Abstract: A composite swim fin with a cantilevered heel. The cantilevered heel acts as a structural member extending to and beneath the swimmer's heel to counteract the flexure of the swim fin blade during the most powerful downward kick, This type of loading on the heel of the foot replicates the natural loading incurred on the heel of the foot during walking and reduces uncomfortable stress concentrations that might otherwise occur upon the swimmer's foot.

Abstract: Footwear which is versatilely useful for both land and water sports is described along with a method of production. A stretchable fabric vamp is conformable around the upper arch region of a user's foot. The vamp is joined to an upper edge of an elastomeric base piece including sole and fin portions. The flexibility of the vamp provides comfort and versatility for various walking, running, surfing or swimming activities. The base piece is more rigid than the vamp. The fin is stabilized by a toe support which contains the user's toes and is part of the same unitary base piece. The rigidity of the base piece provides hardness for the sole to protect the foot from harsh ground conditions and stiffness for the fin producing desirable water resistance qualities for enhancing swim power.

Abstract: A swim fin which comprises a unitary member having a foot region, a blade gion and a device for securing the foot of a swimmer to the swim fin. The swim fin includes an expanse of water-buoyant material which provides for a swim fin which is water-buoyant as a whole. The swim fin is designed such that it may be easily applied to a user's foot and comfortably used both in and out of the water.

Abstract: A flipper-type swimming propulsion aid assembly for attachment to the feet of a swimmer to increase the swimmer's effective foot area. The swimming aid for each foot includes a collapsible frame of generally isosceles triangular configuration having side frame members of substantially equal length which are pivotally joined through a heel plate at the heel end of the frame and a foldable cross frame member joining the toe ends of the side frame members. The swimming aid also includes a fabric or plastic sheet web component which is placed over the collapsed frame assembly and thereafter the side frame members are separated with the cross frame member opened and extended. The web component is provided with mating attachment straps affixed to the toe end of said web component and positioned to be wrapped about the cross frame member to maintain such member's open and extended orientation.

Abstract: A swimming flipper has a flipper blade integral with a shoe pocket with a rear entry opening, a heel strap for retaining the swimmers's foot in the foot pocket. An ankle strap attached to the heel strap loops around the ankle of the swimmers's foot above the heel strap and prevents loss of the flipper in the event the heel strap slips from the foot. Both heel and ankle straps have hook and loop fasteners which cooperate to secure the straps around the user's heel and ankle. The heel and ankle straps constitute a unit which can be easily retrofitted as an upgrade for many existing swimming flippers having conventional heel straps.

Abstract: A swimming flipper includes a blade of fairly rigid thermoplastic material and a shoe of elastomeric material or soft thermoplastic rubber. The blade has a partially multi-layered structure including a base layer made of the fairly rigid thermoplastic material and a partial outer layer of a more resilient material which is superimposed on and connected permanently to the base layer.

Abstract: The present invention is a swim fin equipped with extendable knives which can be used by a diver to fight off an attack by a predatory underwater creature, such as a shark. The knives, when in their locked closed positions, lie in a recessed section provided in an outside edge of the swim fin. In their locked closed positions, the knives lie parallel with a bottom surface of the swim fin. When extended to their locked open positions, the knives point downward from the swim fin. The swim fin is provided with means for locking the knives in their open and closed positions, unlocking the knives from their locked open and locked closed positions, and moving the knives between their open and closed positions.

Abstract: A swim fin specifically designed for use by an amputee comprising a substantially planar, elongate flipper portion integrally formed with and extending from a receiving pocket adapted to be mounted to the end of a limb of the amputee. A pair of elongate straps are connected along a side of the receiving pocket, wherein the straps are specifically designed to wrap around the amputee's limb, being fastened by a pair of mating hook and loop pads on opposite ends of the straps, thereby effectively securing the swim fin to the amputee's limb.

Abstract: A flipper assembly comprises a rectangular, grid-shaped frame with a plurality of longitudinal strips spacedly disposed therein, a plurality of danglable leaves, and a plurality of transverse crossbars. Each of the crossbar is disposed under the frame spacedly and attached to an upper surface of a leaf respectively. Two pairs of straps are disposed at two opposite sides of the frame respectively. The total weight of the largest sized flipper assembly is only 710 grams. Another flipper assembly comprises a sandal, a rectangular frame with a plurality of longitudinal strips spacedly disposed therein, a plurality of danglable leaves, and a plurality of transverse crossbars. Each of the crossbar is disposed under the frame spacedly and attached to an upper portion of a leaf respectively. A strap is disposed on the upper surface of the sandal.

Abstract: Improved swimming efficiency and safety in a water environment is achieved with the use of retractable swim fins having a web-like member rotatably interconnected to a shoe-like member. A latch includes a latch element which secures the web-like member to the shoe-like member in a downward swimming position. The latch element is released by linear pressure from the other foot to permit the web-like member to rotate in response to a spring force to an upward walking position. A natural swimming kick returns and latches the web-like member to the swimming position.

Abstract: Disclosed herein is a training fin for swimming which includes a foot section having an enclosure for retaining a user's foot in the fin and a tail section attached to the foot section. The tail section has a surface area of approximately between 0.25 and 1.0 times the surface area of the foot section.

Abstract: The invention relates to an improved swim fin retainer that provides a locking mechanism for attaching the fin to the user's foot. The improved swim fin retainer utilizes a latching mechanism that is in connection with a heel strap so that the swim fin can be attached and removed in one action. The provides an easy method for attaching and detaching swim fins without having to use one's hands.

Abstract: An amphibious shoe, which includes a show body having set therein a fastening plate at its front end for the connection thereto of a diving flipper. The diving flipper includes therein an unitary connecting rubber plate portion having a plurality of through-holes with a plurality of screws screwed upward to fasten in or screwed downward to disconnect from a plurality of internally threaded hollow stubs which extend from the fastening plate of the shoe body, so as to secure the diving flipper to or separate it from the shoe body.

Abstract: A swim fin having a low drag profile foot pocket-beam assembly, achieved by attaching a single beam to the bottom of the foot pocket to support the rigid blade. Such construction has the added advantages of making it possible to taper the sides of the toe portion of the foot pocket to generally conform to the shape of the foot, reducing the drag profile of the foot pocket and positioning the single beam so-that it is behind the foot pocket during swimming, thereby improving swim fin efficiency.

Abstract: Improved swimming efficiency and safety in a water environment is achieved with the use of retractable swim fins having a web-like member rotatably interconnected to a shoe-like member. Latching means secure the web-like member to the shoe-like member in a downward swimming position. Releasing means permit the web-like member to rotate to an upward walking position. Pressure from a swimmer's foot returns and latches the web-like member to the downward position.

Abstract: The invention refers to a swimming flipper of the type with a "shoe" part (10) made of relatively soft material and a blade part (20), made of relatively stiffer material, suitably joined to one another and preferably formed with the first part on top of the second. According to this invention, the blade (20) has an outer sole (22) which extends right under the heel (11) of the shoe (10). Furthermore, the blade (10) is equipped with an arched strap (23) which surrounds the upper (13) of the shoe transversally (FIG. 6).

Abstract: A flipper for flipper swimming having a varying thickness blade of resin sheets of varying length stratified sheets interposed between longer resin sheets and a natural rubber shoe hot pressed to the blade.

Abstract: A flipper-type swimming propulsion aid assembly for attachment to the feet of a swimmer to increase the swimmer's effective foot area. The swimming aid for each foot includes a collapsible frame of generally isosceles triangular configuration having side frame members of substantially equal length which are pivotally joined through a heel plate at the heel end of the frame and a foldable cross frame member joining the free or toe ends of the side frame members. The swimming aid also includes a fabric or plastic sheet web component which is placed over the collapsed frame assembly and thereater the side frame members are separated with the cross frame member opened and extended.

Abstract: Disclosed herein is a training fin for swimming which includes a foot section having an enclosure for retaining a user's foot in the fin and a tail section attached to the foot section. The tail section has a surface area of approximately between 0.5 and 1.0 times the surface area of the foot section.

Abstract: A swim fin includes harness for attachment to a wearer's foot, the harness including an adjustable strap secured to the fin on opposite sides of a forward portion of the wearer's foot, the adjustable strap forming an X configuration passing over the wearer's instep and around the wearer's heel. Liner straps are arranged between forward portions of the adjustable strap and the wearer's foot while lateral straps are anchored to rearward portions of the fine and secured to opposite side portions of the adjustable strap. The fin has a generally flat configuration with one or more flanges extended beneath the wearer's foot and along forward portions of the fin for controlling the amount of bending or flexing experienced by the fin.

Abstract: A swim fin includes a shoe assembly for attachment to the individual feet of the user, an outwardly projecting rigid support frame, a pivoted web, and a strap or band for yieldably limiting the extent of pivotal movement of the web relative to the supporting frame about a transverse pivotal axis. The web has a plan configuration that includes a substantially straight transverse trailing edge and a leading edge in the shape of a swept-back ellipse. Longitudinal sections across the web have proportional sectional configurations and a constant maximum thickness to length ratio between the upper and lower web surfaces.

Abstract: A swim fin adapted to be mounted on a foot of a swimmer including a foot receiving portion having a substantially planar base section terminating at one end thereof in a heel section which extends downwardly therefrom and which terminates at the other end thereof in an open toe section and an elongated flexible fin member formed of a resilient material and which extends from the open toe section and which is integral with the substantially planar base section of the foot receiving portion wherein the elongated flexible fin member is generally trapezoidal in shape with the smaller end thereof contiguous the open toe section of the foot receiving portion and with the longest end of the elongated flexible fin member forming a deflecting end which terminates in a pair of movable tips wherein the cross-sectional shape of the elongated flexible fin member in a direction which is normal to the center line extending substantially perpendicular from the smaller end to the deflectable end which is thicker at the center

Abstract: The specification herein shows a swimmer's fin having a foot pocket and a blade portion wherein the blade portion is offset from the foot pocket to compensate for the natural supination during a flutter kick, stroke or beat, regardless of whether or not it is a backstroke, kick, or a crawl stroke kick. The fin can be molded in a symmetrical manner so that it can be interchanged between the feet and provided with an offset ankle strap in order to create a more comfortable relationship during the swimming movement. The fin also includes an improved blade end having inner and outer curves wherein the outer curve from the body is of a larger radius than the inner curve. The offset of the foot pocket from the blade can be such wherein the axis of the blade and the axis of the foot pocket intersect within the foot pocket area to provide for improved performance.

Abstract: A flipper-type swimming propulsion aid assembly for attachment to the feet of a swimmer to increase the swimmer's effective foot area. The swimming aid for each foot includes a dismantlable frame of generally isosceles triangular configuration having side frame members of substantially equal length which are pivotally joined at the heel end of the frame and at least two cross frame members of progressively greater length adapted at their ends for removable joinder to the side frames with the longest of the cross frame members joining the free ends of the side frame members. The swimming aid also includes a fabric or plastic sheet web component for the frame with the web component being of generally isosceles triangular configuration matching the configuration and size of the frame and including side loops for receiving and maintaining the side frame members and including cross loops for receiving and maintaining the cross frame members.

Abstract: The swim fin has a rigid blade that is fixedly attached to the end portions of two flexible beams which are molded to the sides of the foot pocket and project therefrom. The flexible beams project forwardly and inwardly for a short distance so as to position the flexible beams behind the toe of the foot pocket as the swim fin moves through the water during swimming. The height of the flexible beams is reduced at a position near the leading edge of the rigid blade so that most of the flexing is confined to this position. The rigid blade is hollow and the end portions of the flexible beams are enclosed in the shell of the rigid blade.

Abstract: A swim fin provided with a canal-like member for conveying and controlling the fluid flow produced during each swimming stroke. The fin comprises at least at the central portion of its blade a section which, by dynamical deformation, gives rise to a canal-like fluid flow conveying member on that side of the fin opposed to the side under active stroke. The canal-like member is inverted as soon as the swimming stroke is reversed, so as to perform its fluid flow conveying action during both swimming strokes.

Abstract: A swim fin adapted to be mounted on a foot of a swimmer including a foot receiving portion having a substantially planar base section terminating at one end thereof in a heel section which extends downwardly therefrom and which terminates at the other end thereof in an open toe section and an elongated flexible fin member formed of a resilient material and which extends from the open toe section and which is integral with the substantially planar base section of the foot receiving portion wherein the elongated flexible fin member is generally trapezoidal in shape with the smaller end thereof contiguous the open toe section of the foot receiving portion and with the longest end of the elongated flexible fin member forming a deflecting end which terminates in a pair of movable tips wherein the cross-sectional shape of the elongated flexible fin member in a direction which is normal to the center line extending substantially perpendicular from the smaller end to the deflectable end which is thicker at the center

Abstract: A swimming flipper is disclosed with two opposed rails on each side of flipper extending outwardly and at an angle to the plane of the flipper surface. The flipper surface may also be provided with a number of stepped segments such that the thickness of the flipper portion increases from the front edge of the flipper towards the toe portion.

Abstract: A heel protection device for the heel strap of a conventional swimfin is disclosed, which protects the wearer from bruising, blistering, and chafing of the foot while wearing and using the swimfin. The heel protector is made of a sheet of polymer foam material and has a body portion with a width and a length with the length being larger than the width, and tabs on opposite sides of the body, with the width of the body between them. Fasteners are provided on the tabs for fastening the protector around the heel strap of a swimfin. Also disclosed is a method for making the device and a method for using the device.

Abstract: A swim fin having an elongated flexible blade. The blade has elongated tapered sleeves to hold elongated tapered battens. The battens selectively stiffening the blade to achieve varying degrees of stiffness according to the wear's strength. Each batten has a tab to function to prevent the batten from sliding entirely within the sleeve and to function as a grip for easy removal of the batten from the sleeve. Additionally, the fin has ribs with concave outer walls which assist in the smooth flexing of the fins when used.

Abstract: A band mounting for a diving fin is provided to fix a foot on a diving fin body. The construction of the mounting enables one to draw freely on an end of the band in its fastening direction while enabling a user to firmly lock the end of the band in its loosening direction.

Abstract: A diving fin includes a heel strap coupled to opposite sides of a foot pocket wherein coupling of at least one end of the strap to at least one of the opposite sides of the foot pocket as well as adjustment of the fastening effect of the strap on the divers heel can be achieved by a buckle. The buckle comprises a first coupling member of sheath-like configuration and a second coupling member having a plug portion adapted to be releasably engaged into the first coupling member and a retaining frame movably supports therearound the strap.

Abstract: These water running fins are designed to be worn on a person's feet to enable the user to effectively run on the surface of a body of water. Primarily, the fin consists of a main body with a foot receiving member attached, and the main body is provided with forward spoke portions attached to a web portion. The structure further includes a multiple number of first fingers and second fingers pivotally attached by wires that serves as the pivots, and over upward travel of the fingers is limited by the rear portions of the fingers being rearward of the pivot points.

Abstract: A swimming aid, comprising a transverse fin attachable to the feet of a swimmer and formed of a resilient material so as to twist in swimming, is disclosed. In a preferred embodiment, the fin comprises a stiffening member, to control its shape while twisting. The fin is disclosed in combination with a unitary wet-suit.

Abstract: The blade, beams and foot pocket of the improved swim fin are all molded together in one piece of the same non-rubber thermoplastic elastomer. To provide flexibility, the part of the foot pocket that fits over the arch of the foot is formed to include a plurality of straps.

Abstract: A hydrodynamic swim fin utilizes a wing and a tail that are overlapped normally to provide a two stage propulsion system. Ribs support the wing and tail and define flow channels. These ribs are parallel to each other and to the longitudinal axis of the fin whereby the effective area through which flow proceeds is uniform throughout the length of the fin. No parts of the ribs form barriers to the leading edges of the side wing segments whereby laminar flow is achieved. The fin part is maintained essentially rigid; however, the fin part is allowed limited angular movement about a defined transverse axis to achieve proper attack angle. Since the fin part is rigid, it maintains that attack angle throughout the length of the fin part. Trailing ends of the wing are individually flexible to produce greater opening for two stage propulsion during the power downstroke, and to produce substantial closure for one stage propulsion during the upstroke.

Abstract: In the first form of the present invention, a swim fin includes a foot pocket, two flexible beams projecting forwardly therefrom, a blade attached to the forward end portions of the flexible beams and displaced from the foot pocket, the foot pocket, flexible beams and blade all being molded in one piece. A narrow rigid plate is attached to the blade and flexible beams at a point near the leading edge of the blade to connect the flexible beams to support the leading edge of the blade, and together with the part of the flexible beams attached to the blade, to provide a blade structure which is generally rigid during swimming but is flexible during walking and standing. In the second form of the present invention, the foot pocket and flexible beams are molded in one piece whereas the blade which is rigid is molded separately. The forward end portions of the flexible beams are attached to the rigid blade with fasteners.

Abstract: A swim fin including a foot pocket has a rigid blade pivotally attached to a spring-biased strut assembly, one end of which is attached to the toe of the foot pocket, the other end of which is attached to the leading edge of the rigid blade. In one form the swim fins are provided as a pair, the blade of one having its trailing edges inclined, the leading edge of the blade of the other fin having leading edges inclined to accommodate the trailing edge of the other fin. The hinge point of one fin is located farther from the toe of the foot pocket than is the case for the other fin so that the swim fins can be used without their blades striking each other. The structure requires a minimum amount of energy for blade angle reversal during swimming.

Abstract: A swim fin adapted to be used in the swimming or walking mode having a foot engaging portion adapted to be worn by a user and a two-part fin formed of an inner portion and outer portion which are connected to each other and rotatable with respect to each other using a suitable hinge assembly so that the outer portion may be folded on top of or under the foot wearing portion to facilitate walking and to enable the outer portion to be extended to facilitate swimming. Suitable locks are provided to maintain the fin portions in the extended or folded positions.

Abstract: A swim fin provided with a canal-like member for conveying and controlling the fluid flow produced during each swimming stroke. The fin comprises at least at the central portion of its blade a section which, by dynamical deformation, gives rise to a canal-like fluid flow conveying member on that side of the fin opposed to the side under active stroke. The canal-like member is inverted as soon as the swimming stroke is reversed, so as to perform its fluid flow conveying action during both swimming strokes.

Abstract: An improved hydrodynamic swim fin utilizes a wing and a tail that are overlapped normally to provide a two-stage propulsion system. Ribs support the wing and tail and define flow channels. These ribs are parallel to each other and to the longitudinal axis of the fin whereby the effective area through which flow proceeds is uniform throughout the length of the fin. No parts of the ribs form barriers to the leading edges of the side wing segments whereby laminar flow is achieved. The fin part is maintained essentially rigid; however, the fin part is allowed limited angular movement about a defined transverse axis to achieve proper attack angle. Since the fin part is rigid, it maintains that attack angle throughout the length of the fin part. Trailing ends of the wing are individually flexible to produce greater opening for two-stage propulsion during the power downstroke, and to produce substantial closure for one-stage propulsion during the upstroke.

Abstract: An improved swim fin includes a foot pocket, first and second flexible beams supported by the pocket and projecting forwardly from it, first and second struts attached securely to outer ends of the first and second flexible beams, respectively, a narrow, rigid, streamlined blade having a large span rigidly attached to outer ends of the first and second struts. The first and second flexible struts are composed of flexible plastic and have elliptical cross-sections to reduce drag and to prevent twisting. The first and second struts form legs of a U-shaped member, the bottom of which forms a cross-member maintaining spacing between the first and second flexible beams at a fixed value.

Abstract: A swim fin having a foot pocket and two flexible beams projecting directly forwardly from the sides of the toe of the foot pocket. A rigid blade is attached to the flexible beams so that a space exists between it and the foot pocket. The elements which are provided to attach the two flexible beams to the rigid blade include a pivot point for the rigid blade. The swim fin is simple in design and is designed for maximum efficiency, comfort and reliability.

Abstract: A swim fin is disclosed which comprises a foot portion, an essentially horizontal flipper and upper and lower shells coupling the foot portion and the flipper. Upper and lower channels are formed between the shells and the flipper for the flow of water therethrough. The channels initiate at water inlet apertures and terminate at water outlet apertures. The flipper extends outboardly of the channels and water outlet apertures to coact with water flowing from the outlet apertures for increased efficiency of the fin.

Abstract: The improvement provided by this invention is directed at the conventional beach-shoe and diving flipper, and according to this invention, a novel beach-shoe capable of acting as a diving flipper is provided. The web portion is extensible relative to a shoe body, the shoe can be used as a beach-shoe when a web member is received in a recess of the shoe body, and a guarding piece is placed in a cut-out made in the front end of the shoe body to admit the web member to pass through.

Abstract: Swimming apparatus for improved propulsion includes fluked foot flippers constructed to include a stiff load-bearing frame member in the leading edge of the fluke. As the flipper is pumped by the swimmer, a web secured to the frame member is caused to cup the flowing water by arching its surface. The flipper permits arching of the web and bending of the frame member both upward and downward, thereby creating a powerful stream of water propelled to the rear and resulting in a powerful propulsive forward thrust of the swimmer. The thrust is further enhanced by applying precisely formed hydrofoil cross-sectional or chordwise shaping to the fluke to accelerate the flow of water into the pocket. This flow also creates a lifting force which is in the direction of the fluke's motion and thus supports the kicking effort. In addition, spanwise hydrodynamic shaping serves to guide a greater volume of water into the pocket thereby further increasing the propulsive thrust.

Abstract: A swim fin for use by breaststroke swimmers is described. The swim fin has a shoe-like rear compartment and a closed forward extension from said compartment. The forward extension has a relatively flat bottom surface and a curved convex upper surface, so cambered that the thickness of the extension at its inner side is substantially the thickness at the outer side.