| 摘要 |
A window structure comprising a rectangular window frame, a rectangular sash frame within the window frame and supporting a glass pane, pivotal mounting means at and between the tops and bottoms of the frames on the central vertical axes thereof and comprising pivot pin plates mounted on the sash frame and having vertical pivot pins projecting therefrom and receiver fixtures mounted on the window frame and having bearing openings rotatably receiving the pivot pins, one of said mounting means including stop means to stop pivotal opening of the sash frame when that frame is pivoted to a predetermined partially opened position and comprising a key plate shiftably carried by the receiver fixture and normally occurring radially outward of the pin, spring means urging the key plate toward the pin, a keyway in the pin and shiftable into alignment with the key plate when the frames are moved to said partially open position, whereupon the plate shifts into stopping relationship in the keyway and manually operable operating means to yieldingly urge the key plate out of the keyway. |
