Abstract: A unidirectional valve for a swimming fin has a valve seat configured to be integrally formed with a front portion of the fin and having a through hole defined through the front portion of the fin, multiple ribs radially extending inside the through hole from a joint of the ribs, an annular flange formed on an inner periphery defining the through hole and an opening defined in the joint of the ribs and a resilient-material-made disk detachably engaged with an underside of the flange of the valve seat to selectively seal the through hole and having a stub extending outward from the disk to correspond to the opening and a stop formed on top of the stub to detachably engage with a joint of the ribs to limit the travel of the disk. The unidirectional valve is able to assist the user to gain the necessary forward force when the user is paddling downward and reduces the water resistance when the user is paddling upward.

Abstract: A dolphin-tail style multi-purpose swim fin that connects to a flat swim fin securable to a user's foot is used to generate propulsion in the form of displaced water. When the connected dolphin-tail style swim fin flows through a path of displaced water from the flat swim fin at a proper angle of attack, it produces a lifting force that assists in swimming. The dolphin-tail style swim fin is shaped to enhance the propulsion from the flat swim fin. A swim fin assembly can be integrated with both flat and dolphin-tail style fins as one unit. The dolphin-tail style swim fin is shaped to generate lift as water flows across it and can be used directly by the hand (without a flat fin) or used with a handle that can be attached in lieu of the flat fin.

Abstract: A flexible elongate support (1) communicating a singular pliable tailfin (2) at an end is made to flap by upward and downward force from a swimmer's legs and midsection, thereby propelling the swimmer and device in a forward direction. The swimmer inserts legs into rearward lever element (3) and forward cradle (6) which adjustably communicate with elongate support (1) at locations substantially aligning with the feet and thigh areas of a swimmer longitudinally juxtaposed to the device and provide pivot locations about which the swimmer's legs use leverage to forcibly cause tailfin (2) to displace sequentially upward and downward. Flexible elongate support 1 provides a recoil restoring force when distorted from equilibrium during a stroke, which increases efficiency and assists the swimmer in causing tailfin (2) to flap in a manner similar to the action of aquatic creatures such as dolphins and whales.

Abstract: Methods are disclosed for increasing lift and decreasing drag on hydrofoils and swim fins. These methods include providing a hydrofoil with a highly swept back leading edge portion and orienting the hydrofoil at a significantly reduced angle of attack in which the reduced angle of attack occurs at an angle that is substantially transverse to the hydrofoil's direction of movement through a surrounding fluid medium. The lee surfaces of the hydrofoil is provided with a substantially unobstructed flow path as well as a separation reducing contour so as to permit lift generating attached flow conditions to form along such lee surfaces. Substantially rigid structural reinforcement is provided to prevent the hydrofoil from deforming significantly during use. Methods are disclosed for providing a hydrofoil with a substantially longitudinal recess or venting system located substantially along the center axis of the hydrofoil.

Abstract: The invention relates to a swim fin, comprising a seat for the foot, the so-called footpocket (1) and a propelling blade (102, 202), the fin being composed of at least two materials, whereof one is comparatively rigid and substantially inextensible and the other is comparatively soft, i.e. has a different rigidity and/or is extensible. According to the invention, the at least one comparatively rigid material forms a frame (4) for the blade (102, 202) and/or footpocket (1), designed to be overmolded with the part/s (101, 201, 301, 302, 402, 502, 105) made of the at least one comparatively soft material, which complete and/or connect and/or cover, at least partly, the parts of the frame (4).

Abstract: A swimming flipper includes a shoe portion and a blade portion. Two ribbings are provided along the outer lateral edges of the flipper and include substantially V-shaped carvings. The V-shaped carvings are placed at a suitable distance from the front of the blade portion, and are arranged to create two bending lines of the blade portion. Limiting elements are provided on the upper surface of the blade portion which limit the bending movement thereof.

Abstract: A swim fin is provided that is placed between a user's foot and the sole of a foot covering. The fin is generally planar and fin-shaped, having a heel end and a toe end, with opposing lateral sides extending between the toe end and the heel end. An optional tab(s) is located at one of the lateral sides and spaced distantly from the toe end, and may terminate in a enlarged terminal end that projects inwardly. A groove is formed between the tab and the heel end. Binding members, such as straps of a sandal, are inserted into the groove.

Abstract: Spear-bladed swim fins provide new means by which divers may propel themselves through the water. Spear-bladed swim fins generally provide a lower surface area to a higher perimeter edge length. By reducing the effective surface area of the swim fin, more propulsive force is delivered by the fin for each kick of the diver. Such dispersion of the diver's energy may be particularly advantageous where stationery swimming is required, as for underwater photography. Additionally, vortices generated during swim kicks may advantageously complement the operation of the swim fin. In the first embodiment, the spear blade is narrow. In a second embodiment, the spear blade is wider but has a larger channel through which water can flow to eliminate dead spots on the lee side of the fin.

Abstract: A diving flipper is provided wherein a blade 2 is attached to a body 1, which is secured to a foot, so that the position of the blade 2 can be switched between a position for use and a folded up position having the center of rotation in the base, or at the front, of the body 1. These flippers can be used for swimming in the same manner as conventional flippers when the blades are in the position for use and the user can easily climb the ladder of a boat or walk without the blades causing interference when they are switched to the folded up position.

Abstract: Spear-bladed swim fins provide new means by which divers may propel themselves through the water. Spear-bladed swim fins generally provide a lower surface area to a higher perimeter edge length. By reducing the effective surface area of the swim fin, more propulsive force is delivered by the fin for each kick of the diver. Such dispersion of the diver's energy may be particularly advantageous where stationery swimming is required, as for underwater photography. Additionally, vortices generated during swim kicks may advantageously complement the operation of the swim fin. In the first embodiment, the spear blade is narrow. In a second embodiment, the spear blade is wider but has a larger channel through which water can flow to eliminate dead spots on the lee side of the fin. Fork extension stubs present with the foot pocket of the swim fin provide an adjustable means by which the flexing, bowing, and/or geometry of the swim fin blade may be adjusted according to the preferences and/or demands of the diver.

Abstract: Methods are disclosed to design resilient hydrofoils (164) which are capable of having substantially similar large scale blade deflections under significantly varying loads. The methods permit the hydrofoil (164) to experience significantly large-scale deflections to a significantly reduced angle of attack under a relatively light load while avoiding excessive degrees of deflection under increased loading conditions. A predetermined compression range on the lee portion of said hydrofoil (164) permits the hydrofoil (164) to deflect to a predetermined reduced angle of attack with significantly low bending resistance.

Abstract: A short tapered fin, that when worn on the forward portion of the foot, acts as a lever to the foot with the fulcrum of that lever being on the underside of the foot. The effect of this lever action stretches the arch of the foot on every downward kick. The rigidity of the fin is also adjustable to the particular swimmer by varying the taper of the fin. The short tapered swim fin functions as a stretching device to stretch and increase the arch of the foot, and as a training device to strengthen the leg muscles that are used with the motions of flutter kick. This invention is a training swim fin that when used over time will improve a swimmer's performance for competitive swimming without fins.

Abstract: A back strap (1) for diving and swimming articles such as flippers (F), masks and goggles, is formed by two distinct and separate strap sections (1a, 1b) each of which is connected at one end (7) to a respective attachment member (3) having adjustment means (9) to vary the length of the strap (1). The two strap sections (1a, 1b) can be mutually connected and disconnected through a single buckle (2) having snap-fit lock and quick-release unlock performance.

Abstract: The present invention comprise a swim fin having an internal propulsion system, wherein the fin is secured to the wearer by a boot configured to surround the foot and ankle of the wearer resisting flexure of the ankle, the fin is integrally molded to the boot and comprises an integral, longitudinally extending tubular passageway having an inlet adjacent about the toe end of the boot and an outlet arranged at about the remote end of the fin, and the tubular passageway contains a motor driven shaft having a propeller arranged to rotate and forcibly push fluid entering the inlet of the passageway through the outlet thereof.

Abstract: A swim fin has articulating wing members articulated by means of clock washers or the like with respect to a foot pocket to provide, among other things, adjustment of pitch and tension of such wing members or other fin blade. A swim fin with articulating wing members may have a foot pocket with a forked end. Articulating wing members may then be attached to the fork stubs, there being right and left articulating wing members. Clock washers or the like may serve to provide stable and adjustable means by which the disposition of the individual articulating wing members may be selectably disposed with respect to the foot pocket. Each of the articulating wing members extends away from the foot pocket, there possibly being a gap separating the individual articulating wing members. The ends of the wing members may be flared outwardly. The outermost side of the articulating wing members may also be flared upwardly. The wing members may provide more efficient propulsion for both short bursts and long range swimming.

Abstract: A swim fin having articulating wing members articulated by means of clock washers or the like with respect to a foot pocket to provide, among other things, adjustment of pitch and tension of such wing members or other fin blade. A swim fin with articulating wing members may have a foot pocket with a forked end. Articulating wing members may then be attached to the fork stubs, there being right and left articulating wing members. Clock washers or the like may serve to provide stable and adjustable means by which the disposition of the individual articulating wing members may be selectably disposed with respect to the foot pocket. The wing members may provide more efficient propulsion for both short bursts and long range swimming. The swim fin of the present invention allows the swim kick to concentrate its energy in a more propulsive direction. An alternative embodiment of the present invention has individual webbed rails generally connected at their common base, but may be separated, or split, near their end.

Abstract: Swimming flipper consisting of a footwear equipped with a sole, and of a blade placed in front of said sole; in said flipper the sole and the blade are secured one to the other by connecting means allowing said blade to be removed from said sole and to be replaced with a similar blade or with any other type of blade.

Abstract: Methods are disclosed for increasing lift and decreasing turbulence and drag on hydrofoils and swim fins. Fins are disclosed having at least one pivoting blade region connected to the swim fin with a flexible joint element made from reduced blade thickness, blade cutout regions, and injection molding of the flexible material of the foot pocket. Methods are also provided for limiting the deflections of at least one pivoting blade region with a movable blade limiting member connected to both the pivoting blade region and a blade limiting load bearing member with a chemical bond created during molding. Methods are disclosed for orienting at least one pivoting blade region at a reduced angle of attack sufficient for increased efficiency and reduced effort. Injection molding assembly methods with chemical bonds and mechanical bonds are provided. Fins having transverse flexible elements, transverse recesses, longitudinal recesses and venting systems are also disclosed.

Abstract: This invention relates to a non-mold method of forming articles and to the articles themselves wherein various configured articles may be fashioned with conformable material which may be easily fabricated as by sewing, or heat, or sonic welding to form the basic shape of or modular elements of a completed article, and wherein a thermal setting, flowable polymer or the like is introduced into the space between layers of the conformable material to thereby form the completed article or modular element.

Abstract: Swim gear including a headpiece which covers the forward portion of the wearer's head and supports a pair of spaced lenses therein. A tailpiece which extends rearwardly from the forward portion of the wearer's head and terminates atop the wearer's head. An elastic band member is secured to the tailpiece and extends downwardly across the back of the wearer's head for secured relation with a connector member which is slidably carried on a head-encircling band. The head-encircling band extends around the wearer's head and has its ends secured to the headpiece adjacent each lens. The upper portion of the headpiece includes a surface for support of an appendage thereon. As a novelty feature, the appendage may be configured in the shape of the dorsal fin of a shark. Other configurations may be provided on the appendage, if desired.

Abstract: A diving fin and fin system for use with diving boots having a simplified attachment and quick release means wherein the diver can step in and out of the fins without having to stoop or bend. The principal advantage of this invention being its hands free operation and safety aspect.

Abstract: Swimming flipper consisting of a footwear or shoe provided with a sole equipped on its front and sides with at least two protruding elements, and a blade connected to said sole; said flipper further comprising at least an extensible element substantially transversal to the blade, laterally connected to the protruding elements and centrally to the flipper surface in an area between said protruding elements.

Abstract: Footwear, such as a swimming fin, is described with a mechanical clamp for fastening to a user's foot, the mechanical clamp being operable between a fastening position and a release position by the user's other foot.

Abstract: This invention relates to a non-mold method of forming articles and to the articles themselves wherein various configured articles may be fashioned with conformable material which may be easily fabricated as by sewing, or heat, or sonic welding to form the basic shape of or modular elements of a completed article, and wherein a thermal setting, flowable polymer or the like is introduced into the space between layers of the conformable material to thereby form the completed article or modular element.

Abstract: Swimming flipper consisting of a footwear or shoe provided with a sole equipped on its front and sides with at least two protruding elements, and a blade connected to said sole; said flipper further comprising at least an extensible element substantially transversal to the blade, laterally connected to the protruding elements and centrally to the flipper surface in an area between said protruding elements.

Abstract: Swimming flipper consisting of a footwear equipped with a sole, and of a blade placed in front of said sole; in said flipper the sole and the blade are secured one to the other by connecting means allowing said blade to be removed from said sole and to be replaced with a similar blade or with any other type of blade.

Abstract: A short motion swim fin used as training device for the improvement of the fast flutter kick motions of speed swimming and as such uses a flat flexible plate which is rigid across its base, and inner rubber sheath surrounding the plate and an outer sheath which varies in length depending upon the rigidity desired by thereby varying a projecting portion of the plate which contact the water. The plate functions as a lever on the underside of the foot to stretch the arch of the foot on every downward kick, as well as to strengthen the fast twitch leg muscles associated with a strong flutter kick.

Abstract: Swim fins includes an instep of a foot pocket which is provided with a plurality of ribs extending forward from the vicinity of an opening for foot insertion and grooves each defined between each pair of the adjacent ribs and extending forward. The instep is thinner along the grooves than along the ribs.

Abstract: A fin is formed of a foot pocket that has a slit extended from one side to another side of the foot pocket along a joint of the foot pocket and a blade of the fin, so that a front part of the foot pocket forms a movable protective flap. The movable protective flap allows a diver to easily push it open with toes and to exert strength via instep against the foot pocket during kicking water. The movable protective flap provides sufficient space for toes to move in the foot pocket without being compressed while protects the diver's foot against rocks, coral reefs and the like and therefore allows the diver to kick water more powerfully. The movable protective flap also eliminates hard and sharp edge of the foot pocket to protect the diver's foot against cut, bruised or swollen instep that is in contact with the foot pocket.

Abstract: Swim Fin with a flexible shoe portion, a pair of rotatable hinge members located on opposite sides of the shoe portion, a snap in receptacle located at the end of each the hinge portion, a rigid flat plate located at the sole of the shoe portion, extending beyond the shoe portion by approximately one inch, a pair of vertically oriented brackets each having outwardly protruding, horizontally placed tabs, a strap extending from one the tab to the other said tab, a rigid inverted U shaped member enclosing the forward most portion of said shoe portion, said rigid U shaped member having a slot in each of the side walls and one centrally located slot in the central wall to accept said strap, and a fin having a flat flipper portion and a pair of integral arms extending from said flipper portion that terminate in a male snap that communicates with said female snap located in said shoe portion.

Abstract: An adjusting strap structure for one of a pair of swim fins includes an elongated adjusting strap having two sides each having two distal ends, two first snapping members each mounted on a respective one of the two distal ends of one of the two sides of the adjusting strap, and at least one second snapping member mounted on the one side of the adjusting strap and located between the two first snapping members for detachably engaging with the two first snapping members. Each of the two distal ends of the adjusting strap extends through a respective one of the two side walls of the foot pocket, and then each of the two first snapping members are detachably engaged with the at least one second snapping member.

Abstract: This invention relates to a non-mold method of forming articles and to the articles themselves wherein various configured articles may be fashioned with conformable material which may be easily fabricated as by sewing, or heat, or sonic welding to form the basic shape of or modular elements of a completed article, and wherein a thermal setting, flowable polymer or the like is introduced into the space between layers of the conformable material to thereby form the completed article or modular element.

Abstract: A heel strap for an open heel swim fin is designed to securely hold the user's foot in the swim fin, yet minimize ankle and foot movement within the heel strap. The heel strap comprises a heel pocket and a set of straps. The heel pocket is shaped to substantially cover the bottom of the heel and to cover all sides of the heel. The straps extend from the heel pocket. They are dimensioned and configured to adjustably attach to the swim fin.

Abstract: A swim fin having a foot section with a foot cavity, a soft rubber foot pocket, and a blade section composed of blended cured layers of rubber sheet materials of selected durometer hardness. The swim fin is prepared by placing layers of sheet materials of different durometer hardness about a foot last and compression and heat molding the layers to form a molded, multiple layered, integral swim fin of selected durometer hardness.

Abstract: A swimming auxiliary device includes an attaching member an attaching member mounted to the swimmer's calf or forearm, and a connecting device connected to the attaching member so as to pivotally connect a web member to the attaching member. A pulling device is connected between the web member and the attaching member to pull the web member toward the attaching member. When the swimmer pushes the water, the water flows between the web and the attaching member so that the web member is pivoted away from the by the water. The web member is then pulled by the pulling device to return its original position again when the water flows away from the web member.

Abstract: A swim fin structured to be removably mounted on the foot of a swimmer, wherein the swim fin is intended to be used in pairs in the conventional fashion. A foot attachment portion, is secured to a fin portion, which includes a substantially elongated, at least partially triangular configuration including a periphery defined by a leading edge and a trailing edge. The fin portion also comprises two correspondingly dimensioned and configured flukes, each of which are disposed and structured to define a different one-half of the fin portion and which include two leading edge segments, collectively defining the leading edge of the fin portion and each being substantially transversely oriented to extend laterally outward from opposite sides of the attachment portion.

Abstract: A dive boot for wearing with swim fins and having a felt sole to prevent slipping on underwater objects when entering the water without the fin.

Abstract: A swimming fin comprising a blade (1) in a relatively stiff material extending from a shoe (7) of incomplete development at the rear in a relatively soft material and a strap (6) of adjustable length connected to the shoe for wrapping at the rear the foot of the swimmer. From the rear side of the blade there extends a concave sole (2), the shoe (7) being connected to the top face thereof, and to the sides thereof flaps (4) extend to which the ends of the strap (6) are connected. The swimming fin further comprises a longitudinal strip (11), in a material of intermediate stiffness between that of the blade and that of the shoe, extending along the top face of the blade (1) and above the shoe (7) to connect the blade and the shoe therebetween.

Abstract: A swimming fin includes a blade and a foot pocket, the blade including a relatively long first blade and a short second blade. The second blade underlies a bottom surface of the first blade and has transversely opposite side edge regions longitudinally extending inside transversely opposite side edges of the first blade and an intermediate region extending between the side edge regions and having its front end curved toward the foot pocket. The swimming fin thus formed can strengthen a thrust obtained by down-kicking movement of the swimming fin to thereby facilitate the up-kicking movement of the swimming fin.

Abstract: An amphibious shoe-like structure for swimming and walking having a shoe-like structure for receiving a foot and a fin structure that provides a fin blade surface that expands in the swimming mode and collapses in the walking mode to rest adjacent to the wearer's instep. The fin structure comprises a plurality of fin arms pivotally connected to the shoe-like structure for rotating the fin arms outwardly in the swimming mode position and for rotating the fin arms inwardly towards the instep of the wearer for a walking mode position. The fin arms diverge relative to one another when rotating outwardly and converge towards one another when rotating inwardly to rest adjacent to the wearer's instep. The fin structure further comprises a flexible web member that engages with the fins arms and is of the configuration and size to accomodate the area generated by the expanding and diverging side fin arms.

Abstract: A swim fin molded from flexible material such as rubber or plastics, having a foot pocket and a blade formed integral with the foot pocket, wherein the foot pocket has a sloping upper face and a slopping sole respectively sloping from the heel thereof toward the blade; the blade forwardly extends from front and two opposite lateral sides of the foot pocket and terminates in a forked end, having a thin middle portion, two thick side portions at two opposite lateral sides of the thin middle portion, two side rails respectively formed integral with the thick side portions at an outer side, and a plurality of ribs respectively formed at top and bottom side walls thereof.

Abstract: Methods are disclosed for increasing lift and decreasing drag on hydrofoils and swim fins. These methods include providing a hydrofoil with a highly swept back leading edge portion and orienting the hydrofoil at a significantly reduced angle of attack in which the reduced angle of attack occurs at an angle that is substantially transverse to the hydrofoil's direction of movement through a surrounding fluid medium. The lee surfaces of the hydrofoil is provided with a substantially unobstructed flow path as well as a separation reducing contour so as to permit lift generating attached flow conditions to form along such lee surfaces. Substantially rigid structural reinforcement is provided to prevent the hydrofoil from deforming significantly during use. Methods are disclosed for providing a hydrofoil with a substantially longitudinal recess or venting system located substantially along the center axis of the hydrofoil.

Abstract: An apparatus for aid in swimming is described as including a foot receiving portion that is pivotally attached about an axis to a fin portion. A latch mechanism is attached to the fin portion that cooperates with a tapered nose protrusion that is attached to the front of the foot portion. A pair of forward stops are provided in the foot portion which cooperate with a pair of recesses that are formed in the fin portion which together limit the pivotal motion of the fin portion in a first direction until a first position is attained. The tapered nose protrusion cooperates with the latch mechanism in the first position to secure the fin portion in the first position. The latch mechanism includes a release to allow for the manual disengagement of the latch mechanism from the foot portion which, in turn, allows the fin portion to pivot in a second direction that is opposite the first direction until a second position is attained that is disposed approximately opposite the first position.

Abstract: Swimming flipper consisting of: a shoe made of a relatively soft material and equipped with a sole made of a stiffer material, said shoe being laterally and frontally provided with at least two protruding elements, and a blade whose base is hinged to the sole of the shoe in an area between said protruding elements by means of two extensible elements, said protruding elements being suitable to hit against the upper surface of the blade.

Abstract: A short motion swim fin used as a training device for the improvement of the fast flutter kick motions of speed swimming, and as such uses a short, rigid frame, that is worn on the underside of the forward portion of the foot where it functions as a lever to stretch the arch of the entire foot on every downward kick, as well as to strengthen the fast twitch leg muscles associated with a strong flutter kick.

Abstract: A diving fin comprises a boot section and a fin section as separate parts which are held in an assembly by a supportive or hinge structure incorporated in the forefront of the boot section and a rear edge of the fin section. The hinge structure comprises an axle or shaft within axially aligned cylindrical sleeves with the shaft coupled to the fin section so that raising or lowering of the fin relative to the boot section is performed by manual manipulation of the fin section. A latch is incorporated in the hinge for detachably securing the fin both in a raised position relative to the boot section and in a lowered position projecting forwardly from the boot section. The latch comprises a fixed radial projection on the shaft engageable with slits formed in one of the sleeves. The slits comprise a circumferentially extending portion that at opposite ends has arcuately spaced apart axially oriented latch slit portions defining the two latched positions of the fin.

Abstract: A hydrotherapeutic device for the ankle includes a shoe and a plurality of fins for resisting movement of the foot relative to the ankle. The fins are of substantially equal size and shape and arranged to provide substantially equal resistance to opposite flexion of the foot and opposite turning of the foot when submerged. A set of devices may be provided, with the devices being similar in construction but providing different levels of resistance to foot movement.

Abstract: Methods are disclosed to design resilient hydrofoils (164) which are capable of having substantially similar large scale blade deflections under significantly varying loads. The methods permit the hydrofoil (164) to experience significantly large-scale deflections to a significantly reduced angle of attack under a relatively light load while avoiding excessive degrees of deflection under increased loading conditions. A predetermined compression range on the lee portion of said hydrofoil (164) permits the hydrofoil (164) to deflect to a predetermined reduced angle of attack with significantly low bending resistance.

Abstract: A swim fin for each foot or a monofin for both feet of a swimmer has an elastic flapping foil that bends away from the ball of the foot on the kicking stroke in which the instep is advanced first, and that is forced against the sole of the of the foot on the opposite stroke. this greatly enhances the efficiency of the kicking action. The free edge of the flapping foil may be curled upward to further enhance the flapping action.

Abstract: The float tube paddle fin 1 includes a web 2 which has two edge-supporting rib sleeves 3 and a central fold-supporting rib sleeve 4, encapsulating ribs 5. There is an arch strap 6 sewn onto the width of the leading edge of web 2, with free ends extending outward from web 2. Attached at the juncture of the leading edge of the web 2 and the free ends of arch strap 6 is ankle strap 7 which has an adjustment buckle 7 at one free end. Also attached to outer tube sleeves 3, at intermediate points 9, is a heel strap 10, which has an adjustment buckle 8 at one free end. The trailing edge of web 2 is hemmed to seal the supporting rib sleeves 3 and 4. Ankle strap 7 and heel strap 10 bridge the web 2, and to support the web 2 so as to fit snugly against the arch of the foot of the floatstrider, and to trail easily through the water in a "V," like closed butterfly wings, as the foot strides forward, on dry land, on river bottom, or through deep water.