EP1911526A1 - Corrosion-resistant foam pump - Google Patents

Abstract

The pump has a compression unit compressing a bell to reduce an internal space (171) and increase external space (170) of the bell. The bell is returned to a non compressed position to decrease the external space and increase the internal space. The space (170) is pressurized to produce air flow. The increase of the space (171) causes a depression in the space (171), in which liquid (14) is aspirated to produce a stirred mixture by a liquid flow and the air flow. A check valve (19b) associated to an outlet pipe (100) either allows an additional air flow to the space (171) or closes the pipe.

Description

The invention relates to the field of devices for producing foam by hand pumps operating on the basis of foaming liquid. It relates more particularly to foam pumps for the use of corrosive products, such as ammonia, incorporated in the foaming liquid.

The patent EP 1 190 775 discloses a dispenser comprising a liquid pump combined with an air pump for mixing the two fluids in an outlet passage to a foam discharge opening. The air pump comprises in particular an air chamber in which is disposed an activation spring of the two pumps, the metal spring disposed in the air being thus protected from any contact with the foaming liquid to prevent corrosion of the spring by a liquid containing corrosive substances. However, the spring is likely to be damaged by vapors, for example ammonia, emanating from the foaming liquid. In addition, the dual pump system requires complex assembly of parts to provide the air chamber, the outlet passage and the liquid chamber, as well as communication passages with the chambers or with the outlet passage.

The present invention therefore aims to overcome one or more of the disadvantages of the prior art by providing a foam pump comprising a simple mounting pumping and mixing a foaming liquid in the air, this assembly being not deteriorated in the case of use with a corrosive liquid, such as ammonia.

• une cloche déformable en matériau élastique résistante à la corrosion qui cloisonne la chambre en d'une part un espace extérieur à la cloche communiquant avec l'entrée d'air et d'autre part un espace intérieur de la cloche communiquant avec le conduit de sortie et l'entrée de liquide,
• des moyens d'étanchéité rendant le cloisonnement hermétique à l'exception d'un ou plusieurs passages d'air de dimensions déterminées traversant la cloche,
• un régulateur de débit disposé dans le conduit de sortie,
• des moyens de compression de la cloche actionnés par un utilisateur pour réduire l'espace intérieur et augmenter l'espace extérieur et pour ouvrir l'entrée d'air à clapet et produire un flux négligeable d'air, passant par les passages d'air dimensionnés, par rapport à un flux principal d'un mélange brassé expulsé par le conduit de sortie, via le régulateur de débit ouvert, pour être transformé en mousse par au moins une grille de filtrage disposée dans le conduit de sortie,

le retour de la cloche, par élasticité, dans une position non compressée, réalisant une diminution de l'espace extérieur impliquant, par fermeture du clapet membrane, une pressurisation de l'espace extérieur produisant un flux d'air perturbateur entrant dans l'espace intérieur par les passages d'air dimensionnés, le retour de la cloche réalisant une augmentation de l'espace intérieur impliquant une dépression dans l'espace intérieur dans lequel est aspiré le liquide du réservoir pour produire un mélange brassé par au moins un flux de liquide et le flux d'air perturbateur, le régulateur associé au conduit de sortie soit laissant un flux d'air supplémentaire entrer dans l'espace intérieur soit fermant le conduit de sortie.This objective is achieved by a foam pump comprising a chamber into which an outlet duct opens, the outlet duct leading to the outside of the pump through an expulsion orifice of the foam, a means of supplying the chamber with foaming liquid by a liquid inlet associated with a non-return device and communicating with a foaming liquid tank, at least one air inlet with a valve membrane disposed at the periphery of the chamber and communicating with the outside of the pump, characterized in that it comprises:

• a deformable bell made of corrosion-resistant elastic material which partitions the chamber on the one hand a space outside the bell communicating with the air inlet and on the other hand an interior space of the bell communicating with the outlet duct and the liquid inlet,
• sealing means making the partitioning hermetic except for one or more air passages of determined dimensions passing through the bell,
• a flow regulator disposed in the outlet duct,
• user-operated bell compression means for reducing the interior space and increasing the external space and for opening the valve air inlet and producing a negligible flow of air through the air passages dimensioned, with respect to a main flow of a stirred mixture expelled by the outlet duct, via the open flow regulator, to be transformed into foam by at least one filtering grid disposed in the outlet duct,

the return of the bell, by elasticity, in an uncompressed position, realizing a decrease in the external space implying, by closing the diaphragm valve, a pressurization of the external space producing a disturbing flow of air entering the space interior by the sized air passages, the return of the bell effecting an increase in the interior space involving a depression in the interior space in which the liquid is drawn from the tank to produce a mixture stirred by at least one flow of liquid and the disturbing air flow, the regulator associated with the outlet duct is allowing an additional air flow to enter the interior space or closing the outlet duct.

According to another particularity, the regulator is produced by a narrowing of the outlet duct according to a determined section, the section of the outlet duct and the dimensions of the air ducts being determined. in order to control the additional flow and the disturbing air flow to maintain the depression in the interior space.

According to another particularity, the regulator is a non-return valve allowing the main flow coming from the interior space to pass towards the outlet duct and being closed in the opposite direction, the dimensions of the air passages being determined so as to control the disturbing air flow to keep the depression in the interior space.

In another feature, the sealing means comprises a lip formed at the periphery of larger diameter of the bell to press against a wall of the chamber around the liquid inlet.

According to another feature, the bell comprises a rigid peripheral ring connected to the lip and resting against the side walls of the chamber.

According to another feature, the bell comprises a deformable portion bulging outwardly of the bell and having the air passage or passages.

According to another particularity, the compression means of the bell comprise a sliding tube mechanically and sealingly connected to a sleeve extending the weakest section of the bell, the tube penetrating into the chamber in a sealed manner, the tube communicating with a pressure head for producing the outlet duct, the sealing means comprising a fitting of the sliding tube with a tubular portion of the bell less elastic than the deformable part and opening on the inside, the deformable part extending on the other hand; by the rigid ring.

According to another feature, the air passage or passages are made by one or more holes of cross sections determined.

According to another feature, the air passage or passages are made by one or more slits of determined lengths.

According to another feature, the air passage or passages are made by one or more bulges projecting towards the inside of the bell and pierced at their apex.

• la figure 1 représente une vue en coupe d'un exemple de pompe selon l'invention,
• la figure 2 représente une vue en coupe du corps de pompe de la figure 1 en phase d'expulsion,
• la figure 3 représente une vue en coupe du corps de pompe de la figure 1 en phase d'aspiration,
• la figure 4 représente une vue en coupe d'un corps de pompe en phase d'aspiration, selon un autre exemple de réalisation ;

Other features and advantages of the present invention will appear more clearly on reading the description below, made with reference to the accompanying drawings, in which:

• FIG. 1 represents a sectional view of an exemplary pump according to the invention,
• FIG. 2 represents a sectional view of the pump body of FIG. 1 in the expulsion phase,
• FIG. 3 represents a sectional view of the pump body of FIG. 1 during the suction phase,
• FIG. 4 represents a sectional view of a pump body in the suction phase, according to another exemplary embodiment;

The invention will now be described with reference to the figures mentioned above. The pump, shown in Figure 1, produces foam when the user presses on a head (11) of the pump. Without limitation, the pump is portable by hand. The foam is expelled by an expulsion orifice (10) of the expulsion head (11) which forms part of an outlet duct (100) associated with filtering grids (12). A reservoir (13) containing foaming liquid (14) is attached to a pump body (15), for example by screwing or clipping. The foaming liquid (14) comprises, for example, an active agent, a foaming agent and water and needs to be mixed with air to produce foam. The active agent or the foaming agent include, without limitation, a corrosive product, such as ammonia. A plunger tube (16) includes an inlet (16a) disposed, for example, in the bottom of the reservoir (13), and is recessed at its outlet (16b) on a pump inlet (15a). The liquid (14) is thus pumped into the reservoir (13) by the pump while circulating in the plunger tube (16). The reservoir (13) is associated, in a non-limiting manner, with a non-return valve disposed in the wall of the reservoir or other known means to fill the air gap inside the tank (13), resulting from the pumping of liquid (14).

A bell (20, 22, 23, 24) made of an elastic material, including for example plastic or rubber, is inserted into a chamber (170, 171) disposed in the pump body (15). The bell is thus resistant to corrosive products such as ammonia. The chamber (170, 171) is formed by a lower wall pierced with an inlet (17a) of liquid. The chamber is formed on the other hand by side walls formed by the pump body (15) and is limited by an upper wall formed by a cover (18) fixed to the pump body (15), for example by screwing or by clipping. The lid (18) has one or more air inlets (30) in communication with the chamber (170, 171). On the other hand, the cover (18) is associated with a sliding expulsion tube (180) providing an expulsion outlet (17b) in communication with the chamber (170, 171). The sliding connection between the cover (18) and the sliding tube (180) is sealed. The sliding tube communicates on the other hand with the expulsion head, and comprises for example one or more grids (12) for filtering. The expulsion outlet thus provides an end of the outlet duct (100) formed in part by the sliding tube (180). The tube (108) sliding fits for example in the head (11) of expulsion.

The pumping inlet (15a) is for example associated with a non-return device (19a) in order to prevent a circulation of fluid passing from the liquid inlet (17a) of the chamber to the inlet (15a) of pumping. This device (19a) anti-return comprises for example a plastic ball or glass, resting on a frustoconical seat and held in a housing defined by the seat and holding lugs. In a nonlimiting manner, the holding lugs are deformable to allow a force insertion of the ball in its housing. The ball is preferably made of plastic, as is the entire pump, so as to be recyclable.

The air inlets (30) formed in the cover (18) are associated with a non-return device preventing air from leaving the chamber (170, 171). This non-return device is for example made by a membrane (31) flexible disposed opposite the air inlets (30) and held close to the air inlets (30) by carrier arms (18a) belonging to the cover (18). The membrane is for example in the form of a ring, made of a flexible material and kept close to the holes (30) of air formed in the cover (18) in a circle.

The expulsion outlet (17b) belonging to the sliding tube (180) is associated, for example, with a non-return valve (19b), made for example in the form of a plastic ball resting on a frustoconical seat and associated with holding pins. This non-return valve (19b) prevents a flow of fluid entering the chamber (170, 171).

According to an alternative embodiment, the non-return valve, disposed at the outlet (17b) expulsion, is formed by a needle resting on a frustoconical seat forming the edges of the outlet (17b) of expulsion. A flow exiting the chamber (170, 171), by the exit (17b) expulsion, pushes the needle, for example against lugs limiting the movement of the needle. The needle resting on its frustoconical seat blocks the expulsion outlet preventing a flow of fluid entering the chamber (170, 171).

The bell (20, 22, 23, 24) separates the chamber (170, 171) into two parts: an upper part (170) containing air and a lower part (171) in which the air and the liquid ( 14) are brewed to form a foaming mixture. The upper portion (170) and the lower portion (171) of the chamber are sealed apart with the exception of one or more air holes (21) formed in the bell. Sealing is performed at the bottom wall of the chamber (170, 171) by a deformable lip (22) belonging to the bell, resting against the bottom wall and arranged around the inlet (17a) of liquid the chamber (170, 171). Sealing is performed on the other hand at the outlet (17b) expulsion by a rigid appendix (23), belonging to the bell, in a non-limiting manner, embedded in a portion (181) offset from the tube (180). ) sliding or recessed around the tube (180) sliding. The appendix (23) has a mixing expulsion passage (23a) foaming communicating with the conduit (100) outlet in the tube (180) sliding.

The appendage (23) extends widening, at its lower part, by a portion (24) curved flexible and deformable, belonging to the bell, in which are formed the holes (21) of passage of the air. The portion (24) curved flexible and deformable extends down to a ring (20) of the rigid bell, bearing against the side walls of the chamber (170, 171). The rigid ring (20) is extended downwards by the deformable lip (22). In a nonlimiting manner, the rigid ring is circular and bears against a cylindrical wall of the chamber.

According to another embodiment, without limitation, the side walls of the chamber against which the rigid ring is supported, have protruding edges or have a hexagonal or octagonal section.

By its deformation, the domed portion (24) reduces the interior volume of the bell. In addition, the curved portion (24) has elastic properties and naturally tends towards a raised position, as shown in FIG. 1, in which the interior volume of the bell is maximum, the internal volume of the bell corresponding to the portion (171) ) lower chamber. The upper part (170) of the chamber which corresponds to the outside of the bell is in communication on the one hand with the outside of the pump via the air inlet (s) (30) produced in the cover (18). ) and on the other hand with the interior (171) of the bell, via the holes (21) for the passage of air.

dans laquelle µ est la viscosité du fluide, L est la longueur du conduit et R est le rayon de la section circulaire. Dans le cas de la cloche la longueur du conduit est par exemple prise égale à l'épaisseur de la cloche au niveau de la partie bombée. Le rayon sera déterminé en fonction de la section moyenne du trou (21) et la viscosité est par exemple celle du mélange moussant.The holes (21) made in the bell connecting the upper portion (170) of the chamber to its lower portion (171), have a surface section determined to have a determined flow resistance. For example, in the case of a Poiseuille flow, in a duct of circular section and of determined length, for a flow in a laminar flow, the flow resistance is given by the relation: $${\mathrm{R}}_{\mathrm{h}}\mathrm{=}\left(\mathrm{8.}\mathrm{\mu }\mathrm{.}\mathrm{The}\right)\mathrm{/}\left(\mathrm{\pi }\mathrm{.}{\mathrm{R}}^{\mathrm{4}}\right)$$

where μ is the viscosity of the fluid, L is the length of the conduit and R is the radius of the circular section. In the case of the bell, the length of the duct is for example equal to the thickness of the bell at the curved portion. The radius will be determined according to the average section of the hole (21) and the viscosity is for example that of the foaming mixture.

dans laquelle δP est la différence de pression entre l'entrée et la sortie du conduit et Q est le débit volumique de fluide.The flow resistance is for example used to estimate the flow rate according to the relation: $${\mathrm{R}}_{\mathrm{h}}\mathrm{=}\mathrm{dP}\mathrm{/}\mathrm{Q}\mathrm{,}$$

where ΔP is the pressure difference between the inlet and outlet of the duct and Q is the volume flow rate of the fluid.

The expulsion is activated by the support of a user on the head (11) of the pump which causes the descent of the tube (180) sliding disposed under the head (11). This tube (180) slides in the cover (18) of the pump sealingly and descends inside the chamber (170, 171). The downward movement (M1) of the sliding tube (180) is in particular represented in FIG. 2 by two double arrows directed downwards. The descent of the tube (180) sliding, bearing against the appendage (23) rigid of the bell, causes deformation of the portion (24) curved flexible and elastic bell. This deformation of the bell reduces the internal space (171) of the bell that flattens towards the lower wall of the chamber. The reduction of the space (171) inside the bell causes, on the one hand, an increase in the pressure inside (171) of the bell and on the other hand, a decrease or a vacuum on the outside ( 170) of the bell. The non-return valve (19a) disposed before the arrival (17a) of liquid closes while the check valve (19b) disposed after the expulsion outlet (17b) opens to expel, according to a first flow (F1), a fluid, such as for example a foaming mixture, from the inside (171) of the bell to the outlet duct (100) equipped with grids (12) to produce foam available at the orifice (10) output of the pump. A vacuum being created in the upper part (170) of the chamber, the valve (18a, 31) non-return associated with the air inlets (30) formed in the cover (18), is placed in an open position and allows air to pass from the outside of the pump into the upper part (170) of the chamber, according to a second flow (F2).

The section or holes (21) for passage between the outside (170) and the inside (171) of the bell, is made small enough for the flow resistance of all of these holes (21). is sufficiently large in front of the flow resistance of the expulsion conduit (100). Thus the fluid inside (171) of the bell flows mainly through the expulsion conduit (100) connecting the expulsion outlet (17b) to the expulsion orifice (10), the flow (F3 ) fluid escaping from the inside (171) to the outside (170) of the bell, during the compression phase, being negligible. The flow resistance of the expulsion duct (100) is also dependent on the obstacles disposed in the duct which are the non-return valve (19b) and the filtering grids (12).

According to another exemplary embodiment, the holes are replaced by slots of determined size to have a determined flow resistance.

According to another embodiment, the holes are replaced by round projections protruding inward (171) of the bell and pierced at their top, allowing air to pass from the outside (170) inwards (171). ) of the bell. On the other hand, these bosses block, by their deformation, the passage of air from the inside (171) to the outside (170) of the bell.

When the user releases the expulsion head (11), the pressure previously exerted on the bell by means of the sliding tube (180) is eliminated, and the bell tends towards the maximum high position, according to a movement (M2) amount, as shown in Figure 3. The representation of Figure 3 shows the bell (20, 22, 23, 24) in a movement (M2) rising, in a position close to its maximum high position of Figure 1. The the volume of the upper part (170) of the chamber decreases, thereby creating an overpressure in the upper part (170) which causes the closing of the nonreturn valves (31, 18a). associated with the air inlets (30) made in the cover (18). On the other hand, the increase in the volume of the lower part (171) of the chamber creates a depression in this lower part (171) associated with a suction phenomenon towards the lower part (171). This aspiration causes on the one hand the opening of the valve (19a) disposed upstream of the inlet (17a) of liquid (14) allowing a suction of liquid (14) in the portion (171) of the lower chamber. A flow (F5) of liquid thus enters the interior (171) of the bell. On the other hand the depression is associated with a closure of the device (19b) non-return associated with the conduit (100) output. The valve (19b) is placed for example in its closed position. The communication holes (21) between the upper portion (170) of the chamber and the lower portion (171) of the chamber are dimensioned such that the resistance of air flow through all the holes (21) is close to the flow resistance of the foaming liquid rising from the tank through the dip tube via the valve, to the entry of foaming liquid. Thus liquid is sucked into the lower portion (171) of the chamber together with air from the upper portion (170) of the chamber.

The passage holes (21) between the upper portion (170) and the lower portion (171) of the chamber have a section small enough to provide airflow resistance and maintain a minimum depression determined at inside (171) of the bell, to create a suction of liquid. The determined minimum depression is such that the liquid is sucked against frictional forces due to flow and against gravity forces. In addition the air passing through the holes (21) in the bell with a determined speed, creates an aerodynamic disturbance in the portion (171) inside the bell. The non-return devices (31, 18a) associated with the air inlets (30) being closed, the rising movement of the deformable curved portion (24) of the bell creates an overpressure in the upper part (170) of the chamber, at the same time as a depression in the lower part. The pressure difference between the ends of the holes (21) passage is important and creates a flow (F4) of disruptive air. The aerodynamic perturbation (F4) associated with a jet (F5) of liquid starting from the inlet (17a) of liquid and directed inward (171) of the bell, causes a mixing of the liquid (14) foaming with the air producing a foaming mixture in the lower part (171) of the bedroom.

This foaming mixture is then expelled when the user presses on the pump head (11) and then passes through one or more filter grids (12) to produce foam as previously described.

According to another embodiment, as represented in FIG. 4, the outlet duct (100) is not associated with a non-return device, but the bell has a determined section at the outlet (17b) of expulsion of its part (23) rigid. The rigid part (23) of the bell, for example tubular, is thus narrowed in its upper part, at the level of the outlet (17b) of expulsion. This shape of the rigid portion (23) of the bell thus allows the outgoing flow (F1) to pass from the inside (171) of the bell to the outlet duct (100) while limiting an opposite flow. In a nonlimiting manner, a determined disturbing flow (F6) is produced, by a residual opening, at the expulsion outlet (17b), to have a flow rate similar to the flow rate of the air flows (F4) by the holes (21) passing through the bell. That is to say that the flow (F6) of air entering the chamber (171) below the outlet (17a) expulsion is such that the depression inside (171) of the bell is kept to allow suction of the liquid (14) through the inlet (17a) of liquid.

It should be obvious to those skilled in the art that the present invention allows embodiments in many other specific forms without departing from the scope of the invention as claimed. Therefore, the present embodiments should be considered by way of illustration, but may be modified within the scope defined by the scope of the appended claims, and the invention should not be limited to the details given above.

Claims (10)

A foam pump comprising a chamber (170, 171) into which an outlet duct (100) opens, the outlet duct (100) opening out of the pump through an orifice (10) for expelling the foam, means for supplying the chamber (170, 171) with foaming liquid (14) via a liquid inlet (17a) associated with a non-return device (19a) and communicating with a foaming liquid reservoir (14), at least an inlet (30) of air with a valve (31, 18a) disposed on the periphery of the chamber (170, 171) and communicating with the outside of the pump, characterized in that it comprises: - a bell (20, 22, 23, 24) deformable corrosion resistant elastic material which partitions the chamber (170, 171) on the one hand a space (170) outside the bell communicating with the inlet (30). ) air and on the other hand a space (171) inside the bell communicating with the conduit (100) outlet and the inlet (17a) of liquid, sealing means (22, 23) making the partitioning hermetic except for one or more air passages (21) of determined dimensions passing through the bell, a flow regulator disposed in the outlet duct (100), user-actuated bell compression means for reducing the internal space (171) and increasing the external space (170) and for opening the air valve inlet and producing a negligible flow (F3) of air, passing through the sized air passages (21), with respect to a main flow (F1) of a stirred mixture expelled through the outlet duct (100), via the open flow regulator, to be transformed into foam by at least one filtering grid (12) arranged in the outlet duct (100), the return of the bell, by elasticity, in an uncompressed position, realizing a decrease in the external space (170) implying, by closing the valve (31, 18a) membrane, a pressurization of the outer space (170) producing a flow (F4) of disruptive air entering the space (171) inside by the air passages (21) dimensioned, the return of the bell making an increase of the space (171) interior involving a depression in the space (171) inside which is sucked the liquid (14) of the reservoir to produce a mixture stirred by at least one flow (F5) of liquid (14) and the flow (F4) of disruptive air, the regulator associated with the outlet duct (100) is leaving a flow ( F6) additional air enter the space (171) inside either closing the outlet duct (100). Foam pump according to Claim 1, characterized in that the regulator is produced by a narrowing of the outlet duct (100) in a given section, the section of the outlet duct (100) and the dimensions of the passages (21) of air being determined to control the additional flow (F6) and the flow (F4) of disturbing air to maintain the vacuum in the interior space (171). Foam pump according to claim 1, characterized in that the regulator is a non-return valve (19b) allowing the main flow coming from the internal space (171) to pass towards the outlet duct (100) and being closed in the opposite direction, the dimensions of the passages (21) of air being determined so as to control the flow (F4) of disruptive air to maintain the depression in the space (171) inside. Foam pump according to claim 2 or 3, characterized in that the sealing means (22, 23) comprises a lip (22) formed at the periphery of a larger diameter of the bell for pressing against a wall of the chamber around the inlet (17a) of liquid. Foam pump according to claim 4, characterized in that the bell comprises a peripheral rigid ring (20) connected to the lip (22) and resting against the side walls of the chamber. Foam pump according to claim 5, characterized in that the bell comprises a deformable portion (24) curved outwardly (170) of the bell and having the or (21) air passages. Foam pump according to claim 6, characterized in that the means for compressing the bell comprise a sliding tube (180) mechanically connected and in leaktight manner to a sleeve extending the weakest section of the bell, the tube penetrating into the bell. a sealed chamber, the tube (180) communicating with a pressure head (11) for producing the outlet duct (100), the sealing means comprising a recess of the tube (180) sliding with a tubular portion (23). the bell less elastic than the portion (24) deformable and opening on the inside, the portion (24) deformable further extending by the ring (20) rigid. Foam pump according to one of Claims 1 to 7, characterized in that the air passage or passages (21) are formed by one or more holes of defined cross sections. Foam pump according to one of Claims 1 to 7, characterized in that the air channel (s) (21) are formed by one or more slits of defined lengths. Foam pump according to one of claims 1 to 7, characterized in that the or passages (21) of air are formed by one or more protruding protrusions inward (171) of the bell and pierced at their apex.

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