Amusement devices: toys – Aquatic
Reexamination Certificate
1999-05-07
2002-05-07
Rimell, Sam (Department: 3712)
Amusement devices: toys
Aquatic
C446S046000
Reexamination Certificate
active
06383052
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The present invention relates generally to aquatic, surface skimming devices, and more particularly to a safer aquatic, surface skimming device designed for use in varying water conditions.
2. Discussion of the Related Art
The beach activity of throwing flat round stones, sand dollars, or sea shells, in a manner in which causes the flat round projectile to rotate on a center axis, which can either take flight or be skipped over the surface of the water, is an ageless and timeless activity fascinating both young and old since antiquity. The airborne activity of sailing stones and sea shells has been modernized to what is now known as Frisbee throwing, that is, the gyroscopic propelling of an aerodynamically contoured plastic flying disk.
The large market for flying disks, such as frisbees, has been established because the products offer the consumer, not only fun and exercise, but a fascinating experience with the laws of gyroscopic aerodynamics which far surpass the common experience of sailing stones or shells. Though made of semi-rigid materials, they are lightweight and feature a smooth bulbous perimeter.
Most people have experienced skipping stones on the water. People enjoy the excitement of a well-skipped stone because it seems to defy natural law. However, rocks are skipped out over open water away from people. Unlike the sea shell's successful transformation to plastic flying disk, the activity of skipping stones on the water has yet to evolve into a higher performing, practical and popular commercial alternative. One could conclude, that the success of a manufactured water skimming device, which could travel long distances on the water, would depend on the consumer experiencing a fascination with a new physical phenomena while experiencing a significant degree of security about the softness of the product.
One significant drawback of other aquatic devices is that they exhibit significant hydrodynamic drag due to a beveled or radiused lower edge. Non-gyroscopic hydrodynamic planing, such as with boats, requires a contoured leading edge and a sharp trailing edge. Previous inventors have assumed that a contour or beveled angle of some sort is desirable at the leading edge of a disk to break the water, as is proven in boat design. As seen in this previous design, radial contours between the bottom surface and side wall allow water to continue up the side wall and break loose above the normal water level, especially at moderate to slower speeds of the disk. Any bevel or radiused edge at the running surface perimeter will draw water and pull the disk down below the air water interface, thus causing drag.
Another significant drawback of these inventions is that substantial force is transferred through the leading edge of the disk when it makes contact with another person or object. Though not mentioned in these other inventions, soft or low density foam can't be used alone to cushion the sides of the disk effectively because it is hydrodynamically unstable. Furthermore, soft foam alone squishes too easily when gripped and is too flexible for controlled throwing or passing of the disk. Using lightweight foam can limit the total weight of the disk, thus reducing momentum and subsequent distance. Also, lightweight foam has less mass and material, and therefore is not as durable. If the product wears or tears, the geometry changes and effects performance.
Still, another important drawback of the previous designs is that a pressure grip is required in throwing the disk. Because the disk is wet, often times a secure grip is difficult to achieve because shear tension between the hand and the disk develops when centrifugal forces occur in the throwing motion. These older inventions show a tapering from the center of the disk outwardly, encouraging the pressure grip of the hand to slide off the disk. Should such a disk be made of soft foam, it may be even harder to achieve a sufficient grip to maintain control during the throwing motion.
The patent to Richard G. Panse, U. S. Pat. No. 4,463.954, shows a water skimming device with a lower surface divided into two subsurfaces, a small central flat bottom surface transitioning or tapering to a more conical outer tapered surface surrounding that central bottom surface. In the various embodiments shown by Panse, the angle of taper or angle “alpha” between the central flat bottom and the surrounding tapered wall is always less than 30 degrees. The Panse design exhibits poor hydrodynamics because water is forced to change course from the flat area to the conical area at the trail edge because the angle of change is less than 45 degrees. Also, the Panse patent states that the bottom central flat surface is small as seen in
FIG. 2
of the Panse drawings, possibly 30% or less of the diameter of the entire disk. Panse teaches an operative radius ratio of 0.5 and under. Based on the weight and size of the Panse invention, the small inner flat surface cannot support the disk for very long at the rate of speed prescribed. Panse verifies this by stating that his disk will travel only 25 feet, at 16 miles per hour at initial projection. After 20 or so feet, the speed of the disk slows and then the small inner surface cannot support the overall weight, thus the disk sinks slightly, causing drag on the conical outer surface. Testing revealed that if the radius ratio is less than 0.80, then the alpha angle is too small to effect proper water release at the trailing edge of the disk, thus producing unwanted drag. In
FIG. 7
of Panse, a symmetrical device as viewed from a side elevation, featuring a dual surface bottom, vertical side walls, rounded corners and no handle is shown. Panse states that the subsequent distances obtained by his invention averaged about 20 feet, with all distances less than 25 feet.
The disk of Thomas L. Clark shown in U. S. Pat. No. 4,979,922 shows a common flying disk and an insert which is placed into the flying disk to adapt it to skipping across the water. Clark rightly shows a rounded lower outside edge on the flying disk in his drawings. For aerodynamic reasons, flying disks are molded from a semi-rigid solid plastic, featuring an intentionally and purposefully rounded lower outside edge. The aerodynamics of the flying disk are enhanced by rounding this edge. Also, this edge is rounded because the user's hand firmly rubs across this surface each time the disk is thrown in the air. If flying disks were made with sharp lower rim edges they would cut, blister, and chafe the user's fingers when used in the air without an insert. The addition of a Clark insert into a flying disk fits up against the inside edge of the rim, therefore leaving the rounded lower outside edge unchanged. For aerodynamic lift in flight, the Clark invention also shows a classic frisbee ellipsoidal arc profile with the leading edge being substantially below the horizontal center plane of the disk, not above. Additionally, Clark does not show a significant mechanical handle grip on the top side of his flying disk. Instead, Clark's invention shows a concave handle grip on the underside insert. The nature of Clark's design is the adaptation of a common flying disk, like the frisbee which requires a grip on the underside. Clark also states that his disk and insert are made from lightweight substantially rigid materials. This combination is operatively and practically ineffective.
The balance of other disk designs mentioned above are for improvements to a flying disk only, each of which are hollow on the underside.
It is accordingly an object of the present invention to provide an aquatic device which will travel great distances across the surface of a body of water.
It is another object of the present invention to provide an aquatic device which will function in rough water conditions.
It is another object of the present invention to provide an aquatic device which is designed to minimize the impact force of the device.
It is yet another object of the present inv
Chasteen Kimberly A
Rimell Sam
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