Abstract: The present invention relates to a spot welding inspecting apparatus for inspecting a weld between two metal plates which are subjected to spot welding without destroying the metal plates or weld. A pair of knife gauges having an interval therebetween larger than the diameter of the weld are inserted between the welded metal plates by a continuous impact of the hammer which is driven by a compressed air and pushed between the metal plates so as to clamp the weld. Thereafter, the piston is moved so that the knife gauges may approach the weld to indicate the distance between the knife gauges with the index.

Abstract: A document feeder for use with an image forming device such as a copy machine. An original document is first transported from an original document feed port toward an original exit port until a trailing end of the original passes a predetermined stop position whereat an imaging operation is to be carried out. By transporting until the trailing end passes the stop position, there is time for a previous original to exit from the original exit port. Then the original document is fed back toward the original feed port until the trailing end of the original is properly positioned so that the document can be imaged.