Multi-functional sensing methods and apparatus therefor

摘要

A method and apparatus for sensing a pierce-through condition of a material made by a piercing force in which a shield surrounding a source of the piercing force is supplied with a gas supply to create a pressure within the shield means. A decrease in pressure caused within the shield by a pierce-through condition created by the piercing force is then detected. A method and apparatus for detecting the distance between a nozzle assembly for a machining process and a workpiece to be machined in which gas is supplied to a shield surrounding a nozzle assembly. An increase in pressure in the shield is detected as an open end of the shield approaches a workpiece to be machined. A method and apparatus for obtaining and maintaining a predetermined gap distance between nozzle assembly and a workpiece for a machining process are provided by further detecting when the pressure within the shield means reaches a pressure corresponding values and ranges. A method and apparatus for determining the thickness of a workpiece is further provided by comparing an established nozzle assembly position with a predetermined reference position.