摘要 |
The invention is related to a reservoir tank receiving liquid therein and having a peep hole in a side wall for visually inspecting the interior of the tank. The peep hole is formed by a cup-shaped member having a transparent bottom wall, a cylindrical side wall sealingly fitted into an opening formed in the side wall of the reservoir tank, and a plurality of retaining portions formed adjacent the open end portion of the cup-shaped member for engagement with the peripheral edge of the opening.
|