Hand paddle

Abstract

The present invention is a swim aid consisting of a paddle blade having a hand side and an opposite water side, a proximal end, a distal end opposite the proximal end and having a distal edge and opposite first and second lateral ends. Finger apertures are formed along the distal end of the blade and separated from the distal edge by a fingertip portion, the apertures being separated from each other by inter-digital portions. The paddle includes a wrist portion formed on the proximal end of the blade, the wrist portion having a wrist strap, and a palm portion formed on the blade between the apertures and the wrist portion, the palm portion forming a concave surface on the waterside of the blade. A thumb notch is formed on the first lateral end of the blade. The paddle further includes a first and second flange portion formed on the first and second lateral ends, respectively, the flange portions being swept back from the water side of the blade towards the hand side of the blade, the first flange portion extending from the notch to the wrist portion, the second flange portion extending along the second lateral end from the wrist portion to the apertures. The inter-digital portions are swept back from the waterside of the blade towards the hand side of the blade and the fingertip portion is swept forward towards the waterside of the blade relative to the inter-digital portions sufficiently to permit the users' fingers to extend fully through the apertures when the paddle is worn.

Description

FIELD OF THE INVENTION

The invention relates generally to hand paddles for swimming.

BACKGROUND OF THE INVENTION

Swimming aids such as swim fins and hand paddles are routinely used both as aids to swimming and as swim training aids. Hand paddles in particular are useful as swimming aids since they permit the user to apply greater force to their swimming strokes. Traditionally, hand paddles for use in swimming consist of a blade worn on each of the users hands. In a majority of hand paddle designs, which have been attempted, the blade consists of a flat planar member roughly in the outline of a hand and having a strap or brace on one side of the blade for accommodating the user's hand. For example, U.S. Pat. No. 894,311 to Brenton, U.S. Pat. No. 2,389,196 to Harmon, U.S. Pat. No. 2,555,969 to Holcombe, U.S. Pat. No. 3,765,042 to Montrella, U.S. Pat. No. 3,922,740 to Potter, U.S. Pat. No. 4,913,418 to Schlueter et al., U.S. Pat. No. 5,288,254 to Elson, U.S. Pat. No. 5,511,998 to Johnson, U.S. Pat. No. 5,651,710 to Rives et al., and U.S. Pat. No. 6,019,650 to Rives et al. and many others all disclose swim paddles having flat planar swim blades with one or more straps for securing the paddle to the user's hand. Other swim paddles use a flat planar blade having a plurality of apertures configured to permit the user to grasp onto the blade by passing the user's fingers through the apertures to facilitate the user's grip on the paddle. U.S. Pat. No. 2,745,119 to Whipple and U.S. Pat. No. 3,397,414 to Webb are examples of this sort of design. Yet another design for swimming hand paddles consist of a flat blade having an integral hand grip permitting the user to grip onto the paddle by grasping the hand grip. U.S. Pat. No. 4,233,925 to Proctor, U.S. Pat. No. 4,493,662 to Richmond and U.S. Pat. No. 6,398,603 to Brown are examples of this later design.

These prior art hand paddles all permit the user to apply greater force to their swimming strokes; however, they suffer from a common problem, namely flutter. As the flat planar paddle is forced through the water by the user, the paddle tends to flutter wildly causing the user to expend energy to hold his hand steady through the stroke. Furthermore, the fluttering motion experienced by these flat planar swimming paddles may cause the user to loose his or her grip on the paddle. As a result, the user must often tighten his or grip on the paddle in order to keep the paddle in control during the stroke. A tighter grip creates increased fatigue and muscle strain in the user's hand, as the user must exert additional effort into maintaining a smooth swimming stroke. Furthermore, flat planar paddle designs usually require the users hand to be held flat against the swimming paddle with the fingers outstretched. This is not a natural position since the human hand, when in a comfortable position, tends to cup. Holding the hand in a flat position with the fingers outstretched for long periods of time results in increased hand strain and hand fatigue.

Swimming paddles having concaved paddles have been attempted. These swimming paddles usually include a blade having a concave surface on one side and a hand holding aid, such as a hand strap, on the other side. U.S. Pat. No. 950,633 to Eastman, U.S. Pat. No. 2,159,972 to Larson and U.S. Pat. No. 183,045 to Dunlop and U.S. Pat. No. 5,643,027 to Evans et al. are examples of this type of design. These swim paddles consist of a flat member having a concave surface on one side and a convex surface on the opposite side, the hand strap being incorporated on the convex side. These designs have the advantage of permitting the user to grip the hand paddle in a more comfortable manner. These concave paddle designs also suffer from the problems associated with paddle flutter. Indeed, these concave designs often suffer from increased flutter due to turbulence created by the concave surface impinging on the water.

SUMMARY OF THE INVENTION

In accordance with the present invention, here is provided a hand swimming paddle which overcomes the drawbacks of the prior art such as flutter and hand strain. The improved hand paddle includes a blade having a hand side and an opposite waterside. The blade has a proximal end, a distal end opposite the proximal end and opposite first and second lateral ends. A wrist portion is formed on the proximal end of the blade, the wrist portion adapted and configured to retain a user's wrist when the paddle is worn. A finger portion is formed towards the distal end of the blade, the finger portion being adapted and configured to retain the user's fingers when the paddle is worn. First and second flange portions are formed on the first and second lateral ends, respectively, the flange portions being swept back from the water side of the blade towards the hand side of the blade, the flange portions extending from the wrist portion to the finger portion of the blade.

The invention is also directed at a method of manufacturing a swim paddle as described above by first forming a metal blade having the shape of the desired hand paddle by stamping a sheet of metal and then coating the metal blade with a plastic material.

The invention is also directed at a method manufacturing a swim paddle as described above by first extruding a high modulus thermoplastic into a foamed sheet of two to six thousands of an inch thick with a density of 6 to 15 pounds per cubic foot, then thermoforming the sheet into a slightly concave geometric shape, then cooling and stress-stabilizing the stress-stabilized sheet and then cutting out the paddle in a cutter.

With the foregoing in view, and other advantages as will become apparent to those skilled in the art to which this invention relates as this specification proceeds, the invention is herein described by reference to the accompanying drawings forming a part hereof, which includes a description of the preferred typical embodiment of the principles of the present invention.

DESCRIPTION OF THE DRAWINGS

FIG. 1. is a top view of a right hand swim paddle made in accordance with the invention.

FIG. 2. is a sectional view of the swim paddle shown in FIG. 1 taken along line A-A.

FIG. 3. is a sectional view of the swim paddle shown in FIG. 2 taken along line B-B.

FIG. 4. is a top view of a right hand swim paddle made in accordance with the invention being worn on a user's hand.

FIG. 5 is a sectional view of the swim paddle shown in FIG. 4 taken along line C-C.

FIG. 6 is a bottom view of right hand swim paddle made in accordance with the invention being worn on a user's hand.

FIG. 7 is a bottom view of the right hand swim paddle made in accordance with the invention being worn on a user's hand with the user's fingers being extended.

In the drawings like characters of reference indicate corresponding parts in the different figures.

DETAILED DESCRIPTION OF THE INVENTION

Referring firstly to FIG. 1, a swim paddle made in accordance with the invention for use on the right hand is shown generally as item 10. It will be appreciated that the present invention is directed towards swim paddles for use with both the right and left hands. A swim paddle made in accordance with the present invention for use in the left hand would be a mirror copy of paddle 10 and would have all of the features of the paddle shown in FIG. 1. Paddle 10 consists of a blade 12 having a hand side 14, a water side 16 on the opposite side of the hand side, proximal end 18, a distal end 20 opposite the distal end and opposite first and second lateral ends 22 and 24, respectively. Wrist portion 26 is formed on proximal end 18 of the blade, the wrist portion being formed and dimensioned to receive the wrist (not shown) of the user's right hand. Slits 28 and 30 are formed on wrist portion 26 to accommodate a wrist strap (not shown). The blade includes a finger portion 32 formed towards distal end 20. Apertures 34, 36, 38 and 40 are formed on finger portion 32 adjacent distal end 20. Apertures 34 to 40 are dimensioned and configured to receive the fingers of the user's right hand (not shown). The blade further includes a palm portion 46 in the approximate center of the blade between wrist portion 26 and finger portion 32 and flange portions 42 and 44. Notch 48 is provided on first latter end 22 to accommodate a user's thumb.

First and second flange portions 42 and 44, respectively, are formed on the first and second lateral ends of the blade, respectively, on either side of wrist portion 26. As best seen in FIG. 2, first flange portion 42 and second flange portion 44 are swept back from waterside 16 towards hand side 14 such that the flange portions extend upward relative to wrist portion 26 between the flanges.

Referring back to FIG. 1, finger portion 32 includes inter-digital portions 54, 55, 57 and 59. Fingertip portion 56 is formed on the blade between distal end 20 and apertures 34, 36, 38 and 40. As best seen in FIG. 3, the inter-digital portions are swept back from waterside 16 towards hand side 14 and fingertip portion 56 is swept forward from the hand side towards the waterside of the blade. Palm portion 46 of the blade is shaped such that the palm portion forms a concave surface 50 on the waterside of the blade and a slightly convex surface 52 on the hand side of the blade. Kink 113 is formed on palm portion 46 and helps form the convex surface 52 and concave surface 50. Kink 113 adds structural strength to the blade and adds to the hand comfort when the blade is worn. Furthermore, kink 113 allows for water disbursement in different directions, which reduces pressure build up, thus reducing flutter and hand strain.

Referring now to FIG. 4, when a user wears swim paddle 10, the user places hand 60 on hand side 14 of the paddle and inserts fingers 68, 70, 72 and 74 through apertures 34, 36, 38 and 40, respectively, and thumb 66 through notch 48. Wrist strap 62 must then be secured to hold the user's wrist 64 to the blade. The user's palm 76 rests on palm portion 46 of the blade and flanges 42 and 44 extend beyond the sides of the hand. As seen in FIGS. 6 and 7, the user may hold onto the paddle in one of two ways, either by curling finger tips 78 through the finger apertures to grip the blade as shown in FIG. 6 or by extending finger tips 78 such that the finger tips project outstretched as shown in FIG. 7. As better shown in 5, the swept back arrangement of inter-digital portion 55 and the swept forward orientation of finger tip portion 56 permit finger tip 78 to be fully outstretched. Since the user can fully outstretch his or her fingers while wearing the blade, the user can maintain the hand in a more comfortable and natural position, thereby decreasing muscle strain on the hand.

Referring back to FIGS. 2 and 4, flange portions 42 and 44 extend to either side of the user's hand. Since the flange portions are swept back from the waterside of the blade towards the hand side of the blade, the flange portion extends backward relative to the rest of the blade. As a result, as the blade is forced through the water by the user, the pattern of water turbulence (not shown) created by the swept back flanges greatly reduces the amount of flutter experienced by the blade. Elongated kinks (or folds) 110 and 111 help to form the flange portions and add structural strength to the blade. In addition, kinks 110 and 111 allow for a smoother water disbursement around the paddle, further reducing flutter. The reduced flutter permits the user to more easily maintain the blade in the correct orientation as the blade is forced through the water. This results in less hand strain.

The method of manufacturing the swim paddle made in accordance with the present invention will now be discussed. In one preferred fabrication method, paddle 10 is fabricated by extruding a high modulus thermoplastic into a foamed sheet of two to six thousands of an inch thick with a density of 6 to 15 pounds per cubic foot. The extruded sheet is then thermoformed into a slightly concave geometric shape, cooled and stress-stabilized using processes well known by those experienced in the art. The stress-stabilized sheet is pulled by rubber-coated rollers and cut to convenient lengths, which then pass through a vertical cutter to cut out the paddles 10 as desired in FIG. 1. Scrap sheet material is recycled.

In another embodiment of the invention, foam is injected into a reactive molding machine to form the paddle blade 12 in one operation. Any suitable elastomeric polymer resin system can be molded to the desired foam density. Feedstocks of elastomeric polymer are injected as liquids and allowed to foam, producing a smooth outer edge for the product paddle.

In the preferred embodiment of the invention, the hand paddles 10 are fabricated from a commercial grade of a homopolymer polypropylene or as a copolymer of propylene and 1-20 wt. % ethylene. These polypropylenes are in the polyolefin family of plastics. They have excellent color ability, high strength, high stiffness, excellent fatigue, chemical resistance, reasonable thermal properties, good mold ability and moderate cost. The preferred design is molded using conventional injection molding with insert pins to form the four finger holes and two slots 28 and 30, a technique well known to those skilled in the art. The finished paddles 10 are molded to a thickness of only 2 to 20 mm in order to be lightweight and use less plastic. The edges or the paddle are rounded during the molding process to prevent cuts and scratches to the swimmers hands and body. Density of the homopolymer polyethylene is 0.90 and that of the copolymers just slightly higher, such that the solid hand paddles will float in water. Copolymer paddles are slightly more flexible and much resistant to impact cracks than the homopolymer paddles but are slightly less rigid. Thus, they will not break if accidentally stepped on.

In one molding process, copolymer materials are utilized to fabricate paddles by foaming to a density of 30 to 50 pounds per cubic foot, whereas the homopolymer solid material has a density of 56.2 pounds per cubic foot. Thus, the weight of copolymer paddles can be up to one-half less than homopolymer paddles. Adequate stiffness can be achieved by modifying the injection molding process.

A copolymer of propylene and 20-40% by weight ethylene produces a more flexible hand paddle with much greater toughness, durability and resistance to impact breakage than a homopolymer process.

Copolymers can be reinforced with a small amount of glass fibers, usually 5 to 20 percent, for desired stiffness. Thus, the size and geometry of the paddles are achieved using the same molds and injection molding techniques as introduced above.

Copolymers of ethylene and a short-chain unsaturated aliphatic hydrocarbon, such as butene-1, hexene-1, octene-1 and others that are practiced for commercial copolymers called the family of high-density polyethylene (HDPE), are utilized in the molding process. Linear low-density polyethylene mixed with a compatible copolymer of HDPE can provide increased flexibility and a relatively tough surface.

Polyurethane polymers may also be used in the molding process. The advantage of the polyurethanes is that they can provide either thermoplastic or thermosetting products and can be used in reactive molding to achieve desired properties. They can also be made elastomeric and are tough enough to be used for auto tires moving at high speed, or they can be formulated for elastomer properties but low strength, for use in bed pillows. They can be also be made into rigid foams for thermal insulation. Their main disadvantage is cost.

Alternatively, paddle 10 may be formed from a thin sheet of steel, which is stamped and cut into the desired size and geometry of the paddle. The semi-finished paddle is then coated by dipping in a vinyl plastisol or another appropriate plastisol to give a surface coating to the paddle similar to that for plastic-coated wire grocery shopping carts. Many other wire products utilize plastisols, e.g. wire dish drainers and coat hangers. Plastisols offer wide flexibility in the selection of vinyl materials for ease of fabrication, final properties and/or costs, due to the unique properties of polyvinyl chloride (PVC) for being compatible with a variety of plasticizers and other organic materials.

For plastic-coated metal paddies the following formulation can be utilized: dispersed PVC powder in the high-boiling liquid di-2-ethylhexylphthalate at a ratio of 3:5 or higher, liquid to polymer, to formulate a stable, free-flowing suspension of PVC (a plastisol) for coating the hand paddle. Other plastisol formulations can be prepared using other esters of pythalic acids, esters of adipic acid, along with epoxidized drying oils, chlorinated waxes and esters of phosphoric acid.

A thin, sheet of aluminum can be utilized instead of steel. Also, this paddle product can be made stiffer by stamping portions of the metal sheet, cutting the portions and bending these portions to some angle of approximately 450 to 900 with the paddle surface, forming paddle stabilizers. When, dipped in a plastisol the resulting paddle product is reinforced for increased stiffness. The areas of the paddle, which contact the user's hand, may be filled with plastisol to give a smooth surface on the hand.

Plastic powders may be used to coat the metal-based hand paddles 10 instead of plastisols. A plastic coating material can be a homogeneous blend of a thermoplastic with colorants, fillers, stabilizers and other additives in the form of a dry, fine particle size compound similar to flour. It can be applied to the semi-finished hand paddles by first heating the paddle and then dipping it in the powder in a fluidized bed just long enough to create the desired coating thickness. Alternative coating techniques usually involve electrostatic spraying or an electrostatic bed process. The advantage of powder coating is that it is basically a chemical coating and can be applied for very thin coatings as in painting. For many applications of the hand paddles of this invention, it can provide increased performance properties to the paddle product.

A specific embodiment of the present invention has been disclosed; however, several variations of the disclosed embodiment could be envisioned as within the scope of this invention. It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.

Claims

1. A hand paddle comprising:

a. A paddle blade having a hand side and an opposite water side, a proximal end, a distal end opposite the proximal end and having a distal edge and opposite first and second lateral ends,

b. A plurality of apertures formed along the distal end of the blade and separated from the distal edge by a fingertip portion, the apertures being separated from each other by inter-digital portions, the apertures adapted and configured to receive user's fingers,

c. A wrist portion formed on the proximal end of the blade, the wrist portion having a wrist strap,

d. A palm portion formed on the blade between the apertures and the wrist portion, the palm portion forming a slightly concaved surface on the waterside of the blade,

e. A notch formed on the first lateral end of the blade, the notch being adapted and configured to receive a user's thumb,

f. A first and second flange portion formed on the first and second lateral ends, respectively, the flange portions being swept back from the water side of the blade towards the hand side of the blade, the first flange portion extending from the notch to the wrist portion, the second flange portion extending along the second lateral end from the wrist portion to the apertures,

g. The inter-digital portions being swept back from the water side of the blade towards the hand side of the blade, the finger tip portion being swept forward towards the water side of the blade relative to the inter-digital portions sufficiently to permit the users fingers to extend fully through the apertures when the paddle is worn.

2. A hand paddle comprising:

a. A blade having a hand side and an opposite water side, a proximal end, a distal end opposite the proximal end and opposite first and second lateral ends,

b. A wrist portion formed on the proximal end of the blade, the wrist portion adapted and configured to retain a user's wrist when the paddle is worn,

c. A finger portion formed towards the distal end of the blade, the finger portion being adapted and configured to retain the user's fingers when the paddle is worn,

d. A first and second flange portion formed on the first and second lateral ends, respectively, the flange portions being swept back from the water side of the blade towards the hand side of the blade, the flange portions extending from the wrist portion to the finger portion of the blade.

3. The hand paddle of claim 2 wherein the finger portion comprises a plurality of apertures formed along the distal end of the paddle, the apertures dimensioned and configured to receive the user's fingers when the paddle is worn.

4. The hand paddle of claim 2 wherein the finger portion further includes a notch on the first lateral end of the blade, the notch being dimensioned and configured to receive a users thumb.

5. The hand paddle of claim 3 wherein the distal end includes a distal edge and wherein the apertures are formed adjacent the distal edge, the apertures being separated from the distal edge by a finger tip portion adjacent the distal edge, the finger tip portion being swept back from the water side of the blade towards the hand side of the blade sufficiently to permit the fingers to be fully extended.

6. The hand paddle of claim 3 wherein the finger portion further includes a plurality of inter-digital portions between the apertures, the inter-digital portions being swept back from the water side of the blade towards the hand side of the blade sufficiently to permit the fingers to be fully extended.

7. The hand paddle of claim 6 wherein the distal end includes a distal edge and wherein the apertures are formed adjacent the distal edge, the apertures being separated from the distal edge by a finger tip portion adjacent the distal edge, the finger tip portion being positioned relative to the rest of the blade to permit the fingers to be fully extended.

8. The hand paddle of claim 2 wherein the blade further includes a palm portion positioned between the wrist portion and the finger portion, the palm portion being slightly concave on the waterside of the blade.

9. The hand paddle of claim 1 wherein the paddle is made of injection molded plastic and has a density of less than water.

10. The hand paddle of claim 9 wherein the paddle is made of injection molded foamed plastic.

11. The hand paddle of claim 1 wherein the paddle is made of stamped sheet metal.

12. The hand paddle of claim 11 wherein the paddle is coated with a plastic material.

13. A method of manufacturing the hand paddle of claim 1 comprising the steps of first extruding a high modulus thermoplastic into a foamed sheet of two to six thousands of an inch thick with a density of 6 to 15 pounds per cubic foot, then thermoforming the sheet into a slightly concave geometric shape, then cooling and stress-stabilizing the stress-stabilized sheet and then cutting out the paddles in a cutter.

14. A method of manufacturing the hand paddle of claim 1 comprising the steps of forming a metal blade having the shape of the hand paddle by stamping a sheet of metal and then coating the metal blade with a plastic material.

15. The hand paddle of claim 8 wherein the blade has a plurality of kinks.

16. The hand paddle of claim 1 wherein the blade has a plurality of elongated kinks.

17. The hand paddle of claim 16 wherein at least one of the kinks extends along the palm portion of the blade.

18. The hand paddle of claim 16 wherein at least two of the kinks separate the first and second flange portions from the palm portion.

19. The hand paddle of claim 18 wherein a kink is formed on the palm portion of the paddle, the kink forming the concave surface.