1. Field of the Invention
The present invention relates to a file folder, and more particularly to a file folder having a structure for preventing a clip from being disengaged from the file folder inadvertently.
2. Description of the Prior Art
Typical file folders comprise a front sheet, a back sheet, a folder strip formed between the front sheet and the back sheet and foldable relative to the front sheet and the back sheet, to receive paper sheets between the front sheet and the back sheet. A clip is further provided and engaged onto the edge portions of the front sheet and the back sheet, to clamp and retain the paper sheets between the front sheet and the back sheet.
For example, U.S. Pat. No. 4,904,104 to Gloeckle discloses one of the typical file folders which also comprises a clip provided to clamp and retain the paper sheets between the front sheet and the back sheet. However, a long slit or cut is required to be formed in the folder strip to receive the clip, and the clip may not be easily engaged through or into the slit or cut of the folder strip. In addition, the folder strip may interfere with the operation of the clip.
The applicant has also developed a file folder which is disclosed in U.S. Pat. No. 5,226,676 to Su, and which comprises three foldable strips coupled to a base sheet. One of the strips that is located close to the base sheet includes an opening formed therein to receive the clip. However, the foldable strips may be easily curled and may not be retained in position. In addition, the foldable strips may also interfere with the operation of the retaining clip.
U.S. Pat. No. 5,285,952 to Ho discloses another typical file folder which comprises two slits perpendicular to the slit or cut as shown in Gloeckle, to slidably receive two protrusions extended from the clip, and which comprises two holes formed in the ends of each of the slits, to receive the protrusions of the clip.
However, when the clip is slid away from the file folder or when the clip is completely engaged onto the file folder, the protrusions of the clip will be aligned with the holes of the file folder, and will be easily disengaged from the file folder.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional file folders.