Abstract: A welding torch for gas tungsten arc welding, the welding torch including a torch head and a torch handle. The torch head includes a hollow inner body in electrical contact with one terminal of an electric power source, the inner body having an interior through which an axially positioned electrode extends, a free end of the electrode projecting beyond an electrode contact region of the inner body, and there being an inner gas chamber defined above the contact region within the interior of the inner body about the electrode. The torch head also includes a collet that provides the contact region where the inner body is in positive electrical contact with the electrode above the electrode free end, a gas shroud extending around but spaced from the electrode free end to define an outer gas chamber that allows, in use, gas to shield the electrode free end, and means for circulating coolant about or above the contact region to extract heat from the contact region.

Abstract: A welding torch for gas tungsten arc welding, the welding torch including a torch head and a torch handle. The torch head includes a hollow inner body in electrical contact with one terminal of an electric power source, the inner body having an interior through which an axially positioned electrode extends, a free end of the electrode projecting beyond an electrode contact region of the inner body, and there being an inner gas chamber defined above the contact region within the interior of the inner body about the electrode. The torch head also includes a collet that provides the contact region where the inner body is in positive electrical contact with the electrode above the electrode free end, a gas shroud extending around but spaced from the electrode free end to define an outer gas chamber that allows, in use, gas to shield the electrode free end, and means for circulating coolant about or above the contact region to extract heat from the contact region.

Abstract: The present invention provides an apparatus for pressure sensing. The apparatus comprises a series of Bragg gratings and a light guide incorporating the series of Bragg gratings. The apparatus also comprises a plurality of moveable wall portions having opposite first and second sides. Each moveable wall portion is positioned so that a change in pressure at one of the sides relative to a pressure at the other side will move the moveable wall portion that is coupled to respective Bragg gratings so that the movement of one of the moveable wall portion causes a force on the respective Bragg grating resulting in a change in strain of the respective Bragg grating. An internal space at each Bragg grating is in fluidal communication with an internal space at an adjacent Bragg grating whereby pressure differences between adjacent internal spaces are reduced.