FR3033269A1 - SPRAY HEAD AND METHOD OF MANUFACTURING SUCH HEAD - Google Patents

Abstract

The invention relates to a vaporizer head (1), comprising a push button (2) comprising a pressurized fluid distribution circuit comprising a collector adapted to cooperate with a dispensing valve of said fluid, at least one channel (12) d supply unit connecting the collector to a stirring chamber (11) and a spray orifice (21), characterized in that the push button comprises a body (3) on which is hinged a cover (4), the body and the lid being molded in one piece in a first synthetic material, said cover, in the closed position, forming with said body said chamber (11) stirring. An overmolded yoke (25) ensures the integrity of the push button and imparts aesthetic and / or sensory characteristics to the spray head. The invention also relates to a method of manufacturing such a vaporizer head.

Description

The invention relates to a vaporizer head, of the type used to deliver fluid products under pressure. The invention also relates to a method of manufacturing such a vaporizer head. In many fields, for example cosmetics, cleaning products, etc. fluids (liquids, gases) or pulverulent materials which are fine enough to be assimilated to fluids, pressurized in containers and dispensed by pressing a spray head are used. A spray head has a push button operated by the user's finger to open a sample valve and allow the compressed fluid to escape through a spray port. The push button can be fitted on a sampling tube fixed on the pressure vessel and acting on the sampling valve or comprise a tubular portion adapted to act directly on the valve. The container can be pressurized by a repeated action on a pump actuated by the push button or be initially loaded by a fluid under pressure, either the fluid to be dispensed or a separate propellant. For some products, it may be necessary, in order to create a uniform vaporization mist, to place a cavity, called a stirring chamber, in the fluid path just upstream of the spray orifice. It is known, for example from the document BE 762113, a monobloc vaporizer head obtained by molding a thermoplastic synthetic material. However, to make one or more stirring chambers, a molding core is used in the form of a rod of a diameter corresponding to the spray orifice on which at least one bulge is disposed. After injection of the molding material into the mold and solidification thereof, the rod is removed in force by taking advantage of the elasticity of the still hot material. This embodiment, however, has several disadvantages. The diameter of the rod must be small enough to achieve a spray orifice of a few tenths of a millimeter in diameter, but the rod must withstand a significant tensile force to extract the bulges it bears against the elasticity of the material. In addition, the sequencing of the molding and the extraction of the rod must be very precise so that this extraction is done at a precise moment of the cooling of the material, when it already has its final shape but is still elastic enough to resume this shape despite the passage of bulges, without enlarging the spray orifice. Given the above disadvantages, another embodiment has been proposed, described for example in the document FR1355350. The vaporizer head is then made in two parts, a molded body of thermoplastic synthetic material in which is formed a substantially cylindrical cavity within which a cylindrical nozzle molded separately is inserted in force. The nozzle has a central duct opening on one side to the outside of the vaporizer head (when the nozzle is mounted in the body cavity) to form the spray orifice and on the other side in a spray chamber. agitation formed between the nozzle and the bottom of the body cavity. This embodiment has the disadvantage of using two separate parts that must be made separately and then assembled with precision. At least three workstations are required for producing such a spray head, which increases the cost of manufacture. In addition, depending on the materials used and manufacturing tolerances, it is possible for the nozzle to separate from the body, rendering the spray head unusable. The invention therefore aims to provide a vaporizer head which does not have the disadvantages of the prior art.

The invention also aims to provide such a vaporizer head that is economical to manufacture. The invention aims to provide such a spray head that can be manufactured in large series and at high speed with a minimum of manual operations.

The invention also relates to a vaporizer head which makes it possible to respect improved tolerances and increased performance. The invention further provides a vaporizer head that has improved sensory and / or aesthetic characteristics.

The invention further relates to a method of manufacturing such a spray head by injection of a synthetic material which is easy to implement. The invention also relates to a method of manufacturing such a vaporizer head which requires a number of reduced injection operations.

To do this, the invention relates to a vaporizer head, comprising a push button comprising a pressurized fluid distribution circuit comprising a collector adapted to cooperate with a dispensing valve of said fluid, at least one supply channel connecting the a collector with a stirring chamber and a spray orifice, characterized in that the pusher button comprises a body on which is hinged a cover, the body and the cover being molded in one piece in a first thermoplastic synthetic material, said lid, in the closed position, forming with the body said stirring chamber. Thus using a push button in two molded parts together and simultaneously forming the body and the lid connected by a flexible hinge tongue, a stirring chamber can be obtained as well as other elements such as feed channels. etc. presenting a wide variety of shapes and therefore performance when the lid is folded over the body. In addition, the body and the cover being obtained simultaneously, from the same material, the tolerances of each of these two parts are automatically matched and allow to reach a high accuracy, a guarantee of a good reliability of the head of spray. In addition, the body and the lid being integral with each other, the possible operations of assembly and management of several references are simplified.

Advantageously and according to the invention, in a first embodiment, the lid and the body each comprise a hollow recess forming when the lid is folded down on the body, the stirring chamber and the spray orifice as well as at least one supply channel connecting the stirring chamber to the collector. Thus, the stirring chamber, the feed channel and / or the spray orifice are made "in the open", which allows for the realization of internal shapes, such as for example a feeding channel opening at angles various in the agitation chamber or turbine blades in the latter, to enhance the swirling motion of the fluid. Advantageously and according to the invention, each imprint forms a distinct feed channel, the feed channels being symmetrical with respect to a contact plane between the body and the cover in the vicinity of the stirring chamber and placed on either side. else of this one. Thanks to these two supply channels which open into the stirring chamber substantially opposite one another but offset with respect to the contact plane between the body and the cover, the supply of the chamber of agitation by the fluid under pressure causes a swirling motion in the chamber, promoting the vaporization in fine droplets at the outlet of the discharge orifice.

Advantageously and according to the invention, in a second embodiment, the body comprises a feed channel opening into a recess formed on the periphery of the body, said recess being closed by an end plate integral with the lid, bearing the spray port, and providing a space forming the agitation chamber between said recess and said plate. In this embodiment, the lid is folded over the supply channel formed in the body so as to form a conduit which opens into a space between the bottom of the recess of the body and the end plate of the lid. The periphery of this end plate is adapted to close the recess, thus providing a stirring chamber of predetermined depth in a plane orthogonal to that of the cover. The flow of fluid under pressure thus abruptly changes direction between the feed channel and the stirring chamber. In addition, the axis of the spray orifice is orthogonal to the plane of the stirring chamber, further improving the vaporization of the fluid. Advantageously and according to the invention, the recess 5 comprises reliefs, said reliefs of agitation, bearing on the end plate. To further improve the vaporization of the fluid, reliefs in the form of arcs abutting against the end plate form channels generating a swirling motion in the plane of the stirring chamber. Advantageously and according to the invention, the body and the lid 10 comprise positioning and hooking means cooperating with each other to keep the lid folded over the body. Whatever the embodiment of the invention, it is important that the lid is folded into a precise position on the body and held in this position. To this end, various positioning and locking means are provided such as centering pins molded on the upper face of the body cooperating with centering holes formed in the cover. An appropriate form of the flanks of the centering pins (beads, against draft etc.) allows the latch in the folded position of the cover on the body. Other forms may be provided for these means, for example latches molded in relief on the cover cooperating with molded hollow snares in the body. Advantageously and according to the invention, the push button, lid folded over the body, is coated with an overmolded cap having an opening facing the spray orifice of the push button. In order to perfect the tightness of the vaporizer head, the pushbutton in the closed lid position is covered with an overmolded cap making it possible to hold the lid in position and to seal it except for the orifice spray. In addition, the overmolded coping provides aesthetic and sensory functions (such as surface conditions, sensations of touch) varied.

Advantageously and according to the invention, at least one of the lid and the body comprises reflow fins, adapted to weld the lid on the body during overmolding of the yoke. The lid and / or the body have projecting fine ridges provided for crashing on a facing surface of the body and / or the lid when the lid is folded down. Thanks to the temperature rise due to the over-molding of the yoke and the reduced size of these fins, the latter melt and weld the cover and the body between them. The invention also extends to a method of manufacturing a spray head made of synthetic material characterized in that: - a first thermoplastic synthetic material is injected into a mold adapted to form a body and a lid of a push button, the body and the lid being secured by a tongue of material adapted to form a hinge between the body and the lid, - the lid is folded on the body, 15 - one overmould a clevis on the push button with a second material synthetic thermoplastic so as to make the body and the lid integral. Thanks to this process which comprises only three easily automatable operations, it is possible to obtain a complete vaporizer head in a reduced time. In particular, the first two operations use techniques known under the name of "capsule service" usually used to make vial closure devices comprising a body attached to the bottle and a hinged lid adapted to plug an orifice of this body. However, these techniques have never been associated with a step of overmolding a screed which has the effect of definitively immobilizing the body and the lid. Advantageously and according to the invention, use is made of a two-position mold, adapted to: - form the body and the cover in an open position in a first position, - close the lid on the body during a transition between the first position and a second position, - overmoulding the yoke on the push button in said second position. By using a two-position mold, for example coupled to two injection heads, it is possible to simultaneously mold the body and the lid in a first position and the overmoulding of a clevis on a complete push-button in a second position. A cam device associated with the mold allows the lid to be closed and locked on the body during the transition (rotation if it is a rotating mold) between the first and the second position. As a result, a continuous production, practically without human intervention and at a high rate is possible. Advantageously and according to the invention, the overmolding of the screed is carried out with a thermoplastic synthetic material which is distinct from the first material adapted to confer predetermined sensory and / or aesthetic characteristics on the vaporizer head. For the third operation of the process, a second thermoplastic synthetic material is chosen whose melting temperature is of the same order of magnitude or slightly higher than that of the first material used for molding the body and the lid so as to allow the fusion of the reflow fins thus making the body and lid integral. However, this second material may advantageously be chosen because of the appearance that it can impart to the spray head, for example a color or a pearlescent or metallic appearance obtained by adding a dye and / or a filler, metal powder by example, to the synthetic material. Similarly, an elastic material capable of imparting a soft or silky feel to the spray head may be selected. The invention also relates to a vaporizer head and its method of manufacture characterized in combination by all or some of the characteristics mentioned above or below.

Other objects, features and advantages of the invention will become apparent from the following description and the accompanying drawings in which: - Figure 1 shows a sectional view of a push button 5 according to a first embodiment of the invention, cover in open position; - Figure 2 is a perspective view of the lid open push button according to the first embodiment of the invention; - Figure 3 shows a sectional view of a push button according to a second embodiment of the invention, lid in the open position; - Figure 4 is a perspective view of a push button, cover in the open position according to the second embodiment of the invention; FIG. 5 shows a sectional view of a vaporizer head according to the first embodiment, by a vertical plane passing through the spray orifice; - Figure 6 shows a sectional view of a vaporizer head according to the second embodiment, a vertical plane passing through the spray orifice. In the present text, terms such as vertical, horizontal, high, low, high, lower, etc. are used. Referring to a standard position of a push button in the use position on a spray bottle having a vertical axis of maneuvering the valve. A sagittal axis of the pushbutton is also defined as being the axis through which pressurized fluid is ejected when the valve is operated. In the standard position of the push button, the operation thereof is from top to bottom along a vertical axis and the sagittal axis of the push button is substantially orthogonal to the vertical axis. Figure 1 shows a sectional view of a push button 2 by a median plane containing the vertical axis and the sagittal axis. The pushbutton 2 comprises a body 3 connected to a cover 4 by a hinge 5 in the form of a flexible tongue. The push button 2 is obtained by molding a first synthetic material, preferably a thermoplastic material. The body 3, the cover 4 and the tongue forming the hinge 5 are molded simultaneously in this first material. The body 3 is in the example illustrated in Figure 2 in a substantially cylindrical or frustoconical shape. However, the push button 2 could be parallelepipedal, cubic or even polyhedral. The body 3 comprises a central bore 15 adapted to receive a sampling tube integral with a valve of a vial containing a fluid under pressure or to itself constitute with its walls this sampling tube. This bore 15 opens into a manifold 6 formed in the body, 10 above the bore 15. The body 3 comprises a parallelepipedal housing 7 open by one of its small faces on the collector 6. On both sides of the sagittal axis of the housing 7 are formed cells 13 whose function is explained later. The bottom of the housing 7 has an indentation forming a half-chamber 11a. This half chamber 11a is provided to cooperate, as described below, with a corresponding half-chamber carried by the cover 4 to form a chamber 11 for agitating the pressurized fluid delivered by the push button. The half chamber 1a has a form of revolution, for example biconical in the example shown, whose axis coincides with the sagittal axis of the push button 2. It is placed in the housing 7 so that one of its ends opens at the periphery of the body 3 by a narrow notch provided to form a spray orifice 21. The indentation also forms a supply channel 12, one end of which opens into the manifold 6 and the other into a side wall of the chamber 11a. The lid 4 comprises, in a position symmetrical to the housing 7 with respect to the axis of the hinge 5, a parallelepipedal block protruding, said counterform 8, whose dimensions are adapted to fit into the housing 7 when the The upper face of the counterfoil 8 also has a hollow recess forming a half-chamber 1b corresponding to the half-chamber 11a of the housing 7. The two half-chambers 11 have and 1 lb are adapted to form a stirring chamber 3033269 10 11 when the counterfoil 8 of the lid 4 is engaged in the housing 7 of the body 3 when the lid is folded down on the body. The indentation formed on the upper face of the counterfoil 8 may also comprise a second supply channel 12, one of its ends opening into a side wall of the half-chamber 1b. The lid 4 also comprises, on either side of the counterfoil 8, corresponding openings 14, when the lid is folded over the body, to the cells 13 formed on either side of the housing 7. In order to be able to fold the cover 4 on the body in a precise position and maintain it in this position, positioning and hooking means, in the form of centering pins 9 and centering holes 10 are provided respectively on the body and the lid. Of course, any variant in the position of these means (pins on the lid and holes in the body, pin / hole pairs alternately on the body or lid, etc.) would be equivalent.

Advantageously, the pins 9 may have a bulge or an undercut at their end to allow elastic locking of the pins in the holes. When the lid 4 is folded down and fastened to the body 3, the counterfoil 8 fits into the housing 7, the upper face of the counterfoil bearing against the bottom of the housing to form a contact plane in the vicinity of the chamber agitator 11 thus formed. Note that in the example shown in Figure 2, the channels 12 are placed on either side of the chamber 11 and open in the latter substantially opposite one another. However, one of the channels is above the plane of contact and the other is below. This advantageous arrangement makes it possible to generate a swirling motion of the fluid under pressure inside the stirring chamber 11 before the fluid is ejected through the spray orifice 21 formed by the two end notches of the half-chambers. 1 1 a and 1 1 b. According to the invention, in order to achieve a perfect seal of the push button 2, with the exception of the bore 15 and the spray orifice 21, the push button 2, once the cover 4 folded down and fixed on the body 3, is overmolded by a yoke 25, as shown in section in Figure 5. The push button 2, once covered by the yoke 25 forms a vaporizer head 1. For clarity of the drawing, there is shown the cut the lid and the body with different hatching, although the lid and the body were molded in one piece in the open position. The overmolding of the yoke 25 is made of a preferably thermoplastic synthetic material, which may be identical or different from the material used for molding the push button 2.

When overmolding the yoke 25 on the push button 2, in addition to a layer of material molded on the outside of the push button, on its face opposite the bore 15 and on its periphery, the synthetic material in the liquid state penetrates the openings 14 formed on either side of the counterfoil 8 and fills the cells 13 thus making it possible to seal around the contact plane 26 between the counterfoil 8 and the bottom of the housing 7. In addition, counterform 8 has on the periphery of its upper face very thin protruding ridges, said fins 16 reflow, which crash against the bottom of the housing 7 when the lid 4 is folded. Due to their small size, these fins 16 are rapidly heated by the contact of the overmoulding material entering the cells 13 and melt to make a weld bead of the counterform 8 on the bottom of the housing 7 while preventing the material from the screed penetrate between these. When over-molding the yoke 25, the overmoulding mold provides a pin adapted to be housed in the spray orifice 21 and prevent its closure by the overmoulding material. The shape of this pin makes it possible to make an opening 24 facing the spray orifice 21. We will now briefly describe a second embodiment of a vaporizer head 1 in connection with Figures 3, 4 and 6 of the accompanying drawing.

In this embodiment, there is a push button 2 comprising a body 3 connected to a cover 4 by a hinge 5 formed by a flexible tongue, the assembly being molded in one piece of synthetic material preferably thermoplastic. The body 3 comprises a central bore 15 opening into a manifold 6. A feed channel 12 'of rectangular cross-section flattened portion of the collector 6 towards the periphery of the body 3 along the sagittal axis and opens in the upper part of A recess 17 formed on the periphery of the body 3. The cover 4 is in the form of a rectangular flat plate with rounded edges corresponding to a correspondingly shaped housing of the body 3. The cover 4 terminates at its opposite end. at the hinge 5 by an end plate 18, orthogonal to the cover, whose periphery corresponds to the shape of the recess 17. The end plate 18 is pierced at its center by a spray orifice 21. The thickness of the end plate 18 is designed so that, when the lid 4 is folded over the body 3, the end plate 18 closes the recess 17 on its periphery while leaving a free space between the bottom wall 27 of the recess 17, orthogonal to the sagittal axis and the end plate 18. This free space is delimited by two shoulders 20 of the end plate 18 placed on either side of the orifice 21 and bearing on the bottom wall 27. The bottom wall 27 of the recess 17 comprises reliefs 19 of stirring in the shape of an arc of a circle whose thickness is substantially equal to that of the shoulders 20. This free space between the bottom wall 27 and the plate terminal 18 forms a stirring chamber 11 'in the center of which is placed the orifice 21 spraying.

The lid 4 also comprises two L-shaped resilient latches 22 adapted to cooperate with two recessed lugs 23 in the body 3 on either side of the supply channel 12 'in order to position and lock the lid 4 on the body 3 in the folded position. The cover 4 further comprises two slots 14 'placed at the bottom of the catches 22 and 3033269 13 of the reflow fins 16 around an area of the cover covering the collector 6 and the feed channel 12' as well as along the periphery of the cover. the terminal plate 18. The pressurized fluid distribution circuit thus passes through the bore 15 and the collector 6. The fluid then flows in the feed channel 12 'and suddenly changes direction to enter the chamber stirring 11 '. The fluid is then deflected by the stirring projections 19 in the form of an arc of a circle, thus making it possible to obtain a swirling motion before being ejected through the spray orifice 21. As seen previously in connection with the first embodiment of the invention, the vaporizer head 1 is completed by overmolding a yoke 25 around the push button 2 with a second synthetic material, preferably thermoplastic. Regardless of the embodiment of the vaporizer head 1, the overmolding of the yoke 25 provides a vaporizer head having a reinforced seal, an unmountable assembly and an appearance and / or a uniform feel. Depending on the material used for the overmolding of the screed, it is thus possible to obtain a soft and elastic touch of the spray head with a material having properties similar to the elastomers 20 or to obtain a very aesthetic visual appearance with a material such as PETG (polyethylene terephthalate glycol) or PMMA (polymethyl methacrylate) with or without dye and / or loaded with metallic or pearlescent particles, for example, without encountering the technical problems that would be encountered to achieve fully a push button with these materials.

The method of manufacturing a vaporizer head as described above is preferably carried out by means of a thermoplastic injection mold having two positions. Each position is coupled to an injection unit of a bi-material injection press fed with suitable material.

In a first position, the mold is adapted to inject a first material into a cavity whose shape makes it possible to produce the body 3 and the lid 4, connected by a flexible tongue forming a hinge, the body and the lid being molded flat. simultaneously and in the open position.

In a second position, the mold is adapted to inject a second material for molding the body and the lid in their lid down position on the body. The mold comprises two shells, a first fixed shell in which are formed the injection channels from the injection heads 10 and a second shell at least partially rotatable between the first and second position. In particular, the second shell comprises two projecting cores, diametrically opposite with respect to the axis of rotation of the movable part of the second shell, making it possible to form and / or maintain the lower part of the body 3, comprising an axial core forming the interior of the bore 15 and the collector 6 and the recess between the outer skirt of the body and the walls of the bore. The second shell also has at least one fixed portion adapted to form the cover plate 4. In an initial step, the mold is closed and the first material is injected into the first position, thus forming a body and in an open position . The mold is then opened and ejectors release the cover 4 that a cam system flaps and locks on the body 3 by elastically engaging the holes 10 and the pins 9 of centering or latches 22 in the chins 23. The rotating part of the second shell then makes a half turn towards the second position, carrying with it the body and the lid in the folded position. The closed pushbutton then arrives on the second position of the mold. The mold is closed above the push button, enclosing it in a cavity adapted to perform overmolding of the yoke 25 formed in the first shell of the mold. The second injection head 30 then injects the second synthetic material to form the overmolded coping.

Simultaneously, in the first position, the first injection head injects the first material to make a second body / cover assembly. The mold then opens, the overmolded vaporizer head is ejected from the second position, the second body / lid assembly is folded into the first position and the rotating part of the second shell is turned around and positioned in the first position. overmolding cavity. The process is repeated, providing a lid body assembly in position and an overmolded vaporizer head terminated upon each rotation of a half turn of the second shell. Of course, this description is given by way of illustrative example only and the person skilled in the art may make numerous modifications without departing from the scope of the invention, such as for example making vaporizer heads of different shapes from those described. above or use one or more thermoplastic materials or even thermosetting materials with a drying / polymerization time in each position of the mold, etc.

Claims (5)

CLAIMS1 / - Spray head (1), comprising a push button (2) comprising a pressurized fluid distribution circuit comprising a collector (6) adapted to cooperate with a dispensing valve of said fluid, at least one channel (12, 12 ') connecting the manifold to a stirring chamber (11, 11') and a spray orifice (21), characterized in that the push button comprises a body (3) on which is hinged a cover ( 4), the body and the lid being molded in one piece in a first synthetic material, said cover, in the closed position, forming with said body said stirring chamber (11, 11 '). 2 / - Vaporizer head according to claim 1, characterized in that the cover (4) and the body (3) each comprise a hollow recess forming, when the cover is folded down on the body, the chamber (11) of agitation and the spray orifice (21) and at least one supply channel (12) connecting the agitation chamber to the collector (6). 3 / - Vaporizer head according to claim 2, characterized in that each footprint forms a separate supply channel (12), the supply channels being symmetrical with respect to a contact plane (26) between the body (3). ) and the cover (4) in the vicinity of the chamber (11) stirring and placed on either side thereof. 4 / - Vaporizer head according to claim 1, characterized in that the body (3) comprises a channel (12 ') feeding into a recess (17) provided on the periphery of the body, said recess being closed by a terminal plate (18), integral with the cover (4), 25 carrying the orifice (21) of spraying, and providing a space forming the chamber (11 ') of agitation between said recess and said end plate. 5 / - Vaporizer head according to claim 4, characterized in that the recess (17) comprises reliefs (19), said reliefs of agitation, bearing on the plate (18) terminal. 6 / - Vaporizer head according to any one of claims 1 to 5, characterized in that the body (3) and the cover (4) comprise means (9, 10, 22, 23) for positioning and hooking cooperating with each other to keep the lid folded over the body. 5 7 / - Vaporizer head according to any one of claims 1 to 6, characterized in that the push button (2), lid folded over the body, is coated with a molded cap (25) having an opening (24). ) facing the orifice (21) for spraying the push button. 8 / - Vaporizer head according to claim 7, characterized in that at least one of the lid (4) and the body (3) comprises fins (16) reflow, adapted to weld the lid on the body when overmolding of the screed (25). 9 / - Method of manufacturing a spray head according to claim 7, made of synthetic material, characterized in that: - a first synthetic material is injected into a mold adapted to form a body (3) and a cover (4) a push button (2), the body and the cover being secured by a tongue of material adapted to form a hinge (5) between the body and the lid, - the lid is folded over the body, 20 - one overmold a clevis (25) on the push button with a second synthetic material so as to make the body integral with the lid. 10 / - The method of claim 9, characterized in that a mold is used with two positions, adapted to: - form the body (3) and the lid (4) in the open position in a first position, - close the lid on the body during a transition between the first position and a second position, - overmoulding the yoke (25) on the push button in said second position. A method according to any one of claims 9 or 10, characterized in that the overmolding of the yoke (25) is performed with a synthetic material distinct from the first material adapted to impart sensory characteristics and / or predetermined aesthetics at the spray head (1).