FR3139122A1 - Product distribution device comprising a helical bellows - Google Patents

Abstract

The present invention relates to a dispensing device (10) for liquid to pasty product comprising: - a pump body (12), - a push button (16) slidably mounted in the pump body (12), - a distribution conduit (18) arranged in the push button (16), - a dosing chamber (20), - an elastically deformable bellows (28), - an inlet valve (30), - an outlet valve ( 32), - an intermediate cavity (34), characterized in that the outlet valve (32) is mounted in a sliding manner axially on the push button (16) between a high position and a low position, so as to cause a suction effect sucking the product from the distribution conduit (18) towards the intermediate cavity (34) when sliding the push button (16) from a distribution position to an inactive position. Figure for abstract: Figure 2.

Description

Product distribution device comprising a helical bellows Technical field of the invention

The present invention relates to the field of devices for dispensing a liquid to pasty product to be dispensed, in particular a cream, an ointment or a paste, in particular for cosmetic use.

The invention relates more particularly to dispensing devices mounted on the neck of a container containing a liquid or a cream.

Technical background

It is known in the prior art, for example WO2019/102106A1, dispensing devices mounted on the neck of a container containing a liquid or a cream, comprising a pump motor with a dosing chamber, for example delimited by a bellow. An inlet valve and an outlet valve allow the inlet and outlet of this chamber to be opened or closed respectively.

When we activate the pump by pressing the push button, we generate a pressure inside the pump which on the one hand opens the outlet valve and allows the product to come out, and on the other hand, closes the valve. entry and prevents its flow back into the container. When the push button is released, the bellows forming an elastic return means, this bellows generates a return force on the push button, which then rises. By relaxing, the bellows generates a vacuum inside the pump. This depression causes on the one hand the opening of the inlet valve and the suction of the product contained in the container and its passage into the dosing chamber and on the other hand, closes the outlet valve and prevents the suction of air in the device.

To ensure proper operation of the dispensing device, it is not easy to find the optimal compromise between the rigidity and flexibility of the flexible elements forming the pump motor in order to guarantee ergonomic actuation by the user and precise distribution of the dose of product. In addition, after dispensing the dose of product, there generally remains a little product in the distribution conduit of the pump, between the dosing chamber and the exterior orifice. This remaining product can dry out between two uses of the pump and form a plug of dry product.

There is therefore a need to improve existing distribution systems.

The invention proposes a device for dispensing a liquid to pasty product comprising:
- a pump body designed to be mounted on a product tank,
- a push button mounted sliding in the pump body along a main axis between an inactive axial position and an axial distribution position,
- a distribution conduit arranged in the push button so as to allow the distribution of a dose of product,
- a dosing chamber of variable volume comprising a chamber inlet in communication with a supply conduit intended to be connected to the tank and a chamber outlet in communication with the distribution conduit,
- an elastically deformable bellows which laterally delimits the dosing chamber and which elastically biases the push button towards its inactive position,
- a first non-return valve, called an inlet valve, arranged so as to open or close the chamber inlet under the respective exercise of a reduction in pressure or an increase in pressure in the dosing chamber,
- a second non-return valve, called an outlet valve, arranged between the chamber outlet and the distribution conduit,
- an intermediate cavity arranged between the distribution conduit and the outlet valve so as to be able to store a determined quantity of product,
characterized in that the outlet valve is mounted in a sliding manner axially on the push button between a high position and a low position, so as to cause a suction effect sucking the product from the distribution conduit towards the intermediate cavity during the sliding of the push button from its dispensing position to its inactive position.

According to other characteristics of the invention:

- the outlet valve comprises a tubular body which is mounted sliding axially on an internal cylindrical portion of the push button;

- the tubular body comprises at least one abutment surface intended to cooperate with an associated support surface arranged on the internal cylindrical portion of the push button in order to define the low position;

- the tubular body and the internal cylindrical portion of the push button each comprise an undercut portion which respectively forms the abutment surface and the support surface;

- the tubular body of the outlet valve comprises a cylindrical portion at the upper end which is received axially in an annular slot delimited towards the inside by the internal cylindrical portion and towards the outside by a peripheral cylindrical wall of the push button;

- the outlet valve comprises a peripheral lip which extends from the external wall of the tubular body and which bears against an associated surface of the bellows in the closed position;

- the bellows comprises at least one internal shoulder portion, on the side of its upper axial end, and the peripheral lip rests at least partly on said internal shoulder portion when the push button occupies a locked angular position;

- the bellows comprises an upper flange intended to come into axial support against an upper rim formed in the push button and an upper tubular extension which includes a window capable of being aligned radially with the distribution conduit, in an unlocked angular position of the button -push button, and capable of being offset radially relative to the distribution conduit, in a locked angular position of the push button, so that the upper tubular extension closes the distribution conduit on the interior side in the locked position;

- the upper end wall of the push button is inclined along a downward slope towards the side opposite the distribution conduit, and the upper tubular extension has a beveled shape at its upper free end so that the highest part of the upper tubular extension is generally aligned radially with the distribution conduit when the push button occupies its locked position;

- the bellows comprises, in the vicinity of its lower end, a lower flange intended to come into axial support against a lower rim formed in the pump body, and a lower tubular extension which is mounted tight in an annular housing formed in the body of the pump pump ;

- each flange comprises at least one coding element which is designed to cooperate with a complementary coding element formed in the pump body, so as to only allow one angular mounting position of the bellows in the pump body;

- the coding elements of the flanges are each made up of two opposite notches and the notches of the upper flange are aligned radially with the notches of the lower flange;

- the pump body comprises two partially cylindrical axial tongues whose circumferential dimension is substantially equal to the circumferential dimension of each notch formed in the lower flange, so as to prevent pivoting around the main axis of the lower flange;

- the bellows is formed of beads in the form of helical turns.

Brief description of the figures

Other characteristics and advantages of the invention will appear during reading of the detailed description which follows, for the understanding of which we will refer to the appended drawings in which:

is an exploded perspective view which schematically represents a distribution device conforming to the teachings of the invention and an associated reservoir;

is a sectional view along plan 2-2 which schematically represents the distribution device of the when the push button is in a locked and inactive position;

is a sectional view according to plan 3-3 which schematically represents the distribution device of the when the push button is in an unlocked and inactive position;

is a view similar to that of the which schematically represents the distribution device of the when the push-button occupies an intermediate actuation position after an axial movement of the push-button by an axial movement corresponding to the relative movement of the outlet valve relative to the push-button from a low stop position to a high position of stop, the product has not started to fill the distribution conduit;

is a view similar to that of the which schematically represents the distribution device of the when the push button occupies its lower position in which the bellows which equips it is compressed and the product has been expelled from the dosing chamber by the distribution conduit;

is a view similar to that of the which schematically represents the distribution device of the at the start of the return to the inactive position, the push button having moved a distance corresponding to the axial movement allowing the outlet valve, which does not move at this stage, to return to its lower stop position by causing suction of the product contained in the distribution conduit towards an intermediate cavity;

is a view similar to that of the which schematically represents the distribution device of the at the end of the push-button's rise to its inactive high position;

is a view is a view similar to that of the which illustrates the locking of the distribution device of the ;

is a side view and is a top view which represents the bellows equipping the distribution device of the before assembly;

is a view similar to that of the And is a view similar to that of the which represent the bellows in a slightly compressed state corresponding to its mounted state in the distribution device before actuation of the push button;

is a view similar to that of the And is a view similar to that of the which represent the bellows in a compressed state corresponding to the lower position of the push button;

is a view similar to that of the which represents a variant embodiment of the distribution device in which the tank includes a non-return valve which allows it to be released to the open air.

Detailed description of the invention

In the description which follows, identical, similar or analogous elements will be designated by the same reference numerals.

Figures 1 and 2 represent a dispensing device 10 for liquid to pasty product, or pump, in accordance with the teachings of the invention. The dispensing device 10 comprises a pump body 12 which is designed to be mounted on a product reservoir 14, for example by screwing.

The dispensing device 10 comprises a push button 16 slidably mounted in the pump body 12, along a main axis A1, between an inactive axial position, which is illustrated by the and an axial distribution position, which is illustrated by the .

On the , there is shown a protective cover 13 which is intended to be mounted on the tank 14 so as to protect the push button 16 and a product distribution orifice.

Note that Figures 2 to 8 illustrate several axial and angular operating positions which will be explained subsequently.

In the remainder of the description, without limitation, elements will be designated as higher or lower by conventionally considering a vertical orientation along the main axis A1.

A distribution conduit 18 is arranged in the push button 16 so as to allow the distribution of a dose of product coming from a dosing chamber 20 with variable volume.

The dosing chamber 20 is inserted between the distribution conduit 18 located downstream of the product distribution circuit, and the reservoir 14 located upstream of the product distribution circuit.

The dosing chamber 20 comprises a chamber inlet 22 in communication with a supply conduit 24 intended to be connected to the reservoir 14 and a chamber outlet 26 in communication with the distribution conduit 18.

The supply conduit 24 is here formed of a tube which is made in one piece by molding with the pump body 12, along the main axis A1, and which plunges inside the reservoir 14 to allow be able to take the product to be distributed.

The dispensing device 10 also includes an elastically deformable bellows 28 which laterally delimits the dosing chamber 20 and which elastically biases the push button 16 towards its inactive position, here upwards. The bellows 28 is preferably made in one piece by molding from elastomeric material.

A first non-return valve, called inlet valve 30, is arranged so as to open or close the chamber inlet 22 under the exercise respectively of a reduction in pressure or an increase in pressure in the chamber. dosage 20.

A second non-return valve, called outlet valve 32, is arranged between the chamber outlet 26 and the distribution conduit 18, so as to open the chamber outlet 26 when dispensing a dose of product and to close the exit from chamber 26 at the end of this distribution.

An intermediate cavity 34 is arranged between the distribution conduit 18 and the outlet valve 32 so as to be able to store a certain quantity of product.

Advantageously, the outlet valve 32 is mounted in a sliding manner axially on the push button 16 between a high position, which is illustrated in particular on the , and a low position, which is illustrated in particular on the . The sliding of the outlet valve 32 makes it possible to cause a suction effect drawing the product from the distribution conduit 187 towards the intermediate cavity 34 during the sliding of the push button 16 from its distribution position to its inactive position.

According to the embodiment shown here, the outlet valve 32 comprises a tubular body 36 which is slidably mounted axially on an internal cylindrical portion 38 of the push button 16. The tubular body 36 comprises a first abutment surface 40 which is provided for cooperate with a first associated support surface 42 arranged on the internal cylindrical portion 38 of the push button 16 in order to define the low position, and a second abutment surface 41 which is provided to cooperate with a second associated support surface 43 arranged on the internal cylindrical portion 38 in order to define the high position.

The tubular body 36 and the internal cylindrical portion 38 of the push button 16 each include an undercut portion which respectively forms the first abutment surface 40 and the first bearing surface 42.

The abutment surfaces 40, 41 and the bearing surfaces 42, 43 delimit an axial movement d1 of the outlet valve 32 relative to the push button 16, the function of which will be described subsequently.

The tubular body 36 of the outlet valve 32 here comprises a cylindrical upper end portion 44 which is received axially in an annular slot 46 delimited towards the inside by the internal cylindrical portion 38 and towards the outside by a peripheral cylindrical wall 48 of push button 16.

Note that the intermediate cavity 34 here has an annular shape since it extends all around the tubular body 36 of the outlet valve 32 and around the peripheral cylindrical wall 48 of the push button 16.

According to the embodiment shown, the outlet valve 32 comprises a peripheral lip 50 which extends from the external wall of the tubular body 36 and which bears against an associated surface of the bellows 28 in the closed position. Peripheral lip 50 is mounted here curved upwards, inside the bellows. It is designed to be elastically supported against the bellows 28 so as to be able to be erased by elastic deformation when it comes to allowing the product to be distributed to pass towards the intermediate cavity 34 and the distribution conduit 18, and so to sealably close the dosing chamber 20 in other cases.

Preferably, the push button 16 is pivotally mounted around the main axis A1, relative to the pump body 12, between a locked angular position, which is illustrated by the , and an unlocked angular position, which is illustrated by Figures 3 to 7.

In the locked angular position, the passage between the intermediate cavity 34 and the distribution conduit 18 is closed to avoid any contamination of the product contained in the intermediate cavity 34 by contaminants contained in the outside air, to limit interactions with the environment exterior (anti-drying, dust, etc.). In addition, the push button 16 is blocked in axial sliding which prevents any unwanted manipulation. To obtain this blocking, suitable blocking members (not shown) can be arranged in the pump body 12 and in the push button 16, these blocking members being retracted into the unlocked angular position.

In the unlocked angular position, the passage between the intermediate cavity 34 and the distribution conduit 18 is open to allow the distribution of a dose of product, and the push button 16 is free to slide axially.

Advantageously, the bellows 28 comprises at least one internal shoulder portion 52, on the side of its upper axial end 54. The peripheral lip 50 is provided to rest at least in part on the internal shoulder portion 52 when the push button 16 occupies its locked angular position.

The bellows 28 is shown in more detail in Figures 9 to 14 in several positions. Figures 9 and 12 represent the bellows 28 before mounting in the distribution device 10. Figures 10 and 13 represent the bellows 28 in a slightly axially compressed state, when it is mounted in the distribution device 10 and the latter occupies its unlocked angular position, before actuation of the distribution device 10, as illustrated by the . Figures 11 and 14 represent the bellows 28 in an axially compressed state corresponding to the lower position of the push button 16, as illustrated by the .

According to the embodiment shown, the bellows 28 comprises an upper flange 56 intended to come into axial support against an upper rim 58 formed in the push button 16 and an upper tubular extension 60 which includes a window 62 capable of being aligned radially with the distribution conduit 18, in the unlocked angular position of the push button 16. The window 62 thus forms a passage for the product to be distributed between the distribution conduit 18 and the intermediate cavity 34. In the locked angular position of the push button 16, the window 62 is offset radially with respect to the distribution conduit 18, so that the upper tubular extension 60 closes the distribution conduit 18 on the interior side.

According to the embodiment shown, the upper end wall 64 of the push button 16 is inclined along a downward slope towards the side opposite the distribution conduit 18. The upper tubular extension 60 of the bellows 28 has a beveled shape at its upper free end so that the uppermost part of the upper tubular extension 60 is generally aligned radially with the distribution conduit 18 when the push button 16 occupies its locked position. The height of the beveled shape is adjusted relative to the upper end wall 64 of the push button 16 so that the angular pivoting of the push button 16 is not hampered by mechanical interference between the bellows 28 and the button. pusher 16.

Preferably, the bellows 28 comprises, near its lower end, a lower flange 66 designed to come into axial support against a lower rim 68 formed in the pump body 12. The bellows 28 also includes a lower tubular extension 70 which is mounted tightly in an annular housing 72 formed in the pump body 12.

Advantageously, each flange 56, 66 comprises at least one coding element which is designed to cooperate with a complementary coding element formed in the pump body 12, so as to only allow one angular mounting position of the bellows 28 in the pump body 28.

According to the embodiment shown, the keying elements of the flanges 56, 66 are each constituted by two opposite notches 74, 76. The notches 74 of the upper flange 56 are aligned radially with the notches 76 of the lower flange 66. The pump body 12 here comprises two axial tongues 78, in the form of a cylindrical wall, which extend axially upwards from the base of the pump body 12. These axial tongues 78 contribute here to the axial guidance of the push button 16, a main axial wall 80 of the push button 16 being received in the radial space located between an axial wall of the pump body 12 and the main axial wall 80 of the push button 16.

The circumferential dimension of each axial tongue 78 is here substantially equal to the circumferential dimension of each notch 76 formed in the lower flange 66, so as to prevent pivoting around the main axis A1 of the lower flange 66.

Preferably, the bellows 28 is formed of beads 82 in the form of helical turns, which in particular allows greater ease of manufacturing by molding because such a shape is easier to unmold.

Due to its helical shape, the axial compression of the bellows 28 during assembly in the distribution device 10 tends to cause a first relative angular pivoting a1 of the upper flange 56 relative to the lower flange 66. Then the axial compression of the bellows 28 when the push button 16 is actuated tends to cause a second relative angular pivoting a2 of the upper flange 56 relative to the lower flange 66.

The lower axial end of the bellows 28 being blocked in pivoting thanks to its tight mounting in the annular housing 72, only the upper tubular extension 60 and the upper flange 56 of the bellows 28 pivot.

Advantageously, the direction of rotation of the helical shape of the bellows 28 is opposite to the locking direction of the push-button 16, in order to prevent the pivoting of the upper flange 56 during compression of the bellows 28 from stressing the button- pusher 16 in the locking direction when the latter is raised.

Advantageously, to take into account the pivoting of the upper flange 56 during compression of the bellows 28, the window 62 extends over a circumferential distance greater than the circumferential dimension of the distribution conduit 18. According to the embodiment shown, the window 62 has an oblong shape which extends circumferentially in the wall of the upper tubular extension 60.

The position of the distribution conduit 18 relative to the upper tubular extension 60 and the window 62, in an unlocked position of the push button 16, is illustrated by Figures 10 and 11. It can be seen that in the inactive position of the , the distribution conduit 18 is offset towards a first circumferential end 81 of the window 62 and, in the low position of the , the distribution conduit 18 is offset towards a second circumferential end 83 of the window 62.

Note that the inlet valve 30 is preferably made in one piece of elastomeric material. It comprises an elastically deformable flexible membrane, here in the shape of a disc, to allow the product to pass towards the dosing chamber 20 when the latter is in depression, and to close the chamber inlet 22 during the distribution of the product or in the inactive position of the distribution device 10. The inlet valve 30 comprises a central body 84 which allows it to be mounted by force in a suitable housing of the pump body 12.

An example of such an inlet valve 30 is described and represented for example in document WO2018/162850A1.

The distribution device 10 described and shown in the figures is here of the type without air intake, or “airless” according to English terminology. This is why the tank 14 here has a sliding bottom wall 86 which makes it possible to adjust the volume of the tank 14 to the volume of product remaining in the tank 14.

According to an alternative embodiment, which is represented schematically on the , the distribution device 10 applies to a device of the type with venting, that is to say comprising an orifice for bringing to atmospheric pressure 90. In this case, the orifice for releasing atmospheric pressure 90 can be arranged in the bottom wall of the pump body 12 and provided with a non-return vent valve 92 of the same type as the inlet valve 30, mounted in the opposite direction to allow a regulated air inlet into the tank 14 in order to replace the product distributed with air.

According to the embodiment shown in the figures, the tubular body 36 of the outlet valve 32 extends downwards, inside the dosing chamber 20, by a closed portion 88. This closed portion 88 allows the valve to outlet 32 to cover the internal cylindrical portion 38 of the push button 16 by reducing the volume of the dosing chamber 20.

We now describe the operation of the distribution device 10 according to the invention by considering the different operating stages illustrated in Figures 2 to 8.

There illustrates the distribution device 10 in the mechanically and hydraulically locked position. In fact, the push button 16 occupies its locked angular position in which the passage between the distribution conduit 18 and the intermediate cavity 34 is closed by the upper tubular extension 60 of the bellows 28, which prevents any circulation of the product towards the 'outside. In addition, a mechanical blocking member (not shown) blocks any axial sliding of the push button 16 downwards. For example, the lower axial ends of the main axial wall 80 of the push button 16 are located opposite an associated abutment surface formed in the pump body 12.

Note that the dispensing device 10 has been described here in an already initiated configuration, that is to say that the product has already been distributed, the product filling the dosing chamber 20 and the intermediate cavity 34.

From the position shown on the , to be able to start dispensing a product, a user must rotate the push button 16 around its axis A1 to its unlocked angular position illustrated by the . This pivoting makes it possible to bring the window 62 opposite the distribution orifice 18 to allow the expulsion of the product towards the outside.

From the unlocked angular position illustrated by the , the user exerts axial downward pressure on the push button 16. This axial support causes a reduction in the volume of the dosing chamber 20 and an expulsion of product through the chamber outlet 26, thanks to the elastic deformation of the outlet valve 32. During this phase, the pressure increases in the dosing chamber 20 which prevents the opening of the inlet valve 30.

There illustrates the start of the distribution of the product, after a slight axial movement of the push button 16, the product first filling the distribution conduit 18. At the start of this downward axial movement, the outlet valve 32 slides axially d a distance corresponding to its axial movement d1 along the internal cylindrical portion 38 of the push button 16. Throughout the duration of the distribution of the product, the outlet valve 32 maintains its upper stop position.

There illustrates the end of the distribution of the product, while the push button 16 has reached a lower axial stop position and practically emptied the dosing chamber 20. In this axial position, the outlet valve 32 is still in its stop position upper axial relative to the internal cylindrical portion 38 of the push button 16.

There illustrates the start of the rise of the push-button 16. In this ascending phase, under the effect of the elastic return exerted by the bellows 28 upwards, over an axial distance substantially equal to the axial movement d1, the outlet valve 32 begins by returning to its lower axial stop position, as on the . A depression is generated inside the bellows 28 which has the effect of moving the outlet valve 32 downwards. The relative movement of the outlet valve 32 relative to the push button 16 causes a suction phenomenon in the cavity intermediate 34 since the volume thereof increases slightly thanks to the relative movement of the outlet valve 32. This suction phenomenon is used to empty the distribution conduit 18, the product which was contained in this distribution conduit 18 coming fill the volume available in the intermediate cavity 34.

Note that the value of the axial clearance d1 is chosen as a function of the volume of the distribution conduit 18, so as to be sufficient to ensure complete emptying of the distribution conduit 18.

There illustrates an intermediate step during the raising of the push button 16, showing the opening of the inlet valve 30, thanks to the depression caused in the dosing chamber 20, and the progressive filling of the dosing chamber 20 by the product coming from tank 14.

There illustrates the return to a locked angular position of the push button 16, which makes it possible in particular to close the intermediate cavity 34 by means of the upper tubular extension 60 of the bellows 28, and which makes it possible to isolate the product contained in the cavity intermediate 34 of the outside air.

Note that the hydraulic locking obtained in the locked angular position also makes it possible to prevent the product from coming out in the event of depression outside the distribution device 10, for example in the event of plane travel.

Even in the unlocked position illustrated by the , where the passage is open towards the intermediate cavity 34, the product contained in the intermediate cavity 34 is better protected than when it fills the distribution conduit 18. In fact, the surface of product in contact with the air is reduced and distant from the external end of the distribution conduit 18. In addition, the quantity of product in the volume of the intermediate cavity 34 makes it possible to slow down the drying of the product.

LEGEND

10: distribution device
12: pump body
13: protective cover
14: tank
16: push button
18: distribution conduit
20: dosing chamber
22: bedroom entrance
24: supply conduit
26: exit from room
28: bellows
30: inlet valve
32: outlet valve
34: intermediate cavity
36: tubular body
38: internal cylindrical portion
40, 41: abutment surfaces
42, 43: support surfaces
44: cylindrical upper end portion
46: annular slot
48: peripheral cylindrical wall
50: peripheral lip
52: internal shoulder portion
54: upper axial end
56: upper flange
58: upper edge
60: upper tubular extension
62: window
64: upper end wall
66: lower flange
68: lower edge
70: lower tubular extension
72: annular housing
74, 76: notches
78: axial tab
80: main axial wall
81: first circumferential end
82: bead
83: second circumferential end
84: central body
86: back wall
88: closed portion
90: atmospheric pressure port
92: non-return ventilation valve
A1: main axis
a1: first angular pivot
a2: second angular pivot
d1: axial travel

Claims (14)

Dispensing device (10) for liquid to pasty product comprising:
- a pump body (12) intended to be mounted on a product reservoir (14),
- a push button (16) mounted sliding in the pump body (12) along a main axis (A1) between an inactive axial position and an axial distribution position,
- a distribution conduit (18) arranged in the push button (16) so as to allow the distribution of a dose of product,
- a dosing chamber (20) of variable volume comprising a chamber inlet (22) in communication with a supply conduit (24) intended to be connected to the reservoir (14) and a chamber outlet (26) in communication with the distribution conduit (18),
- an elastically deformable bellows (28) which laterally delimits the dosing chamber (20) and which elastically biases the push button (16) towards its inactive position,
- a first non-return valve, called inlet valve (30), arranged so as to open or close the chamber inlet (22) under the exercise respectively of a reduction in pressure or an increase in pressure in the dosing chamber (20),
- a second non-return valve, called outlet valve (32), arranged between the chamber outlet (26) and the distribution conduit (18),
- an intermediate cavity (34) arranged between the distribution conduit (18) and the outlet valve (32) so as to be able to store a determined quantity of product,
characterized in that the outlet valve (32) is mounted in a sliding manner axially on the push button (16) between a high position and a low position, so as to cause a suction effect sucking the product from the distribution conduit (18) towards the intermediate cavity (34) when sliding the push button (16) from its distribution position to its inactive position. Dispensing device (10) according to the preceding claim, characterized in that the outlet valve (32) comprises a tubular body (36) which is slidably mounted axially on an internal cylindrical portion (38) of the push button (16). Dispensing device (10) according to the preceding claim, characterized in that the tubular body (36) comprises at least one abutment surface (40, 41) designed to cooperate with an associated bearing surface (42, 43) arranged on the internal cylindrical portion (38) of the push button (16) in order to define the low position. Dispensing device (10) according to the preceding claim, characterized in that the tubular body (36) and the internal cylindrical portion (38) of the push button (16) each comprise an undercut portion which respectively forms the surface of stop (40) and the support surface (42). Distribution device (10) according to any one of claims 2 to 4, characterized in that the tubular body (36) of the outlet valve (32) comprises a cylindrical upper end portion (44) which is received axially in an annular slot (46) delimited towards the inside by the internal cylindrical portion (38) and towards the outside by a peripheral cylindrical wall (48) of the push button (16). Dispensing device (10) according to any one of claims 2 to 5, characterized in that the outlet valve (32) comprises a peripheral lip (50) which extends from the external wall of the tubular body (36) and which bears against an associated surface of the bellows (28) in the closed position. Distribution device (10) according to the preceding claim, characterized in that the bellows (28) comprises at least one internal shoulder portion (52), on the side of its upper axial end, and in that the peripheral lip (50) ) rests at least partly on said internal shoulder portion (52) when the push button (16) occupies a locked angular position. Dispensing device (10) according to any one of the preceding claims, characterized in that the bellows (28) comprises an upper flange (56) intended to come into axial support against an upper rim (58) formed in the push button (16) and an upper tubular extension (60) which comprises a window (62) capable of being radially aligned with the distribution conduit (18), in an unlocked angular position of the push button (16), and capable of being offset radially relative to the distribution conduit (18), in a locked angular position of the push button (16), so that the upper tubular extension (60) closes the distribution conduit (18) on the interior side in the locked position . Dispensing device (10) according to the preceding claim, characterized in that the upper end wall (64) of the push button (16) is inclined along a downward slope towards the side opposite the distribution conduit (18), and in that the upper tubular extension (60) has a beveled shape at its upper free end so that the uppermost part of the upper tubular extension (60) is generally aligned radially with the distribution conduit (18) when the push button (16) is in its locked position. Dispensing device (10) according to any one of the preceding claims, characterized in that the bellows (28) comprises, near its lower end, a lower flange (66) designed to come into axial support against a lower rim ( 68) formed in the pump body (12), and a lower tubular extension (70) which is tightly mounted in an annular housing formed (72) in the pump body (12). Distribution device (10) according to the preceding claim taken in combination with claim 8, characterized in that each flange (56, 66) comprises at least one polarizing element which is intended to cooperate with a complementary polarizing element formed in the pump body (12), so as to allow only one angular mounting position of the bellows (28) in the pump body (12). Dispensing device (10) according to the preceding claim, characterized in that the keying elements of the flanges (56, 66) each consist of two opposite notches (74, 76) and in that the notches (74) of the flange upper (56) are aligned radially with the notches (76) of the lower flange (66). Dispensing device (10) according to the preceding claim, characterized in that the pump body (12) comprises two partially cylindrical axial tongues (78) whose circumferential dimension is substantially equal to the circumferential dimension of each notch (76) formed in the lower flange (66), so as to prevent pivoting around the main axis (A1) of the lower flange (66). Distribution device (10) according to any one of the preceding claims, characterized in that the bellows (28) is formed of beads in the form of helical turns.