Patent Description:
Such razors often include a pivoting attachment between the blade unit and an interface element that connects the blade unit to the handle. The blade unit and interface element are typically sold as an assembled unit, referred to herein as a shaving assembly.

In some cases, pivoting is provided by interaction between arms or stanchions that extend from the interface element and mating elements on the blade unit, for example, fingers disposed on the arms that are received by bores in mounting elements extending from the blade unit toward the interface element. Providing proper tolerances to allow the blade unit to be assembled onto the interface element, with the fingers properly inserted in the bores, can prove challenging in a high speed manufacturing setting. <CIT> discloses a razor head where a resiliently deformable material is used in order to allow a pivoting movement of the razor head during sahving and in order to bring back the razor head to a normal position when the force is removed. <CIT> discloses a razor blade unit, in which a blade housing is connected to a coupling means via an integral hinge, wherein the integral hinge is surrounded by a dampening component in order to provide force transmission and pivot-dampening.

The present disclosure features shaving razors and shaving assemblies in which features are provided that facilitate assembly of the blade unit onto the interface element, while also, in some implementations, providing advantageous mechanical properties to the arms.

The invention features a replaceable shaving assembly as defined in independent claim <NUM>.

According to the present invention, the elastomeric layer includes a groove. The groove extends circumferentially around the entire arm, or the groove is disposed on an inner surface of each arm, facing the other arm, or is disposed on an outer surface of each arm, facing away from the other arm. Some implementations include one or more of the following features. The elastomeric outer layer may completely or partially surround the post. The post has an assymetric cross-section, e.g., rectangular or elliptical. Alternatively, the post may have a symmetric cross-section, e.g., circular or square. In some embodiments, the groove also extends rearwardly around at least a portion of the arm. The post may be tapered along its length, and/or include a notch disposed along its length. The arms may also include structures to facilitate pivoting, for example a finger extending from a distal end of each arm or a shell bearing member extending from a distal end of each arm.

In another aspect, the disclosure features a shaving razor as defined in claim <NUM>.

This aspect may include any one or more of the features discussed above with regard to the shaving assembly.

Referring to <FIG>, a razor <NUM> includes a handle <NUM> and, mounted at a distal end of the handle, a shaving assembly <NUM>. The shaving assembly <NUM> includes a blade unit <NUM> pivotably mounted on an interface element <NUM>. The interface element <NUM> may be mounted on the handle in any desired manner. In some implementations mounting is accomplished using a magnetic attachment system that includes magnetic and ferrous elements. In some implementations, a magnetic element is associated with an appendage (not shown) at the distal end of the handle and a ferrous element is associated with the receiving portion of the interface element <NUM>, e.g., as disclosed in <CIT>, the full disclosure of which is incorporated herein by reference. Generally, the interface element <NUM> and blade unit are sold to the consumer as an integrated replaceable shaving assembly.

The shaving assembly <NUM> also includes an elastomeric return element <NUM>, which is similar to the elastomeric return element described in <CIT>, the full disclosure of which is incorporated herein by reference. The elastomeric return element includes a central portion <NUM> that extends generally parallel to the longitudinal axis of the blade unit, and abuts a surface of the blade unit to provide a return force to the blade unit after a shaving stroke. The elastomeric return element <NUM> extends from the interface element <NUM> to contact a rear surface of the blade unit <NUM>, and is generally integrally formed with the interface element. For example, the elastomeric return element may be co-molded with or insert molded onto the interface element which is generally formed of a hard thermoplastic.

The blade unit <NUM> is mounted on interface element <NUM> by the engagement of a pair of fingers <NUM> in corresponding bores <NUM>. Fingers <NUM> are disposed on arms <NUM> extending from the interface element <NUM>, and are received in bores <NUM> disposed in mounts <NUM> (<FIG>) extending from the blade unit <NUM>. The mounts <NUM> are generally molded integrally with the blade unit and the arms <NUM> are generally molded integrally with the interface element.

The engagement of fingers <NUM> in bores <NUM> allows pivoting of the blade unit with respect to the interface unit and thus the handle. Pivoting of the blade unit is about an axis that is generally parallel to the long axis of the blade unit and is generally positioned to allow the blade unit to follow the contours of a user's skin during shaving. This general type of pivoting arrangement is well known in the razor art.

As discussed above, the shaving assembly <NUM>, which consists of the interface element and blade unit, is typically sold to the consumer as an assembled unit. Accordingly, the blade unit is mounted on the interface element during the manufacturing process, which involves bending the arms inward so that the fingers <NUM> can snap into bores <NUM>.

In the implementation shown in <FIG>, each arm <NUM> includes a generally rectangular internal post <NUM> (<FIG>) on which the portion carrying finger <NUM> is mounted. Post <NUM> is surrounded by elastomeric material <NUM> (<FIG>), which supports and protects the post <NUM> during flexing, and provides the arm with desired flexural properties. The elastomeric material surrounding the post may be formed of the same elastomer as the elastomeric return elements, in which case the elastomer typically flows from the same anchor region within the interface element.

The thickness of the elastomeric material is the difference of the thermoplastic post inside and the aesthetic shape of the arms outside. The thickness of the elastomeric material does not need to be uniform, and can be selected so as to provide the arms with an aesthetic shape. The thickness of the post and the presence or absence of any features on the post, such as grooves or notches, has a greater effect on the flexural properties of the arms than the geometry of the thermoplastic layer.

The elastomeric material <NUM> of each arm includes an internal groove <NUM>, disposed to face towards the opposite arm, that facilitates inward flexure of the arm during assembly. The internal groove <NUM> is molded into the elastomeric material <NUM>, providing a notch that favors bending of the arm inward, and biases the arm back towards its normal position when the bending force is released. In some implementations, the groove has a depth that is from about <NUM>% to <NUM>% of the elastomer thickness in that region, e.g., from about <NUM>% to <NUM>%.

As can be seen in <FIG>, in this implementation the post <NUM> is narrow in the direction parallel to the length of the blades, and wider in the direction perpendicular to the length of the blades. For example, the narrow dimension (parallel to the length of the blade unit, as shown in <FIG>) could be from about <NUM> to <NUM> and the wider dimension (<FIG>) may be from about <NUM> to <NUM>. The width in the direction perpendicular to the blade length stiffens the arms in direction A to help the arms resist shaving forces, while the narrowness in the perpendicular direction allows the arms to flex in direction B to aid assembly of the blade unit onto the interface element to form the shaving assembly.

Thus, the rectangular cross-sectional shape of the post <NUM> provides the arms with differential flex, i.e., allows the arms to be stiff in a front-to-back direction (arrow A in <FIG>) to resist shaving forces, but flexible in a side-to-side direction (arrow B in <FIG>) to aid in assembly of the blade unit onto the interface element during manufacturing. The ability of the arms to flex in direction B also allows for less strict tolerance control during manufacturing.

According to the invention, <FIG> shows an implementation, in which the internal groove <NUM> is replaced by a circumferential groove <NUM>. In this case, the elastomer allows the arms to flex both inwardly and outwardly, but the rectangular cross-section of the post still reduces the forces required in the direction of arrow B in <FIG>, while maintaining stiffness in the direction of arrow A. In all other respects, this implementation is similar to that described above with reference to <FIG>.

<FIG> show another alternate embodiment, in which the elastomeric material includes a partial circumferential groove <NUM>, extending around the rear of the arms (i.e., the side of the arm furthest from the guard <NUM> of the blade unit. ) As shown in <FIG>, the post <NUM> is generally rectangular in cross-section. (Other shapes can be used that are deeper in the direction of arrow A than in the direction of arrow B, e.g., elliptical or egg-shaped. ) As a result, the post shape provides differential flex properties similar to those described above with reference to <FIG>, while the partial circumferential groove in the elastomer positioned on the outside and rearward portions of the arm allows for sufficient flex during assembly and some flex in the shaving direction to provide cushioning of shaving forces.

<FIG> show a further alternate embodiment, not covered by the current invention, in which the arms do not have any groove in the elastomeric material. This embodiment simplifies manufacturing and provides the shaving assembly with a clean look from an aesthetic perspective.

Referring to <FIG>, in another implementation the arms <NUM> include posts <NUM> that are cylindrical (has a circular cross-section), rather than having a rectangular cross-section. Because the post has a symmetrical cross-section the flex is not differential, but rather is the same regardless of the direction of applied force.

In the embodiment shown in <FIG>, a cylindrical post <NUM> is used with a circumferential groove <NUM>, combining the features of the embodiments shown in <FIG> and <FIG>. In this embodiment, as in the embodiment shown in <FIG>, flex is not differential, but will be in the direction of applied force.

While pivoting is provided by a finger/bore arrangement in the embodiments discussed above, other pivoting arrangements can be used. For example, pivoting can be provided by a pair of shell bearing units, as is the case in the implementation shown in <FIG>. Such shell bearing pivoting arrangements are disclosed in copending <CIT>, Attorney Docket No. <NUM>-018P01.

Referring to <FIG> and <FIG>, in this implementation a shell bearing element <NUM> is disposed at a distal end of arm <NUM>, which includes post <NUM> encapsulated in elastomer <NUM>. The elastomeric material is removed for clarity in <FIG>, but surrounds the post <NUM> as in the implementations described above.

When the shaving assembly is assembled, the shell bearing element <NUM> interacts with hooked stanchion <NUM> and shell bearing elements 804A and 804B as described in the application incorporated by reference above. During assembly, it is necessary for the arms <NUM> to flex inward (direction B in <FIG>) in order to clear stanchion <NUM>, while during shaving it is generally preferred that the arms be relatively stiff in the direction of shaving forces (direction A in <FIG>). These competing requirements are accommodated by the differential flex of the arms provided by the rectangular cross-section posts, as discussed above.

Another type of shaving assembly in which the arms described herein can be useful is disclosed in <CIT>. In some embodiments of this type of shaving assembly, the fingers extending from the arms are received in elastomeric loops that extend integrally from the guard of the blade unit. Use of flexible arms in such an arrangement can facilitate assembly, provide a better fit between the fingers and loops, and accommodate tolerance variations.

In all of the embodiments discussed above the elastomeric portion of the arm can be formed, for example, from synthetic or natural rubber materials. Suitable materials include thermoplastic elastomers, for example, polyether-based thermoplastic elastomers (TPEs) available from Kraiburg HTP, thermoplastic urethanes (TPUs), silicones, polyether-based thermoplastic vulcanizate elastomer (TPVs) available from Exxon Mobil Corporation under the tradename Santoprene™. The elastomeric material is selected to provide a desired degree of restoring force and durability. In some implementations, the elastomer has a Durometer of less than about <NUM> Shore A, e.g., from about <NUM> to <NUM> Shore A.

In some implementations, the return element is formed of the same elastomeric material, to facilitate molding. In this case, the material for the elastomeric portions of the arms and the return element may be molded in a single shot such that the elastomeric portions and return element share a common anchor in the interface element.

Alternatively, if it is desired that the elastomeric portions have different characteristics from the return element they may be formed of different materials.

The return elements are generally designed such that their geometry provides an applied load as assembled that is sufficient to return the blade unit to its rest position when not in use, for example, when the handle is being held without any load on the blade unit. Preferably the pretensioned load is typically at least <NUM> grams, e.g., <NUM> to <NUM> grams, and the load during shaving is from about <NUM> to <NUM> grams.

The housing of the blade unit and the interface element can be made of any suitable hard material including, for example, acetal (POM), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate (PET or PETE), high density (HD) PETE, high impact polystyrene (HIPS), thermoplastic polymer, polypropylene, oriented polypropylene, polyurethane, polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyester, high-gloss polyester, nylon, or any combination thereof.

While rectangular and cylindrical posts have been discussed above, the post may have any desired assymetrical shape (e.g., elliptical) for differential flex, or any desired symmetrical shape (e.g., regular polygonal such as square) for uniform flex.

Moreover, while posts having a uniform cross-section have been shown, the post can taper along its length if desired, or can include discontinuities along its length. For example, as shown in <FIG> the post can have a necked-in region <NUM> that has a very thin cross-section. The region <NUM> is weak relative to the rest of the length of the post, and can be designed to snap when the arms are flexed during assembly of the blade unit onto the interface element. Once the region <NUM> has snapped, the flexure of the arms will be dictated entirely by the flexural characteristics of the surrounding elastomer (not shown). This embodiment can allow the arms to have very different flexural characteristics pre-assembly and post-assembly, for example to provide greater compliance during shaving.

In addition, while the elastomeric material is shown as surrounding the post, the elastomeric material can in some embodiments extend only partially around the post, e.g., in only an area that needs to be resiliently supported. The flexural properties of the arm are generally provided primarily by the post, so the design of the elastomeric layer can be dictated at least in part by aesthetics.

Claim 1:
A replaceable shaving assembly comprising:
(a) a blade unit (<NUM>) comprising a plurality of longitudinally extending blades; and
(b) an interface element (<NUM>), configured to removeably connect the blade unit to a handle (<NUM>);
(c) wherein the blade unit (<NUM>) and interface element (<NUM>) include cooperating elements that allow the blade unit to pivot with respect to the interface element (<NUM>), the cooperating elements including a pair of arms (<NUM>, <NUM>, <NUM>, <NUM>) extending from the interface element (<NUM>) towards the blade unit (<NUM>); and
(d) wherein each of the arms (<NUM>, <NUM>, <NUM>, <NUM>) includes a non-elastomeric post (<NUM>, <NUM>, <NUM>, <NUM>) and an elastomeric outer layer (<NUM>) in contact with the post (<NUM>, <NUM>, <NUM>, <NUM>)
(e) characterized in that the elastomeric layer (<NUM>, <NUM>) includes a groove (<NUM>, <NUM>, <NUM>, <NUM>),
- wherein the groove (<NUM>, <NUM>, <NUM>, <NUM>) extends around the entire circumference of the arm (<NUM>, <NUM>, <NUM>, <NUM>),
- or wherein the groove (<NUM>, <NUM>, <NUM>, <NUM>) is disposed on an inner surface of each arm (<NUM>, <NUM>, <NUM>, <NUM>), facing the other arm (<NUM>, <NUM>, <NUM>, <NUM>),
- or wherein the groove (<NUM>, <NUM>, <NUM>, <NUM>) is disposed on an outer surface of each arm (<NUM>, <NUM>, <NUM>, <NUM>), facing away from the other arm (<NUM>, <NUM>, <NUM>, <NUM>).