The present subject matter relates to shaving systems of a wet shave type, and in particular relates to razor cartridges and housings therefor.
Many modern safety razors include a disposable razor cartridge adapted to be selectively connected to a reusable handle by connecting structure therebetween. The cartridge includes a housing or frame having at least one razor blade with a sharpened cutting edge disposed therein. Other modern safety razors include a razor cartridge permanently connected to the handle that can be disposed of as a single unit.
The performance and commercial success of a razor cartridge is a balance of many factors and characteristics that include the accuracy and repeatability of positioning the razor blade(s) within the cartridge housing in order to provide optimal shaving geometry, such as exposure, angle and span.
In WO-A-2007/147420 a razor cartridge includes a plastic platform member and a plastic cover that are separate component parts. Blades are positioned in the platform and are located by features of the cover. The cover is assembled to the platform in a vertically downward direction (as seen in
In U.S. Pat. No. 4,184,247 a safety razor for a so-called double edge blade is disclosed. The razor includes a platform portion having guard portions. The platform portion is adapted to receive a razor blade, and a cap portion molded integrally with the platform portion. Means are provided to securely fasten the cap portion to the platform portion.
The present disclosure has for its objective to eliminate, or at least substantially alleviate the limitations of prior art razor cartridges. A method of making a razor cartridge is disclosed. A housing that includes an elongated body is provided. The elongated body has, integrally formed, a guard, a cap and an interior wall that extends between the guard and the cap at or close to an end of the elongated body. The interior wall includes a slot. An exterior wall extends from the interior wall in a direction along and outwardly of the elongated body and is joined to the interior wall by a film hinge. Preferably the interior wall includes a shelf and the exterior wall extends from the shelf. A razor blade is positioned in the housing by inserting a portion of a body of the razor blade in the slot. The exterior wall is folded about the film hinge so that a lip of the exterior wall overlays an end portion of a cutting edge of the razor blade to secure the razor blade within the housing. The exterior wall is then additionally secured to the elongated body (i.e. in addition to the film hinge) in a region spaced apart from the film hinge to provide a razor cartridge.
In some embodiments the exterior wall can include a protrusion that engages the body of the razor blade when the exterior wall is folded to locate the body within the slot and thus the razor blade within the housing. The exterior wall can be additionally secured to the elongated body portion by an application of a suitable adhesive or by welding methods. The exterior wall can also be additionally secured to the elongated body portion by a non-adhesive method such as by a snap-fit connection. The film hinge can comprise a thermoplastic elastomer material.
The housing can include a pair of interior walls at or close to opposed ends of the elongated housing body portion each having a respective outwardly extending exterior wall.
The body portion of the razor blade can include a first portion adjacent the cutting edge and a further portion bent at an angle relative to the first portion and a portion of the further portion is inserted in the slot of the interior wall.
The disclosed method offers manufacturing advantages by providing a one-piece housing that requires no additional component parts to secure the razor blade within the housing. The disclosed method offers advantages of improved positional accuracy of the razor blade and thus its cutting edge within the housing.
These and other advantages of the present disclosure will be apparent to one of ordinary skill in the art in light of the following Detailed Description and Drawings.
Reference is made to the attached drawings, wherein elements having the same reference numeral designations represent like elements throughout, and wherein:
Referring now to the drawings and in particular
The cartridge also comprises one or more than one razor blades 40. As depicted six (6) razor blades are provided but any number can be provided, e.g. one, two, three, or more or less than six. Referring additionally to
In the lateral end region of the elongated body 13 an interior wall 30 extends between the guard and cap in a position at or preferably close to an end of the elongated body. An interior wall 30 can be provided at each opposed end region of the housing body portion. The interior wall 30 includes one or more slots 32 to engage bodies of respective razor blade(s), e.g. part or substantially all of the further body portion 48 of the razor blade of
In some embodiments the interior wall 30 is also provided with a support surface 34 provided to engage the underside of e.g. the first planar body portion 44 of the razor blade 40.
An exterior wall 60 extends from the interior wall 30 in a direction along and outwardly from the elongated body 13 as depicted in
The exterior wall 60 also includes lip 64. The exterior wall can also include protrusion 66 that is provided with a location surface 68 to engage the upperside of e.g. the first planar body portion 44 of the razor blade 40. The protrusion 66 can further be provided with a second location surface 70 to locate the cutting edge 42 of the next adjacent razor blade 40 (see
During the assembly process of the razor cartridge, the housing 12 is provided in the form depicted in
Preferably the housing is manufactured by an injection molding process. A so-called multi-shot, e.g. a two- or three-shot molding process is more preferable as a skin stretching/skin stimulating elastomeric member 18 and/or a shaving aid member 20 can be integrally formed thereby as is known in the art. The housing is preferably injection molded ABS, more preferably the material designated GP-35, manufactured by BASF. This specific ABS is selected for properties that include: good compatibility with CA adhesive (where used); good dimensional stability at molding, good chemical resistance to substances typically found in a normal shaving environment and good impact strength. One of skill in the art will understand other thermoplastic molding materials such as polyphenylene oxide (PPO) or blends of ABS and other materials such as polyamide or polycarbonate can also be selected. Although component parts using film hinges are typically formed from olefinic materials such as polypropylene (PP) in the present disclosure the film hinge undergoes only a one-time movement from the as-provided position (e.g. in
In
While the foregoing has described what are considered to be the best mode and/or other examples, it is understood that various modifications can be made therein and that the subject matter disclosed herein can be implemented in various forms and examples, and that the teachings can be applied in numerous applications, only some of which have been described herein. For instance, features disclosed in connection with any one embodiment can be used alone or in combination with each feature of the respective other embodiments. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings.
This application claims the benefit of U.S. Provisional patent application Ser. No. 61/597,971, filed Feb. 13, 2012, the content of which is incorporated herein in its entirety for reference.
Number | Date | Country | |
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61597971 | Feb 2012 | US |