Patent Application
20230331362
This invention pertains to canoe paddles that differ in the angular relationship between the paddle blade and its handle. In particular it pertains to paddle designs in which the blade can be set straight or at an angle. Traditional paddles are straight structures with the axis of the handle extending through the length and central axis of the blade. In recent years, another design has come into use in which there is an angle between the axis of the handle and the axis of the blade.
In paddling a canoe the rower sweeps a paddle along the vessel toward the stern. The blade enters the water at an angle to the surface of the water toward the bow, becomes perpendicular with respect to that surface as it is brought back toward and past the rower, and then again assumes an angular relationship to the water surface as it reaches its stern most extension and is brought to the surface to repeat the stroke.
When moving in its most vertical and perpendicular orientation to the water surface, the blade exerts the most thrust against the water. Conversely, at the beginning of the stroke and at the end the blade is delivering least advantageous thrust as it pushes more vertically than horizontally. Serious and competitive rowers have long wished for ways to maximize blade thrust to achieve the most efficiency for the effort expended. Angled paddles have come into use to address this desire. With the blade angled slightly with respect to the handle axis, the paddle can be stroked in the water such that as it moves toward the stern it retains a more perpendicular relationship to the water surface. More thrust is attained for a greater portion of the stroke. Additionally, as it is brought to the surface at the stem, because it is slightly bent down, it exerts less thrust against the water as it is brought up and tends to lift less water. Both of these characteristics contribute to more efficient rowing with less expended effort.
However, such angled paddles are best employed on “flat” water as in lakes, and are not favorably employed in rapids or turbulent streams in which there are obstacles to be dodged with the help of the paddle. When using the paddle as a pushing tool against, for example, a rock or stream bank, a straight structure serves best. There are occasions in which canoeing may benefit from both sorts of paddling, as in paddling from a stream to enter and cross a lake. For such occasions, presently rowers who do not wish to carry two paddles must choose the straight style which can serve in both circumstances, thereby foregoing the efficiency of the bent style on the lake. In general, having available both styles entails double the cost associated with having optimal paddle equipment for all canoeing circumstances.
It would be convenient if one paddle could serve in both flat water and turbulent water by being either straight or bent as circumstances require.
The present invention addresses this need with an adjustable cogged swivel joint between the blade and handle. The rower loosens a locking nut on a through bolt, orients the blade in either the straight or angled position, and retightens the locking nut. Loosening the nut enables disengagement of the joint cogs which are then re-engaged when the joint nut is tightened in the new orientation. The through bolt and nut assembly constrains the joint cogs in their engaged condition, and the cogs provide a secure angular or straight relationship between handle and blade. This operation takes but a few seconds, and a paddle that was straight for navigating down a turbulent stream to a lake can almost instantly be converted to its most efficient angled configuration for crossing the lake.
While this discussion has considered the cogged swivel joint described in this disclosure for achieving canoe paddle angle, other designs are envisioned. For example, the preferred embodiment of the present invention provides for a single blade angle, but the concept can be extended to designs with multiple angle choices. Also, there are ample examples of friction joint designs in commerce that can in principle be employed rather than the cogs of the present invention. Additionally, lever actuation of the mechanism has been demonstrated employing a wedge for the locking function, rather than the bolt and nut of the preferred embodiment. And the invention can be applied for kayak and other vessel use, as well.
