Abstract: A multivariable process monitor and method of monitoring a resistance spot welding process to yield instantaneous information on weld quality during the weld cycle. Sensors on the machine measure welding input variables and workpiece response variables and provide signals to a microcomputer system. A simplified analytical model of the spot welding process is incorporated in the microcomputer and is the reference for the weld quality logic that accepts or rejects the weld. Faulty welds are diagnosed and the reason displayed.

Abstract: The surface of the molten weld pool and surrounding workpiece area are floodlighted during an arc welding operation by a narrowband light source such as a laser in order to highlight the pool boundary and yield an image which is easily computer processed to give the pool perimeter. An arc welding torch has built-in optical systems, one to route laser energy via a coherent optical fiber bundle to exit optics on the torch to project two spots of light onto the trailing side edges of the pool, another to image the weld region which is relayed to a remote camera. The difference between reflectance values and direction on the pool and workpiece surfaces accounts for the enhanced image.

Abstract: An improved grate construction for a fixed bed coal gasifier comprises an interrupted generally cylindrical platform including a plurality of sector-like portions and rotatable means, e.g. a stirrer, mounted for rotation adjacent the upper surface of each platform portion. The upper surface of each portion is inclined upwardly in a circumferential direction to an upper leading edge thereof from which an upright wall depends. The stirrer is rotated in the opposite circumferential direction for cooperating with the depending walls to reduce the size of clinkers and for promoting movement of solids from the shaft over the platform.