WO2022133572A1

WO2022133572A1 - Multi-bladed paddle

Info

Publication number: WO2022133572A1
Application number: PCT/CA2020/051802
Authority: WO
Inventors: Robert Andrew GREENAWAY
Original assignee: Okanagan Sky Paddle Ltd.
Priority date: 2020-12-24
Filing date: 2020-12-24
Publication date: 2022-06-30

Abstract

A paddle is disclosed, wherein the paddle comprises a shaft extending along a shaft axis, wherein the shaft has a first end and an opposing second end; a first blade extending from the first end of the shaft and at a first blade angle to the shaft axis; and a second blade extending from the shaft at a second blade angle to the shaft axis, wherein the second blade angle is unequal to the first blade angle.

Description

MULTI-BLADED PADDLE

Technical Field

[0001] The present disclosure relates to a manual propulsion device for an aquatic conveyance. More particularly, the present disclosure relates to a multi-bladed paddle for an aquatic conveyance such as a paddleboard.

Background

[0002] An aquatic conveyance may be manually propelled by a user of said conveyance. For example, paddles and/or oars may be used to propel an aquatic conveyance such as a paddleboard, kayak, canoe, dinghy, and the like. As a further example, a paddleboard may be paddled with a paddle by a paddler.

[0003] A paddle used to propel an aquatic conveyance such as a paddleboard generally comprises a blade attached to an end of a shaft. To propel a paddleboard with such a paddle, a paddler grasps the shaft of the paddle, and strokes the paddle through the water adjacent to the paddleboard.

[0004] Paddles are generally configured to transfer a force applied by a paddler on a shaft of the paddle to a blade of the paddle, and from the blade of the paddle to the water. A paddler may adjust the magnitude and direction of the force on the water from the blade of the paddle by adjusting the magnitude and direction of their force on the shaft of the paddle. The paddler may direct a paddleboard by controlling the magnitude and the direction of the force on the water from the blade of the paddle.

[0005] The inventor has recognized a need for an improved manual propulsion device for of an aquatic conveyance, for example a paddle for a paddleboard.

[0006] The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings. Summary

[0007] The following embodiments and aspects thereof are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the problems described herein have been reduced or eliminated, while other embodiments are directed to other improvements.

[0008] One aspect of the invention provides a paddle comprising: a shaft extending along a shaft axis, wherein the shaft has a first end and an opposing second end; a first blade extending from the first end of the shaft and at a first blade angle to the shaft axis; and a second blade extending from the shaft at a second blade angle to the shaft axis, wherein the second blade angle is unequal to the first blade angle.

[0009] In some embodiments the second blade extends from the shaft between the first end and the second end.

[0010] In some embodiments the second blade angle is greater than the first blade angle.

[0011] In some embodiments the first blade extends from the shaft by a first blade length; the second blade extends from the shaft by a second blade length; and the second blade length is greater than the first blade length.

[0012] In some embodiments the first blade has a first blade width perpendicular to the first blade length; the second blade has a second blade width perpendicular to the second blade length; and the first blade width is substantially equal to the second blade width

[0013] In some embodiments the first blade extends from the shaft along a first blade axis; the second blade extends from the shaft along a second blade axis; and the first blade axis, the second blade axis and shaft axis lie within a plane.

[0014] In some embodiments the first blade angle is in the range of 0 degrees to 12 degrees, and/or the second blade angle is in the range of 7 degrees to 19 degrees.

[0015] One aspect of the invention provides a paddle comprising: a shaft extending along a shaft axis, wherein the shaft has a first end and an opposing second end; a first power surface extending from the first end of the shaft and at a first surface angle to the shaft axis; and a second power surface extending from the shaft above the first power surface and at a second surface angle to the shaft axis, wherein the second surface angle is unequal to the first surface angle.

[0016] In some embodiments the first power surface is provided by a first blade, and the second power surface is provided by a second blade.

[0017] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions.

Brief Description of the Drawings

[0018] Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.

[0019] Figures 1 A and 1 B are schematic diagrams of a paddler paddling a paddleboard with a prior art paddle.

[0020] Figure 2A is a front view of a paddle according to an example embodiment of the present invention.

[0021] Figure 2B is a side view of the paddle depicted in figure 2A.

[0022] Figure 2C is a partial side view of the paddle depicted in figure 2A.

[0023] Figures 2D and 2E are respective partial front and partial back views of the paddle depicted in figure 2A.

[0024] Figures 2F and 2G are respective end views of first and second blades of the paddle depicted in figure 2A.

[0025] Figures 2H and 2I are partial perspective views of the paddle depicted in figure 2A.

[0026] Figures 3A to 3E are partial side views of the paddle depicted in figure 2A at various positions along a paddle stroke. Description

[0027] Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.

[0028] To propel an aquatic conveyance, for example a paddleboard, with a paddle, a paddler strokes the paddle through the water adjacent to the paddleboard. By stroking the paddle through the water, the paddler exerts a force on the water with a blade of the paddle. Stroking the paddle through the water also exerts a force on the blade of the paddle from the water. The force on the blade of the paddle is transferred through the shaft of the paddle to the paddler and from the paddler to the paddleboard, thereby propelling the paddleboard.

[0029] To control a velocity (speed and direction) of the paddleboard, the paddler controls a magnitude and a direction of their force on the paddle, and thereby controls a magnitude and a direction of a force on the water from the blade of the paddle. The direction of the force on the water from the paddle blade during the paddle stroke is generally opposed to a power surface of the paddle blade. The power surface of the blade is the surface of the blade that is pulled against the water during the paddle stroke.

[0030] The magnitude of the force on the water from the blade of the paddle is dependent on a speed at which the paddler strokes the paddle, an orientation of the paddle during the paddle stroke, and a depth of the paddle blade in the water. The direction of the force on the water from the blade of the paddle is dependent on a direction in which the paddler strokes the paddle and the orientation of the paddle during the paddle stroke.

[0031] An ideal paddle stroke is one which maximizes the transfer of force applied on the paddle by the paddler into useful force on the water from the paddle blade during the paddle stroke. The useful force on the water from the paddle blade is the portion (or “component”) of the force on the water from the blade that is opposed to a desired direction of travel. For example, where the desired direction of travel is from a rear of the paddleboard towards a front of the paddleboard (for example when the paddler is paddling the paddleboard forward), the useful force on the water from the blade is the portion of the total force on the water from the blade that is in a direction from the front of the paddleboard towards the rear of the paddleboard.

[0032] The portion of force on the water from the paddle that is useful force during the paddle stroke depends on the orientation of the paddle during the paddle stroke, and the path of the paddle blade through the water during the paddle stroke. The path of the paddle blade through the water during the paddle stroke may be referred to as the stroke trajectory.

[0033] Figure 1A is a schematic diagram of paddler 20 paddling paddleboard 22 with a prior art paddle 24. Paddle 24 has blade 26. Line T1 represents ideal stroke trajectory T 1 of blade 26 for paddler 20 to paddle paddleboard 22 forward. Ideal stroke trajectory T1 is a horizontal line adjacent to paddleboard 22 and from a front of paddleboard 22 towards a rear of paddleboard 22.

[0034] Figure 1 B is a schematic diagram of paddle 24 paddled by paddler 20 at the start and end of a paddle stroke.

[0035] In practice, the trajectory of blade 26 during the paddle stroke varies from ideal trajectory T1 , in part due to the relatively fixed position the paddler 20 on paddleboard 22 during the paddle stroke, and the biomechanics of paddler 20. Line T2 represents an example non-ideal stroke trajectory T2 of blade 26.

[0036] During a typical paddle stroke, paddler 20 extends paddle 24 into the water in front of themselves, and draws paddle 24 through the water towards themselves. Paddler 20 may draw paddle 24 through the water until paddle 24 is near themselves, or until paddle 24 extends behind themselves. As such, non-ideal stroke trajectory T2 will tend towards an arc as paddler 20 extends paddle 24 into the water in front of themselves, and draws paddle 24 along the side of the paddleboard.

[0037] Blade 26 exerts force F1 on the water. Useful force F2 is the portion of force F1 opposed to the desired direction of travel, in figure 1 B being from a rear of paddleboard 22 towards a front of paddleboard 22. Accordingly, the ideal orientation of blade 26 during the paddle stroke is perpendicular to the desired direction. Orienting blade 26 perpendicular to the desired direction maximizes the amount of force F1 opposed to the desired direction, and therefore maximizes useful force F2.

[0038] Each stroke requires paddler 20 to withdraw blade 26 from the water at the end of the stroke, reposition blade 26 towards the start of the stroke, and insert blade 26 into the water at the start of the stroke. As such, the longer the stroke trajectory, the relatively fewer number of times paddler 20 will need to reposition the paddle. Therefore, a longer stroke trajectory results in relatively less wasted effort repositioning the paddle after each stroke. However, the longer the stroke trajectory, the more paddle 24, and therefore blade 26, rotates over the stroke.

[0039] When paddler 20 extends paddle 24 into the water in front of themselves, paddle 24 forms an obtuse starting angle between the front of paddle 24 and a surface of the water. As paddler 20 draws the paddle towards themselves and then behind themselves, the angle between the front of paddle 24 and the water surface will decrease. If paddler 20 withdraws paddle 24 from the water when paddle 24 is near themselves, the front of paddle 24 may be near to perpendicular with the water surface. If paddler 20 extends the paddle stroke behind themselves, the front of paddle 24 may form an acute angle with the water surface.

[0040] As paddle 24 rotates during the paddle stroke from the obtuse starting angle to the perpendicular or acute ending angle, blade 26 will rotate with paddle 24, thereby varying in orientation. As blade 26 rotates over the paddle stroke, the proportion of force F1 that is useful force F2 will vary.

[0041] A paddle may be designed to extend the length of a stroke. For example, blade 26 may be mounted at a forward angle to shaft 24, as depicted in figures 1 A and 1 B. Blade 26 is mounted at a forward angle to shaft 24 when blade 26 is angled towards the front of the stroke. Mounting blade 26 at a forward angle to shaft 24 extends blade 26 away from paddler 20 and towards the front of the stroke when blade 26 is inserted into the water. Extending blade 26 towards the front of the stroke allows paddler 20 to draw paddle 24 further along the stroke trajectory before blade 26 is perpendicular to the water surface, thereby extending the length of a useful stroke of paddle 24.

[0042] A paddle may be designed to maximize the amount of force from the paddle on the water that is useful force on the water at a certain point along the stroke trajectory. For example, a blade may be mounted at an angle to a shaft so that when the paddle is it or near the acute ending angle, the blade is oriented nearer to perpendicular with the stroke trajectory than at the starting angle. So mounting the blade may increase the proportion of force on the water from the blade that is useful force towards an end of the stroke. However, no matter the angle at which the blade is mounted to the shaft, the blade will only be near to perpendicular to the stroke trajectory at one angle of the shaft to the water surface.

[0043] In the present invention, two or more blades are mounted at different angles to a paddle shaft. Because the blades are at different angles to the shaft, each of the blades may be perpendicular to the water surface at a different orientation of the paddle to the water surface. Accordingly, as the paddle changes orientation over a non-ideal paddle stroke, each of the blades is nearer to perpendicular at a different point along the paddle stroke. Because each of the blades is nearer to perpendicular at a different point along the paddle stroke, more force on the water from the paddle is useful force over the paddle stroke.

[0044] Figure 2A is a front view of paddle 100 according to an example embodiment of the present invention. Paddle 100 comprises shaft 10, first blade 12, second blade 14 and handle 16. First blade 12 has first power surface 13, and second blade 14 has second power surface 15. First blade 12 and second blade 14 (referred to as blades 12 and 14), and therefore first power surface 13 and second power surface 15 (referred to as power surfaces 13 and 15) extend from shaft 10 at different angles to shaft 10. Because power surfaces 13 and 15 extend from shaft 10 at different angles, each of power surfaces 13 and 15 is perpendicular to the surface of the water at a different point along a stroke of paddle 100. Accordingly, the amount of force on the water from paddle 100 that is useful force will be maximized near the two points along a stroke of paddle 100 where one of power surfaces 13 and 15 are near to perpendicular to the water surface.

[0045] Blades 12 and 14 may be integrally formed with shaft 10. Blades 12 and 14 may be attached to shaft 10, for example by fasteners such as screws, rivets, or bolts. Blades 12 and 14 may be joined to shaft 10, for example by fusing or soldering blades 12 and 14 to shaft 10.

[0046] Paddle 100 may be used by a paddler to paddle a paddleboard. A paddler may paddle a paddleboard with paddle 100 by grasping shaft 10 and handle 16, and stroking paddle 100 through the water adjacent to the paddleboard.

[0047] Figure 2B is a side view of paddle 100. First blade 12 extends from shaft 10 at or near first end 10A of shaft 10. Handle 16 is mounted to shaft 10 at or near second end 10B of shaft 10. First end 10A opposes second end 10B. In some embodiments, second blade 14 overlaps first blade 12 by an overlap length.

[0048] Second blade 14 may extend from shaft 10 at or near where first blade 12 extends from shaft 10. Second blade 14 may extend from shaft 10 between first end 10A and second end 10B.

[0049] In some embodiments, first blade 12 extends from shaft 10 at a point along shaft 10 that is a length L1 along shaft 10 from where handle 16 is mounted to shaft 10.

Second blade 14 extends from shaft 10 at a point along shaft 10 that is a length L2 along shaft 10 from where handle 16 is mounted to shaft 10. Length L2 may be unequal to length L1. Where length L2 is unequal to length L1 , length L2 is an offset length L3 less than length L1.

[0050] First blade 12 and second blade 14 may be connected by support 18. Support 18 extends between opposing surfaces of first blade 12 and second blade 14.

[0051] Support 18 may be shaped to minimize resistance and/or turbulence when paddle 100 is inserted into the water and/or when paddle 100 is paddled. In some embodiments, support 18 is tapered in thickness toward edge 19. Edge 19 may be a fine edge. Edge 19 may extend between first blade 12 or shaft 10 and second blade 14. Edge 19 may extend along a curve from first blade 12 to second blade 14 (see e.g. fig. 2B). For example, edge 19 may extend along a parabola from first blade 12 to second blade 14.

[0052] In some embodiments, one or more additional blades are mounted at or near second end 10B of shaft 10 instead of handle 16. For example, a third blade and a fourth blade may be mounted at or near second end 10B of shaft 10, wherein the third blade mirrors first blade 12 and the fourth blade mirrors second blade 14.

[0053] Figure 2C is a partial side view of shaft 10 and blades 12 and 14 of paddle 100. First blade 12 extends from shaft 10 substantially along first blade axis A1. Second blade 14 extends from shaft 10 substantially along second blade axis A2. Shaft 10 extends substantially along shaft axis A3. First blade 12 forms first blade angle 01 between first blade axis A1 and shaft axis A3. Second blade 14 forms second blade angle 02 between second blade axis A2 and shaft axis A3.

[0054] First blade angle 01 is unequal to second blade angle 02. In some embodiments, second blade angle 02 is greater than first blade angle 01 . For example, first blade angle 01 may be in the range of 0 degrees to 12 degrees. Second blade angle 02 may be in the range of 7 degrees to 19 degrees.

[0055] First blade 12 extends from shaft 10 by a first blade length L4 along first blade axis A1. Second blade 14 extends from shaft 10 by a second blade length L5 along second blade axis A2. In some embodiments, first blade length L4 is unequal to second blade length L5. For example, second blade length L5 may be greater than first blade length L4.

[0056] First blade 12 extends from shaft 10 by a first blade projection P1 , wherein first blade projection P1 is the length of first blade 12 parallel to shaft axis A3. Accordingly, first blade projection P1 is equal to the cosine of first blade angle 01 multiplied by first blade length L4:

[0057] Second blade 14 extends from shaft 10 by a second blade projection P2, wherein second blade projection P2 is the length of second blade 14 parallel to shaft axis A3. Accordingly, second blade projection P2 is equal to the cosine of second blade angle 02 multiplied by second blade length L5:

P₂ = L₅ x cos 0₂ (2)

[0058] In some embodiments, first blade projection P1 overlaps with second blade projection P2 by overlap length L6, wherein overlap length L6 is parallel to shaft axis A3.

[0059] In some embodiments, first blade angle 01 is a fraction of second blade angle 02, and first blade angle 01 and second blade angle 02 lie within the same arc. Where first blade angle 01 and second blade angle 02 lie within the same arc, axes A1 , A2 and A3 lie within the same plane.

[0060] Figure 2D is a partial front view of shaft 10 and blades 12 and 14 of paddle 100. Figure 2E is a partial back view of shaft 10 and blades 12 and 14 of paddle 100. First blade 12 has a first blade width W1 measured perpendicular to first blade axis A1 . Second blade 14 has a second blade width W2 measured perpendicular to second blade axis A2. First blade width W1 is the widest part of first blade 12. Second blade width W2 is the widest part of second blade 14. [0061] Shaft 10 has a shaft width W3 measured perpendicular to shaft axis A3. In some embodiments, first blade 12 tapers from first blade width W1 to shaft width W3. Second blade 14 may taper from second blade width W2 to shaft width W3.

[0062] In some embodiments, first blade width W1 is substantially equal to second blade width W2. First blade width W1 is substantially equal to second blade width W2 when first blade width W1 is within 5% of second blade width W2.

[0063] In some embodiments, axes A1 , A2 and A3 lie within plane P1 (not shown), wherein plane P1 is perpendicular to power surfaces 13 and 15.

[0064] Figure 2F is an end view of first blade 12, i.e. a view of first blade 12 along axis A1. First blade 12 has power surface 13. As depicted in figure 2F, power surface 13 of first blade 12 may curve away from shaft 10, i.e. towards the front of paddle 100. In some embodiments, power surface 13 of first blade 12 is concave.

[0065] Figure 2G is an end view of second blade 14, i.e. a view of second blade 14 along axis A2. Second blade 14 has power surface 15. As depicted in figure 2G, power surface 15 of second blade 14 may curve away from shaft 10, i.e. towards the front of paddle 100. In some embodiments, power surface 15 of second blade 14 is concave.

[0066] Power surfaces 13 and 15 are the respective surfaces of blades 12 and 14 that are drawn against the water during a paddle stroke.

[0067] Figures 2H and 2I depict blades 12 and 14 connected by support 18, wherein support 18 tapers from shaft 10 to edge 19.

[0068] Figures 3A to 3E depict a section of paddle 100 at various orientations to the surface of the water. Figures 3A to 3E depict a portion of shaft 10 and power surfaces 13 and 15 respectively of blades 12 and 14.

[0069] The surface of the water is depicted by water surface S. Paddle 100 may be at one or more of the orientations to water surface S as depicted in figures 3A to 3E during a stroke of paddle 100.

[0070] Shaft axis A3 of shaft 10 forms shaft angle o1 with water surface S. First power surface 13 forms first power surface angle <t>1 with water surface S, and second power surface 15 forms second power surface angle <t>2 with water surface S.

[0071] During a paddle stroke, paddle 100 may be stroked between any two of the orientations depicted in figures 3A to 3E. During the paddle stroke, shaft 10 rotates clockwise. As shaft 10 rotates clockwise, both power surfaces 13 and 15 also rotate clockwise.

[0072] Figure 3A depicts an orientation of paddle 100 where both of power surface angles 01 and 02 are greater than 90 degrees. Accordingly, neither of power surfaces 13 and 15 are perpendicular to water surface S. Because second blade angle 02 is greater than first blade angle 01 , second power surface angle 02 is greater than first power surface angle 01.

[0073] Figure 3B depicts an orientation of paddle 100 where first power surface angle <t>1 is equal to 90 degrees. Accordingly, first power surface 13 is perpendicular to water surface S. When first power surface 13 is perpendicular to water surface S, the amount of force on the water from first power surface 13 that is useful force is maximized.

Therefore, the amount of useful force on the water from paddle 100 is at a first maximum when first power surface 13 is perpendicular to water surface S.

[0074] Because second blade angle 02 is greater than first blade angle 01 , when first power surface angle 1 is equal to 90 degrees, second power surface angle 02 is greater than 90 degrees, as depicted in figure 3B.

[0075] Figure 3C depicts an orientation of paddle 100 where first power surface angle 01 is less than 90 degrees, and second power surface angle 02 is greater than 90 degrees. Accordingly, neither of power surfaces 13 and 15 are perpendicular to water surface S.

[0076] Figure 3D depicts an orientation of paddle 100 where second power surface angle 02 is equal to 90 degrees. Accordingly, second power surface 15 is perpendicular to water surface S. When second power surface 15 is perpendicular to water surface S, the amount of force on the water from second power surface 15 that is useful force is maximized. Therefore, the amount of useful force on the water from paddle 100 is at a second maximum when second power surface 15 is perpendicular to water surface S.

[0077] Because second blade angle 02 is greater than first blade angle 01 , when second power surface angle 02 is equal to 90 degrees, first power surface angle 01 is less than 90 degrees, as depicted in figure 3D.

[0078] Figure 3E depicts an orientation of paddle 100 where both of power surface angles 01 and 02 are less than 90 degrees. Accordingly, neither of power surfaces 13 and 15 are perpendicular to water surface S. Because second blade angle 02 is greater than first blade angle 01 , second power surface angle <t>2 is greater than first power surface angle <t>1.

Various Embodiments

[0079] In one or more embodiments of paddle 100:

• first blade angle 01 is in the range of 0 to 12 degrees; and/or

• second blade angle 02 is in the range of 7 to 19 degrees.

[0080] In one or more embodiments of paddle 100, shaft 10 is:

• in the range of 24 to 300 centimeters long along shaft axis A3;

• adjustable in length along shaft axis A3;

• in the range of 1 to 6 centimeters in diameter perpendicular to shaft axis A3;

• substantially circular in cross-section perpendicular to axis A3;

• substantially oval in cross-section perpendicular to axis A3; and/or

• tapered along axis A3 from the second end of shaft 10 to the first end of shaft 10.

[0081] In one or more embodiments of paddle 100, first blade 12 is:

• in the range of 7 to 42 centimeters long along first blade axis A1 ; and/or

• concave perpendicular to first blade axis A1 .

[0082] In one or more embodiments of paddle 100, second blade 14 is:

• in the range of 10 to 60 centimeters long along second blade axis A2; and/or

• concave perpendicular to second blade axis A2.

[0083] In one or more embodiments of paddle 100:

• L1 is in the range of 30 to 300 centimeters;

• L2 is in the range of 27.5 to 297.5 centimeters;

• L3 is in the range of 7 to 60 centimeters;

• L4 is in the range of 7 to 42 centimeters;

• L5 is in the range of 10 to 60 centimeters;

• L6 is in the range of 0 to 20 centimeters;

• W1 is in the range of 10 to 40 centimeters; and/or

• W2 is in the range of 7 to 40 centimeters.

[0084] In one or more embodiments of paddle 100: • shaft 10 comprises one or more of wood, aluminum, plastic, fiberglass, and carbon fiber;

• blade 12 comprises one or more of wood, aluminum, plastic, fiberglass, and carbon fiber; and/or

• blade 14 comprises one or more of wood, aluminum, plastic, fiberglass, and carbon fiber.

Interpretation of Terms

[0085] Unless the context clearly requires otherwise, throughout the description and the claims:

• “comprise”, “comprising”, and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”;

• “connected”, “coupled”, or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, or a combination thereof;

• “herein”, “above”, “below”, and words of similar import, when used to describe this specification, shall refer to this specification as a whole, and not to any particular portions of this specification;

• “or”, in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list;

• the singular forms “a”, “an”, and “the” also include the meaning of any appropriate plural forms.

[0086] Words that indicate directions such as “vertical”, “transverse”, “horizontal”, “upward”, “downward”, “forward”, “backward”, “inward”, “outward”, “vertical”, “transverse”, “left”, “right”, “front”, “back”, “top”, “bottom”, “below”, “above”, “under”, and the like, used in this description and any accompanying claims (where present), depend on the specific orientation of the apparatus described and illustrated. The subject matter described herein may assume various alternative orientations. Accordingly, these directional terms are not strictly defined and should not be interpreted narrowly. [0087] Where a component (e.g. a shaft, blade, handle, etc.) is referred to above, unless otherwise indicated, reference to that component (including a reference to a “means”) should be interpreted as including as equivalents of that component any component which performs the function of the described component (i.e., that is functionally equivalent), including components which are not structurally equivalent to the disclosed structure which performs the function in the illustrated exemplary embodiments of the invention.

[0088] Specific example embodiments have been described herein for purposes of illustration. These are only examples. The technology provided herein can be applied to systems other than the example systems described above. Many alterations, modifications, additions, omissions, and permutations are possible within the practice of this invention. This invention includes variations on described embodiments that would be apparent to the skilled addressee, including variations obtained by: replacing features, elements and/or acts with equivalent features, elements and/or acts; mixing and matching of features, elements and/or acts from different embodiments; combining features, elements and/or acts from embodiments as described herein with features, elements and/or acts of other technology; and/or omitting combining features, elements and/or acts from described embodiments.

[0089] Various features are described herein as being present in “some embodiments”. Such features are not mandatory and may not be present in all embodiments. Embodiments of the invention may include zero, any one or any combination of two or more of such features. This is limited only to the extent that certain ones of such features are incompatible with other ones of such features in the sense that it would be impossible for a person of ordinary skill in the art to construct a practical embodiment that combines such incompatible features. Consequently, the description that “some embodiments” possess feature A and “some embodiments” possess feature B should be interpreted as an express indication that the inventors also contemplate embodiments which combine features A and B (unless the description states otherwise or features A and B are fundamentally incompatible).

[0090] It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions, omissions, and sub-combinations as may reasonably be inferred. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

Claims

CLAIMS:

1 . A paddle comprising: a shaft extending along a shaft axis, wherein the shaft has a first end and an opposing second end; a first blade extending from the first end of the shaft and at a first blade angle to the shaft axis; and a second blade extending from the shaft at a second blade angle to the shaft axis, wherein the second blade angle is unequal to the first blade angle.

2. The paddle of claim 1 , wherein the second blade extends from the shaft between the first end and the second end.

3. The paddle of either of claims 1 or 2, wherein the second blade angle is greater than the first blade angle.

4. The paddle of any one of claims 1 to 3, wherein: the first blade extends from the shaft by a first blade length; the second blade extends from the shaft by a second blade length; and the second blade length is greater than the first blade length.

5. The paddle of claim 4, wherein the second blade extends from the shaft at an offset length from the first end of the shaft, and the offset length is less than the second blade length.

6. The paddle of claim 5, wherein the offset length is less than a second blade projection, wherein the second blade projection is equal to a cosine of the second blade angle multiplied by the second blade length.

7. The paddle of any one of claims 1 to 6, further comprising a support extending from the first blade to the second blade.

8. The paddle of claim 7, wherein the support extends from the shaft to an edge, the edge extends from the first blade to the second blade, and the support tapers from the shaft to the edge.

9. The paddle of claim 8, wherein the edge extends along a curve.

10. The paddle of any one of claims 1 to 9, wherein: the first blade has a first blade width perpendicular to the first blade length; the second blade has a second blade width perpendicular to the second blade length; and the first blade width is substantially equal to the second blade width.

11 . The paddle of claim 10, wherein the first blade width is between 5% wider than the second blade width and 5% narrower than the second blade width.

12. The paddle of either of claims 10 and 11 , wherein the first blade is concave along the first blade width away from the shaft axis.

13. The paddle of any one of claims 10 to 12, wherein the second blade is concave along the second blade width away from the shaft axis.

14. The paddle of any one of claims 1 to 13, wherein the first blade angle and the second blade angle lie within an arc.

15. The paddle of any one of claims 1 to 14, wherein: the first blade extends from the shaft along a first blade axis; the second blade extends from the shaft along a second blade axis; and the first blade axis, the second blade axis and shaft axis lie within a plane.

16. The paddle of any one of claims 1 to 15, wherein the first blade angle is in the range of 0 degrees to 12 degrees.

17. The paddle of any one of claims 1 to 16, wherein the second blade angle is in the range of 7 degrees to 19 degrees.

18. The paddle of any one of claims 1 to 17, wherein the paddle comprises a handle attached to the second end of the shaft.

19. A paddle comprising: a shaft extending along a shaft axis, wherein the shaft has a first end and an opposing second end; a first power surface extending from the first end of the shaft and at a first surface angle to the shaft axis; and a second power surface extending from the shaft above the first power surface and at a second surface angle to the shaft axis, wherein the second surface angle is unequal to the first surface angle.

20. The paddle of claim 19, wherein the second surface angle is greater than the first surface angle.

21. The paddle of either of claims 19 and 20, wherein the first power surface is provided by a first blade, and the second power surface is provided by a second blade.

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