Patent Publication Number: US-11642804-B2

Title: Shaving systems

Description:
RELATED APPLICATIONS 
     This application is a continuation application of U.S. patent application Ser. No. 16/698,605, filed Nov. 27, 2019, which is a continuation application of U.S. patent application Ser. No. 16/032,112, filed Jul. 11, 2018, now U.S. Pat. No. 10,507,588, issued Dec. 17, 2019, which is a continuation application of U.S. patent application Ser. No. 15/298,457, filed Oct. 20, 2016, now U.S. Pat. No. 10,052,776, issued Aug. 21, 2018, which is a continuation of U.S. patent application Ser. No. 13/929,340, filed Jun. 27, 2013, now U.S. Pat. No. 9,486,930, issued Nov. 8, 2016, which claims priority of U.S. Provisional Application Ser. No. 61/706,523, filed on Sep. 27, 2012. The complete disclosures of these applications are hereby incorporated by reference herein. 
    
    
     BACKGROUND 
     The invention relates to shaving systems having handles and replaceable blade units. Shaving systems often consist of a handle and a replaceable blade unit in which one or more blades are mounted in a plastic housing. After the blades in a blade unit have become dull from use, the blade unit is discarded and replaced on the handle with a new blade unit. Such systems often include a pivoting attachment between the blade unit and handle, which includes a pusher and follower configured to provide resistance during shaving and return the blade unit to a “rest” position when it is not in contact with the user&#39;s skin. 
     SUMMARY 
     In general, the present disclosure pertains to shaving systems and to replaceable shaving assemblies for use in such systems. The systems include a flexible return element, e.g., of an elastomeric material, which provides the resistance and return force that are often provided by a pusher and follower mechanism in prior art shaving systems. 
     In one aspect, the invention features a replaceable shaving assembly that includes a blade unit and an interface element configured to removably connect the blade unit to a handle, on which the blade unit is pivotably mounted. The interface element includes spaced apart rigid portions connected by a flexible return element, the return element providing a pivoting connection between the blade element and handle. 
     Some implementations include one or more of the following features. A handle interface element configured to receive the handle may extend from one of the rigid portions, and a blade unit interface element configured to be mounted on the blade unit may extend from the other rigid portion. The return element may comprise two spaced apart elastomeric members that extend in a direction generally perpendicular to a longitudinal axis of the blade unit, and each of the elastomeric members may connect a pair of the spaced apart rigid portions. The return element may be configured to bias the blade unit towards a rest position with respect to a pivot axis that is generally parallel to a long axis of the blade unit, and is preferably pretensioned. The return element may be formed of an elastomeric material, e.g., a thermoplastic elastomer or thermoplastic urethane. The return element is generally molded onto the interface elements, e.g., by an overmolding process. In some cases, the return element includes two generally H-shaped portions. The rigid portions include corresponding protrusions, which extend toward each other and are embedded in the return element. In some cases, anchoring areas are provided in the protrusions, e.g., holes into which the elastomeric material of the return element can flow during overmolding. 
     In another aspect, the invention features a shaving system that includes a handle having a distal end and a proximal end, and a shaving assembly, mounted on the distal end of the handle, the shaving assembly including an interface element configured to connect the blade unit to the handle, and a blade unit that is pivotably mounted on the interface element. The interface element includes a pair of spaced apart rigid portions connected by a flexible return element, the return element providing a pivoting connection between the blade element and handle. 
     Some implementations of this aspect can include any one or more of the features discussed above with regard to the shaving assembly. In some cases, the shaving assembly is removably mounted on the handle via the interface element and is replaceable. 
     The invention also features methods of shaving. For example, in one aspect the invention features a method of shaving comprising contacting the skin with the blade unit of a shaving system comprising a handle having a distal end and a proximal end, and a replaceable shaving assembly that includes a blade unit, and an interface element configured to removeably connect the blade unit to a handle, on which the blade unit is pivotably mounted, the interface element comprising a pair of spaced apart rigid portions connected by an elastomeric element, the elastomeric element providing a pivoting connection between the blade element and handle. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of an assembled shaving system according to one embodiment. 
         FIG.  2    is a rear plan view of the assembled shaving system. 
         FIG.  3    is a side plan view of the assembled shaving system. 
         FIG.  4    is an exploded view of the shaving system. 
         FIG.  5    is a view of the handle interface element, the return element, and the blade unit interface element of the shaving system shown in  FIG.  1   . 
         FIG.  5 A  is a view of the handle interface element and the blade interface element. 
         FIG.  5 B  is a perspective view of the handle interface element, blade interface element, and handle, with the return element omitted to show the spacing between the handle interface element and blade interface element. 
         FIG.  6    is a perspective view of the handle interface element, the return element, and the blade unit interface element. 
         FIGS.  7  and  8    are alternate views of the handle interface element, the return element, the blade unit interface element, and the blade unit housing. 
         FIG.  9    is a perspective view of a shaving system according to an alternate embodiment. 
         FIGS.  10  and  10 A  are enlarged perspective views of the handle interface element, the return element, the blade unit interface element, and the blade unit of the shaving system shown in  FIG.  9   . 
         FIG.  11    is a perspective view of the handle interface element, the return element, and the blade unit interface element. 
         FIG.  11 A  is a view of the handle interface element and blade interface element. 
         FIG.  12    is a perspective view of the handle interface element, the blade unit interface element, and the return element, taken from the opposite side. 
         FIG.  13    is a series of diagrammatic views illustrating how the angle of the blade unit with respect to the handle is measured. 
         FIG.  14 - 14 A  are perspective views of an embodiment in which the shaving assembly is designed to be permanently attached to the handle. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure relates generally to consumer products and, in particular, to shaving systems with interchangeable blade units. In one embodiment, the present disclosure features a reusable consumer product system having an interchangeable pivoting blade unit, which includes a return element. For example, the present disclosure could include a system having a blade unit attached to a handle in part by elongated elastomeric members that provide the resistance and return force usually supplied by a pusher/follower assembly. 
       FIG.  1    shows a shaving system  10  that includes a handle  12 , a handle interface element  14 , a return element  16 , a blade unit interface element  18  and a blade unit  20  which includes a plurality of blades  22 . Pivoting of the blade unit  20  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  20  to follow the contours of a user&#39;s skin during shaving. Generally, the handle interface element  14 , the return element  16 , the blade unit interface element  18  and blade unit  20  are sold to the consumer as an integrated replaceable shaving assembly. Preferably the angle of blade unit  20  with respect to handle  12  is 65° but can range from approximately 15° to 105° ( FIG.  13   ). 
     Referring to  FIG.  4   , the blade unit  20  is mounted on blade unit interface element  18  by the positioning of a pair of fingers  30  which extend from the blade unit interface element  18  into receiving bores  35  on the blade unit  20 . The receiving bores  35  may be molded integrally with the blade unit  20 . In addition, the blade unit interface element  18  includes tabs  25 A and  25 B ( FIG.  6   ) that serve as complementary attachment points for the blade unit  20 . The blade unit pivot stop  32  is integrally formed with the blade unit  20  and extends generally perpendicular to the long axis of the blade unit  20 . The blade unit pivot stop  32  limits the pivoting of the blade unit  20 . 
     Referring to  FIG.  5 A , the handle interface element  14  is made up of a handle interface portion  26  and two protrusions  27 A and  27 B. The protrusions  27 A and  27 B extend generally perpendicular to the long axis of the handle interface portion  26 . The blade unit interface element  18  has two protrusions  19 A and  19 B that correspond to and align in a similar plane as the two protrusions  27 A and  27 B on the handle interface portion  26 . 
     Referring to  FIGS.  5 - 7   , the handle interface element  14  is flexibly joined to the blade unit interface element  18  by the return element  16 . The return element  16  consists of a pair of elongated elastomeric members  116 A and  116 B, which connect protrusions  19 A and  19 B to protrusions  27 A and  27 B. The return element  16  serves as a pivot and provides resistance during shaving, limiting the free pivoting of the blade unit about the pivot axis described above. In addition, the return element  16  provides a return force that biases the blade unit  16  towards its rest position, in the same manner that resistance and return force are typically provided by a pusher/follower assembly. 
     Referring to  FIG.  8   , the elongated members  116 A and  116 B are pretensioned when the blade unit is in its at rest position by bending of the elastomer over the blade unit. This pretensioning is the result of the angle at which the components are molded and the geometry of the return element, which are selected so that when the interface element is assembled onto the blade unit the return element is pretensioned. Pretensioning provides a resistance force so that a load is applied as soon as the user starts shaving, balancing the blade unit. 
     The return element  16  may be integrally molded with the handle interface element  14  and the blade unit interface element  18 , e.g., by co-molding the elastomer with the rigid plastic(s). It is noted that the term “co-molding,” as used herein, includes transfer molding and other techniques suitable for molding two or more different materials into a single part. Molding is facilitated by an opening  29  in the handle interface element  14  through which the elastomeric material can be injected so that it molds around the protrusions  27 A and  27 B shown in  FIG.  5 A . Preferably, during co-molding, there is a gap  31  ( FIG.  5 B ) between the blade unit interface element  18  and the handle interface element  14 . This gap allows the two interface elements to be flexibly joined by the elastomer. In some implementations the gap is from about 1 mm to 15 mm, preferably about 3 to 10 mm. Molding the return element  16  in this manner results in an elastomeric anchor  24 , which fills the opening  29 . Thus, molding may be a three-shot process in which the interface elements are molded first in two separate shots, followed by the elastomer. 
     The return element  16  can be formed, for example, from synthetic or natural rubber materials. Suitable materials are well known in the shaving system art, and 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 GLS PolyOne 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 90 Shore A, e.g., from about 18 to 80 Shore A, preferably from about 30 to 60 Shore A. 
     The return element  16  is designed such that its geometry provides an applied load as assembled that is sufficient to overcome the friction of the system at rest (pretensioned load), typically at least 5 grams, e.g., 5 to 30 grams, and a load during shaving of from about 10 to 100 grams. 
     The handle  12  provides a manner in which the shaving system can be manipulated and leverage can be applied to achieve desired shaving results. Referring to  FIG.  4   , the handle  12  can be designed to interface with the handle interface element  14  in such a manner that would enable easy removal and attachment. This could be accomplished in a number of manners, such as a mechanical locking mechanism, magnetic interaction, etc. For example, the handle interface element  14  and handle  12  can interface in the manner discussed in U.S. Ser. No. 61/651,732, filed May 25, 2012, the full disclosure of which is incorporated herein by reference. 
     The handle  12 , blade unit  20 , blade interface element  18 , and handle interface element  14  can be made of any suitable material including, for example, polyethylene terephthalate (PET or PETE), high density (HD) PETE, thermoplastic polymer, polypropylene, oriented polypropylene, polyurethane, polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyester, high-gloss polyester, metal, synthetic rubber, natural rubber, silicone, nylon, polymer, antibacterial or antimicrobial materials, insulating, thermal, or other suitable sustainable or biodegradable materials, or any combination thereof. 
       FIGS.  9 - 12    show a shaving system  55  according to another embodiment. In this embodiment, the return element  65  includes a pair of elastomeric members  66 A,  66 B each of which is formed in the shape of an “H.” As was the case in the embodiment shown in  FIG.  1   , the return element  65  provides an interface piece, connector and pivot all in one. The other aspects of the return element  65 , the handle interface element  60 , the blade unit interface element  70 , the gap  71 , and the blade unit  75  are the same as those in the embodiment mentioned previously. As discussed above, the elastomer may be co-molded with, or over-molded onto, the blade unit interface element and handle interface element. The flow path  141  of the elastomer is shown in  FIG.  12   . 
     Also, while removable shaving assemblies have been discussed above, in some implementations the shaving system is designed to be disposable as a whole. In these cases, the shaving assembly is affixed to the handle in a manner that is not intended for the consumer to remove, e.g., by fixedly mounting the interface element on the distal end of the handle. This may be accomplished, for example, by engagement of corresponding mechanical locking features on the handle and interface element  144 , by welding (e.g., ultrasonic welding), by molding the interface element integrally with the handle, or by any other desired mounting technique. An example of a disposable shaving system  100  is shown in  FIG.  14   , and the shaving assembly for such a system is shown in  FIG.  14 A . In this case, the handle  112  includes protrusions  150  (only one of which is shown, the other being on the opposite side of the handle), and the interface element includes corresponding locking indentations  152 . 
     A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. 
     For example, in some embodiments through holes are provided in the portions of the interface elements over which the elastomer is molded. These holes extend in the direction of mold action, so that the elastomer will flow through the holes thereby anchoring the elastomer in place on the underlying interface elements. Alternatively, other anchoring techniques can be used. 
     Accordingly, other embodiments are within the scope of the following claims.