Keeping It Closed – Hard Stop and Interlocking Door Safety Features
A safety interlocking system is important for any robotic work cell. By incorporating hard stop and interlocking door safety features into your work cell, you are ensuring that no worker is going into the robot’s area when the robot is in operation. This, along with proper training, will keep your workers safe and free from robot-related injuries.
So, what are these features? A hard stop feature is made up of a zone ring and two zone switches. This zone ring is attached to the base of the robot and has two zone switches connected to it, one on either side of the robot. These features are connected to the base of the robot so that the switches can communicate to other areas of a work cell, like the doors, when a robot is in operation.
Basically, if a robot is moving without being in teach mode (and without someone holding the teach pendant), a human cannot be in their space. For example, if a robot is in zone A and it has to move to zone B to work on a project, but a human is in zone B, there are safety measures in place to ensure that the robot cannot move into that area. The hard stop feature is what makes the robot stop when the interlocking doors are opened.
But, what are interlocking doors, you ask? That is simple. Interlocking doors are doors that have switches that channel back to the zone switches on the robot. The zone switches control zone A or zone B. Before the robot can move to zone A, the interlocking door for zone A needs to be closed. If the interlocking door for zone A is opened at any time while the robot is performing its application, the robot will perform a hard stop. In order for the safety violation to be fixed, the door must be closed. Then, the technician needs to reset the robot, and it will be safe to resume operations again.