Panic Exit Hardware Cylinders with Free-Return Return Springs
Engineering Overview: Engineering analysis of Euro profile cylinders equipped with internal return springs that automatically return the drive cam to vertical rest for panic push bars.
Technical & Engineering Specifications
| Standard | EN 1125 Panic Exit Hardware / EN 179 Emergency Exit |
|---|---|
| Mechanism | Internal Torsion Spring-Return Drive Cam |
| Application | Public Venues, Stadiums, Shopping Centers |
| Operating Force | < 15 N Push Bar Release Force |
Emergency Exit Bar Coordination
On emergency escape doors with horizontal push bars (EN 1125), leaving a cylinder cam partially turned can deadlock the push bar linkage.
Spring-Return Cam Kinematics
- Internal Torsion Spring: An internal spring automatically returns the drive cam to its neutral resting angle immediately after key rotation.
- Zero Latch Drag: Guarantees the emergency crash bar can retract the latchbolt with $<15\text{ N}$ push force at all times.
Frequently Asked Engineering & Selection Questions
Q1: How does a spring-return cam protect panic exit doors?
It automatically snaps the lock cam back to neutral after key use, ensuring the panic push bar never jams during emergency evacuation.