EP2006028A1 - Pump for dispensing a liquid product with improved priming - Google Patents

Abstract

The pump (1) has a distribution head (3) that is movable on a pump body (2) between a rest position and a product delivering position. The head has a cylinder (4) forming a dosage chamber (41), and a channel (7) assuring a passage of a liquid product or air from the chamber towards an ejection orifice (8) of a push button (18). The button is arranged on a top part of the cylinder through a skirt (14), and actuates an axial displacement of the cylinder. A sealing base is fitted in the cylinder, while the channel is fitted between an outer wall of the cylinder and an inner wall of the skirt.

Description

The invention relates to a pump for dispensing liquid or semi-liquid product, designed in particular for closing a container containing the liquid product to be dispensed.

The pump according to the invention is particularly, but not exclusively, designed to be implemented in the pharmaceutical field.

The pumps generally used for the distribution of liquid or semi-liquid product are the pumps of the type called "needle pump". Such pumps comprise in the upper part a free mounted needle in displacement between a closed position where it closes the end opening of the pump, and prevents any product delivery, and an open position where it lets the liquid pass. through said end opening.

Such pumps comprise, in a conventional manner, a first pump chamber cylinder, which communicates with a setting tube via a check valve, and in which is slidably mounted a hollow piston. They also comprise a second cylinder, which communicates with the first cylinder, in which is slidably mounted a second piston constituted by a needle, able to interrupt the communication between the first cylinder and a dispensing nozzle. They finally comprise elastic means, of the metal spring type operating in compression, which act on the needle so as to maintain the latter in a closed position where said communication is interrupted.

The principle of operation of such pumps is as follows: when moving the first piston, the liquid in the first cylinder is discharged into the second cylinder in which the pressure rises. The second piston tends to sink into its cylinder by compressing the spring. When the pressure of the liquid reaches a value sufficient to balance this action, the second piston moves by driving the valve which is connected thereto, so that the cylinders are placed in communication with the dispensing nozzle.

Such pumps do not meet the current requirements for quality standards, because, for example, that the liquid product can be polluted by contact with the metal return spring of the needle in the closed position after dispensing the liquid product.

In addition, the doses of liquid product delivered are often not accurate, which limits the use of these pumps to the delivery of certain products.

In an attempt to overcome some of these disadvantages, it has been proposed in the patent application WO 2006/125880 , filed by the present Applicant, a pump comprising a needle consisting of a base surmounted by a rod, and a dispensing head manually movable on a pump body, between a rest position and a punctual delivery position of the liquid product . The head comprises elastic return means respectively said needle in the closed position of a dispensing orifice and the dispensing head in the rest position. The return means are arranged in the dispensing head so as not to. to be in contact with the liquid product to be dispensed. The dispensing head further comprises a channel ensuring the passage of the liquid product between the metering chamber and a second chamber formed at the end of said dispensing head so as to communicate with the orifice of the dispensing head. '

The opening of the dispensing orifice, allowing the ejection of the liquid product towards the outside of the pump, is performed under the action of the pressure exerted by the liquid product contained in the second chamber on the needle. More specifically, under the action of a pressure exerted by a user on the dispensing head, the liquid product contained in the metering chamber is compressed. This then exerts pressure on the liquid product contained in the channel, and indirectly on the liquid product contained in the second chamber. The liquid product contained in the second chamber, exerting pressure on the base of the needle, then compresses the elastic return means of the needle. Under this action, the stem of the needle deviates from the orifice of distribution, releasing a passage through which the liquid product is ejected to the outside of the pump.

This type of pump, however, requires, prior to dispensing the product, a priming, that is to say the evacuation of air that has been trapped in the metering chamber, in the channel and in the second chamber during of the pump assembly. The principle of evacuation of the air is similar to that of the distribution of the liquid product described above. However, the pressure exerted by the air contained in the second metering chamber is not always sufficient to allow to move the needle from the dispensing orifice and thus open the passage to eject the air out of the pump. It follows therefore difficulties priming the pump.

The invention aims in particular to overcome the disadvantages of the prior art described above, and more particularly those of the patent application. WO 2006/125880 , by proposing a pump whose priming is improved.

For this purpose, and according to a first aspect, the invention relates to a pump for dispensing liquid or semi-liquid product, intended in particular to be used in the pharmaceutical or cosmetic field, said pump comprising a pump body and a head dispensing device manually movable on the pump body, between a rest position and a point of product punctual delivery, the dispensing head comprising a cylinder forming a metering chamber of the pump, which chamber communicates with a liquid-collecting tube by via an intake valve means, said cylinder being slidably mounted in the pump body, and a channel for passage of product or air from the dosing chamber to an ejection port of the liquid product or air.

The pump is remarkable in that the dispensing head comprises an exhaust valve consisting of a rod slidably mounted inside the cylinder and whose lower end closes the dosing chamber in the upper part, the rod comprising means for sealing the channel consisting of a peripheral shoulder adapted to bear on a seat complementary sealing formed in the cylinder, the opening of the channel being effected by spacing the sealing seat of the cylinder opposite the shoulder of the rod after an advance abutment of the rod during the axial displacement of the cylinder in the pump body.

Advance abutment of the exhaust valve relative to that of the cylinder and allows to proceed to a mechanical opening of the pump. Indeed, the exhaust valve being stopped during an axial displacement with the cylinder, the sealing seat of the latter departs from the shoulder of the exhaust valve, thus opening the passage channel extending from the metering chamber to the ejection port of the pump.

Advantageously, the opening of the channel is achieved by abutment of the lower end of the rod against the inlet valve means, the cylinder continuing its axial displacement in the pump body. This configuration relates more specifically to the pre-evacuation phase of the air contained in the metering chamber (priming phase of the pump).

According to another configuration, the opening of the channel is achieved by abutment of the lower end of the rod under the action of the pressure exerted by the product contained in the metering chamber, the cylinder continuing its axial displacement in the pump body. This configuration relates more specifically to the distribution phase of the product contained in the metering chamber.

Advantageously, the exhaust valve is arranged with the cylinder to define a compartment in which is housed an elastic return means of the exhaust valve in the closed position of the channel, the compartment being isolated from the metering chamber by means of waterproof closure. Thus, the spring, which ensures a perfect sealing of the metering chamber at the top by pushing the exhaust valve against the sealing seat of the cylinder, is never in contact with the liquid product. Any risk of contamination of it is avoided. According to a particular configuration, the sealing means consist of a radial lip formed on the upper end of the outer wall of the rod.

Advantageously, the dispensing head comprises an air exhaust duct contained in the compartment during the manual movement of the dispensing head on the pump body, the exhaust duct being formed above the compartment. This duct makes it possible to evacuate the compressed air in the compartment during the axial displacement of the exhaust valve during the actuation of the pump. It will also control the tightness of the closure means insulating the compartment of the metering chamber.

Advantageously, the dispensing head comprises a push button for actuating the axial displacement of the cylinder in the pump body, said push button being fitted on the upper part of the cylinder by means of a first skirt. In a particular configuration, the channel is formed between the outer wall of the cylinder and the inner wall of the fitting skirt.

Advantageously, the pump comprises an elastic return means of the dispensing head in the rest position housed between the fitting skirt and a second skirt external to the fitting skirt. Such an arrangement has the advantage that the elastic return means is in contact with the product, thus avoiding any risk of contamination of the latter.

Advantageously, the pump comprises means for supporting and fixing on a liquid or semi-liquid product dispenser.

According to a second aspect, the invention relates to a liquid or semi-liquid product dispenser, for the purpose of a therapeutic or cosmetic treatment, provided with a pump according to any one of the preceding claims.

• la figure 1 illustre une vue en coupe d'une pompe selon l'invention en position de repos ;
• la figure 2 illustre une vue en coupe de la pompe de la figure 1 en position basse ;
• les figures 3 à 6 illustrent des vues en coupe de la pompe de la figure 1, représentée à différentes étapes de son actionnement au cours de la délivrance du produit fluide.

Other objects and advantages of the invention will become apparent from the following description, made with reference to the appended drawings, in which:

• the figure 1 illustrates a sectional view of a pump according to the invention in the rest position;
• the figure 2 illustrates a sectional view of the pump of the figure 1 in the low position;
• the Figures 3 to 6 illustrate sectional views of the pump of the figure 1 , represented at different stages of its actuation during the delivery of the fluid product.

In relation to the figures, the pump which will be described is particularly suitable for dispensing a liquid or semi-liquid product, pharmaceutical, in the form of nasal sprays. However, it is understood that the pump according to the invention may have different shapes and apply to other areas, such as that of cosmetics.

The pump 1 comprises a pump body 2 and a dispensing head 3 that can be moved manually on the pump body 2, between a rest position ( figure 1 ) and a low position ( figure 2 ).

The dispensing head 3 comprises a cylinder 4, forming a metering chamber 41, slidably mounted in the pump body 2 and an exhaust valve 9 constituted by a rod slidably mounted inside said cylinder 4. The metering chamber 41 is closed in the upper part by the exhaust valve 9, and communicates in the lower part with a liquid intake tube 5 via an intake valve 6.

The dispensing head 3 further comprises a pusher tip 18 fitted on the upper part of the cylinder 4. The pusher tip 18 comprises two concentric skirts 14, 15, a first skirt 14, called an inner skirt, surrounding the cylinder 4, and a second skirt 15, said outer skirt, arranged spaced from the first skirt 14.

The pusher tip 18 is provided with an orifice 8 through which is ejected, outside the pump, the air contained in the metering chamber during the priming phase or the dose of product to be dispensed. To do this, the passage of the fluid from the metering chamber 41 to the orifice 8 takes place through a channel 7. In the embodiment described, the channel 7 is formed between the outer wall of the cylinder 4 and the inner wall of the first skirt 14.

The dispensing head 3 further comprises means for sealing the channel 7, preventing the passage of the fluid (air or liquid product to be dispensed) from the metering chamber 41 to the delivery orifice 8 of the dispensing head. The closure means consist of a shoulder 10 formed on the outer wall of the rod adapted to bear on a sealing seat 11, of complementary shape, formed in the cylinder 4. Thus, and as will be seen later, the sealing of the channel 7 is achieved by maintaining the shoulder 10 of the rod on the sealing seat 11 of the cylinder 4, its opening being effected by spacing the sealing seat 11 from the cylinder 4 opposite the shoulder 10.

The bearing support of the shoulder 10 of the rod on the sealing seat 11 of the cylinder 4 is formed by a resilient biasing means 12 of the spring type. This is housed in a compartment 42 defined by the cylinder 4 and the upper end of the rod. The spring 12 is mounted in compression in the compartment 42.

In order to prevent the spring 12 from coming into contact with the fluid coming from the metering chamber 41, the compartment 42 is isolated from the latter by sealing means 92. In the embodiment described, the means of sealing 92 consists of a radial lip 92 formed on the upper end of the outer wall of the rod.

Advantageously, the exhaust valve 9 is arranged in the cylinder 4 so as to have, when it is held against the sealing seat of the cylinder 4, in the rest position, a low end 91 extending into the chamber of dosage 41.

Advantageously, the dispensing head 3 comprises a duct 13 intended to evacuate the air contained in the compartment 42 during the manual movement of the dispensing head 3 on the pump body 2 as well as to allow the tightness of the means to be checked. closure 92 during industrial assembly. In the embodiment described, the duct 13 extends above the compartment 42.

Furthermore, the pump is provided with a second resilient biasing means 16, of the spring type, intended to ensure the elastic return of the dispensing head 3 in the rest position. In order to prevent the liquid from coming into contact with and being contaminated by the spring 16, the spring 16 is advantageously housed between the inner skirt 14 and the outer skirt 15 of the push button 18.

In the embodiment described, the intake valve 6 consists of a deformable membrane 19 formed in the lower part of the pump body 2. The membrane 19 rests on a tubular support 20 rising in the lower part of the pump body 2.

The lower end of the support 20 is provided with an external radial extension 21. As will be seen below, the extension 21 has the role of abutting the cylinder 4 moving axially in the pump body 2, the abutment of said cylinder 4 corresponding to the lower position of the pump 1.

The upper end of the support 20 is provided with a contact pad 22. The membrane 19, comprising an orifice 23, covers the upper end of the support 20, the orifice 23 being disposed opposite the contact stud. contact 22. In addition to the function of closing the orifice 23 of the membrane 19, the contact pad 22 also has the function of abutting the exhaust valve 9 for the purpose of priming the pump.

The support 20 is fitted on the outside of a hollow cylindrical portion 24 of the pump body 2, which cylindrical portion 24 extends inside said pump body 2 and opens on the lower part thereof. The tube of intake 5 of the liquid product contained in the dispenser is fitted through the inside of the cylindrical portion 24 of the pump body 2.

The pump further comprises support and fixing means 17 to allow its attachment to a dispenser containing the liquid or semi-liquid product to be dispensed.

The operation of the pump will now be described.

Prior to the delivery of the product contained in the dispenser provided with a pump as described above, it is necessary to evacuate the air trapped in the metering chamber 41 of said pump. This is the so-called priming phase.

The operating principle of this phase, represented by figures 1 and 2 is the following: under the action of a manual pressure P (illustrated by an arrow on the figure 1 ) on the push button 18 of the dispensing head 3, the cylinder 4 - exhaust valve 9 slides axially in the pump body 2 towards the inlet valve 6. The air, trapped in the chamber of dosage 41 sealed in the upper part by the exhaust valve 9 resting on the sealing seat 11 of the cylinder 4 and in the lower part by the inlet valve 6, is then compressed. The cylinder assembly 4 - exhaust valve 9 continues its stroke until the lower end 91 of the exhaust valve 9 comes into abutment against the contact pad 22 of the membrane support 20. The valve 9 thus maintained in standstill, the cylinder 4 continues its stroke alone until its lower end 43 reaches the extension 21 of the membrane support 20. The dispensing head 3 is then in the low position (or end of stroke position) ( figure 2 ).

Continuing its travel, the cylinder 4 moved away from the shoulder 10 of the exhaust valve 9, breaking the seal maintained until now by the contact between the exhaust valve 9 and the cylinder 4. The channel 7 is then open.

The seal broken, the compressed air in the metering chamber 41 can then escape from the metering chamber 41 to the orifice 8 through the open channel 7.

Once the low position is reached, the pressure P exerted on the push button 18 of the dispensing head 3 is released. Under the action of the spring 16, the push button 18 rises to its rest position, driving with it the raising of the cylinder 4 by sliding in the pump body 2. On its ascent, the sealing seat 11 of the cylinder 4 again comes into contact with the shoulder 10 of the exhaust valve 9, the cylinder 4 driving in its stroke said valve. The sealing of the metering chamber 41 is then again ensured by means of the spring 12, the latter pushing the exhaust valve 9 against the sealing seat 11 of the cylinder 4.

The rise of the dispensing head 3 continues, a vacuum is created in the metering chamber 41 sealed in its upper part. When the depression created in the metering chamber 41 is greater than the force maintaining the seal of the membrane 19 on the contact pad 22 of the membrane support 20, the membrane 19 deforms and the liquid product contained in the distributor is sucked from the distributor tank to the metering chamber 41 by the tube 5 for taking liquid. When the dispensing head 3 reaches the rest position, the depression in the metering chamber 41 ceases and the diaphragm 19 returns to the sealed position on the contact pad 22 of the membrane support 20.

This operation is repeated until complete evacuation of the air contained in the metering chamber 41. The priming phase is completed when the air contained in the metering chamber is entirely replaced by the product to be delivered. The product contained in the metering chamber 41 then corresponds to a dose of product to be delivered.

The priming phase completed, the pump 1 enters its phase of product distribution, called liquid phase. The liquid phase is illustrated on the Figures 3 to 6 .

Under the action of manual P downward pressure (illustrated by an arrow on the figure 4 ) on the push button 18 of the dispensing head 3, the cylinder assembly 4 - exhaust valve 9 slides again in the pump body 2 in the direction of the inlet valve 6. However, under the action of the pressure exerted by the product contained in the metering chamber 41, the exhaust valve 9 is retained in its race. The cylinder 4, continuing only its stroke, then departs from the shoulder of the exhaust valve 9, thus breaking the seal of the valve with the sealing seat 11 of the cylinder 4. The channel 7 is then open.

The seal broken, the product contained in the metering chamber 41 can then pass into the channel 7 open to be expelled from the pump 1 through the orifice 8 ( figure 4 ).

The cylinder 4 and the exhaust valve 9, kept apart from each other under the action of the product contained in the metering chamber 41, jointly continue their stroke, until the bottom end of the cylinder 4 reaches the extension 21 of the membrane support 20. The low position of the dispensing head 3 then corresponds to the complete delivery of the dose of product contained in the metering chamber 41 ( figure 5 ).

Once the low position is reached, the pressure P exerted on the push button 18 of the dispensing head 3 is released. As for the priming phase, the push button 18 rises to its rest position under the action of the spring 16, causing with it the upward sliding of the cylinder 4 in the pump body 2. When it rises, the seat 11 of the cylinder 4 again comes into contact with the shoulder 10 of the exhaust valve 9, the cylinder then driving in its stroke the exhaust valve 9. The sealing of the metering chamber 41 is then at again ensured by the spring 12, the latter pushing the exhaust valve 9 against the sealing seat 11 of the cylinder 4.

The rise of the dispensing head continuing, a vacuum is created in the metering chamber 41 sealed in its upper part.

When the depression created in the metering chamber 41 is greater than the force maintaining the seal of the membrane on the contact pad 22 of the membrane support 20, the membrane 19 deforms and the product contained in the distributor is sucked from the dispenser reservoir to the metering chamber 41 through the liquid-collecting tube 5 ( figure 6 ). When the dispensing head 3 reaches its rest position, the depression in the metering chamber 41 ceases. The membrane 19 then returns in a sealed position on the pad 22 of the membrane support 20 ( figure 3 ).

The invention is described in the foregoing by way of example. It is understood that the skilled person is able to achieve different variants of the invention without departing from the invention.

Claims (9)

Pump (1) for dispensing liquid or semi-liquid product, intended in particular for use in the pharmaceutical or cosmetic field, said pump (1) comprising a pump body (2) and a displaceable dispensing head (3) manually on the pump body (2), between a rest position and a point-in-time delivery position of the product, the dispensing head (3) comprising; a cylinder (4) forming a metering chamber (41), said chamber communicating with a liquid-collecting tube (5) via an inlet valve means (6), said cylinder (4) being slidably mounted in the pump body (2), - a channel (7) ensuring the passage of the product or air from the metering chamber (41) to an ejection port (8) of the liquid product or air, - An exhaust valve (9) consisting of a rod whose lower end closes the metering chamber (41) in the upper part and which comprises sealing means of the channel (7) consisting of a shoulder (10) peripheral adapted to bear on a sealing seat (11), the opening of the channel (7) being effected by spacing the shoulder from the seat (11) of the cylinder (4) after an early stop of the rod during the axial displacement of the cylinder (4) in the pump body (2) and, - a push button (18) fitted on the upper part of the cylinder (4) by means of a first skirt (14) and intended to actuate the axial displacement of the cylinder (4), characterized in that said sealing seat (11) is formed in the cylinder (4) while the channel (7) is formed between the outer wall of the cylinder (4) and the inner wall of the first skirt (14). Pump (1) according to claim 1, characterized in that the opening of the channel (7) is achieved by the early abutment of the lower end (91) of the rod against the inlet valve means (6). ). Pump (1) according to claim 1, characterized in that the opening of the channel (7) is achieved by the early abutment of the lower end (91) of the rod under the action of the pressure exerted by the product contained in the dosing chamber (41). Pump (1) according to any one of the preceding claims, characterized in that the exhaust valve (9) is arranged with the cylinder (4) to define a compartment (42) in which is housed an elastic return means ( 12) of the exhaust valve (2) in the closed position of the channel (7), the compartment (42) being isolated from the metering chamber (41) by sealing means (92). Pump (1) according to the preceding claim, characterized in that the sealing means (92) consist of a radial lip formed on the upper end of the outer wall of the rod. Pump (1) according to one of the preceding claims, characterized in that it comprises an elastic return means (16) of the dispensing head (3) in the rest position housed between the skirt (14) of fitting and a second skirt (15) external to the skirt (14) of fitting. Pump (1) according to any one of claims 4 to 6, characterized in that the dispensing head (3) comprises an exhaust duct (13) contained in the compartment (42) during the manual movement of the dispensing head (3) on the pump body (2), the exhaust duct (13) being arranged above the compartment (42). Pump (1) according to any one of the preceding claims, characterized in that it comprises support and fixing means (17) on a liquid or semi-liquid product dispenser. Liquid or semi-liquid product dispenser, for the purpose of a therapeutic or cosmetic treatment, provided with a pump (1) according to any one of the preceding claims.

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