Abstract: An airless dispenser pump assembly includes a pump mechanism with an inlet valve that is configured to efficiently pump viscous fluids and that is able to be pre-primed when the pump mechanism is attached to a container. In one form, the inlet valve includes a seal member that seals an inlet port of the pump and an outer support member that secures the inlet valve to the rest of the pump mechanism. Two or more legs generally extend in a circumferential direction between the support member and the seal member in order to create a large flow opening for fluid flow through the inlet valve when opened and to rapidly close the inlet valve. The pump mechanism further includes an outlet valve that is configured to draw fluid back from a nozzle of the pump after dispensing in order to minimize build up around the nozzle.

Abstract: An accumulator-type liquid sprayer includes a piston arranged in a cylinder, a piston guide extending through a passage extending therethrough in an axial direction of the piston, so as to be engageable with, and disengageable from the piston, cooperating with the piston and the cylinder to form a space region for sucking and pressurizing a liquid, a check valve for opening a suction port of the cylinder during suction of the liquid, and a hollow stem slidably fitted with an outer side of the piston in a liquid-tight manner and engaging with an end portion of the piston guide. A first resilient member urges the piston guide against the piston for maintaining a closed state of the passage in the piston, and a second resilient member urges the piston against the piston guide for adjusting a spraying pressure of the liquid.

Abstract: A dispenser with a sealed dispensing valve unit is disclosed. The dispenser is secured to a mouth of a hermetic casing, and discharges contents through a center of an upper plate of a button. The dispenser includes an outlet hole (100) bored in a central portion of the button. An inclined inner surface defines a lower portion of the outlet hole, and a vertical inner surface extends from an upper end of the inclined inner surface to a predetermined height. The dispenser also includes a dispensing valve (200) having at a lower portion thereof an inclined outer surface to selectively come into contact with the inclined inner surface of the outlet hole due to operation of a pumping means, thus opening or closing the outlet hole. Further, a vertical outer surface extends upwards from an upper end of the inclined outer surface to a predetermined height.

Abstract: The invention relates to a pump intended to be mounted on a bottle so as to enable a liquid contained in said bottle to be dispensed, said pump including a pump body, an atomizer secured to a push button, a means for the elastic return of the translatory motion of said atomizer in said body, and a plunger mounted in frictional contact against the internal surface of said body so as to define a dosing chamber which is in communication with the liquid by means of a clack valve, wherein the plunger is mounted coaxially around the atomizer in an association zone, said association zone being arranged so as to enable sealed swiveling between the plunger and the atomizer.

Abstract: A fluid dispenser comprising: a fluid reservoir (2) for containing fluid, the reservoir including an opening (230) having an outer top edge (25) and an inner bottom edge (26); a dispenser member (3), such as a pump or a valve; fastener means for fastening the dispenser member in the opening (230); the dispenser being characterized in that it further comprises tamperproofing means (1) that are distinct from the fastener means and that are secured to the dispenser member (3), the tamperproofing means coming into contact with the inner edge (26) in the event of an attempt at removing the dispenser member (3) from the opening (230).

Abstract: A vacuum controlled valve mechanism providing two separate one-way valves, one for each of a pair of collapsible fluid containing reservoirs with each valve being in an initial sealed condition preventing flow therethrough until by operation of the pump mechanism a threshold vacuum is exceeded and with the threshold vacuum of a first of the valves being greater than the threshold vacuum of the other, second of the valves. When the threshold vacuum of the first valve is exceeded, that first valve separately permits dispensing of fluid from its reservoir under vacuum conditions less than the threshold vacuum of the first valve and the second valve until the first reservoir is substantially empty after which further operation of the pump mechanism creates a vacuum which exceeds the threshold vacuum for the second valve after which the second valve permits dispensing of fluid from the second reservoir.

Abstract: A liquid dispenser device for being associated with a liquid reservoir, said device comprising: a chamber (10) provided with an inlet valve (5, 15), an outlet valve (27, 32), and a piston (3) that is suitable for varying the volume of the chamber (10); a liquid dispenser orifice (25); and a pusher (2) that is axially displaceable down and up between a rest position and a depressed position; the dispenser device being characterized in that the piston (3) includes an elastically-deformable portion (31) that is deformed by the pusher (2) in its depressed position, in such a manner as to open the outlet valve.

Abstract: A liquid dispenser device for being associated with a liquid reservoir (R), said device comprising: a chamber (10) provided with an inlet valve (5, 15), an outlet valve (32, 232), and a piston (3) that is suitable for varying the volume of the chamber; a liquid dispenser orifice (25); and a pusher (2) that is axially displaceable down and up between a rest position and a depressed position; the dispenser device being characterized in that the pusher (2) includes an elastically-deformable wall (212) that is thus displaceable relative to the remainder of the pusher, the piston (3) being in contact, at least momentarily, with the deformable wall (212), so as to be urged in displacement relative to the remainder of the pusher while the wall is being deformed, in such a manner as to open the outlet valve.

Abstract: A dispensing assembly has a ferrule and collar for maintaining a coupling of a dispensing module to a receptacle neck. The ferrule has an annular plastic skirt open on one end, and plastic nibs extending radially inwardly from the skirt inner surface. The skirt outer surface is a regular polygon with flat surfaces between corners. The collar has a Nomar edge defining an annular recess adjacent the open end with an annular face facing the collar other end. At least the corners of the skirt open end extend radially outwardly into the annular recess of the collar inner surface when the dispensing assembly is secured to the receptacle to retain the collar on the ferrule while the dispensing assembly is secured to the receptacle by the ferrule nibs beneath the flange of the receptacle neck. Installation involves pushing the collar and ferrule onto the receptacle neck with the collar in a raised position on the ferrule, and then pushing the collar down relative to the ferrule.

Abstract: A self-contained viscous liquid dispenser with a spray pump mechanism includes a housing defining an internal liquid reservoir. A spray pump mechanism is configured with the housing and includes a horizontally disposed pump chamber fitted through an opening in the housing to extend into the reservoir. A pump cylinder is slidably disposed and retained in the chamber. Upon actuation of the pump cylinder, a valve and spray forming mechanism converts a liquid stream expelled from the pump chamber into a spray.

Abstract: A closable dispensing pump for fluid substances comprising a chamber in which a piston is slidable, drivable by a stem, said stem presenting in its interior at least one first passage communicating with said compression chamber and a dispensing pushbutton presenting a second passage opening towards the outside of said dispensing pushbutton. The first passage presents a first aperture which opens onto said first contacting surface, said second passage presenting a second aperture which opens onto said second contacting surface, said pushbutton and said stem being mutually rotatable about a longitudinal axis between at least one open position in which said first and second aperture face each other and are in mutual communication, and a closed position in which they are mutually isolated and displaced.

Abstract: The perfume dispenser (1) includes a container (3) containing a perfume, a device (2) for pumping and atomizing the perfume, a pump and a tube (16) for drawing off the perfume. The first end (18) of the tube is connected to the pump, the second end (20) thereof being arranged in the bottom of the container (3) which includes a region perforable by the tube (16) embodied in the form of a perforation unit.

Abstract: A simplified pump for dispensing fluid substances withdrawn from a container of said substances, comprising a cup-shaped body into which a hollow stem extends, an endpiece of the cup-shaped body, said cup-shaped body presenting a passage, closable by a valve, and a seat for housing one end of a dip tube, a piston, an elastic member and a movable valve for closing the stem cavity, an elongated rod, a first end of which is inserted into and retained in a seat provided at the second end of the cup-shaped body, an intermediate portion of the rod having a cylindrical profile of diameter less than the diameter of the stem cavity into which said rod portion extends, said movable valve for closing the stem cavity comprising a continuous elastic lip projecting from a second end of the rod towards the outside of said cylindrical chamber, said lip being sealedly slidable in contact with the cylindrical surface of the stem cavity.

Abstract: A piston pump is provided in which the piston-chamber forming member has a chamber within which a piston of a piston forming element is coaxially slidable. A locating member is provided on the piston forming element for engagement of the piston-chamber forming member externally of the chamber to assist the piston-chamber forming member and the piston forming element while sliding axially maintaining the piston centered and coaxial relative to the chamber.

Abstract: A dosing device includes a body and an actuating element mounted in non-rotatable, liftable manner on the body. A counting device for the actuating strokes has a rotary counting ring forcibly coupled as a function of a lifting movement of the actuating element. A lock blocks the actuating element following a predetermined number of actuating strokes. The lock is associated with the counting ring in such a way that the latter can perform more than a complete revolution before the actuating element is blocked.

Abstract: A fluid dispenser device (1) for associating with a fluid reservoir (3), the device including at least one check valve (12, 2) that is suitable for controlling the flow of fluid through the device, the check valve comprising a seat (12), and a movable valve member (2) that defines a contact zone that is suitable for bearing against the seat (12) in leaktight manner, the device including resilient prestress means (23) that urge the valve member in leaktight contact against its seat (12) at rest, the device being characterized in that the prestress means (23) are formed integrally with the valve member.

Abstract: A fluid dispenser member designed to be associated with a fluid reservoir having a neck, said member comprising: a body defining at least part of a fluid chamber, said body being provided with fixing means for fixing onto the neck of the reservoir, said body including a fluid inlet connecting the inside of the reservoir to the fluid chamber; a pusher mounted on the body in such a manner as to be displaced axially between a rest position and a driven-in position; and a spring urging the pusher into the rest position, wherein the spring is housed entirely inside the pusher, and the body is made of a transparent or translucent material.

Abstract: A valve mechanism for a pressure chamber, particularly a pumping device, includes a tappet and a valve disk, in which the valve disk is attached to the tappet. The valve disk is provided on the tappet so as to be movable in relative manner between a starting and an end position.

Abstract: A piston pump dispenser having a reciprocating piston pump arrangement which, in a dispensing stroke, dispenses fluid from an outlet and, in a charging stroke, to draw fluid from a reservoir also draws back fluid from the outlet through which fluid is dispensed in the dispensing stroke.

Abstract: A dispenser has a housing, and a variable-volume storage chamber formed within the housing and defining a substantially fluid-tight seal between the chamber and exterior of the housing for storing a substance to be dispensed. A piston is mounted within the housing, and a one-way valve is mounted within the housing and coupled in fluid communication with the variable-volume storage chamber.

Abstract: A structure for a green nozzle includes a, pressing body, a spring, a fixing cover, a piston, a connecting rod, a switch valve and a cylinder. The output tube of the pressing body inserted into the spring, the fixing cover, and the piston is connected to the connecting rod. The spring is installed inside the round dented surface located at the upper part of the fixing cover. The switch valve is inserted into the connecting rod from the lower part such that the cylinder is located at the inner lower part of the fixing cover and is further connected to a straw and installed inside a container. The fixing cover is installed at the opening of the container. Liquids such as lotion or perfume inside the container will not get in contact with the spring of metallic material. Thus, chemical change will not happen, and environmental issues can be ignored. In addition, a simplest assembly can be used to reach the function of ejection of the liquid.

Abstract: The embodiment of the invention are directed to a dispenser assembly having a reservoir bottle with an opening for fluid communication. The opening is formed to receive a housing cap and a dispensing pump such that the dispensing pump is sealingly engaged to the bottle opening. The housing cap has an outer surface in contact with the reservoir opening and an inner surface in contact with the dispensing pump. The outer surface includes a lip which engages the reservoir opening and a step which engages the pump.

Abstract: An atomizer provided with a manually activated pump forming a stopper, which is mounted by force in the opening of the bottle. The bottle is made entirely from a plastic material, moulded as a single piece, and the opening of this bottle comprises on the inside an annular hooking rib and the plastic material used to make the bottle is harder and more rigid than the material used to make the pump body so that the said rib can encrust in the pump body.

Abstract: A pump for delivery of gas-liquid mixtures adapted to be connected to a container for a liquid comprising: suction means adapted to be reciprocated between a first rest position and a second position so as to collect the liquid from the container; a mixing chamber in communication with the suction means so that when the suction means are moved from a first position to a second position, the liquid is collected from the container and conveyed into a mixing chamber; elastic means adapted to displace the suction means back in the first position after that the suction means are moved from a first position to a second position. The elastic means define a variable volume gas chamber in communication with the mixing chamber so that, when the suction means are moved from a first position to a second position, the gas is conveyed into the mixing chamber and a gas-liquid mixture is formed in the mixing chamber.

Abstract: A fluid dispenser device including a body (1), a reservoir unit (3) having a reservoir containing one dose or two half-doses of fluid, a dispensing member mounted to move axially inside the reservoir (3) between a rest position and a dispensing position, and an actuating element (5) that is mounted to move between a rest position and an actuating position. The actuating element (5) is disposed laterally, and has an end portion provided with a cam surface (6) which co-operates with the dispensing member (8) or the reservoir unit (3), the actuating element (5) being moved in a direction that is different from, and in particular substantially perpendicular to, the axial direction in which the dispensing member (8) moves relative to the reservoir.

Abstract: The decorative air gap cover includes a base cover and a decorative attachment. The base cover includes a cup body and a cover fastener on a top thereof. The decorative attachment includes a decorative body and a decorative fastener on a bottom thereof. The cover fastener and the decorative fastener mate with each other to allow the decorative attachment to be retained on a top of the base cover. A liquid dispenser air gap cover includes the base cover and a liquid dispenser attachment. The liquid dispenser attachment includes a liquid container, a liquid pump and a liquid fastener on a bottom of the liquid container. The cover fastener of the base cover and the liquid fastener mate with each other to secure the liquid dispenser to a top of the base cover.

Abstract: A fluid dispenser assembly having a fluid dispenser (1) and a wrapper (2) at least partly encasing the dispenser. The wrapper defines at least one application zone (21, 26) that comes into contact with the dispenser. The dispenser includes a body (10) forming at least one substantially cylindrical segment that defines an affixing zone for coming into contact with the application zone of the wrapper.

Abstract: The invention relates to a dosing device that comprises a medium reservoir (S) and a pump device for dosing and dispensing a medium stored in said medium reservoir. The pump device is associated with a pump chamber, and with at least one inlet and one outlet valve. According to the invention, the inlet valve is configured as a sliding valve (10, 12) which, in its closed position, can be displaced by a dosing stroke that defines a dosing volume for the pump chamber (17). The invention further relates to the use of said dosing device for dispensing pharmaceutical active substances, especially for nasal administration.

Abstract: A fluid dispenser member having a dispensing wall (623) defining an outside surface and inside surface, said wall being provided with a through dispensing orifice (625) connecting the inside surface to the outside surface, the inside surface forming a leaktight slide cylinder for a piston (632, 633) suitable for moving in leaktight contact inside said cylinder for selectively unmasking the dispensing orifice, said piston forming a wall element of a fluid chamber inside which fluid is selectively put under pressure, said fluid dispenser member being characterized in that the inside surface extends over two surface segments, namely a top segment (6232) and a bottom segment (6242), the top segment having an inside diameter that is smaller than the inside diameter of the bottom segment, the dispensing orifice being formed at the top segment, and the piston being provided with a sealing lip (633) in leaktight sliding contact with the bottom segment.

Abstract: A manually actuated pump sprayer adapted to be mounted on a container of liquid to be sprayed upon pump actuation is provided, and includes a plunger head having a side wall containing a discharge orifice. The plunger head may be reciprocable relative to the pump sprayer. An overcap may be independently rotatably disposed on the plunger head, and include a side wall overlying the discharge orifice in a condition of non-use. The side wall may include an opening disposable in alignment with the discharge orifice upon rotation of the overcap relative to the plunger head. A container closure may be provided for affixing the plunger head and the overcap relative to the container. The plunger head may be axially reciprocable relative to the container closure and may otherwise be locked relative to the container closure when in first and second orientations.

Abstract: A fluid dispenser device having a fluid reservoir (10), a pump (20) mounted on the reservoir (10) for selectively dispensing the fluid, and a dispenser head (30) connected to the pump and incorporating a dispenser orifice (31). The device includes at least two laterally-actuated elements (40, 50) distributed around the dispenser head (30), the laterally-actuated elements (40, 50) being displaced simultaneously in a direction that is approximately transverse to the central axis of the device, and each co-operating with a peripheral edge (11) of the reservoir (10) so as to exert an axial force thereon.

Abstract: A fluid dispenser having a substantially rigid shell (1) provided with an opening (14), a flexible pouch (23) fixed to a pouch support (2) forming a fixing bushing (22) defining an outlet passageway (24) for the fluid, and a dispensing member (3) such as a pump for extracting the fluid from the flexible pouch through the outlet passageway of the pouch support; and wherein the fixing bushing (22) of the flexible support (2) is fixed in the opening (14) of the shell (1).

Abstract: An inexpensive, readily visible indicator for liquid levels in a vacuum bottle that includes a coating of reflective material to minimize radiation heat transfer from the interior of the vacuum bottle to the exterior of the assembly. The vacuum bottle assembly includes a container receiving the vacuum bottle and a transparent or translucent window is located in the side wall of the container and in alignment with an interruption in the reflective coating. An indicator is located within the vacuum bottle and is aligned with both the windows and the interruption so as to be visible therethrough to provide an indication of the level of the liquid contained within the inner liner of the vacuum bottle.

Abstract: A foam forming unit particularly suitable for a liquid container, comprising a pump for liquid and a pump for air, which are each provided with an inlet and an outlet, the foam forming unit further comprising a mixing chamber which is in communication with the outlet of each pump, a dispensing part provided with an outflow channel with a foam opening, the channel being in communication with the mixing chamber, and valves in respectively the inlet and the outlet of each pump for drawing in respectively delivering air and liquid, wherein one or more valves are formed integrally with the air pump or liquid pump into a single construction element.

Abstract: A liquid soap container comprising of a dispensing pump which incorporates a pressurised air freshener canister or a liquid air freshener container. When a dispensing pump is depressed it also activates the valve of a pressurised air freshener canister or a pump for a liquid air freshener container to refresh the air whilst at the same time dispensing the liquid or gel soap. After the action of depressing the pump has stopped the release of the air freshener also stops. Both systems work simultaneously. An air vent casing helps secure the air freshener canister or the liquid air freshener container, and also temporarily contains the released air freshener before it vaporises or evaporates in to the atmosphere.

Abstract: The disclosure concerns packaging and dispensing of fluid products. The disclosed device comprises at least two sealed flexible bags arranged in a single common rigid container, associated with at least a pump or valve, actuated by an actuator, wherein the bags cooperate with at least a ring for being fixed to the container and with the pumps or valves. The device is designed to dispense fluids separately or mixed.

Abstract: A plastic lined metallic liquid soap dispenser (20) is formed consisting of a hollow metallic bottle (22) having a threaded neck, (24) and a plurality of separate metallic parts such as a bottom (26). A discrete plastic insert (38) is disposed within the hollow of the bottle (22), for isolating the metallic bottle from liquid soap stored within the dispenser to preclude a chemical reaction and/or contamination thereof if the metallic bottle is in intimate contact with liquid soap or the like. Connection means, in the form of threads or the like, join the bottle separate parts together around the plastic insert. Bottle access and closure means, including a hand pump (44), are attached to the threaded neck permitting the liquid within the plastic insert to be easily dispensed and to enclose the liquid for storage when not required for use.

Abstract: A manually operated vertically reciprocated pump dispenser has a simplified construction with two separate pumps that pump two separate liquids from a container and keep the two separate liquids separated from each other as they are pumped through the dispenser, mixing the liquids for the first time in a discharge passage of the dispenser just prior to the mixed liquids being discharged from the dispenser.

Abstract: A fluid discharge pump comprises: an outer cover connected to an upper portion of the fluid-storing portion; a nozzle head provided with a fluid discharge nozzle; a bellows member disposed between the fluid-storing portion and the nozzle head; a first valve mechanism for inflow coupled with a lower end of the bellows member; a second valve mechanism for outflow coupled with an upper end of the bellows member; and a third valve mechanism for anti-leakage disposed between the nozzle and the second valve mechanism inside the nozzle head.

Abstract: A manually operable pump for dispensing creamy substances from a container on which the pump is mounted, and for preventing emergence or leakage of creamy substances along the outer surface of the pump stem when the pump is at rest and the container on which it is mounted is inclined to the upright position, with the pump at least partly immersed in the creamy substances. The pump comprises two separate seal regions provided between the pump main body and the piston and respectively the stem of the same pump.

Abstract: A fluid-storing container includes a fluid-dispensing pump 1 having an inflow valve mechanism 4, an outflow valve mechanism 5, a bellows member 6 and a leakage prevention member 101, a nozzle head 2, and a fluid-storing portion 3. The leakage prevention member 101 is disposed at the lower end of a coupling member 102 and allows a fluid to pass through only when the bellows member 6 deforms.

Abstract: A dispenser for dispensing metered amounts of liquid or paste-like products has a cylindrical reservoir having an open bottom and an upper end with an intake valve. A plunger is arranged axially movably in the cylindrical reservoir and closes off the open bottom of the cylindrical reservoir. A dispensing head is arranged on the upper end of the reservoir. The dispensing head has a bell-shaped dispensing pump having elastic sidewalls and a pump head with a through opening having an outlet valve. The dispensing pump together with the intake valve and the outlet valve delimits a closed pump chamber. The outlet valve is manufactured as a monolithic part of the pump neck such that with a simple working step the entire through opening of the pump neck is closable by a valve flap of the outlet valve.

Abstract: A liquid-candy dispenser having a container and an extendable and rotatable dispensing nozzle sprayer that is adapted to be moved in multi-directions for fun and to permit better dispensing of the candy in children's mouths. The extendable and rotatable dispensing nozzle sprayer has a finger-actuated spray head to activate a fluid pumping unit. The sprayer also includes an elongated tube having one free end adapted to rotate 360° in a Y-plane with respect to and in fluid communication with the finger-actuated spray head. A dispensing nozzle is affixed to the other free end of the elongated tube.

Abstract: A liquid discharge pump possesses a resinous bellows material 6, a resinous inflow valve mechanism 4, a resinous outflow valve mechanism 5, a first pressing portion 11 which moves a valve portion in the outflow valve mechanism 5 to open the inflow valve mechanism when a nozzle head 2 is pressed, and a second pressing portion 12 which presses the bellows material 6 from a stretched position to a folded-up position when the nozzle head 2 is pressed.

Abstract: A fluid dispenser device designed to be mounted on the neck of a receptacle, said device comprising a dispensing member (1), such as a pump or a valve, and fixing means (2) for fixing the dispensing member to the neck of the receptacle, said dispensing member comprising a body (10) whose top end is provided with a collar (12) that projects outwards, said fluid dispenser device being characterized in that the fixing means comprise a substantially cylindrical ring (20) engaged on the body (10) under the collar, said ring (20) being in peripheral leaktight contact with the body by being radially clamped thereon.

Abstract: A dosage pump which includes a pump body and a control means with rest and distribution positions. The control means includes a dosing chamber, a return spring, and a member to ensure friction braking of the sliding movement of the actuating members of the pump.

Abstract: A vegetation care vessel for facilitating the care of plants and other vegetation. A hollow body includes a top portion, a planar bottom portion and a continuous wall portion. A spout communicates with the interior of the hollow body. An inwardly-projecting region is provided in the wall for receiving a dispenser having a compressor-spout. An aperture is arranged in the top portion of the body for admitting liquid from the compressor-spout into the interior of the hollow body.

Abstract: The disclosure provides a fluid-tight, but non-releasable or only under a large force releasable connection between the delivery device of a dispenser and the medium reservoir of the dispenser. For the discharge of a fluid, preferably liquid medium, which can in particular contain a pharmaceutical substance, such a dispenser has at least two parts, firstly a medium container for storing the medium and secondly a delivery device fastenable to the medium container. For fastening together the medium container and the delivery device, fastening portions are formed on both parts. In the fastening portion there is a gap between the medium container and the delivery device. An elastically deformable ring fastener, preferably as a layer on the outside of the delivery device, is provided and its wall thickness, prior to installation, is larger than the gap dimension.

Abstract: One preferred embodiment of the present invention is directed to a convenient and efficient dispenser that includes at least one container and at least one nozzle for dispersing the contents of the container(s). In one preferred embodiment, first and second nozzles functionally associated with sterilization agent within the container are positioned to disperse the sterilization agent to first and second target points respectively, the first target point being distinct from the second target point. In another preferred embodiment of the present invention, a grid is positioned in front of the nozzle(s) so that a dispersement of sterilization agent from within the container(s) sterilizes the grid(s) when the nozzle(s) are activated. Yet another preferred embodiment of the present invention is directed to a multiple-mist dispenser that includes a dual chamber activation sleeve so that two nozzles are simultaneously actuable by depression of the dual chamber activation sleeve.

Abstract: The invention provides a pump of type comprising a moving member mounted to move relative to a support, the moving member having a central duct into which the substance to be dispensed penetrates via at least one opening, the support co-operating with the moving member to define a variable volume pump chamber around said central duct, the pump also having a diaphragm having a central portion in the form of a sleeve that is open at its top end and closed at its bottom end, said central duct being inserted in said central portion, the diaphragm being organized in such a manlier as to isolate the opening(s) of the pump chamber when the volume of the pump chamber increases and the substance is sucked into it. The bottom portion of the central portion of the diaphragm presents, at least over a sector of its periphery, a preferred deformation zone.