WO2008113941A1 - Spring for a fluid product dispensing member - Google Patents

Abstract

The invention relates to a spring (6) for a fluid product dispensing member such as a pump or a valve, wherein wire-drawing soap and/or a residue thereof is present on the surface of said spring, characterised in that a polyparaxylene coating is applied on the spring in order to cover the wire-drawing soap and/or the residue thereof so that the polyparaxylene coating prevents any contact between the soap and the fluid product.

Description

 Fluid dispenser member spring

The present invention relates to a constituent element of a fluid dispenser member, such as a pump or a valve, and more particularly a spring. This type of dispensing member is frequently used in the fields of cosmetics, perfumery or even pharmacy to make fluid dispensers.

In addition to the constituent element, the invention also relates to a dispensing member and a fluid dispenser. The present invention is however limited to only pumps and valves, but can also be applied to all types of dispensing members for dispensing a fluid product, liquid or powder, from a fluid reservoir.

Conventionally, the fluid dispenser member comprises a plurality of constituent elements that are made separately and then assembled to form the dispensing member. In general, most of the constituent elements are made of plastic material, for example by injection / molding. Certain constituent elements may also be made of metal, such as the return spring and / or precompression. The dispensing member generally comprises a body which is intended to be fixedly mounted in an opening of a fluid reservoir. For this, one can use all types of attachment means, snap, screw or crimp. The inlet of the dispensing member formed at the lower part of the body is conventionally provided with a non-return valve which selectively closes the inlet of the dispensing member. The dispensing member also comprises a piston which is intended to slide in a sealed manner inside a sliding shaft generally formed by the body. To move this piston, the dispensing member generally comprises an actuating rod surmounted by a pusher on which the user can press to move the actuating rod and thus the piston. To bring the piston and the actuating rod towards their rest position, the dispenser member generally comprises a return spring. The actuating rod is thus pushed back to the rest position by the spring against another constituent element of the dispensing organ which is often referred to as "ferrule".

Thus, in a dispensing member such as a pump or a valve, there are several constituent elements whose choice of materials requires taking into account both mechanical (structural sensitivity, impact) and physicochemical (thermal shock, permeability to water vapor and gas) as organoleptic constraints (loss of aroma, water, taste) and compatibility with the product to be distributed (container / content migration). As well as the choice of materials, their manufacturing processes are also to be considered, as they may leave residues incompatible or likely to react with the product to be distributed.

Indeed, problems of coloring and / or corrosion have been highlighted concerning the springs of dispensing members in contact with perfumes and cosmetics. Studies have identified the cause of these problems, namely the reaction of wire drawing soap and / or their residues, remaining on the surface of the spring, with the perfume or the cosmetic product. The wire drawing makes it possible to obtain metal wires, such as spring wire, of well-defined section and shape. It is a transformation process of passing a metal bar, in this case a spring steel rod, through a calibrated orifice, called "die", under the action of a continuous thrust. Wire drawing soaps, used as lubricants in the die, leave residues and / or residues on the surface of the spring wire, which may subsequently react with the product to which the spring will be exposed. Or it often proves difficult, if not impossible to completely remove the manufacturing residues by cleaning or pickling of these constituent elements of distribution members, especially since they are already shaped in their final configuration. , for example already wound in spring.

A first object of the present invention is to overcome the aforementioned drawbacks by providing dispenser springs free of harmful surface materials that can interact with the product to be dispensed. The present invention also aims to ensure that the surface of springs of dispensing members is inert and resistant to fluid products, such as perfumes, cosmetics and pharmaceuticals, and this regardless of the method of implementation of materials that form the constituent elements of the dispensing member.

Another object of the present invention is to provide reliable and compatible springs of dispensing members obtained by a simple and economical method, which method is easily adaptable to the constituent elements of existing dispensing members, whatever the shape of the surfaces. of these constituent elements, including sharp angles and narrow or deep cavities, and which on the other hand does not entail a change in the appearance of these elements.

The present invention also aims to provide a fluid dispenser that keeps intact the appearance and physical, chemical, and organoleptic properties of the product to be dispensed.

The present invention more generally aims to modify the physical, mechanical, chemical or aesthetic properties of these springs to make them more compatible with a particular use.

To achieve this object, the present invention provides a spring of a fluid dispenser member such as a pump or a valve, drawing soap and / or a residue thereof being present on the surface of the spring, characterized in that a poly-para-xylene coating is applied to the spring, thereby covering the wire drawing soap and / or its residue, so that the poly-para-xylene coating prevents contact between the soap and the fluid product. This surface coating thus fulfills a barrier or protection function (inertia with respect to another material).

Advantageously, the appearance of the coated element is identical to that of the uncoated element.

The invention also relates to a fluid dispenser member, such as a pump or a valve, comprising at least one spring covered with a coating as defined above. The invention also defines a fluid dispenser comprising a fluid reservoir and a dispenser member comprising at least one such spring.

The invention will now be further described with reference to the attached single figure which gives, by way of non-limiting example, an embodiment of the invention. This single figure shows in vertical cross section a fluid dispenser member made according to the invention.

The dispensing member shown in the single figure comprises several constituent elements, namely a body 1, an actuating rod 2, a piston 3, a shell 4, an inlet valve 5, a return spring and precompression 6 and a pusher 7. The dispensing member is here a pump with or without air intake and its constituent elements are designed accordingly. Instead of this pump, the present invention can also be applied to a valve, or to another type of dispensing member for dispensing a fluid product from a fluid reservoir. All the constituent elements of the dispenser member may be made of plastic material, including the return spring, or any other suitable material. In the example shown in the single figure, the return spring 6 is made of metal in the form of a coil spring.

The body 1 is in the form of a hollow tube which flares from its lower end to its upper end. The flaring of the body is carried out in a staged way. At its upper end, the body defines a retaining flange 11 which serves to fix the pump body in a fixing ring (not shown) which is fixedly mounted on an opening of a reservoir. At its lower end, the body 1 defines an inlet 12 which is intended to communicate with the interior of the fluid reservoir. The inlet 12 may optionally be provided with a dip tube (not shown). Above the inlet 12, the body forms a seat 13 for an inlet valve 5. This valve 5 is here made of plastic material and comprises a sealing flange 51 intended to come into sealed contact with the seat 13 1. To limit the valve stroke, this one form an anchor foot 52 which extends through a constriction 14 formed between the inlet 12 and the seat 13. The valve 5 is thus trapped in the constriction 14 while being able to move on a limited axial stroke. During its axial displacement, the foot 52 of the valve 5 slides unsealed in the constriction 14. Friction or sliding forces are thus generated at this location.

The actuating rod 2 is here made in two parts, namely an upper part 20 and a lower part 24. These two parts are connected to each other in a fixed and definitive manner. The upper part 20 is substantially tubular and the lower part 24 comprises a pin 27 engaged inside the upper part 20. However, a passage 271 is defined around the spindle 27. This passage 271 communicates with an internal channel 201 formed by a conduit 21 at the upper part of the part 20. On the other hand, the upper part 20 forms a shoulder 22 whose function will be given below. The lower part 24 defines a ring 26 which serves as an outlet valve seat. The upper part 20 also defines a frustoconical surface 223 whose function will be given below.

The piston 3 comprises a cylindrical sleeve 33 engaged around the lower part of the upper part 20. The piston 3 also comprises an outer piston lip 31 in leaktight sliding contact inside a sliding shaft formed by a wall 1. The piston 3 also defines an inner outlet valve lip 32 intended to come into sealing contact with the ring 26 which serves as an outlet valve seat. The piston 3 is slidably mounted on the actuating rod 2. More precisely, the sleeve 33 of the piston 3 can slide axially on the lower part of the upper piece 20 so as to disengage the inner lip 32 from its sealing contact with the 26. A passage is thus established allowing the fluid to flow through the passage 271 and the internal channel 201. When the piston 3 is urged upwards, thus opening the outlet valve, the upper part of the sleeve 33 s engages on the frustoconical surface 223 formed by the actuating rod 2. The engagement of the sleeve 33 on frustoconical surface 223 is a function of the pressure prevailing inside the pump chamber. Indeed, the inlet valve 5, the body 1, the lower part 24 and the piston 3 together form a pump chamber 10 in which the fluid can be selectively pressurized. The actuating rod 2 and its trapped piston 3 are biased in the rest position, shown in the single figure, by the return and pre-compression spring 6. This spring bears on the one hand on the body 1 and on the other on the lower part 24. The rest position is reached when the piston 3 comes into abutting contact against the lower end of a shell 4 which is engaged by force in the open upper end of the body 1. This shell 4 also forms a shoulder 41 which extends radially inwardly. The function of the shell 4 is a function of closing or closing the pump, ensuring that the spring 6, the piston 3 and the actuating rod are held inside the body 1. Only the conduit 21 of the part upper 20 of the actuating rod extends out of the shell 4 to be capped by a pusher 7, preferably provided with a nozzle 71 forming a spray orifice

72. This is a conventional design for a pump of the prior art.

According to the invention, the spring 6 of the dispenser member is covered with a surface coating forming an extremely thin layer of an advantageously inert material. This layer protects the surface of the spring and constitutes a barrier which eliminates any possibility of contact between the spring surface of the element and the product, and more particularly between the wire drawing soap and / or residues or residues thereof and the fluid product, such as perfume.

The inert coating material of the invention is polyparaxylene (Parylene®). The latter is already used in the medical sector as a waterproof and biocompatible material, particularly as a coating for the electronics of hearing aids, for hypodermic needles, or for cardiac simulators. The Parylene® treatment process is well known and carried out in several steps. The first step consists of a vaporization of a di-para-xylene (dimer) powder. This step takes place at a temperature of about 150 ^° C. The second step is a pyrolysis step which is carried out at a temperature of about 680 ^° C. The dimer is cleaved into two divalent monomers (paraxylene) gaseous reactants. The last step is that of vacuum deposition at about 25 ° C where the monomers polymerize on the substrate forming poly (para-xylene)).

The polymer coating of Parylene® has a colorless and transparent appearance. Gas phase deposition allows Parylene® to penetrate everywhere and cover all surfaces without creating bridges between adjacent surfaces. A regular coating on all surfaces is obtained, including sharp angles and cavities narrow, deep or difficult to access. The thickness of the deposit can be controlled and adjusted from 1 micron to 30 microns or more.

The use of a coating of Parylene® on the springs of fluid dispensing members is therefore particularly advantageous because of all these properties. In particular, the Parylene® deposited on a dispenser member return spring creates a protective envelope of the spring and prevents the reaction between the remaining drawing soap residues on the spring and the perfume or cosmetic product.

Conventionally, the springs undergo a stripping step, which is however imprecise and unreliable. This stripping is supposed to remove unavoidable manufacturing residues remaining on the surface of the springs, but this is unfortunately not always the case. Sometimes residues remain. The coating of the present invention makes it possible to complete or replace this pickling step with a precise, reliable and hitherto unexplored processing method in the type of application of the present invention.

According to the present invention, the use of a barrier coating comprising Parylene® on the springs of a dispensing member thus makes it possible to keep intact the organoleptic properties of the product to be dispensed.

Claims

claims 1.- Spring (6) of a fluid dispenser member such as a pump or a valve, drawing soap and / or a residue thereof being present on the surface of the spring, characterized in that a poly-para-xylene coating is applied to the spring, thus covering the wire drawing soap and / or its residue, so that the poly-para-xylene coating avoids contact between the soap and the fluid product. 2. A spring according to claim 1, wherein its appearance is identical to that of an uncoated spring. 3.- fluid product dispensing member, such as a pump or a valve, comprising at least one spring according to any one of the preceding claims. 4. A fluid dispenser comprising a fluid reservoir and a dispensing member according to claim 3.