Safety Mat Switches and Safety Edges and Bumpers
Rugged Omron Scientific Technologies, Inc. Universal Safety Mats guard machine operators against some of the potential hazards and dangers of the modern manufacturing environment.
An Omron STI Universal Safety Mat system (UM series safety mat combined with an MC3, MC4, or MC6) offers a simple method for guarding personnel around hazardous machines. A safety mat system offers freedom, flexibility, and reduced operator fatigue when compared with traditional guarding methods such as interlocked fences, pullback restraints or perimeter barriers. Full visibility of and access to the work area is maintained.
The operation of the safety mat is easy to understand. The safety mat is a simple, normally open switch. When a specified minimum weight is applied to the safety mat the “switch” closes. This sends a signal to the safety mat controller, which in turn, sends a stop signal to the guarded machine. Each safety mat presents four wires to the safety mat controller. This provides the redundancy required to monitor the wires for open circuits due to incorrect wiring or physical damage to the safety mat wires.
Additionally, safety mats can also simplify routine tasks such as machine set-up, maintenance, and repair. Typical applications for safety mats include:
- Welding Robots
- Assembly Machinery
- Material Handling
- Packaging Machinery
- Robotic Work Cells
Safety Edges, Bumpers, and Mounting
The safety edge or safety bumper are flexible strips which can be fixed to the edge of a moving part such as a machine table or powered door where there is a risk of a crushing or shearing hazard.
If the moving part that includes the safety edge or bumper strikes operator (or vice versa) the flexible safety edge is depressed and will send a signal to the power source to stop.
A safety edge or safety bumper can be classified as a “trip” device. The safety edge or bumper does not restrict access but will only “sense” it. Both the safety edge and the safety bumper rely entirely on their ability to both sense and switch for the provision of safety, therefore, it is important the control circuit for the safety edge or safety bumper be control reliable. In general, the safety edge and safety bumper should only be used on machines which stop immediately after removal of power.
The safety edge or safety bumper along with a controller, make up a versatile and flexible emergency stop system for use in applications where a machine operator or set-up person must have easy, contiguous access to an E-Stop actuator.
A complete safety edge consists of an aluminum rail, the safety contact, and the safety contact strip. The special shapes of the safety edges (rubber profile) protect the safety contact strip from damage and allow actuation angles for the safety edge to exceed 90 degrees.
Safety bumpers operate in the same manner as the safety edge with the only construction difference being the addition of foam rubber covered in polyurethane to protect any object that comes in contact with the safety bumper. Safety mats and edges are sold into many markets. Robotic and industrial manufacturing applications comprise the largest markets.