Industrial Robots Crush Workers
On the Scene E-Newsletter, Edition 132, February 14, 2011
What does the term “industrial robot” mean? In 1979, the Robot Institute of America described it as: “A reprogrammable, multifunctional manipulator designed to move material, parts, tools, or specialized devices through various programmed motions for the performance of a variety of tasks.” Typical uses for industrial robots are material handling, automated assembly, and other labor-replacing tasks in such manufacturing settings as semiconductor, electronics, telecommunications, pharmaceutical, food processing and automotive industries. Today, many manufacturers use these multifunctional manipulators instead of humans to perform unsafe, hazardous, repetitive tasks with a high degree of accuracy. These programmable, mechanical robots get the job done but on occasion injure workers.
CED engineers have indicated that a majority of robot incidents investigated occur during non-routine operating conditions. Safety in terms of industrial robots usually consists of isolating the workspace of the manipulator from workers by a safety guard with locked safety doors or light barriers. Once the safety door is opened or the light barrier is crossed, the robot is stopped immediately. Workers suffer injuries while programming, maintaining, setting up, or adjusting the industrial robots. During these functions, the worker must enter the robot’s working area, exposing him/herself to risk.
An example of this occurred when a worker was crushed while dislodging packing material from a robotic arm moving pallets onto a conveyor system. Even though he shut down and locked out the robotic arm, when the material was dislodged, the conveyor system restarted. Standing within the robot’s working envelope, the worker became trapped between the conveyor and the robotic arm, crushing him. In another instance, while working on a robot-conveyor arm, a technician forgot the machine cycled every 15 minutes. Since the technician had not turned-off the machine, it pinned him between the robot arm and conveyor. Many other workers shut down a machine while trying to clear a jam; however, if the machine is not equipped with a lockout system, someone else can restart the machine. When the jam clears, the robot can cycle and may cause severe crushing injuries.
How can these incidents be prevented? CED believes employers must (1) supply adequate training and implement safe work practices, (2) ensure guards and other safety systems remain in place and are not bypassed, and (3) install signs, audible horns and/or visible lights as warning devices to make people aware of hazards so they can avoid accidents. Employees need to (1) keep guards and safety mechanisms in place, (2) follow safe work practices, and (3) keep their focus on the task at hand.
To further minimize the chance of robotic accidents, we have seen developments in robotic safety in the area of safe motion technology which creates safety zones for different operational and maintenance situations.
But in spite of these innovations, accidents still occur. CED can help. We not only understand robotic standards, safety, and warning issues but have engineers on staff that helped develop safety standards for Manufacturing Systems /Cells – that include industrial robots. The ANSI standard assigns responsibility for industrial robot safety to manufacturers, integrators, installers and the user.
Call us when you have a question. CED’s goal is to assist you in finding the correct answer. For more information on CED or how we can assist you on your current or next case, please feel free to contact one of our case managers at firstname.lastname@example.org or call 1(800) 780-4221.