Patent ID: 8790511

Claim:
A water filtering device comprising: an inner cylinder unit having an inner end opening, a closed outer end opposite to said inner end opening of said inner cylinder unit, and a first space disposed between said inner end opening and said closed end of said inner cylinder unit; an outer cylinder unit sleeved movably on said inner cylinder unit and movable relative to said inner cylinder unit to convert said water filtering device between an extended state and a retracted state, said outer cylinder unit having an inner end opening in fluid communication with said inner end opening of said inner cylinder unit, and a closed outer end opposite to said inner end opening of said outer cylinder unit; and a filter element disposed within said inner cylinder unit and adjacent to said inner end opening of said inner cylinder unit so as to define a second space between said filter element and said outer cylinder unit; wherein, when said second space is filled with water, the closed outer end of the inner cylinder is loosened slightly, and said closed outer end of said inner unit and said closed outer end of said outer cylinder unit move toward each other, the water is forced to flow from said second space into said first space through said filter element, said outer cylinder unit includes an outer cylinder formed with said inner end opening at one end thereof and a second cap with an end surface connected removably to another end of said outer unit, constituting a closed end of said outer cylinder unit, a rotary disk disposed rotatably on said second cap, a plurality of date-representing characters arranged along a circle and disposed on said end surface of said second end cap, and a pointer disposed on said rotary disk, wherein said pointer is configured as a straight slot formed in said rotary disk.