Patent ID: 7420799

Claim:
A case structure of a portable electronic device comprising: a first shell; a first engagement element protruding from the first shell; a second shell having a first penetrating opening and a second penetrating opening located on different sidewalls of the second shell respectively, wherein the first penetrating opening is perpendicular to the second penetrating opening, and the first penetrating opening allows the first engagement element to pass through the second shell; a second engagement element set in the second shell having a button portion and an embedding portion, wherein the embedding portion is used for engaging with the first engagement element, and the button portion movably set in the second penetrating opening for driving the embedding portion to move along a direction perpendicular to the axis of the first penetrating opening; a first spring element located in the second shell used to push the second engagement element back to its native position along the inverse direction, wherein one end of the first spring element contacts a first sidewall of the second shell, and the opposite end contacts the second engagement element; a plug element set in the second shell having a plug portion aligning with the first penetrating opening; and a second spring element located in the second shell used to push the plug element for driving the plug portion, one end of the second spring element contacting the sidewall of the second shell, and the opposite end contacting the plug element, wherein the button portion of the second engagement element is pushed to drive the embedding portion to release the first engagement element, the plug portion is driven by the second spring element to make the plug portion fill into the first penetrating opening and push the first engagement away from the first penetrating opening.