What Is a Safety Device?
A safety device refers to components that enhance safety in automated equipment. These devices are crucial when operating machine tools or manufacturing equipment that involves large movements, significant forces, or rotating parts, as they mitigate the risk of accidents, such as entrapment. Commonly, safety measures include enclosing equipment within a safety fence to prevent direct access.
Nevertheless, a safety fence alone may not suffice if workers inadvertently open the fence and approach the equipment. To address this, many machine tools and manufacturing setups integrate safety devices that halt operation if the safety fence is breached. These components are what constitute safety devices within safety equipment.
Uses of Safety Devices
Safety devices are integral to manufacturing equipment and machinery with high accident risks, ensuring safety protocols are observed. For instance, large robots operating at high speeds in mass production lines pose potential injury risks to workers due to the lack of human detection. Employing safety devices like door switches on safety fences and sensor-based equipment, such as light curtains, minimizes these risks. These devices, often referred to as “interlocks,” ensure equipment ceases operation upon the opening of a door or cover.
Principle of Safety Devices
A common example of a safety device is the door switch. It operates by having switches on either side of a door, disrupting the electrical circuit when open and completing it when closed. Door switches come in mechanical forms, where contact is made by a physical connection, and non-contact forms, which utilize a magnet within an actuator to operate reed switch contacts. This magnetic approach avoids the need for direct contact, offering versatility in applications. Unlike circuit-interrupting safety devices, analog solutions like covers or lids physically block access to moving parts, further enhancing safety.
Incorporating an emergency stop button, independent of the main control system, is essential for immediate halts in emergencies, ensuring operational safety even if the main control system fails.
Types of Safety Devices
Common safety devices include:
1. Safety Switches
Used for machine operation control, allowing emergency stops. Examples include emergency stop switches and foot switches.
2. Safety Sensors
Monitor proximity around machines or detect a door or cover status. Photoelectric sensors and proximity sensors are typical examples.
3. Safety Speed Control Device
Control machine speed to reduce accident risks, adjusting speed according to work conditions.