FR2779416A1 - Cover cap for reusable closure - Google Patents

Abstract

The molded plastics cover cap (1) has a throat (3) with an opening closed by a stopper (20) and mounted in one piece with a closure having a skirt (40). The throat has at least three oblique grooves (71) and the skirt has lugs (44), the number of which is a multiple of the number of grooves.

Description

- 1 -

  CONTAINER HEAD MOUNTED IN ONE PIECE WITH A CLOSURE

REUSABLE

  s TECHNICAL FIELD The invention relates to a plastic head, which can be attached to any

  multidose dispenser packaging container, comprising a neck, the orifice of which is closed by a cover and mounted in one piece with a reusable closure as a stopper after rupture of the cover.

  This type of head is used in particular in flexible tubes intended for

  packaging of consumer hygiene products or even small containers or tubes, such as sample tubes, intended to contain cosmetic, hygiene or parapharmacy products.

STATE OF THE ART

  Patent application WO 97/39953 discloses a manufacturing process which makes it possible to produce a head comprising a neck connected by a tear-off annular portion to a cover sealing the orifice before rupture and provided with at least one skirt which, either alone, either attached to the body of a capsule, is permanently secured by snap-fastening on the head, near the seal. We will call this skirt hereafter, capsule skirt. The method described in WO 97/39953 comprises a step of manufacturing the capsule skirt by any known plastic molding technique, the capsule skirt being able to be alone or integral a full capsule. This capsule skirt can be molded separately. It can also, in an advantageous form of the method described in WO -2- 97/39953, be molded simultaneously with the head, but in a temporary position, forming with the top of said head a sort of overturned cap. s The cover is extended by a plate, the periphery of which is delimited by a contour which has a common axis of symmetry with the annular portion.

  tearable. Said periphery of the plate extending the cover is provided with at least three lugs.

  o The capsule skirt is open at one end and its internal wall is, at least partially, cylindrical, its section conforming to the shape of the periphery, excluding pins, of the plate in extension of the cover, the cylindrical part of the internal wall being provided with at least three cavities intended to accommodate the pins. After shaping the head and the capsule skirt, the capsule skirt is brought into view of the plate and then threaded by its first end around it until it comes to a standstill, this being caused by the introduction of the plate lugs in the cavities of the inner wall of the

capsule skirt.

  Grooves are optionally made on the internal wall of the capsule skirt in order to guide the pins in the direction of the cavities of the skirt during the threading of the latter around the plate. These grooves prove to be useful when the skirt has been produced separately because the lugs do not in this case benefit from the favorable initial positioning obtained immediately when

  the skirt was made simultaneously with the head.

  -3- When using the product in the tube for the first time, the user must

  first remove the seal that protects the product but prevents its distribution. To do this, he must tear the annular portion by imposing, by applying his fingers on the capsule skirt, either a movement of the rotation relative to the axis of the tube or a rocking movement.

  The assembly constituted by the cover, the plate provided with its lugs and the capsule skirt provided with the cavities occupied by the lugs of the plate is thus

  detached from the rest of the head and can be reused as a cap.

  the shape of the cover is particular: in addition to the tray, the cover also includes a transient portion between the tray and the tearable annular portion. This transient portion is either a stud or a crown which, after rupture of the tearable annular portion, serves as a sealing means

  attached to the bottom of the stopper thus formed.

PROBLEMS POSED

  The product obtained according to the process described in WO 97/39953 arouses an interest in the public, so much so that its success pushes to seek now an industrial solution allowing to perfect the

comfort of its use.

  Despite the opening advice specially written on the wall of the tube ("Turn to open; press to close"), it is difficult for the user to tear the lid properly, because he has to proceed in an unusual way and a little disconcerting. The ill-informed user in fact takes the lead by the capsule skirt and, feeling resistance to unscrewing, he tightens harder and harder on the skirt, trying to pull the cap outwards, while continuing to impose a certain rotational movement. As a result, the ill-informed user forces and twists the assembly, which has the double effect of deteriorating the appearance of the capsule skirt and leading to an ill-calibrated orifice, of too large a diameter.

  low. The distribution of the product is unsatisfactory. In addition, the user finds it difficult to fully push the capsule in.

  s Two types of attachment for the capsule have been proposed in document WO 97/39953. They required the use of a fairly large effort to ensure the forced insertion of the sealing means and the implementation of snap-fastening means: in the first case illustrated in FIG. 1, it is a question of '' a bead located on the end of the sealing stud and, in the second casing illustrated in Figure 7 of the same document, it is a bead located on the outer wall of the neck from snapping into a groove located on the wall

internal of the capsule skirt.

  The first type of fixing is rather suitable for small orifice diameters and does not allow tight plugs to be obtained after repeated use. With regard to the second type of attachment, the snap rim in fact acts as an obstacle which counteracts the sinking of the capsule so that the user, because of the effort to be provided, believes the capsule to be depressed fully and stops its effort, while the capsule is still secured to the head only by means of the sealing means, forced into the orifice of the neck. The capsule is therefore in fact badly fixed on the head and there is a risk of product leakage, in particular during untimely pressure exerted on the

  skirt of the tube, for example during baggage handling.

OBJECT OF THE INVENTION

  The object of the invention results from an improvement of the manufacturing process

  the main steps of which were described in WO 97/39953. The description,

  and the figures of WO 97/39953 form an integral part of the present document, which presents a modification of the design of the capsule skirt and of the neck,

  intended to improve the uncapping and closing conditions of the capsule.

  s The capsule skirt has in fact on its inner wall, in addition to the cavities and any guide grooves mentioned above, lugs of low height, located in the lower part, preferably regularly distributed and alternating with the angular position. cavities. To clarify the presentation, we will call these new lugs "skirt lugs", in contrast to the lugs described in WO 97/39953, located at the periphery of the plate in extension of the cover, and which will be called later

"lugs".

  On the other hand, the neck is provided on its outer wall with at least three oblique grooves which conform to the shape of a steep helix. These grooves are regularly distributed and the number of skirt lugs is an integer multiple of the number of oblique grooves. This allows for quick engagement

  skirt lugs in the grooves when screwing.

  The skirt lugs and the grooves of the neck are positioned so that after the capsule skirt has been inserted around the plate and the lugs have been trapped in the cavities of the capsule skirt, each lug of the skirt capsule is engaged in positive engagement in one of the oblique grooves made on the neck: the user must impose a rotational movement, in the direction of screwing or, preferably,

  unscrewing, to remove the seal on first use.

  This engagement in positive engagement of the skirt lugs in the grooves makes it possible to precisely guide a pure helical movement making it possible to achieve a clear rupture of the cover during the first use. The "skirt lugs + grooves on neck" system is then used to quickly screw the

cap the following times.

  s The geometrical conditions to be fulfilled to ensure the engagement in positive engagement of the skirt lugs in the grooves are to be defined according to the number of skirt lugs and the choice of their location. You must at least respect: * an overall dimension of the skirt lugs sufficient to accommodate them in the groove. The latter has a section enabling it to follow the shape of the outer envelope of the pins (for example rectangular if the pins are prismatic or cylindrical); * a longitudinal positioning of the skirt lugs such that the difference D1 between the level of the top wall thereof and that of the bottom wall of the cavities is greater than the difference D2 between the level of the entry of the

  grooves and that of the lower wall of the lugs.

  Uncapping is carried out intuitively by unscrewing, it is preferably sought to place the skirt pins as low as possible (D1-D2 as large as possible) so that they are guided in the oblique groove on

  sufficient length when uncapping.

  In a preferred form, these skirt lugs are distributed regularly over the internal wall of the capsule skirt. With regard to their circumferential positions, it suffices to ensure that the angular offset between the centers of the skirt lugs and of the cavities is equal to the angular offset between the centers of the lugs and the groove inlets. Preferably, a cavity will be placed in a median angular position of those of two neighboring skirt lugs, which leads to a geometric configuration favorable to a minimum distortion of the skirt during its

  threading around the plate in extension of the cover.

  The lower part of the inter-groove reliefs is provided with a circumferential notch extending one of the oblique grooves which surround said relief, the oblique groove-notch assembly forming a sort of inverted italic uppercase gamma, which may be called "bayonet ". This circumferential notch is limited in particular by two walls, one perpendicular to the axis of rotation, so that the lug can only follow an axial displacement of small amplitude and the other parallel to the axis of rotation which acts as a stop for the movement of the lug at the end of

  screwing. Arrived in this position, the lug can no longer move in rotation except for unscrewing.

  is These circumferential notches are especially useful after the rupture of the seal, when the cap is screwed on the neck in order to temporarily block the orifice. Initially, the lugs of the capsule skirt follow the helical path of the grooves. Then, they will be housed in the "bayonet" notches which allow a secure closure of the capsule in

stop position.

  To further improve the comfort of use at the time of the uncapping, it is advantageous to also make a spot welding between the capsule skirt and the plate in extension of the cover, just after the trapping of said cover lugs in said cavities, at the end of threading of the capsule skirt. This spot welding can be done by any known means (thermal welding, etc.). 8 - To facilitate ease of use when screwing on the capsule, it is

  It is also advantageous to draw a point at the top of the inter-groove reliefs, as this facilitates the guiding of the pins towards the entry of the grooves.

  s It is possible to produce the head by molding the capsule skirt simultaneously with the rest of the head, the capsule skirt being in a provisional position favorable to molding which gives the skirt + head assembly the shape of an inverted cap, as illustrated in Figures 3 and 4 of WO97 / 39953. The skirt is molded, connected by bridges to the rest of the head. At the end of the production line, a device presses on the skirt until these

  bridges then depression of the skirt around the plate extending the cover.

  In the example described below, we take advantage of the proximity of these bridges and

skirt lugs.

  s Whether the skirt was made separately or not, we then proceed to

  threading the skirt around the plate in extension of the cover.

  In the context of mass production, various arrangements can be made, intended to facilitate threading of the skirt around the plate. However, for economic reasons, these arrangements must be able to result in simple modifications to existing capping machines. In particular, it is important that the effort required to

  the penetration of the skirt is limited.

  Likewise, it is important to limit the effort necessary for uncapping, as well as the effort necessary for opening and closing the capsule obtained after tearing of the seal. For this purpose, a certain number of arrangements can be made in the design of the grooves, intended to reduce the friction forces between the internal wall of the capsule skirt and the external wall.

bottleneck.

  A first arrangement favorable to the limitation of efforts is the low height of the reliefs involved: in the case of sample tube (skirt diameter 16mm), the skirt pins are at most two tenths of a millimeter in height. A second favorable arrangement consists in reducing the height of the inter-groove reliefs, so as to prevent the internal wall of the capsule skirt from rubbing against these reliefs. The oblique grooves must have a sufficient depth to engage the skirt lugs to follow the helical movement imposed firstly to cut the cover properly, secondly to screw the capsule. We can for example give this part supporting the oblique grooves a frustoconical shape and keep a cylindrical shape (or frustoconical with

  a half angle at the top of very low value) to the other part, which supports the circumferential notches.

  A third favorable arrangement consists in reducing the number of inter-groove reliefs by replacing some of them, for example, by simple stops. It is preferable to provide six skirt lugs and it suffices to

  leave only an equal or divisive number (three for example) of reliefs

  grooves. The replacement of the inter-groove reliefs by simple stop stops widens the bottom of the grooves so that it is no longer necessary to screw the capsule to close: it can also be pushed in

  axial then a rotation until the pins meet the stops.

  - 10- These design modifications in the groove area are complementary and can be performed simultaneously on the same part. The retention of the capsule in the notches may however be insufficient, in particular when the number of interlocking reliefs is reduced to the strict minimum. In these cases, the stops that replaced the inter-groove reliefs can have a capital gamma form instead of a simple capital I form, the horizontal branch of the capital gamma being as small as possible. The Applicant preferred another solution which makes it possible to combine two closing actions: screwing and light snap-fastening. 10 This solution consists in providing the outside wall of the neck with a rod

  annular, of low radial height (less than that of the inter-groove reliefs) and disposed at the level of the upper wall of the circumferential notches, perpendicular to the axis of rotation and serving as a stop for the movement of the axial overhaul.

  The rod is "level" with these walls so that, when the capsule skirt is pressed around the cover, the pins come into positive engagement in the oblique grooves but do not come into contact with said rod. The friction and deformation that would result from such contact

  would unnecessarily increase the effort required for uncapping.

  Such a rod preferably has an asymmetrical section: a gentle slope facing upwards (outside of the tube) to facilitate the passage of the skirt lugs over the rod when the cap is screwed in or pushed in. A markedly more brutal slope on the other side which gives a sound effect (brutal elastic return of the capsule skirt towards its free, undeformed shape) and counteracts the axial withdrawal movement of the capsule by playing a role of stop to the movement lugs. The closing security is thus

- 1i1 -

  greatly improved, especially during untimely pressures

  on the skirt of the tube, for example during handling of luggage.

  A final object of the invention is a tube head provided with a capsule, said head and said capsule being provided with "bayonet" closing means described in the present application. These means correspond to lugs located on the internal wall of the capsule skirt and to oblique grooves extended by circumferential notches situated on the external wall of the neck. It goes without saying that a different arrangement of these means, o pins on the neck and grooves on the inner wall of the capsule for example, is entirely possible. These means have been developed in the context of the improvement of the objects produced by the method, which is the subject of application WO 97/39953, but they can advantageously be placed on any other type of tube head. Similarly, the various arrangements described above can be made to such heads with the aim of reducing the screwing and unscrewing forces, as well as the annular ring improving the closure security of the capsule, in particular during transport and handling of luggage. .

  The container head according to the invention will be better understood from the description

  detail of a particular embodiment set out by way of nonlimiting example.

  EMBODIMENT OF THE INVENTION - EXAMPLES

  Figure 1 shows a tube head ready for use. The capsule skirt is shown in diametrical section when it was pressed onto the molded head. The user only has to unscrew to uncapping and then distribute the product. The plug formed by the detachment of the cover is

  reusable. To facilitate the observation of this figure, a single skirt lug is shown.

  s Figure 2 shows a head obtained by simultaneous molding with the capsule skirt, the latter being placed so that it forms with

  the lid of an overturned hat. The assembly is shown just after molding and before rupture of the bridges then depression of the capsule skirt.

  o Figure 3 shows a variant of the tube head of Figure 1, requiring less efforts to uncapping, opening and

closure of the capsule.

  EXAMPLE 1 (Figures 1 and 2; Figure 3) Figure 1 shows a sample tube made according to the invention, corresponding to an improvement of the head illustrated in Figure 7 of WO

97/39953.

  In this particular embodiment, the capsule skirt 40 is molded simultaneously with the tube head 1. The cavities 41 are not open, which

  gives the capsule skirt an aesthetic smooth appearance appreciated by users.

  The head 1 has a shoulder 2, one end of which is welded by overmolding to the skirt 500 of the tube. It also includes a neck 3, the base 4 of which is circular cylindrical and the apex is in the form of an axisymmetric nozzle 5. The neck 3 has an annular inner edge which delimits a product dispensing orifice. The annular inner edge is connected by a portion

  tear-off annular 10 at the crown 21 of the cover 20.

  -13 - The plate 30 is located in the extension of the cover 20. It is molded in continuity of material with the latter. The periphery 31 of the plateau is

  circular; it is provided with three latch pins 32 projecting radially, that is to say

  s say projecting radially from the plate by several tenths of a millimeter.

  The capsule skirt 40 is provided on its internal wall 46, near its second end 43, with three non-through cavities 41, of sufficient depth to block the lugs of the lid 32. It also has on the internal wall 46, near the first end 44 of the capsule skirt 40, six skirt lugs 47 of low height, less than two tenths of a millimeter, distributed regularly over the internal wall of the skirt. The cavities 41 are angularly offset by 30 relative to the angular position of the

closest lugs of skirt.

  s15 On the other hand, the neck 3 is provided, on the cylindrical part 4 of its outer wall, with a set of six oblique grooves 71, helical, regularly distributed, separated by inter-grooved reliefs 73 each having a vertex 74 pointed and carrying a circumferential notch 75, intended to trap a skirt lug 47 at the end of screwing. The oblique groove 71 extended by the circumferential notch 75 takes the form of a kind of gamma

  uppercase italic reversed, which gives the appearance of a bayonet mount.

  The circumferential notch 75 has a wall 76 perpendicular to the axis of rotation which counteracts a possible axial withdrawal movement of the lug 47 when the latter is at the level of said notch. It also has a wall 70 parallel to the axis of rotation which serves as a stop for

the closure.

  i ..., ,, '' ,. .. ... 4 - 14- The skirt lugs 47 and the oblique grooves 71 of the neck 3 have been positioned so that after the capsule skirt 40 has been inserted around the periphery 31 of the plate 30 and the trapping of the latch pins 32 in the cavities 41, each skirt lug 47 is engaged in positive engagement in one of the oblique grooves 71 made on the neck 3. It can be seen in particular that the difference Dl between the level S of the upper wall skirt lugs and the level C of the bottom wall of the cavities is greater than the difference D2 between the level E of the entry of the grooves and the level B of the

  o low wall of the lugs.

  The set of skirt lugs occupies six angular positions at 60

  corresponding to the angular positions of the inputs 72 of the grooves 71.

  s Such an angular position of the skirt lugs is very favorable for the

  molding and for sinking the skirt.

  FIG. 2 represents the head after molding: the capsule skirt 40 is molded, separated from the rest of the head by a series of bridges 135 regularly20 distributed over its circumference. The skirt lugs 47 are naturally located in the extension of the bridges 135, between the skirt 40 and the cover 30. The

  neighboring part of bridges 135 thus becomes thicker and makes it possible to break slightly thicker bridges. All this facilitates the flow of the material during molding.

  In addition, as the skirt lugs 47 are as far as possible from the lug lugs 32 and since they have a low height, they can overlap the periphery 31 of the lid 30 when threading and pressing in.

  of the skirt 40 without any blockage or damage.

  - 15- In this example, the notches have a simple shape. It could be possible

  to arrange their design so as to also give them an anti-

  unscrewing. But here the combination of these notches with the forced insertion of the sealing skirt is sufficient for the proper maintenance of the plug in the closed position. FIG. 3 represents a variant of the tube head of this example, where an attempt has been made to reduce the causes of friction between the internal wall of the skirt o of capsule 40 and the external wall of the neck 3, so as to facilitate screwing and unscrewing the capsule thus formed after uncapping. Thus, the inter-groove relief 73 has a high part 78 whose circumferential wall rests on a fronconic shape, the half-angle at the top of the support cone making an angle of 10 degrees relative to the axis of the orifice . The bottom s of the groove rests on a truncated cone whose half-angle at the top is equal to 2.5 O. The maximum depth of the groove is here close to two tenths of a millimeter. The lower part 77 of the inter-groove relief 73 separates the circumferential notches 75 and has a circumferential wall which rests on a cylindrical surface, with a radial height close to two tenths of

  millimeter from the bottom of the grooves.

  In order to reduce the friction forces, the number of reliefs inter-

  grooves 73 has been reduced: one inter-groove relief in two has been replaced by a simple stop stop 79. The skirt still has six lugs 47 in extension of the six bridges 135. Three pairs of them, still being engaged in positive engagement in an oblique groove 71, are guided in their helical movement, so that the rupture of the cover and the screwing takes place in good conditions. The six pins are locked at the end of rotation either by the vertical wall 70 of the circumferential notch 75, or by

a stopper 79.

  To improve the retention of the capsule 40 in the closed position, an annular ring 80 of asymmetrical triangular section is placed on the outer wall of the neck, at the wall 76 of the notches, which is perpendicular to the axis of rotation and serves as a stop for the movement of the pins during a possible axial withdrawal of the capsule. This annular ring 80 has a low radial height, preferably less than that of the inter-groove reliefs 77. Its asymmetrical profile has a slight slope (15 relative to the axis of rotation) oriented upwards (outside of the tube), so that the capsule lugs 47 pass without difficulty over this rod 80 during screwing. The other slope is more brutal and allows to co-sponsor the movement

capsule removal.

  For this sample tube, the skirt diameter is equal to 16 mm, the capsule diameter 12 mm, the diameter of the orifice 2.5 mm, the thickness of the breakable zone 0.2 mm. The uncapping torque is less than 12 Ncm. Of

  even, the closing torque does not exceed 12 Ncm.

  The crossing of the pins over the rod ends with a slight effect

  due to the sudden elastic return of the lugs.

EXAMPLE 2

  The capsule skirt is molded separately from the head. Its external shape is not necessarily cylindrical but its internal wall is cylindrical at least in two places: - 17- * below the cavities, over a length at least equal to the height of the cavities, preferably with guide grooves operculum lugs (in this case, only the bottom of the grooves must rest on a cylinder); * above the capsule lugs, over a length corresponding to the overall height of the inter-groove reliefs, the latter being surmounted by a point as in FIG. 1 so as to facilitate guiding the lugs towards the oblique grooves . This second cylindrical wall preferably has a diameter slightly greater than that of the first wall, so as to

  allow the lugs to pass without friction or damage.

ADVANTAGES

  The tube head according to the invention is inviolable until first use. The capsule skirt and the neck have shapes such that the user sees his gesture guided naturally at first until complete rupture of the rupture zone and detachment of the seal, then when unscrewing the stopper thus formed , finally during multiple reuse of

that same plug.

-18-

Claims (9)

  1. Plastic head (1), which can be fixed on any multidose dispensing packaging container, comprising a neck (3) whose orifice is closed by a cover (20) and mounted in one piece with a closure comprising a capsule skirt (40), said closure being reusable as a cap after rupture of the cover (20), characterized in that the neck (3) is provided with at least three oblique grooves (71) and in that the capsule skirt (40) is provided with lugs (47) on its internal wall (46) and in the vicinity of its first end (44), the number of said skirt lugs (47) being an integer multiple of the number of oblique grooves (71).   2. Plastic head (1) according to claim 1 characterized in that s before uncapping, the pins (47) of the skirt (40) are in positive engagement in the oblique grooves (71).   3. plastic head (1) according to claim 2 characterized in that the difference between the level (S) of the top of the skirt lugs and that (C) of the base of the cavities is greater than the difference between the level ( E) the swelling of the oblique grooves (71) and the level (B) of the base of the lugs.   4. plastic head (1) according to any one of claims 1 to   3, characterized in that the oblique grooves are extended by circumferential notches (75). -19-   5. Plastic head (1) according to any one of claims 1 to   4, characterized in that the outer wall of the neck (3) is provided with a annular ring (80).   s 6. plastic head (1) according to claim 5, characterized in that said annular ring (80) is located at the level of the wall (76) of the circumferential notches (75), said wall (76) being perpendicular to   the axis of rotation and counteracting the axial withdrawal movement of the pins (47).   o 7. Plastic head (1), which can be fixed on any dispensing packaging container, comprising a neck (3) and provided with a capsule comprising a skirt (40), characterized in that the neck (3) is provided with at least three oblique grooves (71) and in that the capsule skirt (40) is provided with lugs (47) on its internal wall (46) and in the vicinity of its first end (44), the number of said pins (47) being an integer multiple of the number of oblique grooves (71), said oblique grooves being   extended by circumferential notches (75).   8. Plastic head (1) according to claim 7 characterized in that   that the outer wall of the neck (3) is provided with an annular ring (80).   9. plastic head (1) according to claim 8 characterized in that said annular ring (80) is located at the wall (76) of the circumferential notches (75), said wall (76) being perpendicular to   the axis of rotation and counteracting the axial withdrawal movement of the pins (47).