JP2007515286A - Fluid dispenser member - Google Patents

Abstract

A pusher (120; 220; 320), a push wall (121; 221; 321) formed with a push outer surface (1211; 2211; 3211) and an inner surface (1212; 2212; 3212); and A pusher having a peripheral skirt (122; 22; 322) extending from the inner surface of the push wall; a pump chamber (1) with inlet and outlet valves; and a dispensing opening ( 125; 225; 325), a main piston (136; 236; 336) that changes the volume of the pump chamber, and a difference installed to move in the pump chamber in response to changes in pressure in the pump chamber Moving piston (131,132,133; 231,232,233; 331,332,333), pump chamber A differential pump installed to move away from the push wall when the pressure of the fluid increases (100; 200; 300), wherein the pusher and the differential piston are located on the push wall. It is arranged to move along a drive axis (X) extending in a generally vertical direction, characterized in that the differential piston cooperates with the inlet valve seat (1161; 2161; 3161). The fluid pump, wherein the fluid pump is formed integrally with the inlet valve moving member (138; 238; 338).

Description

  The present invention relates generally to fluid dispenser pumps that are designed to be combined with a fluid container and together constitute a fluid dispenser. Typically, it is the dispenser member that is manually driven by the user with a finger. The fluid is administered in the form of a fine droplet spray, a continuous trickle, or a mass of fluid (especially in the case of viscous fluids such as cosmetic creams). Such fluid dispenser members are used in particular in the field of perfumes, cosmetics, especially medicines, and can dispense fluids of varying viscosity.

  More specifically, the present invention relates to a dispenser member of the type referred to as a “pusher pump”. However, the present invention is not limited to this. The above name is explained by the fact that the pusher of the dispenser member not only forms the dispensing opening, but also forms part of the fluid chamber in which the fluid is selectively pressurized. be able to. When the dispenser member is a pump, the chamber is a pump chamber. The peculiarities of such pusher pumps lie in the following facts. That is, the inner surface of the pusher (the overall shape of the surface is substantially cylindrical) acts as a leak-proof slide cylinder for the piston, and the piston moves in a leak-proof contact with the inside of the cylinder. The fact is that the dosing opening is thereby selectively opened. Normally, the piston here is a differential type piston that moves in response to a change in pressure of fluid in the chamber. The differential piston should be distinguished from the main piston which is moved by driving the pusher. That is, such a pusher pump includes a differential piston and a main piston, and these pistons can move in respective cylinders in a leak-proof contact state. The main cylinder for the main piston can also be formed by a pusher.

  This is especially true for the pumps described in the patent document: WO 97/23304. The pusher has a push wall, and pressure is applied to the push wall with a finger for the purpose of driving the pusher. Further, the pusher has a skirt extending downward from the push wall. The skirt forms a first leak-proof slide cylinder for the differential piston and a second main cylinder for the main piston of the pump. The differential piston is separated from the main piston. The differential piston is pushed in a direction away from the push wall by a spring, which acts as both a return spring and a precompression spring. The slide cylinder for the differential piston has an outlet duct that leads to a nozzle housed in a recess formed in the pusher skirt. The nozzle is formed with a dispensing opening through which fluid is discharged from the dispenser member. In addition, the recess formed in the skirt has a vortex system. The system cooperates with the nozzle to vortex the fluid at the stage prior to being discharged through the dosing opening. The vortex system is made in the conventional manner from one or more tangential vortex channels that open into the vortex chamber and are precisely centered at the dosing opening. The vortex system takes the form of a recessed network with a recess inside the skirt. The recessed network is then combined with a separate nozzle (the nozzle will separate the vortex channel from the chamber). Thus, the slide cylinder of the differential piston is in the form of a cylindrical surface except for the position of the outlet channel. When the pusher is pushed, the main piston rises inside the main cylinder of the pusher, whereby the differential piston is moved in a manner that slides inside the differential cylinder in a leak-proof manner. As a result, the spring is compressed. Then, the differential piston moves upward toward the pusher push wall. The active sealing lip of the differential piston (which directly contacts the fluid) slides in the lower portion of the cylinder located below the outlet channel. As soon as the differential piston reaches the outlet duct, the fluid under pressure in the chamber is pumped out of the chamber through the duct and reaches the nozzle. Then, after being swirled there, it is discharged via the administration opening.

Patent Document: The pump in WO 97/23304 has five basic components: a body designed to be combined with a fluid reservoir, a pusher, a ball forming an inlet valve member, a differential piston, and Nozzle). A main piston is formed in the main body.
US-4 050 613 also describes a pusher, a body fixed in a fixed manner by a ring at the position of the receiving opening, and the inside of the pusher and above the body in a sliding manner in response to pressure fluctuations. A pump having a differential piston installed in The body, pusher, and differential piston together form a chamber. As the pressure inside the chamber increases, the differential piston moves away from the pusher. Furthermore, the inlet valve of the chamber is formed by a flap valve that deforms when the chamber is held down. This valve is formed by an additional part installed on the body. The preamble of claim 1 is based on this document.

  The object of the present invention is to improve the pump disclosed in the patent publication US-4 050 613, i.e. to reduce the number of components and to optimize the overall operation of the pump.

  As a first aspect, the present invention provides the feature of claim 1 (that is, the feature that the differential piston is formed integrally with an inlet valve moving member that cooperates with the inlet valve seat). A fluid pump is provided.

  The prior art inlet valve described above is formed in such a way that a separate ball or flap rests on the seat. Specifically, it is possible to form an inlet valve moving member with a differential piston, as the pressure in the pump chamber increases, the differential piston moves away from the push wall. is there. This contributes to the movement of the inlet valve moving member in the direction of the inlet valve seat.

  As another aspect of the present invention that can be implemented separately or in combination with the features described above, the push wall forms the wall member of the pump chamber. In the prior art document, the space formed between the differential piston and the push wall is a dead space that does not perform any function. By extending the pump chamber to the push wall, the space formed in the pusher is optimized. There is no longer a dead volume, and as a result, the size of the pusher is reduced and the size of the pump is accordingly reduced.

  As another aspect of the present invention, which can be implemented separately or in combination with the above features, the differential piston is provided with at least one fluid passage hole. The fluid passage hole allows the pump chamber to extend to the push wall. Furthermore, this makes it possible to reverse the movement of the differential piston as compared to the case of the above-mentioned prior art document. Thus, the differential piston can move away from the push wall as pressure increases in the pump chamber.

  Also, in an advantageous embodiment, the pusher skirt has an inner surface that forms a leak-proof slide cylinder, the dosing opening is formed in the slide cylinder, and the differential piston is located inside the cylinder. By having at least one sealing lip that is in a leak-proof sliding contact state, the administration opening is opened when the differential piston moves away from the push wall. It should be noted that the sealing lip of the follower piston moves into the upper part of the cylinder located between the dosing opening and the push wall. In the above prior art, the opposite is true. Furthermore, the dosing opening is formed directly inside the slide cylinder and is not in a separate nozzle.

  In another embodiment, the differential piston has a disk that is substantially perpendicular to the drive shaft, and the disk is installed to move away from the push wall when pressure increases in the pump chamber. And the disk has a pressure surface disposed opposite the inner surface of the push wall, the disk having at least one through fluid passage hole so that a portion of the pump chamber is part of the push wall The outer peripheral edge of the disk is formed with at least one sealing lip that is in sliding contact with the inside of the pusher skirt.

  As another advantageous aspect of the present invention that can be implemented separately from the above-described features, a differential piston is formed integrally with the main piston, and the main piston is resistant to the inside of the main cylinder. It has a sealing lip that contacts the leaking slide. This is not the case with the above-mentioned prior art document where the main piston is formed by a body independent of the differential piston.

Further, as an effective feature of the present invention, it further includes a main body designed to be combined with the fluid container, and the return spring is in contact with the main body at one end and the differential piston at the other end. The return spring is advantageously formed in one piece with the differential piston or body.
In another advantageous aspect of the present invention, the inner surface of the skirt forming the pusher slide cylinder is provided with a vortex system centered on the dispensing opening, said system comprising a pusher skirt. It is formed in an integrated shape. This feature is particularly effective in combination with the fact that the differential piston moves away from the push wall as the pressure increases in the pump chamber. The inner surface of the pusher forming the slide cylinder of the differential piston is usually made of an injection molded plastic material. For this purpose, a mold made of a plurality of members is used. One of the members specifically forms a core for forming the inner surface of the pusher. In the present invention, the core must form not only a slide cylinder but also a vortex system. Since the vortex system extends to form a recessed portion inside the slide cylinder of the differential piston, the core must be formed with a corresponding negative imprint protruding outward. Furthermore, when the core is pulled out in the mold extraction, the protruding imprint must be pulled out with force. Therefore, the protruding imprint must come out of the recess portion formed by it, and must be moved along the lower portion of the slide cylinder. The plastic material can be creeped, so even if the protruding imprint is forced, there will be little trace on the slide cylinder. However, the possibility of leaving traces is not zero. Ensuring that the differential piston moves away from the push wall necessarily entails that the sealing lip of the differential piston in contact with the fluid is above the cylinder located between the vortex system and the push wall. It means to move into the part. Eventually, the upper part is unaffected by the withdrawal of the core and is inevitably intact. Thus, the differential piston is guaranteed to slide in a full cylinder surface quality and is not damaged in any way by the molding core used to form the vortex system.

  In another advantageous embodiment of the invention, the differential piston is formed by a piston member, the piston member further comprising a valve rod, the rod being axially away from the pressure surface, The rod extends concentrically, and the rod cooperates with the valve seat to form an inlet valve. Further, the piston member may further comprise a bushing, the bushing surrounding the valve rod and extending concentrically, the bushing forming the main piston in the form of a sealing lip. Thus, the integral part, i.e. the piston member, simultaneously forms the differential piston, the main piston and the moving member of the inlet valve. Such a structure is different from that found in the above-mentioned prior art documents.

  As another feature, the inlet valve rod is guided axially within the sleeve.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings showing embodiments of the present invention as non-limiting examples.
The dispenser member of the first embodiment shown in FIGS. 1 and 2 is a pump combined with a container 150 having a main body 151 in which a fluid container 5 is formed. The main body 151 is provided with an opening in the form of a neck 153 at its upper end, which neck serves to fix the dispenser member according to the invention.

  The pump has three components. That is, the main body 110, the pusher 120, and the piston member 130. The dispenser member further comprises spring means in the form of a coil spring 140. The main body, the pusher and the piston member are preferably made of a plastic material. The pump has a pump chamber 1. The main body 110 includes a fixing ring 111, which cooperates with the neck 153 to fix the member to the container 150. The ring 111 is fitted to the outside of the neck 153. In addition, a self-sealing lip 112 is formed on the main body, and is fitted on the inner wall of the neck 153 in a leak-proof manner. A guide band 114 is also formed in the main body 111, and the band extends in a straight line with the ring 111 as an effective configuration. A rim 1114 extending inward is provided at the upper end of the guide band 114. A bushing 113 is also formed in the main body 110, and the bushing extends inside the guide band 114 and concentrically therewith. Thereby, an annular gap is formed between the band 114 and the bushing 113. The bushing 113 has a shoulder 1131 at its upper end, and the shoulder serves as a surface for receiving the spring 140. A main cylinder 117 is formed at the tip of the bushing 113 extending upward. A leak-proof slide surface is formed inside the cylinder, and its function will be described later. A dip tube 115 is further formed in the main body, and the tube extends inside the container 150. At its upper end, the tip of the dip tube 115 extends to an inlet sleeve 116, on which an inlet valve profile or seat 1161 is formed. The inlet duct 118 passes through the dip tube 115 and the sleeve 116. The inlet sleeve 116 extends concentrically with the inside of the main cylinder 117. As a result, an annular space is formed between them.

The body 110 is axially and circularly symmetric with respect to the axis X extending in the longitudinal direction at the axial center of the inlet duct 118.
This is a specific design for the specific body of the dispenser member in the first embodiment of the invention. Of course, the body may have different characteristics than those described above without departing from the scope of the present invention.

  Pusher 120 forms a dispenser head for the dispenser member. The pusher 120 has a push wall 121 and a peripheral skirt 122, and the skirt extends downward from the outer peripheral edge of the push wall. As a result, the pusher 120 is generally shaped like a cup upside down, with the push wall forming the end wall and the skirt forming the cylindrical side wall. However, the shape of the skirt is not necessarily cylindrical. It can also be a truncated cone shape or a shape with a rounded cross section.

The push wall 121 has a push outer surface 1211, and the outer surface can be pressed with one or more fingers. In addition, the push wall 121 has an inner surface 1212 on which a receiving stud 1213 is formed as an effective configuration.
The skirt 122 has a dosing top wall 123 and a guide bottom wall 124. At its upper end, the administration wall 123 is connected to the outer peripheral edge of the push wall 121. The administration wall 123 has an outer surface 1221 and an inner surface 1232. Inner surface 1232 is preferably a round cylinder and forms a slide cylinder as described below. In addition, the dosing wall 123 is provided with a through-dose opening 125 that extends from the inner surface to the outer surface. The dispensing opening 125 can be shaped to open into the dispensing dish 1251 on the outer surface.

  According to an advantageous feature of the present invention, the inner wall 1232 of the dosing wall 123 is provided with a vortex system 126 that rotates the fluid into a vortex state with the center of its “eye” being the dosing center. It can come to the position of an opening part. Thus, as an effective configuration, the administration wall 123 is formed integrally with the push wall 121 and the guide wall 124, has a through-dose opening, and is provided with a vortex system on the inner surface. .

  A receiving bead 1241 is provided on the outer surface of the guide wall 124 and works in cooperation with an inwardly extending rim 1141 of the guide band 114. The guide wall 124 is disposed in an annular gap formed between the guide band 114 and the bushing 113. The pusher can be fastened to the main body by the receiving bead 1241, so that the pusher is connected to the lower end of the guide wall 124 and the end wall of the annular gap (formed between the band 114 and the bushing 113). It is only possible to move in the axial direction over the maximum stroke defined by the distance between.

  The piston member 130 in the present embodiment has a leak-proof slide in a cylinder formed by a main piston 136 fitted in a form that slides in the main cylinder 117 in a leak-proof manner and an inner surface 1232 of the administration wall 123. And a differential piston formed by two lips 132, 133 in contact. As an effective configuration, the piston member 130 is formed in the form of an integrated single part. The lips 132, 133 extend in such a way that one is above the other and there is a greater spacing between the two than the axial width of the vortex system 126. In the rest position shown in FIG. 1, upper lip 132 is in contact with inner surface 1232 above vortex system 126, while lower lip 133 is in contact with inner surface 1232 below vortex system 126. become. This prevents the vortex system from communicating with the interior of the pusher at locations other than the space formed between the two lips 132, 133. This is the rest position, where the piston member 130 is pressed against the push wall 121 under the force of the spring 140. The spring is in contact with the shoulder 1131 at one end, and is in contact with the lower side of the disk 131 formed on the piston member 130 at the other end. Further, the two lips 132 and 133 are formed on the outer peripheral edge of the disk 131. At the center, the disc is received by a receiving stud 1213 formed on the inner surface 1212 of the push wall 121. The differential piston is considered to be formed by a disk 131 on which two lips 132 and 133 are formed. The piston member 130 is also formed with an axial central rod 137 that extends from the disk 131 away from the push wall 121. A part of the axial rod 137 is fitted inside an inlet sleeve 116 formed in the main body 110. The rod 137 is formed with a valve profile 138 that cooperates with a profile 1161 formed in the sleeve 116 correspondingly. In other words, the rod 137 cooperates with the sleeve 116 to form an inlet valve for the pump chamber 1, as will be described below. In addition, a piston bushing 135 is formed on the piston member 130, and a main piston 136 is formed on the lower end thereof. The piston bushing 135 surrounds the axial rod 137 and extends concentrically therewith. Thereby, an annular duct is formed between the two, and the duct extends through the disk 131 through the fluid passage hole 134.

  Body 110, pusher 120, and piston member 130 together form pump chamber 1, which is between main cylinder 117 and sleeve 116, between piston bushing 135 and axial rod 137, and through hole 134. And extends between the disk 131 and the inner surface 1212 of the push wall 121 in a seamless manner. Thus, the top surface and the inner surface 1212 of the disk 131 form a wall member of the pump chamber 1. In the rest position shown in FIG. 1, the spring 140 pushes the piston member 130 to be received by the push wall 121. The inlet valve formed by the cooperation between the axial rod 137 and the sleeve 116 is open. The two lips 132, 133 of the differential piston are in contact with the cylinder formed by the inner surface 1232 of the drive wall 123, as indicated by the dotted line in FIG.

  When a force is applied to the push outer surface 1211 of the push wall 121, the pusher is moved in the axial direction with respect to the main body 110. Since the piston member is received by the push wall, the piston member is pushed by the pusher. In the first stage, the inlet valve is closed by the movement of the pusher. That is, the axial rod 137 fits deeper into the sleeve 116, and finally a leak-proof sliding contact is realized between the sleeve and the rod. Thus, the pump chamber 1 is separated from the container 5. From this point, the fluid in the pump chamber 1 is under pressure. Since the fluid is incompressible, the overall working volume of the pump chamber is kept constant. However, since the main piston 136 enters the cylinder 117, thereby reducing the volume of the lower portion of the chamber, a new space must be created. This is made possible by the fact that the differential piston moves away from the push wall 121. As a result, the lips 132 and 133 slide and move inside the administration wall 123. Thus, the lip moves until the upper lip 132 reaches the vortex system 126. This is shown in FIG. From there, the fluid under pressure in the pump chamber finds an exit passage through the vortex system and the dosing opening. The position of the upper lip 132 is indicated by a dotted line in FIG. Thus, the passageway remains open as long as the pressure in the chamber exceeds the force of the spring 140. As soon as the pressure in the chamber drops and falls below a certain threshold, the spring 140 pushes the differential piston back toward the rest position shown in FIG. 3 (a). The vortex system and dosing opening are then again separated from the pump chamber.

  It should be noted that the upper lip 132 is in direct contact with the fluid, while the lower lip is not in direct contact with the fluid. Thus, the upper lip slides in the upper part of the cylinder formed between the push wall and the vortex system. The surface quality of the upper part is better than the surface quality of the lower part extending below the vortex system. The lower part may be damaged by removal of the molding core.

  Shown in FIGS. 3 (a) and 3 (b) is a specific, non-limiting embodiment relating to a vortex system formed in the dosing wall of the dosing member of the present invention. The vortex system has at least one tangential vortex channel 1262. In the figure, three tangential channels are arranged with a uniform angular spacing. The vortex system further includes a central vortex chamber 1261 that is precisely centered with respect to the dispensing opening 125. Also, as an optional configuration, the vortex system may further include a peripheral feed ring 1263 that allows feeding of all vortex channels 1262. Also, if necessary, the vortex system can be made smaller to have only a single vortex channel combined with a central vortex chamber.

  An effective characteristic of the present invention resides in that the piston member 140 pressed against the push wall 121 moves in a direction away from the push wall under the influence of an increase in pressure inside the pump chamber. Specifically, this is made possible by the fluid passage hole 134 provided so as to penetrate the disk 131 forming the differential piston. Thus, it can also be said that the push wall forms the wall member of the pump chamber.

  A differential piston combined with a vortex system formed in the dosing wall and moving away from the push wall in this way is effective for removal from the mold. This is because the upper lip 132 slides over the upper part of the slide cylinder in a leak-proof manner, and the upper part has a molding core with a “negative” imprint (vortex system). This is because there is no risk of damage by pulling out the molding).

Also, it should be noted that the rest position is reached at a timing when the receiving bead 1241 formed on the guide wall 124 is received under the rim 1141 extending inward.
Furthermore, it is the guide walls 124 that are guided axially between the band 114 and the bushing 113, and secondly that each guarantees the axial guide of the pusher, and secondly the main cylinder 117. A piston bushing 135 and an axial rod 137 which are fitted into the inlet sleeve 116.

4 (a) and 4 (b) show modifications of the embodiment shown in FIGS.
In the variant shown in FIG. 4 (a), the return and pre-compression spring is formed integrally with the body 210 and is given the reference number 2171. The spring extends in line with the main cylinder 217 and is received on the lower side of the disk 231 that forms a differential piston with the two lips 232, 233. Thus, the spring 2171 extends concentrically with the bushing 230 forming the main piston 236. Except for the return spring, the dispenser member 200 of FIG. 4A may be the same as the dispenser member of FIGS.

  In the embodiment of FIG. 4B, the dispenser member 300 has a return spring 3311 formed integrally with the piston member 330. More precisely, the spring 3311 extends from the bottom surface of the disk 331. This is shaped to be received by a shoulder 3331 formed on the main body 310 at the lower end thereof. The dispenser member 300 may be identical to the dispenser member of FIGS. 1 and 2 except that the spring has a special shape.

  In the variant embodiment of FIGS. 4 (a) and 4 (b), the dispenser member has only three components: the body, the pusher, and the piston member, which are the return and pre-compression springs. This is because is integrally formed with the main body or the piston member.

It is a longitudinal cross-sectional view which shows 1st Embodiment of a dispenser member in a rest state, and is a figure shown in the form combined with the fluid container which shows only one part. It is a figure similar to FIG. 1, and is a figure shown in a driven position. (A) It is the schematic which shows the inner surface of the administration wall provided with the vortex system of this invention, and is a figure shown in a rest position. (B) Schematic view showing the inner surface of the dosing wall with the vortex system of the present invention, in a driven position. (A) It is a longitudinal cross-sectional view which shows embodiment of the modification of a dispenser member. (B) It is a longitudinal cross-sectional view which shows embodiment of another modification of a dispenser member.

Claims (13)

A pusher (120; 220; 320), a push wall (121; 221; 321) formed with a push outer surface (1211; 2211; 3211) and an inner surface (1212; 2212; 3212); and A pusher having a peripheral skirt (122; 22; 322) extending from the inner surface of the push wall;
A pump chamber (1) with an inlet valve and an outlet valve;
A dosing opening (125; 225; 325) that is a passage for the fluid to be dispensed;
A main piston (136; 236; 336) that changes the volume of the pump chamber; and
A differential piston (131, 132, 133; 231, 232, 233; 331, 332, 333) installed so as to move in the pump chamber in response to a change in pressure in the pump chamber, The differential piston installed to move away from the push wall when the pressure increases,
A fluid pump (100; 200; 300) comprising:
The pusher and the differential piston are installed so as to move along a drive shaft (X) extending substantially perpendicular to the push wall.
The feature is
The differential piston is formed in one piece with the inlet valve moving member (138; 238; 338) cooperating with the inlet valve seat (1161; 2161; 3161);
Said fluid pump. A differential piston is formed by a piston member (130; 230; 330), the piston member further comprising a valve rod (137; 237; 337), the rod axially away from the pressure surface, and Extending concentrically, the rod cooperating with the valve seat to form an inlet valve;
The fluid pump according to claim 1. The piston member further comprises a bushing (135), which surrounds the valve rod and extends concentrically, said bushing forming the main piston in the form of a sealing lip;
The fluid pump according to claim 2. The inlet valve rod is axially guided in the sleeve (116);
The fluid pump according to claim 2 or 3. The differential piston has a disk (131; 231; 331) that is substantially perpendicular to the drive shaft, the disk being installed to move away from the push wall when the pressure increases in the pump chamber. And the disc has a pressure surface (1312; 2312; 3312) disposed opposite the inner surface (121; 2212; 3212) of the push wall, the disc being a through fluid passage hole (134; 234). 334), a part of the pump chamber is formed between the push wall and the disk, and the outer peripheral edge of the disk has a sealing lip (slip-proof sliding contact inside the pusher skirt). 132, 133; 232, 233; 332, 333) are formed,
The fluid pump according to any one of claims 1 to 4. The differential piston is formed integrally with the main piston, and the main piston has a sealing lip that is in a leak-proof sliding contact inside the main cylinder;
A fluid pump according to any one of claims 1 to 5. It further has a body (110, 210; 310) designed to be combined with the fluid container (5), the return spring (140; 2171; 3311) being at one end to the body and at the other end to a differential piston. Being in contact with
A fluid pump according to any one of claims 1 to 6. The return spring is formed integrally with the differential piston or body;
The fluid pump according to claim 7. The body includes an inlet valve seat (1161; 2161; 3161), a main cylinder (117; 217; 317) for the main piston, a high abutment (1141) for the pusher, and a pusher Axial guide means (113, 114) for fixing, fixing means (111) for fixing to the container, and dip tube (115) are formed,
The fluid pump according to claim 7 or 8. The inner surface of the skirt forming the pusher slide cylinder is provided with a vortex system (126; 226; 326) centered on the dosing opening, said system being integrated in the pusher skirt. Formed in the
The fluid pump according to any one of claims 1 to 9. The push wall forms the wall of the pump chamber;
The fluid pump according to any one of claims 1 to 10, wherein: The differential piston is provided with at least one fluid passage hole (134; 234; 334);
The fluid pump according to claim 1, wherein: The skirt of the pusher has an inner surface (1232; 2232; 3232) that forms a leak-proof slide cylinder, the dosing opening is formed in the slide cylinder, and the differential piston is leak-proof slide inside the cylinder. By having at least one sealing lip (132, 133, 232, 233; 332, 333) in contact, the dosing opening can be opened when the differential piston moves away from the push wall ,
The fluid pump according to any one of claims 1 to 12.

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