Previously, many types of systems have been developed in the field of watercraft propulsion, such as oars in rowboats or rowing shells wherein the rower pulls a pair of oars against a pivot point creating the motivational force. Attempts have been made to improve this method of propulsion, including foot actuated paddles, sliding rowing seats, and specifically placed oar locks. Exercise machines have also attempted to duplicate this motion in a stationary manner. A search of the prior art did not disclose any patents that read directly on the claims of the instant invention, however, the following U.S. Patents were considered related:
______________________________________ U.S. Pat. No. Inventor Issue Date ______________________________________ 4,353,703 d'Elloy Oct. 12, 1982 3,802,008 Gongwer Apr. 9, 1974 3,204,699 Gongwer Sep. 7, 1965 3,204,262 Gongwer Sep. 7, 1965 3,122,759 Gongwer Mar. 3, 1964 2,557,972 Jewett June 26, 1951 2,033,637 Kaiser Mar. 10, 1936 818,986 Tubbs Apr. 24, 1906 188,131 Harrington Mar. 6, 1877 183,265 Isaacs, Jr. Oct. 17, 1876 89,663 Heroux May 4, 1869 ______________________________________
d'Elloy teaches a pedal operated nautical propulsion device utilizing a crank system producing circular motion, which is transmitted by a frame supported mechanism to a holder carrying a paddle, allowing the paddle to be driven into the water. This circular motion is translated into a vertical plane propelling the craft, which is, in turn, raised for another stroke.
Jewett utilizes an apparatus similar to the sliding seats used in rowing shells. Along with this movable seat, the oars are longer with supplemental outrigger oar lock sockets positioned outboard of the craft. This allows conventional oars and oar locks to be employed, however, altering the position of interface with the boat. The oar lock is extended outboard instead of on the gunwale, as normally employed.
Kaiser teaches a manual propelling and steering device for boats. The rowing takes place with the oarsman facing forward on a movable seat. Foot rests are provided that are stationary, and a standard supports a pair of oars that are hinged on the end and gripped along the shaft with no provision changing the angular pitch of the blade.
The oars are convertible, allowing them to be removed and attached together to form a paddle with the standard folding down, out of the way for convenience.
Tubbs employs oars mounted in locks on each gunwale with cables, or other suitable flexible traction elements, attached from the oars to a hinged seat. In operation the oarsman moves back and forth while stroking, rocking the seat forward on pivots with power being applied to the oars through the cables assisting the arm movement. The motion becomes uniform and simultaneous owing to the connection of the rod transmitting motion from the seat to the oars.
Heroux practiced over a century ago a foot cross bar attached on each end with a chain to a lever pivoting on the front edge of a seat. These levers connect to the oars on the opposite end. In operation the oarsmans feet are drawn back and pushed forward at each stroke of the oars, assisting the propulsion of the watercraft with the oars used in a conventional manner.
For background purposes and as indicative of the art to which the invention relates reference may be made to the remaining cited patents issued to Gongwer, Harrington, and Isaacs, Jr.