Abstract:
Connecting structures are provided, for connecting a cartridge to a handle in a shaving razor, e.g., a razor for wet shaving. A cartridge connecting a structure includes a molded body, and a blade unit receiving portion having a shell bearing structure that pivotally receives a blade unit, the shell bearing structure comprising a pair of shell bearings. The cartridge connecting structure further includes a spring return for biasing the blade unit relative to the cartridge connecting structure, the spring return being positioned between the shell bearings and extending integrally from the molded body of the cartridge connecting structure.

Description:
TECHNICAL FIELD 
     This invention relates to shaving razors having replaceable cartridges, and cartridges for such razors. 
     BACKGROUND 
     Shaving systems often consist of a handle and a replaceable cartridge in which one or more blades are mounted in a plastic housing. After the blades in a cartridge have become dull from use, the cartridge is discarded, and replacd on the handle with a new cartridge. In some shaving systems the connection of the cartridge to the handle provides a pivotal mounting of the cartridge with respect to the handle so that the cartridge angle adjusts to follow the contours of the surface being shaved. In such systems, the cartridge can be biased toward an at rest position by the action of a spring-biased plunger (a cam follower) carried on the handle against a cam surface on the cartridge housing. 
     SUMMARY 
     In one aspect, the invention features, in general, a replaceable razor blade cartridge that includes a blade unit and cartridge connecting structure for connecting the blade unit to a handle. The cartridge connecting structure has inwardly directed surfaces that partially define a handle-receiving region and mate with outwardly directed surfaces on a handle connecting structure of the handle. The cartridge connecting structure also has a connection entrance to the handle-receiving region, and a projection that extends into the handle-receiving region. The projection has a blocking surface facing the opposite direction from the connection entrance to retain the handle connecting structure on the cartridge connecting structure. The cartridge connecting structure also includes a blade unit receiving portion having a shell bearing structure that pivotally receives the blade unit. 
     Certain implementations of the invention include one or more of the following features. In certain implementations the cartridge connecting structure includes a latching member having a projection with a blocking surface that blocks retraction of the handle connecting structure from the cartridge connecting structure when in a latched position and permits retraction of the handle connecting structure from the cartridge connecting structure when in an unlatched position. The latching member may include engagement structure that is movable from an initial position to a deflected position, the blocking surface moving from the latched position to the unlatched position as the engagement structure is moved from the initial position to the deflected position. The handle connecting structure of the handle may have an ejector that is extendible from the handle, and the engagement structure may be aligned with the ejector. The cartridge connecting structure may include a spring return, e.g., a spring having a bent portion. 
     In another aspect, the invention features, in general, shaving razors including cartridges as have already been described and handles connected to the cartridges. 
     In another aspect, the invention features, in general, methods of connecting replaceable shaving cartridges as have already been described to handles and disconnecting the cartridges from the handles by moving latching members to release the cartridges from the handles. 
     Embodiments of the invention may include one or more of the following advantages. The use of a latching member permits the cartridge to be securely attached to the handle with little likelihood of unintended detachment during use. In addition the cartridge can be released and removed from the handle with little force when it is desired to replace the cartridge. 
     The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will be apparent from the description and drawings, and from the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of the head and neck portion of a razor according to one embodiment of the invention. 
       FIG  1 A is a perspective view of the head and neck portion shown in  FIG. 1 , viewed from the back. 
         FIG. 2  is an exploded perspective view of the razor of  FIG. 1 . 
         FIGS. 3 and 3A  are perspective views of a connecting member used to connect the cartridge to the handle in the razor shown in  FIG. 1 , taken from different angles. 
         FIGS. 4 and 4A  are, respectively, perspective and end views of the blade unit of the razor shown in  FIG. 1 . 
         FIG. 5  is a perspective view, taken from the rear, of the blade unit of  FIGS. 4 and 4A  connected to a handle by the connecting member shown in  FIGS. 3 and 3A . 
         FIGS. 6-6B  are, respectively, exploded, top and side views of a handle connecting structure at the upper end of the handle shown in  FIG. 2 . 
         FIG. 7  is a cross-sectional view of the rear portion of the connecting member shown in  FIGS. 3-3A . 
         FIG. 8  is a cross-sectional view of the corresponding portion of the handle connecting structure shown in  FIGS. 6-6A , taken along line  8 - 8  in  FIG. 6A . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 and 2 , a shaving razor  10  includes a disposable cartridge  12  and a handle  14 . As shown in  FIG. 2 , cartridge  12  includes a connecting member  18 , which removably connects cartridge  12  to a connecting portion  19  of handle  14 , and a blade unit  16 , which is pivotally connected to connecting member  18 . Optionally, the cartridge may include a shaving aid holder  30  mounted on the blade unit  16 . Shaving aid holder  30  is described in U.S. Ser. No. 10/969,373, titled Shaving Razors and Cartridges, filed on the same date as this application. Referring to  FIG. 1 , the blade unit  16  includes a plastic housing  20 , a guard  22  at the front of housing  20 , and blades  28  between guard  22  and the rear of housing  20 . 
     The blade unit  16  is similar to blade units described in U.S. Pat. No. 5,661,907, the complete disclosure of which is incorporated herein by reference. The handle  14  is similar to those described in U.S. Pat. Nos. 5,855,071, 5,956,851 and 6,052,903, the complete disclosures of which are incorporated herein by reference. The connecting member  18  that is used to connect blade unit  16  to handle  14  is discussed below. 
     As discussed above, referring to  FIGS. 1 and 2 , razor  10  includes a disposable cartridge  12  and a handle  14 . As shown in  FIG. 2 , cartridge  12  includes a connecting member  18 , which removably connects cartridge  12  to a connecting portion  19  of handle  14 , and a blade unit  16 , which is pivotally connected to connecting member  18 . 
     Connecting member  18  is shown in detail in  FIGS. 3-3A . Connecting member  18  includes a base  127 , which removably and fixedly attaches to an extension  126  ( FIG. 6 ) on handle  14 , and two arms  128  that pivotally support blade unit  16  at its two sides, as shown in  FIG. 5 . Thus, base  127  connects to the connecting portion  19  of handle  14 , while arms  128  connect to the blade unit  16 , as will be discussed in further detail below. A flexible spring return  145  extends from base  127  and acts against a cam surface on blade unit  16 , causing the blade unit  16  to have a forward-biased at-rest orientation. As shown in  FIG. 2 , the spring return includes a bend  200  that facilitates molding of the base  127 . 
     First, the connection of the arms  128  to the blade unit  16  will be described, with reference to  FIGS. 3-5 . 
     Referring first to  FIG. 4A , extensions  134 ,  136  are located at the bottom of housing  20  of the blade unit. Extensions  134 ,  136  carry inwardly extending opposed curved rails  138 ,  141  having respective curved surfaces  420 ,  440 . The undersurfaces  460 ,  480  of housing  20  are similarly curved and provide, with extensions  134 ,  136 , a pivotal connecting structure, as described in detail in U.S. Pat. Nos. 4,488,357; 4,498,235; 4,492,025; 4,573,266; 4,586,255, 4,756,082 which are hereby incorporated by reference. 
     The curved rails  138 ,  141 , in conjunction with undersurfaces  460 ,  480  of housing  20 , define arcuate slots  98 ,  100 , which are adapted to receive arms  128  of connecting member  18  ( FIG. 3 ). Arms  128  define shell bearing surfaces which engage undersurfaces  460 ,  480 . Thus, arms  128  or “shell bearings” cooperate with the surfaces  460 ,  480  to facilitate pivotal connection of the blade assembly to the razor handle  14 . This mating engagement is referred to herein as a “shell bearing connection.” 
     The top surfaces of rails  138 ,  141  and housing undersurfaces  460 ,  480  have radii of curvature about a pivot axis, which may be, for example, located at the cutting edge of the second blade  201  of the blade unit ( FIG. 4 ). The curved surfaces  420 ,  440  of extensions  134 ,  136  are similarly curved about the pivot axis. Shaving aid holder  30  includes cut out areas (not shown) to provide clearance for the pivoting movement provided by these complementary surfaces. 
     The shell bearings have stop surfaces (not shown) that provide a forward pivot stop position and a rearward pivot stop position, as described in U.S. Pat. No. 5,661,907. The shell bearings also have recesses (not shown) that mate with stop surfaces  135 ,  137  ( FIG. 4A ) formed on the respective curved undersurfaces  460 ,  480  to complement the rearward pivot stop position to prevent further “downward” travel. 
     Referring to  FIG. 4 , cam surface  250  is formed in the bottom of housing  20 . Surface  250  has two oppositely inclined surfaces of the same size and an apex located at a position midway between the front and the back of cam surface  250 . Cam surface  250  permits the blade unit to pivot forward or rearward to the same extent during shaving, and is adapted to receive spring  145  to bias the cartridge within the range of overall rotation, e.g., through a 40 to 45 degree arc. 
     Now, the connection of the base  127  to the connecting portion  19  of handle  14  will be described, with reference to  FIGS. 3-3A  and  6 - 8 . 
     Referring to  FIGS. 3A and 7 , base  127  has a handle-receiving region  132  that is partially defined by inwardly directed surfaces  134 . Connection entrance  136  ( FIG. 7 ) provides access to handle-receiving region  132 . Inwardly directed surfaces  134  mate with outwardly directed surfaces  138  ( FIG. 8 ) on extension  126  of handle  14 . Base  127  also has an angled recess region  140  for receiving angled surface  142  on handle  14 . 
     Referring to  FIGS. 3A and 8 , base  127  has a latching member  244  formed in the bottom wall  246  of the base. Latching member  244  has a cantilevered beam structure, and is connected to bottom wall  246  at base region  248 . Latching member  244  tends to pivot upon being subjected to a force with an outward component at the free end at engagement members  154  (i.e., to the left along connection axis  76  in  FIG. 7 ), as described in U.S. Pat. No. 5,956,851, incorporated by reference above. Bottom wall  246  also has grooves  256  to promote pivoting of latching member  44 . 
     Two projections  158  ( FIGS. 3A and 7 ) extend upward from latching member  244  for interacting with depressions  160  formed in the lower surface of extension  126  of handle  14  ( FIG. 8 ). Each projection  158  has a front blocking surface  162 , a top surface  164 , and an angled camming surface  166 , which makes about a 45 degree angle with connection axis  76  along which extension  126  moves during connection to and retraction from base  127 . Other angles, e.g., between 30 and 60 degrees, could also be used. Depressions  160  similarly have front surfaces  168  for interacting with front blocking surface  162 , top surface  170  and rear angled surface  172  for receiving top surface  164  and camming surface  166 , respectively, of projections  158 . Front blocking surface  162  of projection  158  makes about a 90 degree angle with connection axis  76 . 
     The interaction of the components of handle  14  and cartridge  12  during connection and disconnection of cartridge  12  to handle  14  is discussed in further detail in U.S. Pat. No. 5,956,851, the disclosure of which is incorporated by reference above. Briefly, as extension  126  of handle  14  is moved into the handle-receiving region  132 , sloping surface  90  ( FIG. 8 ) of extension  126  rides over camming surface  166 . This causes latch member  244 , and in particular projection  158  thereon, to move downward along a deflection axis which is substantially perpendicular to connection axis  76  and the direction of insertion. 
     When sloping surface  90  has advanced past projection  158 , and latching member  244  has moved up to the latched position in which projection  158  has snapped up into depression  160  of extension  126 , cartridge  12  is securely attached to handle  14  with little likelihood of unintended detachment during use. The attachment is particularly secure due to interference of surface  168  ( FIG. 8 ) on handle  14  with blocking surface  162  ( FIG. 7 ) on cartridge  12 . Surfaces  162  and  168  are substantially perpendicular to axis  76  along which extension  126  needs to be moved relative to base  127  to disconnect the two. Thus very large forces along axis  76  would need to be exerted to disconnect cartridge  12  from handle  14  if one does not first unlatch latching member  244 . 
     The connecting portion  19  of handle  14  is shown in detail in  FIGS. 6-6B  and  8 . Referring to  FIG. 6 , a cartridge support structure  142  extends from the end of handle  14 . Cartridge support structure  142  includes the trapezoidal extension  126 , discussed above, and components that provide for ejection of cartridge  12  from handle  14 . 
     Spring-biased plunger  144 , spring  146 , and U-shaped ejector  148  are received within recess  149  of cartridge support structure  142 . Ejector button  150  is received in opening  152  on the top surface of support structure  142  and has bottom extensions  154  that are received within rectangular region  156  at the back narrow portion of ejector  148 . These components are described in detail in U.S. Pat. No. 5,855,071, the disclosure of which was incorporated by reference above. Ejector  148  is slidably mounted within a recess within the handle connecting structure of handle  14 , and can be moved forward slightly by activating button  150  on handle  14 . 
     When the user wishes to disconnect cartridge  12  from handle  14 , button  150  is moved relative to extension  126  in the unlatched direction, and this causes ejector  148  to be moved along axis  76  in the ejection direction. Ejector  148  ( FIG. 8 ) pushes engagement members  154  outward, causing projection  158  to move downward as latching member  244  bends at base region  248 . This downward movement causes projection  158  to clear depression  160  and to release extension  126  from latching member  244  so that extension  126  moves relative to base  127  in the retraction direction. A new cartridge may then be mounted on the handle by inserting the connecting portion  19  of the handle into the handle-receiving region  132  as discussed above. 
     A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.