GB2443676A - Manual boat propulsion system - Google Patents

Abstract

A watercraft 1 is powered by a user 3 sitting on a sliding seat 4 and using footrests 7 and 8. The user operates a rowing mechanism which may have a handle 10, cord 11 and reel 12. Power is transmitted through the rowing mechanism to a series of paddles (20, Fig 2) which move in a loop in a horizontal plane through the water underneath the watercraft. The paddles may be mounted on a belt (19, Fig 2) which may pass around front and rear wheels (17, 18, Fig 2). The paddles may be feathered when moving forwards, by means of followers (25, Fig 4b) and a cam surface (27, Fig 4a).

Description

Watercraft Propulsion System This invention relates to a system for the

propulsion of watercraft.

Rowing is a popular method of propelling a boat, in which the rower transmits effort by means of oars. However, it has a number of disadvantages. Skill is required for the successful manipulation of the oars, and considerable skill is required to handle boats designed to travel at higher speeds, such as sculls. Significant training is required before a single scull, for example, can be used effectively. In a conventional rowing boat, the rower does not face the direction of travel, making it necessary to turn round at intervals, which is uncomfortable and can spoil the enjoyment to an extent as well as raising safety issues. It is also difficult to transmit the rower's muscle power effectively. A trained oarsman can transmit power effectively, and in such cases rowing is one of the most healthy forms of exercise for all the muscle groups. However, an inexperienced rower will find it difficult to exercise effectively when rowing a boat.

According to one aspect of the present invention, there is provided a watercrafi having a bow and a stem, a seat and a footrest arranged for an operator to sit facing the bow, a simulated rowing mechanism for use by an operator sitting on the seat and holding at least one member of the simulated rowing mechanism, a rotatable drive member arranged for rotation at least during power strokes in which the operator pulls the member towards the operator's body, and water engaging propulsion means connected to the drive member so as to propel the watercrafl forwards at least during the power strokes.

According to another aspect of the present invention, there is provided a method of propelling a watercraft through water, the watercraft having a bow, a stem, and a seat, the method comprising the steps of sitting on the seat facing the bow, holding at least one member of a simulated rowing mechanism, and operating the member so as to rotate a drive member at least during power strokes in which the member is pulled towards the body, the drive member being connected to water engaging propulsion means so as to propel the watercraft forwards at least during the power strokes.

According to another aspect of the present invention, there is provided a watercraft having a bow and a stern, a seat and a footrest arranged for an operator to sit facing the bow, a reel, a flexible element attached to and wound around the reel, a handle attached to the flexible element whereby an operator can rotate the reel in a first sense by pulling on the handle in a power stroke, a return mechanism causing the reel to turn in the opposite sense and the flexible element to be re- wound onto the reel whilst the operator permits the handle to move in a return direction in a return stroke, a rotatable drive member coupled to the reel so that the drive member is rotated during the power stroke, and water engaging propulsion means connected to the drive member so as to propel the watercraft forwards during the power stroke.

Thus, in use an operator can sit on the seat facing forwards, position his feet on the footrest, grasp the handle, and perform a simulated rowing action with power strokes and return strokes, thus propelling the watercraft forwards. Preferably the seat is a sliding seat on rails, to enhance the rowing action. The footrest may be used for steering, with pressure on the left or right foot, or sideways movement of a foot, causing a rudder to turn the boat in the appropriate direction. The footrest may be a single member, or separate members for each foot.

Means must be provided so that the watercraft is propelled forwards during the power stroke, but is not propelled backwards during the return stroke. Thus, a uni-directional coupling such as a ratchet could be used. Preferably, this is positioned between the reel and the drive member, although it could be positioned elsewhere such as between the drive member and the propulsion means. The propulsion means itself could be such that it operates only in one direction.

The propulsion means is preferably such that it is "feathered" when it is not driving, i.e. during the return stroke, to reduce friction whilst the watercraft is gliding forwards before the next power stroke. Alternatively, the arrangement could be such that the propulsion means continues to be driven during the return stroke. Thus, the reel could be connected to a flywheel which stores energy which is used to drive the propulsion means. Gearing could be provided so that the speed of rotation of the flywheel is greater than that of the reel. Further gearing could be provided so that the propulsion means is driven at an appropriate speed. In general, whatever configuration is used, gearing may be provided as appropriate.

The propulsion means could be one or more paddles, propellers or other known arrangement which can convert rotational drive into a propulsive force.

The reel may be organised in any desired plane, for example horizontal or vertical, and this may depend on the general layout of the watercraft and the means of propulsion. For example, if laterally arranged paddle wheels are provided, rotatable about a horizontal axis, the reel may also be disposed with its axis horizontal.

In one preferred arrangement, the propulsion means comprises a series of paddles underneath the hull of the watercraft which move in a horizontal plane, and the reel is disposed with its axis extending vertically.

It will be appreciated that the expressions "vertical" and "horizontal" are not meant to be construed in a strict geometric sense.

The watercraft may take any suitable form for human propulsion. Whilst the preferred configuration has the general form of a rowing boat, other forms are possible such as a simple board such as a surfboard or sailboard, a pair of floats with a platform or the like -such as in a "pedalo" -a raft and so forth.

A brake may be provided, which can act on any part of the drive mechanism to prevent the propulsion means from operating. For example, in an arrangement with a flywheel a friction brake could act on that. In the case of propulsion means which can operate in both directions, means may be provided to drive it in the reverse direction. There could, for example, be a coupling or gearing between the reel and the remainder of the drive mechanism, which reverses the direction of drive although of course the power stroke will still rotate the reel in the same direction.

Alternatively, there could be an auxiliary arrangement for driving the propulsion means in the reverse direction such as a rotatable handle or the like.

It will be appreciated that there are other mechanisms for simulating rowing, which could also be used to drive the propulsion means, including arrangements in which the operator moves rigid members to simulate the operation of oars. Such movement can be converted into rotary motion and also used to drive the propulsion means. In some arrangements, the operator could power the propulsion means during both the power stroke and the return stroke.

An embodiment of the invention will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a plan view of a boat embodying the invention; Figure 2 is a plan view showing the drive wheels of the propulsion mechanism; Figure 3 (a) is a plan view of the drive mechanism in greater detail; Figure 3(b) is a view of a paddle; Figure 4 (a) is a plan view of an alternative drive mechanism; Figure 4(b) is a side view of a paddle in this alternative arrangement; Figure 4(c) is a front view of a paddle in this alternative arrangement; and Figure 5 is a partial transverse section through the boat showing part of the drive mechanism of Figure 4 (a).

Referring now to Figure 1, there is shown a boat 1 having a hull 2. Within the hull 2, an operator 3 sits on a sliding seat 4 mounted on longitudinal rails 5, facing the bow 6 of the boat. The feet of the operator rest of foot rests 7 and 8, which are movable so as to control a rudder 9 at the stern of the boat by means of cables.

The operator is holding a transverse handle 10 which is attached to a cord Ii, itself attached to a reel 12 which is mounted for rotation about a vertical axis. A return spring mechanism is provided, as well as a ratchet arrangement. Thus, on the power stroke in which the operator pulls the handle 10, the reel 12 provided rotary drive.

During the return stroke, the cord is would up on the reel and the ratchet arrangement prevents reverse drive. During the return stroke the seat 4 slides towards the bow of the boat, and during the power stroke the seat 4 slides towards the stern of the boat.

Figure 2 shows how a drive shaft 13 which receives rotary drive from the reel 12 is connected to a first pulley or gear wheel 14, which in turn drives a smaller second pulley or gear wheel 15 by means of a belt or chain 16. A gear train could be incorporated if desired. The second pulley or gear wheel 15 is mounted coaxially with a first drive wheel 17, coupled to a second drive wheel, or slave drive wheel, 18 by a belt 19. Both drive wheels rotate about vertical axes, and the second drive wheel is spaced from the first drive wheel in the longitudinal direction of the boat, towards the stern.

The belt 19 carries paddles 20 which are described in more detail with reference to Figures 3 (a) and (b). The paddles are operative along the centre line of the boat, and adopt a feathered state during return when they are towards the outside of the boat.

In an alternative arrangement, the paddles could be out of the water in the return phase and in that arrangement the axes of the various rotatable members would be horizontal rather than vertical.

With reference to Figures 3 (a) and (b), each paddle 20 is flat and generally rectangular. The paddles 20 are made of wood, plastic, metal or any suitable material. The precise number and size depends on the use of the boat, i.e. the force likely to be applied by the operator. They could be flat or curved, to engage the water more effectively. There is a system, described below, so that they only push the water when moving in one direction although the same effect could be obtained in a number of ways.

As shown in Figures 3(a) and (b), each paddle 20 is mounted pivotally on the belt 19, on a vertical, central axis, and is provided with a wheel 21 or like follower element at both ends. Extending along the boat are a pair of guide rails 22 and 23, which are parallel for most of their length and diverge at their ends. As each paddle leaves the region of the first drive wheel 17, the outermost wheel 21 is received between the lateral guide rails 22 and 23, and urges the paddle 20 to an orientation which is perpendicular to the intended direction of travel. The paddle then pushes on the water as it moves down the guide rails. Adjacent the second drive wheel 18, the outermost wheel 21 leave the guide rails 23 and 23. The paddle 20 is then free to move and will adopt an orientation generally parallel to the direction of travel. The paddle stays in that orientation until it completes its return path to the first drive wheel 17.

Figures 4 (a), (b) and (c) and 5 show an alternative arrangement, in which belt 19 is provided with paddles 24. Instead of being pivotally attached to the belt for rotation about a vertical axis, the paddles are mounted for rotation about a horizontal axis. A wheel or other follower 25 is provided, but as shown in Figures 4 (b), 4 (c) and 5, this is displaced rearwardly from the blade of the paddle by a member 26 extending perpendicularly from the blade. Instead of the wheel 25 being received between lateral guide rails as in the previous embodiment, it engages a longitudinal cam surface 27 arranged above the paddles, extending from the first drive wheel 17 to the second drive wheel 18. At its ends this cam surface 27 is curved away from the drive wheels in the vertical plane. Thus, as a paddle 24 leaves the first drive wheel 17, downward pressure is applied to the follower wheel 25 by the cam surface 27 causing the paddle to be pivoted downwards so as to be perpendicular to the direction of intended travel. As the paddles 24 reach the second drive wheel 18, they are free to pivot so as to lie in a horizontal orientation parallel to the direction of travel.

As shown in Figure 5, the cam surface 27 is provided on a bottom portion of the hull 2ofthe boat.

There is thus provided an effective method of propelling a boat, in which an operator simulates a rowing action, and the effort of the operator is converted firstly to rotary motion and then to horizontal movement of paddles to drive the boat through the water.

It will be appreciate that the paddle mechanism per se may be used to propel a watercraft that is powered by an arrangement other than that described above, which involves a simulated rowing mechanism. The invention therefore extends to aspects of the paddle mechanism also.

Thus, for example, according to a further aspect of the present invention, there is provided a paddling mechanism having a first drive wheel coupled to a second drive wheel by a belt or chain or similar wherein both drive wheels lie in substantially the same horizontal plane and pivot about vertical axes; a series of paddles, attached to the belt at intervals; a pivot on each paddle, permitting the primary surface of the paddle to be normal to the direction of motion of the belt or parallel thereto; and a mechanism for moving the paddles between these two orientations, operable such that the paddles moving from the first drive wheel towards the second are substantially in one orientation, and the paddles moving from the second drive wheel towards the first are substantially in the other.

This paddling mechanism might be attached to a water craft such that only those paddles travelling from the primary drive wheel to the secondary drive wheel engage with the water lying under the craft, so as to propel the craft through the water. It will be understood that any source of rotary force could be used to power such a mechanism. This aspect of the invention is not limited to the rotary force being provided by a simulated rowing action; it could, for example, be powered by an internal combustion engine.

Claims (12)

1. A watercraft having a bow and a stem, a seat and a footrest arranged for an operator to sit facing the bow, a simulated rowing mechanism for use by an operator sitting on the seat and holding at least one member of the simulated rowing mechanism, a rotatable drive member arranged for rotation at least during power strokes in which the operator pulls the member towards the operator's body, and water engaging propulsion means connected to the drive member so as to propel the watercraft forwards at least during the power strokes.

2. A watercraft as claimed in claim 1, wherein the simulated rowing mechanism comprises a reel, a flexible element attached to and wound around the reel, a handle attached to the flexible element and constituting said at least one member of the simulated rowing machine, and a return mechanism causing the reel to turn in the opposite sense and the flexible element to be re-wound onto the reel whilst the operator causes the handle to move in a return direction in a return stroke, and wherein the rotatable drive member is coupled to the reel.

3. A watercraft as claimed in claim 2, wherein a one way drive mechanism disconnects the reel from the rotatable drive member during the return stroke.

4. A watercraft as claimed in any claim 2, wherein the arrangement is such that the propulsion means continues to be driven during the return stroke.

5. A watercraft as claimed in claim 4, wherein the reel is connected to a flywheel which stores energy from the power stroke which is used to drive the propulsion means during the return stroke.

6. A watercraft as claimed in any preceding claim, wherein the footrest is arranged for steering the watercraft.

V

7. A watercraft as claimed in any preceding claim, wherein the seat is a sliding a seat.

8. A watercraft as claimed in any preceding claim, wherein the water engaging propulsion means comprises a rotatable propeller or paddle.

9. A watercraft as claimed in any of claims Ito 7, wherein the propulsion means comprises a series of paddles underneath the hull of the watercraft which move in a horizontal plane.

10. A watercraft as claimed in claim 9, wherein the paddles move in a Continuous loop between a pair of wheels spaced longitudinally of the watercraft, and the arrangement is such that when the paddles move in the forwards direction they are feathered.

11. A watercraft as claimed in claim 10, wherein feathering of a paddle is effected in accordance with the engagement of a cam follower with a cam surface.

12. A watercraft, substantially as hereinbefore described with reference to the accompanying drawings.