Battery pack provided with outer casing

1. A battery pack to be connected to electronic equipment, the battery pack comprising:

a plastic-made, elongated outer casing having peripheral walls interconnected to define a battery storage portion, the outer casing comprising a mounting protrusion to be attached to a casing of the electronic equipment and project therefrom in the attached state;

an inner casing incorporated inside the battery storage portion of the outer casing at the mounting protrusion; and

at least one battery accommodated in the battery storage portion inside the outer casing,

wherein the mounting protrusion is a double structure comprised of the outer casing and the inner casing, and the battery is accommodated inside the double structure, and the battery accommodated inside the double structure is located outside the electronic equipment when the mounting protrusion is in the attached state,

wherein the inner casing has an anti-shock rib formed integrally at an end of the inner casing,

wherein the inner casing has an integrally formed side wall disposed inside the outer casing, and the anti-shock rib is connected to the side wall, and

wherein the inner casing has a plurality of the anti-shock ribs, and the outermost one of the anti-shock ribs is made thicker relative to an innermost one of the anti-shock ribs which is closest to the battery.

2. The battery pack as recited in claim 1 , wherein the inner casing has anti-shock ribs formed integrally at opposite ends of the inner casing.

3. The battery pack as recited in claim 1 , wherein at least one of the anti-shock ribs of the inner casing is connected to the outer casing.

4. The battery pack as recited in claim 1 , wherein the inner casing has an integrally formed separation wall that opposes a terminal electrode of the battery, and at least one of the anti-shock ribs is disposed between the separation wall and the side wall.

5. The battery pack as recited in claim 1 , wherein the outer casing has a slanted surface at a corner of the mounting protrusion, the side wall of the inner casing being located interiorly of the slanted surface, and the plurality of anti-shock ribs are formed integrally with the inner casing so as to extend inwardly from the side wall.

6. The battery pack as recited in claim 1 , wherein a connection rib is formed integrally between two of the anti-shock ribs.

7. The battery pack as recited in claim 1 , wherein the plurality of anti-shock ribs are disposed near an end face of the battery.

8. The battery pack as recited in claim 7 , wherein the inner casing further has a planar rib and a plurality of connection ribs at a portion where the plurality of anti-shock ribs are connected with the outer casing, the planar rib being connected in a direction orthogonal to the anti-shock ribs and the plurality of connection ribs being disposed with respect to the outer casing in a connection orthogonal to the planar rib; and the planar rib and the connection ribs are formed integrally with the inner casing.

9. The battery pack as recited in claim 7 , wherein the inner casing has, inside the mounting protrusion, the plurality of anti-shock ribs near the battery, and further has the plurality of anti-shock ribs connected to the outer casing.

10. The battery pack as recited in claim 7 , wherein the outer casing has a lateral protrusion, and the plurality of anti-shock ribs are provided at an end of the lateral protrusion.

11. The battery pack as recited in claim 10 , wherein the inner casing has an integrally formed planar rib that opposes an inner side of the peripheral walls at the lateral protrusion of the outer casing, and the plurality of anti-shock ribs are connected to the planar rib.

12. The battery pack as recited in claim 11 , wherein a slanted rib is integrally formed at a corner between the planar rib and one of the anti-shock ribs to connect the planar rib and the one anti-shock rib together in a triangular form.

13. The battery pack as recited in claim 1 , wherein the battery is a cylindrical battery.

14. The battery pack as recited in claim 1 , wherein the battery is a lithium-ion battery.

15. The battery pack as recited in claim 1 , wherein the battery has a plurality of cells linearly interconnected in series to make up a battery module.

16. The battery pack as recited in claim 1 , wherein the inner casing is interposed between a bottom surface of the outer casing and the battery.

17. A battery pack to be connected to electronic equipment, the battery pack comprising:

a plastic-made, elongated outer casing having peripheral walls interconnected to define a battery storage portion, the outer casing comprising a mounting protrusion to be attached to a casing of the electronic equipment and project therefrom in the attached state;

an inner casing incorporated inside the battery storage portion of the outer casing at the mounting protrusion; and

a battery comprising a plurality of battery modules accommodated in the battery storage portion inside the outer casing, the battery modules being disposed in a parallel arrangement,

wherein the mounting protrusion is a double structure comprised of the outer casing and the inner casing, and an outermost one of the battery modules is accommodated inside the double structure, and the outermost battery module, which is accommodated inside the double structure, is located outside the electronic equipment when the mounting protrusion is in the attached state,

wherein the inner casing has an anti-shock rib formed integrally at an end of the inner casing,

wherein the inner casing has an integrally formed side wall disposed inside the outer casing, and the anti-shock rib is connected to the side wall, and

wherein the inner casing has a plurality of the anti-shock ribs, and the outermost one of the anti-shock ribs is made thicker relative to an innermost one of the anti-shock ribs which is closest to the battery.