阅读说明：本技术 一种适于行走的脚蹼 (Flipper suitable for walking ) 是由 李·罗伊·普瑞斯 于 2018-05-30 设计创作，主要内容包括：一种穿在脚上的脚蹼,其特征在于,具有外侧鳍和内侧鳍,所述外侧鳍和内侧鳍未向前延伸超过脚蹼的鞋部的前端,形成用于接收脚的容器。另外,脚蹼与鞋部的鞋底间隔开,且比鞋底更靠近所述鞋部的鞋帮。(A fin to be worn on the foot, characterized by having an outer fin and an inner fin which do not extend forward beyond the front end of the shoe of the fin, forming a receptacle for receiving the foot. In addition, the flipper is spaced from the sole of the shoe portion and is closer to the upper of the shoe portion than the sole.)

1. A fin wearable on a user's foot, comprising: a shoe portion having a sole for receiving the portion of the foot thereon; and an upper supported above the sole by a lateral side and a medial side of the shoe portion in spaced relation to the sole, wherein the lateral and medial sides are connected between the sole and the upper for forming a receptacle of prescribed length extending longitudinally from a rear end to a front end of the shoe portion for receiving a user's foot therebetween;

the shoe portion including a heel strap at a rear end of the shoe portion, the heel strap being located at a position spaced rearwardly from a rear edge of the upper to define an ankle aperture therebetween, the ankle aperture opening laterally in a longitudinal direction of the shoe portion such that the ankle aperture is arranged to receive a foot therethrough so as to receive the foot therein;

the shoe portion includes a toe hole located at the front end and opening in a longitudinal direction of the shoe portion; and

a lateral fin and an medial fin located on respective ones of a lateral side and a medial side of the shoe portion, respectively, so as to extend outwardly in opposite directions from the shoe portion to respective distal ends of the lateral fins spaced from the shoe portion;

wherein the lateral fin and the medial fin extend from the ankle or adjacent positions of the shoe portion to the front end of the shoe portion, respectively, and do not extend beyond the front end;

and the lateral and medial fins are closer to an upper of the shoe portion than to a sole of the shoe portion.

2. The fin according to claim 1, wherein the front end of the shoe portion, which defines the toe hole, is inclined with respect to the longitudinal direction such that the inner shoe portion extends further forward from the rear end than the outer side of the shoe portion.

3. The fin as claimed in claim 1 or 2, wherein the front end of the shoe portion, which defines the toe hole, is convexly curved across the width of the shoe portion.

4. A fin as claimed in any one of claims 1 to 3, wherein the front ends of the outer and inner fins follow a common path across the width of the fin, the width of the fin sloping rearwardly from the distal end of the inner fin to the distal end of the outer fin.

5. A fin as claimed in any one of claims 1 to 4, wherein the toe aperture is defined between a forward end of the sole and a forward end of the upper, and the forward end of the sole extends forwardly at the toe aperture to a position further than the forward end of the upper of the shoe portion.

6. The fin as claimed in any one of claims 1 to 5, wherein the lateral fin is wider than the medial fin such that a distal end of the lateral fin is further from the shoe than a distal end of the medial fin.

7. The fin as claimed in any one of claims 1 to 6, wherein the lateral fin and the medial fin are thickened outboard and inboard of the shoe relative to the body thickness of the lateral fin.

8. A fin as claimed in any one of claims 1 to 7, wherein the lateral fin and the medial fin each include a rib extending from the shoe in an outward direction transverse to the longitudinal direction so as to provide bend-resistant reinforcement of the lateral fin in a direction longitudinally transverse to the shoe.

9. The fin according to claim 8, wherein the ribs are inclined to extend obliquely outward toward the front.

10. A fin as claimed in any one of claims 1 to 9, wherein the outer fin and the inner fin are thickened at their distal ends such that each fin further includes a stiffening member at its distal end parallel to the longitudinal direction of the shoe portion.

11. A fin as claimed in any one of claims 1 to 10, wherein each of the lateral fin and the medial fin is curved in the longitudinal direction from front to rear so as to have a convex upper surface and a concave lower surface.

12. The fin as claimed in claim 11, wherein the lateral fin and the medial fin extend linearly outward from the shoe to distal ends thereof.

13. The fin according to any one of claims 1 to 12, wherein rear portions of the lateral and medial fins are spaced further above a plantar plane defined by a sole of the shoe portion than front portions of the lateral and medial fins.

14. The fin according to any one of claims 1 to 13, wherein the rear portion of the lateral fin extends further rearward than the rear end of the medial fin.

15. The fin according to any one of claims 1 to 14, wherein the front ends of the lateral and medial fins follow a common curved path across the width of the fin, the common curved path being substantially aligned with and parallel to the front end of the shoe.

16. The fin as claimed in any one of claims 1 to 15, wherein the heel strap is adjustable in length so that the prescribed length of the container is adjustable.

17. A fin as claimed in any one of claims 1 to 16, wherein the upper includes a strap member that is adjustably secured between the lateral side and the medial side such that the maximum circumference of the container defined by the shoe portion is adjustable.

18. A fin as claimed in any one of claims 1 to 16, wherein the upper of the shoe portion includes a gusset supported therein by an elastic material such that the perimeter of the container defined by the lateral side, medial side, upper and sole is elastically adjustable.

19. The fin according to claim 18, wherein the upper of the shoe portion further includes a strap member adjustably secured between the lateral side and the medial side such that a maximum circumference of the container defined by the shoe portion is defined by the strap member, the strap member being externally supported on the gusset of resilient material.

20. A fin wearable on a user's foot, comprising:

a shoe portion having a sole for receiving the portion of the foot thereon; and an upper supported above the sole by a lateral side and a medial side of the shoe portion in spaced relation to the sole, wherein the lateral and medial sides are connected between the sole and the upper for forming a receptacle of prescribed length extending longitudinally from a rear end to a front end of the shoe portion for receiving a user's foot therebetween;

the shoe portion including a heel strap at a rear end of the shoe portion, the heel strap being located at a position spaced rearwardly from a rear edge of the upper to define an ankle aperture therebetween, the ankle aperture opening laterally in a longitudinal direction of the shoe portion such that the ankle aperture is arranged to receive a foot therethrough so as to receive the foot therein;

the shoe portion includes a toe hole located at the front end and opening in a longitudinal direction of the shoe portion;

wherein a front end of the shoe portion defining the toe aperture is inclined relative to the longitudinal direction such that a shoe portion of the medial side extends further forward from the rear end than a lateral side of the shoe portion; and

a lateral fin and a medial fin located on respective ones of a lateral side and a medial side of the shoe portion, respectively, so as to extend laterally outwardly from the shoe portion to respective distal ends of the lateral fins spaced from the shoe portion;

wherein the lateral fin and the medial fin each extend from a rear portion of the lateral fin toward a front portion of the lateral fin at a location at or near the location of the ankle hole of the shoe portion, the front portion of the lateral fin being a rear portion of a front end of the shoe portion;

the lateral fin and the medial fin are spaced upward from a sole of the shoe portion along a length of the shoe portion between a front and a rear of the lateral fin; and

the rear portions of the lateral and medial fins are spaced higher than the front portions thereof relative to a plantar plane defined by the sole of the shoe portion.

Technical Field

The present invention relates generally to flippers wearable on a user's foot, and more particularly to such flippers adapted to be walked over a surface.

Background

Disclosure of Invention

According to an aspect of the present invention, there is provided a flipper wearable on a user's foot, comprising:

a shoe portion having a sole for receiving the portion of the foot thereon; an upper supported above the sole by lateral and medial sides of the shoe portion, spaced from the sole, wherein the lateral and medial sides are connected between the sole and the upper for forming a receptacle of prescribed length extending longitudinally from a rear end to a front end of the shoe portion for receiving a user's foot therebetween;

the shoe portion including a heel strap at a rear end of the shoe portion, the heel strap being located at a position spaced rearwardly from a rear edge of the upper to define an ankle aperture therebetween, the ankle aperture opening laterally in a longitudinal direction of the shoe portion such that the ankle aperture is arranged to receive a foot therethrough so as to receive the foot therein;

the shoe portion includes a toe hole located at a front end and opened in a longitudinal direction of the shoe portion; and

an outer lateral fin and an inner lateral fin located on respective ones of an outer side and an inner side of the shoe portion, respectively, so as to extend outwardly in opposite directions from the shoe portion to respective distal ends of the lateral fins spaced from the shoe portion;

wherein the lateral fin and the medial fin extend from the ankle or adjacent positions of the shoe portion to the front end of the shoe portion, respectively, and do not extend beyond the front end;

and the lateral and medial fins are closer to the upper of the shoe portion than to the sole of the shoe portion.

This minimizes the interference of the side fins with walking as they recede rearward from the forward-most end of the toes and are spaced upward from the ground.

In one embodiment, a forward end of the shoe portion (where the toe aperture is defined at the forward end of the shoe portion) is inclined relative to the longitudinal direction such that the medial shoe portion extends further forward from the rear end than the lateral side of the shoe portion.

In such embodiments, the forward end of the shoe portion (where the toe aperture is defined at the forward end of the shoe portion) may be convexly curved across the width of the shoe portion.

Alternatively, the front end of the shoe portion may be linear across the width of the shoe portion.

The front ends of the lateral and medial fins may follow a common path across the width of the flipper that is substantially parallel to the front end of the shoe.

The common path may be curved and spaced from a forward end of the shoe portion, which is also curved.

Preferably, the front ends of the lateral and medial fins follow a common curved path across the width of the flipper substantially aligned with the front end of the shoe.

Thus, the shoe portion may be arranged to receive the foot such that the path of the front end of the shoe portion and the front end of the lateral fin is substantially parallel to the bending axis of the ball region. The ball region is the location of the metatarsal heads.

The sole portion of the forward end (which defines a toe hole along the sole of the shoe portion) may extend further than the upper portion of the forward end (which defines a toe hole along the upper of the shoe portion).

The flipper may further include a heel aperture at or near a rear end opposite the ankle aperture such that the heel protrudes from the heel aperture when the foot is received in the shoe.

In the embodiment shown, the outer fins are wider than the inner fins; however, in another embodiment, the outer side fin and the inner side fin may be substantially symmetrical to each other.

Preferably, the lateral and medial fins are thickened on the lateral and medial sides of the shoe portion.

Preferably, the lateral and medial fins each include a rib extending laterally from the shoe portion to the longitudinal direction in an outward direction to reinforce the lateral fin in the outward direction. The ribs may extend outwardly at an incline in the forward inclination direction.

The lateral and medial fins are preferably thickened at their distal ends such that each lateral fin further includes stiffening members at its distal end that are parallel to the longitudinal direction of the shoe portion.

Each of the lateral and medial fins may be longitudinally curved from front to back, having a convex upper surface and a concave lower surface.

Typically, the lateral and medial fins extend linearly outward from the shoe portion to the distal end thereof.

The rear portions of the lateral and medial fins may be spaced further above a plantar plane defined by the sole of the shoe portion than the front portions of the lateral and medial fins.

Preferably, the rear portion of the lateral fin extends more rearwardly than the rear end of the medial fin.

In some embodiments, the length of the heel strap is adjustable such that the prescribed length of the container is adjustable.

The upper of the shoe portion may further include a strap member adjustably secured between the lateral side and the medial side such that a maximum circumference of the container defined by the shoe portion is adjustable.

The upper of the shoe portion may further include a gusset made of an elastic material supported therein such that a perimeter of the container defined by the side, medial side, upper and sole is elastically adjustable. When both the strap member and the gusset of resilient material are provided on the upper, the strap member is preferably supported externally by the gusset of resilient material.

According to another aspect of the present invention, there is provided a fin wearable on a foot of a user, including:

a shoe portion having a sole for receiving a portion of a foot thereon; an upper supported above the sole by sides and a medial side of the shoe portion spaced from the sole, wherein the sides and medial side are connected between the sole and the upper for forming a receptacle of a prescribed length extending longitudinally from a rear end to a front end of the shoe portion for receiving a user's foot therebetween;

the shoe portion including a heel strap at a rear end of the shoe portion, the heel strap being located at a position spaced rearwardly from a rear edge of the upper to define an ankle aperture therebetween, the ankle aperture opening laterally in a longitudinal direction of the shoe portion such that the ankle aperture is arranged to receive a foot therethrough so as to receive the foot therein;

the shoe portion includes a toe hole at a front end, which is open in a longitudinal direction of the shoe portion;

the front end of the shoe portion within which the toe hole is defined is inclined with respect to the longitudinal direction such that the inner shoe portion extends forward from the rear end, further than the outer side of the shoe portion;

and an outer lateral fin and an inner lateral fin located on respective ones of the lateral side and the inner side of the shoe portion, respectively, so as to extend outwardly from the shoe portion in opposite directions to the longitudinal direction to respective distal ends of the lateral fins spaced from the shoe portion;

wherein the lateral fin and the medial fin each extend from a rear portion of the lateral fin to a front end of the lateral fin, the rear portion of the lateral fin being located at or near an ankle hole of the shoe portion, and the front end of the lateral fin being rearward of the front end of the shoe portion;

wherein the lateral fin and the medial fin are spaced upward from a sole of the shoe portion along a length of the shoe portion between a front and a rear of the lateral fin;

wherein the rear portions of the lateral and medial fins are spaced higher than the front portions thereof relative to a plantar plane defined by the sole of the shoe portion.

Any of the features described above may be combined with each other.

Drawings

An exemplary embodiment of the invention will now be described with reference to the accompanying drawings, in which:

fig. 1 is a perspective view of the front and side surfaces of a fin according to the present invention.

Fig. 2 is a perspective view of the front and inner sides of the flipper according to the embodiment of fig. 1.

Fig. 3 is a top plan view of the flipper according to the embodiment of fig. 1.

Fig. 4 is a bottom plan view of the flipper according to the embodiment of fig. 1.

Fig. 5 is a front elevational view of the flipper according to the embodiment of fig. 1.

Fig. 6 is a rear elevational view of the flipper according to the embodiment of fig. 1.

Fig. 7 is a side elevational view of the embodiment of fig. 1.

Fig. 8 is a medial elevational view of the flipper according to the embodiment of fig. 1.

Fig. 9 is a cross-sectional view taken along line 9-9 in fig. 3.

In the drawings, like reference numerals designate corresponding parts throughout the different views.

Detailed Description

In the drawings there is shown a fin 10 adapted to be worn on the foot of a user (not shown) for walking. It will be appreciated that although only one fin is described herein, which as shown is particularly adapted to be worn on the right foot, the fins are typically sold in pairs and the other of the two fins is symmetrical to the fin as shown herein.

The fin 10 includes a shoe 12, the shoe 12 defining a receptacle 13 for receiving a foot. Thus, the receptacle 13 of the shoe portion 12 includes a rear end 15, the rear end 15 being located at or adjacent a rear of the heel of the wearer received in the shoe portion, and the rear end 15 extending longitudinally to a front end 16 of the receptacle. In addition, the shoe portion has an outer side 19 and an inner side 20, which correspond to the outer side of the foot (on the side of the little toe) and the inner side of the foot (on the side of the big toe or the thumb toe), respectively.

In addition, the shoe portion includes an upper 22, the upper 22 spanning from the rear edge at the ankle opening 23 to the front end 16 of the shoe portion. The ankle hole 23 is thus defined between the rear edge and the rear end of the upper of the shoe portion, as defined in further detail below, such that the ankle hole opens transversely to the longitudinal direction of the shoe portion, and more particularly upwardly, such that the foot first passes the ankle hole toe in order to receive the foot in the shoe portion. The upper 22 is attached by the sidewalls of the lateral side 19 and the medial side 20 at a location above the sole 25 of the shoe portion to collectively define a perimeter of the shoe portion around the shoe portion that receives the foot of the user in use.

The upper 22 includes a gusset 21 supported therein by a resilient material such that the perimeter of the container defined by the lateral side, medial side, upper and sole is resiliently adjustable. In the illustrated embodiment, the sole 25, medial side 20, lateral side 19, and a majority of the upper are formed of a generally resilient material that is flexible, but stiff enough to substantially retain its shape, thereby providing minimal elastic stretch. However, the gusset 21 is formed of a softer and more elastic material that stretches more easily than the material of the rest of the shoe portion so that the circumference of the shoe support can be easily adjusted at the area of the gusset.

Upper 22 also includes strap member 24 adjustably secured between the lateral and medial sides of the upper on opposite sides of gusset 21. The length of the strap member is adjustable and less elastic than the gusset plate. Thus, once the user selects the length of the strap member between the opposite sides of the gusset, the strap member defines the maximum circumference of the container. In the illustrated embodiment, the strap member is secured to the upper on one side of the gusset and passes through a loop structure secured to the upper on the other side of the gusset such that the free end of the strap member can be secured at a series of locations along the middle portion of the strap member, for example using mating hooks and loops. In alternative embodiments, the adjustable strap member 24 may be defined by a strap, a quick ratchet system, or any other structure adjustable in length between opposite sides of the gusset.

The strap member is supported to span externally over the gusset of the elastic material. In this way, the gusset provides comfort for different instep heights while protecting the top of the foot from the adjustable strap member, which can adjust the foot cavity to fit different instep heights and different foot widths.

The sole 25 of the shoe portion opposite the upper 22 spans from the rear edge at the heel aperture 26 to the front end 16. The heel hole 26 is opposite the ankle hole 23 and opens in a lateral direction opposite the ankle hole 23, opening downward such that the heel of the foot protrudes from the heel hole when the foot is received in the shoe portion. The bottom surface of the sole 25 includes a texture formed by a series of longitudinal and transverse grooves 27 that pass between the two ends and opposite sides of the sole. The grooves 27 thus define a tread pattern capable of directing water longitudinally and transversely around the sole when the sole 25 is treaded on standing water on the ground on which the user is walking, which functions similarly to a tread pattern on a vehicle tyre.

In the illustrated embodiment, both the ankle aperture 23 and the heel aperture 26 are located at the rear end of the shoe portion, such that the shoe portion forms a thin heel strap 28 at the rear end, which is adapted to wrap from side to side around the rear of the wearer's heel. Although the heel strap 28 may be integrally formed with the remainder of the shoe portion, in the illustrated embodiment the heel strap 28 is an adjustable strap that is attached to opposite ends of the lateral and medial sides of the shoe portion, respectively. The prescribed length of the receptacle of the shoe portion is defined between the heel strap 28 at the front end 16 and rear end 15 of the shoe portion so that the prescribed length of the receptacle is adjustable when the heel strap 28 comprises a strap of adjustable length as shown. Hinge members 29 connect each end of heel strap 28 with a respective side of the shoe portion such that heel strap 28 pivots about a common axis in the lateral direction between the two hinge members 29. The strap of the heel strap supports the heel cup 31 in the center of the heel cup 31, which is constructed of a block of resilient material (e.g., expanded foam) having an ergonomically concave interior surface to readily conform to the shape of a user's heel in a comfortable manner. Each of the opposite ends of the strap members forming the heel strap 28 are threaded through the loop formations on the respective hinge members 29 and then adjustably secured along the middle portion of the strap, for example using cooperating hook and loop fasteners, to allow adjustment of the length of the strap and to allow adjustment of the length of the two ends of the strap, with the heel cup positioned between the opposite sides of the shoe portion, maintaining the center.

At the front end 16 of the shoe portion, a toe aperture 30 is defined that opens in a forward longitudinal direction. The front end 16 is spaced forwardly from the rear end 15 by a prescribed length L such that the shoe portion 12 is arranged to receive a foot. The flipper 10 is worn in such a manner that the toes of the foot do not project substantially beyond the front end 16, and the ball regions defined by the positions of the metatarsal heads are spaced rearwardly of the front end 16 when the foot is received in the shoe. Generally, flippers are produced and sold in a single size or a limited number of sizes, each size being intended to fit a corresponding range of feet of different sizes, such that the wearer's foot is retained in the shoe between the upper 22, the sole 25 and the heel strap 28 at the rear end 15. Thus, the toes of different wearers may extend beyond the front end 16 by different amounts, but in general the ball regions are intended to be located within the shoe portion 12 near the front end 16. In this manner, when the foot is received in the shoe portion 12, the foot is substantially enclosed by the shoe portion 12.

According to the illustrated embodiment, the shoe portion may be available in several different sized configurations, wherein each sized configuration relies on the adjustable heel strap 28 to accommodate a range of feet having different shoe sizes. Furthermore, the use of the combination of the resilient gusset 21 and the strap member 24 to adjust the circumference of the shoe container relative to the width or height of the user's foot also allows for accommodation of a range of feet having different shoe widths or heights.

At the other end of the shoe portion, lateral and medial fins 33, 34 are provided on respective ones of the lateral and medial sides 19, 20 of the shoe portion. Each lateral fin 33, 34 forms a substantially rigid wing on one side of the shoe portion, extending widthwise from the shoe portion laterally to a free distal side 33A, 34A of the respective lateral fin. Each lateral fin also extends longitudinally of the shoe portion from a location spaced from the rear end 15 of the shoe portion so as to be adjacent a respective rear end 33B in the illustrated embodiment, 34B of the lateral fin to a front end 33C, 34C of the respective lateral fin, which is located no further forward than the front end 16 of the shoe portion. More specifically, in the illustrated embodiment, the front ends 33C and 34C are spaced rearwardly from the front end 16 and do not project forwardly from the front end 16.

As shown in fig. 3 and 4, the front end 16 of the shoe part is shaped to correspond to the ball regions, which are not perpendicular to the longitudinal direction, in order to be more comfortable to walk. The ball region is the padded part of the ball of the foot between the toes and the arch, generally defining the bending axis of the ball region, and during walking gait the metatarsals of the foot extend upwards relative to the phalanges heads of the foot, while the phalanges heads remain on the support surface. The foot may be considered to have a longitudinal axis extending from the heel through the second toe adjacent the innermost big toe. The foot flexion axis is perpendicular to the longitudinal axis and is inclined relative thereto such that the metatarsal heads leading to the big toes are more forward than the metatarsal heads leading to the small toes. The flexion axis is an approximate axis that extends through a convexly arcuate path connecting the metatarsal bones from the medial to the lateral foot. Thus, front end 16 is inclined relative to the longitudinal direction such that the shoe at medial side 20 extends farther forward from rear end 15 than lateral side 19 of shoe 12. More specifically, the front end is convexly curved, as shown by the dashed line P1, across the entire width of the shoe portion from the medial side 20 to the lateral side 19, more closely approximating the shape of the ball of the foot, rather than having a linear extent from one side to the other, for example. The sole portion of the shoe portion is sufficiently flexible to follow the bending of a user's foot during bending to define a bending axis of the sole portion that traverses across its width at the forward end of the shoe portion to align parallel with the bending axis of the user's foot. In the illustrated embodiment, the shoe bottom 16S, which defines the forward end of the toe hole 30 along the shoe bottom 25, extends forward, further than the forward heel portion 16U, which defines the toe hole along the shoe upper 22, which may improve the bending of the shoe according to a walking gait.

The rear ends 33B, 34B of the lateral fins each extend forward from the boot portion to the respective side so as to be inclined with respect to the longitudinal direction of the boot portion and to be inclined in an opposite manner to the rear end of the other lateral fin.

To avoid inhibiting the flexion of the foot in walking gait, the front ends 33C, 34C of the lateral and medial fins 33, 34 traverse the full width of the flipper along a common arcuate path, as indicated by the dashed line P2, from one distal end 33A to the other distal end 34A, which is parallel to the curved shape or path P1 of the forefoot front end 16. That is, the leading end of each lateral fin defines and lies along an arcuate path P2. If the front ends 33C, 34C of the lateral fins are located at the front ends rather than being disposed rearwardly from the rear ends as in the illustrated embodiment, the paths P1 and P2 will further define a common arcuate path. The path P1 defined by the front end 16 is arranged to follow the curvature of the bending axis of the foot in order to make walking easier when the fin 10 is worn, when the front end 16 is in front of or near the bending axis. It should be appreciated that in the illustrated embodiment, path P2, which is immediately followed by the front ends 330 and 34C of the lateral fins, is spaced rearwardly from path P1, where path P1 is immediately followed by the front end 16 of the shoe portion, but path 1 and path 2 are spaced slightly apart so that the front ends of the lateral and medial fins remain substantially aligned with the front end of the shoe portion.

The lateral and medial fins 33, 34 are completely spaced from the sole 25 of the shoe portion and include thickened distal ends 33A and 34A, with the distal ends 33A and 34A flaring up and down from the body 35 of the respective lateral fin. More specifically, the lateral fins are closer to the middle of upper 22 and sole 25. The shoe portion 12 (defining a tubular container from the front end 16 to each of the ankle and heel apertures 23, 26) is rounded at each of the lateral and medial sides 19, 20 from the sole 25 to the upper 22, and in the illustrated embodiment, the lateral fins 33, 34 meet the boot portion with the container walls sloping upwardly and inwardly toward the center of the upper 22. Thus, lateral fins 33, 34 do not interfere with walking gait, particularly when the foot may roll from side to side (usually from medial to lateral).

In the illustrated embodiment, the width of the lateral fin 33 from the lateral side 19 of the shoe portion to the distal end 33A of the fin is wider than the width of the medial fin 34 from the medial side 20 to the distal end 34A. Thus, the fins collectively provide sufficient surface area to enhance swimming (when the flipper is worn on the foot for swimming), while the inner fins are of a smaller size so that the wearer's feet can walk separately at a comfortable width.

The length of the two lateral fins is similar, but the outer fin 33 is slightly longer 14 than the inner fin 34. The front end 34C of the inboard fin is closer to the rear end 15 than the front end 33C of the outboard fin, and thus in the illustrated embodiment, the rear end 34B of the inboard fin is closer to the rear end 15 than the rear end 33B of the outboard fin.

The length of the outer fin along its distal end 33A is shorter than the length of the inner fin 34 at 34A, such that the rear end 33B of the outer fin extends further forward than the rear end of the inner fin. In addition, the lateral fins may have their front ends 33C extending rearwardly from the lateral side 19 to their distal ends 33A, rather than being substantially transversely perpendicular to the sides of the shoe portion, as in the medial fins, so that the lateral fins 33, 34 are similar in their body surface areas, although they are shaped differently. The outer fins 33 are substantially trapezoidal, while the inner fins 34 are substantially rectangular in comparison.

Each lateral fin 33, 34 includes strengthening ribs 37 at the top and bottom of the body 35, each at spaced locations on the body 35. The rib 37 is substantially triangular in plan view, extending longitudinally with a ramp, so as to extend laterally outwardly and forwardly from the respective side 19, 20 of the shoe portion to a location spaced inwardly from the outer periphery of the side fin defined by its distal, rear and forward ends respectively, to which A B and C are appended after the reference numeral corresponding to the side fin. The ribs serve to reinforce the respective lateral fins against bending in width. Further, in the illustrated embodiment, all of the ribs effectively interface with the walls of the boot portion, thereby acting to reduce and limit bowing of the lateral fins relative to the boot portion.

The ribs 37 in the illustrated embodiment are curved to be closer to being parallel to the longitudinal direction at the outer end furthest from the shoe than the inner end connected to the shoe. Thus, the distal end of the rib has a smaller slope with respect to the longitudinal direction relative to the proximal end of the rib. In this manner, water around the shoe portion flows laterally outward from the shoe portion from the top and bottom surfaces of the rib through the proximal end of the rib, and then redirects the water flow across the respective faces of the lateral fins so that it flows more longitudinally toward the leading edges of the lateral fins, respectively, distal to the rib.

The lateral fins are also thickened on the top and bottom at the proximal ends 33D, 34D of the shoe portion for rigid connection thereto. More specifically, the thickness of the proximal end of the lateral fins is thicker than the main portion of each lateral fin. Ribs 37 extend outwardly from these thickened proximal ends 33d, 34d to a location spaced from the outer periphery of the respective lateral fins. The ribs also define regions of greater thickness in height than the main portion of each side fin between the upper and lower surfaces thereof.

Furthermore, the distal ends 33A, 34A of the lateral fins are thickened in the longitudinal direction of the shoe portion to define stiffening members extending in the longitudinal direction of the shoe portion to resist bending in the longitudinal direction, in particular at or near the outer periphery of the lateral fins. The distal ends 33A, 34A are rounded at their forwardmost tips to a maximum thickness from which the thickness tapers to the posterior end of the respective lateral fin, thereby being generally teardrop-shaped.

The rear and front ends of the side fins are no higher than the body 35, and the body 35 may facilitate water flow longitudinally along the respective side fins from the rear ends to the front ends of the side fins during swimming. However, the wider front ends 33C, 34C of the lateral fins are thinner and the narrower rear ends 33B, 34B are thicker, as shown in FIGS. 5 and 6.

Thus, the lateral and medial fins 33, 34 are self-supporting and relatively stiff.

The body 35 of each lateral fin is convexly curved relative to the sole 25 in the longitudinal direction from the rear end to the front end, but is not curved from the proximal end to the distal end, such that the respective lateral fin extends linearly outward from the shoe portion. Thus, a convex upper surface 35A and a concave lower surface 35B are provided.

The flared distal ends 33A, 34A of the lateral fins extend upwardly from the upper surface 35A and downwardly from the lower surface 35B, respectively, of the respective lateral fins, thereby forming vertical walls above and below the body 35 that serve as longitudinal water guides during swimming.

The front ends 33C, 34C are closer to, in particular at the center of, a horizontal plantar plane PT of the shoe portion defined by the sole 25 than the rear ends 33B, 34B, which in the embodiment shown is lower than the lateral and medial sides of the sole. The plantar surface PT is parallel to the plane defined by the portion of the wearer's ball of the foot that is located behind the ball of the foot and separates this plane from the support surface during walking.

Since my invention is susceptible to various modifications and alternative embodiments, as described above, there are numerous clearly distinct embodiments of the same, and it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.