Free-Wheeling Cams in Emergency Panic Exit Crash Bars (EN 1125 Standards)
Engineering Overview: Engineering guide on free-wheeling (freerun) cylinder cams for panic exit crash bars, ensuring instantaneous egress during emergency evacuations.
Technical & Engineering Specifications
| Cam Type | Free-Wheeling / Freerun 360° Panic Cam |
|---|---|
| Function | Cam spins freely to prevent blocking emergency exit bars |
| Standard | EN 1125 / EN 179 Panic Hardware Standards |
| Application | Auditoriums, School Exits, Cinema Panic Doors |
Emergency Panic Egress Kinematics
On emergency fire exit doors equipped with horizontal panic push bars (EN 1125), a standard fixed cam can block the internal latch retraction if left partially turned.
Free-Wheeling (Freerun) Cam Mechanism
- 360° Free Rotation: When the key is removed, the cam disengages from the core plug and spins freely.
- Instant Egress: Depressing the panic push bar rotates the internal lock mechanism without meeting any mechanical resistance from the cylinder cam.
Frequently Asked Engineering & Selection Questions
Q1: Why are free-wheeling cams used with panic exit bars?
The cam spins freely when the key is out, ensuring that pushing the emergency panic bar instantly opens the door without catching on the lock cam.