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Don't Get Caught in a Machine Safety Accident: 4 Types of Machine Safety Input Devices

7/26/23  |  Dave Cucerzan, Product Specialist

The importance of safety in your operations cannot be overstated, and we know it’s top of mind for you. Among the many safety focus areas, machine safety is critical to ensuring your employees are safe. One key aspect of this is safety input devices, which act as sensors and interfaces, enabling operators to use the machines while staying injury free.

This post explores four types of machine safety input devices: presence-sensing safety devices, safety interlock switches, emergency stop and trip devices, and operator interface devices.

Let’s begin!

1. Presence-Sensing Safety Devices

As the name suggests, presence-sensing safety devices create a virtual boundary, or safeguarding zone, around the machine. If someone or something enters this zone, the device triggers a safety response to protect the operator from harm. Common types of presence-sensing safety devices include:

  • Light curtains
  • Laser scanners
  • Pressure-sensitive mats
  • Pressure-sensitive edging

These safety devices don’t require physical interaction between the device and the operator or object, meaning it enhances safety while also maintaining productivity.

2. Safety Interlock Switches

Safety interlock switches are widely used in industrial environments to physically interlock guard doors or systems. These switches make sure that operations are stopped or modified when a guard door is open to prevent access to hazardous areas. These switches come in both non-contact and physical interlocking version, depending on the specific requirements of the application.

Non-contact safety switches use proximity sensing technology for seamless and non-intrusive operations. Physical safety switches use mechanisms to physically lock guard doors closed. In some cases, key-exchange systems are used to enhance security further and prevent unauthorized access.

Examples of safety switches include:

  • Tongue interlocks
  • Hinge-operated interlocks
  • Guard-locking interlocks
  • Non-contact interlocks
  • Safety limit switches
  • Trapped key systems

3. Emergency Stop & Trip Devices

Emergency stop and trip devices are crucial to worker safety because they provide a quick and reliable way to stop a machine in an emergency. They’re designed to be easily accessible and visible, allowing operators to act immediately when needed.

Types of emergency stop & trip devices include:

  • Emergency stop buttons
  • Cable pull safety switches

Emergency stop buttons are large, highly visible buttons that, when pressed, will immediately stop the machine. Cable pull safety switches involve a rope or cable that can be pulled from any point along the machine to stop it. These devices are a quick and effective way to stop a hazard, prevent accidents, and reduce the severity of potential injuries.

4. Operator Interface Devices

Operator interface devices give operators the ability to control and monitor a machine to ensure worker safety. These devices often involve physical actuation or capacitive touch technology, depending on the specific application requirements.

Types of operator interface devices include:

  • Enabling grip switches
  • Two-hand controls

Enabling grip switches require operators to maintain a grip on the device to keep the machine in operation, adding a layer of safety by preventing accidental activation. Two-hand controls require simultaneous activation of both hands to start a machine operation, keeping the operator’s hands away from harm.

We Can Help!

Rexel’s safety experts have deep knowledge of machine safety and know the ins and outs of what safety input device is best for your operations. They can also conduct full safety assessments of your facility to ensure that your workers are safe, and you can maintain efficient and productive operations. Ready to get started with a safety assessment? Not sure which machine safety input devices are best for you? Contact us today!