Manually operable paper slitting device and method
Method and apparatus for cutting electrical outlet openings in p
Method and apparatus for locating utility structures behind cons
Method for operating a plate system for stamping presses and...
Method for perforating roofing sheet material
Method of making a tear line-forming perforation in a sealed mar
Method of making an aerator membrane
Method of perforating a texture to be sewn
Method of producing mat with valves therein