Background of the Invention Conventional amphibious caterpillar vehicle uses a driving wheel (for example sprocket) and a driven wheel (for example sprocket) which can rotate at the frontal and rear sides of the main body respectively, and a caterpillar in which a plurality of track shoes are interconnected like chain is rolled on the outside of the driving wheel and driven wheel.

In this conventional amphibious caterpillar vehicle, the caterpillar, which is rolled like chain at the driving wheel and driven wheel, is rotated according to the rotation of the driving wheel. At this time, the rotating caterpillars which contact the ground pushes forward the amphibious caterpillar vehicle that it moves in the rotating direction of the caterpillar.

Tanks or construction heavy equipments which move on the ground are examples of the conventional amphibious caterpillar vehicle. In these vehicles, the track shoe of the caterpillar is made of metal or metal combined with rubber.

Also the amphibious caterpillar vehicle with mobility on land and water such as armored car, as show in Fig. 7, employs a track shoe wherein a connecting bracket 7 is formed on the frontal and rear side so that adjacent track-shoes 5 can be interconnected by using pin, and wherein a plurality of square shaped ribs 1 tare formed on the outside of the track-shoe body 6 in the protruding form interconnecting each other.

In this type of track-shoe, the rib 11 on the center portion of in said ribs 11 has a groove 12 with predetermined depth between the inside surface of the rib 11 and outside surface of the track-shoe body 6. In this groove 12, rubber materials 13 are inserted to prevent damage of road and to absorb vibration. In addition, a sprocket catching hole 14 is formed on the track-shoe body in the same place of the rib between the rib 11 on the center and a rib on the edge, and with the same shape as

the shape of the interior portion. After the track-shoes are interconnected forming a caterpillar, driving wheel is inserted in the sprocket catching hole 14 to rotate the caterpillar of the vehicle.

The function of track-shoe 5 installed on the conventional amphibious caterpillar vehicle with mobility on land and water which is the same as the track-shoe installed on the tank and construction heavy equipments in that the track-shoe pushes forward the vehicle by the rotation of caterpillar. However, the track shoe of amphibious caterpillar vehicle has additional function of pushing out water by the ribs 11 and grooves 12 formed by the ribs 11.

By the way, the amphibious caterpillar vehicle with mobility on land and water is in the form of ship to confer buoyancy to the vehicle. However, since metallic track-shoe 5 is used in conventional amphibious caterpillar vehicle, the caterpillar which is made by interconnecting the track-shoes like chain is very heavy, and too much power is required to propel the vehicle in the water.

Further, this problem restricts the development of amphibious caterpillar vehicle for leisure employing caterpillar for amphibious vehicle such as an armored vehicle, so conventional caterpillar vehicles for leisure is used only on ground or on the water.

Disclosure of the Invention The object of the present invention is to provide a track-shoe for the caterpillar of amphibious caterpillar vehicle mobility on land and water, which helps the vehicle float on the water and reduces the required power for propelling the vehicle, by forming the track-shoe with structure that can makes the track-shoe easily float and by forming an arc-shaped groove in order to push out the water.

To accomplish this object, the present invention provides a track-shoe of a caterpillar of an amphibious caterpillar vehicle, the caterpillar being installed between a driving wheel and a driven wheel which can rotate on both sides of the vehicle, and the track-shoe including: a connection bracket formed protruding on the front and rear sides of the track-shoe body to interconnect adjacent track-shoes ; an hill-shaped protrusion formed below the track-shoe body; an arc-shaped groove formed on the front side of the track-shoe body the hollow surface being in the direction of rotation of the caterpillar; and a hollow space formed inside the track-shoe body.

Also the present invention provides a track-shoe wherein the hollow space formed inside the track-shoe body is filled with buoyant material with low specific weight.

Brief description of the Drawings Fig. 1 is a schematic plane view of an amphibious caterpillar vehicle installed according to the present invention; Fig. 2 is a side view of track-shoe of Fig. 1; Fig. 3 is a sectional view illustrating the connection of the driving wheel and the body of the amphibious caterpillar vehicle; Fig. 4 is a sectional view cut through A-A line in Fig. 1 illustrating the winding of the caterpillar to the driving wheel; Fig. 5 is a bottom prospective view of the track-shoe according to the present invention; Fig. 6 is a partial sectional view of enlarged"B"part in the Fig. 4; and Fig. 7 is a prospective view of the track-shoe of the conventional amphibious armored car with mobility on land and water.

Best Mode for Carrying out the Invention The a track-shoe of the amphibious caterpillar vehicle according to the present invention will be described in detail with reference to the preferable embodiment along with the attached drawings.

The track-shoe of this embodiment is, as shown in Fig. 1 and 2, a part constructing a caterpillar 3 which is made of track-shoes 5 interconnected like a chain, and which is installed between a driving wheel 1 and a driven wheel 2 which can rotate on both sides of the vehicle 4.

A connecting bracket 7is formed protruding on the front and rear side of the track-shoe body 6 for interconnecting adjacent track-shoes 5 by using a pin 5a, and the hill-shaped protrusion 8 is formed below the track-shoe body 6. The hill-shaped protrusion 8 is preferably built in a body with the track-shoe body 6.

An arc-shaped groove 9 is formed on the front side of the track-shoe body 6, i. e. the surface seen from the direction of rotation of the caterpillar 3. This arc-shaped groove 9 has the function of pushing out water so that the vehicle can be propelled when the caterpillar 3 rotates. The arc- shaped groove 9 is preferably built in a body with the track-shoe body 6. Also, hollow space is formed inside the arc-shaped groove 9 and the track-shoe body 6, reducing the weight of the caterpillar and enabling the vehicle easily float on the water.

In another embodiment, as shown in Fig. 6, the hollow space formed inside the track-shoe body 6 is filled with buoyant material 15 having low specific weight such as foamed polystyrene or foamed urethane to increase buoyancy.

As mentioned above, the track-shoes form the caterpillar 3 by interconnecting adjacent track- shoes through connection brackets 7 by using pin Sa, and the caterpillar 3 is installed rolling on the driving wheel 1 and driven wheel 2 of the amphibious caterpillar vehicle as shown in Figs. 4 and 6.

The driving wheel 1 and driven wheel 2 may have the structure that can rotate the caterpillar 3, and in the embodiment of the present invention, as shown in Fig. 3, a cylindrical pipe 17 is installed in the center between two circular boards 16 providing buoyancy to the driving wheel 1 and driven wheel 2. Also, a plurality of rollers 18 are installed with predetermined interval on the outer surfaces of two circular boards 16 outside the cylindrical pipe 17 so that hill-shaped protrusion 8 formed below the track-shoe body 6 can be hooked making it possible to rotate the caterpillar by using the roller 18 and hill-shaped protrusion 8.

The driving wheel 1 and driven wheel 2 are connected to rotating axis 19 respectively, and a driven gear 20 is installed on one of the rotating axes 19 and the driven gear 20 is connected to driving gear part 22 through chain 21 which are built on the body 4 of the amphibious caterpillar vehicle.

The driving gear 22 is constructed so that driving power is transferred to the driven gear 20 by using motor or by using a passenger pedal a hand-operated pedal of bicycle-type.

The part 24 which has not yet described is a support of the caterpillar 3 which is formed protruding outside the both sides of the body 4 of the amphibious caterpillar vehicle. A supporting roller 25 which prevents the caterpillar 3 from slacking is formed on the caterpillar by a supporting bracket 24.

Now the installation of the caterpillar using the track-shoe of the present invention and the operation of the amphibious caterpillar vehicle using the caterpillar will be described with reference to Figs. 1 and 6.

The caterpillar 3, as shown in Fig. 4 and 6, are constructed by interconnecting the track-shoes in the form of a chain by overlapping connection brackets formed at the front and rear side of the body 5 by inserting a pin 5a.

The caterpillar 3 is installed rolling the driving wheel 1 and driven wheel 2 of the amphibious caterpillar vehicle. In this step, the hill-shaped protrusion 8 formed below the track-shoe body 6 is placed contacting the driving wheel 1 and driven wheel 2 (See Figs. 4 and 6), and each hill-shaped protrusion 8 is placed between the rollers 18 which are formed with predetermined interval on the driving wheel 1 and driven wheel 2 respectively.

In this state, as shown in Fig. 3, by operating the driving gear part 22, driving power of the driving gear is transferred to the driven gear 21 through the chain 21 and the transferred driving power of the driven gear 20 rotates the driving wheel 1 formed on both sides of the upper ends of the rotating axis.

Since the hill-shaped protrusion 8 of track shoe body 6 is hooked on the rollers 18 installed on the driving wheel 1 and driven wheel 2, the driven wheel 2 and the caterpillar 3 can rotate by the rotation of the driving wheel, propelling the amphibious vehicle 10.

And, the arc-shaped groove on the front side of the track shoe body composing the caterpillar pushes out water when the caterpillar rotates in the water and propels the amphibious caterpillar vehicle.

Although the material and shape of the body of the amphibious caterpillar vehicle are not described in this embodiment, any material that can make the body of the amphibious caterpillar vehicle float on the water may be used in the embodiment, and the shape of the body is preferably the shape that can maintain stable state while having less propelling resistance such as the shape of a ship.

The amphibious-caterpillar vehicle 10 using the track-shoe of the present invention, as described above, is propelled by the hill-shaped groove in the water, and on the ground such as sand, it is propelled by the track shoe contacting the ground.

Industrial Applicability According to the present invention, by installing the caterpillar composed of track-shoes having a hollow space inside, the vehicle can float with ease and also can be propelled by the arc-shaped groove at the front side of the track-shoe.

In addition, when the track-shoe is applied to the amphibious caterpillar vehicle for leisure with mobility on land and water, the use of the amphibious caterpillar vehicle can extended and can give much interests to the passenger.