Exclusive Press Safety and Clamping Devices for Power-Off Protection
Advanced Machine & Engineering is the exclusive North American provider of SITEMA® Safety Solutions—a globally recognized line of clamping units and linear brakes that act on round rods. SITEMA (based in Germany) is the only company in the world specializing exclusively in this field of rod clamping and braking technology, a focus that has made them the international leader in safety catchers and clamp units. With SITEMA’s products, you can equip your machinery with devices that automatically secure loads during power loss, provide redundant safety for vertical axes, and deliver precise locking for positioning tasks. From preventing a press ram from free-falling to holding a robotic arm in exact position, SITEMA solutions cover a wide range of applications where uncontrolled movement is not an option. We have partnered with SITEMA since 1992, bringing decades of expertise to our customers in applying these safety devices effectively.
SITEMA safety solutions add an essential layer of protection and control to machinery—catching gravity-driven loads, locking moving axes on demand, and enabling safer, more controlled operation in manufacturing, automation, and material handling environments
SITEMA's SiForce Technology introduces a self-intensifying clamping mechanism that enhances safety and efficiency in press operations. Unlike traditional spring-actuated systems, SiForce utilizes the load's own force to increase clamping strength, ensuring that the clamp tightens as the load increases. This design offers several key benefits:
Spring or mechanical wedge mechanisms automatically clamp the rod when power or pressure is lost, ensuring fail-safe load holding.
Meets global safety standards including OSHA and DGUV approvals, giving you confidence in safe operation of vertical loads.
Engages and disengages repeatedly, integrates with pneumatic or hydraulic systems, and easily resets for regular machine use.
Adapts to everything from small pneumatic cylinders to massive hydraulic presses, with options for static or dynamic load holding.
High-strength steel, quality coatings, and proven performance over decades ensure durable performance in even the harshest conditions.
SITEMA safety catchers have been evaluated according to OSHA Directive CPL 02-01-043. OSHA has determined that the SITEMA safety catcher meets all of the requirements of the directive.
A step-by-step guide shows how to replace the seals in an RCH Hydraulic Rod Lock unit from AMLOK.
Spider-Man is now swinging all over the New York stage during his new Broadway production at Foxwoods…
Typical travel without the optional Spring Base is between 5 and 15 mm…with the spring base, an additional 6-10 mm depending on the size. Full travel with the spring base option can range between 10-25 mm depending on type and size. If the catcher does not bottom out/compress the Spring Base fully, then release pressure can be applied and unlock the catcher without an upward movement.
If the safety catcher is holding a load? You must first apply release pressure and then move the axis upward. At this time, you should be monitoring the “Unlocked” proximity switch indicating the status condition.
The typical reaction time of the SITEMA safety catcher is approximately 150 m/sec.
All mounting bracketry should be designed for 4 x M in the event of an overload condition.
No, the influence of mineral oil on the shaft is insignificant and you will not lose holding capacity.
Admissible Load (M) sizing is determined by the platen weight + tooling weight and anything mounted to the platen.
Factor of 100% is included. Minimum holding is 2 x M (admissible load) max holding is 3.5 x M. Force test required is 1.5 x M.
No, the clamp system requires approximately ½ inch of downward movement to develop full holding. The safety catcher’s are single acting and only hold against gravity.
* In case impact noises due to excess pressure are audible when pressurizing the safety catcher, these can be suppressed by means of a flow control valve in the p-line.
** In case the pressure is not sufficiently constant (e.g. pressure drop at the beginning of a downward stroke), we recommend a check valve in the p-connection of the valve.
To keep the clamping permanently open, safety catchers mostly are hydraulically actuated. Pneumatic versions are also available for smaller units.
In most applications an actuation as suggested in Fig. 2 is used. During every operational cycle, the 3/2-way valve is actuated electrically and releases the safety catcher.
In all other operational conditions, as well as in cases of power-failure, pressure line breakage, emergency stop, etc. the safety catcher becomes effective, secures the rod and/or stops the load. If necessary the valve can also be switched by another safety signal, e.g. speeding, contouring error, etc.
Proximity switch 1 “load secured” signals the secure state and is used to authorize entrance to the danger zone.
Proximity switch 2 “clamping release” is used to activate the movement of the drive in the load direction.
For automatic detection of failures both signals are compared. In case both switches indicate the same state—apart from minor overlapping periods—there is a defect present.