US Patent References:
Swimming shoesBrown et al. - October 1963 - 3107372
Description:
BACKGROUND OF THE INVENTION
Most commercially accepted swimming fins or flippers are designed for freestyle or crawl swimming. These fins or flippers are generally semi-rigid elements that are secured to the wearer's foot with the major plane of the swim fin or flipper extending forwardly and in alignment with the soles of the feet. These fins or flippers are intended to assist with those swimming strokes in which the swimmer keeps his knees stiff. Such fins or flippers do not lend themselves to strokes such as the breaststroke, sidestroke, or treading water, in which the swimmer's knees are bent. Since these strokes are frequently used in lifesaving, the currently available fins or flippers are not ordinarily used for such purposes.
Some attempts have been made to design swim fins or flippers that can be used for the breaststroke and other related strokes in which the swimmer bends his knees. Exemplary of these fins or flippers are U.S. Pat. Nos. 1,836,835, 671,378, 826,145, 3,042,943, 648,697, and French Pat. No. 739070, as well as others. For a variety of reasons, each of these previously designed fins or flippers have features which substantially limit the utility of the flipper and render them of limited value commercially. For example, some of these fins or flippers have complex constructions that include wing members connected to a shoe by rods or straps. Others use skirts that are connected by fabric or light flexible webs that may collapse or permit the skirt to turn inside out. The complexities of some of these units and the requirements that the units be made of combinations of various materials or have operable mechanical elements result in swim fins or flippers which are subject to breakage, which do not operate properly at all times, are costly, and appear to be inefficient, cumbersome, and difficult to wear or use.
SUMMARY OF INVENTION
It is an object of the present invention to provide an improved swimming flipper designed primarily for use by swimmers using a breaststroke or similar stroke, such as a sidestroke, in which the swimmer bends his knees.
A further object of the present invention is to provide an improved swimming flipper that is particularly useful for treading water, and consequently, for lifesaving purposes.
One further object of the present invention is to provide an improved swimming flipper which is comfortable to wear, easy to put on, comparatively inexpensive to manufacture, and not normally in need of repair or adjustment.
A further object of the present invention is to provide a close fitting swimming flipper which may be worn by the wearer while walking with comparative comfort, and which is not likely to inadvertently come off while swimming or walking.
The present invention provides a swimming flipper designed primarily to be worn on the foot for assisting the wearer to swim with a stroke which requires knee bending. In the present invention there is provided a shoe and a skirt integrally molded of a rubber or flexible plastic material. The shoe is provided with an upper having a periphery defining an opening adapted to fit about the ankle of the wearer, and with a lower periphery defining the lower edge of the upper and a sole continuous with the upper. The skirt is formed of a substantially uniformly thick, continuous wall having an upper edge and a lower edge, with the upper edge continuous with the periphery which defines the foot opening of the shoe, and with the lower edge of the skirt at least as twice as long as the upper edge of the skirt. The skirt is integrally connected to the shoe only along a web extending from the bottom to the top of the heel of the shoe, and along a web and bead from the toe upwardly and substantially symetrically to the forward portion of the opening, as well as along a common line of the upper periphery and the upper edge. The skirt is also provided with a plurality of integrally formed ribs extending downwardly to the lower edge of the skirt.
DESCRIPTION OF DRAWINGS
The foregoing objects and advantages of the present invention will be more clearly understood when considered in conjunction with the accompanying drawings, in which:
FIG. 1 is a top plan view of the invention;
FIG. 2 is a side elevational view;
FIG. 3 is a bottom plan view;
FIG. 4 is a cross sectional view taken essentially along the line 4--4 of FIG. 1, and;
FIG. 5 is a cross sectional view taken essentially along the line 5--5 of FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to the drawings, there is illustrated a preferred embodiment of the present invention. The unit is made of an integrally molded shoe 10 and skirt 11. The material from which this fin or flipper is made may be any of a well known variety of elastomeric materials such as natural or synthetic rubber, polypropylene, polyethylene, polyvinyl chloride, or other polymeric or copolymeric elastomeric materials capable of being molded. The material must have sufficient flexibility so as to permit the skirt to be flexed to, and away from, the shoe upon the appropriate application of water pressure; but the material must have sufficient rigidity so that the ribbed skirt will maintain its generally truncated conic shape during flexing or movement.
The shoe 10 is shaped with an upper 12 and sole 13. Preferably, the sole 13 is symetrical along a longitudinal axis so that it may be worn on either foot. It should also be recessed slightly from the lower periphery 15 of the shoe upper. The upper periphery of the shoe opening 16 defines an opening adapted to fit about the ankle of the wearer. A continuous flap 17, having a thickness substantially thinner than the wall of the shoe, extends upwardly from the upper periphery 16 of the shoe and is designed to provide a snug fit about the ankle region of the wearer. The inner surface of flap 17 is continuous with the inner surface of shoe 10. If desired, the bottom of the shoe sole 13 may be provided with reinforcing ribs 18 and 19, some of which may, if desired, be shaped in the form of a trademark or other advertising material such as illustrated in FIG. 3. The surface of the ribs 18 and 19 are preferably planar with the surface of lower periphery 15. The walls of the upper and the sole are of uniform thickness and have a thickness which is the same as the thickness of skirt 11.
Skirt 11 is formed of a continuous wall with an upper continuous edge 20 that is coincident with the upper periphery 16 of the shoe 10. The lower continuous edge 21 of the skirt is essentially coplanar with the lower periphery 15 of the shoe, and has a length preferably at least twice the length of the upper continuous edge 20.
The skirt 11 in a normal non-deformed configuration is arranged with its lower continuous edge 21 spaced outwardly from the lower periphery 15 of the shoe at a distance in the order of magnitude that is about one half the sole at that particular point. This spacing varies somewhat with the maximum spacing between the lower edge of the skirt and the lower periphery of the shoe occurring along the sides of the shoe just forward of the instep region of the shoe between points 24 and 25. The forward portion of the skirt 11 tapers toward the toe where it is secured to the toe by a web 26. The web 26, in turn, tapers from a wide point at its lower end 28 (FIG. 2) to a point 29 just above the toe of the shoe. From point 29 to the forward portion 30 of the opening, the skirt 11 and shoe 10 are joined along a narrow continuous bead. A reinforcing rib 31 extends from the forwardmost portion of the skirt 32 towards the forwardmost portion of the opening and is directly over the bead along which the shoe and skirt are integral.
The rear of the skirt forms segments 36 that are bowed rearwardly of the heel 34 and are symetrical with respect to it. A convoluted segment 37 continuous with the segments 36 is integrally joined to the rearmost portion of the heel 34 by a web 38. The web 38 is essentially triangular in planar arrangement and extends from a wide base at the lower portion of the heel to a tapered top towards the upper end of the heel.
The skirt is thus integrally connected to the shoe only along a line coincident with the longitudinal axis of the shoe and at the periphery of the shoe opening.
The skirt is also formed with a plurality of ribs 40. These ribs are preferably arranged in a symetrical fashion on either side of the longitudinal axis of the fin with the three ribs parallel to one another on each side. Each rib is preferably formed with mutually angular segments 41 and 42. In cross section, each rib has essentially an inverted V-shape configuration. Preferably, one set of ribs is located intermediate the shoe opening; a second set is located at the forward end of the opening; and a third set above the vamp of the shoe. The ribs provide spaces on the inner surface of the skirt through which water may readily flow, thus providing means by which there is little likelihood of the skirt sticking to the shoe. The ribs also prevent the skirt from inadvertently turning inside out.
In the use of this footwear, the wearer can use the fin without altering his swimming style. When the swimmer kicks with a bended knee, water is caught in the skirt between the inner surface of the skirt and the shoe. This flexes the skirt away from the shoe, but nonetheless, the skirt acts as an umbrella-like retainer. When the swimmer draws his foot towards him, the water pressure collapses the skirt against the shoe, thus compressing the fin and permitting the drawing movement of the kick without substantial interference from the flipper. The cycle is again repeated when the swimmer thrusts his foot rearwardly, thereby spreading the skirt and effectively providing a wider base against which the swimmer may exert force.