Large machine tools such as planer mills often are installed partially below floor level, resulting in potentially hazardous pits. Workers must remove pit grates or slats to service the machine. Here, metal roll-up, walk-on covers offer an alternative. Typically made of reinforced stainless steel, these covers allow partial pit access while preventing falls at other times or into other pit areas.
Case in point: One aircraft manufacturer uses large fiber placement machines to build fuselages from composites. Adjustable tailstocks of the two-station machine travel on guideways located in a pit below floor level. Production workers must access workpieces as they’re produced, necessitating pit covers during production, yet also requiring a way to remove the covers for repairs and adjustments. Grating is time-consuming to move, and slats require complex support structures that complicate maintenance tasks. Instead, the aircraft manufacturer uses rugged walk-on metal pit covers with extruded aluminum stiffening ribs bonded to stainless steel sheets; there are no hinges to collect debris. These roll up onto steel rollers equipped with take-up mechanisms.