Thanks to the PSDI (Presence Sensing Device Initiation) function in the Flexi Soft safety controller, it is possible to control the press cycle in manual insertion presses using a type 4 safety light curtain in PSDI mode. As soon as the worker removes his or her hand from the hazardous point, the press automatically restarts. Not only does this remove the need for two-hand control devices, it also offers clear benefits when it comes to providing workers with ergonomic, safe workstations – and ensures that more of the machine capacity is utilized.
(Note: The following video includes European standards; consult a safety professional to discuss your specific application and standards in your country.)
When using a conventional two-hand control device, workers are required to actuate the two control elements simultaneously using their hands in order to trigger the dangerous movement, such as the working stroke of a press. The circuit has to stay activated until the press cycle – and, therefore, the dangerous movement – is complete. Only then can the worker pick up the next workpiece. This procedure can have a negative impact on workstation ergonomics, leading to more errors and a drop in productivity as a result. There is also the risk of accidents in the event that a worker makes accidental contact with the circuit.
A pneumatic press provides an example of a simple way in which the PSDI function can create a long-term increase in productivity. As workers have both hands free, they are able to pick up the next workpiece as soon as they have placed the first one in the press. There is no need for the press cycle – or the dangerous movement – to be completed fully. The PSDI function thus represents a step that, although simple, enables much more of the machine’s capacity to be utilized and productivity to increase significantly as a result.
Safety and more
Safety solutions for machines and plants nowadays have to do more than “just” protect against accidents – we are increasingly seeing the need to offer added value with respect to automation engineering. Extensive application knowledge, a broad-ranging product portfolio, safety controllers that are ideal for the task at hand, and the right advice from the very start of the project are the keys to this, even when using PSDI in presses.
