Patent ID: 8381447

Claim:
A door panel opening and closing device for a casing, comprising: a face panel including a base wall and a first post disposed on said base wall; a door panel including a pivot arm connected pivotally to said base wall, a pivot juncture between said pivot arm and said base wall being defined as a turning axis, said pivot arm including a second post disposed parallel to and spaced apart from said first post, said door panel being turnable about the turning axis between a closed position where said door panel shields a front side of said face panel and an open position where said front side of said face panel is accessible, wherein said face panel further includes a sidewall connected to said base wall, said door panel further including a panel body for shielding said front side of said face panel, said pivot arm being disposed on a rear surface of said panel body, and including a stop portion for abutting against an inner wall surface of said sidewall so as to limit a turning angle of said panel body; and a resilient member having two ends connected respectively to said first post and said second post i when said door panel is disposed at the closed position, said second post and the turning axis are located at an inner side of said first post, the turning axis is located at a front side of said resilient member, and said first and second posts and the turning axis cooperatively define a triangle i when said door panel is disposed at a specific angular position between the closed position and the open position, said first post, the turning axis, and said second post are sequentially located on a same straight line; said door panel automatically springing to the open position by virtue of a change in a direction of a force component of a tension force of said resilient member to an outward direction once said door panel is turned from the closed position past the specific angular position.