Abstract:
A reduced cost interconnection for shaving razor cartridges. A base member is injection molded as a single continuous mass. The base member defines at least one void that may receive a mass increasing member. The base member has a handle portion integrally formed with a living hinge and an interconnection feature. The interconnection feature is biased to detachably engage a counterpart interconnection feature of a blade cartridge. Elastomeric reinforcement in over molded onto the base member to improve the structural integrity of the living hinge.

Description:
[0001]    This application is a continuation of pending U.S. patent application Ser. No. 14/221,086 filed Mar. 20, 2014 entitled “Shaving Razor Interconnection Mechanism and Method of Making Simplified Interconnection.” 
     
    
     BACKGROUND 
       [0002]    1. Field 
         [0003]    Embodiments of the invention relate to shaving razors. More specifically, embodiments of the invention relate to shaving razors with a simplified cartridge interconnection feature. 
         [0004]    2. Background 
         [0005]    Many shaving razors with different handle formations exist. Some disposable razors without a replaceable blade cartridge have molded handle bonded to or formed as part of head into which one or more blades may be inserted. Such disposable razors are generally regarded as providing an inferior shave to razors with replaceable blade cartridges. The manner in which cartridges connect to the handle influences both manufacturing costs and shave quality. The existing razors generally use quite complex interconnection mechanisms typically involving numerous parts including springs, hooks, release buttons that are all discreetly formed and require separate manufacture and assembly. This increases the cost and complexity of the manufacturing process. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that different references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one. 
           [0007]      FIG. 1  is an exploded view of a razor of one embodiment of the invention. 
           [0008]      FIG. 2  is a sectional exploded view of the razor of  FIG. 1 . 
           [0009]      FIG. 3  is a sectional view illustrating the interconnection according to one embodiment of the invention. 
           [0010]      FIG. 4  is an exploded view of an alternative embodiment of the razor handle. 
           [0011]      FIG. 5  is a cutaway view of a razor handle with the embodiment of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0012]      FIG. 1  is an exploded view of a razor of one embodiment of the invention. A base member  102  is unitarily injection molded from a suitable thermoplastic. Suitable thermoplastics include resins having sufficient rigidity once cured to limit flexion of the handle such that good control of a razor cartridge attached thereto can be maintained. One suitable thermoplastic is glass fiber-impregnated nylon with a glass fiber content of 10-30% by weight of the mixture. This thermoplastic has been found to have suitable strength and rigidity characteristics to form a base layer for one embodiment of the instant invention. 
         [0013]    Base member  102  defines one or more interior pockets  116  to receive mass increasing members  106  that increase the weight of the handle and therefore improve the tactile sensation for a user. In one embodiment, the pockets  116  are sized such that the weights retain the weights in a pressure fit relation such that the wall or ends of the pockets exert a force on the weight  106  to retain it with in the pocket. In one embodiment, the weights are inserted into the pockets after the base member  102  is injected and cured. In an alternative embodiment, the combined weights  106  and base  102  are formed by insert molding. While in the shown embodiment, three internal pockets  116  (and three weights  106 ) are present, other configurations of weights and pockets are within the scope and contemplation of the invention. Base member  102  also has formed as a part thereof, in the single molding operation, an interconnection feature  112  formed to engage a blade cartridge. Interconnection feature  112  is described in greater detail with respect to  FIGS. 2 and 3  below. 
         [0014]    In one embodiment, elastomeric reinforcement  104  is over molded onto base member  102  in a second injection during manufacture. The elastomeric reinforcement  104  improves the tactile sensation experienced by a user holding the razor and supports the interconnection feature  112  to reduce the risk that it becomes permanently deformed during use. Additionally, the elastomeric reinforcement  104  provides additional retention of weights  106  within pockets  116 . It is preferred that weights  106  pressure fit into pockets  116  so that the elastomeric reinforcement is not the sole retaining feature, but the pressure fit is not essential to all embodiment of the invention. 
         [0015]    A cartridge  108  includes a plurality of shaving blades that form part of a blade head. The blade head is coupled to an injection-molded yolk having a male member  118  extending therefrom. Male member  118  defines a recess  128  that can receive interconnection member  122 . The shape and construction of the head can have myriad different forms including those described in copending application Ser. No. 13/173,911 or U.S. Pat. No. 8,479,398. The cartridge interconnection features, the male member  118  with defined recess  128 , are independent of the form of the head. 
         [0016]    Elastomeric reinforcement  104  is selected from a group of thermoplastic elastomers (TPE&#39;s) having favorable adhesive qualities relative to the thermoplastic selected for the base member. In one embodiment, the elastomer TC5PAZ available from Kraiburg TPE Corporation is selected. During manufacture the TPE is injected at high temperature, which improves the bonding characteristics with the base member  102 . In addition to the natural adhesion between elastomeric reinforcement  104  and base member  102 , base member  102  may define interstial voids into which the elastomeric resin flows during manufacture. The cured resin then further acts as an anchor within those interstial voids to prevent delamination of the elastomeric reinforcement  104  from base member  102 . 
         [0017]      FIG. 2  is a sectional exploded view of a razor of one embodiment of the invention. Base member  102  is shown with mass increasing members  106  residing in pockets therein. Additionally, a female receiver  232  defined by base member  102  can be seen. Female receiver  232  is dimensioned to receive male member  118  of blade cartridge  108 . Interconnection member  112  includes a living hinge  212  and a tine  222 . Living hinge  212  is manufactured to bias tine  222  into female receiver  232  such that when male member  118  is inserted into the female receiver  232  the tine  222  engages (seats within) recess  128 . 
         [0018]    Elastomeric reinforcement  104  includes a living hinge reinforcement portion  214  that supports the interconnection member  112 . Portion  214  increases the bias of living hinge  212  into female receiver  232 . Portion  214  also reduces the risk that living hinge  212  will move beyond the elastic region of the underlying material into the plastic region resulting in permanent deformation. It has been found that this construction allows the living hinge to endure thousands of cycles without breakage. 
         [0019]    While in one embodiment, the living hinge  212  is supported by the elastomeric reinforcement portion  214 , in other embodiments, other resilient members could be used. For example, a spring may reside in a spring housing that is molded as part of the base member. In one embodiment, the spring would reside forward of the living hinge and bias it toward the female receiver. In this context “forward” of the living hinge is deemed to mean the direction closer to the head end of the handle. The spring hosing may be sealed with a snap fit cover. Generally, the selected resilient member how ever constituted exerts a bias force on the living hinge as described and also helps to prevent permanent deformation of the interconnection member. 
         [0020]      FIG. 3  is a sectional view illustrating the interconnection according to one embodiment of the invention. In this figure, elastomeric reinforcement member  104  is shown residing on base member  102 . Interconnection feature  112  with its living hinge  212  can be seen with its tine  222  extending into female receiver  232 . Interconnection reinforcement portion  214  is shown supporting living hinge  212  and the remainder of interconnection feature  112 . When male member  118  of blade cartridge  108  is inserted into female receiver  232 , living hinge  212  flexes to allow the leading edge of male member  118  to pass and then the bias force of living hinge  212  and reinforcement portion  214  bias the tine into engagement of recess  128 . Blade cartridge  108  is then locked in place and ready for use. To remove the blade cartridge the user need merely apply force to interconnection feature  112  to overcome the bias force of living hinge  212  and reinforcement portion  214  to release the cartridge  108 . 
         [0021]      FIG. 4  is an exploded view of an alternative embodiment of the razor handle. In this embodiment, base member  402  defines a single pocket  426  to receive mass increasing member  406 , pocket housing  436  provides additional structural support for weight  406 . Weight  406  is pressure fit into pocket  426  after the molding of base layer  402 . In one embodiment, weight  406  can be inserted directly into pocket  426  from the bottom side of member  402 . After insertion the elastomeric reinforcement layer  404  is over molded onto base member  402 . Interconnection feature  412  of base member  402  is identical to the analogous feature described with reference to  FIGS. 1-3 . 
         [0022]      FIG. 5  is a cutaway view of a razor handle with the embodiment of  FIG. 4 . Base layer  402  defines a weight pocket  426  and pocket housing  436  is molded as part thereof In this view living hinge  512  and tine  522  of connection feature  412  can be seen. Elastomeric interconnection reinforcement portion  514  is also shown. 
         [0023]    The described embodiments provide a high performance razor with an easy to use and low cost interconnection for replaceable blade cartridges. The handle is manufactured by injection molding, the base layer insertion of the weights within the one or more weight pockets defined within the base layer followed by the over molding of an elastomeric reinforcement layer. The simplicity of this manufacturing process yields a highly cost efficient product. 
         [0024]    In the foregoing specification, the embodiments of the invention have been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.