Patent ID: 8455125

Claim:
A fixing mechanism, comprising: a battery sleeve defining an open end to receive a battery, the battery sleeve comprising a latching protrusion formed in an inner surface thereof adjacent to the open end; a resilient member fixed to the inner surface of the battery sleeve; and a battery cover comprising a body portion and a cover portion formed at an end of the body portion, the body portion being substantially cylindrical shaped and comprising: an outer side surface, the outer side surface comprising a curved portion and a flat planar portion connected with the curved portion, a guide groove defined in the curved portion of the outer side surface, the guide groove comprising a first end defined at an intersection of the curved portion and the flat planar portion and a second end opposite to the first end, and a latching groove defined in the curved portion of the outer side surface and connecting with the second end of the guide groove; wherein the battery cover is rotatably engaged with the battery sleeve via the open end, the latching protrusion slides from the flat planar portion to the guide groove until the latching protrusion is locked in the latching groove, and the resilient member presses the battery to resist the battery cover.