Abstract:
In one illustrative embodiment, there is provided a boot sole system for guiding a fm, the system comprising: at least one toe sole body connectable to the fin and comprising first and second stop surfaces; a posterior sole body comprising third and fourth stop surfaces; and a transverse hinge for hingedly connecting the at least one toe sole body to the posterior sole body to permit longitudinal deflection of the at least one toe sole body relative to the posterior sole body in a first deflection direction and in a second deflection direction opposite the first deflection direction. The first, second, third, and fourth stop surfaces are positioned to restrict longitudinal deflection of the at least one toe sole body relative to the posterior sole body in the first deflection direction and in the second deflection direction. Fins are also disclosed.

Description:
BACKGROUND 
       [0001]    1. Field 
         [0002]    The invention relates generally to boot soles and fins for boot soles. 
         [0003]    2. Related Art 
         [0004]    A user can couple a known flipper to each foot of the user. These known flippers have fins, and when the user kicks in water, for example, the fins can facilitate generating propulsion in the water. 
         [0005]    Many known flippers have foot pockets for receiving a foot of a user, but these foot pockets are generally integral to the fin and available only in a small number of standard sizes because, for example, manufacturing and distribution costs of entire flippers with a large variety of foot sizes and shapes would be prohibitive. Therefore, when a user selects a flipper, a user must also select a single foot pocket size of the flipper, often from among a small number of available sizes. Therefore, these foot pockets often do not comfortably fit a foot of a user, and space between the foot and an inside wall of the foot pocket can receive water, disadvantageously adding to drag of the flipper in water and limiting the control of the user over the flipper. Other known flippers include alternatives to foot pockets, but such known alternatives may still require a user to choose from small number of standard sizes because, for example, of potentially high manufacturing and distribution costs for a large variety of foot sizes. 
       SUMMARY 
       [0006]    According to one illustrative embodiment, there is provided a boot sole system for guiding a fin, the system comprising: at least one toe sole body connectable to the fin and comprising first and second stop surfaces; a posterior sole body comprising third and fourth stop surfaces; and a transverse hinge for hingedly connecting the at least one toe sole body to the posterior sole body to permit longitudinal deflection of the at least one toe sole body relative to the posterior sole body in a first deflection direction and in a second deflection direction opposite the first deflection direction. The first, second, third, and fourth stop surfaces are positioned such that when the transverse hinge connects the at least one toe sole body to the posterior sole body: the first and third stop surfaces abut each other in response to longitudinal deflection of the at least one toe sole body relative to the posterior sole body in the first deflection direction to restrict longitudinal deflection of the at least one toe sole body relative to the posterior sole body in the first deflection direction; and the second and fourth stop surfaces abut each other in response to longitudinal deflection of the at least one toe sole body relative to the posterior sole body in the second deflection direction to restrict longitudinal deflection of the at least one toe sole body relative to the posterior sole body in the second deflection direction. 
         [0007]    According to another illustrative embodiment, there is provided a fin comprising a toe sole body hingedly connectable to a posterior sole body of a boot, wherein the toe sole body comprises first and second stop surfaces, and wherein: the first stop surface is positioned to abut a third stop surface on the posterior sole body in response to longitudinal deflection of the toe sole body relative to the posterior sole body in a first deflection direction, when the toe sole body is connected to the posterior sole body, to restrict longitudinal deflection of the toe sole body relative to the posterior sole body in the first deflection direction; and the second stop surface is positioned to abut a fourth stop surface on the posterior sole body in response to longitudinal deflection of the toe sole body relative to the posterior sole body in a second deflection direction opposite the first deflection direction, when the toe sole body is connected to the posterior sole body, to restrict longitudinal deflection of the toe sole body relative to the posterior sole body in the second deflection direction. 
         [0008]    Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is an exploded bottom perspective view of a boot system according to one illustrative embodiment; 
           [0010]      FIG. 2  is a bottom perspective view of a posterior sole body of the boot system of  FIG. 1 ; 
           [0011]      FIG. 3  is a bottom perspective view of a toe sole body of the boot system of  FIG. 1 ; 
           [0012]      FIG. 4  is an elevation view of the posterior sole body of  FIG. 2  and the toe sole body of  FIG. 3  illustrating a maximum longitudinal deflection of the toe sole body of  FIG. 3  relative to the posterior sole body of  FIG. 2  in a first deflection direction; 
           [0013]      FIG. 5  is an elevation view of the posterior sole body of  FIG. 2  and the toe sole body of  FIG. 3  illustrating a maximum longitudinal deflection of the toe sole body of  FIG. 3  relative to the posterior sole body of  FIG. 2  in a second deflection direction; 
           [0014]      FIG. 6  is a bottom view of the posterior sole body of  FIG. 2  and the toe sole body of  FIG. 3 ; 
           [0015]      FIG. 7  is a bottom view of a boot system according to another illustrative embodiment; 
           [0016]      FIG. 8  is an elevation view of the boot system of  FIG. 7 ; 
           [0017]      FIG. 9  is a bottom view of a boot system according to another illustrative embodiment; 
           [0018]      FIG. 10  is an elevation view of the boot system of  FIG. 9 ; 
           [0019]      FIG. 11  is an exploded bottom view of a frame of the boot system of  FIG. 1  and fin elements of a fin; 
           [0020]      FIG. 12  is a bottom view of the frame and the fin of  FIG. 11 ; 
           [0021]      FIG. 13  is a bottom view of the frame of  FIG. 11  when folded along a longitudinal hinge of the frame of  FIG. 11 ; 
           [0022]      FIG. 14  is an elevation view of the frame and the fin of  FIG. 11 ; 
           [0023]      FIG. 15  is a cross-sectional view of the boot system of  FIG. 1  and the fin of  FIG. 11 ; 
           [0024]      FIG. 16  is a bottom view of a frame and a fin according to another illustrative embodiment; 
           [0025]      FIG. 17  is an exploded bottom view of a boot sole system according to another illustrative embodiment; 
           [0026]      FIG. 18  is an assembled bottom view of the boot sole system of  FIG. 17 ; 
           [0027]      FIG. 19  is a top perspective view of a boot system according to another illustrative embodiment; 
           [0028]      FIG. 20  is a bottom perspective view of a toe sole body of the boot system of  FIG. 19 ; 
           [0029]      FIG. 21  is a top perspective view of a frame of the boot system of  FIG. 19 ; 
           [0030]      FIG. 22  is a top perspective view of a boot system according to another illustrative embodiment; 
           [0031]      FIG. 23  is a partial cross-sectional view of the boot system of  FIG. 22 , taken along the line XXIII-XXIII in  FIG. 22 ; and 
           [0032]      FIG. 24  is a top perspective view of a boot system according to another illustrative embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    Referring to  FIG. 1 , a boot system according to one illustrative embodiment is shown generally at  100 . The boot system  100  includes a boot  102 , a posterior sole body  104 , a toe sole body  106 , and a frame (or “Y-frame”)  108 . 
         [0034]    When a user wearing the boot system  100  walks on a surface, a bottom side shown generally at  110  generally faces downward and therefore generally contacts the surface. In general, a “bottom” side herein refers to a side that faces downward and generally contacts a surface when a user walks on the surface. However, when swimming or diving in water, a user generally faces downward, and therefore a “bottom” side herein refers to a side that generally faces upward when in use during swimming or diving in water. A drawing of a “bottom view” herein generally refers to a view of such a “bottom” side, and therefore a “bottom view” herein generally refers to a view from above when in use in water. 
         [0035]    The boot  102  includes a boot sole  112  on the bottom side  110  of the boot  102 , and as described further below, the boot sole  112  in various embodiments may be bonded to the posterior sole body  104  and to the toe sole body  106  to form an integral boot sole including the posterior sole body  104  and the toe sole body  106 . 
         [0036]    Referring to  FIG. 2 , the posterior sole body  104  extends between a heel end shown generally at  114  and a midsole end shown generally at  116  and opposite the heel end  114 . The posterior sole body  104  also has a bottom side shown generally at  118  and a top side shown generally at  120 . As indicated above, the bottom side  118  generally faces downward and generally contacts a surface when a user walks on the surface, but the bottom side  118  generally faces upward when in use during swimming or diving in water for example. The posterior sole body  104  is relatively rigid, and in various embodiments may include one of, or a combination of more than one of, carbon fibre, relatively rigid thermoplastic material, and metal. The posterior sole body  104  on the top side  120  may define a mesh grid pattern (not shown) to facilitate adhesion to and bonding with the bottom side  110  of the boot sole  112  (shown in  FIG. 1 ). 
         [0037]    At the midsole end  116 , the posterior sole body  104  includes generally cylindrical pivot holders  122  and  124 . The pivot holder  122  defines axial through-openings  126  and  128  and the pivot holder  124  defines axial through-openings  130  and  132 . The through-openings  126 ,  128 ,  130 , and  132  are sized and aligned along a generally transverse axis  134  to receive a pivot  136  (shown in  FIG. 1 ) along the generally transverse axis  134 . Also at the midsole end  116 , the posterior sole body  104  defines stop surfaces  138 ,  140 ,  142 , and  144  on the bottom side  118  and stop surfaces  146  and  148  on the top side  120 . The stop surfaces  138 ,  140 ,  142 , and  144  are generally coplanar in a plane extending from the generally transverse axis  134  towards the bottom side  118 , and the stop surfaces  146  and  148  are generally coplanar in a plane extending from the generally transverse axis  134  towards the top side  120 . 
         [0038]    The pivot holder  122  defines an opening shown generally at  150  at the midsole end  116 , and the pivot holder  124  defines an opening shown generally at  152  at the midsole end  116 . The openings  150  and  152  may receive respective projections on the toe sole body  106  (shown in  FIG. 1 ) for hingedly connecting the toe sole body  106  to the posterior sole body  104  as described further below. 
         [0039]    The posterior sole body  104  includes projections  154 ,  156 ,  158 ,  160 ,  162 ,  164 ,  166 , and  168  projecting towards the bottom side  118 , with a generally transverse gap  170  between the projections  154 ,  156 ,  158 , and  160 , a generally transverse gap  172  between the projections  158 ,  160 ,  162 , and  164 , and a generally transverse gap  174  between the projections  162 ,  164 ,  166 , and  168 . The generally transverse gaps  170 ,  172 , and  174  are spaced apart from each other longitudinally, namely in a direction extending from the heel end  114  to the midsole end  116 . 
         [0040]    Referring to  FIG. 3 , the toe sole body  106  extends between a midsole end shown generally at  176  and a toe end shown generally at  178  and opposite the midsole end  176 . The toe sole body  106  also has a bottom side shown generally at  180  and a top side shown generally at  182 . As indicated above, the bottom side  180  generally faces downward and generally contacts a surface when a user walks on the surface, but the bottom side  180  generally faces upward when in use during swimming or diving in water for example. The toe sole body  106  is relatively rigid, and in various embodiments may include one of, or a combination of more than one of, carbon fibre, relatively rigid thermoplastic material, and metal. The toe sole body  106  on the top side  182  may define a mesh grid pattern (not shown) to facilitate adhesion to and bonding with the bottom side  110  of the boot sole  112  (shown in  FIG. 1 ). 
         [0041]    On the bottom side  180  and towards the toe end  178 , the toe sole body  106  defines a generally planar abutment surface  184  and generally curved abutment surfaces  186  and  188  (shown in  FIG. 1 ) extending away from the generally planar abutment surface  184  towards the bottom side  180 . The abutment surfaces  184 ,  186 , and  188  abut corresponding surfaces of the frame  108  and define a receptacle shown generally at  190  for receiving a portion of the frame  108  as described further below. 
         [0042]    Facing the midsole end  176 , the toe sole body  106  defines a generally semi-cylindrical recess shown generally at  192  and a generally semi-cylindrical recess shown generally at  194 . A projection  196  projects into the recess  192  towards the midsole end  176 , and a projection  198  projects into the recess  194  towards the midsole end  176 . The projection  196  defines a transverse through-opening  200 , and the projection  198  defines a transverse through-opening  202 . The through-openings  200  and  202  are aligned along a generally transverse axis  204  and are sized to receive the pivot  136  (shown in  FIG. 1 ). Also at the midsole end  176 , the toe sole body  106  defines stop surfaces  206  and  208  on the bottom side  180  and stop surfaces  210  and  212  on the top side  182 . The stop surfaces  206  and  208  are generally coplanar in a plane extending from the generally transverse axis  204  towards the bottom side  180 , and the stop surfaces  210  and  212  are generally coplanar in a plane extending from the generally transverse axis  204  towards the top side  182 . 
         [0043]    Referring to  FIGS. 1 ,  2 , and  3 , the recesses  192  and  194  are sized to receive respective portions of the pivot holders  122  and  124  respectively, and the projections  196  and  198  are sized to be received in the openings  150  and  152  respectively when the recesses  192  and  194  receive the respective portions of the pivot holders  122  and  124  such that the generally transverse axes  134  and  204  coincide to permit the through-openings  200  and  202  to receive the pivot  136  along the generally transverse axis  134 . The pivot  136  thus functions as a transverse hinge for hingedly connecting the midsole end  176  of the toe sole body  106  to the midsole end  116  of the posterior sole body  104 . Further, the stop surfaces  138 ,  140 ,  142 ,  144 ,  146 ,  148 ,  206 ,  208 ,  210 , and  212  are positioned such that when the recesses  192  and  194  receive the respective portions of the pivot holders  122  and  124  and when the through-openings  126 ,  128 ,  130 ,  132 ,  200 , and  202  receive the pivot  136 , the toe sole body  106  may pivot about the pivot  136  to deflect longitudinally relative to the posterior sole body  104  in a first deflection direction  214  (shown in  FIGS. 4 and 5 ) and in a second deflection direction  216  opposite the first deflection direction  214 . 
         [0044]    Referring to  FIGS. 2 ,  3 , and  4 , in response to longitudinal deflection of the toe sole body  106  relative to the posterior sole body  104  in the first deflection direction  214 , the stop surfaces  138  and  140  abut the stop surface  206  and the stop surfaces  142  and  144  abut the stop surface  208  to restrict longitudinal deflection of the toe sole body  106  relative to the posterior sole body  104  in the first deflection direction  214 . Also, referring to  FIGS. 2 ,  3 , and  5 , in response to longitudinal deflection of the toe sole body  106  relative to the posterior sole body  104  in the second deflection direction  216 , the stop surfaces  146  and  148  abut the stop surfaces  210  and  212  respectively to restrict longitudinal deflection of the toe sole body  106  relative to the posterior sole body  104  in the second deflection direction  216 . The stop surfaces  138 ,  140 ,  142 ,  144 ,  146 ,  148 ,  206 ,  208 ,  210 , and  212  thus define a maximum longitudinal deflection range  218  between a maximum longitudinal deflection of the toe sole body  106  relative to the posterior sole body  104  in the first deflection direction  214  (shown in  FIG. 4 ) and a maximum longitudinal deflection of the toe sole body  106  relative to the posterior sole body  104  in the second deflection direction  216  (shown in  FIG. 5 ). 
         [0045]    Referring back to  FIG. 3 , on the bottom side  180  and towards the toe end  178 , the toe sole body  106  defines laterally opposite receptacles  220  and  222  for receiving and retaining respective portions of a resilient body, such as an elastomeric body  224  shown in  FIG. 6  for example. The laterally opposite receptacles  220  and  222  may more generally be referred to as resilient body connectors. Referring to  FIGS. 3 and 6 , the receptacles  220  and  222  include respective relatively wide portions for receiving relatively wide end portions of the elastomeric body  224 , and the receptacles  220  and  222  include respective relatively narrow portions adjacent the respective relatively wide portions for retaining the relatively wide end portions of the elastomeric body  224 . Further, the receptacles  220  and  222  are open at respective opposite sides of the toe sole body  106  to receive respective end portions  226  and  228  of the elastomeric body  224  as shown in  FIG. 6 . 
         [0046]    Referring to  FIG. 6 , a middle portion shown generally at  230  of the elastomeric body  224  is received in the generally transverse gap  172 , and may alternatively be received in the generally transverse gap  170  or in the generally transverse gap  174 . Because the generally transverse gaps  170 ,  172 , and  174  are spaced apart from each other longitudinally, moving the middle portion  230  of the elastomeric body  224  to different ones of the generally transverse gaps  170 ,  172 , and  174  may vary a tension of the elastomeric body  224 , and varying the tension of the elastomeric body  224  may adjust a tendency of the toe sole body  106  to deflect longitudinally relative to the posterior sole body  104 . Moving the middle portion  230  of the elastomeric body  224  to different ones of the generally transverse gaps  170 ,  172 , and  174  may thus vary a flexibility of a boot sole including the posterior sole body  104  and the toe sole body  106 , which may be desirable in some swimming or diving applications for example. Also, flexibility of such a boot sole may be varied by varying a material of the elastomeric body  224 . The generally transverse gaps  170 ,  172 , and  174  may more generally be referred to as resilient body connectors defined by the posterior sole body  104 . 
         [0047]    Referring to  FIGS. 7 and 8 , a boot system according to another illustrative embodiment includes a boot  232  including a boot sole integrally formed with the posterior sole body  104  and the toe sole body  106 . An elastomeric body  234  extends from the sole body  106  to the posterior sole body  104  as shown in  FIG. 6 , except that the elastomeric body  234  includes a heel strap  236  sized to extend laterally around a heel region of the boot  232  and attach to a heel strap attachment  238  near a heel end of the boot  232  for attaching the heel strap  236  to the boot  232 . Attaching the heel strap  236  to the heel strap attachment  238  may vary a tension of the elastomeric body  234  to vary a flexibility of the boot sole as described above. In some embodiments, the heel strap attachment  238  may permit the heel strap  236  to be attached to the boot  232  in a plurality of positions, and attaching the heel strap  236  to the boot  232  in different ones of the plurality of positions may vary the tension of the elastomeric body  234  to vary the flexibility of the boot sole as described above. 
         [0048]    Referring to  FIGS. 9 and 10 , a boot system according to another illustrative embodiment includes a boot  240  including a boot sole integrally formed with the posterior sole body  104  and the toe sole body  106 . An elastomeric body  242  extends from the sole body  106  to the posterior sole body  104  as shown in  FIG. 6 , except that the elastomeric body  242  includes a heel strap  244  sized to extend under a heel region of the boot  240  on a bottom side of the boot  240  and attach to a heel strap attachment  246  near a heel end of the boot  240  for attaching the heel strap  244  to the boot  240 . Attaching the heel strap  244  to the heel strap attachment  246  may vary a tension of the elastomeric body  242  to vary a flexibility of the boot sole as described above. In some embodiments, the heel strap attachment  246  may permit the heel strap  244  to be attached to the boot  240  in a plurality of positions, and attaching the heel strap  244  to the boot  240  in different ones of the plurality of positions may vary the tension of the elastomeric body  242  to vary the flexibility of the boot sole as described above. 
         [0049]    Referring to  FIG. 11 , the frame  108  includes first and second laterally opposite frame elements  248  and  250  and a longitudinal hinge  252  hingedly connecting the first and second laterally opposite frame elements  248  and  250 . The first laterally opposite frame element  248  defines through-openings  252  and  254  for connecting the first laterally opposite frame element  248  to a fin element  256 , and the second laterally opposite frame element  250  defines through-openings  258  and  260  for connecting the second laterally opposite frame element  250  to a fin element  262 . The fin element  256  includes a hinge element  264  defining through-openings  266  and  268 ; a fastener (not shown) may pass through the through-openings  252  and  266  and another fastener (not shown) may pass through the through-openings  254  and  268  to connect the first laterally opposite frame element  248  to the fin element  256 . Also, the fin element  262  includes a hinge element  270  defining through-openings  272  and  274 ; a fastener (not shown) may pass through the through-openings  258  and  272  and another fastener (not shown) may pass through the through-openings  260  and  274  to connect the second laterally opposite frame element  250  to the fin element  262 . However, alternative embodiments may include different fins which may be attached to the frame  108  in different ways. 
         [0050]    Referring to  FIG. 12 , when the first laterally opposite frame element  248  is connected to the fin element  256  and the second laterally opposite frame element  250  is connected to the fin element  262 , the fin elements  256  and  262  form a fin shown generally at  276 . The fin  276  is thus connectable to the frame  108 . In alternative embodiments, the fin may be permanently connected to the frame, but nevertheless such a fin may be referred to as “connectable” to the frame. In general, “connectable” herein may refer to a permanent connection or to a selectable connection. 
         [0051]    The fin  276  has a proximal end shown generally at  278  and a distal end shown generally at  280  and opposite the proximal end  278 . Further, the hinge element  264  has a hinge axis  282  and the hinge element  270  has a hinge axis  284 . The hinge axis  282  extends away from a central longitudinal axis  286  of the fin  276  and towards the distal end  280  at an acute angle  288 , and the hinge axis  284  extends away from the central longitudinal axis  286  of the fin  276  and towards the distal end  280  at an acute angle  290 . The fin  276  may therefore spread apart in response to lateral deflection of the fin  276  relative to the frame  108  similarly to various fins described and illustrated in U.S. patent application Ser. No. 13/639,446, originally published as WO 2011/123950 A1. The entire contents of U.S. patent application Ser. No. 13/639,446 are incorporated by reference herein. As indicated above, alternative embodiments may include different fins which may include fins similar to those described in and illustrated in WO 2011/123950 A1 or still other fins. 
         [0052]    Referring to  FIGS. 11 ,  12 , and  13 , the frame  108  includes a connector  292  for connecting the frame  108  to the pivot  136  (shown in  FIGS. 1 and 4  to  6 ). The connector  292  includes a generally planar flange  294  fastened to the first laterally opposite frame element  248  but not fastened to the second laterally opposite frame element  250 . Therefore, when the first and second laterally opposite frame elements  248  and  250  are extended apart from each other around the longitudinal hinge  252  (as shown in  FIGS. 11 and 12 ), the second laterally opposite frame element  250  abuts the generally planar flange  294  and the generally planar flange  294  prevents further rotation of the second laterally opposite frame element  250  around the longitudinal hinge  252 , thus maintaining the first and second laterally opposite frame elements  248  and  250  generally coplanar. However, the second laterally opposite frame element  250  may be pivoted around the longitudinal hinge  252  away from the generally planar flange  294  and towards the first laterally opposite frame element  248 , effectively permitting the frame  108  to be folded around the longitudinal hinge  252 . Folding the frame  108  around the longitudinal hinge  252  may reduce space consumed by the frame  108 , and reduced space may be desirable in some applications such as storing or transporting the frame  108  for example. 
         [0053]    Referring to  FIGS. 14 and 15 , the connector  292  defines a receptacle shown generally at  296  and sized to receive a portion of the pivot  136  to connect the frame  108  to the pivot  136 . As shown in  FIG. 1 , the pivot  136  includes a threaded end shown generally at  298 , and the through-opening  126  defines complementary threads (not shown) to hold the pivot  136  in the through-openings  126 ,  128 ,  130 ,  132 ,  200 , and  202  (shown in  FIGS. 2 and 3 ) when the generally transverse axes  134  and  204  coincide (shown in  FIGS. 2 and 3 ). The pivot  136  is thus removable from the posterior sole body  104  and from the toe sole body  106  by removing the threaded end  298  from the complementary threads of the through-opening  126 . In alternative embodiments, the pivot  136  may be held by a friction fit instead of by threads. When the pivot  136  thus removed, the frame  108  may be positioned with a portion of the connector  292  between the pivot holders  122  and  124  (shown in  FIG. 2 ), and the receptacle  296  is configured to receive the pivot  136  when the frame  108  is thus positioned, as shown in  FIG. 15 . The receptacle  296  defines a retaining surface  300  in the receptacle  296  that abuts the pivot  136  when the receptacle  296  receives the pivot  136  as shown in  FIG. 15  to retain the connector  292  and thus the frame  108  to the pivot  136 . The frame  108  is thus removably connectable to the posterior sole body  104  at the pivot  136 . 
         [0054]    As indicated above, the generally planar flange  294  prevents rotation of the second laterally opposite frame element  250  around the longitudinal hinge  252  beyond the generally planar flange  294 . Further, in  FIG. 15 , the first and second laterally opposite frame elements  248  and  250  abut the generally planar abutment surface  184 , and the generally planar abutment surface  184  thus prevents rotation of the second laterally opposite frame element  250  around the longitudinal hinge  252  away from the generally planar flange  294 . Therefore, as shown in  FIG. 15 , when the first and second laterally opposite frame elements  248  and  250  abut the generally planar abutment surface  184 , the generally planar abutment surface  184  and the generally planar flange  294  maintain the first and second laterally opposite frame elements  248  and  250  generally coplanar. 
         [0055]    The connector  292  also defines a stop  302  having a stop surface  304 . Referring to  FIG. 15 , in response to longitudinal deflection of the frame  108  relative to the posterior sole body  104  in the first deflection direction  214 , the stop surface  304  abuts a stop surface  306  (also shown in  FIG. 2 ) on the posterior sole body  104  to restrict longitudinal deflection of the frame  108  relative to the posterior sole body  104  in the first deflection direction  214 . 
         [0056]    Therefore, both the toe sole body  106  and the frame  108  are connected to the pivot  136  and may pivot about the pivot  136  for longitudinal deflection relative to the posterior sole body  104  in the first deflection direction  214  and in the second deflection direction  216 . 
         [0057]    In operation, when a foot of a user (not shown) is received in the boot  102 , the pivot  136  may be proximate metatarsophalangeal joints (or simply toe joints) of the user. In other words, one or both of the toe sole body  106  and the frame  108  may deflect longitudinally with the toes of the user. Therefore, the frame  108  may also be referred to as a “toe sole body” and the toe sole body  106  and the frame  108  may collectively be referred to as “at least one toe sole body” connectable to a fin (the fin  276  shown in  FIG. 12  in the embodiment shown) because at least one of the at least one toe sole body (the frame  108  in the embodiment shown) is connectable to the fin. 
         [0058]    Although the pivot  136  is referred to herein as a transverse hinge, the pivot  136  (and other transverse hinges described herein) do not necessarily extend perpendicular to any longitudinal axis. Rather, in the embodiment shown in  FIG. 15  for example, the pivot  136  may extend under metatarsophalangeal joints of a user, which may follow a curve that is not perpendicular to any longitudinal axis. More generally, transverse hinges described herein may extend transversely at various angles that may be desired in various embodiments but that are not necessarily perpendicular to any longitudinal axis. Although the transverse hinge in the embodiment shown is the pivot  136 , transverse hinges in other embodiments may include other hinges, such as thermoplastic hinges for example. 
         [0059]    Referring to  FIGS. 1 and 15 , because the first and second laterally opposite frame elements  248  and  250  abut the generally planar abutment surface  184 , and because the generally planar abutment surface  184  is on the toe sole body  106  that may be below (or “inferior to”) toes of a user as shown in  FIG. 15 , the first and second laterally opposite frame elements  248  and  250  may extend laterally from below (or “inferior to”) toes of the user rather than from in front of (or “anterior to”) the toes of the user. In such embodiments, an overall length of the boot system  100  and the fin  276  (shown in  FIG. 12 ) may be shorter when compared to some other fins that do not include structure below (or “inferior to”) toes of a user and instead include more structure and spacing in front of (or “anterior to”) the toes of the user. Such reduced overall length may be advantageous in some applications where compactness of a fin may be desirable. Further, reduced overall length may improve a mechanical advantage of a user&#39;s leg and reduce strain on the user&#39;s leg because when the fin is closer to the user&#39;s hip, knee, ankle, and toe joints, less force is required to move the fin by a given angle about such joints. 
         [0060]    In the embodiment shown in  FIG. 15 , the toe sole body  106  and the frame  108  do not necessarily move together, and for example when a user wearing the boot  102  kicks downward (which would be upward in  FIG. 15  if the user is facing down while swimming or diving), then the frame  108  may be deflected longitudinally relative to the posterior sole body  104  in the first deflection direction  214  without necessarily longitudinally deflecting the toe sole body  106  in the first deflection direction  214  to the same extent as the frame  108  or at all. However, in alternative embodiments such as those shown in  FIGS. 17 to 24  for example, the frame may be fastened to the toe sole body such that the frame and the toe sole body move together, generally with longitudinal deflection relative to the posterior sole body in substantially similar angles. Also, although the toe sole body  106  and the frame  108  are separate bodies in the embodiment shown, alternative embodiments may include a single toe sole body connectable to a fin and hingedly connectable to a posterior sole body. 
         [0061]    Further, the at least one toe sole body (the toe sole body  106  and the frame  108  in the embodiment shown) collectively include at least one stop surface (one or more of the stop surfaces  206 ,  208 , and  304  in the embodiment shown) to restrict longitudinal deflection of the toe sole body  106  relative to the posterior sole body  104  in the first deflection direction  214  and at least one stop surface (one or more of the stop surfaces  210  and  212  in the embodiment shown) to restrict longitudinal deflection of the toe sole body  106  relative to the posterior sole body  104  in the second deflection direction  216 , and thus the at least one toe sole body in the embodiment shown includes a stop surface to restrict longitudinal deflection of the toe sole body  106  relative to the posterior sole body  104  in the first deflection direction  214  and a stop surface to restrict longitudinal deflection of the toe sole body  106  relative to the posterior sole body  104  in the second deflection direction  216 . In alternative embodiments, one or more of at least one toe sole body may include a stop surface to restrict longitudinal deflection relative to a posterior sole body in a first deflection direction and a stop surface to restrict longitudinal deflection relative to the posterior sole body in a second deflection direction opposite the first deflection direction, and such stop surfaces may be on the same toe sole body or on different toe sole bodies in various embodiments. 
         [0062]    As shown in  FIG. 5 , stop surfaces in the embodiment shown restrict longitudinal deflection of the of the toe sole body  106  relative to the posterior sole body  104  to a maximum longitudinal deflection range  218 . In some embodiments, the maximum longitudinal deflection range  218  may be within a normal range for bending of metatarsophalangeal joints. In some embodiments, the maximum longitudinal deflection range  218  may range from a position where toes are fully extended forward (or anterior) to a maximum normal superior (that is, towards the head of the user) bending. For example, a maximum normal superior bending of metatarsophalangeal joints may be about 30° to about 80°, and therefore in some embodiments, the maximum longitudinal deflection range  218  may range from a position where toes are fully extended forward (or anterior) to, for example, about 30°, about 35°, about 40°, about 45°, about 50°, about 55°, about 60°, about 65°, about 70°, about 75°, or about 80° superior (that is, towards the head of the user) to the position where toes are fully extended. 
         [0063]    In general, the pivot  136  and other transverse hinges such as those described herein may in some embodiments improve a connection between a user&#39;s foot and a fin attached to the user&#39;s foot when compared to other boot bindings systems. For example, a user of the boot system  100  may sense movement of a fin by sensing movement of the user&#39;s toes, which may enhance the user&#39;s experience by enhancing the user&#39;s awareness of fin movement. Also, the user may control movement of the fin by controlling movement of the user&#39;s toes. Still further, allowing movement of the user&#39;s toes may permit more natural body movement that may avoid cramps and other potential disadvantages of other boot bindings systems that may not permit such foot movement. 
         [0064]    In many applications such as swimming and diving for example, a user faces downward in water. Further, many swimmers and divers have stronger downward kicks (that is, kicks downward when facing downward in water, or kicks that involve straightening or extending the leg at one or more of the hip, knee, ankle, and toe joints) when compared to their upward kicks (that is, kicks upward when facing downward in water, or kicks that involve flexing the leg at one or more of the hip, knee, ankle, and toe joints). In the embodiment shown, when a user kicks downward in such an orientation, resistance in surrounding water generally causes the fin  276 , the frame  108 , and the toe sole body  106  to deflect upward, or longitudinally relative to the posterior sole body  104  in the first deflection direction  214 . 
         [0065]    Therefore, as indicated above, in embodiments where the maximum longitudinal deflection in the first deflection direction  214  is a position where toes are fully extended forward (or anterior), then a downward kick (in an orientation where the user is facing downwards) in such embodiments will tend to deflect the fin  276 , the frame  108 , and the toe sole body  106  longitudinally relative to the posterior sole body  104  in the first deflection direction  214  to the maximum longitudinal deflection in the first deflection direction  214 , thereby extending the fin  276  away from the leg. When the fin  276  is extended away from the leg, the effective surface area of the fin  276  against incident water is increased by orienting the fin  276  generally perpendicular to a direction of motion of the fin  276 . Increasing effectiveness of the fin  276  during the downward kick may be desirable where the downward kick is relatively stronger than the upward kick. 
         [0066]    Also, in embodiments where the maximum longitudinal deflection range  218  ranges to maximum normal superior bending of metatarsophalangeal joints (such as about 30° to about 80° for example), then an upward kick (in an orientation where the user is facing downwards) causes the fin  276 , the frame  108 , and the toe sole body  106  to deflect longitudinally relative to the posterior sole body  104  in the second deflection direction  216 , thereby angling the fin towards the user&#39;s leg and reducing effective surface area of the fin  276  against incident water by orienting the fin  276  generally closer to parallel to a direction of motion of the fin  276  during the relatively weaker upward kick. Therefore, the longitudinal deflection range  218  in various embodiments may allow a fin such as the fin  276  to deflect longitudinally relative to a user&#39;s foot to increase and decrease effective surface area of the fin  276  during a kick cycle to increase effectiveness of the relatively stronger downward stroke while facilitating the relatively weaker upward stroke by reducing resistance during the upward stroke. 
         [0067]    Further, in embodiments where the longitudinal deflection range  218  is limited by a maximum longitudinal deflection in the second deflection direction  216  corresponding to a maximum normal superior bending of metatarsophalangeal joints (such as about 30° to about 80° for example), the longitudinal deflection range  218  may in some such embodiments prevent damage to metatarsophalangeal joints, or bones or other tissue surrounding the metatarsophalangeal joints, that could result from bending the metatarsophalangeal joints beyond normal bending. For example, when a user jumps out of a boat or off of a dock and into water feet-first, fins attached to the user&#39;s feet will naturally be deflected upward in response to resistance in the water surrounding the fin, and forcefully under the user&#39;s body weight and speed of motion. However, the longitudinal deflection range  218  in some embodiments may prevent such damage that could result from such forceful upward deflection of the fin  276 , in the embodiment shown because the stop surfaces  146  and  148  abut the stop surfaces  210  and  212  respectively to restrict longitudinal deflection of the toe sole body  106  relative to the posterior sole body  104  in the second deflection direction  216 . 
         [0068]    In the embodiment shown, the toe sole body  106  and the frame  108  both directly connect to the pivot  136 . However, in alternative embodiments, only one of the toe sole body  106  and the frame  108  may be connected directly to the pivot  136 . For example, in some embodiments, the frame  108  may not connect directly to the pivot  136 , but may connect instead to the toe sole body  106 . However, in such embodiments, the frame  108  may still be referred to as connected to the pivot  136  because the frame  108  is indirectly connected to the pivot  136  through the toe sole body  106 . 
         [0069]    Referring to  FIG. 16 , a frame  308  according to another illustrative embodiment is substantially the same as the frame  108  described above, but includes an actuator  310  in communication with one or more gears (not shown) that, when rotated, vary an angle  312  between a central longitudinal axis  314  of a fin connected to the frame  308  and a transverse axis  316  of a receptacle of the frame  308  for receiving a transverse pivot. For example, in some embodiments, a connector (similar to the connector  292  described above) of the frame  308  may be pivotally coupled to first and second laterally opposite frame elements (similar to the first and second laterally opposite frame elements  248  and  250  described above) of the frame  308  and the actuator  310  may be in communication with a pinion (not shown) on the connector of the frame  308  and in geared engagement with a static rack (not shown) on one of the first and second laterally opposite frame elements of the frame  308  such that rotation of the pinion causes the connector of the frame  308  to move along the rack, thereby pivoting the connector of the frame  308  relative to the first and second laterally opposite frame elements of the frame  308  and changing the angle  312 . In other embodiments where the connector of the frame  308  is pivotally coupled to the first and second laterally opposite frame elements of the frame  308 , the actuator  310  may be in communication with a worm (not shown) on the connector of the frame  308  and in geared engagement with a static worm gear (not shown) on one of the first and second laterally opposite frame elements of the frame  308  such that rotation of the worm causes the worm move along the static worm gear, thereby pivoting the connector of the frame  308  relative to the first and second laterally opposite frame elements of the frame  308  and changing the angle  312 . Adjusting the angle  312  may, for example, compensate for “pigeon-toed” or “bowlegged” foot orientations of some users, and more generally may allow users to vary angles between feet of the user and fins attached to the feet of the user. 
         [0070]    Referring to  FIGS. 17 and 18 , a toe sole body  318  according to another illustrative embodiment is substantially the same as the toe sole body  106  described above, but defines a threaded opening  320  for receiving a threaded fastener  322 . The threaded fastener  322  may also be received in a through-opening  324  of a retainer  326  such that the threaded fastener  322  retains the retainer  326  against first and second laterally opposite frame elements  328  and  330  of a frame  332  that is substantially the same as the frame  108 , and such that the retainer  326  retains the first and second laterally opposite frame elements  328  and  330  against a generally planar abutment surface  334  (similar to the generally planar abutment surface  184  shown in  FIGS. 1 ,  3 , and  15 ) to maintain the first and second laterally opposite frame elements  328  and  330  generally coplanar as described above with reference to  FIG. 15 . As indicated above, the frame  332  may thus be fastened to the toe sole body  318  such that the frame  332  and the toe sole body  318  move together, generally with longitudinal deflection relative to the posterior sole body in substantially similar angles. 
         [0071]    Referring to  FIG. 19 , a boot system according to another illustrative embodiment includes a toe sole body  336  and a frame  338 . The toe sole body  336  is substantially the same as the toe sole body  106  described above, but defines a recess shown generally at  340  on a top side shown generally at  342  of the toe sole body  336 . Referring to  FIGS. 19 ,  20 , and  21 , the recess is complementary to a projection  344  on a top side shown generally at  346  of the frame  338 . When the projection  344  contacts a surface  348  of the recess  340 , the surface  348  holds an upper surface  350  of the frame  338  against a lower surface  352  of the toe sole body  336 . A user wearing the boot of  FIG. 19  may thus “step in” to the frame  338  and fasten the frame  338 , and thus a fin (not shown) connected to the frame  338 , to the toe sole body  336  and thus to the boot. The surface  348  of the recess  340  and the lower surface  352  of the toe sole body  336  thus cooperate with the projection  344  and the upper surface  350  of the frame  338  to couple the frame  338  to the toe sole body  336  when the projection  344  is received in the recess  340  as shown in  FIG. 19 . As indicated above, the frame  338  may thus be fastened to the toe sole body  336  such that the frame  338  and the toe sole body  336  move together, generally with longitudinal deflection relative to the posterior sole body in substantially similar angles. The frame  338  also includes a resilient body  354 , which may be used as a heel strap positioned behind a heel end of the boot shown in  FIG. 19  to hold the projection  344  in the recess  340  and more generally to hold the frame  338  (and any fin, not shown, that may be attached to the frame  338 ) in connection with the toe sole body  336  for longitudinal deflection of the frame  338  together with the toe sole body  336  relative to a posterior sole body of the boot system of  FIG. 19 . 
         [0072]    Referring to  FIG. 22 , a boot system according to another illustrative embodiment includes a toe sole body  356  and a frame  358 . The toe sole body  356  and the frame  358  are substantially the same as the toe sole body  336  and the frame  338  respectively, except that the frame  358  does not include a heel strap and instead the toe sole body  356  and the frame  358  may be connected and disconnected by actuation of an actuator  360 , which in the embodiment shown extends over a top of the boot shown in  FIG. 22  when the actuator  360  is in a position (as shown in  FIG. 22 ) in which the frame  358  is connected to the toe sole body  356 . The actuator  360  may therefore be referred to as an “instep lever” by reference to the position of the actuator  360  when the frame  358  is connected to the toe sole body  356 . The frame  358  may be disconnected from the toe sole body  356  by pivoting the actuator  360  such that the actuator  360  moves away from the boot shown in  FIG. 22 . Further, a user wearing the boot of  FIG. 22  may “step in” to the frame  358  and fasten the frame  358 , and thus a fin (not shown) connected to the frame  358 , to the toe sole body  356  and thus to the boot. 
         [0073]    Referring to  FIGS. 22 and 23 , the actuator  360  is rotationally coupled to a pivot  362 , which in the embodiment shown includes a connection region rectangular in cross-section and having a width  364  in a first radial direction and a width  366  in a second radial direction different from (and perpendicular to in the embodiment shown) the first radial direction. The width  366  is greater than the width  364 . The frame  358  includes a connector  367  defining a receptacle shown generally at  368  open at an opening shown generally at  370 . The opening  370  has a height  371  greater than the width  364  but less than the width  366  such that the opening  370  may receive the connection region of the pivot  362  when the pivot  362  is oriented with the width  364  passing through the opening  370 . The pivot  362  may then be rotated (by actuation of the actuator  360 ) such that the width  366  is blocked from passing through the opening  370 , and the connector  367  is thus connected to the connection region of the pivot  362 . The pivot  362  may further be rotated (by actuation of the actuator  360 ) such that the width  364  may pass through the opening  370 , and the connector  367  is thus disconnected to the connection region of the pivot  362 . Alternative embodiments may include different ways of connecting to a connector such as the connector  367 . For example, in an alternative embodiment, actuation of the actuator  360  may translate a pivot in an axial direction relative to the pivot in and out of a receptacle such as the receptacle  368 . 
         [0074]    Referring to  FIG. 24 , a boot system according to another illustrative embodiment includes a toe sole body  372  and a frame  374 . The toe sole body  372  and the frame  374  are substantially the same as the toe sole body  356  and the frame  358  respectively, except that the actuator  376  of the toe sole body  372  extends over a toe of the boot of  FIG. 24  when the actuator  376  is in a position (as shown in  FIG. 24 ) in which the frame  374  is connected to the toe sole body  372 . The actuator  376  may therefore be referred to as a “toe lever” by reference to the position of the actuator  376  when the frame  374  is connected to the toe sole body  372 . The frame  374  may be disconnected from the toe sole body  372  by pivoting the actuator  376  such that the actuator  376  moves away from the toe region of the boot shown in  FIG. 24 . Again, a user wearing the boot of  FIG. 24  may “step in” to the frame  374  and fasten the frame  374 , and thus a fin (not shown) connected to the frame  374 , to the toe sole body  372  and thus to the boot. 
         [0075]    In general, the sole bodies described herein (such as the posterior sole bodies and the toe sole bodies described herein for example) may be molded into or otherwise formed in boot soles (such as the boot sole  112  shown in  FIG. 1  for example) to form integral boot soles connectable to frames that are in turn connectable to fins such as those described herein for example. Such sole bodies may be standardized and manufactured in one or in a small number of sizes, thereby possibly reducing manufacturing costs when compared to other boot binding systems, while boots (such as the boot  102  shown in  FIG. 1  for example) may be manufactured by a number of manufactures in a large number of varieties that may vary by foot size and shape, by material, by ankle support, and in many other ways. Further, fins (such as the fin  276  shown in  FIG. 12  for example) may also vary in many ways, such as in length, in width, in shape, in material, and in flexibility, for example. Nevertheless, such various boots and various fins may be interchangeable where the boots include standardized sole bodies (such as the posterior sole bodies and the toe sole bodies described herein for example) and where the fins are connectable to standardized frames (such as the frames described herein for example) connectable to such standardized sole bodies. Therefore, a user may interchange a variety of boots and a variety of fins to form combinations of particular boots and particular fins to suit particular purposes (for example, a boot suitable for cold water combined with a fin suitable for spear fishing, or a boot suitable for warm water combined with a fin suitable for snorkeling) without requiring entire flipper apparatuses to embody the desired features of both the boot and the fin. 
         [0076]    Although specific embodiments have been described and illustrated, such embodiments should be considered illustrative only and not as limiting the invention as construed according to the accompanying claims.