Abstract: Arc welding apparatus for use in conjunction with conventional link forming apparatus is operable for welding the closed ends of a link after it is formed. The electrode is mounted on a swinging arm which presents the electrode from the front of the assembly and positions the electrode substantially over the top of the link for welding thereof. The vertical, horizontal and angular positions of the electrode are adjustable by means of threaded adjustment knobs. A shield and gas tube are mounted adjacent to the tip end of the electrode and move simultaneously with the electrode into position over the link during a welding operation.

Abstract: An automatic stone setting machine includes a vibratory parts feeder which orients the stones in the correct position for pick-up and a pick-up quill which is capable of sensing the position of the stone on the end of the quill. The vibratory parts feeder includes an escapement having a v-shaped track, an aperture at the end of the track and a cover plate mounted over the track. The track and cover plate cooperate to create a passageway which only allows correctly oriented stones to pass through to the pick-up point. The pick-up end of the pick-up quill has an inwardly tapered side portion, a flat seat at the inner end of the tapered side portion and four circumferentially spaced vacuum ports located in the tapered side portion. The flat seat receives the top of the stone and the tapered side portion receives the angled side faces of the stone which block the vacuum ports. A vacuum sensor is provided to sense the level of vacuum applied through the vacuum ports.

Abstract: A resistance welding apparatus includes a power supply, a pair of welding electrodes and a welding circuit which is operative for controlling the operation of the electrodes to effect a welding operation. The welding circuit is operative for controlling the operation of the electrodes so that a welding operation can only be carried out on a workpiece assembly in the event that the resistance in the circuit path between the electrodes is within a range which is not likely to cause arcing between one or both of the electrodes and the workpiece assembly. The welding circuit further includes a current comparator for controlling the level of the current passed through the electrode during a welding operation.

Abstract: A method and apparatus provides a three dimensional measurement of a point on an object. A surface with a system for detecting the position of sensors is placed adjacent to the surface and an assembly disposed adjacent to the surface yet freely movable within a plane is parallel to the surface. The assembly includes two sensors whose orthogonal projections into the surfce are detected by the two dimensional detecting system. The assembly further includes a probe, slidable only in a direction perpendicular to the surface and a system for detecting the perpendicular distance of the probe from the surface. In this manner, the orthogonal projection of the probe into the plane is permanently fixed in relation to the two sensors. In practicing the method of the invention, the object to be measured is placed adjacent to the surface and the assembly is moved to a position where the contact on the probe can be moved orthogonally until it contacts the spot on the object whose position is to be measured.