Abstract:
A double-walled plastic jar for cosmetic materials, having an inner compartment to hold the cosmetic, and an annular outer side wall defining the exterior of the jar. The inner compartment carries the lip that seals with a screw cap, and also carries an external skirt, which latter has the screw threads for engagement by the cap. In addition, a weight is disposed in a-concealed manner in the base of the jar, between the walls, to give the jar a heft feel, characteristic of glass or thick plastic walls.

Description:
TECHNICAL FIELD 
       [0001]    The invention relates to a container assembly of thin/economically produced parts which simulate an image and weight of an expensive cosmetic jar. 
       BACKGROUND ART 
       [0002]    There have been many styles of plastic double walled containers devised over the years. For high-end cosmetic products, normally a single piece glass or plastic jar with a very thick wall cross section has been preferred. The objective was to offer a feeling of quality and heft. However, molding these thick walled jars in plastic is expensive, due to both the high volume of expensive resin, and the long molding machine cycle time. 
         [0003]    A double walled container is typically made of two assembled parts; an inner cup, which serves as a vessel for the product when sealed with a cap, and an outer cosmetic jar part, which is shaped to look like a cosmetic jar body. A threaded closure or cap would normally engage a threaded portion of the jar, allowing the contents to remain sealed until opened by the consumer. 
         [0004]    The use of clear plastic to create the outer wall of a typical double walled container usually allows any mechanical fitment means/features between the inner and outer parts to be visible by the consumer, which removes the image of quality and prestige the customer wants to convey in their packaging. With the use of a threaded closure and threaded neck form on a jar, any assembly of individual components to create this must be able to withstand the normal torque and axial forces associated with these types of features during filling and use. The use of clear Styrenic and Acrylic resins for the threaded portion of the jar for products containing volatiles or fragrance oils can lead to chemical compatibility issues and subsequent package failures, like stress cracking under load. 
       DISCLOSURE OF INVENTION 
       [0005]    This invention offers a new and unobvious solution to the problem of clear cosmetic jar parts and the accompanying visibility of unsightly mechanical securements needed to assemble them. With the invention, such mechanical securements are desirably positioned completely inside of the jar neck area. In cases where the use of an opaque resin for the threaded jar liner, there is obscured the consumer&#39;s view of the mechanical securements needed to fasten the parts together. 
         [0006]    Due to the placement of these securements within the neck area, the typical shoulder area of a common cosmetic jar can then be formed in the outer clear part. Visually, this is much more appealing than seeing mechanical securements within the shoulder area. The clear, unbroken shoulder area conveys a desired look and feel of a high end glass jar. 
         [0007]    The invention provides a plastic jar for cosmetic materials, said jar being adapted to receive a screw cap, and said jar comprising, in combination a substantially annular inner side wall and a transverse bottom wall formed integrally therewith, said walls defining a compartment to hold the cosmetic material, a substantially annular outer side wall defining an exterior of the jar, said annular inner side wall having an upper lip for sealing engagement with the screw cap, an exterior skirt integrally formed with said lip, said skirt being spaced from said annular inner side wall and provided with screw threads on its exterior surface, for engagement by the screw threads of said screw cap, said outer annular side wall having an upper lip, said upper lip of the annular inner side wall and skirt forming a downwardly facing groove to receive the upper lip of the annular outer side wall, said latter upper lip extending into said groove to an extent whereby it directly underlies the screw threads of the skirt, and anti-rotation means on a wall of the groove and on the upper lip of the annular outer side wall, operative to prevent inadvertent rotation or shifting between the annular inner side wall and the annular outer side wall. 
         [0008]    Other features and advantages will hereinafter appear. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a vertical section of the double-walled jar of the invention as assembled. The jar comprises an annular inner side wall and an annular outer side wall, as well as a bottom plug connected to both walls. 
           [0010]      FIG. 2  is an exploded view of the components of the jar of  FIG. 1 . 
           [0011]      FIG. 3  is a view like  FIG. 1 , except prior to assembly of the bottom plug of the jar to the annular walls thereof. 
           [0012]      FIGS. 4 ,  5  and  6  are detail views, respectively, of the construction of portions of the jar of  FIG. 1 . 
           [0013]      FIG. 7  is a perspective view of the jar of  FIG. 1 , except with a broken-away area, showing the cooperation of the threads of the jar with the underlying outer annular wall. 
           [0014]      FIG. 8  is an exploded view of the jar of  FIG. 1 , and further including a screw cap therefor, constituting a jar lid. 
           [0015]      FIG. 9  a perspective view of the annular outer side wall per se. 
           [0016]      FIG. 10  is a view like  FIG. 1 , of a modified double-walled jar and wherein the bottom wall is integrally molded with annular side wall of the jar. 
           [0017]      FIG. 11  is a front elevation of a further modified jar having a polygonal outer annular wall as opposed to the cylindrical configuration shown in the previous figures, and 
           [0018]      FIG. 12  is a section on the line  12 - 12  of  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0019]    The present invention comprises essentially several separate thin-walled plastic components which are fitted together to form a double-walled jar. The jar is intended to hold a quantity of cosmetic product (not shown), and at the same time, impart to the consumer, a heft or solid feel to the jar, simulating that of thick walled plastic, or else high quality molded glass. 
         [0020]    Referring now to  FIGS. 1-6 , there is shown in section, and fragmentary section, the inner member or compartment of the jar, comprising an annular inner side wall generally designated by the numeral  10 , having a transverse bottom wall  12 , and an annular outer side wall  14 . Connected to the annular outer side wall  14  is a bottom plug  16  held in place by a retainer structure to be described below. The annular outer side wall  14  and bottom plug  16  thus define the exterior of the jar. 
         [0021]    In accordance with the invention, the annular inner side wall  10  extends upwardly to a lip  18 , which is intended to seal against a liner  20  of a screw cap  22 , the latter being shown in the view labeled  FIG. 8 . Connected integrally with the lip  18  is a downwardly extending annular skirt  24 , the skirt  24  and outer surface of the lip  18  forming a downwardly facing groove  26 ,  FIG. 2 . Screw threads  23  are also provided on the skirt&#39;s outer surface, as shown. By the invention cooperable anti-rotation structures comprising shoulders  28  ( FIG. 7 ) on the side wall of the groove  26  and cooperable shoulders  30  on the annular outer side wall  14 , are arranged to engage one another, being operative to prevent relative turning movement between the compartment defined by the walls  10  and  12 , and the annular outer side wall  14 . In practice the shoulders  28  and  30  are constituted as vertical ribs. The upper part of the annular inner side wall  10  has an external shoulder  32  which is engaged by the bottom edge of the skirt  24  as the latter becomes fully seated thereon. Optionally, cooperable retainer means in the form of a bead and groove formation  33 ,  FIG. 4 , on the skirt  24  and on the annular outer side wall  14  at the external shoulder  32  thereof, are provided for increased strength and stability. 
         [0022]    In accomplishing the securement of the plug  16 , the latter is provided with an upstanding skirt  34 ,  FIG. 6 , which is arranged to mate with a similarly-sized downwardly extending skirt  36  at the junction of the annular inner side wall  10  and transverse bottom wall  12 . On the outer surface of the skirt  34  is a further retention arrangement involving cooperable bead/groove formations  38 , which function to retain the bottom plug  16  in position. Preferably the plug  16  is snapped into the opening at the bottom of the annular outer side wall  12 . The plug  16  can have a recess  42  to receive a label or appliqué (not shown), that can contain advertising material or instructions relating to the product contained in the jar. 
         [0023]    Further by the invention, the upstanding skirt  34  of the plug  16  has, on its inner surface  44 , a resilient or crushable formation  46  ( FIG. 2 ) of plastic material, and a weight  48  which operates to give the jar a heavier feel, similar to that of thick plastic or glass. The weight  48  is in the form of a disk, and is held in place by being pressed into the well formed by the skirt  34 , and crushing the plastic as it is forced into place. The resilience of the crushed plastic retains the weight in position in the plug  16 , and prevents it from inadvertently shifting or rattling in the completed jar. 
         [0024]    With the present invention there is realized an improved stability in the area of the screw threads. Preferably, the plastic utilized is polypropylene. Polypropylene has the advantage of low cost and chemical compatability requirements with the enclosed cosmetic product. The use of polypropylene for the lip and skirt areas circumvents any tendency toward stress cracking under load, and its use is a major advantage over the use of styrenics or acrylics in place of the polypropylene. 
         [0025]    Further, by virtue of the provision of the interengaging shoulders  28  and  30 ,  FIGS. 7 and 9 , which are disposed radially underneath the screw threads  23 , forces encountered during screwing or unscrewing of a screw cap  22  are countered by the immediately-adjacent shoulders  28 ,  30 , and the resulting construction also provides the high resistance to stress cracking noted above, especially with certain cosmetic solvents, and after the plastic adjacent the screw threads has aged an extent. 
         [0026]    Another embodiment of the invention is illustrated in  FIG. 10 , showing a slightly modified double walled jar  60 . The construction involving retention of the inner and outer side walls  62  and  64  respectively, is essentially as described above. The increased strength of the skirt  66  is also retained in the present construction. 
         [0027]    By the invention, a weight  68  is fitted into the downwardly extending skirt  70  on the bottom wall  72  and held therein by a bead  74 , or by suitable cement. 
         [0028]    In this embodiment the exterior of the jar is defined by the annular outer side wall  64  and an integral bottom wall  78 . The appearance from the exterior would be the same as that of a normal heavy walled jar. The weight would be hidden from view by the skirt  70 , or by a label applied to a very shallow recessed portion  82  in the underside surface  80  of the jar exterior. The provision of the weight  68  gives this jar the same hefty feel as a high-end container product. By using a blow molded exterior, typical uniform wall thickness jar shapes can be created, moreover of a type not heretofore achievable for use in a straight pull design. 
         [0029]    One additional embodiment is illustrated in  FIGS. 11 and 12 , wherein the structural details are generally the same as those of the embodiment of  FIG. 1 , except that the outer wall is not cylindrical, but instead polygonal. The area above the neck is round, to accommodate the usual screw cap, as before. In other respects this version is similar to  FIG. 1 . It is understood that with the present arrangement, almost any geometrical configuration can be used for the outer wall. 
         [0030]    From the above it can be seen that we have provided a novel and improved jar construction which is both simple in its structure and economical to manufacture. The look and feel of high-end jars is retained utilizing essentially solely thin plastic components. The parts are assembled to produce in a unique manner, concealment from view from outside the jar, of structural parts involved with their retention of the jar in its assembled position. Finally, the overall integrity of the construction and the elimination of possible failure from cracking of the plastic, or degradation from contact with cosmetic chemicals is achieved. 
         [0031]    The disclosed containers are thus seen to represent a distinct advance and improvement in the field of closures and cosmetic storage and dispensing. 
         [0032]    Each and every one of the appended claims defines an aspect of the invention which is separate and distinct from all others, and accordingly it is intended that each claim be treated as such when examined in the light of the prior art devices in any determination of novelty or validity. 
         [0033]    Variations and modifications are possible without departing from the spirit of the claims. 
       LISTING OF REFERENCE NUMERALS 
       [0000]    
       
           10  Annular inner side wall 
           12  Transverse bottom wall 
           14  Annular outer side wall 
           16  Bottom plug 
           18  Lip 
           20  Liner 
           22  Screw cap 
           23  Screw threads 
           24  Annular skirt 
           26  Groove 
           28  Shoulders or vertical ribs on wall  10   
           30  Cooperable shoulders or vertical ribs on skirt  24   
           32  External shoulder 
           33  Bead/groove 
           34  Plug&#39;s upstanding skirt 
           36  Downwardly extending skirt 
           38  Bead/groove 
           42  Recess in plug 
           44  Inner surface of upstanding skirt 
           46  Crushable or resilient plastic projection 
           48  Weight 
           50  Groove/bead 
           52  Groove/bead 
           54  Interengaging groove/bead formation 
           56  Interengaging groove/bead formation 
           60  Modified jar 
           62  Annular inner side wall 
           64  Annular outer side wall 
           66  Skirt 
           68  Weight 
           70  Depending skirt 
           72  Bottom wall 
           74  Bead 
           76  Annular outer side wall 
           78  Integral bottom wall 
           80  Underside surface