Pedal boat

A pedal boat mainly includes a hull equipped with a transmission mechanism and a steering mechanism. A tubular member is connected behind a lower rear end of the hull. The transmission mechanism includes a driving chain wheel, a gearbox, and a propeller connected to the gearbox via a shaft and located in the tubular member. The driving chain wheel can be rotated by use of two pedals connected thereto. Power generated by the rotating chain wheel is transmitted to the propeller via the gearbox at a high transmission gear ratio, so that the propeller rotates at high speed and expels water from the tubular member to move the pedal boat quickly in directions controlled by the steering mechanism. The propeller is located under water and would not splash water about to wet a user of the boat when it works. The pedal boat is manhandled by pedaling but capable of moving at high speed and is therefore an interesting water sport means.

BACKGROUND OF THE INVENTION 
The present invention relates to a pedal boat, and more particularly to a 
pedal boat that can be effortlessly operated to move at a quick speed and 
is therefore more interesting for use. 
There is a wide range of water sports, such as surfboarding, water skiing, 
water motorcycling, pedal boating, etc. While these water sports create a 
lot of funs, they are subject to some conditions. For example, the 
surfboarding would require seashore having heavy waves, the water skiing 
would require a fast motorboat to tow the water-skier, and a water 
motorcycle is expensive and tends to cause environmental pollution and is 
usually forbidden to a scenic lake. A pedal boat is manhandled and does 
not need an external force to tow it, nor will it cause any environmental 
pollution. However, the pedal boat moves slowly and is less interesting 
compared with other water sports. 
A conventional pedal boat includes a hull having two rotary wheels provided 
at two sides of the boat. The rotary wheels have a diameter larger than a 
height of the boat and include a plurality of blades. The rotary wheels 
are brought by chain wheels to rotate. A user applies force on pedals to 
rotate the chain wheels that in turn rotate the rotary wheels, and blades 
on the rotary wheels propel the boat through the water. Since the rotary 
wheels have a diameter larger than the height of the boat, the user would 
have to exert a lot of strength to drive the boat forward and the boat can 
move only at a very slow speed. Moreover, the blades always splash water 
about when they come out of the water and undesirably wet the user. As a 
result, most users are not interested in pedal boating. 
It is therefore tried by the inventor to develop an improved pedal boat to 
eliminate the drawbacks existing in the conventional pedal boat to attract 
more users. 
SUMMARY OF THE INVENTION 
A primary object of the present invention is to provide a pedal boat that 
can move at a high speed and would not splash water to wet the user. 
The pedal boat provided by the present invention includes a hull equipped 
with transmission mechanism and steering mechanism. A tubular member is 
connected behind a lower rear end of the hull. The transmission mechanism 
includes a driving chain wheel, a gearbox, and a propeller connected to 
the gearbox and located in the tubular member. The driving chain wheel can 
be rotated by use of two pedals connected thereto. Power generated by the 
rotating chain wheel is transmitted to the propeller via the gearbox at a 
high transmission gear ratio, so that the propeller rotates at high speed 
and expel water from the tubular member to move the pedal boat quickly in 
directions controlled by the steering mechanism. The propeller is located 
under water and would not splash water about to wet a user of the boat 
when it works. The pedal boat is manhandled by pedaling but capable of 
moving at high speed and is therefore an interesting water sport means 
good for training the user's body.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Please refer to FIG. 1 that shows a pedal boat according to the present 
invention. As shown, the pedal boat mainly includes a hull 10 equipped 
with a transmission mechanism 20 and a steering mechanism 30. 
The pedal boat has a backward reduced tubular member 11 connected behind a 
lower rear end of the hull 10. An area of the lower rear end of the hull 
10 facing an expanded front opening of the tubular member 11 forms an 
inward curved flow-guiding surface 12. Water flow near a bottom of the 
hull 10 is guided by the curved flow-guiding surface 12 into the tubular 
member 11. A bearing support 13 is provided on the flow-guiding surface 12 
at a predetermined position for a bearing 14 and a watertight washer 15 to 
mount thereto. 
Please refer to FIGS. 1 and 2 at the same time. The transmission mechanism 
20 mainly includes a driving chain wheel 21, a gearbox 22, and a propeller 
23 connected to the gearbox 22 and located in the tubular member 11. Two 
pedals 24 are separately connected to two sides of a center of the driving 
chain wheel 21. Inside the gearbox 22, there are a driven chain wheel 221 
cooperating with the driving chain wheel 21 and having teeth less than 
that of the driving chain wheel 21, a first gear 222 coaxial with the 
driven chain wheel 221 and having teeth more than that of the driven chain 
wheel 221, a second gear 223 meshing with the first gear 222 and having 
teeth less than that of the first gear 222, a third gear 224 coaxial with 
the second gear 223 and having teeth more than that of the second gear 
223, a fourth gear 225 meshing with the third gear 224 and having teeth 
less than that of the third gear 224, a first bevel gear 226 coaxial with 
the fourth gear 225, and a second bevel gear 227 meshing with the first 
bevel gear 226. The second bevel gear 227 is supported on one end of a 
shaft 228 that extends through the bearing support 13 to connect to the 
propeller 23. When the driving chain wheel 21 is caused to rotate by use 
of the pedals 24, it generates a power that is transmitted to the 
propeller 23 via the driven chain wheel 221 and the first, the second, the 
third, and the fourth gears 222, 223, 224, 225 and the first and the 
second bevel gears 226, 227 in the gearbox 22. Since the gearbox 22 
provides a high transmission gear ratio, the power transmitted from the 
driving chain wheel 21 to the propeller 23 causes the propeller 23 to 
rotate at a high speed. 
Please refer to FIGS. 1, 3, 4 and 5 at the same time. The steering 
mechanism 30 mainly includes a flexible tube 31 connected to a reduced 
rear end of the tubular member 11. A cord 32 is wound about a rotating 
disc 34 located at a front part of the boat with its two free ends 
separately passing a group of pulleys and being finally connected to two 
sides of the flexible tube 31. A steering device 35 is connected to the 
rotating disc 34 to upward project therefrom. By manipulating the steering 
device 35, the rotating disc 34 is controlled to rotate in different 
directions and thereby pulls the cord 32 leftward or rightward. The cord 
32 being pulled in different directions in turn causes a rear end of the 
flexible tube 31 to swing toward different directions and at different 
angles of inclination. 
Please refer back to FIG. 1. To operate the pedal boat of the present 
invention, a user may take a seat in the hull 10 and work on the pedals 24 
with feet, so that the driving chain wheel 21 is brought by the pedals 24 
to rotate. With the high transmission gear ratio provided by the gearbox 
22, the power generated by the rotating driving chain wheel 21 is able to 
cause the propeller 23 to rotate at a high speed and constantly expels 
water from the tubular member 11 via the flexible tube 31 connected to the 
rear end of the tubular member 11. The water expelled from the rear end of 
the tubular member 11 and the flexible tube 31 generates a push force that 
pushes the pedal boat forward. Since the tubular member 11 is gradually 
reduced from its front to the rear end, water in the tubular member 11 is 
compressed before being expelled from the tubular member 11. That is, the 
propeller 23 works in the rearward reduced tubular member 11 in a manner 
similar to a turbine wheel. Meanwhile, since the flexible tube 31 of the 
steering mechanism 30 is connected to the rear end of the tubular member 
11 and the water in the tubular member 11 would be expelled via the 
flexible tube 31, the swing direction of the flexible tube 31 caused by 
turning the steering device 35 can determine the direction in which the 
pedal boat moves. 
To enable the propeller 23 to keep rotating after the user has stopped 
pedaling the pedal boat, a one-way ratchet wheel may be mounted on one of 
the gears in the gearbox 22 and flywheels 229 may be coaxially connected 
to the gear having the one-way ratchet wheel to keep the propeller 23 
rotate under rotational inertia. 
An air duct 16 may be extended at a lower end into a front portion of the 
tubular member 11 with an upper end thereof projected from a top of the 
hull 10, so that air may be guided into the tubular member 11 via the air 
duct 16 to enhance water compression in the tubular member 11. 
The present invention employs simple structure to largely increase the 
moving speed of the pedal boat and therefore makes the pedal boat more 
interesting for use. Meanwhile, the propeller 23, the tubular member 11, 
and the flexible tube 31 for propelling the pedal boat through the water 
all are located under the water and would not splash water about when they 
work to propel the pedal boat. Since the pedal boat of the present 
invention is driven by physical strength, it also provides a very good 
means for users to train themselves for good physical condition. 
Since designs of the pedal boat about its braking and waterproof ability 
and the structural design of the flywheel are prior arts, they are not 
repeated herein.