EP3898003B1 - Device for dispensing a fluid product - Google Patents

Description

The present invention relates to a fluid dispenser pump.

The documents FR2343137 And FR2403465 describe a device comprising a pump comprising a pump body in which a piston can move, slidably mounted on an actuating rod, the thrust force exerted on the rod by the user being transmitted to the piston by means of a spring, so that by actuating the actuating rod, there is a relative movement of the piston with respect to the rod.

However, this pump has certain drawbacks. Thus, the dose dispersion between successive doses is relatively large. In particular, in the event of non-axial actuation by the user, the operation of the pump can be negatively impacted.

The documents WO9201183 , US4856677 , WO2004054724 And EP1506818 describe other prior art devices.

The object of the present invention is to provide a fluid dispenser pump which does not reproduce the aforementioned drawbacks.

The present invention also aims to provide a fluid dispenser pump which improves dose reproducibility between successive doses.

Another object of the present invention is to provide a fluid dispenser pump which improves operating reliability, in particular in the case of non-axial actuation.

The present invention also aims to provide a fluid dispenser pump that is simple and inexpensive to manufacture and assemble.

• un corps de pompe, comportant une ouverture obturée par un clapet d'entrée, maintenu en place par un porte-clapet fixé dans ledit corps de pompe,
• un piston coulissant de manière étanche dans ledit corps de pompe, autour d'une tige creuse, pourvu d'un canal axial interne fermé axialement du côté inférieur de ladite tige et communiquant avec l'extérieur de la tige par un orifice radial, ledit piston comportant sur un bord radialement externe une lèvre d'étanchéité externe pour assurer l'étanchéité contre ledit corps de pompe, et sur un bord radialement interne une lèvre d'étanchéité interne, pour assurer l'étanchéité contre ladite tige,
• un fouloir coopérant avec ladite lèvre d'étanchéité interne dudit piston,
• un ressort d'actionnement disposé entre ladite tige et ledit piston,
• un ressort de rappel disposé entre ledit porte-clapet et ladite tige, sollicitant ledit piston vers sa position de repos,

ledit porte-clapet comportant un manchon axial recevant ladite tige en position d'actionnement, ledit manchon axial comportant au moins une nervure axiale, pour former une butée mécanique en position d'actionnement de la pompe entre l'extrémité axiale inférieure de ladite tige et ladite au moins une nervure axiale dudit porte-clapet.The present therefore relates to a fluid dispenser pump comprising:

• a pump body, comprising an opening closed off by an inlet valve, held in place by a valve holder fixed in said pump body,
• a piston sliding in sealed manner in said pump body, around a hollow rod, provided with an internal axial channel closed axially on the lower side of said rod and communicating with the outside of the rod by a radial orifice, said piston comprising on a radially outer edge an outer sealing lip to seal against said pump body, and on a radially inner edge an inner sealing lip, to seal against said rod,
• a rammer cooperating with said internal sealing lip of said piston,
• an actuating spring disposed between said rod and said piston,
• a return spring disposed between said valve holder and said rod, urging said piston towards its rest position,

said valve holder comprising an axial sleeve receiving said rod in the actuating position, said axial sleeve comprising at least one axial rib, to form a mechanical stop in the pump actuating position between the lower axial end of the said rod and said at least one axial rib of said valve holder.

Advantageously, said axial sleeve comprises at least two axial ribs.

Advantageously, four axial ribs extend two by two in a diametrically opposite manner around an axial opening of said valve holder.

Advantageously, a passage hole is formed in said axial sleeve to ensure the passage of the liquid in the actuating position.

Advantageously, a fixing ring is provided to fix said pump body to a container with the interposition of a neck gasket, a ring gasket being provided to seal said fixing ring with said pump body.

Advantageously, in the rest position, an upper axial edge of said piston cooperates in leaktight manner with said ring seal.

Advantageously, a vent is provided in said pump body to allow the replacement by air of the product expelled by the pump on each actuation.

The present invention also relates to a fluid dispenser device comprising a pump as described above.

• la figure 1 est une vue schématique en section transversale d'une pompe de distribution de produit fluide de l'art antérieur, en position de repos,
• la figure 2 est une vue schématique similaire à celle de la figure 1, en position d'actionnement,
• la figure 3 est une vue schématique en section transversale d'une pompe de distribution de produit fluide selon un mode de réalisation avantageux de l'invention, en position de repos,
• la figure 4 est une vue schématique similaire à celle de la figure 3, en position d'actionnement,
• la figure 5 est une vue schématique partielle agrandie d'une partie de la pompe de la figure 4, et
• la figure 6 est une vue schématique en perspective d'un porte-clapet Dans la description, les termes "supérieur", "inférieur", "haut" et "bas" se réfèrent à la position droite du dispositif représentée sur les figures 1 à 4. Les termes "axial" et "radial" se réfèrent à l'axe central vertical A de la pompe, représenté sur la figure 1.

These characteristics and advantages and others will appear more clearly during the following detailed description, made with reference to the attached drawings, given by way of non-limiting examples, and on which:

• there figure 1 is a schematic cross-sectional view of a prior art fluid dispenser pump, in the rest position,
• there picture 2 is a schematic view similar to that of the figure 1 , in the actuated position,
• there picture 3 is a schematic cross-sectional view of a fluid dispenser pump according to an advantageous embodiment of the invention, in the rest position,
• there figure 4 is a schematic view similar to that of the picture 3 , in the actuated position,
• there figure 5 is an enlarged partial schematic view of part of the pump of the figure 4 , And
• there figure 6 is a schematic perspective view of a valve holder. In the description, the terms "upper", "lower", "top" and "bottom" refer to the upright position of the device shown on the figures 1 to 4 . The terms "axial" and "radial" refer to the central vertical axis A of the pump, shown in the figure 1 .

Referring to the figures, the pump comprises a pump body 14.

A fixing ring 10 is provided to fix the pump body 14 on the neck of a container (not shown) with the interposition of a neck gasket 11. A ring gasket 13 seals the fixing ring 10 with the pump body 14.

A piston 16 slides in leaktight manner in the pump body 14, around a hollow rod 15, with an internal axial channel 15a.

A radially outer edge of piston 16 forms an outer sealing lip 16a, to seal against the inner surface of pump body 14.

An upper axial edge 16b of piston 16 seals against ring seal 13 when at rest.

The internal axial channel 15a opens axially towards the top of the rod 15. Towards the bottom, the channel 15a is axially closed and communicates with the outside of the rod via a radial orifice 15b.

The pump body 14 is closed at the bottom by an inlet valve 20, held in place by a valve holder 21. This inlet valve closes an opening 29, communicating with the interior of the container, and on which one can connect a dip tube 29a, in the well-known conventional manner.

The rod 15 has a shoulder 23, against which bears an actuating spring 24 applied on the other side against the piston 16. This actuating spring 24 serves to transmit the pressure force from the rod 15 to the piston 16 The shoulder 23 also serves to limit the upward movement of the rod 15, forming an abutment with the ring seal 13.

A return spring 25 urges the piston 16 upwards, and, with it, the rod 15 via the actuation spring 24.

When the pump is at rest, the upper edge 16b of the piston 16 is applied against the ring seal 13.

The seal between the piston 16 and the rod 15 is provided by an internal part of the piston 16, preferably of conical shape, forming an internal sealing lip 31. To improve the seal, it is still possible, if necessary in certain cases (for example, very fluid product or high pressure required) provide an extension 16c of the piston towards the top of the rod 15.

At rest, the orifice 15b is in line with the lip 31, so as to be completely closed. The seal between the outside and the inside of the container is therefore ensured on the one hand by the contact between the edge 16b and the seal 13, on the other hand between the internal sealing lip 31 and the rod 15.

To improve the tightness and to improve the working conditions of the lip 31, the pump comprises a support piece or rammer 32, better visible on the figure 5 , and comprising upwards an oblique or frustoconical surface 32a of suitable inclination with respect to that of the internal sealing lip 31 of the piston 16.

The force exerted by the return spring 25 on the piston 16 is thus transmitted by the rammer 32.

The lower surface 32b of the gland 32 serves as a stop against the valve holder 21, to limit the travel of the piston 16 downwards.

At rest, the force exerted by the return spring 25 must be greater than that which is exerted by the actuating spring 24, so that the upper edge 16b of the piston 16 is properly applied to the ring seal 13. When one presses on the rod 15, the force exerted by the actuating spring 24 increases rapidly and substantially exceeds the force exerted by the return spring 25 so that the difference in the thrusts exerted by the springs 24, 25 corresponds to the desired pressure in the lower part of the pump casing 14.

A vent 35 is provided in the pump body 14 to allow the replacement by air of the product expelled by the pump on each actuation.

The pump described above works as follows. At rest, sealing inside the container is ensured by the neck gasket 11 between the ring 10 and the container (not shown), by the ring gasket 13 between the ring 10 and the pump body 14, by the contact between the upper edge 16b of the piston 16 and the ring seal 13, and by the internal sealing lip 31 of the piston 16 against the rod 15.

The container, not shown in the drawings, and which can be arbitrary, is filled with a liquid, in particular pharmaceutical, to be dispensed, in particular to be sprayed.

The fixing ring 10 can be made of metal or plastic. It can be crimped, screwed, snapped or otherwise attached to the container.

The user must first prime the pump by running it to expel air until the lower part of the pump body 14 is filled with liquid.

The user then pushes the rod 15. The liquid being practically incompressible, the piston 16 will move little and the actuating spring 24 will compress. The pressure of the liquid increases all the more as the lower end of the rod 15 sinks into the pump body 14. When the pressure manages to equalize the force of the actuating spring 24, unlike the force return spring 25, piston 16 no longer descends and rod 15, continuing to sink, uncovers orifice 15b below sealing lip 31.

The liquid is rapidly expelled through the orifice 15b and the channel 15a, towards a dispensing head (not shown) assembled on the pump, and the pressure is kept constant during this operation, by the actuating spring 24, which exerts the desired pressure as the orifice 15b is open. As soon as the pressure exerted by the user is reduced, or when the lower surface 32b of the gland 32 abuts against the seal carrier 21, the piston 16, actuated by the actuating spring 24 closes off the orifice 15b. The distribution stops, it is therefore entirely carried out under constant pressure, pressure determined exactly by the choice of springs.

After which, the user ceases to exert pressure on the rod 15. The actuating spring 24 relaxes immediately, which ensures the closure of the orifice 15b, and the return spring 25 brings the assembly back towards the top. Liquid is sucked in through orifice 29, by lifting valve 20, while air replaces this liquid, passing through the central opening of ring seal 13 around stem 15, and through vent 35 When the upper edge 16b of the piston 16 comes into contact with the ring seal 13, the air can no longer enter, and the piston 16 is blocked, the pump has returned to its rest position and is ready for a new actuation.

The gland 32 makes it possible to obtain an excellent seal with an internal sealing lip 31 made in the mass of the piston 16, that is to say in an inexpensive material, which does not require high precision of the characteristics over time and temperature. The choice of the size of the rammer 32, in particular its axial length, makes it possible to adjust the stroke of the piston 16, that is to say the volume of the dose dispensed at each actuation. It is therefore possible, with a single model of pump, to obtain very different doses by an appropriate choice of the length of the rammer.

A disadvantage of the prior art pump shown in the figures 1 and 2 relates to dose dispersion.

Thus, the volume of the dose is defined by the volume displaced by the piston 16 and ram 32 subassembly on the one hand, and by the volume displaced by the rod 15 on the other hand. Calculations have established that 88% of the geometric dispersion of the dose comes from the volume displaced by the piston 16 and gland 32 subassembly, and 12% of this geometric dispersion comes from the volume displaced by the rod 15.

However, a drawback of the pump of the prior art represented on the figures 1 and 2 relates to operational reliability under non-axial actuation.

Thus, the actuation limit stop of the rod is produced by the actuation spring 24 which is completely compressed, with the contiguous turns. It is therefore a deformable component, because even with contiguous turns, the actuating spring 24 remains relatively flexible. The end of dose is therefore dependent on a deformable component, and on variations according to the user's actuation force and/or the precision of the spring.

Moreover, the piston 16, being in contact with the walls of the pump body 14 only by the sealing lip 16a, cannot ensure good guidance of the rod. The gland 32, not being in contact with the walls of the pump body 14, does not allow this to be remedied.

A non-axial actuating force exerted on the rod 15 therefore passes through the actuating spring 24 with contiguous turns and through the cone-on-cone contact between the internal sealing lip 31 of the piston 16 and the oblique surface 32a of the gland 32 , these flexible elements being liable to deform, which generates a malfunction of the pump in the actuation position, also called tilting, liable to generate an undesired modification of the volume of the dose dispensed.

According to the invention, a mechanical stop of the pump is provided between the lower axial end 15c of the rod 15 and the valve holder 21, to define the end of actuation stroke of the rod 15. For this purpose, said valve holder 21 comprises at least one axial rib 21a formed in an axial sleeve 21c receiving the rod 15 in the actuating position. To ensure the passage of the liquid beyond said contact, a passage hole 21b is formed in said axial sleeve 21c, as visible on the figure 6 .

Preferably, four axial ribs 21a are provided, as seen on the figure 6 . These axial ribs 21a can extend two by two in a diametrically opposite manner around an axial opening 21d of said valve holder 21.

This stop formed by the contact, in the actuation position, between the ribs 21a of the valve holder 21 and the lower axial end of the rod 15, ensures a transmission of the actuation force directly from the rod 15 to the body pump 14, via the valve holder 21, without risk of deformation of the flexible elements of the pump defining the dose volume. The reproducibility of the dose is therefore improved and the risk of tilting reduced.

Comparative tests between the pump of the prior art of figures 1 and 2 and the pump of the invention of figures 3 to 6 were performed and are shown in the table below. [Table 1] Prior art Invention Average dose 96.2µl 90.6µl Standard deviation 7.6µl 3.9µl

It is noted that the present invention generates a slightly lower average dose in volume, but that the standard deviation, that is to say the dose dispersion, is greatly reduced with the present invention. In this case, this dose dispersion is reduced by 48%, which demonstrates the effectiveness of the present invention, with the reproducibility of the dose between successive actuations being greatly improved.

The present invention has been described with reference to an advantageous embodiment, but it is understood that a person skilled in the art can make any modifications thereto, without departing from the scope of the present invention as defined by the appended claims.

Claims (8)

1. A pump for dispensing a fluid product comprising:

   - a pump body (14), comprising an opening (29) closed by an inlet valve (20), held in place by a valve holder (21) fastened in said pump body (14),

   - a piston (16) sliding in a sealed manner in said pump body (14), around a hollow rod (15), provided with an inner axial channel (15a) axially closed on the lower side of said rod (15) and communicating with the outside of the rod (15) via a radial orifice (15b), said piston (16) comprising, on an outer radial edge, an outer sealing lip (16a) for ensuring the sealing with respect to said pump body (14), and on an inner radial edge, an inner sealing lip (31), for ensuring the sealing with respect to said rod (15),

   - a gland (32) cooperating with said inner sealing lip (31) of said piston (16),

   - an actuating spring (24) disposed between said rod (15) and said piston (16),

   - a return spring (25) disposed between said valve holder (21) and said rod (15), biasing said piston (16) towards its rest position,

   characterized in that said valve holder (21) comprises an axial sleeve (21c) receiving said rod (15) in the actuating position, said axial sleeve (21c) comprising at least one axial rib (21a), for forming a mechanical stop in the actuating position of the pump between the lower axial end (15c) of said rod (15) and said at least one axial rib (21a) of said valve holder (21).
2. The pump according to claim 1, wherein said axial sleeve (21c) includes at least two axial ribs (21a).
3. The pump according to claim 2, wherein four axial ribs (21a) extend two by two in diametrically-opposite manner around an axial opening (21d) of said valve holder (21).
4. The pump according to any one the preceding claims, wherein a through hole (21b) is formed in said axial sleeve (21c) to ensure the passage of the liquid in the actuating position.
5. The pump according to any one of the preceding claims, wherein a fastening ring (10) is provided for fastening said pump body (14) on a container with a neck seal (11) interposed therebetween, a ring seal (13) being provided for ensuring the sealing of said fastening ring (10) with said pump body (14).
6. The pump according to claim 5, wherein, in the rest position, an upper axial edge (16b) of said piston (16) cooperates in a sealed manner with said ring seal (13).
7. The pump according to any one the preceding claims, wherein a vent (35) is provided in said pump body (14) to allow the product expelled by the pump to be replaced by air on each actuation.
8. A product fluid product dispensing device, characterized in that it includes a pump according to any one of preceding claims.

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