| 摘要 |
An upper fastener device and a lower fastener device (11, 12) are used to secure a first door section (2-4, 7) to the door frame, the upper device being secured to a position in the upper half of the frame and the lower device being secured to a position in the lower half of the frame. At least one hinge (8) connects the first door section to a second door section (3, 7) so that the door can be unfolded from a state with a narrow width to a state with a wide width. |
