| 摘要 |
PROBLEM TO BE SOLVED: To use a filter for a long period of time by a method wherein a filter element is foldable and has two hooks on each side and the unused part of the filter element that is folded and stored is pulled out and stretched straight to make it ready to use. SOLUTION: A sheet of a filter element 1 can be folded into several layers and the half of it is stretched straight to make it ready to use. The rest half is kept folded and set in a holding frame 2. Cuts are made at specified positions on the holding frame 2 to form filter element fasteners 6 that are bent inward. The filter element 1 that is folded and stored is fastened by the fasteners 6. Two hooks 8 provided on each side of the filter element 1 is fitted in holes 7 formed in the holding frame 2 to hold the filter element 1. When the stretched part of the filter element 1 gets dirty, the unused part of the filter element 1 that is folded and stored is pulled out and stretched straight to make it ready to use. |
