Leg protection device

1. A leg protection device for protecting a leg of an occupant in a vehicle, comprising:

a casing,

an airbag disposed in the casing in a folded state to be inflated in front of the leg of the occupant, said airbag having a front portion facing the occupant and a rear portion opposite to the front portion in an inflated state, and

gas generating device attached to the airbag for inflating the airbag,

wherein said airbag comprises an upper folded portion folded between the front portion and the rear portion at an upper side of the airbag in a spread state of the airbag, left and right side portions folded over a center area of the airbag with the upper folded portion such that parts of the left and right side portions to be folded later are located laterally outside the casing in a partly folded state of the airbag, and an intermediate folded portion, in another partly folded state of the airbag, having a width to be able to enter into the casing in a direction perpendicular to the left and right side portions, said intermediate folded portion being obtained by folding rearwardly a part of the airbag with the upper folded portion and the left and right side portions several times, said parts of the left and right side portions located laterally outside the casing being folded on a center area to be completely disposed inside the casing in the folded state, and

wherein said upper folded portion includes a pleated portion in which a perimeter of the airbag is folded at least once inwardly between the front portion and the rear portion.

2. A leg protection device according to claim 1 , wherein each of said left and right side portions has a folded portion folded between the front portion and the rear portion in the spread state of the airbag.

3. A leg protection device according to claim 1 , wherein said airbag further includes a lower folded portion formed at a lower side of the airbag.

4. A leg protection device according to claim 1 , wherein said airbag includes a rolled portion rolled along a horizontal direction relative to the occupant in the folded state, said rolled portion having folded left and right sides.

5. A leg protection device according to claim 4 , wherein said folded left and right sides are folded with pleats or rolled.

6. A leg protection device according to claim 4 , wherein said airbag is arranged such that the upper folded portion expands outwardly between the front and rear portions after the rolled portion is unrolled.

7. A leg protection device for protecting a leg of an occupant in a vehicle, comprising:

a casing,

an airbag disposed in the casing in a folded state to be inflated in front of the leg of the occupant, said airbag having a front portion facing the occupant and a rear portion opposite to the front portion in an inflated state, and

gas generating device attached to the airbag for inflating the airbag,

wherein said airbag comprises an upper folded portion folded between the front portion and the rear portion at an upper side of the airbag in a spread state of the airbag, left and right side portions folded over a center area of the airbag with the upper folded portion such that parts of the left and right side portions to be folded later are located laterally outside the casing in a partly folded state of the airbag, and an intermediate folded portion, in another partly folded state of the airbag, having a width to be able to enter into the casing in a direction perpendicular to the left and right side portions, said intermediate folded portion being obtained by folding rearwardly a part of the airbag with the upper folded portion and the left and right side portions several times, said parts of the left and right side portions located laterally outside the casing being folded on a center area to be completely disposed inside the casing in the folded state, and

wherein said airbag includes an upper portion rolled along a horizontal direction relative to the occupant and a lower portion folded over the upper portion in the folded state, said rolled upper portion having folded left and right sides disposed above the folded lower portion.

8. A leg protection device according to claim 7 , wherein said folded left and right sides are folded with pleats or rolled.

9. A leg protection device for protecting a leg of an occupant in a vehicle, comprising:

a casing,

an airbag disposed in the casing in a folded state to be inflated in front of the leg of the occupant, said airbag having a front portion facing the occupant and a rear portion opposite to the front portion in an inflated state, and

gas generating device attached to the airbag for inflating the airbag,

wherein said airbag comprises an upper folded portion folded between the front portion and the rear portion at an upper side of the airbag in a spread state of the airbag, left and right side portions folded over a center area of the airbag with the upper folded portion such that parts of the left and right side portions to be folded later are located laterally outside the casing in a partly folded state of the airbag, and an intermediate folded portion, in another partly folded state of the airbag, having a width to be able to enter into the casing in a direction perpendicular to the left and right side portions, said intermediate folded portion being obtained by folding rearwardly a part of the airbag with the upper folded portion and the left and right side portions several times, said parts of the left and right side portions located laterally outside the casing being folded on a center area to be completely disposed inside the casing in the folded state,

wherein said parts of the left and right side portions in the intermediate folded portion are folded at least once to be located in the casing, and

wherein said airbag includes a lower portion located below the casing in the spread state, said lower portion having a portion folded between the front portion and the rear portion and being located above the intermediate folded portion when the intermediate folded portion is formed and disposed in the casing.

10. A leg protection device according to claim 9 , wherein said parts of the left and right side portions are folded once to be located inside the casing.