EMERGENCY EXIT DOOR LATCH

摘要

EMERGENCY EXIT DOOR LATCH WITH HYDRAULIC RETARDATION OF BOLT RETRACTION of the Invention An emergency exit door latch includes a pivoted bolt which pivots into registration with a keeper and is urged in the projected position by a spring biased plunger. The spring biased plunger is retained within a hydraulic cylinder. Hydraulic lines connect the portion of the hydraulic cylinder in front of the plunger to the portion behind the plunger through a throttling means. Upon pressing against the door, the swinging urges the plunger rearwardly so as to force fluid in the rear portion of the hydraulic cylinder through the line and the throttling means to the front portion of the hydraulic cylinder thereby allowing the bolt to slowly retract as the fluid is throttled. Preferably, a push bar is provided having a detent means thereon which locks the bolt in it projected position. Upon pressing the push bar, the bolt is released so that it can be slowly retracted as pressure is placed on the door. Preferably, there is an emergency release system which allows rapid transfer of fluid from the rear of the piston to the front of the piston upon the occurrence of an emergency condition such as tripping of a fire alarm or smoke alarm. This emergency system allows the hydraulic fluid to bypass the throttling device which generally retards retraction of the bolt. An alarm system is connected to the latch and sounds whenever the latch is operated so as to alert personnel within the building that someone is trying to open the emergency door without authorization.