FR2516058A1 - Stopper for aerosol container - has skirt shaped capsule with annular joint compressed radially by forced fitted ring - Google Patents

Abstract

The stopper is for the neck of a receptacle with a product under pressure. It is a skirt shaped capsule and sealing is provided by an annular joint (12) in a peripheral groove (15) in the larger outer diameter of the neck (3). The joint is compressed by radial contraction of the skirt (8). The groove (15) depth is roughly equal to the radial width of the joint (12). Radial contraction of the skirt is given by a ring (16) forming a hoop, forced in axially. The capsule base has a groove for the neck top edge (10).

Description

CONTAINER NUT SHUTTERING DEVICE
POTIER PRESSURIZED PRODUCTS
The device for closing the necks of containers for pressurized products such as aerosol cans is frequently constituted by a shutter in the form of a skirted capsule, the lower edge of which is crimped on an additional thickness in the form of an elongated cylindrical ring. The FR patent. 2 155 806 gives an example of such a closure device adapted to an aerosol can which comprises a dispensing valve.

Let the neck end with a rolled edge, as shown on the
US. 3,196,819, or by an extra thickness in the form of an elongated ring, as shown in FR. 2 155 806, the seal between the container and the obturator is most often ensured by a flat annular seal tightened between the rounded upper edge of the neck and the obturator.

The neck and the neck of metal containers are generally formed by several axial stamping passes, as described in the US.

3,196,819 and FR. 2,155,806. The first passes shrink the upper part of a cylindrical blank to give a dome-shaped neck to the upper part of the container. The following passes return the upper edge of the dome outward to give the neck a shape of a rolled edge or an elongated ring called a carnette, a tale represented in the FR. 2 155 806. The contraction of the cylindrical blank to obtain the dome leads to the formation of longitudinal folds on the internal surface of the cage. These folds which continue radially on the upper edge of the neck are very harmful to a good seal.

As explained inter alia in FR. 2 264 722, this sealing problem is usually remedied by making a countersink, that is to say a surface dressing of the upper part of the upper edge of the neck, at the location where the seal is to be applied. .This machining however has various disadvantages - it is an additional operation in the manufacturing cycle, its
cost is not negligible; - the wall of the rolled edge is thinned at the precise location which must
withstand a vertical force of the order of 50 to 100 kg during mid
in place and compression of the joint - the woolen fabric removes not only the metal but obviously the layer
varnish which protects the metal from corrosion
contained product - the seal must be positioned and compressed with great precision
to avoid any product infiltration down to the bare metal.

The shutter device, object of the invention, solves these various problems. In this device, the seal between container and obturator is ensured not by a flat seal applied to the upper part of the neck, but by an annular seal which is arranged in a peripheral groove on the external lateral surface of the larger diameter of the neck. The radial thickness of the seal is preferably substantially equal to the depth of the groove, this thickness having to allow a radial contraction of the seal, of the order of 20 to 30 t during the fitting of the obturator on the bottleneck.

The seal is preferably an O-ring with a circular section, a shape currently widely used in the industry.

To improve the positioning of the shutter on the neck, its bottom can be provided with a circular rib which is applied to the upper surface of the neck, preferably on the part inclined inward.

One can, moreover, provide two concentric ribs which are placed astride the upper edge of the neck. These ribs ensure in good time a good installation of the shutter and an additional seal which limits the contact of the product contained with the seal as well as with the external surface of the neck.

The invention will be better understood from the following description of examples of sealing devices for containers intended for pressurized products as well as by examining the appended figures.

FIG. 1 represents, in axial section, the upper part of a container for pressurized product, the neck of which is closed by a device of the prior art; the seal between the neck of the container and the obturator is ensured by a flat annular seal.

2 shows, in axial section, another container closed by a device according to the prior art. Sealing is ensured by an annular O-ring.

Figure 3 shows a fairly similar container, but closed by a device according to the invention, the shutter is made of plastic.

Figure 4 shows, in axial section, a similar container closed by a shutter whose skirt is metallic.

FIG. 5 shows, in axial section, a similar container closed by another shutter with a metallic skirt.

In FIG. 1, the upper part of an aerosol can is seen, the dome (2) and the elongated neck (3), commonly called "bag", were produced from a cup-shaped blank cylindrical according to the technique described in the FR. 2 155 806. The upper portion of the cylindrical blank was first constricted by several passes of axial stamping according to the technique described in the US. 3,196,819, then the upper edge of the dome (2) was then turned outwards by other master stamping passes according to the technique described in FR.

2 155 806. It can be seen that the neck (3) has an elongated shape similar to a glass ring of thickness E with an external surface of cylindrical shape over a height H. Its upper edge (10) is generally laminated.

The shutter shown (4) is a composite shutter consisting of a metal capsule (5) often called a cup and a plastic valve (6). The metal capsule (5) essentially consists of a flat bottom (7) in the center of which the valve (6) is fixed and a cylindrical skirt (8) of dimensions corresponding to those of the cylindrical part of the neck (3) . The seal between neck (3) and obturator (4) is ensured by a flat annular seal (9) compressed axially between the rounded upper edge (10) of the neck and the bottom (7) of the capsule (5). The fixing of the capsule (5) on the neck is ensured by crimping the lower edge (11) of the skirt under the cylindrical part of the neck (3).

FIG. 2 represents the upper part of an aerosol can closed by a shutter (4) similar to the previous one. Sealing is here ensured by an O-ring (12). Its radial thickness (e) is equal to its measured thickness - axially. It is compressed against the lower part of the neck by crimping the lower edge (11) of the skirt (8) against the lower part of the neck (3) of thickness E.

Seals of this type are shown in Figure 5 of C1 1 931 463.

The O-ring (12) is housed under the widened part of the neck. Its installation is relatively difficult because it must be radially expanded, of appreciably the value E, to cross the thickest part of the neck. It must, then, retain sufficient elasticity to be properly pressed into the throat below the neck. The position of the O-ring (12) is not clearly defined. It can be placed, as shown in Figure 2, on the rounded lower end of the neck surface. It can also descend lower below the lower rim (13) of the neck, and come to be pressed against this rim (13) with sharp edge, which can shear it during crimping. To avoid the risk of shearing of the seal (12), it is possible to turn the flange (13) of the neck inwards, similar to the shape shown in FIG. 1, while pressing this rounded lower flange (14) against the neck of the case. The compression of the seal (12) is then poorly defined during crimping, in which case the seal can be pushed upwards in the acute gap between the neck of the container and the lower edge (14) of the neck (3).

Figure 3 shows a sealing device according to the invention.

The seal between the container (1) and the shutter (4) is ensured by an O-ring (12), disposed in a peripheral groove (15) located halfway up the external lateral surface of the neck (3). The shutter (4) is here made of plastic. The skirt (8) of the shutter is contracted radially on the seal (12) and the neck (3) by a ring (16) forming a hoop, which slides axially along arrow F for its positioning. The skirt (8) and, consequently the shutter (4), is blocked axially by inclined bosses (17) which come to apply under the lower edge of the neck (3). Concentric grooves (1819) at the bottom (7) of the capsule interlock on either side of the upper edge (10) of the neck. The depth of the groove (15) is substantially equal to 0.8 e, which allows the joint thickness to contract by around 20 t.

Figure 4 shows another alternative embodiment of the device according to the invention. As in Figures 1 and 2, the shutter (4) is composite, consisting of a metal casing (5) and a plastic valve (6). The seal is ensured by an O-ring (12), as in the previous case. The metal skirt (8) is contracted radially on the joint (12) not by a concentric hoop, but by a regular lateral crimping. Its lower edge (11) is folded over the lower edge (14) of the cylindrical part of the neck (3). The depth of the groove (15) may be slightly greater than the thickness e of the seal (12).

This allows the seal (12) to be placed precisely in a housing of defined dimensions at a well determined location. For its installation, it is enough to dilate it A value 2 e instead of 2 E.

FIG. 5 represents another alternative embodiment, the metal skirt (8) has a height less than the total height of the neck (3). Its lower edge (11) descends little below the groove (15). It is not folded down below the lower edge (14) of the neck, but contracted strongly on the seal (12) at the level of the groove (15).

The production of the necks (3) according to FIGS. 3, 4 and 5 is very easy. First, a neck with a high flap like that of FIG. 1 is produced, this by successive stampings according to the process described in the FR. 2,155,806.

Lamination of the upper edge (10) of the neck is unnecessary. The peripheral groove (15) is easily produced on the external cylindrical part of height H of the neck, this by an external knurling pass. This knurling pass compresses and smoothes the longitudinal folds which may appear on the external cylindrical part of the neck, without removing any material and therefore varnish. Moreover, if, as a result of surface defects, the dial prints a few folds or scratches on the surface of the neck, these folds or scratches will be horizontal, perpendicular to the direction of any product leaks. They can only improve the seal. These folds or scratches being made without removing metal or varnish, are not primers of corrosion.

The O-rings (12) have a thickness e of the order of 1.5 zm. They are easily placed in the groove (15) which assigns them a very precise position. One can use for the joint (12) more rigid and less elastic materials than those required by the joints of figure 2 where, after having crossed the widened part of the neck of diameter D + 2 E, the joints (12) must return press against the neck of the container of diameter substantially D; In the device according to the invention, the fitting of the seal requires its radial expansion of the order of its own radial thickness, instead of the thickness E of the neck. The pressure exerted on the seal (12) by the capsule does not is not distributed over the entire width of the upper edge (10) of the neck as in the flat seal in FIG. 1, but mainly concentrated on the equatorial plane of the O-ring (12).

Thus, in the device according to the invention, the O-ring (12) is easier to put in place than in the solution of FIG. 2. It suffices a groove (15) of shallow depth p, of the order the radial thickness of the joint. The O-ring (12) does not need, for its installation, to be greatly expanded by the entire thickness E of the neck, as in the case of FIG. 2. It is then compressed, during crimping, by a regular contraction of the cylindrical part of the skirt (8), without risking being damaged by the crimping of the bottom of the skirt (8) which transforms a cylindrical shape into a conical shape, as shown in Figure 2, which may cause wrinkles detrimental to sealing.

It will be noted that, in the case of a shutter with a skirt (8) made of plastic material similar to the shutter shown in FIG. 3, the contraction of the skirt can be easily obtained by using a heat-shrinkable material for the skirt which is heated. in good time. This avoids mechanical traction by a hoop ring (13).

Finally, it should be noted that the device which is the subject of the invention can also be used for the necks of glass or plastic containers. The only condition is that a peripheral groove (15) is provided substantially at mid-height of the outer lateral surface of larger diameter of the neck.

In all cases, the neck (12) is well positioned and sheltered. In a groove (15) of depth substantially equal to its own thickness e. It is not moved when the shutter is put in place.

The pressure P of the product contained in the container itself contributes to compressing the seal between the neck (3) and the skirt (8) of the capsule.

Claims (8)

10 / - Device for closing the neck of a container for a pressurized product such as an aerosol can by a shutter in the form of a capsule with skirt, characterized in that the seal between neck and capsule is ensured by an annular seal (12) arranged in a perishic groove (15) of the external lateral surface of larger diameter of the neck (3). 20 / - Device according to claim 1, characterized in that the annular seal (12) is compressed by radial contraction of the skirt (8) of the capsule.  3 / - Device according to any one of claims 1 or 2, charac terized in that the depth p of the groove (15) is substantially equal to the radial thickness of the seal (12). 40 / - Device according to any one of claims 2 or 3, characterized in that the radial contraction of the skirt (8) is provided by a ring (16) forming a hoop axially fitted force. 50 / - Device according to any one of claims 1, 2, 3 or 4, characterized in that the bottom (7) of the capsule comprises at least one groove coming to fit on the upper edge (10) of the neck.  6 / - Device according to any one of claims 1, 2, 3, 4 or 5, characterized in that the height of the skirt (8) of the shutter is less than the total height of the neck. 70 / - A method of producing the device according to claim 2, ca characterized in that a) a container is made using a known method, the neck of which com  wears a peripheral groove (15) on the lateral surface of its groove  lot (3), b) an annular seal (12) is put in place in the groove (15), c) a shutter is put in place on the neck and the seal  from capsule to skirt (8), d) the skirt (8) of the capsule is contracted on the seal (12) and the  neck (3) by a known method. 80 / - Method according to claim 4, characterized in that the skirt (8) is contracted on the joint (12) and the neck (3) by fitting a ring (16) forming a hoop. 90 / - Method according to claim 4, characterized in that one contracts the skirt (8) on the joint (12) and the neck (3) by heating a skirt (8) of shrinkable material. 100 / - A method according to claim 4 characterized in that one contracts the skirt (8) by crimping with the wheel.