Abstract:
A personal care applicator apparatus seal has a structural element formed of a first material and a sealing element formed of a second material softer or less rigid than the first material. The structural element may have a sidewall with upper and lower ends and inboard and outboard surfaces. The sealing element may be molded to the structural element and may include a first portion circumscribing the sidewall.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Benefit is claimed of U.S. Patent Application Ser. No. 60/649,861, filed Feb. 2, 2005, and entitled “Seal for Applicator for Personal Care Compositions”, the disclosure of which is incorporated by reference herein as if set forth at length. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to personal care. More particularly, the invention relates to applicators for underarm antiperspirant and/or deodorant. 
     A well-developed art exists regarding dispenser/applicators for personal care products. One particular area involves applicators for solid or gel antiperspirant and/or deodorant compositions. Applicators for solid and gel compositions are typically thoroughly similar to each other, with a piston (platform) upwardly movable within a cylinder (barrel) to progressively drive the composition out the barrel upper end. Due to the relative lack of stiffness of many gels, dispensers for such gels commonly include foraminate screen-like applicator elements across the upper end of the barrel. Many solid products, instead have a removable molded seal inserted within the upper end. In manufacture, the seal may serve to mold the composition during a bottom fill operation. At the first use of the product, the end user extracts and discards the seal exposing the upper end of the composition. As molded by the seal, the upper end may have an ergonomically or ornamentally advantageous shape. 
     SUMMARY OF THE INVENTION 
     One aspect of the invention involves a personal care applicator apparatus seal having a structural element formed of a first material and a sealing element formed of a second material softer or less rigid than the first material. The structural element may have a sidewall with upper and lower ends and inboard and outboard surfaces. The sealing element may be molded to the structural element and may include a first portion circumscribing the sidewall. 
     The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a longitudinal median cut-away view of an applicator apparatus. 
         FIG. 2  is a transverse median sectional view of a seal of the apparatus of  FIG. 1 . 
         FIG. 3  is a bottom view of the seal of  FIG. 2 . 
     
    
    
     Like reference numbers and designations in the various drawings indicate like elements. 
     DETAILED DESCRIPTION 
       FIG. 1  shows an applicator  20  having a barrel  22  and a cover  24  in an installed position on a barrel neck  26 . The barrel has a sidewall  27  extending along a central longitudinal/vertical axis  500  from a bottom (base) end  28  to an upper end formed by a rim  30 . A seal  32  is secured across the barrel upper end. A platform or piston  34  supports the composition  35  and is, itself, supported by an actuating mechanism  36  (e.g., a screw-type elevator mechanism) having a user-engagable element such as a knob or wheel  38 . The wheel  38  may be rotated about the axis  500  for progressively raising the platform toward the barrel upper end so as to discharge the composition. The directions are relative and reference typical product orientations in shipping and display. 
     The seal  32  includes a dome  40  having a doubly concave lower surface or underside  42  molding a doubly convex upper surface  44  of the composition  35 . The dome  40  extends upward through a sidewall  46  having an outboard surface  48  in sealing contact with the inboard/interior surface  50  of the barrel near the upper end. The seal further includes a flange  52  at the upper end of the sidewall  46  having an underside engaging the rim  30 . 
     As heretofore described, the apparatus  20  may be of any of a wide variety of known or yet-developed configurations.  FIG. 2 , however, shows further details of the exemplary implementation of the seal  32  as a two-shot molded product. The seal includes a first element (e.g., a single piece)  60  principally serving a structural purpose and a second element (e.g., a single piece)  62  principally serving a sealing purpose. In exemplary manufacturing processes, the first piece  60  is initially molded in a first mold and then transferred to a second mold where the second piece  62  is overmolded to the first piece  60 . The first piece  60  may be formed of a relatively rigid material (e.g., polypropylene). The second piece  62  may be formed of a material that is relatively soft and/or flexible and/or has a relatively high stiction property (e.g., a thermoplastic elastomer (TPE)). The softness and/or stiction of the second piece  62  provide an advantageous engagement with the barrel inboard surface  50 . The compliance and stiction may help sealing and improve retention compared with a unitary seal formed from a more rigid and/or less sticky material. The first piece  60  includes a sidewall  64  having a lower end  66  and an upper end  68 . A dome  70  extends upward from the lower end  66  and may extend above the upper end  68 . A flange  72  extends outward from the sidewall at the upper end  68 . An outboard portion of the flange  72  forms the seal flange  52 . 
     The second piece  62  includes a first portion  74  circumscribing the sidewall  64  up to the underside of the flange  72 . A second portion  76  depends from the first portion  74  and below the sidewall lower end  66 . In the installed condition of  FIG. 1 , the outboard surface of the first portion  74  is in sealing contact with the barrel inboard surface  50  and forms an outer portion of the seal sidewall. The outboard surface of the second portion  76  may be tapered to guide insertion during installation of the seal into the barrel. 
     In the exemplary seal, the first piece  60  is molded with a channel  80  in the inboard/interior surface or underside  82  of the dome  70 .  FIG. 3  shows the exemplary channel  80  as having a central enlarged portion  84  (e.g., of a circular planform). A pair of narrower straight portions  86  of the channel  80  extend from the enlarged portion  84  all the way to the sidewall lower end  66 . In the overmolding of the second piece  62 , the overmolding fills the channel  80  with a third portion  88  of the second piece  62  spanning between opposite ends of the second portion  76 .  FIG. 3  shows the seal having an exemplary ellipse-like planform namely, it has symmetry across medial and transverse vertical planes  510  and  512  (or lines when viewed in section or plan), is longer along one of those two directions, and has a continuously curving concave interior. If a true ellipse, the semi-minor axis and semi-major axis would fall along the planes  510  and  512 , respectively. In the exemplary implementation, the channel  80  may serve to guide a flow of the material forming the second piece  62 . For example, the material may be centrally introduced within the channel portion  84  and flow outward. 
     In the exemplary seal, the interior surface of the second piece third portion  88  and the interior surface of the second piece second portion  76  combine with the first piece interior surface  82  to form a smooth continuously curving doubly concave surface  42  for molding a complementary doubly convex upper surface  44  of the composition. 
     In the exemplary seal, the first piece  60  has a structural fin  100  extending along a major portion of the length of the dome  70  and protruding from its outboard surface. The fin  100  may serve one of several functions. First, during the molding of the first piece  60 , the fin may be an artifact of passageways in the mold for introducing the first material. This, for example, may leave the fin with gate artifacts  102 . Additionally, the fin  100  may provide the end user with an easy grasping portion to pull and pry off the seal. 
     One or more embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, the principles may be applied in a redesigning/engineering of any of a variety of existing applicators or in the design/engineering of yet new applicators. Accordingly, other embodiments are within the scope of the following claims.