This disclosure relates to swim fins used for swimming underwater or at the surface.
This invention relates generally to the field of swimming and diving, and more particularly to a dolphin-tail style multi-purpose swim fin and assembly. The dolphin-tail style swim fin is multi-purpose because it can be used in conjunction with a foot swim fin to increase effectiveness and propulsion and it can also be used by the hands of the swimmer to give additional propulsion, directional control and possible defense against dangers found in open water. When used with the hand, the dolphin-tail style fin can be grasped directly by the swimmer or used with a handle suited for this purpose.
This invention is unique because it combines several ideas to produce unexpected improvements in performance, efficiency, and effectiveness and defense. In the past, most swim fins for the feet have used various shapes of xe2x80x9cwebbed feetxe2x80x9d that provide propulsion by pushing and channeling water more efficiently than our feet can. One notable exception is U.S. Pat. No. 4,934,971 which discloses a swim fin assembly including a novel aerodynamic web shape that reduces turbulence created by the swim fin and improves performance substantially. This disclosure attempts to simulate the swimming action of sea mammals but may be a limitation of those swimming actions because those animals have a complex system of muscles, ligaments and bone that control the angle of attack of the aerodynamic web shape through the water. With natural kicking motions available to the swimmer, the aerodynamic web shape does not move through a stream of water at an angle of attack that takes advantage of its aerodynamic shape.
The present invention arose from continuing efforts to improve the efficiency and operation of the swim fin variations disclosed in U.S. Pat. No. 5,906,525. U.S. Pat. No. 5,906,525 also discloses a swim fin that attempts to simulate the swimming actions of whales and fishes. Again, the lack of control of the angle of attack of the aerodynamic form flowing through the water inhibits any real production of power from the various fins disclosed in that patent.
According to the details of the dolphin-tail style swim fin embodiment disclosed and shown in the accompanying drawings, the dolphin-tail swim fin is formed as a rigid member having a substantially transverse trailing edge that is generated as a swept-back ellipse with aerodynamically shaped proportional forms as sides that slope towards the center rear portion of the form. This dolphin-tail style swim fin is connected (temporary connection or as an integrated form) to a first swim fin having a first narrow end securable to a user""s foot and a second wider end for displacing water to generate propulsion (where the dolphin-tail style swim fin is attached.) The first swim fin a semi-rigid member that allows enough bend when used to present the leading edge of the dolphin-tail style swim fin at a proper angle of attack to the flow of water produced from kicking with the first swim fin. The dolphin-tail swim fin can also be used independent of the first swim fin when used by hand. It can be grasped directly and moved through the water at the correct angle of attack, or it can be held by a handle that would attach by a similar means as the first swim fin.
An object of this invention is to provide efficient power to assist with swimming near the surface of the water or underwater using swim fins designed for the feet that enhance water flow and provide lift.
Another object of this invention is to provide a secondary source of efficient power to a swimmer with the use of swim fins for the hands that work at any speed in the water by providing lift.
Yet another object of this invention is to provide the swimmer with more control using these fins with the hands for steering and lateral locomotion.
A further object of this invention is to provide the swimmer with more control using these fins with the hands for swimming backwards effectively and efficiently even while wearing foot swim fins.
A still further object of this invention is to provide the swimmer with a defensive tool by using these fins with the hands for protection from foreign objects and predators while swimming in open water.
Other objects and advantages of the present invention will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.
In accordance with a preferred embodiment of the invention, there is a swim fin assembly having a swim fin with a narrow end securable to a user""s foot (a flat blade fin) and a second wider end for displacing water to generate propulsion and a second swim fin (a dolphin-tail style fin) connected to the second end of the flat blade fin in a path of displaced water from the flat blade fin in which the dolphin-tail style fin is shaped to enhance the propulsion generated by the flat blade fin. This assembly can be composed so that the first and second fin are integral or they can be connected with a connector, a mortise and tenon, or some other means of attachment. The dolphin-tail style fin is shaped to generate lift as water flows across the dolphin-tail style fin. This allows the dolphin-tail style fin to be used without the flat blade fin as a swimming aid for use with the hand. The flow of water over the dolphin-tail style fin is created by the hand moving the dolphin-tail style fin through the water at a proper angle of attack. In addition to creating lift, the dolphin-tail style fin also channels water to the center of the dolphin-tail style fin pulling water away from the sides where it would create vortices and drag. A separate handle can be used when connected to the attachment means found on the dolphin-tail style fin so that the hand can properly move the dolphin-tail style fin through the water to create water flow over the dolphin-tail style fin to generate lift to aid in swimming.
In accordance with one particular aspect of the present invention, a swim fin assembly includes a first swim fin having a first narrow end securable to a user""s foot and a second wider end for displacing water to generate propulsion. The assembly also includes a second swim fin connected to the second wider end of the first swim fin in a path of displaced water from the first swim fin, the second swim fin being shaped to enhance the propulsion from the first swim fin. The second swim fin may be integral with the first swim fin or may be attached to the first swim fin with a connector, such as a mortise and tenon connector. The second swim fin is preferably shaped to generate lift as water is flowed across the second swim fin, such as an airfoil-shaped cross-section. The second swim fin is also preferably shaped to channel water toward a center of the second swim fin. Still further, the second swim fin may be curved in a direction of water flow.
In accordance with another aspect of the present invention, a swim fin component attachable to an existing swim fin in a path of displaced water from the existing swim fin is shaped to enhance a propulsion effect from the existing swim fin. The swim fin component may be usable as a swimming aid in a user""s hand. In this context, the swim fin component may be attachable to a handle shaped to fit in the user""s hand.
In accordance with still another aspect of the present invention, a swim fin assembly includes propulsion structure for generating propulsion and propulsion enhancing structure cooperating with the propulsion structure for enhancing the generated propulsion.
The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.