GB2065606A - A case for cosmetic products - Google Patents

Abstract

A case especially for cosmetic products comprises a bottom 1, a hinged lid 2 and a locking device comprising a resilient deformable member 5 which is more flexible than the case and is forcibly inserted in a housing formed in the rim 1a of one element 1 of the case, a projection 5a of which member 5 is able to catch behind a projection 4 on the other element 2 of the case. <IMAGE>

Description

SPECIFICATION A case intended, in particular, for cosmetic products and a method of manufacturing it This invention relates to a case intended, in particular, for cosmetic products and a method of manufacturing it.

Cases for cosmetic products, such as powder compacts, rouge cases or the like, intended for wide distribution are sometimes constituted by two plastic portions which are articulated to each other and held in the closed position of the case by a ratchet device.

The ratchet device is generally formed inte graliy and from the same material as the case.

It is known that, to give these cases an aesthetic character, the plastic material used should be relatively hard and rigid (polystyrene, acrylonitrile styrene) with a very smooth and lustrous surface which is agreeable to look at and to touch. This material has fairly high elastic rigidity, and the ratchet device should be produced from this material with elements which are fine enough to avoid having to overcome an excessive force. It is also advisable to create zones which are more elastic for these elements by attenuating their thickness, but this makes them fairly fragile.

Finally, since one portion of these elements is integral with one half of the case and the other porton integral with the other half, dimensional deviations occur during mass production which, during assembly, cause some of the products to have a hard ratchet mechanism while others have no ratchet effect. To the resultant great wastage, there is added the wastage due to breakage of the attenuated elements.

The invention is intended to overcome these disadvantages by proposing, in a case of a hard and rigid material, a device for locking the case in a closed position which makes allowance for dimensional deviations and which provides a locking action with a substantially constant force by means of strong elements.

For this purpose, the invention relates to a case intended, in particular, for cosmetic products, constituted by two plastic portions which are articulated together about a hinge and a device for the mutual locking of the said portions in a closed position situated approximately at the lateral end of the case opposite the hinge and comprising an element integral with one of the said portions which can be elastically ratcheted on an element integral with the other portion. According to one of the characteristics of the invention, one of the above-mentioned elements is constituted by a hook-shaped resilient plastic member, which is more flexible than the case material, joined to one of the above-mentioned portions and capable of co-operating by its free extension with a corresponding hooking surface provided in the other portion.

In a preferred embodiment, the said member is inserted into the rim of one of the said portions and projects beyond a flat terminal surface of this rim forming the closure plane of the case on which a flat terminal surface of the corresponding rim of the other portion rests in the closed position of the case.

The rim of the other above-mentiond portion is advantageously situated beyond the said member relative to the interior of the case, the above-mentioned hooking surface being provided on the internal side of the said rim in such a way that the locking device is invisible in the closed position.

More specifically, the above-mentioned hook-shaped member comprises a thin portion extending opposite the said hooking surface and a solid portion to be inserted into the above-mentioned rim and comprising at least one external rib, which is forcibly driven into a housing provided in the said rim and open at its terminal face.

An advantageous method of inserting this member into the corresponding portion of the case involves, after the moulding of the said portion, introducing the above-mentioned solid portion with a slight force into the said moulded housing during air-cooling of the said portion, complete cooling producing a reduction in the dimensions of the said housing which tightly encloses the said solid portion of the said member.

The invention will be understood better upon reading the following description which is given as a non-limiting example and will permit the advantages and secondary characteristics to be revealed.

Reference is made to the accompanying drawings in which: Figure 1 is a sectional view of the lateral end of a preferred embodiment of case according to the invention provided with a locking device; Figure 2 is a view of an element of the locking device.

The drawings show a case constituted by two portions, a bottom 1 and a lid 2, intended to receive cosmetic products (for example, a block a rouge in a dish-shaped container inside the bottom 1 and a mirror in the lid 2 with an interposed powder-puff). The bottom 1 and the lid 2 are articulated to each other about a hinge (not shown). Each of these portions 1 and 2 has lateral rims la, 2a which are defined by a flat terminal surface 1 b, 2b forming a closure plane 3 when the case is closed (as shown in Fig. 1). The case is locked in the closed portions, on the one hand, by a projection 4 formed on the internal edge 2c of the rim 2a and an insert 5 inserted in the rim 1a and projecting above the terminal surface 1 b thereof.

The projection 4 has an upper surface 4a with which the free end 5a of the hookshaped or similarly shaped member or insert 5 co-operates. When opening the case, for example by parting the gripping edges 6 provided externally on each of the portions 1 and 2, the portion 5a slides off the projection 4 by elastic deformation of the arm 5b, which is only caused if the opening stress is greater than the resistance offered by the arm 5b to this elastic deformation. The same applies to the closure of the case, that is to say for causing the portion 5a to catch above the projection 4.

The member 5 is made of a plastics material having a lower elastic rigidity than the case material, and therefore having a greater elastic deformation capacity. When assembling the two cases elements 1 and 2, the projection 4 can be placed offset to the right or to the left of the figure relative to the position illustrated (which is a theoretical position) owing to possible dimensional deviations of these elements due to manufacturing tolerances. The elastic property of the material of the member 5 allows for these hazards in positioning which are of the order of a few hundredths of a millimetre without allowing excessive variation in the retaining force afforded by the member 5. Mass-produced cases whose closure mechanisms are locked with a substantially constant force are thus obtained.

It will be observed that the member 5 therefore has an arm 5b which is relatively thin, and therefore readily deformable relative to a lower solid portion Sc with which it is inserted into the rim la or, more precisely, in a housing 7 which is open at the surface 1 b and is provided in this rim. This portion Sc has a longitudinal rib 8 so that the width of the portion Sc measured at the tip of this rib is slightly larger than the width of the housing 7 measured in the same direction when the bottom 1 a leaves the production mould.The portion Sc can thus be placed in the housing 7 as the bottom 1 leaves the mould by pressing it with a sR orce, and the assembly is then left to cool in the air, causing a reduction in the dimensions of the housing 7.

This reduction greatly compresses the portion Sc of the member 5 and, in particular, forces its rib 8 to penetrate inside the portion 5c, the force of impaction thus being at a maximum in this region, and opposes, with the utmost effectiveness, the gripping force to which the member 5 is subjected each time the case is opened. It should finally be noted that the locking device 4,5 is invisible when the case is closed, and this is advantageous with regard to the appearance of the case. This quaiity of being invisible is rendered possible by the fact that, in the vicinity of the device 4,5, the rim 1 a is thicker than the rim 2a and the insert 5 can be inserted in the internal side of the rim 2b, the rim 2b extending completely beyond the member 5 relative to the internal volume of the case.

The invention is of value for use in the sphere of packaging and wrapping, in particular of cosmetic products.

It is not limited to the description just given but, on the contrary, covers all the possible variations thereof without departing from the scope or the idea thereof.

Claims (6)

1. A case comprising two portions, a bottom and a lid, which are articulated about a hinge and held in the closed position by a ratchet device situated at the end of the case opposite the hinge, this device comprising a hooking surface on the one portion and an insert made of flexible material fixed in a housing in the rim of the other portion, the hooking surface being a projection formed on the internal side of the rim of the one portion and the insert being constituted by a relatively thick portion comprising a rib which gives it, at the tip of this rib, a width which is greater than that of the housing made in the other portion and a thin arm shaped at its free end to a hook which co-operates with the projection on the one portion.

2. A case as claimed in Claim 1, wherein the hooking surface is on the lid and the housing is in the rim of the case bottom.

3. A method of producing the case according to Claim 1, wherein after moulding of the case bottom, the relatively thick portion of the insert is introduced with a slight force into a housing provided for this purpose in the bottom during the air cooling of the said bottom, complete cooling producing a reduction in the dimensions of the housing which tightly encloses the relatively thick portion of the insert.

4. A case as claimed in Claim 1, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

5. A method as claimed in Claim 3, substantially as hereinbefore described.

6. A case when made by a method as claimed in Claim 3 or 5.