Collapsible swimming fins system for unidirectional thrust

Abstract

The system is configured as a modified swimming shoe with integrated support for collapsible fins positioned above the arch for short fins or above the arch and at the back of the swimming shoe to accommodate bigger fins. The system allows for maximum thrust during the power stroke while the resistance during the return stroke is no different from that of a barefoot swimmer due to the fins' passively switching to the collapsed position that closely mimics the dimensions of the foot. The resulting net efficiency of the propulsion thrust is much greater, and the complete movement (power stroke and return stroke) requires less energy and oxygen consumption. Collapsible fins offer greatly enhanced maneuverability by allowing abruptly changing direction and speed. The collapsible wrist fins further increase the efficiency of swimming while allowing the hand to remain free for other tasks.

Description

BACKGROUND OF THE INVENTION

The present disclosure relates to collapsible fin footwear for swimming. More specifically, the present disclosure refers to swimming shoes with collapsible fins mounted above the arch of the foot that allow for more efficient swimming or diving, and greater speed and maneuverability, while not impeding walking in shallow water or on land.

Typical swim fins are intended to aid propulsion through the water. With relatively minor modifications of size, stiffness, length, and geometry, they are utilized for a variety of activities and purposes including recreation, training, swimming, snorkeling, diving, etc. The common drawback of a traditional fin design is a poor resistance ratio between power thrust and return movement of the foot, the need for physiologically and anatomically awkward undulating movements, and the inconvenience during the transition from water to land and vice versa.

Searching available databases, we were unable to find patents for devices that are meaningfully comparable with our invention. As examples, we present patented devices that share some technical aspects and may serve to illustrate unique and differentiating aspects of the present invention.

U.S. Pat. No. 4,752,259A (by Edd Tackett and Hubert Tackett) describes a traditional fin composed of separate inner and outer fragments connected by hinges so that the fin can be folded to facilitate walking. The introduction of the rotating element is the only similarity with our invention. Unlike our invention, the patent does not significantly depart from classical design, and it does not address or solve the problems of more efficient swimming, maneuvering, anatomical compatibility, and overall convenience.

U.S. Pat. No. 7,736,208B2 (by Carrie L. Bonis and Kostanteno Bonis) describes an amphibious shoe with a fin compartment within the sole. This invention allows for unimpeded walking on dry land or in shallow water. Another component of the invention is retractable fins with the ability to change their surface and geometry. The similarity of this invention is, however, superficial. This design utilizes the traditional concept of the fins being an extension of the sole's plane, and it does not passively minimize the resistance of the fins during return movement after the power stroke.

U.S. Pat. No. 4,264,994A (by Giovanni M. Carbone) describes articulated fins for hands and feet. These fins are composed of the cartilagineous membrane attached to 2 or 3 articulated ribs. While swimming, the fins bend downward during the return movement of the leg thus reducing resistance and improving net thrust in the desired direction. This design is mechanically complex (multiple joints and springs) and, therefore, prone to malfunction. In comparison, the present invention is extremely simple and is not expected to be easily damaged. Also, in this design, even when the front (i.e., widest) side of the flipper is folded, the resulting reduction of resistance is relatively low. In comparison, the present invention implies that all movements of the fins are passive, and in a closed position they stay within the dimensions of the foot. In addition, the springs are supposed to force flippers into an “open” position for walking on land. In the present invention, the fins are positioned above the swimming shoe, and, therefore, walking on land does not require any additional structural elements.

Overall, there is a substantial difference in both design and underlying principles between the present invention and prior art. The present invention remedies the drawbacks of traditional fin designs and significantly improves the efficiency of swimming.

SUMMARY OF THE INVENTION

The present invention provides a new swimming fin system which is a more efficient and comfortable alternative to traditional fins that are currently on the market. The new system is devoid of numerous drawbacks typical for an existing one including low efficiency of the power thrust due to significant drag during the return movement. The new system also offers greater maneuverability and eliminates inconveniences associated with walking on land.

The new system is comprised of four primary components: a swimming shoe, integrated with the sole of the shoe support frame for mounting fins, fins, and the means for blocking the fins from exceeding a certain angle when opening.

The fins are positioned above the arch of the foot, their length may be variable depending on the purpose including recreational swimming, training, snorkeling, diving, and other forms of activity. The width of the fins can also be modulated by changing the thickness of the sole and/or the height of the support frame. The geometry of the fins also depends on the primary requirement to not impede walking on land. In some applications, the fins may extend beyond the heel; in that case, additional modifications of the support frame, such as the incorporation of an additional support prong behind the heel section of the swimming shoe, will be required.

The support frame is composed of two or more prongs on both sides of the swimming shoe merging above the arch to form a mounting bridge for the fins. The various versions of devices for stopping fins from exceeding a certain angle (90 O or 180O) in an “open” position can be mounted above or below the fins.

The maximum thrust and minimum resistance during the return movement of the leg are based on the passive opening and closing of the fins at the start of the movement. Other aspects of the present invention will be elucidated in the following detailed description accompanied by drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows from different angles one of the possible designs for a swimming shoe with short collapsible fins and an external flat stop. 1—swimming shoe; 2—fin; 3—external flat stop; 4—closed position, minimum resistance during the return movement; 4—open position, maximum thrust during the power stroke; 5—fins with a flexible connector; 6—the support structure integrated with the sole of the swimming shoe.

FIG. 2. shows from different angles one of the possible designs for a swimming shoe with large collapsible fins extending beyond the heel. A swimming shoe with larger fins and external flat stops. 1—larger fins extending beyond the heel; 2—closed position, minimum resistance during the return movement; 3—open position, maximum thrust during the power stroke; 4—modification of the support structure with an additional prong at the back of the swimming shoe; 5—an additional external flat stop to limit the motion of the back portion of the extended fin.

FIG. 3 shows schematics of a range of possible designs for stopping a rotating portion of the fins. Various embodiments of contraptions for limiting the range of fins' motion. 1—external flat stop; 2—external stop using corners; 3—stop attached to the support structure underneath the fins; 4—strings or membranes attached to the support structure underneath the fins; 5—180O hinge attached to both fins; 6—90O hinges limiting motion of individual fins.

FIG. 4 shows an overall design for wrist fins. The illustration of one of the embodiments of the wrist fins with external stop. 1—hand; 2—wrist glove living fingers uncovered; 3—fins; 4—external flat stop for fins connected with flexible material.

DETAILED DESCRIPTION OF THE INVENTION

The following review and figures are considered illustrative of the principles of the invention. The invention itself is not limited to the specific materials, variants of components, combinations thereof, and prototypes chosen for demonstration because there are many possible permutations of the design based on the same principle.

The invention addresses and resolves major drawbacks of traditional fins. It enhances thrust efficiency, maneuverability, and ease of transition from land to water and vice versa. As per this invention, the ratio of thrust generated during the power stroke and the return movement of the foot decidedly shifts in favor of the power stroke. Since return movement causes the passive collapse of the fins to the closed configuration, the resistance generated by a return movement is not different from the resistance of the foot without the fin. Similarly, minimum resistance during the return movement allows for an abrupt change of direction if necessary. Walking on land is facilitated by the fact that, while the fins are in a collapsed configuration, the edge of the fins is positioned above the sole of the swimming shoe and designed to be not in the way during walking or running.

The system is integrated with the sole of the swimming shoe (FIG. 1:4) although, in other possible embodiments, it may be constructed as a separate unit attachable to any swimming shoe using straps. The support frame is composed of the sole portion and several prongs (2-4) bent or curved so that they do not go beyond the dimensions of the footprint. The prongs on both sides merge above the arch of the foot at 1 inch or more and form a bridge for the attachment of the fins and stop devices (FIG. 1:4).

The fins can have various shapes and sizes and be flat or curved to better accommodate the shape and dimensions of the foot in “closed” position (FIG. 1:2,5,6,7). The primary limitation of fins' size and shape is to not impede the movement of the foot and to remain above the ground when standing and moving on a solid surface. The width of the fins, however, can be extended using increasing the thickness of the sole and/or the height of the support frame. In the variant of the design depicted in the figures (FIG. 1-3), the left and the right fins are connected by a flexible synthetic membrane (FIG. 1:7) at around 0.5 inches or more. The highly flexible synthetic membrane is affixed to the bridge formed by the support frame along the center line between the fins.

In the variant of the design depicted in the figures (FIGS. 1-3), the optimal rotation angle of the fins is enforced by placing an external stop above the fins (FIG. 1:3, shape and size may vary), so that fins provide the widest area during the power stroke in an “open” position (FIG. 1:6; FIG. 2:5). In other variants of the system the rotation of fins may be regulated by other types of external/internal stops or hinges (FIG. 3). During the return stroke, the fins passively assume a “closed” position (FIG. 1:5; FIG. 2:4) thus reducing the area causing resistance to the dimensions of the swimming shoe, i.e., smallest possible.

When necessary, the system can accommodate longer fins. The attachment of longer fins (FIG. 2:1) requires a modified support frame with a complimentary prong, a bridge for the extended portion of the fins (FIG. 2:6), and the addition of a secondary stop behind the heel of the swimming shoe (FIG. 2:2).

Utilizing similar principles, the present fin system for feet is complemented by the swimming fin system for wrists (FIG. 4:1). The wrist fins (FIG. 4:4) are curved to follow the curvature of the wrist (FIG. 4:2) and are mounted on the wrist glove (FIG. 4:3) that leaves fingers uncovered to allow underwater activities requiring fine motor skills. In the variant of the design depicted in FIG. 4 the maximum rotation of the fins is limited by the external stop (FIG. 4:5).

Claims

1. A swimming fin system, comprised of a swimming shoe, and a support frame for the attachment of an assembly of fins/stops above the arch of the foot. The system allows for a manner of swimming that is more suitable for human anatomy, and therefore more efficient. As opposed to movements imitating the undulating fish mode of swimming, collapsible fins also allow for direct backward thrust.

2. The angle of attack, geometry, curvature, and size of the fins may vary depending on the degree of proficiency, comfort, and purpose. Larger fins can be accommodated by suitable modifications of the overall design including (but not limited to) thicker soles, higher positioning of the support frame, additional prongs in the support frame, and additional fin stops or hinges for limiting the range of fins' motion.

3. The support frame can be either integrated with the swimming shoe or made attachable with straps as a separate unit. The design of the support frame may vary depending on aesthetic considerations. It may have, for example, 2, 3 or more prongs, or a solid/perforated surface design, and it can be manufactured from a range of suitable materials including (but not limited to) plastics, resins, or carbon fiber.

4. The required range of motion of fins (from “open” to “closed” position) can be achieved using a variety of means including but not limited to external (in relation to fins) stops, 90O or 180O stop-hinges, and internal (in relation to fins) stops. The fins' moving parts, including hinges and armature, can also be integrated within the fin. The fins may also be equipped with straps that lock fins in the collapsed position to allow easy walking on the ground.

5. In yet another embodiment, fins attached to the feet are complemented by similarly constructed wrist fins to further improve the efficiency of swimming, speed, and maneuverability.