FR2678906A1 - Device for spraying a predetermined dose of a fluid product, and its filling method - Google Patents

Abstract

Device for spraying a single dose of a fluid product in separated form, comprising at least: - a cylindrical reservoir (1) containing the said dose of product, - a piston (2) sliding in the said cylindrical reservoir (1), - a means (3, 4) of actuating the piston (2), - an outlet passage (5, 6) able to connect with the said cylindrical reservoir (1), the said piston (2) being displaceable with respect to the said actuating means (3, 4) between a storage position in which it cuts off the connection between the said outlet passage (5, 6) and the said cylindrical reservoir (1), and an actuating position in which it connects the said outlet passage (5, 6) with the cylindrical reservoir (1), characterised in that the piston (2) is held in its storage position by jamming.

Description

 The present invention relates to a device for spraying a predetermined dose of a fluid product, and to its filling method. More particularly, the invention relates to a device containing a single dose of product and disposable after emission of this dose. The product to be sprayed can be a drug, a cosmetic or the like. The device according to the invention is more specifically intended for nasal sprays, but could be used for other purposes: ear sprays, sublingual sprays, etc.

Such devices are known in the state from hand. For example, the document
EP-AO 311 863 describes a device comprising a cylindrical reservoir of fluid product in which slides a piston secured to an actuating pusher. The device further includes an outlet passage which communicates with the product reservoir. However, this outlet passage is not airtight, so that the product contained in the tank can oxidize or become polluted on contact with air during its storage.

 The object of the present invention is in particular to avoid this drawback, without significantly increasing the cost of the device, which is disposable after a single actuation.

The present invention therefore relates to a device for projecting in divided form a single dose of a fluid product, comprising at least:
- a cylindrical reservoir containing said dose of product,
- a piston sliding in said cylindrical tank,
a means for actuating the piston,
an outlet passage which can communicate with said cylindrical tank, said piston being movable relative to said actuation means between a storage position where it cuts the communication between said outlet passage and said cylindrical tank, and an actuation position where it puts said outlet passage into communication with the cylindrical tank,
characterized in that the piston is held in its storage position by jamming, and can only release the outlet passage if there is sufficient pressure in the cylindrical tank to loosen it.

 In a particular embodiment of the invention, the actuating means comprises a cylindrical part which extends between an end close to the cylindrical tank and a stop more distant from the cylindrical tank, said end close to the product tank is integral with a crown, said product outlet passage is arranged at least partially inside said cylindrical part of the actuating means, said product outlet passage opens out of said cylindrical part between said crown and said stopper, in the vicinity of said crown, the piston has an internal sleeve which slides on said cylindrical part of the actuating means, and said piston is in sealed contact with said crown when it is in its storage position.

 Advantageously, the piston has an outer peripheral sealing lip which slides in leaktight manner in the cylindrical tank and which is wedged between the tank and the crown when the piston is in its storage position. In a particular embodiment, the crown comprises an annular rib directed towards the piston, the piston comprises an annular groove adapted to receive the rib of the crown, the piston composes an annular rib directed towards the crown and inside said annular groove, and the crown has an annular groove adapted to receive the annular rib of the piston. In this case, the crown may include at least one passage which communicates the reservoir with the groove of the piston when said piston is in its storage position, and the rib of the piston is then in sealed contact with the groove of the crown.

 Advantageously, the cylindrical reservoir has a bottom and the crown has a face directed towards said bottom and having a shape substantially complementary to said bottom, and said face of the crown abuts against said bottom at the end of the piston stroke, so that substantially all of the product contained in the tank is expelled.

 The piston can optionally be urged towards its storage position by elastic means.

 The internal sleeve of the piston can be in abutment against the stop of the actuating means when the piston is in its storage position, and the displacement of the piston towards its actuating position is then effected by deformation of at least part of said internal sleeve. Advantageously, the internal sleeve of the piston then has longitudinal slots over a part of its length in the vicinity of said stop of the actuating means, so as to facilitate the deformation of said internal sleeve.

The piston sleeve can be applied in sealed contact against said stop of the actuating means when the piston is in its actuating position. Advantageously, said abutment has a concave annular surface surrounding the cylindrical and concavity wall directed towards the sleeve, and said concave annular surface deforms radially inward a free end of said sleeve when the piston is in its actuation position. Alternatively, the piston sleeve can slide with sealing on the cylindrical wall of the actuating means
In a particular embodiment, the piston comprises a cylindrical part which slides on a cylindrical part complementary to the crown while maintaining cut off the communication between the cylindrical reservoir and the product outlet passage as long as the piston has not moved away from the crown of a predetermined distance.

 In another particular embodiment of the invention, the cylindrical product reservoir has a filling orifice capable of receiving a stopper ball, and said orifice is extended towards the outside of the reservoir by a duct provided with longitudinal slots, said ball can be forced into said conduit in an intermediate position where it allows the communication of the tank with the outside via said longitudinal slots.

The present invention also relates to a method of filling the above-mentioned device, comprising at least the following steps:
- introduction of the device into a vacuum chamber, maintained under vacuum,
- introduction into the cylindrical tank of a predetermined volume of
product,
- vacuum closure of the cylindrical tank,
characterized in that said predetermined volume of product is measured by a measurement means external to the device of the invention and said volume can have any value less than or equal to the total volume of said cylindrical tank.

The present invention also relates to a method of filling the above-mentioned device, comprising at least the following steps:
- introduction of the device into a vacuum chamber,
- introduction into the cylindrical tank of a predetermined volume of
product,
- evacuation of the vacuum chamber,
- vacuum closure of the cylindrical tank,
characterized in that said predetermined volume of product is measured by a measurement means external to the device of the invention and said volume can have any value less than or equal to the total volume of said cylindrical tank.

 Other characteristics and advantages of the invention will appear during the following detailed description of several embodiments of the invention, given by way of non-limiting examples, with reference to the accompanying drawings.

In the drawings:
FIG. 1 is a view in longitudinal section of an embodiment of the device according to the invention, in the storage position,
FIG. 2 is a perspective view of the device in FIG. 1,
FIG. 3 is a detailed view of part of the device in FIG. 1,
FIG. 3A is a bottom view of the crown 10 of FIG. 3, in the direction A of FIG. 3,
FIG. 3B is a view similar to FIG. 3, showing a variant of the device of the invention,
FIG. 4 is a partial view in longitudinal section of the device in FIG. 1, in the end of actuation position,
FIG. 5 is a partial view in longitudinal section of a variant of the device according to the invention, in the storage position,
FIG. 6 is a partial view in longitudinal section of another variant of the device according to the invention, in the storage position,
FIG. 7 is a partial view in longitudinal section of the device in FIG. 6, in the end of actuation position,
FIG. 8 is a sectional view similar to that of FIG. 3, for a variant of the invention particularly suited to the configurations of FIGS. 6 and 7,
FIG. 9 is a partial view in longitudinal section of another variant of the device according to the invention, in the end of actuation position,
FIG. 10 is a detailed view of the device in FIG. 9, and
- Figure 1 1 is a sectional view of another variant of the device according to the invention.

 Figures 1 to 4 show a first embodiment of the device according to the invention. This device is intended to project a single dose of fluid, generally of the order of a few milliliters. The device of the invention is therefore small, and measures a few centimeters in its largest dimension. it is generally made of plastic.

 As shown in Figure 2, the device according to the invention comprises a pusher 3 provided with an outlet nozzle 18 having an enlarged base 19 from which extends radially outward a support surface 20 extended by a skirt 21. Inside the skirt 21 is mounted a pump body 22 comprising support wings 23 adapted to slide in said skirt 21. The device can be actuated by being held between the thumb and one or two fingers , the thumb being applied against the support wings 23 and the other fingers being applied against the support surface 20. To facilitate actuation, the skirt 21 generally has a recess 24 allowing the passage of the thumb.

 With reference to FIG. 1, the pump body 22 comprises a cylindrical reservoir 1 which extends between an open end 25 and a bottom 16 provided with a filling orifice 26. The filling orifice 26 can be closed by a ball 27 force-fitted into said orifice, or by any other closure means.

Advantageously, the skirt 21 of the pusher 3 has at its free end an internal snap-on lip 28 which makes it possible to maintain said support wings 23 inside said skirt 21.

 The enlarged base 19 of the outlet nozzle 18 is constituted by a cylindrical wall 29 arranged around the cylindrical tank I, and which extends between the bearing surface 20 and an annular wall 9 which itself extends radially inwards to the outlet end piece 18. The outlet end piece 18 extends between said annular wall 9 and an outlet end 30 comprising an outlet opening 6.

The outlet end piece 18 is hollow, and extends a certain distance inside the cylindrical wall 29 of the enlarged base 19, by a cylindrical wall 7 which extends to one end 8. Thus, the the outlet end piece 18 and the cylindrical wall 7 delimit a longitudinal cylindrical channel 31 which communicates with the outlet orifice 6.

 A rod 4 also cylindrical is force fitted into the longitudinal channel 31. The rod 4 extends from a first end 32 placed in contact with the outlet end 30 of the outlet nozzle 18, up to beyond end 8 of the cylindrical wall 7, where said rod 4 is extended radially outward by a ring 10. The rod 4 has over its entire height one or more external grooves 5 which communicate with the outlet orifice 6, generally by grooves formed on the first end 32 of the rod 4, in a well known manner.

 The device of the invention further comprises a piston 2 which slides in the cylindrical tank 1, and which can slide on the cylindrical wall 7 of the pusher between the ring 10 and the annular wall 9 forming a stop. In the example shown in Figure 1, the piston 2 has an internal sleeve 11 which extends to a free end 43 close to the annular wall 9 of the pusher, and which slides on the cylindrical wall 7 of the pusher. In addition, the piston 23 has an external skirt 33 which slides in leaktight manner in the cylindrical tank 1.

 FIG. 3 shows in detail the structure of the piston 2 and of the crown 10.

The crown 10 has an annular rib 12 directed towards the piston, and the piston 2 has an annular groove 13 disposed opposite the annular rib 12.

The annular groove 13 of the piston is delimited externally by an outer peripheral sealing lip 34 of the skirt 33, which slides in sealed contact in the cylindrical tank 1, and by a rib 14. The crown 10 further comprises a groove 15 adapted receiving said rib 14. When the piston 2 is in a storage position, as shown in FIG. 3, the annular rib 12 of the crown 10 is force fitted into the annular groove 13 of the piston, and wedged between the lip d seal 4 and the rib 14 of the piston. When mounting the device, the piston 2 is first assembled on the crown 10 by fitting the annular rib 12 into the groove 13. Then the rod 4 is force-fitted into the longitudinal channel 31 of the pusher and the piston 2 is introduced into the cylindrical reservoir 1. To facilitate this introduction, the cylindrical reservoir 1 advantageously comprises an internal chamfer 41 at its open end. When the sealing lip 34 is introduced into the chamfer 41, it is progressively deformed radially inwards, so that it comes to tighten the rib 12 which is thus compressed between the rib 14 and the lip 34.

 In the particular example shown in FIGS. 3 and 3A, the contact between the lip 34 and the rib 12 is not sealed, since the ring 40 has one or more slots 40 at its outer periphery, which make the reservoir of product 1 with groove 13 of the piston. In this example, the seal between the piston 2 and the crown 10 is ensured by the contact between the rib 14 and the groove 15. This seal is reinforced by the radial tightening due to the sealing lip 34, which applies the rib 12 between the rib 14. Thus, the rib 14 is also wedged in the groove 15, and participates in the wedging of the piston 2 on the crown 10.

 Although they are advantageous for reasons which will be seen below, the slots 41 can be omitted.

 Optionally, as shown in FIG. 3B, the wedging and sealing between the piston 2 and the crown 10 could be ensured by the contact between the sealing lip 34 and the crown 10, provided that said crown 10 no longer comprises slots 40. I1 is then no longer necessary to provide a rib or groove on the piston 2 or the crown 10.

 When a user holds the device between the thumb and two fingers, and simultaneously presses on the support wings 23 of the pump body 22 and on the support surface 20 of the plunger 3, the piston 2 tends to descend with the pusher 3 towards the bottom 16 of the cylindrical reservoir 1. The product contained in the cylindrical reservoir 1 is generally incompressible, so that the pressure of said product increases without appreciable displacement of the pusher 3 relative to the pump body 22. This pressure exerts on the piston 2 a force which tends to move it away from the bottom 16 of the cylindrical reservoir 1. When the crown 10 has the slots 41 of FIG. 3, the pressure of the product stexes on a larger surface of the piston, and therefore the force applied to the piston by said pressure is all the greater, which facilitates the loosening of the piston 2. When this force is sufficient to separate the piston 2 from the crown 10, the piston 2 is pushed back towards the ha ut while the pusher 3, with the rod 4 and the crown 10, begins to descend towards the bottom 16 of the cylindrical reservoir 1. In this way, the internal sleeve 11 of the piston 2 is pushed into abutment against the annular wall 9 of the pusher 3, and a space 35 is created between the piston 2 and the crown 10, as shown in FIG. 4. When the sleeve 1 1 is applied in abutment against the annular wall 9 under the effect of the pressure prevailing in the reservoir product 1 and friction between the piston 2 and said reservoir 1, the contact between the sleeve 1 1 and the annular wall 9 is sealed. Advantageously, the annular wall 9 has an annular surface 42, clearly visible in FIG. 4A, surrounding the cylindrical wall 7 and forming an acute angle with said cylindrical wall 7. The free end 43 of the sleeve 11 abuts against this surface 42, of so that by wedge effect, the surface 42 deforms the free end 43 of the sleeve 11 radially inwardly, and applies it against the cylindrical wall 7 of the pusher. In addition, this deformation is accompanied by a significant pressure applied by the surface 42 on the sleeve 11. Thus, the free end 43 of the sleeve 1 1 is in sealed contact with on the one hand the annular surface 42, and d on the other hand with the cylindrical wall 7.

The space 35 places the cylindrical reservoir 1 in communication with the grooves 5 of the rod 4, so that the product contained in said cylindrical reservoir 1 can be expelled through the passage 35, the grooves 5 and the outlet orifice 6, while the piston 2 and the crown 10 descend into said cylindrical tank 1, towards the bottom 16. This movement stops when the crown 10 abuts against said bottom 16. Advantageously, the crown 10 has a face 17 directed towards the bottom 16 which has a shape substantially complementary to that of said bottom 16 and of the ball 27, so that when the crown 10 is in abutment against the bottom 16, substantially all of the product contained in the cylindrical tank 1 has been expelled. This limits the loss of part of the product contained in the cylindrical tank, which is particularly useful when the product is expensive, or when its use is regulated (case of drugs based on prohibited drugs)
FIG. 5 represents a variant of the device of FIG. 1, in which an elastic means such as a helical spring 36 is disposed between the annular wall of the pusher 3 and the piston 2, so as to elastically bias the piston 2 towards the crown 10. This variant can be useful especially in the case where the volume of the dose to be projected is relatively large, and where the stroke of the piston 2 in the cylindrical reservoir I is relatively large. Indeed, it could be possible while a user interrupts or slows down the movement of the piston 2 in the cylindrical tank 1 during the stroke of said piston 2. In this case, the pressure inside the cylindrical tank 1 decreases, so that the helical spring 36 pushes the piston 2 towards the crown 10, again isolating the cylindrical tank 1 from the outlet grooves 5. The piston 2 then separates from the crown 10 only when the pressure in the cylindrical tank 1 has again become sufficient to overcome the force of the spring 36. This guarantees a fine spraying of the product at the outlet of the device. In addition, the helical spring 36 reinforces the jamming of the piston 2 on the crown 10 when said piston is in its storage position.

 Figures 6 and 7 show another variant of the device of the invention, in which the internal sleeve 1 1 of the piston 2 is placed in abutment against the annular wall 9, when the piston is in its storage position. Thus, the displacement of the piston towards its actuation position, as shown in FIG. 7, takes place by deformation of a part of the internal sleeve 11 of the piston, radially outward, in the vicinity of the annular wall 9 of the pusher.

 In this variant of FIGS. 6 and 7, it is particularly advantageous for the crown 10 to have a cylindrical surface 44 on which a complementary cylindrical part of the piston slides with sealing. If the height of the cylindrical surface 44 is called h, the piston 2 must move away from the crown 10 by the distance h before freeing the passage between the product reservoir 1 and the outlet grooves 5. This distance h traveled by the piston corresponds to a predetermined compression of the sleeve 11 which itself corresponds to a predetermined force exerted by the sleeve 1 1 on the piston 2: thus, it is ensured that the product is expelled only if the pressure inside the tank 1 reaches a predetermined value, and therefore said product is sprayed finely.

 FIG. 9 represents a variant of the device of FIGS. 6 and 7, in which the internal sleeve 11 of the piston has longitudinal slots 37 which extend over part of its length in the vicinity of the annular wall 9 of the pusher 3, so to facilitate the deformation of said internal sleeve 11.

 In the variant of FIG. 9, the seal between the piston 2 and the pusher can no longer be ensured at the level of the annular wall 9. It is then possible to produce a peripheral sealing lip 45 between the sleeve 11 of the piston and the cylindrical wall 7 of the pusher, as shown in FIG. 10. This lip 45 could be formed for example inside the sleeve 11, but could also be formed outside the cylindrical wall 7. It will be noted that the variants described above of the device of the invention could also be equipped with the sealing lip 45, replacing the sealing by abutment of the sleeve 11 against the wall 9.

The device of the invention can be filled with product according to the following method:
- introduction of the device into a vacuum chamber, the orifice 26 of the tank
1 being directed upwards,
- evacuation of the vacuum chamber,
- introduction into the cylindrical tank 1 of a measured product volume
by external measuring means, said volume being less than the volume
total of said cylindrical tank 1, and
- vacuum closure of orifice 26.

 The step of placing the vacuum chamber under vacuum can be placed after the step of introducing into the tank 1 a volume of product measured externally.

 Thus, the volume of product introduced into the tank 1 is chosen between 0 and a maximum volume. This is particularly advantageous insofar as the same spraying device according to the invention can be used to contain doses of various products, which makes it possible to produce in larger series and therefore at lower cost. After plugging the orifice 26 and leaving the vacuum chamber, if the volume of product is less than the total volume of the reservoir 1, the piston 2 slides in the reservoir 1 under the effect of the atmospheric outside pressure, substantially until the interior volume of the tank 1 becomes substantially equal to the volume of product it contains.

 As shown in FIG. 11, the enlarged base 19 of the endpiece 18 can include slots 46, which make it possible to precisely adjust the position of the reservoir 1 relative to the piston 2, in order to precisely fix the maximum volume of product which can be contained in said tank 1.

 In addition, the slots 46 make it possible to press on the piston 2 and not on the pusher 3 during the positioning of said piston in the cylindrical tank 1. This prevents the piston 2 from leaving its storage position when it is put in place, due to the friction between said piston and the cylindrical reservoir 1.

 Advantageously, the orifice 26 of the bottom 16 can be extended towards the outside by a conduit 47 provided with longitudinal slots 48. Thus, the ball 27 can be partially introduced into the conduit 48 without blocking the orifice 26, which then communicates with the exterior through the slots 48. The manufacturer who fills the reservoir 1, which is generally different from that which produced the device, then only has to push the ball 27 up to the orifice 26 to stop said orifice after filling of reservoir 1.

Claims (16)

 1.- Device for projecting in divided form a single dose of a fluid product, comprising at least:  - a cylindrical tank (1) containing said dose of product,  - a piston (2) sliding in said cylindrical tank (1),  - an actuating means (3, 4) of the piston (2),  - an outlet passage (5, 6) which can communicate with said cylindrical tank (1), said piston (2) being movable relative to said actuating means (3, 4) between a storage position (fig. 1) where it cuts the communication between said outlet passage (5, 6) and said cylindrical tank (1), and an actuation position (FIG. 4) where it places said outlet passage (5, 6) in communication with the cylindrical tank (1),  characterized in that the piston (2) is held in its storage position by jamming, and can only release the outlet passage (5, 6) if there is sufficient pressure in the cylindrical tank (1) to loosen it .  2.- Device according to claim 1, further characterized in that the actuating means (3, 4) comprises a cylindrical part (7) which extends between an end (8) close to the cylindrical reservoir (1) and a stop (9) further from the cylindrical tank (1), said end (8) close to the product tank is integral with a crown (I 0), said product outlet passage (5, 6) is arranged at least partially inside said cylindrical part (7) of the actuating means, said product outlet passage opens out of said cylindrical part (7) between said crown (10) and said stop (9), in the vicinity of said crown (10), the piston (2) has an internal sleeve (11) which slides on said cylindrical part (7) of the actuating means, and said piston (2) is in sealed contact with said crown (10) when it is in its storage position.  3.- Device according to claim 2, further characterized in that the piston (2) comprises a sealing lip (34) external device which slides in leaktight manner in the cylindrical tank (1) and which is wedged between said tank (1) and the crown (10) when the piston (2) is in its storage position.  4.- Device according to claim 3, further characterized in that the crown (10) comprises an annular rib (12) directed towards the piston (2), the piston comprises an annular groove (13) adapted to receive the rib ( 12) of the crown, the piston (2) comprises an annular rib (14) directed towards the crown (10) and inside said annular groove (13), and the crown (10) comprises an annular groove (15) adapted to receive the annular rib (14) of the piston (2).  5.- Device according to claim 4, further characterized in that the crown (10) has at least one passage (40) which communicates the reservoir (1) with the groove (13) of the piston (2) when said piston (2) is in its storage position, and in that the rib (14) of the piston is in sealed contact with the groove (15) of the crown (10).  6 Device according to any one of claims 2 to 5, further characterized in that the cylindrical tank (1) has a bottom (16), and the crown (10) has a face (17) directed towards said bottom (16) and having a shape substantially complementary to said bottom (16), and in that said face (17) of the crown (10) abuts against said bottom (16) at the end of stroke of the piston (2), so that substantially all of the product contained in the tank (1) is expelled (Figure 4).  7.- Device according to any one of claims 2 to 6, further characterized in that the piston (2) is biased towards its storage position by an elastic means (36, 11).  8.- Device according to any one of claims 2 to 7, further characterized in that the internal sleeve (11) of the piston (2) bears against the stop (9) of the actuating means (3, 4 ) when the piston (2) is in its storage position, and the displacement of the piston (2) towards its actuation position is effected by deformation of at least part of the internal sleeve (11) (Figures 7 and 8) .  9.- Device according to any one of claims 2 to 8, further characterized in that the sleeve (11) is applied in sealed contact against said stop (9) when the piston is in its actuation position.  10.- Device according to claim 9, further characterized in that said stop (9) comprises an annular surface (42) concave, surrounding the cylindrical wall (7) and of concavity directed towards the sleeve (11), and in that that said concave annular surface (42) deforms radially inward a free end (43) of said sleeve (11) when the piston (2) is in its actuation position.  11.- Device according to claim 8, further characterized in that the internal sleeve (11) of the piston (2) has longitudinal slots (37) over part of its length in the vicinity of said stop (9) of the means d 'actuation (3, 4), so as to facilitate the deformation of said internal sleeve (11) (Figure 8).  12.- Device according to any one of claims 2 to 11, further characterized in that the sleeve (11) of the piston (2) slides with sealing on the cylindrical wall (7) of the actuating means.  13.- Device according to any one of claims 2 to 12, further characterized in that the piston (2) comprises a cylindrical part (14) which slides on a complementary cylindrical part (15) of the crown (10) in now cut off the communication between the cylindrical reservoir (1) and the podruit outlet passage (5, 6) as long as the piston (2) has not moved away from the crown (10) by a predetermined distance (h) .  14.- Device according to one of the preceding claims, further characterized in that the cylindrical reservoir (1) of product comprises a filling orifice (26) capable of receiving a ball (27) for plugging, and said orifice (26) is extended towards the outside of the reservoir (1) by a conduit (47) provided with longitudinal slots (48), said ball (27) being able to be force-fitted into said conduit (47) in an intermediate position where it allows the communication of the reservoir (1) with the outside via said longitudinal slots (48).  15.- A method of filling a device according to any one of claims 1 to 14, comprising at least the following steps:  - introduction of the device into a vacuum chamber, maintained under vacuum,  - introduction into the cylindrical tank (1) of a predetermined volume of  product,  - vacuum closure of the cylindrical tank (1),  characterized in that said predetermined volume of product is measured by a measurement means external to the device of the invention and can have any value less than or equal to the total volume of said cylindrical tank (1).  16.- A method of filling a device according to any one of claims I to 14, comprising at least the following steps:  - introduction of the device into a vacuum chamber,  - introduction into the cylindrical tank (1) of a predetermined volume of  product,  - evacuation of the vacuum chamber,  - vacuum closure of the cylindrical tank (1),  characterized in that said predetermined volume of product is measured by a measurement means external to the device of the invention and can have any value less than or equal to the total volume of said cylindrical tank (1).