CARTRIDGE

CROSS REFERENCE TO RELATED APPLICATIONS

The present disclosure claims priority of U.S. provisional patent application No. 61/334,377 filed May 13, 2010, the contents of which are incorporated herein in their entirety.

TECHNICAL FIELD

The present subject matter relates to shaving razor systems. The present subject matter has particular applicability to shaving systems of the wet shave type.

BACKGROUND

Certain current conventional wet shaving systems feature razor cartridges that carry a plurality of razor blades, each blade being welded to a bent blade support. The blade/support assemblies each fit into respective slots at either end of a central opening of a cartridge housing. Some conventional cartridge bodies include springs, such as leaf- type spring fingers, which bias the blade/support assemblies upward. A pair of metal clips is typically provided extending across the blades at respective opposing ends near the slots. The clips engage the underside of the cartridge housing to retain the blade/support assemblies in the cartridge housing.

A clip, or blade retainer functions to allow blades to be assembled to a housing or other cartridge components, thereby building a razor cartridge that does not require other methods of assembly, such as deforming plastic to stake blades and plastic together. Retainers can establish a reference plane for blade edges that are assembled into a cartridge structure. The blade edges are typically held against the rear face of the retainer by plastic springs. This builds into the assembly a consistent cartridge geometry based on blade edge position, with the retainer/cartridge designed to cooperate to yield the most desired geometry.

Retainers can be constructed using anodic materials based on galvanic activity such as aluminum, magnesium, beryllium, zinc, etc. or combinations thereof, to protect the blades from corrosion. This requires that the blade electrically contact the metal retainer.

Conventional retainers have certain disadvantages, such as including the challenge of making secure assemblies, and maintaining this over extended manufacturing runs. Razor cartridges must maintain assembly integrity if the razor cartridge is accidentally dropped or otherwise subjected to normal or abnormal stresses during use. Various methods have been used to contain the retainer in the cartridge housing using an interlocking feature.

Retainer processing can also result in undesirable sharp features that can be apparent to the user during shaving. In addition, distortion of the retainer shape, either while forming the retainer or assembling the retainer to the cartridge housing, could result in poor electrical conductivity to the blades. This can cause loss of anodic/cathodic blade corrosion protection. SUMMARY

According to the present disclosure, advantages are achieved over conventional razor cartridges in part by a retainer for retaining a blade in a shaving cartridge housing. The retainer comprises a central portion for extending across a minor axis of the blade, and a pair of legs extending from respective distal ends of the central portion to form substantially a U-shape with the central portion. Each leg is for insertion into a respective opening in the cartridge housing, and has a protrusion to engage a first wall of its respective cartridge housing opening, to restrict movement of the retainer relative to the cartridge housing.

In accord with another aspect of the disclosure, each leg of the retainer is inserted into a respective opening in the cartridge housing along an insertion axis. The legs are deformable after insertion to a position offset from the insertion axis to engage a wall of its respective cartridge housing opening, to restrict movement of the retainer relative to the cartridge housing.

Alternatively, each leg comprises an elastically compressible distal end portion wider than the opening when uncompressed, the distal end portion being compressible to fit into the opening during insertion, and expandable after insertion to restrict movement of the retainer relative to the cartridge housing.

In accord with yet another aspect of the disclosure, a method of assembling a razor cartridge is described, the method comprising providing a retainer for retaining a blade in a cartridge housing, the retainer comprising a central portion for extending across a minor axis of the blade, and a pair of legs extending from respective distal ends of the central portion to form substantially a U-shape with the central portion. Each leg is for insertion into a respective opening in the cartridge housing along an insertion axis. The method also comprises deforming each leg after insertion to a position offset from the insertion axis to engage a wall of its respective cartridge housing opening, to restrict movement of the retainer relative to the cartridge housing.

In accord with yet another aspect of the disclosure, a razor cartridge is described, comprising a blade, a cartridge housing, and a retainer for retaining the blade in the cartridge housing. The retainer comprising a central portion for extending across a minor axis of the blade, and a pair of legs extending from respective distal ends of the central portion to form substantially a U-shape with the central portion. The cartridge housing has a pair of openings for respectively receiving the pair of retainer legs, each opening having a first portion extending along an insertion axis of the leg and a second portion in communication with the first portion and extending in a direction offset from the insertion axis. The retainer legs are sequentially inserted into the first portion and the second portion of the respective openings, and are deformed by the second portion to engage a wall of the second opening, to restrict movement of the retainer relative to the cartridge housing.

Additional advantages and novel features will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following and the accompanying drawings or can be learned from production or operation of the examples. The advantages of the present teachings can be realized and attained by practice or use of the methodologies, instrumentalities and combinations particularly pointed out in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

Reference is made to the attached drawings, wherein elements having the same reference numeral designations represent like elements throughout.

Figs, la- lb illustrate details of a cartridge using razor blade retainers according to the present disclosure.

Figs. 2 a-2f illustrate a retainer according to the present disclosure.

Figs. 3a-3b illustrate a retainer according to one embodiment of the present disclosure.

Figs. 4a-4c illustrate a retainer according to other embodiments of the present disclosure.

Fig. 5 illustrates a retainer according to one embodiment of the present disclosure.

Figs. 6a-6c illustrate a retainer according to other embodiments of the present disclosure.

Fig. 7 illustrates a retainer according to one embodiment of the present disclosure.

Fig. 8 illustrates a retainer according to one embodiment of the present disclosure.

Fig. 9 illustrates a retainer according to one embodiment of the present disclosure.

Figs. 10a- lOg illustrate a retainer according to one embodiment of the present disclosure. Figs. 11 a- 11 g illustrate a retainer according to one embodiment of the present disclosure.

Fig. 12 illustrates a retainer according to one embodiment of the present disclosure.

Fig. 13 illustrates a retainer according to one embodiment of the present disclosure.

DETAILED DESCRIPTION

A shaving cartridge using the blade retainers of this disclosure will now be generally described with reference to Figs, la- lb. The cartridge shown in Figs, la- lb is intended as merely exemplary, and not exclusive or limiting in any way. The cartridge includes a housing 20 having a central opening 25 into which a plurality of blade assemblies, each comprising a blade 40 welded or otherwise joined to a bent blade support, are inserted. In other embodiments the blade can include a bent portion such that the blade is e.g. substantially L-shaped and the support can be eliminated.

As shown in Figs. 2a-2e, the blade assemblies are retained in the cartridge housing 20 by a pair of blade retainers 50 at respective ends of the central opening 25 of the housing. The retainers 50 are substantially U-shaped, with a central portion 60 that extends across the blades, and a pair of legs 70 that extend into openings 30 in the top of the housing 20. The openings 30 can extend into the housing and can extend to the bottom of the housing. Figs. 2a-2f are various representations of a retainer 50 of certain embodiments of the present disclosure. As is shown in Figs. 2a-2e, the legs 70 of the U-shaped retainer 50 can have a series of protrusions 72 which will be described later. As shown, for example, in Figs. 2b-2d, the central portion 60 has a domed portion 60a that extends from the central portion 60 away from the legs 70.

The domed portion 60a features a reduced surface area for reducing drag during shaving by reducing the contact area with the skin. The domed portion 60a, which extends away from the legs 70, is designed to lift the skin away from any sharp corners of the retainer 50, thereby improving the perception of comfort during shaving. Forming the domed portion 60a also increases the beam strength of the central portion 60 of the retainer 50, providing greater geometric stability under pressure and improving the straightness of the retainer 50 at the point of blade contact. This allows for consistent shave geometry and optimal performance.

The coining of the domed portion 60a in the retainer 50 reduces the available area for contact between the blade edge and the retainer 50. As a result, the pressure at the point of contact of the blade with the retainer is increased, and the electrical connectivity is improved. In another embodiment, such as a view of the underside of the retainer as shown in Fig. 2e, the domed portion 60a can extend towards the legs 70. This feature also can increase electrical connectivity between the retainer 50 and the blades. Further, by extending the domed portion 60a towards the legs 70, the retainer 50 more rigidly holds the blades in the housing 20.

As shown in Fig. 2a, the disclosed retainers 50 are coined (i.e., embossed) with one or more interlock features to lock the retainer 50 to the cartridge housing 20. In the embodiment shown in Figs. 2a-2e, the legs 70 of the retainer 50 have an upper leg portion 70a and a lower leg portion 70b. The legs 70 are bent over themselves to create a double wall with protrusions 72 on each leg 70, to increase the locking action of the retainer in the opening 30. Each upper leg portion 70a has a protrusion 72 to engage a first wall 32 (such as shown in Fig. 3b) of a respective cartridge housing opening 30, to restrict movement of the retainer 50 relative to the cartridge housing 30. The wider legs 70 also allow use of a larger opening 30 in the housing, thereby providing manufacturing (e.g. molding) advantages.

Fig. 2f is a cross-section of the top surface of the central portion 60 having a domed portion 60a. The central portion 60 further comprises a flat portion 60b surrounding the domed portion 60a.

In another embodiment shown in Figs. 3a-3b, the leg 70 has an upper leg portion 70a which extends in a first direction along an insertion axis X. The lower leg portion 70b extends at an angle to the upper leg portion 70a in a second direction different the first direction (see Fig. 3b), such that a distal end of the lower leg portion 70b engages a second wall 34 of its respective cartridge housing opening 30 when the protrusion 72 engages the first wall 32.

In the embodiment shown in Figs. 3a-3b, the opening 30 has a first portion 30a extending along an insertion axis X of the leg 70 and a second portion 30b in communication with the first portion 30a and extending in a direction offset from the insertion axis X. The retainer leg 70 is sequentially inserted into the first portion 30a and the second portion 30b of the opening 30, and is deformed by the second portion 30b to engage walls 32, 34 of the second portion 30b, to restrict movement of the retainer relative to the cartridge housing.

As can be seen in Figs. 3a-3b, the second portion 30b of the opening 30 has an indentation 32a for mating with the protrusion 72 after the leg 70 is deformed. The protrusion 72 can have any shape suitable for mating with a corresponding depression 32a. For example, in the embodiment shown in Fig. 4a, the protrusion 72 is oval-shaped. In this embodiment, the protrusion 72 comprises raised ridges 72a for engaging the first wall 32.

In other embodiments, the protrusion 72 comprises sharp extended portions 73 for embedding in the first wall 32 such as shown in Fig. 4b. The sharp portions 73 provide greater friction when being pressed against the first wall 32. i this embodiment, the leg 70 also comprises a through-hole 74, and the sharp extended portion 73 comprises a burr attached to an edge of the through-hole 74. In yet other embodiments, other protrusions 72 extend from a side edge of the leg 70, such as shown in Fig. 4b. The use of the leg 70 having a protrusion 72 can be sufficient to hold the retainer 50 in the housing without bending, such as shown in Fig. 4c. Fig. 5 shows another embodiment of the present disclosure in which each leg 70 is deformable after insertion to a position offset from the insertion axis X to engage a wall 32 of its respective cartridge housing opening 30, to restrict movement of the retainer relative to the cartridge housing. One method to assemble a razor cartridge having this feature is performed by holding the cartridge housing rigidly and extending a fixed angular member 90 through the bottom of the housing and contacting the leg 70 after the leg 70 is inserted into the opening 30 to achieve horizontal bending of the leg 70. In another embodiment, a machine component 100 having a fixed angular member 90 is extended through the bottom of the housing and retracted to accomplish the bending necessary for each assembly.

Figs. 6a-6c show another embodiment of the present disclosure, in which the opening 130 extends downward at one width, and then expands to a larger width deeper in the direction of insertion along the insertion axis X. In Figs. 6a and 6b, each leg 70 comprises a distal end portion having two branches 80a, 80b. Each of the branches 80a, 80b are deformable, such as by a tool, after insertion to a position offset from the insertion axis X. As shown in Fig. 6b, the branches 80a, 80b are deformed, such as by twisting, to form the interference fit with the walls 132 and 134 in the wider portion of the opening 130. In another embodiment, the branches 80a, 80b of Fig. 6b form a shape which is effectively a spring, such that the leg 70 collapses when inserted and then expands upon reaching the wider portion of the opening 130. As a result, the spring action of the branches 80a, 80b retain the blades (not shown) under a designed preload. In another embodiment shown in Fig. 6c, the leg 70 of the retainer 50 is twisted about its axis such that the sides of the leg 70 form an interference fit with the sides of the walls 132, 134 of Fig. 6b.

Using a similar housing configuration as Fig. 6b, Fig. 7 shows an embodiment in which each leg 70 comprises an elastically compressible distal end portion 76 that is wider than the opening 130 when uncompressed. After insertion, the distal end portion 76 is compressible to fit into the opening 130. The compressible distal end portion 76 expands upon reaching the wider portion of the opening 130, and presses on the inner walls 132, 134 of the opening 130 to restrict movement of the retainer relative to the cartridge housing.

In another embodiment of the present disclosure shown in Fig. 8, each leg 70 is deformed before insertion to a position offset from the insertion axis X. Upon insertion, the deformed end 77 of the leg 70, which takes up a greater width than the opening 30, engages either of the walls 32, 34 of the cartridge housing opening 30, to restrict movement of the retainer relative to the cartridge housing.

Fig. 9 shows an embodiment of the present disclosure in which the leg 70 of the retainer 50 is shaped to have sharp features along the length of the leg 70 to form, for example, an undulating Z-shape 78. The Z-shape portion 78 has a width smaller than the opening 30. After inserting the leg 70 with the Z-shaped portion 78, the Z-shape portion 78 is compressed via a stop 1 10 to compress the Z-shaped portion 78 of the leg 70 against the walls 32, 34 of the opening 30, thereby a retainer is held in the opening 30 via compressive force. This feature can allow larger openings 30 in the housing for receiving retainers, improving the holdability and hold life of the retainer. In another embodiment as shown in Figs. 10a- lOg and l la-l lg, the retainer 50 has two legs 70 in which each leg has an upper leg portion 70a proximal to the central portion 60 and a lower leg portion 70b. In these examples, a protrusion 72 is disposed on the upper leg portion 70a. Further, as opposed to the retainer shown in Figs. 2a-2e, the protrusion 72 is on an inner side of the upper leg portion 70a instead of an outer portion.

The upper leg portion 70a extends in a first direction, and the lower leg portion 70b extends at an angle to the upper leg portion 70a in a second direction different the first direction. In examples 10a- lOg, the lower leg portions 70b extend inwards towards each other. In examples 1 la-1 lg, the lower leg portions 70b extend outwards and away from each other.

In another embodiment shown in Fig. 12, the retainer 50 has lower leg portions 70b that extend outwards and away from each other in a direction perpendicular to the upper leg portion 70a. In another embodiment shown in Fig. 13, the retainer 50 has lower leg portions 70b that extend inwards and toward each other in a direction perpendicular to the upper leg portion 70a. The purpose for this arrangement is so that the lower leg portion 70b engages a bottom surface of its respective cartridge housing 20 to secure the retainer in the cartridge housing 20.

The present disclosure can be practiced by employing conventional materials, methodology and equipment. Accordingly, the details of such materials, equipment and methodology are not set forth herein in detail. In the previous descriptions, numerous specific details are set forth, such as specific materials, structures, chemicals, processes, etc., in order to provide a thorough understanding of the present teachings. However, it should be recognized that the present teachings can be practiced without resorting to the details specifically set forth, i other instances, well known processing structures have not been described in detail, in order not to unnecessarily obscure aspects of the present teachings.

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.