EP0544549A1 - Pump for the delivery of a product, liquid or paste-like, and dispenser-container with such a pump - Google Patents

Abstract

The pump (1) comprises a pump body (4) intended to be mounted on a container (2) containing the product (P) to be dispensed and a push button (12) suitable to be pushed in against elastic return means (31) in order to dispense the product, the said pump including a precompression valve suitable for allowing the product to be dispensed only when a sufficient pressure is reached, air-compressing means being furthermore provided in order to blow air through the nozzle (13) after dispensing the product. The air-compressing means (12, 24) are arranged so as to blow air, through the nozzle (13), during the phase when the push button (12) rises up under the action of the elastic return means (31); during the phase when the push button (12) is lowered, the aforementioned air-compressing means (24) suck air in with a view to subsequently expelling it, while a metered amount of product (P) is dispensed through the nozzle (13). <IMAGE>

Description

The invention relates to a pump for dispensing a product, liquid or pasty, through a dispensing nozzle, a pump of the type which includes: a pump body intended to be mounted on a container containing the product to be distribute; a push button rises slidingly relative to the pump body and suitable for being pressed, against elastic return means, to cause the distribution of the product; a precompression valve provided to allow this distribution of the product only when sufficient pressure is reached; and air compression means provided for expelling air through the nozzle after dispensing the product in order to purge the outlet duct.

Such a pump, called a self-purging pump, aims to reduce the clogging problems which arise due to the drying of the product remaining in the distribution channel of the pump. This drawback is particularly important in the case of lacquer or cream pumps. In the case of a cream is added to the problem of plugging by drying, the problem of contamination of the remaining product.

FR-A-2 434 943 shows, in particular in FIG. 3, a pump of this type. By pressing the push button, a liquid is precompressed in a chamber until a precompression valve opens allowing dispensing by spraying. Pressing the push button also makes it possible to compress the air under this push button and, at the end of pressing the push button, a passage is opened to the compressed air which can expel the remaining liquid through the nozzle Release.

A pump according to this document is relatively complicated and, when it is at rest, the passage intended to open for compressed air can become blocked. Indeed, this passage is occupied by the liquid when the pump is at rest and there may be drying of this liquid leading to an obstruction of said passage. In addition, the amplitude of the push button stroke during which the compressed air ensures the liquid purge is relatively low.

The object of the invention is, above all, to provide a self-draining pump of the kind defined above which is of a simple construction, which makes it possible to carry out an effective purging of all the pipes through which the liquid passes, which facilitates the arrival the purge air in these pipes and which reduces the opportunities for contact between the liquid contained in the pump body and the purge air. It is further desirable that such a pump has a great smoothness of operation and allows to easily start the distribution.

According to the invention, a pump for the distribution of a liquid or pasty product, through a distribution nozzle of the kind defined above is characterized in that the air compression means are arranged to expel the air, through the nozzle, during the ascent phase of the push button under the action of the elastic return means, and that during the descent phase of the push button the above compression means carry out an air suction in order to its subsequent expulsion, while a dose of product is distributed through the nozzle.

The air compression means advantageously comprise means for admitting air into a compartment of the pump body and means making it possible to evacuate this air through the normal pipes of the pump when the push-button is raised. .

Preferably, the air intake means are arranged to ensure the entry of air into the compartment at the end of depressing the push button.

The pressure relief valve is advantageously arranged to cut the communication between the air compression means and the product outlet channel when said valve allows the product to be dispensed through said outlet channel.

Preferably, the pump body comprises a cylindrical part in which a rod can be moved in longitudinal sliding, linked to the push button, which has a channel longitudinal opening, in the upper part, into a pipe leading to the nozzle and communicating, at its lower part, by at least one radial passage with the lateral surface of the rod, the pressure relief valve comprising a piston mounted to slide around the rod, at the level of the radial passage, between two stops, this piston sealingly separating the pump body into two compartments, namely an air compartment situated above the piston and a product compartment situated below the piston, the piston being able to take a high position for which the product compartment communicates with the aforesaid radial passage, while the air compartment is separated therefrom, and a low position for which the product compartment is separated from the radial passage while the air compartment is connected at this radial passage.

The product compartment is fitted with a suction valve and has a nozzle in the lower part to which a dip tube is connected.

The rod of the push-button advantageously comprises a collar located above the piston and a precompression spring is disposed between this collar and the piston, this spring tending to push the piston against the lower stop to keep it in the low position. . When the product to be dispensed is a liquid, this precompression spring can be relatively stiff while when the product to be dispensed is a paste, this spring has a very low stiffness.

The elastic return means of the push button comprise a spring disposed between the lower end of the rod and the bottom of the pump body equipped with the product suction valve and the dip tube.

The rod of the push-button slides, in the upper part, in a sealed manner in a cap closing the pump body, and this rod comprises, towards the top, an air intake means allowing an air entry into the compartment. air pressure while pushing the button.

The air intake means may comprise a longitudinal groove formed on the upper part of the rod.

As a variant, the air intake means comprises an upper part, of the rod, of smaller diameter sliding in a kind of sleeve extending upwards a cap closing the pump body.

The pump may include, between the air compartment cover and the fixing capsule on the container, an air intake channel allowing air to enter the container as the product is evacuated.

Advantageously, the lower part of the product compartment has a constricted zone capable of stopping the piston at the end of the push button depressing stroke in order to move it into the high position and facilitate priming of the pump by evacuation of the air. parasite in the product compartment at the start of pumping.

The invention also relates to a product dispenser container, liquid or pasty, equipped with a pump as defined above.

The invention consists, apart from the arrangements set out above, of a certain number of other arrangements which will be more explicitly discussed below in connection with exemplary embodiments described with reference to the attached drawings, but which are in no way limiting.

Figure 1 of these drawings is a vertical axial section of a self-draining pump, according to the invention, and of the upper part of a container equipped with such a pump, shown in the rest position.

Figure 2 shows, similarly to Figure 1, the pump while the push button is being pressed.

Figure 3 shows, similarly to Figure 1, the pump during the ascent of the push button.

Figure 4 is an axial vertical section of an alternative embodiment of the pump, shown in the rest position.

Figure 5 shows the pump of Figure 4 while the push button is being pressed.

Figure 6, finally, shows, in vertical axial section, the pump of Figure 4 at the end of depressing the push button, at the time of priming.

Referring to Figure 1, we can see a pump 1 for dispensing a product P, liquid or pasty, contained in a container 2 whose upper end forms a neck 3 provided with an outer peripheral bead. The pump 1 comprises a pump body 4 fixed to the neck 3 using a crimping ring 5.

The pump body 4 is constituted by a cylindrical part, open at its upper end and provided, on its upper periphery, with a rib 6 snap-fastening in a groove of a cap 7 covering the upper part of the body 4. A sealing washer 8, forming an internal seal, is clamped between the upper end of the body 4 and the cap 7

This cap is provided with a collar 9 projecting radially outwards. A sealing washer 10 is disposed between the upper face of the neck 3 and the flange 9, so as to be clamped between these elements during the crimping of the ring 5. The upper face of the neck 3 advantageously comprises a circular sealing rib 11, in particular with a triangular cross section which is anchored in the washer 10.

The pump 1 also comprises a push button 12 fitted with a dispensing nozzle 13 provided on the side wall of this button, the upper surface 14 of which serves as a bearing surface for the user. The button 12 is integral with a rod 15 slidingly mounted coaxially with the pump body 4 and sealingly passes through the central orifice of the washer 8, at least when the push-button 12 is in the high rest position illustrated on the figure 1.

The rod 15 comprises an axial longitudinal channel 16 opening, in the upper part, into a transverse conduit 17 of the push-button 12 communicating with the outlet orifice of the nozzle 13. At its lower part, the channel 16 stops before the the lower end of the rod 15 and communicates radially, for example by two diametrically opposite passages 18, with the lateral surface of the rod 15. The passages 18 are provided substantially at the mid-length of a cylindrical seat f of reduced diameter of the rod 15, this seat f being limited axially upwards by a shoulder 19 forming a stop and downwards by another shoulder 20, also forming stop.

A piston 21 is mounted around this bearing surface f of reduced diameter so as to be able to slide between a high position where the piston 21 is in abutment against the stop 19 and a low position where the piston 21 is in abutment against the shoulder 20.

The rod 15 comprises, above the piston 21, a flange 22 serving to support a precompression spring 23 which tends to apply the piston 21 against the lower shoulder 20.

The piston 21 divides the pump body 4 into two superimposed compartments, separated in a sealed manner by this piston 21. The upper compartment 24 will be called the air compartment, while the lower compartment 25 will be called the product compartment.

The lower part 26 of the compartment 25 and therefore of the pump body 4 has a frustoconical shape and ends in an axial nozzle 27 to which is connected a dip tube 28 extending to the bottom of the container 2.

A ball suction valve 29 is provided at the end of the lower part 26. The ball 29 is located inside a cylindrical cage 30 allowing the movement of the ball for opening the valve, but ensuring maintaining this ball in the vicinity of the seat provided on the internal surface of the part 26.

A return spring 31 is provided between the lower end of the rod 15, arranged in the form of a pin around which the upper end of the spring 31 is engaged, and the frustoconical part 26. The lower end of the spring 31 is engaged around the cylindrical cage 30.

The piston 21, combined with the passages 18 and the spring 23, constitutes a precompression valve.

The rod 15 is provided, on its outer surface, in the upper part, with a longitudinal groove 32 intended to allow entry of air, in compartment 24, when this groove, through its lower part, crosses the washer 8 as illustrated in FIG. 2.

The button 12 has a lower skirt 12 a which covers the cap 7, as illustrated in FIG. 2, at the end of depressing the push button 12.

However, the operation of the self-draining pump 1 is as follows.

It is assumed that the pump is primed and that in the rest position, illustrated in FIG. 1, of the product P is in the product compartment 25. In this rest position, the valve 29 is closed. The piston 21 is in the low position under the action of the precompression spring 23.

The assembly of the rod 15 and of the push-button 12 is in the high rest position, under the action of the spring 31. A dose of product P is located in the compartment 25.

To dispense the dose, the user, as illustrated in FIG. 2, exerts manual pressure on the push-button 12 so as to push it in and bring the rod 15 down into the pump body 4. The valve 29 remains in the closed position and the piston 21, descending with the rod 15, compresses the dose of product contained in the compartment 25.

When the pressure of the product, in this compartment 25 is sufficient to exert on the piston 21 a force greater than that of the spring 23, the piston 21 is pushed upwards up to the shoulder 19. The compartment 25 is then put in communication with the passages 18, the channel 16, the passage 17 and the nozzle 13, which allows the dose of product from the compartment 25 to exit through said nozzle. In addition, the movement of the piston 21 cut off all communication between the air compartment 24 and the passages 18.

When the groove 32, through its lower end, crosses the washer 8, air can enter the air compartment 24 during expansion.

During the ascent phase of the push button 12, as illustrated in FIG. 3, under the action of the return spring 31, then that the user no longer exerts pressure on the button 12, the pressure in the compartment 25 drops and becomes slightly negative which ensures the suction of the product P coming from the container 2. The piston 21 is pushed back by the spring 23 in the low position against the shoulder 20.

As soon as the lower end of the groove 32 crosses upwards the washer 8, the air compartment 24 is closed at the top and the rise of the piston 21 compresses the air from the container 24 and expels it through the passages 18 , the pipe 16, the passage 17 and the nozzle 13, thereby purging all these conduits of the remains of the product P which may remain after the previous distribution phase.

The purge or sweep operation which takes place during the ascent phase is particularly effective and is spread over part of this ascent phase.

The example described with reference to FIGS. 1 to 3 corresponds to a pump without air return in the container 2. If a pump with air return was to be used, an air return channel of the kind of that shown on Figures 4 to 6 would be provided between the washer 8 and the cap 7 to allow the entry of air into the container 2 as and when the product P.

Referring to Figures 4 to 6, we can see an alternative embodiment of a self-draining pump 101 provided in particular to facilitate priming.

The elements of this pump which are identical or playing roles analogous to elements already described in connection with FIGS. 1 to 3 are designated by numerical references equal to the sum of the number 100 and the numerical reference used previously. Their description will not be repeated or will be made only succinctly.

The pump body 104 has a narrowing 33 at its base provided in such a way that before the end of the sinking of the rod 115, the piston 121 abuts against this narrowing 33. Thus, the piston 121 is stopped while the rod 115 can continue to descend. The piston 121 therefore moves upward relative to the rod 115 by compressing the spring 123 and causing communication the radial passages 118 with the compartment 125. The piston 121, which comes into abutment against the upper shoulder 119 cuts the communication between the air compartment 124 and the passages 118 and 116.

Aside from this difference with respect to the embodiment of the previous figures, it can be noted, as another difference, that the rod 115, instead of having an air inlet groove similar to the groove 32 in the figures 1 to 3, has an upper part 115 a of smaller outer diameter than that of the lower part 115 b . The part 115 b slides in leaktight fashion in the central opening of the washer 108; on the other hand, when the part 115 a arrives at the height of the washer 108, as illustrated in FIG. 6, an air inlet in the compartment 124 is created.

The cap 107 is extended upwards by a tubular sleeve 34 coaxial with the pump body 104, the internal diameter of which is slightly greater than the external diameter of the part 115 b . This sleeve 34 ends, in the upper part, with a throttled part 35 against which the substantially frustoconical shoulder 36 comes into watertight support 36 between the parts 115 a and 115 b of the rod 115 in the high rest position of the push button 112. The throttled part 35 has a cylindrical end whose internal diameter is slightly greater than the external diameter of the part 115 a so that an air passage is possible between the part 115 a and the internal surface of the part 35 when the rod 115 is pressed in and the shoulder 36 is no longer pressing against the throttled part 35.

An air passage 37, constituted for example by a groove formed in the internal face of the cap 107 is provided for communicating the internal volume of the sleeve 34 with the internal volume of the container 102, bypassing the upper edge of the pump body 104 The passage 37 constitutes an air intake channel for the container 102. This channel 37 is eliminated in the case where it is desired that the pump 101 operates without air intake.

That said, the operation of the pump 101 is as follows.

It is assumed that the pump has not yet been used and that the compartment 125 (see FIG. 4) is empty of product, that is to say filled with air. To be able to prime the pump, it is necessary to eliminate the air present in this compartment 125.

The user, by pressing the push button 112, lowers the rod 115 in the pump body. The rod drives the piston 121 which remains in the low position, pressing against the shoulder 120, due to the action of the precompression spring 123. The air trapped in compartment 125 is compressed.

As illustrated in FIG. 6, during the descent of the rod 115, the piston 121 is stopped against the throttle 33. The rod 115 can continue to descend so that the piston 121 passes into the high position in abutment against the shoulder 119 which opens the passage 118 and allows the evacuation of the compressed air from the compartment 125 towards the atmosphere.

When the user stops pressing the push button 112, the rod 115 returns to the high position under the action of the return spring 131. The piston 121 returns to the low position under the action of the spring 123, and the rise of this piston, with the rod 115, creates a depression in the compartment 125. The ball 129 of the valve lifts and lets product P penetrate into the compartment 125 coming from the container 102. After three or four actuations of the push button 112 , compartment 125 is completely filled with the product to be dispensed. Pump 101 is primed.

When the user presses the push button 112 again, it causes the output of a dose of product as explained above. It will simply be recalled that initially, during the descent of the rod 115, the product contained in the compartment 125 is compressed until its pressure is sufficient to push the piston 121 against the action of the precompression spring 123, which corresponds substantially to the position shown in FIG. 5. The shoulder 36 of the rod 115 being spaced from the throttle 35, air can pass between the rod 115 and the internal surface of the sleeve 34 to reach the channel 37 and enter the container 102.

When the part 115 has a smaller diameter, the rod 115 reaches and exceeds, on descending, the washer 108, air can enter the air compartment 124.

During the ascent of the rod 115 under the action of the spring 131, the piston 121 returns to its low position and the product is sucked into the compartment 125. The air trapped in the compartment 124 is compressed and expelled through the passages 118 , the channel 116 and the nozzle 113 so as to purge these conduits of the remains of the product which has been dispensed.

The pump according to the invention can be used both for spraying a liquid and for dispensing a cream.

In the case of a liquid, the precompression spring 23, 123 will be chosen with a high stiffness in order to guarantee a good quality of spraying.

On the other hand, for a cream, or more generally for a paste, the precompression spring 123 will be practically nonexistent and will have a very low stiffness.

Whatever the embodiment, the self-draining pump according to the invention ensures an expulsion of air in the same pipes and the same outlet nozzle as the product. The residual product is thus expelled from the pump which avoids clogging, drying, contamination and other disadvantages of the same order.

Claims (11)

Pump for dispensing a product, liquid or pasty, through a dispensing nozzle, comprising a pump body intended to be mounted on a container containing the product to be dispensed and a push-button suitable for being pressed against elastic return means for causing the distribution of the product, said pump comprising a precompression valve suitable for authorizing the distribution of the product only when sufficient pressure is reached, air compression means being further provided for expelling air through the nozzle after dispensing the product, characterized in that the air compression means (21, 24; 121, 124) are arranged to expel the air, through the nozzle (13, 113 ), during the ascent phase of the push button (12, 112) under the action of elastic return means (31, 131) and that during the descent phase of the push button (12, 112) the above air compression means (24, 21) carry out an aspiration of air for its subsequent expulsion, while a dose of product (P) is distributed through the nozzle (13, 113). Pump according to claim 1, characterized in that the pressure relief valve (18, 21, 23,; 118, 121, 123) is arranged to cut the communication between the air compression means (21, 24; 121, 124) and the product outlet channel (16, 116) when said valve allows the product (P) to be dispensed through the outlet channel (16, 116). Pump according to claim 1 or 2, characterized in that the pump body (4, 104) comprises a cylindrical part in which a rod (15, 115) can move in longitudinal sliding linked to the push button and comprising a channel longitudinal (16, 116) opening, in the upper part, into a pipe (17, 117) leading to the nozzle (13, 113), this longitudinal channel (16, 116) communicating at its lower part by at least one radial passage ( 18, 118) with the lateral surface of the rod, the pressure relief valve comprising a piston (21, 121) slidably mounted around the rod (15, 115) at the radial passage (18, 118) between two stops (19 , 20; 119, 120), this piston (21, 121) sealingly separating the pump body in an air compartment (24, 124) located above the piston, and a product compartment (25, 125) located below the piston, the assembly being such that for a high position of the piston , the product compartment (25, 125) communicates with the aforesaid radial passage (18, 118) while for a low position of the piston the product compartment (25, 125) is separated from the radial passage while the air compartment ( 24, 124) is connected to this radial passage (18, 118). Pump according to claim 3, characterized in that the rod (15, 115) has a flange (22, 122) located above the piston (21, 121) and that a precompression spring (23, 123) is disposed between this flange and the piston, this spring (23, 123) having a tendency to push the piston (21, 121) in abutment against the lower stop (20, 120) and to keep the piston (21, 121) in the low position . Pump according to claim 3 or 4, characterized in that the elastic return means of the rod (15, 115) comprise a spring (31, 131) disposed between the lower part of the rod and the bottom (26, 126) of the pump body. Pump according to any one of claims 3 to 5, characterized in that the rod (15, 115) is slidably mounted, in the upper part, in a sealed manner in a cap (7, 107) closing the pump body, this rod comprising an upward air intake means (32, 115 a ) allowing air to enter the air compartment (24) while the push button rod is being pressed. Pump according to claim 6, characterized in that the air intake means comprises a longitudinal groove (32) formed on the upper part of the rod (15). Pump according to claim 6, characterized in that the air intake means comprises an upper part (115 a ), of the rod, of smaller diameter sliding in a kind of sleeve (34) extending upwards a cap (107) closing the pump body. Pump according to any one of the preceding claims, characterized in that an air return channel (37) is provided to allow air to enter the container (102) as it is evacuated of the product (P). Pump according to claim 3, characterized in that the lower part of the pump body has a throttle (33) arranged in such a way that at the end of the sinking of the rod (115), the piston (121) is stopped by this shoulder (33) while the rod (115) can continue its downward movement, which makes it possible to communicate the compartment (125) intended for the product, with the channel (116) for the evacuation of the air to favor priming of the pump. Product dispenser comprising a container (2, 102) in which the product is located, characterized in that the neck of this container is equipped with a pump according to any one of claims 1 to 10.

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