Flapping paddle and vertical stabilizer for swimmer

A swimming paddle assembly has a long shaft with a rigid blade at each end. A pair of resilient flaps are attached to the leading edge of each blade, one on each side, so that as the swimmer pulls first on one side of the shaft and then the other side, one blade is pushed forward and the other is pulled back on a power stroke with the flaps open for greater resistance. On the return stroke the flaps are forced closed against the blade sides for reduced resistance. One or more vertical stabilizing panels attached to the lower limbs reduce side to side motion of the lower body. These may be on swim fins or mounted between the legs.

BACKGROUND OF THE INVENTION 
This invention relates to hand operated swimming aids and more particularly 
to paddles with movable flaps and vertical stabilizers for use with the 
paddles. 
U.S. Pat. No. 5,348,503 issued Sep. 20, 1994 to the applicant discloses a 
paddle with a blade at opposite ends of a hand held shaft. Each blade has 
a rigid leading edge and a flexible following portion. When pushed 
forward, the blade lies in a plane for minimal resistance. When pulled 
backward on the power stroke, the following portion bends out of the 
plane, creating increased resistance for enhanced propulsion. This pulling 
action causes torso and legs to move from side to side, reducing the 
forward power thrust. A vertical blade held on both feet acts as a keel or 
stabilizer to reduce the lateral motion and convert it to forward thrust. 
Canadian Patent No. 757954 issued May 1967 discloses a double ended 
swimmer's paddle with hinged flaps. The flaps are supposed to open on the 
power stroke, with cords 19 limiting the extent of opening, to create high 
resistance, and to close on the return stroke for low resistance. If the 
angle of attack is not directed between the flaps, the flaps will move in 
the same direction, reducing their utility. On the power stroke the flaps 
tend to vibrate, increasing resistance without adding thrust. 
U.S. Pat. No. 2,948,255 issued Aug. 9, 1960 to Sbrana discloses resilient 
paired flaps that reciprocate on a paddle mechanism mounted beneath a 
water craft. 
U.S. Pat. No. 5,362,268 issued Nov. 8, 1994 to Nordbeck discloses a foot 
mounted swim fin. The fin has resilient side panels which tend to bend 
toward one another on the return stroke. 
U.S. Pat. No. 3,510,894 issued May 12, 1970 to Eriksen and U.S. Pat. No. 
5,114,371 issued May 19, 1992 to Alonzo disclose a floating double ended 
paddle that buoys the swimmer and provides propulsion, the paddle ends are 
rigid. 
U.S. Pat. No. 3,987,509 issued Oct. 26, 1976 to Patterman discloses a 
swimming tail formed by a pair of flippers to be used side by side to 
simulate the vertical tail of a fish, one flipper has a fin that extends 
back from the heel of the foot and the other has a fin that extends 
forward from the toe of the foot. Thrust is generated by lateral motion of 
the pair. 
U.S. Pat. No. 4,857,024 issued Aug. 15, 1989 to Evans teaches a swim fin 
mounted on the foot with a shaped, horizontal blade having special flexing 
responses that are greater when forced through the water in a first 
direction than in a second direction so that greater resistance is offered 
on the power stroke of the kick and less on the return stroke. The 
propelling force is developed by a combination of the flexing of the 
deflectable end and the snapping action of the movable tips. 
The prior art does not consider the problems related to flaps not opening 
correctly when the angle of attack changes nor to vibration of the flaps. 
SUMMARY OF THE INVENTION 
The instant invention overcomes problems encountered by the prior art by 
mounting a non-movable blade between two resilient flaps. A non-movable 
blade is mounted at a fixed position at each end of an elongate hand held 
shaft assembly. The two blades are coplanar. A pair of resilient flaps are 
each attached to the leading edge of a blade, one on each side. They 
extend to or past the trailing edge of the blade. When the swimmer pulls 
the blade on the power stroke, the flaps can only move in one direction, 
away from the blade, to thereby open wide to greatly increase hydrodynamic 
resistance. When the swimmer pushes the blade forward on the return 
stroke, the flaps are forced to lie flat against the blade, thereby 
greatly reducing resistance that would slow the swimmer. 
The pulling action of the power strokes so far from the swimmer's torso 
causes the legs and torso to move laterally from side to side, lessening 
the effective forward vector. Vertical keels or stabilizing fins attached 
to the feet or legs may be employed to reduce the side to side motion. The 
vertical blade or fin that has foot receiving pockets on each side as 
disclosed in Applicant's U.S. Pat. No. 5,348,503 may be used for this 
purpose. It acts like a fish's tail, converting the legs lateral motion 
into forward thrust. 
Swimmers may prefer to use more conventional leg swimming motions such as 
those that are used in conjunction with swim fins. These employ the major 
muscles that will enhance propulsion and exercise muscles used in training 
for athletic competition and in physical therapy. It is accordingly an 
object of the invention to provide vertical stabilizing fins or blades 
that attach to the feet or legs that are usable with the paddle and that 
enable the feet to kick alternately with swim fins. 
These and other objects, advantages and features of the invention will 
become more apparent when the detailed description is studied with the 
drawings, in which like reference characters designate like elements in 
the various figures.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring now first to FIGS. 1-5 and 9, a paddle assembly 1 has an elongate 
shaft 2 with a long axis 3, an intermediate portion 4 connecting two end 
portions 5. The intermediate portion is provided with hand grips 22. 
As best seen in FIG. 9, a swimmer grasps the hand grips 22 and applies 
alternating fore and aft motions with the arms. As shown, the left arm 23 
is executing a pulling stroke in the direction of arrow 14 and the right 
arm (not shown) is executing a return stroke in the direction of arrow 13, 
while the swimmer's swim fins 24 are executing alternating kicking 
strokes. 
A rigid blade 6 having a free trailing edge 7 and a leading edge 8 is 
affixed to each end portion 5 at the leading edge 8 so as to maintain both 
blades in a common plane. 
Each blade is provided with a pair of resilient flaps 9, one on each side 
of the blade, and attached to the leading edge 8 of the blade on an 
anterior margin 11 such that the posterior margin 12 of each flap is free 
to move away from the blade on a pulling stroke 14 as seen in FIGS. 5 and 
9 for increased hydrodynamic resistance and to move against the side 25 of 
the blade on a return stroke 13 as seen in FIGS. 4 and 9 for reduced 
resistance. 
The paddle assembly may be made with positive, neutral or negative buoyancy 
to satisfy particular requirements. The blade 6 of FIG. 4 shows a negative 
buoyancy configuration with a small cross section. The blade 6 of FIG. 3 
shows a positive buoyancy configuration with a large cross section 
comprising a rigid plastic shell 16 filled with low density closed cell 
foam plastic 15. 
The flaps may be made of a resilient material such as rubber or an 
elastomer having elastic properties and designed to open wide on the 
pulling stroke and may store enough elastic energy on opening that they 
impart a forward thrust when they release that energy by snapping closed 
when the pulling stroke stops. 
FIGS. 6-8 illustrate an embodiment in which the rigid blade 6 is 
constructed for removably attaching a removable flap assembly 17 so that 
the paddle may be used with various flap assemblies having different 
properties such as greater resilience, area and the like, as desired. A 
notch 19 in the leading edge 8 of the blade 6 receives a projection 18 
molded into the flap assembly 17 and a bolt (not shown) passes through 
bolt holes 20 and 21 to hold the flap assembly securely in place. 
Referring now to FIGS. 9-11, it is understood that the alternating pulling 
strokes of the paddle assembly has two principal effects. It causes 
forward propulsion by pulling on the swimmer's shoulders. It also rotates 
the torso about the shoulders, moving the lower body from side to side and 
dissipating some of the energy that could otherwise generate propulsion. 
Vertical stabilizing means 26 that present at least one broad panel 27 in a 
plane transverse to the side to side motion are removably attached to the 
lower limbs of the swimmer to reduce the side to side motion so that more 
energy is directed to forward propulsion. 
A broad panel web 27 is constructed to be removably attached about the 
lower limbs 28 by detachable straps 31 which attach to the web 27 by hook 
and loop fasteners 36 at the two opposed edges 30. 
This panel web 27 may be made of an elastic fabric so that the feet may be 
provided with swim fins 29 for alternating kicking strokes. During the 
kicking strokes the panel moves to alternating partially vertical 
positions to restrain the side to side motion. 
FIGS. 12 and 13 show a modified swim fin 29 provided with conventional 
broad horizontal blade 32 and a foot attaching means 34. 
The fin is provided with a vertical panel 33 affixed to the fin generally 
orthogonal to the horizontal blade 32 to present a vertical stabilizing 
means in an orientation transverse to the side to side motion of the 
torso. The stabilizing means may also enhance propulsion much like a fish 
tail as it is forced from side to side. To further maintain the position 
of the vertical panel 33, it may be provided with a strap 35 for securing 
about the lower limb. 
The above disclosed invention has a number of particular features which 
should preferably be employed in combination although each is useful 
separately without departure from the scope of the invention. While I have 
shown and described the preferred embodiments of my invention, it will be 
understood that the invention may be embodied otherwise than as herein 
specifically illustrated or described, and that certain changes in the 
form and arrangement of parts and the specific manner of practicing the 
invention may be made within the underlying idea or principles of the 
invention within the scope of the appended claims.