Pump

Abstract

The invention relates to a pump comprising a fluid product chamber (Cp), an actuating lever (T) equipped with a pushing member (P) actuatable by a user, and a return device (Cd) for returning the actuating lever (T) to an idle position, characterized in that the return device comprises a vacuum chamber (Cd) in which the actuating lever (T) is provided with a pushing member (P) actuatable by the user, the invention relates to a vacuum valve having a volume that can be varied between a minimum volume state and a maximum volume state by moving an actuating lever (T), the minimum volume state being obtained when the actuating lever (T) is in a stop position, and the maximum volume state being obtained when the actuating lever (T) is in a depressed position, where the maximum volume state corresponds to a maximum vacuum, the minimum volume state corresponds to a minimum vacuum, and the actuating lever (T) is biased to its stop position by a vacuum present in the vacuum chamber (Cd).

Description

[0001] The invention relates to a pump comprising a fluid product chamber with a variable volume and an actuating pin which is axially movable between a non-operating position and a depressed position, in such a way that the volume of the chamber varies between a maximum volume state and a minimum volume state, respectively. The pump comprises a return means for returning the actuating pin to a non-operating position corresponding to the maximum volume state of the fluid product chamber. The actuating pin is equipped with an actuator which can be actuated by a user. Advantageous fields of application of the invention are those of pharmacy, cosmetics and fragrances, but other fields are not excluded.

[0002] Conventionally, the return means are in the form of springs, usually made of metal. The problem with these metal springs is that they hinder or complicate the recycling of the pump, all the more so because they are arranged in the pump body. There are plastic springs that are easier to recycle, but they tend to lose their stiffness over time.

[0003] The present invention seeks to overcome the disadvantages of these prior art springs by proposing another type of elastic return device which does not present the problems concerning recovery or stiffness.

[0004] To this end, the present invention proposes that the return device includes a partial vacuum chamber, whose volume changes between a minimum volume state and a maximum volume state through the movement of an actuating pin, the minimum volume state of the partial vacuum chamber is reached in the non-working position of the actuating pin, and the maximum volume state of the partial vacuum chamber is reached in the depressed position of the actuating pin, the maximum volume state of the partial vacuum chamber corresponds to the maximum partial vacuum, and the minimum volume state of the partial vacuum chamber corresponds to the minimum partial vacuum, and the actuating pin is pushed to its non-working position by the partial vacuum existing in the partial vacuum chamber.

[0005] Therefore, the partial vacuum chamber creates a partial vacuum from the point where the pressure in the partial vacuum chamber approaches or equals atmospheric pressure. Therefore, the pressure in the partial vacuum chamber is always less than or equal to atmospheric pressure. As the actuating pin moves from its inoperative position to its depressed position, the partial vacuum increases. It is a type of reverse air pump.

[0006] According to the invention, the pump further comprises mechanical means, which are independent of the partial vacuum in the partial vacuum chamber and which can be actuated by the user in order to return and maintain the partial vacuum chamber in its minimum volume state. Thus, starting from the maximum volume state (maximum partial vacuum), the volume of the partial vacuum chamber decreases as soon as the user releases the pressure on the actuator. This volume reduction continues under the effect of the partial vacuum until the mechanical means are engaged. Thus, the user can actuate these mechanical means in order to further reduce the volume of the partial vacuum chamber, ultimately reaching its minimum volume state. During the entire process for actuating the mechanical means, the partial vacuum in the minimum volume state does not need to be present. The partial vacuum is sufficient to trigger the mechanical means.

[0007] Advantageously, the mechanical device is controlled by an actuator via an actuating pin. In other words, the user grasps the actuator which has the effect of actuating the mechanical device and moves it. The movement of the actuator may be rotational, axial, or both rotational and axial. According to the invention, the mechanical device comprises a threaded connection which makes it possible to move the actuator and the actuating pin axially and rotationally. Advantageously, the threaded connection may define an axial stroke which is bounded on one side by a top stop corresponding to the minimum volume state of the partial vacuum chamber and on the other side by the release of the threaded connection, thereby allowing a subsequent change of the volume of the partial vacuum chamber towards its maximum volume state. From an ergonomic and gesture point of view, the user will grasp the actuator to rotate it through a specific angle, such as a quarter turn or a half turn, in order to selectively turn it into a locked or unlocked position. This locking / unlocking system by rotating the actuator is conventional. In the context of the invention, the actuation of the locking / unlocking system also simultaneously causes the actuation of the mechanical device without the user even noticing it.

[0008] Due to the mechanism, the partial vacuum chamber always returns to the same starting point of minimum volume.

[0009] According to another advantageous feature of the invention, which can be advantageously combined with a mechanical device, the partial vacuum chamber is connected to the outside in its minimum volume state. Therefore, even if the partial vacuum chamber leaks and allows air to enter, this air will be evacuated to the outside so that the partial vacuum chamber always starts at the same pressure close to atmospheric pressure. This initial or final leakage can be achieved independently of the mechanical device, but the partial vacuum in the partial vacuum chamber must be sufficient to bring the partial vacuum chamber to or close to its minimum volume state. This is possible, but difficult to achieve in practice, especially in a repeatable manner. This is why it is particularly advantageous to combine this initial or final leakage with a mechanical device, which ensures that the partial vacuum chamber always returns to its minimum volume state. It can then be said that the mechanical device supplements or completes the partial vacuum so as to ensure that the partial vacuum chamber is reset in each actuation cycle by connecting the partial vacuum chamber to the outside.

[0010] According to one embodiment of the invention, the actuating pin comprises a partial vacuum chamber piston that slides axially in a sealed manner in the barrel of the partial vacuum chamber, in such a way that the partial vacuum chamber is defined between them, the actuating pin forming an exhaust groove that connects the partial vacuum chamber with the outside in a non-operating state of the actuating pin corresponding to a state of minimum volume of the partial vacuum chamber. When the pump is not running, the groove, recess or channel establishes an air connection between the partial vacuum chamber and the outside, and this connection is cut off as soon as the actuating pin leaves its non-operating state or shortly after leaving its non-operating state, in such a way that the partial vacuum chamber is isolated. A travel of a few tenths of a millimeter is sufficient to isolate the partial vacuum chamber.

[0011] According to another aspect of the present invention, the actuating pin may include a piston member and a valve shutter, wherein the piston member forms a partial vacuum chamber piston that slides in the barrel of the partial vacuum chamber, the piston member also forms a fluid product chamber piston that slides in the barrel of the fluid product chamber, the piston member advantageously forms a movable outlet valve member of the fluid product chamber, and the valve shutter advantageously forms an outlet valve seat of the fluid product chamber. Advantageously, the piston member can be axially movable relative to the valve shutter under the pressure existing in the fluid product chamber, but is driven to rotate by the valve shutter. Advantageously, the threaded connector is located between the piston member and the barrel of the partial vacuum chamber. The piston member can be referred to as a differential piston because it moves under the pressure existing in the fluid product chamber. Instead of the piston member, an actuating pin equipped with a fixed partial vacuum chamber piston and a fluid product chamber piston can be provided, and the fluid product chamber piston slides on the actuating pin under the pressure existing in the fluid product chamber.

[0012] According to another approach of the invention, the partial vacuum chamber may be said to define a maximum axial travel between its minimum volume state and its maximum volume state, which is broken down into:

[0013] - a main stroke starting from a maximum volume state caused by the partial vacuum existing in the partial vacuum chamber, and

[0014] - a secondary stroke to a maximum volume state, brought about by driving the actuator rotationally and / or axially, said secondary stroke terminating in an axial locking position of the actuator.

[0015] A user who grasps a dispenser on which the pump of the present invention is mounted will quickly discern that the actuator is in a locked position by pressing the top or by noting the visible instructions on the actuator. Thus, the user will drive the actuator to rotate through a specific angle in order to unlock it. In doing so, but not obviously, the user has actuated a mechanism that has converted the partial vacuum chamber from its minimum volume state in communication with the outside to an intermediate state isolated from the outside. In the case where the mechanism adopts a threaded connector, the intermediate position corresponds to the end of the threaded connector, where the actuating pin is released from the threaded connector. The user then presses the actuator axially, which has the effect of dispensing the fluid product and generating an increased partial vacuum in the partial vacuum chamber at the same time. Once the dispensing of the fluid product is complete, the user releases the axial pressure on the actuator so that the partial vacuum in the partial vacuum chamber has the effect of returning the actuating pin and its actuator toward the non-operating position. However, the return stroke of the rod stops at the intermediate position, which corresponds to the activation of the mechanism. In the case where the mechanism adopts a threaded connector, the partial vacuum raises the actuating pin until the thread engages. It is then sufficient for the user to turn the actuator to lock it, which simultaneously has the effect of returning the actuating pin to the inoperative position and returning the partial vacuum chamber to its minimum volume state in which it communicates with the outside through the exhaust groove of the actuating pin. The locked position corresponds to the stop of the threaded connection.

[0016] The spirit of the invention lies in the threaded connection that allows the air spring to return to its starting point. Furthermore, in order to mitigate the risk of leakage, it is vented at its starting point. The threaded connection combined with the leakage at the starting point provides a synergistic effect that makes its operation fully repeatable and therefore reliable. Thus, the air spring is reset after each actuation.

[0017] The invention will now be described in more detail with reference to the accompanying drawings which are given by way of non-limiting examples of embodiments of the invention.

[0018] In the attached picture:

[0019] Figure 1 is a vertical cross-sectional view through a fluid product dispenser according to the present invention, the fluid product dispenser being in a locked and non-operating state;

[0020] Figure 2a yes Figure 1 A magnified view of the pump in a locked and non-operating state;

[0021] Figure 2b is with Figure 2a A similar view with the pump in the unlocked position;

[0022] Figure 3a yes Figure 2a A greatly enlarged view of a portion of

[0023] Figure 3b yes Figure 2b A greatly enlarged view of a portion of

[0024] Figure 4a , 4b and 4c represent a valve gate of a pump according to the present invention,

[0025] Figure 5a , 5b , 5c and 5d represent piston members of a pump according to the present invention, and

[0026] Figure 6a , 6b and 6c represent a pump body according to the present invention.

[0027] Figure 1 The pump of the invention is shown mounted on a fluid product reservoir R, which is not critical to the invention. In fact, this reservoir R can be of any type, of any shape and can be made of any suitable material. It is sufficient for the reservoir to form an opening, for example in the form of a neck, on which the pump of the invention can be mounted in a secure and sealed manner.

[0028] The pump of the invention comprises firstly a pump body 3 which receives the fixing elements 4, 5 and 6 and the movable element, namely the actuating pin T. The pump body 3 forms a ring 35 intended to cooperate with the neck of the reservoir R for fixing the pump to the reservoir. Below this fixing ring 35, the pump body 3 forms a fitting bushing 36 in which the bottom part 6 equipped with a soaking tube 61, the cylindrical part 5 equipped with an inlet valve 51 and the sleeve 4 for sealingly guiding the actuating pin T are firmly mounted. The cylindrical part 5 is retained between the bottom part 6 and the sleeve 4. The bottom part 6 can be permanently snap-connected in the opening formed by the bushing 36 of the pump body 3. The design of these fixing parts 4, 5 and 6 is not critical to the invention and other architectures can therefore be envisaged without departing from the scope of the invention.

[0029] The actuating pin T is slidably mounted in the pump body 3 along the longitudinal axis X. A portion of the actuating pin T emerges upward from the pump body 3: this exposed portion receives an actuator P which the user can push in order to move the actuating pin T axially back and forth in the pump body 3. Figure 1 In FIG. 1 , the actuator P is a nose-type actuator, but any actuator may be mounted on the actuator pin T. The actuator P is not critical to the present invention.

[0030] Here, the actuating pin T is of a special type, since it comprises a valve gate 1 at the upper part and a piston member 2 at the lower part. These two parts are connected to each other in a manner that they are free to move axially along the axis X. However, they are fixedly connected to each other in rotation, so that the rotation of the valve gate 1 causes the rotation of the piston member 2. And since the actuator P is firmly mounted on the valve gate 1, the rotation of the actuator P causes the actuating pin T to rotate as a whole.

[0031] More specifically, the valve gate 1 comprises a tube 11 extending upwardly from a base 13. Figure 4a , Figure 4b and Figure 4c The valve gate 1 can be better seen in the figure. The tube 11 forms a free end on which the actuator P is securely mounted axially and rotationally. It should be noted that the tube 11 forms a venting groove 12, the maximum dimension of which is axial. This venting groove 12 is located in the vicinity of the base 13. Its function will be explained below. The base 13 has an increased diameter compared to the diameter of the tube 11. The base 13 firstly comprises two longitudinal axial ribs 14 protruding radially outwards. The two ribs 14 are arranged diametrically opposite to each other. It should also be noted that the venting groove 12 is located axially directly above one of the ribs 14. Below the rib 14, the base 13 forms an annular groove 15 for receiving an O-ring G15, which can be Figure 1 Internally, the base 13 forms a housing 16 for another O-ring G16, which is also Figure 1 The gate 1 is moved internally by a through-duct 10 extending from the housing 16 to the free upper end of a tube 11 on which the actuator P is mounted.

[0032] The piston member 2 includes a head 21 and a tube 25. Figure 5a , Figure 5b , Figure 5c and Figure 5d The piston member 2 can be better seen in the figure. The head 21 forms a helical groove 22, the function of which will be provided below. Below the helical groove 22, the head 21 forms a groove 23 for receiving an O-ring G23, which can be Figure 1Seen in . Internally, the head 21 defines a receiving housing 20 forming two longitudinal axial recesses 24 intended to receive the two ribs 14 of the valve gate 1 in such a way that the two parts are locked to prevent them from rotating relative to each other. The recesses 24 have dimensions slightly larger than those of the ribs 14 in such a way that they can be received without play or excessive friction, so that the two parts can still move axially by sliding. At its bottom end, the tube 25 forms an inner housing 27 for the O-ring G27. At its top end, a movable valve member 26 is formed inside the tube 25, which will cooperate with the O-ring G16 of the valve gate 1 in such a way that together they form the outlet valve of the pump. As shown Figure 5d As can be seen in FIG. 2 , the receiving housing 20 communicates with the interior of the tube 25 via a passage formed around the movable valve member 26 , which is connected to the tube 25 via bridges of material.

[0033] exist Figure 6a , Figure 6b and Figure 6c The pump body 3 can be better seen in FIG. The pump body 3 internally defines a sliding cylinder 31, which has the particular feature of forming a helical thread 32 at its upper end. Above this helical thread 32, the pump body forms an axial stop (abutment) 33, which internally defines a housing 34 for an O-ring G34, which can be Figure 1 Below the sliding cylinder 31 , the main body 3 forms a fixing ring 35 (already described) and a mounting bushing 36 .

[0034] Now I will refer to Figure 1 as well as Figure 2a and Figure 3a, in order to explain the cooperation of these different parts in the pump of the present invention. As already mentioned, the base 13 of the valve gate 1 is axially engaged in the receiving housing 20 of the piston member 2, wherein the rib 14 is engaged by sliding in the recess 24 of the receiving housing 20. The maximum engagement of the base 13 in the receiving housing 20 results in a sealing contact between the O-ring G23 and the wall of the receiving housing 20, and a sealing contact between the O-ring G16 and the movable valve member 26. A slight axial displacement of the two components from this maximum engagement position results in the separation of the seal G16 from the movable valve member 26, while the O-ring G23 remains in sealing contact with the inner wall of the receiving housing 20. In other words, the neck seal G16 is disengaged, while the O-ring G23 slides in a sealing manner. Therefore, a seal is always maintained between the two components. This actuating pin T, which is constituted by the assembly of the valve gate 1 and the piston member 2, is integrated into the pump body 3 in the following manner. In the locked non-working state of the pump, the head 21 of the piston member 2 is threadedly engaged with the barrel 31. More precisely, the spiral thread 32 of the body 3 engages with the spiral groove 22 of the head 21 of the piston member 2. In this locked non-working state, it should be noted that the head 21 contacts the stopper 33. However, the O-ring G23 still remains in a sealed sliding contact state inside the cylinder 31. The tube 25 of the piston member 2 is engaged inside the sleeve 4 and slides in a sealed manner due to the O-ring G4. In addition, the tube 25 is also engaged around the cylinder 52 of the cylinder part 5 by the sliding sealing contact provided by the O-ring G27. Therefore, a fluid product chamber Cp is generated between the inlet valve 51 and the outlet valve formed by the O-ring G16 and the movable valve member 26. It can be said that the piston of the fluid product chamber Cp is formed by the O-ring G27 supported by the pipe 25.

[0035] The valve gate 1 protrudes through the stopper 33 together with its tube 11, and the base 13 of the valve gate 1 engages with the head 21 of the piston member 2. It should be noted that the base 13 can also contact the stopper 33. The O-ring G34 surrounds the tube 11, however, in this locked non-operating position, it should be noted that Figure 3a In the embodiment, the sealing contact between the O-ring G34 and the tube 11 is broken by the exhaust groove 12 axially located at the O-ring G34.

[0036] from Figure 1 , Figure 2a and Figure 3a In this locked non-operating position shown, the user can grasp the actuator P and drive it in rotation, thereby turning the piston member 2 inside the pump body 1 through the valve gate 1. In fact, due to the locking against rotation obtained by the engagement of the rib 14 in the recess 24, the torque applied to the actuator P is transmitted by the valve gate 1 to the piston member 2. This rotation applied to the actuator P causes the actuation of the threaded connection produced between the helical groove 22 and the helical thread 32. As a result, the actuator P and the actuating pin T are moved axially downwards. This is shown in FIG. Figure 2b and Figure 3b In. The helical thread 32 is completely disengaged from the helical groove 22, and then the head 21 and its O-ring G23 can slide axially in a sealed manner in the barrel 31 of the pump body 3 by axially pushing the actuator P. The space thus formed between the head 21 and the stopper 33 constitutes a partial vacuum chamber Cd, which appears as the actuator P rotates and is further increased by axially pushing the actuator P. Due to the O-rings G23 and G34, the partial vacuum chamber Cd is isolated from the outside, in this way so that as the head 21 moves away from the stopper 33, an increasing partial vacuum is generated. At the same time, the O-ring G27 slides along the barrel 52, thereby reducing the volume of the pump chamber Cp and increasing the pressure on the fluid product. In response to this increase in pressure, a slight axial displacement is generated between the piston member 2 and the valve gate 1, in this way the O-ring G16 is separated from the movable valve member 26, thereby generating an outlet channel for the fluid product through the valve gate 1 and the actuator P. Under the circumstances known in the prior art, the operation of this differential piston will not be described in more detail here.

[0037] Once the actuator P has been fully depressed, the dispensing of the fluid product is completed and the user then releases the pressure applied to the actuator P. The partial vacuum generated in the partial vacuum chamber Cd has the effect of returning the gate pin T to the non-working position. In other words, the partial vacuum generated in the partial vacuum chamber Cd pushes the head 21 of the piston member 2 in the direction of the stopper 33. The O-ring G23 thus moves in a sliding and sealing manner inside the barrel 31 until the head 21 enters into abutment against the stopper at the beginning of the helical thread 32. The user then knows that it is necessary to lock the pump again by rotating the actuator, which has the effect of bringing the helical thread 32 into tight connection with the helical groove 22. The end of the rotation corresponding to the locked non-working position is reached when the head 21 comes into contact again against the stopper 33. The construction then returns to Figure 1 , Figure 2a and Figure 3a The configuration shown, in which the partial vacuum chamber Cd reduced to a minimum volume state can communicate with the outside due to the lack of sealing created by the exhaust groove 12.

[0038] Therefore, the stroke of the actuating pin P makes it possible to change the volume of the partial vacuum chamber Cd between the minimum volume state, or even between zero volume and the maximum volume state. It can be similar to the movement of the head 21 of the partial vacuum chamber piston and its O-ring G23 serving as a piston lip, which can be decomposed into two parts, namely the main stroke corresponding to the sealing sliding without rotating components and the secondary stroke corresponding to the threaded engagement of the thread 32 in the groove 22. The main stroke is generated by the partial vacuum existing in the partial vacuum chamber Cd, while the secondary stroke is generated by the manual drive of the actuator P to rotate. In other words, the main stroke is only pneumatic, while the secondary stroke is basically mechanical. Therefore, the threaded engagement between the thread 32 and the groove 22 can be defined as a mechanical device as opposed to the pneumatic device of the main stroke. The mechanical device formed by the thread 32 and the groove 22 makes it possible to return the actuating pin T to the locked non-working position in a reliable manner, in which the partial vacuum chamber Cd reduced to its minimum volume state is connected to the outside via the exhaust groove 12. By reference Figure 3a It can be easily understood that this communication with the outside is disconnected very quickly as soon as the exhaust groove 12 is no longer axially located at the O-ring G34. A stroke of a few tenths of a millimeter is sufficient to disconnect this communication and isolate the partial vacuum chamber Cd from the outside. The exhaust of the partial vacuum chamber Cd makes it possible to reset the pressure at each actuation of the pump. Therefore, even in the case where the partial vacuum chamber Cd could leak and could therefore allow air to enter inside, this air will be evacuated at the end of the actuation thanks to the exhaust of the chamber Cd through the exhaust groove 12.

[0039] Operation of the pump is possible without the mechanical means constituted by the thread 32 and the groove 22, but in this case the partial vacuum in the partial vacuum chamber Cd must be sufficient to bring the head 21 into contact with the stop 33, in such a way that communication with the outside is reestablished through the groove 12. Conversely, the pump can be operated without the exhaust groove 12, but in this case there must be no leakage at the partial vacuum chamber Cd. Obviously, the cumulative use of the mechanical means and exhaust is particularly advantageous and constitutes a preferred embodiment.

[0040] The pump described herein includes a piston member 2 which may be described as a differential piston because it moves not only by pushing on an actuator but also by responding to a critical pressure within the fluid product chamber Cp. Without departing from the scope of the invention, the partial vacuum chamber Cd of the present invention may be employed in a more conventional pump in which the piston of the partial vacuum chamber is securely mounted on an actuation pin while the piston of the fluid product chamber Cp is slidably mounted on an actuation pin.

[0041] Without departing from the scope of the present invention, there may be provided a plurality of venting grooves 12 and one or more than two ribs 14. The O-rings employed on the various components may be replaced with integral lips.

[0042] Thanks to the invention, it is possible to replace the metal or plastic springs of the prior art with air springs, part of the travel of which is produced by the actuation of an actuator, which is preferably rotary. However, it is also possible to envisage moving the actuator only in the axial direction. With regard to exhausting the partial vacuum chamber Cd, it allows resetting at each actuation.

Claims

1. A pump comprising a fluid product chamber (Cp) with a variable volume and an actuating pin (T), the actuating pin (T) being axially movable between a non-operating position and a depressed position, in such a way that the volume of the fluid product chamber (Cp) varies between a maximum volume state and a minimum volume state, respectively, the pump comprising a return device (Cd) for returning the actuating pin (T) to the non-operating position corresponding to the maximum volume state of the fluid product chamber (Cp), the actuating pin (T) being equipped with an actuator (P) actuable by a user, wherein the return means comprises a partial vacuum chamber (Cd) having a volume which varies between a minimum volume state and a maximum volume state by displacement of the actuating pin (T), the minimum volume state of the partial vacuum chamber (Cd) being reached in the inoperative position of the actuating pin (T) and the maximum volume state of the partial vacuum chamber (Cd) being reached in the depressed position of the actuating pin (T), the maximum volume state of the partial vacuum chamber (Cd) corresponding to a maximum partial vacuum and the minimum volume state of the partial vacuum chamber (Cd) corresponding to a minimum partial vacuum, the actuating pin (T) being pushed towards its inoperative position by the partial vacuum existing in the partial vacuum chamber (Cd), wherein mechanical means (22, 32) independent of the partial vacuum in the partial vacuum chamber (Cd) can be actuated by the user in order to return the partial vacuum chamber (Cd) to and maintain it in its minimum volume state, It is characterized in that The mechanical device comprises a threaded connection (22, 32) which enables axial and rotational movement of the actuating pin (T) and its actuator (P).

2. A pump according to claim 1, wherein said mechanical device (22, 32) is controlled by said actuator (P) via said actuating pin (T).

3. A pump as claimed in claim 1 or claim 2, wherein the threaded connection (22, 32) limits an axial stroke, which is delimited on one side by a top stop (33) corresponding to the minimum volume state of the partial vacuum chamber (Cd) and on the other side by the release of the threaded connection, thereby allowing a subsequent change of the volume of the partial vacuum chamber (Cd) towards its maximum volume state.

4. A pump according to any one of the preceding claims, wherein the partial vacuum chamber (Cd) communicates with the outside in its minimum volume state.

5. A pump as claimed in any one of the preceding claims, wherein the actuating pin (T) comprises a partial vacuum chamber piston (G23) which slides axially in a sealed manner in the cylinder (31) of the partial vacuum chamber, thereby defining the partial vacuum chamber (Cd) therebetween, and the actuating pin (T) forms an exhaust groove (12) which connects the partial vacuum chamber (Cd) to the outside when the actuating pin (T) is in a non-operating state.

6. A pump as described in any of the preceding claims, wherein the actuating pin (T) includes a valve gate (1) and a piston member (2), the piston member (2) forming a partial vacuum chamber piston (G23) sliding in the barrel (31) of the partial vacuum chamber, the piston member (2) also forming a fluid product chamber piston (G27) sliding in the fluid product chamber barrel (4), the piston member (2) advantageously forming a movable outlet valve member (26) of the fluid product chamber (Cp), and the valve gate (1) advantageously forming an outlet valve seat (G16) of the fluid product chamber (Cp).

7. A pump according to claim 6, wherein the piston member (2) is axially movable relative to the valve gate (1) under the effect of the pressure existing in the fluid product chamber (Cp), but is driven in rotation by the valve gate (1).

8. A pump as claimed in claim 6 or claim 7, wherein the threaded connection (22, 32) is located between the piston member (2) and the barrel (31) of the partial vacuum chamber.

9. A pump according to any one of the preceding claims, wherein the partial vacuum chamber (Cd) defines a maximum axial travel between its minimum volume state and its maximum volume state, the maximum axial travel being decomposed into: - a main stroke starting from said maximum volume state caused by the partial vacuum existing in said partial vacuum chamber (Cd), and - a secondary stroke to reach the maximum volume state, the maximum volume state being brought about by driving the actuator (P) rotationally and / or axially, the secondary stroke terminating in an axially locked position of the actuator (P).

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