Patent Application
20110203124
The present invention relates to wet shaving blade assemblies, and more particularly, to wet shaving blade assemblies in which at least one blade is protected by a removable protective cover.
In general, a cartridge or blade unit of a safety razor has at least one blade with a cutting edge which is moved across the surface of the skin being shaved by means of a handle to which the cartridge is attached. The cartridge may be mounted detachably on the handle to enable the cartridge to be replaced by a fresh cartridge when the blade sharpness has diminished to an unsatisfactory level, or the cartridge may be attached permanently to the handle with the intention that the entire razor be discarded when the blade or blades have become dulled. Razor cartridges usually include a guard which contacts the skin in front of the blade(s) and a cap for contacting the skin behind the blade(s) during shaving. The cap and guard may aid in establishing the so-called “shaving geometry”, i.e., the parameters which determine the blade orientation and position relative to the skin during shaving, which in turn have a strong influence on the shaving performance and efficacy of the razor. The guard may be generally rigid, for example formed integrally with a frame or platform structure which provides a support for the blades.
Various types of protective covers, which are also known as overcaps, have been utilized with commercially available razors and razor cartridges. These covers may serve several purposes. First, the cover protects the razor cartridge and the blade edges during the different stages of shipping and retailing from forces which may damage the blade edges. Secondly, the cover also protects a user from unintentionally encountering the razor's sharp blade edge when the razor is not in use. Furthermore, the cover may serve as a storage unit for the razor cartridge between shaves. The covers which are currently available typically require a removal force in the direction of separation (i.e., the cover is either pulled or pushed directly off of the razor in the direction of the applied force). The removal of the cover may present issues for shaving razors that have a detachable cartridge because the user often unintentionally pulls the cartridge off of the handle because both the cartridge and the cover require the removal force in the same direction. The attachment mechanism of the shaving razor cartridge of handle may be damaged by the unintentional removal of the razor cartridge from the handle. In addition, the covers that are currently available require complex geometries to secure the overcap to the shaving razor cartridge. These complex geometries require the cover to be injection molded, which can increase capital costs, component costs, and manufacturing efficiency.
Many commercially available razor cartridges have a lubricating strip positioned on the cap, which is located behind the blades. The lubricating strip absorbs water and leaches out one or more lubrication aids during shaving to reduce the frictional drag of the blades against the skin. After shaving the user may store the cartridge in the cover. The lubricating strip may contact the cover, which may prevent proper drying of the lubricating strip or potentially damage the lubricating strip during subsequent removal. Furthermore, if the lubricating strip is not allowed to properly dry, it may continue to leach out water and shaving aid during storage. The water and shaving aid may leach onto the blades or the guard of the cartridge. The consumer may intuitively wipe the blade clean with a towel, but this may damage the edges of the blades. If water and shaving aid are allowed to dry on the blades, the blade edges may corrode faster and/or require extensive rinsing to remove the dried shaving aid prior to the next shave.
In one aspect, the invention features, in general, a shaving cartridge-cover assembly having a housing with a guard, a cap, a rear wall with at least one retention member, a front wall, and a pair of side walls. At least one blade is mounted to the housing between the guard and the cap. A protective cover has a top wall, a front wall and a rear wall that define a pair of opposing open ends. The housing has a dimension between the retention member and the front wall that is greater than an inner width of the open ends of the protective cover such that sliding one of the side walls of the housing into at least one of the open ends deflects the front and rear walls of the protective cover to facilitate mounting of the protective over the housing.
In another aspect, the invention features, in general, a shaving cartridge-cover assembly with a housing having a rear wall, an opposing front wall, a guard, a cap, and a pair of spaced apart retention members on the rear wall of the housing. At least one blade is mounted to the housing between the guard and the cap. A protective cover is removably mounted to the housing. The protective cover has a uniform cross sectional profile defining a pair of opposing open ends each having an inner width. The protective cover has a first position and a second position. In the first position, the inner width of at least one of the open ends is less than a distance between at least one of the retention members and the front wall of the housing. In the second position, the inner width of at least one of the open ends is greater than a distance between at least one of the retention members and the front wall of the housing.
In yet another aspect, the invention features, in general, a shaving cartridge-cover assembly having a protective cover with a uniform cross sectional profile with a front wall, a rear wall, and a top wall interconnecting the front and rear walls. A housing is removably mounted to the protective cover. The housing has a rear wall, a front wall, a guard, a cap, and at least one blade between the guard and the cap. At least one of the front and rear walls of the housing has a pair of spaced apart retention members and the protective cover is mounted between the pair of retention members and covers at least a portion of the blade.
Referring to
The protective cover 40 may be formed from a polymeric material using an extrusion process. Polymeric materials may include, but are not limited to polyolefins, such as polypropylene, polyethylene, and combinations thereof. The extrusion process is a method of producing near net shaped components of a uniform or constant cross-sectional profile to close tolerances in one operation. During the extrusion process, a solid polymeric material (also called a resin), usually in the form of beads or pellets, is continuously fed to a heated chamber and carried along by a feedscrew within. As the plastic material is conveyed it is compressed, melted, and forced out of the chamber at a steady rate through a die. The immediate cooling of the melt results in resolidification of the polymeric material into a continually drawn piece having a cross section matches the die profile. The extrusion process may be continuous (theoretically producing indefinitely long material) or semi-continuous (producing many pieces). Long pieces of extruded material may be cut to length at a later stage in the manufacturing process. Dies are engineered and machined to ensure that the melt flows in a precise desired shape, as well as, compensate for effects of shrinkage when a melt re-solidifies. A wide variety of materials may be extruded, including polymeric materials, metals, ceramics, concrete and paperboard.
One advantage of extrusion process over other manufacturing processes is the ability to create very complex cross-sections. Another advantage of extrusion is the ability to process materials that are brittle, because the material only encounters compressive and shear stresses during processing. Extrusion also forms finished parts with an excellent surface finish. Furthermore, there are financial benefits to be gained from using an extrusion compared to other methods of manufacture (e.g., injection molding). Complex extruded shapes that are close to the finished product profile can be produced in one operation, which enables very significant savings to be made on raw material usage and secondary operations. The material yield loss due to secondary machining or finishing operations can be greatly reduced or totally eliminated by using a near net extruded section. Higher value materials may also utilized because of the greater savings that result from the extrusion process. In addition, the tooling costs for an extrusion die (compared to injection molds) are low and the production change over down time between different sections is also comparatively short. Therefore, either long or short production runs are both practical and economical using the extrusion process.
The handle 12 and/or the shaving cartridge 20 may be injection molded from a semi-rigid polymeric material, for example, Noryl™ (a blend of polyphenylene oxide (PPO) and polystyrene developed by General Electric Plastics, now SABIC Innovative Plastics). The handle 12 and/or the shaving cartridge 20 may be molded from other semi-rigid polymeric materials having a Shore A hardness of about 50, 60, or 70 to about 90, 110, or 120, such as high impact polystyrene, polypropylene, acrylonitrile butadiene styrene, or any combination thereof. A semi-rigid polymeric material may allow the handle 12 and/or the shaving cartridge 20 to maintain a consistent geometry during shaving. The handle 12 and/or the shaving cartridge 20 may be of sufficient stiffness such that it does not bend or flex under normal shaving conditions, which may adversely influence the shave geometry of the shaving cartridge-cover assembly 10. In certain embodiments, the handle 12 and/or the shaving cartridge 20 may be manufactured from metals including, but not limited to aluminum or stainless steel.
Referring to
The cap 26 may also optionally include an inclusion complex of a skin-soothing agent with a cylcodextrin, low molecular weight water-soluble release enhancing agents such as polyethylene glycol (e.g., 1-10% by weight), water-swellable release enhancing agents such as cross-linked polyacrylics (e.g., 2-7% by weight), colorants, antioxidants, preservatives, microbicidal agents, beard softeners, astringents, depilatories, medicinal agents, conditioning agents, moisturizers, cooling agents, etc.
At least one blade 32 may be mounted to the housing 22 between the guard 24 and the cap 26. The blade 32 may have an exposed cutting edge 34 for cutting hair as the shaving cartridge 20 is moved across the surface of the skin. The blade 32 may be secured to the housing 22 using a cold staking process, but other assembly/securing methods known to those skilled in the art may be used including, but not limited to, wire wrapping, clips, hot staking, insert molding, and adhesives. Although only one blade 32 is shown, it is understood that the housing 22 may have more blades (e.g., two, three, four, five, or more). The guard 24 and the cap 26 may facilitate the protection of skin in a direction transverse to the blade 32 (e.g., minimizing nicks and cuts during shaving or handling of the shaving cartridge 20). However the guard 24 and the cap 26 may not protect against slicing (i.e., cutting in a direction parallel to the blade 32). As will be explained in greater detail below, the protective cover 40 may be mounted to the shaving cartridge 20 such that the blade 32 is not exposed (i.e., the protective cover 40 covers at least a portion of the blade 32).
The housing 22 may have a pair of opposing side walls 27 and 29 each having a width w1 between the front wall 28 and the rear wall 30 of about 10 mm, 12 mm, or 14 mm to about 16 mm, 18 mm, or 20 mm. In certain embodiments, the rear wall 30 of the housing 22 may have a pair of spaced apart retention members 36 and 38 that minimize the unintentional removal of the protective cover 40 from the cartridge 20. The retention members 36 and 38 may include a raised surface such as a bump. The retention members 36 and 38 may also include a surface directly adjacent a recessed area. The retention members 36 and 38 may have a height h1 measured outward from the rear wall 30 of about 0.15 mm, 0.25 mm, or 0.3 mm to about 0.35 mm, 0.4 mm, or 0.45 mm. The height h1 may be increased or decreased to increase the force required to slide off the protective cover 40. At least one of the retention members 36 and 38 may have a straight inner wall 39 and 41 that is perpendicular to the rear wall 30 and the blade 32 (e.g., about 80 degrees, 84 degrees, or 88 degrees to about 90 degrees, 95 degrees, or 100 degrees). The straightness and/or angle of the inner walls 39 and 41 in relation to the rear wall 30 may increase the force required to remove the protective cover 40 without increasing the force required slide the protective cover 40 over the cartridge 20. A distance d1 between at least one of the retention members 36 and 38 and the front wall 28 of the housing 22 may be greater than the width w1 of the housing 22. For example, the distance d1 may be about 12 mm, 14 mm, or 16 mm to about 24.5 mm, 26.5 mm, or 28.5 mm. It is understood that the dimensions for d1 and w1 may vary depending on the size of the cartridge 20 and/or housing 22. The protective cover 40 may expand to slide over the retention members 36 and 38 and then relax as the protective cover 40 is positioned between the pair of retention members 36 and 38. An audible sound, such as a click or a snap, may result as the protective cover 40 relaxes against the housing 22 to signal to the user that the protective cover 40 is properly mounted to the housing 22. The retention members 36 and 38 may allow the protective cover 40 to expand and slide over the cartridge 20, but prevent unintentional removal (e.g., sliding off) of the protective cover 40 from the cartridge 20.
Referring to
The protective cover 40 may have a first position and a second position to facilitate the mounting and/or removal of the protective cover 40 from the cartridge 20. In the first position, at least one of the open ends 60 and 70 of the protective cover 40 may have an inner width w2 from the rear wall 44 to the front wall 42 (e.g., convex inner surface portion 43). The inner width w2 of at least one of the open ends 60 and 70 of the protective cover 40 in the first position may be less than d1 (see
The dimension d1 of the housing 22 (see
Referring to
As shown in
In certain embodiments, the top wall 46 of the protective cover 40 may spaced apart (i.e., open space 57) from the cap 26 by about 0.5 mm, 0.75 mm, or 0.8 mm to about 1.0 mm, 1.5 mm, or 2.5 mm. The open space 57 and the open ends 60 and 70 (see
Referring to
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
