Patent ID: 11944873
Assignee: NATURE'S WING FIN DESIGN, LLC
Field: Furniture, games (Other fields)
Classification: CPC A | IPC A

Claim 21:
22. A method for providing a swim fin, said method comprising:
(a) providing a foot attachment member and a blade member in front of said foot attachment member, said blade member having a longitudinal alignment relative to said foot attachment member, said blade member having opposing surfaces, blade member outer side edges and a blade member transverse dimension between said blade member outer side edges, two sideways spaced apart elongated rib members that are connected to said blade member adjacent to said blade member outer side edges, said elongated rib members each having a rib upper edge portion and a rib lower edge portion with a vertical rib dimension between said rib upper edge portion and said rib lower edge portion and a rib vertical midpoint that is midway between said rib upper edge portion and said rib lower edge portion, a rib member midpoint transverse plane of reference that extends in a transverse direction between said rib vertical midpoints of said two sideways spaced apart elongated rib members, a root portion adjacent to said foot attachment member and a free end portion spaced from said root portion and said foot attachment member, a blade member length between said root portion and said free end portion, a longitudinal midpoint between said root portion and said free end portion, a three quarter position between said root portion and said midpoint, a one quarter position between said longitudinal midpoint and said free end portion, a first half portion between said root portion and said longitudinal midpoint, a second half portion between said longitudinal midpoint and said free end portion, a three quarter portion between said three quarter position and said free end portion, and a one quarter portion that is between said one quarter position and said free end portion, said blade member having a blade member longitudinal center axis midway between said outer side edges;
(b) providing said blade member with at least one pivoting blade region connected to said swim fin in a manner that permits said at least one pivoting blade region to experience pivotal motion to a lengthwise reduced angle of attack of at least 10 degrees during use around a transverse pivotal axis that is located between said foot attachment member and said one quarter position during at least one kicking stroke direction in a reciprocating kicking stroke cycle that uses a cruising speed kicking stroke force used to achieve a cruising speed while swimming;
(c) providing at least one of said opposing surfaces along said pivoting blade portion with at least one flexible blade portion made with a significantly flexible thermoplastic material that is disposed in said blade member in an area between said blade member outer side edges;
(d) providing at least one of said opposing surfaces along said pivoting blade portion with at least one harder portion made with a significantly harder thermoplastic material that is significantly harder than said flexible thermoplastic material, said significantly flexible thermoplastic material being connected to said significantly harder thermoplastic material with a thermal-chemical bond created during at least one phase of an injection molding process;
(e) arranging at least one of said opposing surfaces of said blade member within said pivoting blade portion to form an orthogonally spaced resting state transversely concave surface that is orthogonally spaced away from said rib member midpoint transverse plane of reference to an orthogonally spaced resting state position when said swim fin is in a motionless state of rest so as to create an orthogonally spaced resting state scoop region having an orthogonally spaced resting state scoop volume that exists between said orthogonally spaced resting state transversely concave surface and said rib member midpoint transverse plane of reference when said swim fin is in said motionless state of rest wherein said orthogonally spaced resting state scoop volume has an orthogonally spaced resting state transverse cross sectional shape having an orthogonally spaced resting state scoop transverse dimension that is at least 40% of said blade member transverse dimension along a majority of said blade member length, said orthogonally spaced resting state scoop volume having an orthogonally spaced resting state vertical dimension between at least one orthogonally spaced portion of said orthogonally spaced resting state transversely concave surface and said rib member midpoint transverse plane of reference that is at least 10% of said blade member transverse dimension along at least 30% of said blade member length;
(f) providing said swim fin with a biasing force arranged to urge said at least one orthogonally biased portion of said orthogonally spaced concave surface in a first orthogonal direction away from said rib member midpoint transverse plane of reference and toward said at least one orthogonally spaced position at said orthogonally spaced resting state vertical dimension of at least 10% of said blade member transverse dimension when said swim fin is in said motionless state of rest; and
(g) arranging said biasing force to permit said orthogonally spaced resting state vertical dimension to be to be substantially maintained along a significant portion of said orthogonally spaced resting state transversely concave surface under the exertion of water pressure created when said orthogonally spaced resting state transversely concave surface is the attacking surface through the surrounding water while using a maneuvering kicking force that is used to maneuver aggressively while swimming.