Safety Catcher Vs. Rod Lock – What Do I Need?

Safety catchers and rod locks are very similar, but they have different functions. Safety catchers are meant to do just that, catch a falling or sinking load. Implementing a safety catcher on a separate guide rod is vital to preventing catastrophic damage from a falling platen.

A rod lock system is designed to position and hold along a rod. So, it’s less about safety and more about the refined position, although rod locks can be added to a safety system in conjunction with a safety catcher for redundancy and simplify system recovery.

But, what is the real difference between a safety catcher and a rod lock, and how do I select the best option for my specific application? 

AMLOK position hold, power-off rod locking device is a double-acting solution with springs that create the holding capacity as seen below (RLN and RCH). It holds the load during a power or pressure loss and is designed to directly attach to your cylinder/actuator providing holding in both directions. It can also be used in stand-alone applications.

A safety catcher is a single-acting, self-intensifying solution that functions similar to a finger trap where the load creates the holding—so more load equals higher holding forces.  

So, which one is the correct device for you?

Ask yourself, “Is my application a ‘position and hold’ or ‘gravity fall’ application?

Answer: Position and Hold Application
Solution: AMLOK series
Why: Amlok units are bi-directional precision locking devices that hold in a precise location. The best solution for holding your rod or cylinder in place mechanically is the AMLOK. Whether you need to hold an external load in place or counteract the inherent issues with a cylinder (over travel, bouncing, drifting, reverse travel) this is the best way to resolve these issues. If positioning is important to your team, then Amlok is the solution.

Answer: Gravity Fall
Solution: Sitema Safety Catcher
Why: In the case of a falling load where you want a safe and reliable solution, a SITEMA Safety Catcher is the Defacto standard. These are designed to decelerate and stop a falling load in the event of a gravity fall situation. The device is single-acting. This creates a situation where the load is held until the power system is back online and functioning (you need to move the press upwards after power is restored to “reset” the SITEMA ensuring you are in a safe condition. 

How do I choose the correct device?

Answer: 

• If the application is a “position and hold” application, then utilize the AMLOK series units. 

• If the applications is a “gravity fall” condition, then utilize the SITEMA Safety Catcher. 

• For special custom applications, please consult with an engineer at AME. 

The simple way to look at what you need: 

• Position and hold: AMLOK
• Bi-Directional Movement: AMLOK
• On the end of a cylinder:  AMLOK

• Press Safety: Typically SITEMA

• Safety Solution for Press Applications: Typically SITEMA
• Gravity Fall Prevention: SITEMA
• Braking Applications: SITEMA

At the end of the day, there can be some overlap on the different clamping solutions. Please consult the factory for any advice on your application. 

Add a new comment :