This is what distinguishes the safety catcher:
  • Safety of people and machine
  • Clamping force without energy supply
  • For vertical use
  • Pneumatic or hydraulic
  • Holding load through self-reinforcement principle
  • DGUV-Test certified

Use and application of the safety catcher
The safety solution for people and machine

The safety catcher is based on our experience with clamping units of the Ratio Clamp® design, which has grown since 1965. We have specifically developed this proven technology to ensure maximum safety in applications on vertical, gravity-loaded axles. This allows us to provide a higher clamping force in an emergency.

  • Fixing round rods of all types, in any position
  • Clamps from standstill, also for braking from movement in the event of an occasional accident
  • Clamping force without energy supply for an unlimited time
  • Fixes axles precisely in the event of power failure, drive or control errors
Used in
  • Presses & punching machines: Prevents lowering/sinking of the upper part, protects tools and operating personnel
  • Machine tools: Reliably secures heavy vertical axles and spindles against falling.
  • Robotics & portals: Holds tools and loads securely in position, even in the event of drive failure
  • Intralogistics & lifts: Guarantees safety for people and goods in lifting systems
Used in
  • Presses & punching machines: Prevents lowering/sinking of the upper part, protects tools and operating personnel
  • Machine tools: Reliably secures heavy vertical axles and spindles against falling.
  • Robotics & portals: Holds tools and loads securely in position, even in the event of drive failure
  • Intralogistics & lifts: Guarantees safety for people and goods in lifting systems

Functional principle of the safety catcher
The clamping unit for mechanical restraint device

The safety catcher operates mechanically according to the functional principle of frictional contact. When unpressurised, the holding load builds up via the conical clamping system as the load sinks. The self-reinforcing principle comes into effect, locking the rod.

(1) Securing load (2) Locking
Schematic representation of the safety catcher, securing load & locking

Securing load

When the release pressure drops, the spring-loaded clamping segments rest against the rod to be clamped. The resulting friction force secures the load, and the safety catcher is ready to take over the load.

Locking, take over load

If the rod to be clamped moves in the direction of the load, the clamping segments shift due to friction until they reach the internal stop. This leads to a self-reinforcing locking of the system. As a result, the holding load builds up, and the load is taken over.

(3) Releasing
Schematic representation of the safety catcher, unlocking

Releasing

Hydraulic or pneumatic release pressure pushes the release piston, together with the clamping segments, upward from the “securing load” state into the released position.

In the locked state, in addition to the release pressure, an external force must be applied to the clamped rod in the opposite direction to the load.

Load and overload

Once the load is taken over, the rod holds securely as long as the maximum permissible holding load is not exceeded.

An overload causing the rod to slip through may occasionally occur without damaging it or the safety catcher.

Mounting the safety catcher
Mounting compressive load or tensile load

Compressive load

With the compressive load mounting type, the safety catcher rests on the machine bed and transmits the holding load directly. It can be fixed from below with axial threaded holes.

If a screw mounting from the underside of the machine cannot be implemented structurally, collar flanges offer an alternative.

Safety catcher as compressive stress
Tensile load

With the tensile load mounting type, the safety catcher is installed in a suspended position: It is connected directly to the machine bed using cylinder screws. In this case, the screws transmit the holding load.

For versions without an integrated mounting flange with screw holes, mounting must be implemented using a collar flange.

Safety catcher as tensile stress
Collar flanges

Fixed mounting flange
In addition to the centering collar permanently mounted on the safety catcher, a fixed flange can be used. When in use, make sure that the safety catcher is installed without any stress.

 

Loose mounting flange
In addition to the centering collar permanently mounted on the safety catcher, a loose flange can be used. This enables both radial and vertical movement compensation.

Loose mounting flange
Clamping heads with DGUV-Test certificationAll safety catchers are DGUV-Test certified: Take a look at all of our DGUV-Test clamping units!

Sensors of the safety catcher
Inductive proximity switches and pressure switches

The safety catcher can optionally be equipped with up to 4 independent sensors: Depending on the required performance level of the machine into which the safety catcher is integrated, the proximity switches can be provided in a redundant version or with a diagnostic output if required.

Load secured
Switch 1

The inductive proximity switch is a normally open contact that detects the lower edge of the clamping segments. It is closed when the load is secured.

Released
Switch 2

The inductive proximity switch is a normally open contact that detects the upper edge of the clamping segments. It is closed when the clamping segments are at the upper stop.

Locked
Switch 3

The inductive proximity switch is a normally open switch that detects the lower edge of the clamping segments. It is closed when the clamping segments are at the bottom stop.

Load secured
Pressure switch

The pressure switch is open when the system is depressurised. This detects whether the safety catcher can secure the load.

 

Configure your clamping unit - safety catcher.Here you will find data sheets with detailed mounting dimensions and can request CAD data.

Technical data of the safety catcher
Released by hydraulic or pneumatic pressure

SAFETY CATCHER
FOR VERTICAL AXLES
+ Locking
+ Certification
Self-reinforcing
DGUV Test
Rod-Ø
(mm)
Permissible
load
(kN)
Installation
length1 
(mm) 
Installation
length2 
(mm) 

Installation diameter
(mm)

  25 10 152  155  71
  28 15 169  82
  40 33 211  214  106
  50 52 264  125
  56 67 262  265  140
  63 100 285  290  160
  70 107 302  172
  80 133 322  325  194

1 Compressive load without centering collar
2 Tensile load with centering collar

The values given apply to all fluids.

The holding load of the safety catcher for machines has a safety factor of at least 2, but does not exceed a safety factor of 2.8.

  • Compressive load or tensile load
  • Hydraulically released: min. 40 bar, max. 250 bar
  • Pneumatically released: min. 4 bar, max. 10 bar
  • Factory check of the safety catcher required after 2 million switching cycles
  • Max. rod speed: 0.5 m/s
  • Working temperature: 0 °C to +60 °C
  • Fluids: mineral oils, HFC or compressed air, others on request

Various mounting flanges and sensor technology components are available as accessories. A functional rod with freely configurable piston rod ends can also be configured in the HäKo online product configurator.

Configure a clamping unit now.You can use our HäKo to individually configure your safety catcher.
To use the safety catcher as a safety component, you can request the B10D value from us to determine your performance level.
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