| 摘要 |
Air vent consisting of a fixed, gridlike apertured front panel and a stop plate disposed behind it, which plate is movable by a control mechanism in the direction of its plane and to the plane of the front panel and which plate in a position resting against the back of the front panel closes the grid apertures, but which in a separated position opens the grid apertures of the front panel for the passage of air.
|
