Abstract:
A rotary electric shaver generally includes a handle assembly having a longitudinal axis, and a head assembly attached to the handle assembly. The head assembly includes a plurality of outer cutters and a plurality of inner cutters. Each of the inner cutters is paired with one of the outer cutters for cooperating to cut hair. The head assembly also includes a tray on which hair cut by a first one of the pairs of cooperating cutters is permitted to commingle with hair cut by a second one of the pairs of cooperating cutters. The head assembly further includes a fastener that extends longitudinally for attachment of the head assembly to the handle assembly such that the tray pivots relative to the handle assembly. The head assembly further includes a biasing element that circumscribes the fastener to bias the tray from a pivoted position into a non-pivoted position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 12/432,602, filed Apr. 29, 2009, entitled “ROTARY ELECTRIC SHAVER”, the disclosure of which is hereby incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    The present invention relates generally to electric shavers and, more particularly, to rotary electric shavers. 
         [0003]    Rotary electric shavers conventionally include a handle and a head mounted on the handle and carrying two or more sets of paired inner and outer cutter blades. The outer cutter blades, which are typically circular in shape, are supported by a frame of the shaver head and typically define the skin contacting surface of the shaver along with the outer surface of the shaver head. Openings or slots formed in the outer cutter allow hair to protrude through the outer cutter below an inner surface thereof as the shaver is moved over a user&#39;s skin. Inner cutter blades are housed in the shaver head below the outer cutter in sliding engagement with the inner surface of the outer cutter. The inner cutter blades are rotatably driven by an electric motor, typically housed within the handle, whereby rotation of the inner cutter acts to cut hairs protruding through the outer cutter. 
         [0004]    In current rotary electric shaver constructions, the frame and the outer cutters together define the outer skin-facing or skin-contacting surface of the shaver, with the outer cutters each extending individually outward of the frame. However, when shaving with a rotary shaver, the outer cutters must pass over the user&#39;s various skin contours. The transition of the outer cutter over the skin surface is thus often not smooth and can be abrupt. The smoother the transition is over the entire skin-facing outer surface of the shaver head (e.g., from the frame to the outer surface of the outer cutter), the more comfortable the shaving experience will be. 
         [0005]    With this current construction, as the shaver is moved over the user&#39;s face the skin is forced up over the edges of the outer cutters. This action causes the skin to drag, or become pinched, and the shaver does not glide smoothly onto the top surface of the outer cutter. 
         [0006]    There is a need, therefore, for a rotary electric shaver that facilitates a smoother, more comfortable shave. 
       SUMMARY OF THE INVENTION 
       [0007]    In one embodiment, a rotary electric shaver generally comprises a handle assembly having a longitudinal axis, and a head assembly attached to the handle assembly. The head assembly includes a plurality of outer cutters and a plurality of inner cutters. Each of the inner cutters is paired with one of the outer cutters for cooperating to cut hair. The head assembly also includes a tray on which hair cut by a first one of the pairs of cooperating cutters is permitted to commingle with hair cut by a second one of the pairs of cooperating cutters. The head assembly further includes a fastener that extends longitudinally for attachment of the head assembly to the handle assembly such that the tray pivots relative to the handle assembly. The head assembly further includes a biasing element that circumscribes the fastener to bias the tray from a pivoted position into a non-pivoted position. 
         [0008]    In another embodiment, a rotary electric shaver generally comprises a handle assembly having a longitudinal axis, and a head assembly attached to the handle assembly. The head assembly includes a plurality of outer cutters and a plurality of inner cutters. Each of the inner cutters is paired with one of the outer cutters for cooperating to cut hair. The head assembly also includes a tray on which hair cut by a first one of the pairs of cooperating cutters is permitted to commingle with hair cut by a second one of the pairs of cooperating cutters. The head assembly further includes a fastener that extends longitudinally for attachment of the head assembly to the handle assembly such that the tray pivots relative to the handle assembly. The head assembly is not attached to the handle assembly other than by the fastener, and the fastener does not pivot relative to the handle assembly when the tray pivots relative to the handle assembly. 
         [0009]    In yet another embodiment, a rotary electric shaver generally comprises a handle assembly having a longitudinal axis, and a head assembly attached to the handle assembly. The head assembly defines a hair pocket and includes a cutter frame assembly covering the hair pocket, a tray defining a bottom of the hair pocket, and a fastener that extends longitudinally for attachment of the head assembly to the handle assembly such that the tray pivots relative to the handle assembly and such that the fastener does not pivot relative to the handle assembly. The cutter frame assembly includes a plurality of pairs of cooperating cutters, a single-piece upper cutter frame defining a plurality of cutters ports, and a lower cutter frame fastened to the upper cutter frame. The cutter frame assembly is configured for displacement from covering the hair pocket such that the upper cutter frame, the lower cutter frame, and the pairs of cooperating cutters move as one conjoint unit when the cutter frame assembly is displaced. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view of one embodiment of a rotary shaver; 
           [0011]      FIG. 2  is an exploded view of the rotary shaver of  FIG. 1  with a portion of a shaver head assembly illustrated in an open configuration; 
           [0012]      FIG. 3  is a perspective view of a head assembly mount of the rotary shaver of  FIG. 1 ; 
           [0013]      FIG. 4  is an exploded view of a hair retention assembly of the rotary shaver of  FIG. 1 ; 
           [0014]      FIG. 5  is a perspective view of a tray of the hair retention assembly of  FIG. 4 ; 
           [0015]      FIG. 6  is a perspective view of a boot of the hair retention assembly of  FIG. 4 ; 
           [0016]      FIG. 7  is an exploded view of a torque transfer assembly of the hair retention assembly of  FIG. 4 ; 
           [0017]      FIG. 8  is an exploded view of a cutter frame assembly of the rotary shaver of  FIG. 1 ; 
           [0018]      FIG. 9  is a perspective view of a lower cutter frame of the cutter frame assembly of  FIG. 8 ; 
           [0019]      FIG. 10  is a perspective view of a cutter holder of the cutter frame assembly of  FIG. 8 ; 
           [0020]      FIG. 11  is a perspective view of an upper cutter frame of the cutter frame assembly of  FIG. 8 ; and 
           [0021]      FIG. 12  is a side elevation view of a cutter case of the cutter frame assembly of  FIG. 8 . 
       
    
    
       [0022]    Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0023]    Referring now to the drawings, and in particular to  FIGS. 1 and 2 , a rotary shaver according to one embodiment is indicated in its entirety by the reference numeral  100 . In the illustrated embodiment, the shaver  100  comprises a handle assembly  102  and a head assembly  104  mounted on the handle assembly  102 . The handle assembly  102  has a first or distal end  106 , a second or proximal end  108 , a lock release button  114  proximate the second end  108 , and a hollow housing  110  extending from the first end  106  to the second end  108 , such that a battery, a motor, and gearing may be housed within the handle assembly  102 . Suitably, the handle assembly  102  has a substantially triangular upper receptacle  112  formed by a head assembly mount  200  that is recessed relative to the second end  108 . It is also contemplated, however, that the handle assembly  102  may house any suitable operational components of the shaver  100  and/or that the receptacle  112  may have any suitable cross-section without departing from the scope of this invention. 
         [0024]      FIG. 3  is an enlarged perspective view of the head assembly mount  200 . In the illustrated embodiment, the head assembly mount  200  comprises a spring seat  202  that extends into the upper receptacle  112  from a central region  204  of an upper surface  206  of the head assembly mount  200  and defines a threaded bore  208 . Three substantially similar drive shafts  210  protrude into the upper receptacle  112  through the head assembly mount  200  in a generally triangular configuration about the spring seat  202 . Additionally, each drive shaft  210  is operatively connected to the motor via the internal gearing within the handle assembly  102 , and each drive shaft  210  comprises a tip  212 , a retaining ring  214  connected to the drive shaft  210 , and a roughened surface  216  formed on an outer surface  218  between the tip  212  and the retaining ring  214 . In one embodiment, the retaining ring  214  is connected to the shaft  210  via a snap-fit (e.g., a snap-fit within a groove of the shaft  210 ). Alternatively, the retaining ring  214  and/or the roughened surface  216  may be connected to the shaft  210  via any suitable fastener. It is also contemplated that the head assembly mount  200  may have any suitable shape and/or may have any suitable drive mechanisms protruding therethrough in any suitable configuration without departing from the scope of this invention. 
         [0025]    In the illustrated embodiment, referring again to  FIG. 2 , the head assembly  104  comprises a hair retention assembly  300  having a circumference sized such that the hair retention assembly  300  is insertable into the upper receptacle  112 , and a cutter frame assembly  400  connected (e.g., hinged) to the hair retention assembly  300  and sized such that the cutter frame assembly  400  substantially covers the hair retention assembly  300 , as described below. 
         [0026]      FIG. 4  is an exploded view of the hair retention assembly  300  positioned atop the head assembly mount  200 . The illustrated hair retention assembly  300  comprises a tray  302 , a boot  304 , a plurality of torque transfer assemblies  306 , and a pivot assembly  308 .  FIG. 5  is an enlarged perspective view of the tray  302 . The illustrated tray  302  comprises a base  310  and a peripheral sidewall  312  projecting from the base  310  such that the base  310  and sidewall  312  together form a hair pocket  314  for collecting hair clippings. The base  310  has a plurality of shaft apertures  316  and a central bore  318 , wherein the shaft apertures  316  are substantially equidistantly spaced about the central bore  318  in a generally triangular configuration that corresponds to the arrangement of the drive shafts  210 . Each shaft aperture  316  is suitably sized to receive one of the drive shafts  210  therethrough, and the central bore  318  is sized to receive the spring seat  202  therethrough. Suitably, the peripheral sidewall  312  of the tray  302  comprises an annular rim  324  extending transversely outward, and a plurality of tab slots  326  arranged below the rim  324  to facilitate supporting the boot  304 , as described below. Optionally, a lock  337  may be positioned proximate the rim  324  to facilitating locking the head assembly  104  to seal the hair pocket  314  (i.e., locking the cutter frame assembly  400  and the hair retention assembly  300  in a closed position), as described below. 
         [0027]    The illustrated base  310  further comprises a plurality of feet  328  projecting from a bottom surface  330  of the base  310  to facilitate maintaining a predetermined minimum spacing between the base  310  and the head assembly mount  200  of the handle assembly  102  when the hair retention assembly  300  is inserted into the upper receptacle  112 . Suitably, a plurality of seals  332  (shown in  FIG. 4 ) may be connected to the bottom surface  330  of the base  310  about the shaft apertures  316  (i.e., via any suitable adhesive and/or mechanical fastener). Each seal  332  comprises a hole  334  (shown in  FIG. 4 ) that is sized to receive one of the shafts  210  such that the seal  332  facilitates preventing hair and/or other debris within the hair pocket  314  from entering the upper receptacle  112  of the handle assembly  102  via the corresponding shaft aperture  316 . 
         [0028]    With particular reference to  FIG. 6 , the illustrated boot  304  is generally triangular and is suitably fabricated from a synthetic or semi-synthetic, organic-based material (e.g., a “rubber” material) such that the boot  304  is stretchable to receive the tray  302  (i.e., to facilitate conforming the boot  304  to a curvature of the tray  302 ). The boot  304  comprises a top edge  336 , a bottom edge  338 , a gripping portion  340 , and a skirt portion  342 . In one embodiment, the gripping portion  340  is formed integrally with the skirt portion  342 . In other embodiments, the gripping portion  340  may be formed separate from and connected to the skirt portion  342  using any suitable fastening technique. The illustrated gripping portion  340  comprises a plurality of inwardly extending tabs  344 , wherein each tab  344  is sized for insertion into one of the tab slots  326  of the tray  302  to facilitate securement of the boot  304  on the tray  302 . In one embodiment, the skirt portion  342  depends from the gripping portion  340  and is sized to loosely grip the tray  302  and to define a plurality of notches  346  that accommodate portions of the handle assembly  102  (e.g., the lock release button  114 ) when the tray  302  is inserted into the boot  304  and the upper receptacle  112 . 
         [0029]      FIG. 7  illustrates an enlarged perspective view of the torque transfer assembly  306 , which generally comprises a cap  348 , a biasing member  350  (e.g., in the illustrated embodiment a coil spring) sized to be inserted into the cap  348 , and a pin  352  sized to seat atop the biasing member  350 . The cap  348  comprises a bottom wall  354  having a port  358 , and a generally cylindrical sidewall  356  extending upward from the bottom wall  354  and having a plurality of longitudinally extending channels  360  formed therein. Suitably, the port  358  is sized to receive the tip  212  of the drive shaft  210  therethrough such that the roughened surface  216  of the drive shaft  210  engages an inner surface  362  of the port  358  and such that the bottom wall  354  of the cap  348  is seated on the retaining ring  214  of the drive shaft  210  to facilitate supporting the torque transfer assembly  306  on the drive shaft  210  and transferring torque from the drive shaft  210  to the cutter frame assembly  400  during a shaving operation. 
         [0030]    The illustrated pin  352  comprises a generally hollow body  368 , an open base  364  at one end, and a tip  366  at the opposite end. The base  364  has a plurality of guides  370  extending transversely outward therefrom, wherein each guide  370  is sized to slide within one of the channels  360  of the cap  348  such that the pin  352  is floatable upward and downward in the cap  348 . Suitably, the body  368  is externally sized (e.g., in transverse cross-section) such that a space is left between the body  368  and the sidewall  356  of the cap  348  when the pin  352  is inserted into the cap  348  to facilitate pivoting movement of the pin  352  within the cap  348 . The body  368  is also sized internally (e.g., in transverse cross-section) to receive the biasing member  350  such that the pin  352  is biased away from the bottom wall  354  of the cap  348 . Additionally, the tip  366  of the pin  352  is generally cross-shaped to facilitate transferring torque from the cap  348  to the cutter frame assembly  400  during a shaving operation, as described below. 
         [0031]    Referring again to  FIG. 4 , the illustrated pivot assembly  308  comprises a resilient biasing element (e.g., a spring  372 ), a fastener (e.g., a screw  376 ), and a washer  378 . The illustrated spring  372  is sized to be seated on the upper surface  206  of the head assembly mount  200  about the spring seat  202 , and the screw  376  is sized for insertion through the washer  378 , through the central bore  318  of the tray  302 , through the spring  372 , and into the threaded bore  208  of the spring seat  202  to facilitate pivotably mounting the tray  302  on the head assembly mount  200  with the spring  372  positioned between the tray  302  and the head assembly mount  200 . Suitably, the washer  378  substantially covers the central bore  318  of the tray  302  to inhibit hair from entering the upper receptacle  112  from the hair pocket  314  via the central bore  318 . 
         [0032]      FIG. 8  is an exploded view of the cutter frame assembly  400 . In the illustrated embodiment, the cutter frame assembly  400  comprises a lower cutter frame  402 , a biasing element  404 , and three cutter holders  406 . The illustrated lower cutter frame  402  comprises (with reference to  FIG. 9 ) three holder supports  408 , each having a generally open-ring shape so as to define a pair of opposed, arcuately-shaped arms  412  extending outward from the base  410  and spaced from each other to further define an opening of the support  408 . Each arm  412  further comprises a sloped inner wall  416  that has an upper surface  418  and a lower surface  420 . The base  410  comprises an upwardly projecting spring seat  422  and a bore  424  extending through the base  410  and the spring seat  422 . Suitably, the biasing element  404  is sized to be seated on the base  410  about the spring seat  422 . 
         [0033]    In the illustrated embodiment of  FIG. 8 , the three cutter holders  406  are substantially similar, and each cutter holder  406  comprises (with reference to  FIG. 10 ) a bowl  426 , a substantially L-shaped pivot arm  428  extending outwardly from the bowl  426 , and a pair of prongs  430  extending obliquely upward from the bowl  426 . The bowl  426  comprises a pair of tracks  432  formed on opposite sides of an outer surface  434  thereof, wherein each track  432  comprises an inlet section  436 , a cove section  438 , and a runner section  440  linking the inlet section  436  to the cove section  438 . Additionally, each prong  430  is spaced apart from the outer surface  434  of the bowl  426  to form a gap  442  between the prong  430  and the outer surface  434 , with the gap  442  being sized to receive the sloped inner wall  416  of the holder support  408 . 
         [0034]    Referring back to  FIG. 8 , the illustrated cutter frame assembly  400  also comprises an upper cutter frame  444 , a plurality of cutters  446 , a plurality of cutter cases  448 , and a fastener  450 .  FIG. 11  is an enlarged perspective view of the upper cutter frame  444 . The illustrated upper cutter frame  444  comprises three cutter ports  452  arranged in a generally triangular configuration, wherein each of the ports  452  is sized to receive one of the cutter cases  448 . Optionally, the upper cutter frame  444  may comprise a threaded central boss  454 , a hinge  456  ( FIG. 8 ), and a locking tab  458  to facilitate connecting the upper cutter frame  444  to the lower cutter frame  402  and/or to the handle assembly  102 . Suitably, the upper cutter frame  444  further comprises at least one locking indicator element (e.g., a structural element such as a dimple  460  and/or indicia) and at least one unlocking indicator element (e.g., a protrusion  462 ) that correspond to each port  452  to facilitate indicating to a user the locked and unlocked positions of the cutter case  448  that corresponds to each port  452 . 
         [0035]    Each of the illustrated cutters  446  comprises a cup-shaped outer cutter  464  ( FIG. 12 ) having a plurality of slits  466  disposed in a skin contacting surface  468  thereof to facilitate receiving hair to be cut. The illustrated cutter  446  also comprises a buffer ring  470 , an inner cutter  472 , and an inner cutter stem  474 , wherein each is sized for disposition within the outer cutter  464 . Suitably, the inner cutter stem  474  may be formed with or connected to a bottom surface  476  of the inner cutter  472  and/or the inner cutter stem  474  may define a socket  478  (e.g., a cross-shaped socket) sized to mate with the tip  366  of the pin  352  from the torque transfer assembly  306  to facilitate drivingly connecting the torque transfer assembly  306  to the cutters  446  such that each inner cutter  472  is operatively connected to a respective one of the drive shafts  210  for conjoint rotation therewith. 
         [0036]    Each cutter case  448  comprises an annular body  480  having a top section  482  and a generally cylindrical bottom section  484 . The top section  482  forms an inner flange  486  (illustrated in  FIG. 8 ) and an outer flange  488  that project transversely inward and outward, respectively, from the bottom section  484 . Suitably, two locking members  490  extend downward from transversely opposite sides of the bottom section  484  to facilitate sliding along the tracks  432  of the corresponding holder  406 , as described below. 
         [0037]    The illustrated top section  482  of the cutter body  480  comprises an annular upper skin contacting surface  492  and a peripheral skin contacting surface  494  circumscribing and depending from the upper skin contacting surface  492 . Specifically, the peripheral skin contacting surface  494  is angled generally transversely outward relative to the upper skin contacting surface  492 . In the illustrated embodiment, the slope of the peripheral skin contacting surface  494  varies (i.e., is non-uniform) about the case  448 , such that a first annular segment  496  of the peripheral skin contacting surface  494  is oriented at a first angle α 1  relative to the upper skin contacting surface  492  and second, and in the illustrated embodiment opposite, annular segment  497  of the peripheral skin contacting surface  494  is oriented at a second angle α 2  relative to upper skin contacting surface  492 , wherein the second angle α 2  is greater than the first angle α 1 . Additionally, a width of the upper skin contacting surface  492  varies (i.e., is non-uniform) about the case  448 , such that a first annular segment  498  of the upper skin contacting surface  492 , which is adjacent the first annular segment  496  of the peripheral skin contacting surface  494 , has a first width W 1  and such that a second annular segment  499  of the upper skin contacting surface  492 , which is adjacent the second annular segment  497  of the peripheral skin contacting surface  494 , has a second width W 2  that is greater than the first width W 1 . 
         [0038]    Suitably, the upper skin contacting surface  492  and/or the peripheral skin contacting surface  494  comprises one or more alignment elements (e.g., an alignment finger  493  in the illustrated embodiment) that facilitates indicating to a user an alignment of the case  448  relative to the locking indicator element (e.g., the dimple  460 ) and/or unlocking indicator element (i.e., the protrusion  462 ) of the upper cutter frame  444 . Additionally, the upper skin contacting surface  492  and/or the peripheral skin contacting surface  494  may include ridges  495  that facilitate enabling a user to grip the case  448 . 
         [0039]    In one embodiment of a method of making a rotary shaver such as the rotary shaver  100 , the head assembly mount  200  is inserted into the second end  108  of the handle assembly  102  and is mounted on the handle assembly  102  via suitable fasteners to form the upper receptacle  112 . When the head assembly mount  200  is fastened to the handle assembly  102 , the drive shafts  210  (i.e., the tips  212 , the retaining rings  214 , and the roughened surfaces  216 ) protrude through the head assembly mount  200  and into the upper receptacle  112  in a substantially triangular configuration, and the spring seat  202  projects into the upper receptacle  112  centrally between the drive shafts  210 . 
         [0040]    To assemble the hair retention assembly  300 , the tray  302  is inserted into the boot  304  such that the boot  304  stretches to conform to the contours of the sidewall  312  of the tray  302  (i.e., such that the gripping portion  340  of the boot  304  firmly grips the sidewall  312 , and the skirt portion  342  of the boot  304  loosely hangs from the gripping portion  340 ), and the tabs  344  of the boot  304  are inserted into the tab slots  326  of the tray  302  to support the boot  304  about the tray  302 . 
         [0041]    With the boot  304  in gripping engagement with the tray  302 , the seals  332  are fastened to the bottom surface  330  of the base  310  of the tray  302  about the shaft apertures  316  such that the holes  334  of the seals  332  are substantially coaxially aligned with the shaft apertures  316 . The spring  372  of the pivot assembly  308  is then seated on the head assembly mount  200  about the spring seat  202 , and the tray  302  is inserted into the upper receptacle  112  such that the spring  372  is substantially coaxially aligned with the central bore  318  of the tray  302  and such that the drive shafts  210  extend through the holes  334  of the seals  332 , through the shaft apertures  316 , and into the hair pocket  314 . Specifically, the tip  212 , the retaining ring  214 , and the roughened surface  216  of each drive shaft  210  are situated within the hair pocket  314  of the tray  302 . 
         [0042]    With the tray  302  positioned within the upper receptacle  112 , the spring  372  biases the tray  302  away from the head assembly mount  200  to space the feet  328  of the tray  302  a distance apart from the head assembly mount  200 . The screw  376  is then inserted through the washer  378 , through the central bore  318 , through the spring  372 , and into the threaded bore  208  of the spring seat  202  to secure the tray  302  to the head assembly mount  200  such that the washer  378  substantially covers the central bore  318 . The screw  376  is then tightened such that a space is left between the feet  328  of the base  310  and the head assembly mount  200  to facilitate permitting the tray  302  to pivot about the spring seat  202  (i.e., about a longitudinal axis Y (shown in  FIG. 2 ) extending through the handle assembly  102 ) within the receptacle  112 . 
         [0043]    With the tray  302  secured to the head assembly mount  200 , the torque transfer assemblies  306  are connected to the drive shafts  210 . Specifically, the caps  348  are connected to the tips  212  of the respective drive shafts  210  such that the bottom walls  354  of the caps  348  are seated on the retaining rings  214  and such that the inner surfaces  362  of the ports  358  frictionally engage the roughened surfaces  216 . After the caps  348  are connected to the drive shafts  210 , the pins  352  are seated on the biasing members  350  within the caps  348  such that the hollow bodies  368  of the pins  352  receive the biasing members  350  and such that the guides  370  of the pins  352  are inserted into the channels  360  of the caps  348 . 
         [0044]    To assemble the cutter frame assembly  400 , the biasing element  404  is seated on the lower cutter frame  402  about the spring seat  422  of the base  410 . The cutter holders  406  are then connected to the lower cutter frame  402  such that the pivot arms  428  of the cutter holders  406  are inserted into the biasing element  404  and such that the sloped inner walls  416  of each holder support  408  are received within the gaps  442  of the respective cutter holder  406  (i.e., the prongs  430  are positioned below the lower surfaces  420  of the sloped inner walls  416 , and the bowl  426  is positioned atop the upper surfaces  418  of the sloped inner walls  416 ). With the cutter holders  406  mounted on the lower cutter frame  402 , the fastener  450  is inserted through the bore  424  of the base  410 , through the biasing element  404 , and into the central boss  454  of the upper cutter frame  444  to fasten the lower cutter frame  402  to the upper cutter frame  444 . 
         [0045]    The inner cutters  472  and the inner cutter stems  474  are then inserted into the cutter holders  406  (i.e., each inner cutter  472  is inserted into the respective cutter holder  406  with the inner cutter stem  474  suitably connected to the bottom surface  476  thereof). With the inner cutters  472  and inner cutter stems  474  inserted into the cutter holders  406 , the outer cutters  464  are inserted into the cutter cases  448  and are seated against the inner flanges  486 , and the buffer rings  470  are inserted into the cutter cases  448  against the outer cutters  464 . Specifically, the outer cutters  464  are inserted into the cutter cases  448  such that the skin contacting surfaces  468  of the outer cutters  464  are exposed though the cutter cases  448  and are substantially parallel to the respective upper skin contacting surfaces  492  of the cutter cases  448 . 
         [0046]    With the outer cutters  464  positioned within the cutter cases  448 , the cutter cases  448  are then fastened to the cutter holders  406  through the cutter ports  452  and about the inner cutters  472 . Specifically, the alignment fingers  493  of the cutter cases  448  are aligned with the protrusions  462  of the upper cutter frame  444 , and the locking members  490  of the cutter cases  448  are inserted into the tracks  432  of the cutter holders  406  via the inlet sections  436  of the tracks  432 . The cutter cases  448  are then rotated such that the locking members  490  slide across the respective runner sections  440  of the tracks  432  and are secured within the cove sections  438  of the tracks  432 . When the cutter cases  448  are secured to the cutter holders  406 , the alignment finger  493  is aligned with the dimple  460  of the upper cutter frame  444 . 
         [0047]    After the hair retention assembly  300  is mounted on the handle assembly  102  and the cutter frame assembly  400  is assembled, the cutter frame assembly  400  is hingedly connected to the hair retention assembly  300  at the hinge  456 , and the locking tab  458  of the upper cutter frame  444  engages the lock  337  of the tray  302 . Moreover, when the cutter frame assembly  400  is mounted on the hair retention assembly  300 , the pins  352  of the torque transfer assembly  306  are inserted through the bowls  426  of the cutter holders  406  to engage the inner cutter stems  474  (i.e., the tips  366  of the pins  352  engage the sockets  478  of the inner cutter stems  474 ) to facilitate operatively connecting each of the inner cutters  472  to a respective one of the drive shafts  210  for conjoint rotation therewith (i.e., to facilitate transferring torque from the drive shafts  210  to the inner cutters  472  when the rotary shaver  100  is operating). 
         [0048]    During an exemplary operation of the rotary shaver  100 , a user grasps the handle assembly  102  and glides the outer cutters  464  over the skin such that hairs from the skin are directed into the slits  466  of the outer cutters  464 , wherein the hairs are cut via the rotating inner cutters  472  and are stored in the hair pocket  314  of the hair retention assembly  300  for subsequent disposal. As the outer cutters  464  glide over contours of the skin (e.g., the contours of the user&#39;s face), the outer cutters  464  and the cutter cases  448  are permitted to float up and down via the biasing element  404  to facilitate maintaining the outer cutters  464  in contact with the skin. Specifically, when rounding a contour, the pivot arms  428  of the cutter holders  406  are permitted to compress the biasing element  404  such that the cutter holders  406  slide along the respective arms  412  (i.e., the prongs  430  slide underneath the lower surfaces  420  of the sloped inner walls  416 , and the bowl  426  slides atop the upper surfaces  418  of the sloped inner walls  416 ). Optionally, in an alternative embodiment, the outer cutters  464  may be permitted to float within, and relative to, the cutter cases  448 . 
         [0049]    To further facilitate maintaining the skin contacting surfaces  468  of the outer cutters  464  in contact with the skin when rounding contours of the skin, the head assembly  104  is permitted to float up and down within the upper receptacle  112  and/or to pivot relative to the handle housing  110  within the upper receptacle  112  in any direction about the entire circumference of the shaver head assembly  104  (i.e., pivot in 360 degrees about the longitudinal axis Y) via the spring  372  due in part to the space left between the feet  328  of the tray  302  and the head assembly mount  200 . Moreover, the spring  372  biases the head assembly  104  generally longitudinally away from the handle housing  110  such that the head assembly  104  is movable longitudinally toward the handle housing  110  against the bias of the spring  372  in response to pressure applied to the head assembly  104  by a user of the shaver  100 . 
         [0050]    Additionally, because the spring  372  of the pivot assembly  308  is positioned in the upper receptacle  112  (i.e., exterior of the hair pocket  314 ) in the illustrated embodiment, rather than in the hair pocket  314 , an accumulation of hair within the hair pocket  314  does not limit the pivot range of the head assembly  104 . Additionally, when either the head assembly  104  and/or the cutter cases  448  float and/or pivot, the caps  348  of the torque transfer assemblies  306  maintain a fixed position relative to the drive shafts  210  because the caps  348  are seated atop the retaining rings  214 . The pins  352  are also permitted to float and pivot within the caps  348  via compression of the biasing members  350 , which facilitates maintaining a driving engagement between the pins  352  and the inner cutter stems  474  despite the floating and/or pivoting. 
         [0051]    Because the first annular segments  496  of the peripheral skin contacting surfaces  494  are sloped at a lesser angle than the second annular segments  497  of the peripheral skin contacting surfaces  494 , the transition of the skin from the upper cutter frame  444  to the upper skin contacting surfaces  492  of the cutter cases  448  is gradual to facilitate enabling the skin to slide smoothly from the upper cutter frame  444  up to, and subsequently down from, the upper skin contacting surfaces  492 . Moreover, because the width W 1  of the first annular segments  498  of the upper skin contacting surfaces  492  is greater than the width W 2  of the second annular segments  499  of the upper skin contacting surfaces  492  and because the cutter cases  448  are arranged on the upper cutter frame  444  such that the second annular segments  499  of the upper skin contacting surfaces  492  face one another (i.e., are oriented toward the center of the head assembly  104 ), the combined surface area of the upper skin contacting surfaces  492  of the cutter cases  448  is greater proximate a central region of the upper cutter frame  444  to facilitate enabling a smoother transition of the skin across the head assembly  104  from any given cutter case  448  to the adjacent cutter cases  448 . 
         [0052]    Additionally, after a shaving operation, the user may empty the hair stored in the hair pocket  314  by unlatching the locking tab  458  from the lock  337  via the lock release button  114  and swinging the cutter frame assembly  400  away from the hair retention assembly  300  via the hinge  456 . However, if the user desires to clean the cutters  446  without accessing the hair pocket  314 , the user may grasp the cutter cases  448  (i.e., via the ridges  495 ), apply a downward force to the cutter cases  448 , and rotate the cutter cases  448  relative to the cutter holders  406  such that the locking members  490  slide downward within the cove sections  438 , back across the runner sections  440 , and upward through the inlet sections  436 , thereby releasing the cutter cases  448  from the cutter holders  406  to access the cutters  446  (i.e., each of the cutter cases  448  is individually releasable from the head assembly  104 ). When one of the cutter cases  448  is removed from the respective cutter holder  406 , the outer cutter  446 , the inner cutter  472 , and/or the inner cutter stem  474  are removable from within the cutter case  448  to facilitate cleaning the cutters  446 . In one embodiment, when resecuring the cutter cases  448  to the cutter holders  406 , the user may align the alignment finger  493  of the cutter case  448  with the protrusion  462  of the upper cutter frame  444  to insert the locking members  490  into the inlet sections  436  and may subsequently rotate the cutter case  448  toward the dimple  460  to engage the locking members  490  within the cove sections  438 , thereby securing the cutter case  448  to the cutter holder  406 . 
         [0053]    When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the”, and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including”, and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
         [0054]    As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.