Abstract: An electrical resistance welding gun includes a hydraulically or pneumatically actuated clamping device for forcing workpieces into contact with one another, and a device for preloading and maintaining loaded contact between welding electrodes located on opposite sides of the workpieces. The electrodes are preloaded by a compression spring whose force is entirely independent of the action of the hydraulically-catuated clamping device. The electrode is supplied with electrical welding power and is cooled by circulating coolant through the electrode. A piezo-electric sensor provides an indication of the electrode biasing force and of changes in this force during welding. The force signal from the sensor may be used for feedback control of weld current and length of the period during which weld current is applied. The initial electrode force is easily adjustable by changing the effective length of the spring.

Abstract: A method is disclosed for controlling a high energy radiation beam to produce a melt zone with parallel sides in a workpiece having first and second opposed surfaces between which the zone extends. The method comprises (a) directing the beam at a slight angle to the normal through the first surface of the workpiece with the focus of the beam being at or adjacent the second surface; (b) oscillating the beam and workpiece relative to each other about a point located on the beam axis at or adjacent the first surface and in a plane perpendicular to the lateral line of advancement of the directed beam so that opposite sides of the melt zone in the plane will each be sequentially rotated to assume an orientation substantially perpendicular to the first surface; and (c) laterally advancing the directed beam along a on the first surface of the workpiece while carrying out the oscillations of step (b) at a selected frequency above a minimum.

Abstract: Energy is extracted from a free-stream fluid flow of wind or water by means of a multi-turn helicoid structure with a relatively small pitch angle. The axis of the structure about which the helicoid turns is making an angle with the flow vector in the order of or slightly larger that the pitch angle. Several such helicoid structures are combined with their radii overlapping, for the most effective interception of a certain cross sectional area of the fluid flow. Mile-long helicoid walls may be erected in this fashion. Using groups of helicoids which alternately turn clockwise and counter-clockwise all gyroscopic forces, which appear when the structures are turned to follow changes in the direction of the flow, are internally balanced. An omni-directional structure is also described which need not be turned when the flow direction changes. It is obtained by adding flow-diverters surrounding a helicoid structure with vertical axis.

Abstract: A spot weld control senses differences in welding current required to produce an optimum weld by determining the time rate of change of resistance during the increasing resistance portion of the weld cycle. The weld control can reduce the welding current if the time rate of resistance change exceeds a maximum value and increase the current if the resistance change is less than a minimum value. The weld current may be terminated when a decrease in resistance from the peak resistance value has reached a predetermined percentage of the peak resistance value or terminated after a predetermined number of current cycles.

Abstract: A high voltage power supply used to transfer three-phase a.c. energy to d.c. at full rated power over a large range of output voltages. The electric and magnetic circuits are arranged according to the core type of construction wherein three legs of the iron core extend axially and have the primary coil wound along their full length. The core legs are joined for magnetic circuit continuity at the extremities. A plurality of high voltage decks each having three secondary winding modules mounted and interconnected are stacked axially over the axially extending iron core pieces. The secondary coils on each high voltage deck are interconnected in several three-phase connections, to produce a phase shift in the ripple of the d.c. output voltage of the various decks. A high voltage bridge rectification circuit mounted on each deck produces full wave rectification of the ouptut.

Abstract: An electron beam position control for maintaining the position of a beam of charged particles that strikes a workpiece at an impact spot includes an adjustable aperture through which X-rays emanating from the impact spot pass, a rotating cylinder having a plurality of slots formed on its outer surface, a scintillator crystal and photo multiplier located within the rotating cylinder, an electronic circuit for producing an error signal that energizes one or the other of two magnetic coils, which are effective in redirecting the electron beam so that its focal point strikes the workpiece at the target or reference position.

Abstract: A method is disclosed for joining two or more pieces of metal along a seam line by directing a jet of liquid metal onto the seam, the surfaces of which, at the seam region of the metals to be joined, have been pre-melted just before the liquid metal jet is poured on, the pre-melting being done by an energy carrying beam of radiation, e.g. an electron beam or a laser beam, of high power density, a mixture of molten metals thus being formed which thereafter will cool, solidify, and thereby join the various metal pieces into a single welded structure.By making the power and power density of the radiation beam used for pre-melting sufficiently high, only a thin surface layer is melted rapidly; it will adhere to the underlying solid interface by natural adhesion. On account of the rapidity of the melting only a minimum of the beam energy is lost by heat conduction. No beam energy is used up for melting the liquid metal jet; the latter also acts as filler for any size of gap in the seam area.