Importance

Loading Importance Indicators...

Abstract

A push door opening mechanism for use where protection from fire is sought. In operation the push handle causes a spring biased operating lever to rotate within the door opener. The operating lever pulls a bolt which allows the door to open. When the lever is in the return position, a cavity in the operating lever is positioned adjacent to a locking pin. That pin is held in the base plate and is longer than the depth of the cavity in the operating lever. The locking pin is also mechanically biased to move into the cavity. Once positioned in the cavity, the rotation of the operating lever is jammed because the locking pin is partially in the operating lever and partially held rigid in the base plate. However, during normal operation, the locking pin is retained out of the cavity by a low melting point fusible link pin. During a fire the base plate becomes hot, causing the link pin to melt which frees the locking pin. The locking pin then moves into the cavity in the operating lever and jams the push door opener.

Loading the Abstract Image...

First Claim