The present invention relates to shaving razors and more particularly to shaving razor cartridges having a housing and an elongated skin contacting member secured to the housing.
In general, shaving razors of the wet shave type include a cartridge or blade unit with 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 it 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 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.
In the use of shaving razors of the wet shave type, factors such as frictional drag of the razor across the skin, force needed to sever hairs, and irritation or pre-existing skin damage can create a degree of shaving discomfort. Shaving aids, e.g., a lubricant, whisker softener, razor cleanser, medicinal agent, cosmetic agent or combination thereof, have been incorporated into razors, for example by incorporating a shaving aid into one or more extruded or molded polymeric components of the razor. Such shaving aid composites may be mounted on the cap or guard structures of the razor cartridge. Upon exposure to water, water-soluble shaving aid leaches from the composite onto the skin and the composite tends to swell.
The shaving aid composites must be positively secured for effective dispensing throughout the useful shaving life of the razor. Forces during shaving may contribute to loosening of the shaving aid components from the cartridge. Numerous extruded or molded shaving aid components have been developed which are secured to the shaving razor cartridge with adhesives. These arrangements have been unsatisfactory for certain applications. Adhesives are typically a poor choice for several reasons. Adhesives are difficult to work with from a manufacturing perspective and are also susceptible to changes in heat and humidity. In certain countries, shaving razors are exposed to constant high levels of heat and humidity during shipment and storage. These levels of heat and humidity can adversely affect the adhesive properties such that the lubrication component is no longer secured. Various press-fit type designs have also been developed to secure the shaving aid component to the cartridge of the shaving razor. The various press-fit type designs have also proven to be ineffective in certain applications. Press-fit designs rely on a significant amount of force to be applied to the shaving aid composite in order to properly secure the shaving aid composite within the housing, which may cause the shaving aid composite to break or fracture. These designs are also not very effective because they do not accommodate for changing forces resulting from the shaving aid composite swelling and expanding. These cartridge designs also rely on an increased surface contact area with the shaving aid composite to better secure the shaving aid composite to the cartridge, which limits the cartridge design, such as the size of the cartridge and the placement of the blade(s).
In one aspect, the invention features, in general, a housing including a front wall and a rear wall which together define a pocket having a seat surface, wherein at least one of the front and rear walls include one or more flexible segments. One or more blades positioned below the seat surface. An elongated skin contacting member is provided that comprises a shaving aid composite that has one or more water-leachable shaving aid materials. The elongated skin contacting member has a body portion with an upper skin contacting surface and a base portion disposed at least partially within the pocket. The base portion has a bottom surface that is spaced apart from the seat surface, wherein the base portion extends laterally outwardly from the body portion and is in mechanical engagement with the one or more flexible segments to secure the elongated skin contacting member to the housing.
In another aspect, the invention features, in general, a shaving cartridge including a housing having a pocket defined by a front wall and a rear wall. One or more blades are mounted within the housing. An elongated skin contacting member is provided that has a width that is greater than its height. The elongated skin contacting member has a body portion with an upper skin contacting surface and a base portion disposed at least partially within the pocket. The base portion extends laterally outward from the body portion and is in mechanical engagement with at least one of the front and rear walls to secure the skin contacting member to the housing.
If, desired, particular embodiments may optionally include the elongated skin contacting member having a shaving aid composite with one or more water-leachable shaving aid materials. Particular embodiments may also optionally include the pocket having a seat surface that is spaced apart from the base portion to allow for swelling of the elongated skin contacting member. Particular embodiments may also optionally include a seat surface with a protrusion to provide support the elongated skin contacting member.
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter that is regarded as the present invention, it is believed that the invention will be more fully understood from the following description taken in conjunction with the accompanying drawings.
Referring to
In certain embodiments, the housing 18 may be molded from Noryl™ (a blend of polyphenylene oxide (PPO) and polystyrene developed by General Electric Plastics, now SABIC Innovative Plastics). The housing 18 may be molded from other semi-rigid polymers having a Shore A hardness of about 50, 60 or 70 to about 90, 110, or 120. The elongated skin contacting member 22 may be a separate molded or extruded component that is mounted to the housing 18. The elongated skin contacting member 22 may be molded or extruded from the same material as the housing 18 or may be molded or extruded from a more lubricious shaving aid composite that has one or more water-leachable shaving aid materials to provide increased comfort during shaving. The shaving aid composite may comprise a sheath of water-insoluble polymer that surrounds a core which includes a skin-lubricating water-soluble polymer.
Suitable water-insoluble polymers which may be used for the matrix (or sheath) include polyethylene, polypropylene, polystyrene, butadiene-styrene copolymer (e.g., medium and high impact polystyrene), polyacetal, acrylonitrile-butadiene-styrene copolymer, ethylene vinyl acetate copolymer and blends such as polypropylene/polystyrene blend, may have a high impact polystyrene (i.e., Polystyrene-butadiene), such as Nova HIPS 731G from Nova Chemicals.
Suitable skin lubricating water-soluble polymers may include polyethylene oxide, polyvinyl pyrrolidone, polyacrylamide, hydroxypropyl cellulose, polyvinyl imidazoline, and polyhydroxyethylmethacrylate. Other water-soluble polymers may include the polyethylene oxides generally known as POLYOX (available from Dow Chemical) or ALKOX (available from Meisei Chemical Works, Kyota, Japan). These polyethylene oxides may have molecular weights of about 100,000 to 6 million, for example, about 300,000 to 5 million. The polyethylene oxide may comprises a blend of about 40 to 80% of polyethylene oxide having an average molecular weight of about 5 million (e.g., POLYOX COAGULANT) and about 60 to 20% of polyethylene oxide having an average molecular weight of about 300,000 (e.g., POLYOX WSR-N-750). The polyethylene oxide blend may also contain up to about 10% by weight of a low molecular weight (i.e., MW<10,000) polyethylene glycol such as PEG-100.
The shaving aid composite 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.
The design of the cartridge 14 and the elongated skin contacting member 22 may facilitate easy removal and replacement of the elongated skin contacting member 22. Frequently, the blades 20 and the elongated skin contacting member 22 do not wear at the same rate. If the elongated skin contacting member 22 wears faster than the blades 20, the entire shaving razor 10 or cartridge 14 must be replaced prematurely. In certain embodiments, if the user is no longer satisfied with the performance of the shaving cartridge 14, due to perceived lack of lubricity, the elongated skin contacting member 22 may be easily removed and replaced. The replacement of the elongated skin contacting member 22 may be even more advantageous for double edge style shaving razors, which incorporate a replaceable razor blade, rather than replacing the entire cartridge and/or shaving razor.
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The housing 18 may have a pocket 40 that is dimensioned to receive the elongated skin contacting member 22. The pocket 40 may be defined by a front wall 42 and a rear wall 44. The pocket 40 may also be defined by a pair of side walls 46 and 48. The side walls 46 and 48 may be spaced apart from the elongated skin contacting member 22 to improve the ease of assembly and allow for swelling and expansion of the elongated skin contacting member 22. The rear wall 44 may include one or more flexible segments 50, 52, 54, 56 and 58, each having a free end 51, 53, 55, 57, and 59. The flexible segments 50, 52, 54, 56 and 58 may include deflectable members, such as latches to facilitate securing the elongated skin contacting member 22 to the housing 18. The flexible segments 50, 52, 54, 56 and 58 may also deflect to accommodate swelling of the elongated skin contacting member 22 due to absorption of water. The rear wall 44 may include one or more retention segments 60, 62, 64, and 66 that are positioned between the flexible segments 50, 52, 54, 56 and 58. The retention segments 60, 62, 64, and 66 may be generally rigid to support the elongated skin contacting member 22 within the pocket 40 and prevent excess deflection of the flexible segments 50, 52, 54, 56 and 58, which may result in the elongated skin contacting member 22 disengaging from the housing 18. The flexible segments 50, 52, 54, 56, and 58 and the retention segments 60, 62, 64, and 66 may be spaced apart to allow for expansion of the elongated skin contacting member 22 in-between adjacent segments 50, 52, 54, 56, 58, 60, 62, 64, and 66. The spacing may minimize the force applied to the front and rear walls 42 and 44 as the elongated skin contacting member 22 swells and expands beyond its original shape. The front wall 42 may also have a plurality of spaced apart segments 70, 72, and 74. The plurality of spaced apart segments 70, 72, and 74 may include deflectable members or generally rigid retention members. The front and rear walls 42 and 44 may include any possible combination of retention segments 60, 62, 64, and 66 and flexible segments 50, 52, 54, 56, and 58 to secure the elongated skin contacting member 22 within the housing 18. The front and/or rear walls 42 and 44 may even include flexible segments 50, 52, 54, 56, and 58, but no retention segments 60, 62, 64, and 66. In certain embodiments, the housing 18 may include the front wall 42 that is generally solid and the rear wall 44 with a plurality of flexible segments 50, 52, 54, 56, and 58. Alternatively, the housing 18 may include the rear wall 44 that is generally solid and the front wall 42 with a plurality of flexible segments 50, 52, 54, 56, and 58.
The repetitive swelling and shrinking of the shaving aid component is an issue for typical cartridges because the shaving aid component has a tendency to loosen from the cartridge and eventually fall out. Unlike press-fit or press-in designs, the front and rear walls 42 and 44 of the housing 18 may allow for repetitive swelling and shrinking of the elongated skin contacting member 22 without the elongated skin contacting member 22 disengaging from the housing 18. Also, once assembled, the front and rear walls 42 and 44 of the housing 18 require very little force to maintain the elongated skin contacting member 22 secured. Due to the reduced forces applied to the elongated skin contacting member 22, the wall thickness and cross sectional profile of the elongated skin contacting member 22 may be reduced without risking damage to the elongated skin contacting element 22 during assembly or shaving. The reduced forces may also allow the skin contacting member 22 to have an increased number of possible formulations that could not have been used before because of concerns regarding the strength of the shaving aid composite used to manufacture the skin contacting member 22. For example, improved shaving aid composites with enhanced skin benefits may used for the skin contacting member 22 even if the improved shaving aid composite used is weaker than standard shaving aid composites.
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The base portion 34 may have a width “w1” that is greater than a distance “d1” between the front wall 42 and the rear wall 44. For example, w1 may be greater than d1 by about 3%, 5%, or 7% to about 10%, 15%, or 20%. In certain embodiments, d1 may be about 1 mm, 2 mm, or 3 mm to about 3.5 mm, 4 mm or 4.5 mm. The base portion 34 may be dimensioned to fit securely between the front wall 42 and the rear wall 44 of the housing 18. In certain embodiments, w1 may be about 1.5 mm, 2.5 mm, or 3.5 mm to about 4.5 mm, 5 mm or 5.5 mm. The body portion 30 may have a width “w2” that is less than “w1”. In certain embodiments, w2 may be about 1 mm, 2 mm, or 3 mm to about 4 mm, 4.5 mm or 5 mm. As the base portion 34 is inserted into the pocket 40, one or more of the flexible segments 54 of the rear wall 44 may deflect to accommodate the larger width of the base portion 34. Once the base portion 34 is properly secured within the pocket 40, one or more of the flexible segments 54 may deflect back to its original position resulting in an audible feedback, such as a snap or a click sound. The audible feedback is useful during assembly to signal the person operating or managing the assembly process that the elongated skin contacting member 22 is properly secured to the housing 18. The base portion 34 may be in mechanical engagement with one or more of the flexible segments 54 of the rear wall 54 and one or more of the segments 72 of the front wall 42, such that one or more of the flexible segments 54 and one or more of the segments 72 overlap at least a portion of the base portion 34 (i.e., lateral end portions 92 and 94), thus preventing disengagement or expulsion of the elongated skin contacting member 22 from the housing 18. In certain embodiments, the body portion 30 may not be in mechanical engagement or contacting the rear wall 54 or the front wall 42. The base portion 30 not contacting the rear wall 54 or the front wall 42 may allow for improved contact with the skin for an enhanced tactile feel.
The elongated skin contacting member 22 may have a relatively small wall thickness to reduce costs, or may be comprised of a weaker material in order to achieve certain shaving benefits, such as increased skin lubrication. The mounting or attachment of the elongated skin contacting member 22 to the housing 18 requires less force than other mechanical assembly methods. For example, press-fit designs may break or damage the elongated skin contacting member 22 during attachment because of the increased force needed for proper assembly and the reduced strength of the elongated skin contacting member 22.
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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”. In an effort to avoid any ambiguity, for the purposes of this disclosure, the term “portion” shall be construed as meaning less than 50%. For example, the term “distal end portion” should be interpreted as from about 0%, 5%, 10%, or 15% to about 15%, 20%, 25%, 30%, 40% or 45% from the terminal end of the element referenced. Similarly, the term “proximal end portion” should be interpreted as from about 0%, 5%, 10%, or 15% to about 15%, 20%, 25%, 30%, 40% or 45% from the end opposite the terminal end of the element referenced.
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.