FIELD OF THE INVENTION
The present invention relates to watercraft and more particularly to pedal boats.
BACKGROUND OF THE INVENTION
Pedal boats are typically simple watercraft with a paddlewheel that is driven manually by one or more riders through one or more sets of pedals. This type of watercraft is typically relatively inexpensive and does not require fuel, thereby avoiding an inconvenience associated with motorboats. Additionally, a pedal boat provides the user with some exercise so that the boating experience for the user is not sedentary.
There are several disadvantages associated with pedal boats, however. One such disadvantage is that the user typically cannot travel very far in a pedal boat, in part because the user must take into account that they have to pedal the boat back to their departure point. Another disadvantage is that pedal boats are typically relatively inefficient in terms of energy consumption relative to the amount of forward movement generated thereby.
While it is possible to overcome the problem of restricted travel distance by installing an outboard motor on a pedal boat, this can have some drawbacks associated therewith. One such drawback is that the movement of the boat in the water while powered by the motor causes the pedals to rotate, which can injure a boat rider if their foot is in the swept path of the pedals.
SUMMARY OF THE INVENTION
In a first aspect, the invention is directed to a watercraft that is drivable by a manual force input member and by a motor. The watercraft is configured to prevent the motor from back-driving the manual force input member.
In a particular embodiment, the watercraft includes a hull, a propelling member configured to propel the hull through water, a manual force input member that is movable manually, an output shaft that is operatively connected to the propelling member and that is drivable by the manual force input member, a motor that is operatively connectable to the output shaft, and a one-way clutch connected between the manual force input member and the output shaft. The one-way clutch is configured to permit the manual force input member to drive the output shaft in a first rotational direction, and to prevent the output shaft from driving the manual force input member in the first rotational direction.
In a second aspect, the invention is directed to a watercraft that is drivable by a manual force input member and by a motor, wherein a torque sensor is configured to send signals to a controller related to the amount of torque being transmitted from the manual force input member, wherein the controller is configured to control the motor based on the signals sent to the controller by the torque sensor.
In a second aspect, the invention is directed to a torque sensor, comprising a first support member that is rotatably drivable by a first rotating member, at least one first trip member mounted to the first support member, a first sensor configured for sending first sensor signals to a controller when sensing the presence of the first trip member, a second support member that is rotatable, at least one first trip member mounted to the first support member, a second sensor configured for sending second sensor signals to the controller when sensing the presence of the second trip member, a spring operatively connecting the first support member to the second support member. The controller is configured to determine the torque exerted between the first and second support members based on the time delay between the first and second sensor signals.
In a fourth aspect, the invention is directed to a watercraft that is drivable in a plurality of modes controlling the amount of electric motor assist that is available in addition to driving the watercraft with a manual force input member. In a first mode, the watercraft is drivable by the manual force input member with no electric motor assist. In a second mode, at least some electric motor assist is provided. Optionally the second mode includes a setting wherein the watercraft is drivable substantially unilaterally by the electric motor assist, ie. without the manual force input member.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described by way of example only with reference to the attached drawings, in which:
FIG. 1 is an elevation view of a watercraft in accordance with an embodiment of the present invention;
FIG. 2 is a plan view of a drive train that is part of the watercraft shown in FIG. 1;
FIG. 3
a is a perspective view of a portion of the drive train shown in FIG. 2;
FIG. 3
b is a sectional elevation view of the portion of the drive train shown in FIG. 3a, showing a control pin for a clutch bypass mechanism in a bypass position;
FIG. 3
c is a sectional elevation view of the portion of the drive train shown in FIG. 3a, showing the control pin for the clutch bypass mechanism in a non-bypass position;
FIG. 4 is a perspective view of a portion of the drive train shown in FIG. 2;
FIG. 5 is a sectional elevation view of the portion of the drive train shown in FIG. 4;
FIG. 6 is a magnified elevation view of a portion of the drive train shown in FIG. 4;
FIG. 7 is a perspective view of a torque sensor shown in FIG. 6;
FIG. 8 is a sectional elevation view of a portion of the drive train shown in FIG. 2;
FIG. 9 is an optionally configured control lever for use with the drive train shown in FIG. 2;
FIG. 10 is an elevation view of the watercraft shown in FIG. 1 with an alternative layout for driving the propelling member that propels the watercraft;
FIG. 11 is an elevation view of the watercraft shown in FIG. 1 with another alternative layout for driving the propelling member;
FIG. 12 is an elevation view of the watercraft shown in FIG. 1 with yet another alternative layout for driving the propelling member; and
FIG. 13 is a perspective view of a portion of a layout for driving the propelling member.
DETAILED DESCRIPTION OF THE INVENTION
Reference is made to FIG. 1, which shows a watercraft 10, in accordance with an embodiment of the present invention. The watercraft 10 includes a hull 12 and a drive train 14. In the embodiment shown in FIG. 1, the watercraft 10 is a pedal boat. The hull 12 may have any suitable configuration and may have any suitable number of seats. In the example shown in FIG. 1, the hull 12 is equipped with four seats 16, two seats 16 in a front row and two in a back row. In FIG. 1, only one of the front row seats 16 and one of the back row seats 16 are visible since they obscure the other seats in their respective rows. It is alternatively possible for the hull 12 to be configured with more or fewer seats, and could have as little as one seat thereon.
The drive train 14 includes a propelling member 18, two manual force input members 20 (shown individually at 20a and 20b), two one-way clutches 22 shown in FIG. 5 and shown individually at 22a and 22b, two clutch bypass mechanisms 23 shown in FIG. 5 and shown individually at 23a and 23b, a motor 24 (FIG. 2), a gearbox 25, a motor engagement clutch 26 and a torque sensor 28 (FIG. 5).
The propelling member 18 may be any suitable type of propelling member for propelling the watercraft 10 in water. For example, the propelling member 18 may be a propeller, as shown in the figures. As an alternative example, the propelling member may be a paddlewheel.
The manual force input members 20a and 20b may have any suitable structure and together drive a common shaft 29. More specifically, the first manual force input member 20a drives a first end 29a of the common shaft 29 either through the first one-way clutch 22a or through the first clutch bypass mechanism 23a, and the second manual force input member 20b drives a second end 29b of the common shaft 29 either through the second one-way clutch 22b or through the second clutch bypass mechanism 23b.
In the embodiment shown in FIG. 2, each manual force input member 20 is a pedal-and-sprocket arrangement made up of two pedals 30 which drive the rotation of a first sprocket 32, wherein a toothed belt 34 connects the first sprocket 32 to a second sprocket 36. It will be understood that the toothed belt 34 could alternatively be a chain or other similar element. It will further be understood that the toothed belt 34 and the first and second sprockets 32 and 36 could be replaced in some embodiments by a non-toothed belt and pulleys.
A controller 118 is provided in communication with the motor 24 for controllably adjusting the speed of the motor 24, and thus the rotational speed of the propelling member 18. The controller 118 is also in communication with a boat speed sensor 122. The boat speed sensor 122 is, by way of several specific and non-limiting examples, one of a Global Positioning System (GPS) based speed sensor, a drag sensor or a turbine driven sensor. During use, an algorithm correlates the speed of the propelling member 18 and the speed of the watercraft 10. A maximum deviation from the theoretical correct propeller speed is pre-defined, and the algorithm ensures that the propeller revolution speed remains within the pre-defined tolerance range. In this way, the propeller is prevented from turning at a speed that is either unnecessarily high or unnecessarily low. Accordingly, the algorithm ensures that the propelling member 18 works in its highest efficiency range. In an embodiment, the algorithm is embedded in the motor controller software of controller 118.
The second sprocket 36, the one-way clutch 22a and the clutch bypass mechanism 23a are shown further in FIGS. 3a, 3b and 3c. As shown, the second sprocket 36 is made up of a toothed member 38 and an extension member 40 which are fixedly joined together by bolts 42.
One-way clutch 22a connects between the extension member 40 and the common shaft 29. The one-way clutch 22a may be any suitable type of one-way clutch such as an INA needle roller one-way clutch. The one-way clutch 22a has an outer race 46, an inner race 48 and a plurality of rollers 50 therebetween. The outer race 46 is connected to the extension member 40 of the second sprocket 36. The inner race 48 is connected to the common shaft 29, for example by a key 52. The rollers 50 are configured so that one-way clutch 22a permits the sprocket 36 to transfer torque to the common shaft 29 when being driven forward (i.e., in the direction of arrow 54 in FIG. 3a). Thus, the one-way clutch 22a permits a boat rider, shown at 56 in FIG. 1, to transfer torque to the common shaft 29 when pedaling forward (ie. clockwise in the view shown in FIG. 1). However, the rollers 50 are configured so that the one-way clutch 22a will not permit the common shaft 29 to transfer torque to the sprocket 36 when rotated in the direction of arrow 54.
As a result of the above, in a situation where the second sprocket 36 is rotating forward at any speed faster than the common shaft 29, the rollers 50 are brought forward and torque is transferred from the second sprocket 36 to the common shaft 29. In a situation where the common shaft 29 is rotating forward at any speed faster than the second sprocket 36, the rollers 50 are brought backwards and no torque is transferred from the common shaft 29 to the second sprocket 36.
Another feature of one-way clutch 22a is that the rollers 50 prevent torque to be transferred from the second sprocket 36 to the common shaft 29 if the second sprocket 36 is rotated backwards (i.e., in the direction of the arrow shown at 58 in FIG. 3a). Also, if the common shaft 29 is driven backwards (i.e., in the direction of arrow 58), the rollers 50 permit torque to be transferred from the common shaft 29 to the second sprocket 36.
The clutch bypass mechanism 23a includes a control pin 60, a control pin actuator 61, and a plurality of drive balls 62. The control pin 60 is movable between a bypass position (FIG. 3b) and a non-bypass position (FIG. 3c). In the bypass position (FIG. 3b), the balls 62 are captured between pockets 64 in the extension member 40 of the second sprocket 36 and pockets 66 in the common shaft 29. As a result, the balls 64 transfer torque from the second sprocket 36 to the common shaft 29 regardless of which direction the second sprocket 29 rotates in. It will be noted that the pockets 66 on the common shaft 29 are open at their radially inner ends. As such the balls 62 ride on a portion of the control pin 60 which has a radius selected to ensure that the balls 62 engage the pockets 64 in the extension member 40. The portion of the control pin 60 on which the balls 62 ride when the control pin 60 is in the bypass position is referred to as the bypass portion 67.
When the control pin 60 moves to the non-bypass position (FIG. 3c), a non-bypass portion 68 of the control pin is axially aligned with the pockets 64 and 66. With the control pin 60 thus positioned, when the sprocket 36 rotates the rollers 50 in the one-way clutch 22a either rotate out of the way, or rotate into engagement, depending on the direction of rotation of the sprocket 36. In either case, the sprocket 36 and common shaft 29 are driven out of phase and so the pockets 64 become misaligned with the pockets 66. As this happens, the balls 62 get driven inwardly so that they reside partially in the pockets 66 and the clearance space provided by the non-bypass portion 68. As a result, no torque is transferred between the sprocket 36 and the common shaft 29 through the balls 62, regardless of the direction of rotation of the sprocket 36.
When the control pin actuator 61 attempts to move the control pin 60 back to the bypass position (FIG. 3b), initially it may be prevented if the pockets 64 are misaligned with the pockets 66. As the sprocket 36 is rotated, however, and the pockets 64 align with the pockets 66, the balls 62 are urged outwards into the pockets 64 by the axial force on the control pin 60 from the control pin actuator 61, which drives the balls 62 up a ramp section 70 of the control pin 60 to the bypass portion 67.
A control pin biasing member 72 may be provided to bias the control pin 60 to the non-bypass position. The biasing member 72 may be any suitable type of biasing member, such as a compression spring.
The control pin actuator 61 includes an actuator cable 74, an actuator lever 76 and an actuator lever biasing member 78. The actuator lever 76 is pivotably connected at one end to a frame member 80 and is operatively connected at an intermediate point to the control pin 60. The actuator lever 76 is movable by means of the actuator cable 74, between a non-bypass position (not shown) and a bypass position (FIG. 3a). In the non-bypass position the actuator lever 76 is retracted, and the control pin 60 is withdrawn from the common shaft 29 to its non-bypass position shown in FIG. 3c. In the bypass position (FIG. 3a), the actuator lever 76 is advanced towards the common shaft 29 and the control pin 60 is advanced further into the common shaft 29. The actuator lever biasing member 78 biases the actuator lever 76 towards the non-bypass position. Thus, the actuator lever biasing member 78 and the control pin biasing member 72 (FIG. 3c) cooperate together to bias the control pin 60 and the actuator lever biasing member 78 to their respective non-bypass positions. It is alternatively possible for one of the two biasing members 72 and 78 to be eliminated and for the remaining biasing member 72 or 78 to perform the task of biasing both the control pin 60 and the actuator lever 76 to their respective non-bypass positions.
Reference is made to FIG. 4. The actuator cable 74 is operatively connected to the actuators 61 on both the first and second clutch bypass mechanisms 23a and 23b. More specifically, the actuator cable 74 has a sheath 85 thereon that is connected to the actuator 61 on the first clutch bypass mechanism 23a. The actuator cable 74 is connected at a first end 86 to the actuator 61 on the second clutch bypass mechanism 23b. The actuator cable 74 is connected at a second end 87 to a control lever 88, which is used to pull the actuator cable 74. When the rider 56 (FIG. 1) moves the control lever 88 (FIG. 4) to a bypass position (FIG. 4), the actuator cable 74 itself urges the actuator 61 forward on the second bypass mechanism 23b. Additionally, the movement of the actuator cable 74 urges the sheath 85 to move the actuator 61 forward on the bypass mechanism 23a. The cable 74 and sheath 85 cooperate together in a manner similar to the cable and sheath of a side pull brake system on a bicycle.
It will be noted that the control lever 88 is connected to the actuator cable 74 through a tensioning member 90, which may be, for example, a compression spring. When the control lever 88 is moved to the bypass position, the actuator cable 74 is not immediately movable because the control pin 60 (FIG. 3c) on each of the bypass mechanisms 23 is prevented from moving until the pockets 64 in the extension member 40 align with the pockets 66 in the common shaft 29. Once the pockets 64 and 66 are aligned at both ends 29a and 29b (FIG. 5) of the common shaft 29, force from the tensioning member 90 (FIG. 4) drives the control pin 60 on each of the bypass mechanisms 23, forward to its bypass position (FIG. 3b).
Thus, when the control lever 88 is moved to its bypass position, both clutch bypass mechanisms 23a and 23b are actuated to bypass both one-way clutches 22a and 22b (FIG. 5) so that the common shaft 29 can be driven in both rotational directions by both manual force input members 20 (FIG. 2). Thus, the clutch bypass mechanisms 23a and 23b permit the watercraft 10 to be pedaled backwards by the rider 56 if desired.
FIGS. 3
a-3c show the first one-way clutch 22a, the first clutch bypass mechanism 23a, and the sprocket 36 associated therewith at the first end 29a of the common shaft 29. Referring to FIG. 5, it can be seen that the second one-way clutch 22b, the second clutch bypass mechanism 23b and the sprocket 36 associated therewith at the second end 29b of the common shaft 29 are similar but mirror images of those components at the first end 29a.
Reference is made to FIG. 6. The common shaft 29 is supported proximate its middle by two bearings shown at 92 and 94. Between the two bearings 92 and 94 is a first helical gear 96, which engages a second helical gear 98 that is on an output shaft 100. The first helical gear 96 is not keyed to the common shaft 29. Instead it is connected to the common shaft 29 by means of the torque sensor 28. The torque sensor 28 senses the torque transferred to the first helical gear 96 from the common shaft 29. The torque sensor 28 includes a first support member 102 that is keyed to the common shaft 29, a second support member 104 that is connected to the first helical gear 96 and a torsion spring 106. Referring to FIG. 7, the torsion spring 106 is engaged at its first end shown at 108 with the first support member 102 and is engaged at its second end shown at 110 with the second support member 104. It will be noted that the second support member 104 appears to be two separate components that are unengaged with each other in FIG. 6, however it is a single component, as shown in FIG. 7.
As shown in FIG. 6 a plurality of first magnets 112 are housed at selected positions in a ferrite ring 113 on the first support member 102, and a plurality of second magnets 114 are shown at selected positions in a ferrite ring 115 on the second support member 104. A first sensor 116 signals controller 118 when it detects the magnets 112 as they pass by it during rotation of the common shaft 29. A second sensor 120 signals the controller 118 when it detects the magnets 114 as they pass by it during rotation of the common shaft 29. The angular offset between the first and second magnets 112 and 114 affects the time delay that is present between the first and second signals sent from the first and second sensors 116 and 120 to the controller 118. Thus, the controller 118 can determine the amount of angular offset that is present between the first magnets 112 and the second magnets 114 based on the time delay between the first and second signals.
When a torque is exerted from the common shaft 29 to the first helical gear 96 there is some flexure of the torsion spring 106. The amount of flexure of the torsion spring 106 is related to the amount of torque exerted. The amount of flexure of the torsion spring 106 directly affects on the rotational positions of the first support member 102 and second support member 104 relative to each other, and thus directly affects the angular offset between the magnets 112 and 114. The controller 118 can thus determine the torque exerted from the common shaft 29 to the first helical gear 96 based on the time delay between the first signals and the second signals. Based on the torque calculated by the controller 118, and the speed of watercraft 10 as sensed by speed sensor 122, the controller 118 selects an additional torque to be exerted on the output shaft 100 by the motor 24 (FIG. 2).
It will be noted that the first magnets 112 could alternatively be any suitable type of first trip member and the first sensor 116 would be configured to sense the presence of the first trip member. Similarly the second magnets 114 could alternatively be any suitable type of second trip member and the second sensor 120 would be configured to sense the presence of the second trip member. Additionally, the torsion spring 106 could alternatively be any other suitable kind of spring that operatively connects between the first and second support members 102 and 104.
Reference is made to FIG. 8, which shows the motor 24, the gearbox 25 and the motor engagement clutch 26. The motor 24 may be any suitable type of motor. For example, the motor 24 may be a radial flux, unidirectional electric motor. The motor 24 has an output shaft 200 that is the input for the gearbox 25. In the embodiment shown the gearbox 25 is a planetary gearbox and so the output shaft 200 of the motor 24 has a sun gear 201 thereon for the gearbox 25. The planetary gearbox 25 has output members shown at 202, which drive the input side (shown at 204) of the clutch 26. The input side 204 of the clutch 26 is selectively engageable with the output side of the clutch 26, shown at 206. The clutch 26 may be any suitable type of clutch, such as a dog clutch as shown in FIG. 8. In the embodiment shown, the output side 206 is keyed to the output shaft 100, and is slidable along the output shaft 100. The output side 206 is movable by the control lever 88 between an engaged position (shown in FIG. 8) wherein the output side 206 is driven by the input side 204 through a set of dogs 208, and an unengaged position wherein the output side 206 is not driven by the input side 204. The output of the clutch 26 is the output shaft 100.
In an embodiment, the amount of additional torque to be added by the motor 24 to the output shaft 100 is selectable by the rider 56 (FIG. 1). For example, the control lever 88 shown in FIG. 9 includes optional push buttons 124 and 126 thereon for raising and lowering the amount of additional torque for the motor 24 (FIG. 2) to add to the torque provided on the first helical gear 96 (FIG. 6) by the rider 56 (FIG. 1). A display 127 showing the torque setting may be provided on the control lever 88. For example, at a first setting (eg. setting 1, as shown in FIG. 9), the controller 118 (FIG. 2) may be configured to operate the motor 24 (FIG. 2) to add 25% of the torque developed manually by the rider 56 to the output shaft 100. In other words, if the controller 118 determines that the rider 56 is driving the first helical gear 100 with 1 ft-lb of torque, then the controller 118 will operate the motor 24 to add another 0.25 ft-lbs of torque to the output shaft 100.
At a second setting on the control lever 88, the controller 118 may be configured to operate the motor (FIG. 2) to add 50% of the torque developed manually by the rider 56 to the output shaft 100. At a third setting on the control lever 88, the controller 118 may be configured to operate the motor (FIG. 2) to add 75% of the torque developed manually by the rider 56 to the output shaft 100. At a fourth setting on the control lever 88, the controller 118 may be configured to operate the motor (FIG. 2) to add 100% of the torque developed manually by the rider 56 to the output shaft 100. It will be understood that the number of settings and the torque added by the motor 24 at each setting may differ in different embodiments of the invention.
At a fifth setting the controller 118 may drive the output shaft 100 using substantially only the motor 24. This is achieved by operating the motor 24 at a sufficiently high torque level that the motor 24 will drive the output shaft 100 at a relatively high speed. In doing so, the motor 24 will also drive the first helical gear 96 by means of the second helical gear 98. In turn the first helical gear 96 will drive the common shaft 29 at a relatively high speed. The relatively high speed may be selected to be sufficiently high that if the rider 56 (FIG. 1) attempts to pedal, he or she will not be able to match the speed of the common shaft 29. As a result, of the relatively higher speed of the common shaft 29, the rollers 50 of the one-way clutch mechanism 23a rotate to a position where torque is not transferred from the common shaft 29 to the sprocket 36. Torque cannot be transferred from the sprocket 36 to the common shaft 29 until the sprocket 36 rotates faster than the common shaft 29 thereby rotating the rollers 50 to a position where torque can be transferred through them.
The output shaft 100 may be coupled directly to a shaft 128 that has the propelling member 18 directly thereon (and which may be referred to as the propelling member shaft). It will be noted that the propelling member 18 shown in FIG. 1 is oriented at an angle to a horizontal plane and as a result, some of the energy used to spin the propelling member 18 is wasted urging the watercraft 10 upwards out of the water. In another configuration, shown in FIG. 10, the output shaft 100 (not visible in FIG. 10) is coupled to an output shaft extension 130 that extends downwards at an angle to a horizontal plane. The output shaft extension 130 connects to a propelling member shaft shown at 132 by means of a U-joint 133. In another embodiment shown in FIG. 11, the drive train 14 is oriented so that the output shaft 100 (not visible in FIG. 11) extends directly vertically downwards and is coupled to an output shaft extension 134. A pair of bevel gears 136 and 138 connects the output shaft extension 134 to the propelling member shaft 140 which extends horizontally. It will be noted that in the embodiment shown in FIG. 11, the propelling member 18 is positioned proximate the front of the watercraft 10. It will be noted that, in the embodiments shown in FIGS. 1, 10 and 11, the watercraft 10 is steered by a rudder shown at 142. In yet another embodiment, shown in FIG. 12, the propelling member 18 is orientable by the rider 56 about a vertical axis 143. As a result, the rider 56 can use the propelling member 18 to direct the watercraft 10 in different directions instead of using a rudder as provided in the embodiments shown in FIGS. 1, 10 and 11. To provide this, the propelling member shaft shown at 144 in FIG. 13 engages an output shaft extension 146 through a first bevel gear 148 and a second bevel gear 150, and wherein the aforementioned components are held within an L-shaped housing 152. The housing 152 is shown as transparent in FIG. 13 to more clearly show components within the housing 152. The housing 152 has at its upper end a gear 154 that is concentric about the output shaft extension 146, and which is drivable by a steering motor 156 that has a worm 158 on its output shaft 160. When the steering motor 156 is rotated, the housing 152 rotates, which causes the second bevel gear 150 to orbit about the first bevel gear 148 until the steering motor 156 is stopped. The motor 156 may include a position encoder to provide positional feedback to the controller 118. Any suitable control device can be provided for use by the rider 56 (FIG. 12) to instruct the controller 118 to change direction of the watercraft 10. For example, two additional buttons (not shown) each representing a direction of rotation of the steering motor 156 could be provided on a control lever similar to the control lever 88 shown in FIG. 9.
It will be noted that, in some embodiments, such as the embodiments shown in FIGS. 11 and 12, the propelling member 18 is positioned proximate to the front of the watercraft 10, while in other embodiments (FIGS. 1 and 10) the propelling member 18 is positioned proximate the rear of the watercraft 10.
In use, the control lever 88 (FIG. 9) is movable between a first position and a second position which puts the watercraft 10 in a first mode or in a second mode respectively. When the control lever 88 is in the first position, the clutch 26 (FIG. 2) operatively disconnects the motor 24 from the output shaft 100 and the clutch bypass mechanisms 23a and 23b operatively connect between the manual force input members 20 and the output shaft 100 in both rotational directions. When the control lever 88 is in the second position the clutch 26 (FIG. 2) operatively connects the motor 24 to the output shaft 100 and the clutch bypass mechanisms 23a and 23b are disengaged so that the manual force input members 20 (FIG. 2) are operatively connected to the output shaft 100 through the one-way clutches 22. As a result, in situations where the motor 24 is operatively connected to the output shaft 100, the one-way clutches 22 prevent the motor 24 from back-driving the pedals 30 (FIG. 1) when the motor 24 (FIG. 4) is rotating in a direction that drives the watercraft 10 forward. It is noted that the one-way clutches 22 may permit the motor 24 to drive the sprocket 36 and the pedals 30 (FIG. 1) if the motor 24 (FIG. 4) is rotated backwards. However in the embodiment shown, the motor 24 is, as noted above, a unidirectional motor and so the situation does not arise where the motor 24 could back-drive the pedals 30 (FIG. 1).
It will be understood that, while two manual force input members 20 are included in the embodiment shown in the figures, it is alternatively possible to configure the watercraft 10 to have only one manual force input member 20. Alternatively three or more manual force input members 20 could be provided in another embodiment.
It will be noted that the torque sensor 28 may be usable advantageously in a plurality of machines between a first rotating member and a second rotating member, and is not just limited to use in watercraft.
While the above description constitutes a plurality of embodiments of the present invention, it will be appreciated that the present invention is susceptible to further modification and change without departing from the fair meaning of the accompanying claims.
Patent Application
20120238159
