Abstract: A swim fin comprises a foot portio and a web portion. The foot portion has a shoe for receiving the foot of a wearer and has a plurality of openings in a toe end of the foot portion. The web portion extends from the foot portion and has a first end, a second end, a plurality of support members having web material associated therewith, and a plurality of bosses positioned adjacent the first end connected with the plurality of openings. In an embodiment of the swim fin, a toe end of the foot portion is curved relative to an imaginary plane extending along a lower surface of the foot portion and has the plurality of openings along a surface of the toe end.

Abstract: A swim fin comprises a symmetrical fin blade. The symmetrical fin blade has a symmetrical foot pocket receiving portion, a tip portion, a blade deck, and side ribs extending from the symmetrical foot pocket receiving portion to the tip portion along side portions of the blade deck. The symmetrical foot pocket receiving portion has a support portion extending generally parallel to the blade deck. A symmetrical fabric foot pocket is joined to an upper surface of the symmetrical fin blade at the symmetrical foot pocket receiving portion. A symmetrical sole is joined to a lower surface of the symmetrical fin blade at the symmetrical foot pocket receiving portion. The symmetrical sole has a base portion extending generally parallel to the blade deck.

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 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 has the general shape of a porpoise tail and provides foot pockets adapted for fitting a variety of foot shapes and configurations.

Abstract: A swim fin and a method providing thrust from a kick by a swimmer are disclosed. The swim fin includes a swim fin for use by a swimmer comprising a foot pocket adapted to receive a foot of the swimmer; a blade extending from the foot pocket; a biasing system configured to allow the blade to bend within a narrow range of angles of attack under a wide range of loads. The method comprises providing a swim fin comprising a foot pocket, a blade, and one or more non-linear ribs that extend generally perpendicular to the blade. The method also comprises bending the blade relative to the foot pocket about an axis and controlling the bending of the blade by providing varying resistance by the non-linear ribs.

Abstract: Designs and methods are disclosed for permitting permit scooped shaped swim fin blades (184) to flex around a transverse axis to a significantly reduced angle of attack while reducing or preventing the scooped blade portion (254) from collapsing or buckling under the longitudinal compression forces (222) exerted on the scooped portion during a large scale blade deflection (212) by strategically alleviating or controlling such compression forces (222). Method are also disclosed for increasing flow capacity, effective scoop length, scoop depth over a greater length of the blade, reducing blade resistance to large scale deflections, reducing bending resistance within scooped blade portions (254) that are experiencing high levels of blade deflection. Methods are also provided for reducing lost motion and increasing propulsion during the inversion phase of a reciprocating kicking stroke cycle while also increasing the formation of a scooped blade region (254) during the inversion phase of the stroke cycle.

Abstract: A swimming fin includes a foot pack and a blade. The foot pack has a space therein for being inserted with a sole of a wearer. The blade extends from the foot pack with a flat shape. It is characterized in that a root, which is disposed at an intersection of the foot pack and the blade, is formed by way of alternate arrangement of at lest a hard coil and at least a soft coil.

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 pivotal connection 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 expandable blade limiting member connected to both the pivoting blade region and a less flexible region with a chemical bond created during injection 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 flexible portions and venting systems are also disclosed.

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 swimming flipper comprising a blade (1) made of relatively rigid material, a shoe (2) made of relatively yielding material and at least a pair of lateral ribs (3) extending along the edges of the blade. On the blade there are provided at least two longitudinal slots (9) arranged symmetrically with respect to the longitudinal axis of the flipper and two openings (11) extending diagonally from the shoe towards the lateral edges of the blade. The slots and the openings are filled with a relatively yielding material in the form of flattened ribs (12, 13).

Abstract: A universal foot fin is disclosed for use with float tubes and pontoon boats which can be selectively adapted to propel either forward or backward in the water, while simultaneously allowing the user to walk forward in either adaptation without removing the fin assembly. The fin assembly is described as being either (in simplest form) a separate FIN member to be attached to mounting fixtures which can be permanently affixed to or molded integral on wading boots, or as a complete assembly including a base member to be secured to wading boots by an releasable binding mechanism In use the fin member pivotally retracts in an upward position for walking.

Abstract: Disclosed herein is a training fin for assisting a wide variety of swimmers to gain a superior cardiovascular workout with minimal risk of injury. The fin has a proximal end and a distal end. Additionally, the fin has a dorsal section and a plantar section and defines an opening for insertion of a user's foot adjacent the proximal end. The dorsal section has proximal and distal ends aligned with the proximal and distal ends of the fin. The dorsal section is solid from the proximal to distal ends. The dorsal section has side sections. The plantar section has proximal and distal ends aligned with the proximal and distal ends of the fin and dorsal section. The dorsal and plantar sections are joined, at least, at the proximal and side sections. The dorsal surface includes a fluid separator for increasing hydrodynamic design and function. In an exemplary embodiment, the fin defines a boot, made from pliable material. The pliable material being of varying thicknesses. The boot has a foot pocket and a blade portion.

Abstract: The present invention relates to a scuba diving fin. The scuba diving fin utilizes adjustment mechanisms for the fin blade to be rotatably adjusted and locked in a first position that is in the same plane as the diver's leg and, alternatively, adjusted and locked in a second position behind the diver's calf. The present invention also utilizes a ski boot-type rigid outer shell, including the ski-boot style of clamping device used to close the boot around the diver's lower calf and ankle area. The present invention further utilizes a diver's neoprene bootie attached to the rigid outer shell to provide for a flexible lower boot portion. The fin blade first position is for diving and the second position is for walking or climbing steps.

Abstract: A swim fin and a method providing thrust from a kick by a swimmer are disclosed. The swim fin includes a swim fin for use by a swimmer comprising a foot pocket adapted to receive a foot of the swimmer; a blade extending from the foot pocket; a biasing system configured to allow the blade to bend within a narrow range of angles of attack under a wide range of loads. The method comprises providing a swim fin comprising a foot pocket, a blade, and one or more non-linear ribs that extend generally perpendicular to the blade. The method also comprises bending the blade relative to the foot pocket about an axis and controlling the bending of the blade by providing varying resistance by the non-linear ribs.

Abstract: With the development of the universal swim fin replacement strap swimmers will be able to carry inexpensive, colorful, replacement straps with them whether they came on the swim fins or not, so that in the event a buckle or strap breaks or is lost, the swimming activity is not spoiled by not being able to use the swim fins. These unique heel straps will not be encumbered with heavy adjusting buckles or heel supports, but will incorporate a novel method of length adjustment using the existing knobs located on the sides of the swim fins and a plurality of orifices along the sides from the heal area to each distal end of the strap. Pull tabs or pull rings will aide in the mounting of the universal replacement swim fin strap to the swim fins and to putting the swim fins on the foot. Additional embodiments of this invention endeavor to accomplish the same goals using similar means of attachment while staying within the scope of this patent.

Abstract: An aquatic fin for propulsion of a watercraft including a foot securing section and a blade section. The blade section having a top surface forming a concavity and a bottom surface forming a convexity. The blade section and foot section are joined by side walls and struts which define channels for directing water around the convexity in order to lessen the resistance of the fin moving downwardly and rearwardly through the water and with the upwardly and forwardly movement of the fin the concavity increases the resistance through the water, thereby propelling the watercraft away from the direction the user is facing.

Abstract: A method of modifying operational characteristics of a swim fin makes existing fins adaptable to different users and/or operational needs. An existing swim fin having a blade portion extending from a body portion is placed on a flat work surface. The blade portion is made from a rubber-like material, and a template is laid on it. The outline of the template is traced onto the blade portion to define shape lines on it. The rubber-like material is removed from within the shape lines on the blade portion of the swim fin. The shape lines and the removed rubber-like material extend from a trailing edge of the blade portion toward the body portion. The method of the invention can readily modify and/or customize the fin's contours according to the user's needs or desires concerning fit, comfort, energy use, mission requirements and/or aesthetics.

Abstract: A swim fin (10) having a foot-pocket formation (12) and a fin blade (14). The foot-pocket formation (12) defines a foot-receiving cavity in which a foot can be received. The fin blade (14) comprises a frontal blade portion (30) and a pair of side blade portions (32.1 and 32.2). The frontal blade portion extends longitudinally from a toe end of the foot-pocket formation and has a predetermined length and is spaced a predetermined height above an underside of the foot-pocket formation, which permits a wearer to walk unimpeded while wearing the swim fin. Each side blade portion includes a fixed blade section (36) and a flap formation (38) that is hingedly displaceable relative to the fixed blade section so as to change an edge profile of the fin blade, in use, for increasing the surface area of the fin blade during a propulsion stroke and decreasing the surface area thereof during a return stroke.

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: 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 pivotal connection 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 expandable blade limiting member connected to both the pivoting blade region and a less flexible region with a chemical bond created during injection 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 flexible portions and venting systems are also disclosed.

Abstract: A buoyant silicone rubber compound—and process for preparing same—is disclosed wherein hollow micro spheres are incorporated into the formulation in order to decrease the specific gravity of the compound to less than 1.0. The disclosed compound is prepared by admixing from about 85 to 99 weight percent polydimethyl siloxane with from about 1 to 15 weight percent hollow micro spheres. The micro spheres are selected to have a mean particle diameter of from about 10 to 500 microns. Aquatic gear comprised of the afore-mentioned buoyant silicone rubber exhibiting positive buoyancy/flotation such as ear plugs, swim goggles, dive masks, fins and sun glasses are also disclosed.

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: An enhanced swim fin is provided comprising a flipper blade having an increased effective surface area during movement in a first direction, and a decreased effective surface area during movement in a second direction. The swim fin preferably comprises a staged opening during movement in the first direction, in which the opened flipper blade provides increased flexion as the effective surface area is increased. The swim fin preferably comprises a staged closing during movement in the second direction, in which the opened flipper blade provides decreased flexion as the effective surface area is decreased. In some embodiments of the staged swim fin, a central hinge, generally located longitudinally along the blade on the fin, provides staged opening and flexion. Various embodiments provide fin opening and closing for either forward or backward kicks. The enhanced swim fin is typically attached to a foot, such as for performance, for training, or for physical therapy.

Abstract: A swim fin comprises a footpocket (1) and a propelling blade (2), which has a central longitudinal member (3) for supporting and stiffening the blade (2). The blade (2) has at least one pair, preferably a plurality, of ribs (5) oriented toward the free end (4) of the blade (2) and extending from the central longitudinal member (3) to the peripheral edge (4, 6) of the blade (2). The gaps (6) between the ribs (5) are at least partly closed by at least one waterproof element, so that the fin has an in-fluid behavior and an exterior aspect which is comparable to a plume or a bird's feather.

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: 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: 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 assembly of a generally T-shaped configuration including a flexible fin and an elongated foot support bar traversing and being operatively connected to the fin in a rigid securement. The fin is progressively more flexible from its forward end to its rearward end and from its upper and lower edges toward its center. A pair of foot receiving members are pivotally mounted on the foot support bar proximate its extended ends such that upon securing one's feet in the foot receiving members the fin is substantially perpendicular with respect to the wearer's feet such that upon exerting a stepping-type motion employing alternating thrusts in a prone position in a body of water, the resulting reciprocal pivotal movement of the foot support bar about its midpoint causes the vertically oriented fin to move from side-to-side and propel the wearer through the water.

Abstract: A water rehabilitation device for rehabilitating injuries and facilitating physical exercise. The water rehabilitation device includes a platform, a foot restraint attached to the platform, a first side wing pivotally attached to the platform, a second side wing pivotally attached to the platform opposite of the first side wing, a first end wing pivotally attached to the platform between the first side wing and the second side wing, and a second end wing opposite of the first end wing. During downward movement within water the wings are extended outwardly thereby creating an increased surface area effectively increasing the resistance to the downward movement. During upward movement within water the wings are folded downwardly providing an aerodynamic structure for providing reduced resistance to the upward movement.

Abstract: A diving flipper is provided wherein a blade is attached to a body 1, which is secured to a foot, so that the position of the blade can be switched between a position for use and a folded position. The folded position is attained by rotating the blade about an axis in a base, or at a front of the body. This flipper can be used for swimming in the same manner as a conventional flipper when the blade is in the position for use, and the user can easily climb a ladder of a boat or walk without the blade causing interference when the blade is switched to the folded position.

Abstract: A swim fin (10) having a foot-pocket formation (12) and a fin blade (14). The foot-pocket formation (12) defines a foot-receiving cavity in which a foot can be received. The fin blade (14) comprises a frontal blade portion (30) and a pair of side blade portions (32.1 and 32.2). The frontal blade portion extends longitudinally from a toe end of the foot-pocket formation and has a predetermined length and is spaced a predetermined height above an underside of the foot-pocket formation, which permits a wearer to walk unimpeded while wearing the swim fin. Each side blade portion includes a fixed blade section (36) and a flap formation (38) that is hingedly displaceable relative to the fixed blade section so as to change an edge profile of the fin blade, in use, for increasing the surface area of the fin blade during a propulsion stroke and decreasing the surface area thereof during a return stroke.

Abstract: The present invention relates to a scuba diving fin. The scuba diving fin utilizes adjustment mechanisms for the fin blade to be rotatably adjusted and locked in a first position that is in the same plane as the diver's leg and, alternatively, adjusted and locked in a second position behind the diver's calf. The present invention also utilizes a ski boot-type rigid outer shell, including the ski-boot style of clamping device used to close the boot around the diver's lower calf and ankle area. The present invention further utilizes a diver's neoprene bootie attached to the rigid outer shell to provide for a flexible lower boot portion. The fin blade first position is for diving and the second position is for walking or climbing steps.

Abstract: Improved diving fins in which a flexile second web surface is disposed at the approximate center portion of a longitudinal web section. As such, when the diver articulates both legs rearward and downward for aquatic kicking by posterior extension, the second web surface is automatically displaced forward by the force of water resistance and then reverts to a nearly perpendicular angle as the rigidness of the first web surface follows in coordination during the kicking sequence, with the power articulated by the legs not only capable of kicking efficiency that produces a maximum reactive force (thrust) and increases diver speed, but at the same time also allows for a reduction in kick rate and effectively delays the onset of diver fatigue.

Abstract: The invention relates to a swim fin, comprising a seat for the foot, the so-called footpocket (1) and a propelling blade (2), which has a central longitudinal member (3) for supporting and stiffening the blade (2). According to the invention, the blade (2) has at least one pair, preferably a plurality of ribs (5) oriented toward the free end (4) of the blade (2) and extending from the central longitudinal member (3) to the peripheral edge (4, 6) of the blade (2). The gaps (6) between the ribs (5) are at least partly closed by at least one waterproof membrane-like element or the like, so that the fin has an in-fluid behavior and an exterior aspect which is comparable to a plume or a bird's feather.

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: Disclosed herein is a swim fin comprising a foot attachment member, a blade region connected to the foot attachment member and forming a forward extension of the foot attachment member. The blade region has at least one side edge that may twist, and at least one longitudinal rib member secured to the blade region. The longitudinal rib member is laterally spaced from the side edge that may twist. At least one stiffening member is disposed within the blade region between the longitudinal rib member and the side edge that may twist. The stiffening member is made with a thermoplastic material secured to the blade region with a thermal-chemical bond.

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: 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: 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.

Abstract: Disclosed herein is a swim fin comprising a foot attachment member, a blade region connected to the foot attachment member and forming a forward extension of the foot attachment member. The blade region has at least one side edge that may twist, and at least one longitudinal rib member secured to the blade region. The longitudinal rib member is laterally spaced from the side edge that may twist. At least one stiffening member is disposed within the blade region between the longitudinal rib member and the side edge that may twist. The stiffening member is made with a thermoplastic material secured to the blade region with a thermal-chemical bond.

Abstract: An adjusting strap structure provided for a pair of swim fins each of which includes a foot pocket having two side walls each defining a first hole and a second hole. The adjusting strap structure includes an adjusting strap having two opposite sides and two distal ends, two first snapping members each mounted on the respective distal end of a first side of the adjusting strap, and a second snapping member mounted on the first side of the adjusting strap for detachably engaging with the two first snapping members. In such a manner, each distal end of the adjusting strap extends through a respective side wall of the foot pocket, and each first snapping member is detachably engaged with the second snapping member. In addition, each distal end of the adjusting strap in turn passes through the foot pocket into the second hole to extend outward from the second hole, and then passes through the first hole into the foot pocket to extend outward from the foot pocket.

Abstract: A flipper includes a foot pocket having a completely open front portion and a blade forward extended from two sides of the foot pocket, such that an opening is formed between the open front of the foot pocket and the blade to communicate an inner space of the foot pocket with a space behind the blade. A wearer's toes are exposed from the open front portion of the foot pocket to freely move in the opening and therefore lose an origin of force, making the wearer naturally apply forces from instep and plantar arch to move the blade downward and upward, respectively, and therefore be protected against sore and pain toe knuckles and convulsed calves, and allowed to dive for a prolonged time without consuming too much body strength.

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: An orthopedic sock system that includes a pair of identical socks each provided with pockets at various locations on the sock that are adapted to receive and hold one of a number of user inserted weight inserts. The user may add weight inserts to each of the socks as desired to achieve the desired rehabilitative or training effect.

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: A combination of strap and buckle for diving fins has a heel strap 3 and a buckle 6. The heel strap 3 has first locking teeth 21 formed thereon and a top portion 31 of the buckle 6 has its inner surface facing the heel strap 3 in the vicinity of its rear end formed in its transversely middle zone 39 with a depression hollowed out by a dimension deeper than a height of the first locking teeth 21.

Abstract: A fin has a blade provided with a hole and a one-way movable flap having a fixing edge connected to an inner margin of the blade and a moving edge overlapping an outer margin of the blade to close the hole on the blade. When a diver alternately sweeps two legs up and down under water, the movable flap on the fin worn on the upward swept leg is pushed downward by the resistance from the water to open the hole. The same resistance vanishes when the hole is opened, allowing the diver to sweep the leg upward with reduced effort. On the other hand, the flap on the fin worn on the downward swept leg is pushed upward by the resistance from the water to close the hole, allowing the diver to kick water more powerfully and advance more quickly.

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 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 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.