1. Summarize the case
At an employer's automotive component manufacturing facility,manufacturing operations make extensive use of robots locatedwithin fenced cages. At one location, suspension parts aretransferred by rotating tables from station to station whilegreasing and other operations are performed on the parts by robots.If necessary, employees can gain access to the robots by enteringthe cages through electrically interlocked gates. When the gatesare opened, the multiple energy sources that power the robots,rotating tables, and related machinery are turned off but are notdeenergized or locked out. An employee who is inside a cage when arobot is activated could be struck by the robot arm or othermachine parts and seriously injured.
An injury occurred when an employee, consistent with the employer'spractices, entered the robot cage without deenergizing or lockingout any equipment. The employee was attempting to unjam a robotarm. In freeing the arm, the employee tripped an electric eye,causing the robot arm to cycle. The employee's arm was struck bythe robot and injected with grease. The employer contends thatlockout procedures were not necessary because once the gate isopened, movement of the robot arm is impossible, and a maintenanceworker inside the cage would have ample warning – by the closing ofthe interlocked gate – before the machinery started up, to avoidinjury. According to the employer, once the interlocked gate isopened, it must first be closed and a number of buttons must bepushed before any machine movement can occur. The startup procedurewould take some time and the person inside the robot area would beaware of the closing of the gate and the presence of another workerat the nearby control panel.
