automatic locking device造句

When I worked with such a system a few years ago-everyone who entered the room when it was turned on had to go through a 30 hour laser safety course-the doors had to have automatic locking devices to stop people coming in when the laser was turned on-and there were all manner of handrails and such stopping people from going where the laser was operating.
It's difficult to find automatic locking device in a sentence. 用automatic locking device造句挺难的