A latching system for a double-hung window including upper latches and anti-bow latches where the upper latches and the anti-bow latches are operated by a common activating mechanism for ease of use of the window. A single activating mechanism may be utilized for latches on both sides of a window, or...http://www.google.es/patents/US7412800?utm_source=gb-gplus-sharePatente US7412800 - Latching and anti-bow mechanism for a window
