opening of valve 5, a quantity of liquid corresponding to that which has been ejected during the preceding operation will be induced into the compression chamber via dip tube 9. It will thus be seen that the pump according to the invention allows the ejection, on the basis of a determined precompression level, of a predetermined volume of the liquid product each time the user presses on push button 16. It is clear that the preferred embodiment of such a pump is extremely economical and that its functioning is reliable for a very considerable number of ejections. Moreover, although it is a diaphragm pump, the pump allows a sharply defined ejection by reason of the fact that all the wall zones of tubing 10 are supported either by the wall of the pump body 8, or by the end of piston 14 which takes the external shape of hose 10. Thus, the resilient tubing wall at parts away from the area of engagement by the piston 14 cannot expand to damp the pressure wave created by the depression of the piston 14, and this helps to ensure a sudden build-up and then a rapid decay of pressure within the compression chamber and hence a sharply defined start and finish to the ejection, without spluttering, of the dose of the liquid product. With a spray nozzle, such a manual pump allows spray jets to be obtained such as those which are required for the dispensing of cosmetic products. Moreover the piston 14 being separated from the product to be dispensed, cannot be subject to any risk of jamming of the piston by the drying of the product in the mechanism. WHAT WE CLAIM IS:

1. A manual diaphragm pump for dispensing a liquid product in a container, said pump being connected to a dip tube and being adapted to be fixed on a neck of such a container so that the dip tube can extend into the interior space of the said container, said pump comprising: a compression chamber having at least a part of its wall constituted by an elastically deformable diaphragm; an inlet valve upstream of said compression chamber and an outlet valve downstream of the compression chamber; and means for deforming the diaphragm in an alternating manner; wherein the diaphragm deforming means include a member which bears on the diaphragm and has a shape conforming to that of the engaged part of the diaphragm; and wherein over substantially the whole of the rest of the diaphragm a rigid supporting surface supports the diaphragm, and wherein if VO designates the internal volume of the compression chamber comprised between the inlet and outlet valves before the pumping deformation of the diaphragm and V denotes the reduction of the volume of the compression chamber under maximum pumping deformation of the diaphragm by the operating means then

V > 0.23 VO

2. A pump according to claim 1, wherein the value of the V/VO ratio is greater than 0.60.

3. A pump according to claim 1 or 2, wherein said outlet valve is set so as to open only once a predetermined excess pressure differential obtains within said compression chamber.

4. A pump according to claim 3, wherein said excess pressure differential is approximately 0.3kg/cm.

5. A pump according to any one of the preceding claims 1 to 4, wherein said diaphragm is an elastically deformable tubing fitted into a bore of the pump body.

6. A pump according to claim 5, wherein the diaphragm deforming member is a piston engaging the said tubing.

7. A pump according to claim 6, wherein the external and internal cross sections of the elastically deformable tubing and the internal cross section of the bore which encloses the deformable tubing are circular in cross section.

8. A pump according to claim 6 or 7, wherein the piston is displaceable along an axis which is substantially perpendicular to the axis of the tubular diaphragm in the compression chamber.

9. A pump according to claim 6, 7 or 8, wherein the bore in which the elastically deformable tubing is fitted and the bore in which the piston of the pump is displaceable are formed in a single component forming the body of the pump.

10. A pump according to any one of claims 6 to 9, wherein the inlet and outlet valves are sub-assemblies attached to the body of the pump at the ends of the bore enclosing the elastically deformable tubing, the said sub-assemblies serving to close the ends of the said hose.

11. A manual diaphragm pump for dispensing a liquid product in a container such pump being constructed substantially as hereinbefore described with reference to the accompanying drawing.

12. An atomiser for liquid products, this atomiser comprising a container which contains the liquid product to be atomised and a manual diaphragm pump fixed to the neck of the container, the said pump communicating via a dip tube with the internal volume of the associated container, wherein the manual diaphragm pump is a pump according to one of the claims 1 to 11.