MXPA98005341A - Distributor for a liquid or pastoso product that includes means of pumping improvement - Google Patents

Abstract

The present invention relates to a dispensing head of a product of liquid or pasty consistency contained in a reservoir comprising a push button that moves axially, said push button having a body whose internal walls define a volume pumping chamber (22) variable, which has an inlet for the product, sealed by an inlet flap valve supported by a plunger having at least one sealing rim in contact with which the inner walls move between a high position and a low position, causing the passage of the high position and a high position the aspiration of the product to the pumping chamber through the intake valve and causing the passage from the high position to the low position with the output of the product sucked through a valve of distribution flap that closes an exit orifice of said chamber having been provided with a med elastic tensioning devices to return the push button to the raised position, the intake valve being mounted as well as the piston on a ring-clamp crowning said tank presented with said ring a seat for the intake valve to prevent any return of product towards the tank characterized in that the plunger is formed by an annular part made of a rigid or semi-rigid material, and comprises a central part that forms a single piece with the annular part, and is made in the form of a membrane of an elastically deformable material, in which has been made at least one opening to form the said valve

Description

DISTRIBUTOR FOR A LIQUID OR PASTOSO PRODUCT THAT UDES IMPROVED PUMPING MEDIA FIELD OF THE INVENTION The present invention relates to a dispensing head, such as a dispenser equipped with this dispenser head for a liquid or pasty product, comprising a reservoir for the product to be dispensed, having pump means operable by a push button, to cause the distribution of a dose of the product. The dispenser to which the invention relates is of the variable volume deposit type; said tank being constituted, for example, by a flexible bag or by a rigid cylindrical tank provided with a plunger-follower. This distributor is intended, more particularly, to distribute and apply a cosmetic, dermatological or food product, such as, for example, a lotion, a cream, a shampoo or a liquid make-up, a gel, although it can equally distribute all kinds of product liquid or pasty. Such a dispenser is advantageously presented in a compact form, with a REF: 27835 deposit of small content, from a dozen ml to a few hundred ml.

BACKGROUND OF THE INVENTION It is known, for example, from EP-A-0 733 559, in the name of the applicant, a distributor of the kind described, comprising a retractable tank, connected by a first valve to a chamber of variable volume under the action of a push button. This chamber of variable volume is, in turn, communicated with the outside by a second valve. The pulsator comprises a body that constitutes, with a piston integral with the reservoir, the chamber of variable volume. The piston is provided with a central passage, its free end being covered on the side of the chamber by a piece of elastomeric material that fulfills, at the same time, the function of a sealing rim and a unidirectional valve flap; This clapper is able to open towards the variable volume chamber, in response to a depression inside the chamber. The tests carried out by the applicant have shown that the valve, according to EP-A-0 733 559, presents two drawbacks - the adjustment of a sliding sealing rim made of elastomeric material between two rigid walls is difficult to perform; in particular, when a plunger is made whose diameter is only a few millimeters; - the mobility of the plunger is difficult to ensure, s, according to its chemical composition, certain products have a tendency to swell the elastomeric material that constitutes the plunger, this then suffering an expansion, which causes I to lock it inside the chamber and / or the deformation of the valve. On the other hand, DE-U-94 19268 discloses a distributor comprising a compression chamber of variable volume, in communication with a piston, comprising a central product passage sealed by a unidirectional flap valve. The plunger is inserted inside a feed duct, in communication with a tank that contains the product. The valve is made in the form of an annular elastic membrane, whose central hole is sealed by a prominence of the plunger. The membrane is joined to a cylindrical sleeve threaded into an annular groove from which the upper end of the plunger is provided. The sleeve with the valve is made in one piece made of elastomer.

Such an embodiment has several disadvantages, both from the point of view of manufacturing, and from the point of view of the operation: in fact, when the piston is mounted, it is necessary to ensure a first seal between the piston and the sleeve, while the placement in the correct axial position of the membrane with respect to the cjltada protuberance is ensured. If the exact positioning of the membrane is not present, the pump presents leaks, or I, at least, an irregular flow rate. further, it is necessary to ensure a second tightness between the feeding duct and the plunger. On the other hand, due to the assembly of the plunger inside the feed duct, the cross section of the product is limited, which leads to a loss of loads, which implies a difficult operation of the pump. If this step section is increased, a bulky pump is obtained that can not be associated with a distribution head intended to cover low-content deposits. In total, the two stages are necessary for the assembly of the piston in the pump. In the absence of watertight assembly of the different parts mentioned above, the reliability of the operation of the pump is compromised. Thus, the present invention aims to avoid the drawbacks of the prior art, and ensure smooth and reliable operation in use. The distributor, according to the invention, also has a rapid response to the actuation of the pushbutton, in contrast to the distributors which have a ball valve. The invention relates, in particular, to the use of a plunger with an I-valve valve, whose production and assembly are simple to carry out at an advantageous price, and which, moreover, offers a high degree of precision. . I DESCRIPTION OF THE INVENTION The present invention relates to a head of distribution of a product, of liquid or pasty consistency, contained in a tank, comprising a push button that moves axially; This pushbutton has a body whose internal walls define a variable-volume pump chamber, which has an inlet for the product, sealed by an inlet flap valve supported by a plunger, the plunger having at least one rjsborde tightness in contact with which the internal walls move between a high position and a low position; the passage from the low position to the high position causes the suction of the product in the pumping chamber through the intake valve, and causing the passage of the high position to the low position the exit of the product sucked through a valve of flap type distribution that closes an exit hole of said chamber, elastic tension means being provided ?; to place the push button in the high position, both the inlet valve and the piston being mounted on a ring or a clamp crowning said valve; this ring has a seat for the intake valve in order to prevent any return of the product to the tank. This head is particularly suitable for the distribution of relatively viscous products. In particular, the assembly of the membrane on the seat can be permanently hermetic, which is, in particular, convenient for the distribution of relatively fluid products.

In order to increase the reliability of the operation of this dispensing head, the annular part of the plunger can advantageously have a stop-like portion to ensure exact positioning in accordance with the longitudinal axis of the pump, the central part of the piston on the seat. Advantageously, the elastically deformable membrane is fixed on the end part of the plunger during the manufacture of the latter. For this purpose, the intake valve and the annular part can be made by bi-injection or overmolding of two compatible materials. For the injection of the membrane, preferably an elastomeric material is used, particularly thermoplastic, and, more particularly, a material having a Shore A hardness between 15 and 90.

Generally, the elastically deformable material must be able to create, with the rigid or semi-rigid material, a solid connection in the manufacture of the plunger. Thus, by injecting in a suitable mold, for example, firstly, the rigid or semi-rigid material to form the plunger, and then injecting, above, the elastomeric material I of the membrane, this connection is created, by thermofusion, between both materials. It is also possible to work in the opposite direction. In certain cases, it is also possible to overmold two incompatible materials, provided that fixing profiles are provided. However, fortunately, the elastomeric material is chosen from the group of thermoplastic elastomers, such as the group of propylene / ethylene copolymers; of the poly-blockers; of the polyvinyl I; of terpolymers of ethylene, propylene and a diene (IEPDM); of the styrene-butadiene-sequenced polymers (SBS); of the styrene-ethylene-butadiene polymers sequenced (SEBS-SIS); of thermoplastic polyurethanes; of the polypropylene blends with one of the following elastomers: styrene-ethylene-butadiene polymers sequenced (SEBS-SIS); terpolymers of ethylene, propylene and a diene (EPDM); sequenced styrene-butadiene polymers (SBS). It is also considered possible to use, as a flexible material, silicone elastomers, butyl or nitrilp rubbers, latexes or fluorinated elastomers. It is also possible to realize the membrane of natural or synthetic rubber, such as vulcanizable elastomers, rubbers of nitrile or polybutadienes, etc .; in this case, the membrane can be glued or pressed under pressure II on the plunger or b in, fixed by any other appropriate means.

As regards the embodiment of the piston itself, the rigid to semi-rigid material is advantageously chosen from among polypropylenes, high and low density polyethylenes, polyvinyl chlorides (PVC), polyacetals, ethylene-vinyl acetates and their mixtures. , etc ... Advantageously, the plunger has a shape It has a circular shape, similar to a flat washer. In this configuration, the hollow piston is provided with a central protuberance which acts as a seat, arranged in such a way that it comes into contact with the edges of the orifice of the membrane. This arrangement constitutes a unidirectional valve that allows the admission of the product in the pumping chamber. When there is excessive pressure in this chamber, the membrane and, particularly, the edges of the orifice, remain in sealed support on the seat, while a depression in said chamber causes the edges of the orifice of the membrane to detach from the chamber. your seat, I allowing the aspiration of the product. To confer a constituted by an annular part at the apex of a feeding channel formed by the clamp. Advantageously, this annular part can have an annular ridge, intended to rest on the membrane, in the rest position. Preferably, the slots are arranged, discontinuously, following a circular line. In this configuration, the hollow piston is provided with a widened end edge, which forms a seat, arranged so as to come into contact with the membrane at the level of grooves. As in the first embodiment, this arrangement constitutes the intake valve of the product in the pumping chamber. When there is an overpressure in this chamber, the membrane and, particularly, the edges of the grooves are hermetically packed on the seat, while a depression causes the membrane to separate from its seat, thus allowing the product to be aspirated. To further increase the flexibility of the membrane, its thickness can be variable. Thus, the area of the membrane or nearby areas, which are in contact with the seat, may have a thickness less than the rest of the membrane. According to a preferred embodiment of the dispenser of the invention, the ring comprising the feed channel is centered on the longitudinal axis of the distributor and flows directly into the intake valve of the dispensing head, said feed channel being surrounded by a annular portion forming a cavity around the feeding channel; said cavity is delimited, in the place opposite to the feeding channel, by an outer annular skirt carrying means of engagement on the distributor, for example, an annular groove or rib. Advantageously, the cavity has a transverse wall, between, the feed channel and the outer annular skirt, the elastic traction means being located between a stirrup formed by the push button and said transverse wall. The traction means are constituted, for example, by a helical spring of metal, placed around the pumping chamber and the piston located in said cavity. In a variant embodiment, the spring can be obtained directly by molding rigid or semi-rigid plastic material, at the same time as the lower part of the push button with which it forms a body. According to a first possibility of realization, the tank is constituted by a soft and flexible bag, having an open end integral with ring-clamp and in communication with said feeding channel disposed in the piston. In this case, the open end of the bag is closed by the ring, i comprising the latching means, which cooperate with an end edge of a rigid or semi-rigid outer enclosure surrounding said bag. According to a second embodiment, the reservoir is constituted by a rigid or semi-rigid enclosure, in communication with the feeding channel, the engaging means cooperating with an end edge of said rigid or semi-rigid external enclosure, having arranged a follower plunger at the bottom of the tank. This follower piston is able to advance automatically as the extraction of the product takes place according to the longitudinal e e i of the distributor, in response to the depression in the pump chamber.

According to another interesting aspect of the invention, the push button comprising the dispensing valve is provided with a distribution channel, a first end from which it opens into the pumping chamber, the second end being closed by said distrubution valve. For this purpose, this distribution valve is made of elastomeric material and remains in hermetic elastic support against a seat formed around said second end of the distribution channel, able to open when a product is pushed, and applied against the seat when a depression occurs inside the variable volume chamber I and the distribution channel. In order to make the present invention more clearly known, we will now describe, by way of purely illustrative and by no means limiting examples, two embodiments of distributors according to the invention, represented in the attached drawings. Figure 1 represents a schematic view in axial section of a distributor, according to a first embodiment of the invention. Figure 2 'represents an axial view on the piston conformed to the distributor of figure 1. Figure 3 shows a perspective view of the piston according to the distributor of figure 1. Figure 4 represents a schematic view in axial section of a distributor according to a second embodiment of the invention. Figure 5 shows a perspective view of the piston according to the distributor of figure 4. Figure 6 represents a perspective view of a variant embodiment of the piston of figure 3. It can be seen in figure 1 a distributor designated in its assembly with the reference 1, comprising a flexible reservoir 2, provided with a ring-clamp 4 whose periphery 6 is press-fitted, by a throat system 6a / impeller 6b on the upper part of a rigid external enclosure 8 which surrounds the flexible reservoir 2. The annulus 4 forms a cuvette 5 having I an external cylindrical lateral wall 5a and a transverse bottom 5b. the bag 2 and the enclosure 8. The center of the tub 5 is open and extends upwards in the central duct 10 which constitutes the base of a plunger 12. The central duct 10 forms a suction channel 11 of the product, whose first end is communicated with the reservoir, while the second end supports the piston 12. The piston 12 is hollow and is provided with a central hole 14 made in an elastic membrane 16 that has been deposited, by bi-injection of a material suitable elastomeric thermoplastic, for example, Santoprene® (EPDM, sold by the company MONSANTO) on the upper end of the plunger II 12. The plunger 12 has a general cylindrical shape, the end of the cylinder being provided with a circular sealing flange 12a and 12b (see figure 3) of thin thickness, of vanished lining on its free edge.

Advantageously, the plunger is made of a semi-rigid material, such as low density bolyethylene, capable of imparting some flexibility to the sealing lips 12a and 12b. A central protrusion 18 seals hole 14 in the resting state. The protrusion 18 is held in position by radial lugs 20 1 integral with the upper end 10a of the central duct . The upper end 10a rests on an annular stop 12c formed inside the piston 12, which allows an exact position of the membrane 16 with respect to the protrusion 18. The membrane lß and the protrusion form a valve intended for the intake of the product. P in a pumping chamber 22 of variable volume. This chamber 22 is defined by the internal volume of a cylindrical tube 24 forming part of a push button 26. The tube 24 has an internal diameter sufficient to allow a hermetic sliding of the plunger 12 and extends to half the height of the side wall 5a in the trough 5. The tube 24 comprises a circular plate 28 that extends radially outwardswhose periphery is bent into a square and thus forms a cylindrical skirt 30 apt to slide axially through the trough 5. Between the bottom of the trough 5 and the plate 28 there is disposed a helical metal spring 32, elastically compressible, a system having been provided double stop on the skirt 30 and on the upper part of the side wall 5a intended to keep the push button 26 in position inside the trough 5, this push-button then being axially movable against the pulling force of the spring The tube 24 is closed from its upper end by an oblique transversal surface 34 having a concave shape and on which the user places a finger for the distribution of the product P. The upper end I of the push button 26 presents, moreover, a dispensing orifice 36 communicating with the chamber 22 via a distribution channel 38. The dispensing orifice 36 is closed by an elastic flapper valve 40 capable of preventing re-entry of air into the pumping chamber 22 , although able to open under the push of product P from the pumping chamber. The push button 26 provided with the dispensing valve 40, and the ring 4 provided with the plunger 12 constitute a dispensing head 7. To distribute a dose of product P, it suffices to axially tighten the surface 34 of the pusher 26 in the direction of the fleóha F (see figure 1) to make the tube 24 descend to the bucket 5 and thus reduce the! volume of the pump chamber 22, compressing the spring 32. When this volume reduction takes place, a volume of air determined outside the chamber 22 is impelled through the dispensing orifice 36, rejecting the elastic valve 4C. By loosening the force on the button, the spring pulling force forces the spring to the initial position, which causes the depression to be created in the chamber 22. This depression is sufficient to separate the bracket 16 from the spring. central protrusion 18 and to suck a dose of the product P which is in the bag 2. When the chamber 22 is initially empty, successive pressures on the push-button 26 are sufficient to fill the chamber 22 with the product P and the distribution channel 38. Then, the aspirated product is expelled towards the outside by pushing the distribution valve 40. When the product is expelled, the excess pressure inside the chamber 22 keeps the intake valve 16 and 18 closed, gluing the membrane 16 on the protrusion 18. Figures 4 and 5 represent a second embodiment of the invention. The distributor 101, according to FIG. 4, is distinguished from that shown in FIG. 1 by the absence of the bolt, and comprises an intake valve of different construction. In Figure 4, the parts identical to those in Figure 1 bear the same reference numerals, the description not being made here rather than succinctly; the parts are different, but fulfill a mission similar to those of figure 1 and bear reference numbers increased by 100. As seen in figure 4, a product tank is delimited by a rigid external enclosure 8 of cylindrical section in which In the background, a follower piston 102a is arranged. When the distribution of the product P takes place, this piston 102a is able to move axially along the axis X towards the push button 26 under the action of a depression created by the variable volume chamber 22. The cylindrical enclosure 8 presents a added bottom 108b provided with a vent 108a. discontinuous, placed on a circular line and practiced in unites. elastically deformable membrane 116 established by gluing, press-fitting or by bi-injection of a suitable elastomeric material on the upper end c.the plunger 112. The plunger 112 has a general cylindrical shape, each end of the cylinder being provided with a rim circular seal 112a and 112b (see figure 5). Apart from the membrane 116, the plunger 112 is made of a rigid or semi-rigid material such as low density polyethylene, however, ensuring a relatively small thickness of the flanges 112a and 112b, a tight and smooth sliding by the cylindrical part 24 of push button 26. Advantageously, other parts of the dispenser 101, as the push button 26, the ring-clamp 4 and the rigid enclosure 8 are made of a rigid thermoplastic material such as polypropylene. The central duct 10 has an upper end provided with an annular edge 118 that forms a seat, whose diameter is determined so that the edge 118 completely seals the grooves 114a-114c, in an undeformed position of the membrane. The membrane: .16 and the annular rim 118 form a valve intended for the admission of the product P into the variable volume chamber 22. When excess pressure is present in the variable volume chamber 22, the product contained in the chamber 22 can not descend into reservoir 102, since the edges of slots 114a-114c of the membrane are tightly pressed against the seat 118. When, after distribution of a product dose, a depression is created in the chamber 22, the edges of the slots 114a-114c are detached from the seat 118, and the product P is sucked up. Figure 6 shows a variant embodiment of the piston of figure 3. The plunger 212 of figure 6 comprises two annular sealing rims 212a, 212b arranged on each end of the plunger. The thickness of these edges is decreasing so that the end zone intended to be in contact with the inner wall of the chamber, only has a thickness of a few hundredths of a millimeter. A membrane 216 made of elastomer provided with a central opening 214 is deposited in the upper part of the plunger, by bi-injection or by overmolding, in the membrane several radial slots 214a extending from the opening 214 to the proximity of the periphery of the membrane. With respect to the embodiment of figure 3, we will say that the piston of figure 6 has been conceived for a more important volume of product and a more flexible operation. On the other hand, the pumping system should not occupy more than a small volume, to allow its integration in a distributor. Thus, according to the invention, a pump comprising a plunger whose diameter is between 4 and 15 mm, and preferably between 5 and 10 mm, is advantageously used. This I allows the realization of a distributor of particularly compact, small height. From this perspective, it is possible, in particular, to realize the distribution head of particularly small dimension. According to another aspect of the invention, it is possible to realize distributors at a particularly advantageous cost price.

Claims (12)

1. Distribution head of a product of liquid or pasty consistency contained in a reservoir comprising a push button that moves axially, said push button having a body whose internal walls define a pumping chamber (22) of variable volume, which presents a input I for the product, sealed by a flapper valve of I j intake supported by a plunger presenting the plunger

at least one sealing flange in contact with which the inner walls move between one position

high and a low position, causing the passage of

high position and high position the aspiration of the

product to the pumping chamber through the 1 intake valve and causing the passage of the

high position to 'the low position with the output

of the product aspirated through a valve

distribution flap that closes an exit hole

of said chamber having provided elastic traction means to return the push button to the raised position, the intake valve being mounted as well as the piston over a ring-clamp that crowns said reservoir having said ring a seat

For the intake valve to prevent any return of product to the tank, characterized in that the plunger is formed by an annular part made of a rigid or semi-rigid material, and comprises a central part i that forms a single piece with the annular part, and is made in the form of a membrane of I an elastically deformable material, in which at least one opening has been made to form said valve.

2. Distribution head, according to claim 1, characterized in that said annular part ensures the assembly of the plunger on a feed channel that supports the aforementioned seat said annular part located outside the said feed channel.

3. Distribution head, according to one of claims 1 or 2, characterized in that the assembly of the membrane - on the seat is hermetic, at least when a pressure is exerted on said piston by the product 4.

Distribution head, according to claim 3, characterized in that the assembly of the membrane on the seat is permanently hermetic.

Head of the distribution, according to any of the preceding claims, characterized in that the annular part of the piston comprises a stop-forming portion, to ensure the exact positioning of the central part of the piston on the seat.

6. Distribution head, according to any of the preceding claims, characterized in that the intake valve and the

Annular part are made by bi-injection or overmolding of two compatible or non-compatible materials.

7. Distribution head, according to any of the previous claims, characterized in that the annular part has a thickness - decreasing in the direction towards its free end.

8. Distribution head according to any of the preceding claims, characterized in that the intake valve is constituted by a membrane having a variable thickness.

9. Distribution head according to any of the preceding claims, characterized in that the elastic deformable material is an elastomeric material. Distribution head according to any of the preceding claims, characterized in that said elastically deformable material is chosen from the elastomers of the propylene / ethylene copolymers; the polyether blocamide ?; the polyvinyl; the terpolymers of! ethylene, propylene and a diene (EPDM); the styrene-butadiene polymers sequenced (SBS); the styrene-ethylene-butadiene polymers sequenced (SEBS-SIS); the thermoplastic polyurethanes; mixtures of polypropylene with one of the following elastomers: sequenced styrene-ethylene-butadiene polymers (SEBS-SIS); terpolymers of ethylene, propylene and a diene

(EPDM); the styrene-butadiene polymers sequenced (SBS); silicone elastomers, butyl or nitrile rubbers, latexes or fluorinated elastomers. Distribution head according to any one of the preceding claims, characterized in that the elastically deformable material has a Shore A hardness comprised between 15 and 90. 12. Distribution head, according to any of the preceding claims, characterized in that the rigid material or semi-rigid is chosen among the polyethylenes of alite and low density, the polypropylenes, a feeding channel,, centered on the axis (X) of the distributor, and which ends on the intake valve of the distribution head being surrounded said feed channel by an annular portion 'forming a cavity around the feed channel, said cavity being delimited, on the opposite side to the feed channel, by an outer annular skirt carrying means for hooking onto the distributor. Distributor, according to claim 17, characterized in that said cavity has a transverse wall f | between the feed channel and the outer annular skirt, said elastic traction means being located between a protrusion formed by the push button and said transverse wall. 19. Dispenser according to claim 17 or 18, characterized in that the reservoir is constituted by a flexible bag having an open end integral with the ring-clamp and in communication with said feeding channel t cooperating the means of attachment with a end edge of an external or semi-rigid enclosure, containing said bag.

< *

20. Distributor according to claim 17 or 18, characterized in that the tank is constituted by a rigid or semi-rigid enclosure (8) in communication with e. '. feeding channel cooperating the engagement means with an end edge of said rigid or semi-rigid external enclosure, having a follower piston 1 in the bottom of the tank. 21. Distributor according to any of claims 16 to 20, characterized in that the

10 product is a cream, a gel or a liquid makeup.

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