Abstract: A gas plasma generating system includes a resonant cavity for connection to a source of very high frequency power. A plasma cavity is defined by a wall of an electrically nonconductive material positioned within the resonant cavity for containing an ionizable gas such that in use a plasma is formed in the plasma cavity, the cavity having an exit opening to enable plasma to exit from the system. The plasma cavity comprises a tubular member extending through opposed walls of the resonant cavity, the tubular member receiving at one end a plasma gas, in use, and plasma exiting from the other end, and a movable tuning member whose position can be adjusted to achieve the desired tuning condition, the tubular member defining the plasma cavity extending through the tuning member.

Abstract: An automatic corrosion measurement system and method enables rapid measurement and evaluation of corrosion on significant portions of straight and curved pipe sections and other surfaces from several square inches to several square feet, using a laser instrument which projects laser light across a scan area which includes corrosion, and detects reflected laser light therefrom. A positioning mechanism advances the laser instrument along the surface to permit evaluation of a large area, and a processor controls both the operation of the laser instrument and positioning mechanism. Automatic processing by the processor converts surface condition signals into readily usable output in the form of displays, printouts or maps, for immediate use.

Abstract: A process for obtaining long, continuous, thermoplastic welds on large structures. A series of tabs are used in pairs and especially in alternating, overlapping pairs to obtain resistance heating of a strip material placed in the bond line. The resistance of the tabs is less than that of the strip material. Conducting braid-tubes afford continuous welding when the bond line is curved. Alternatively, an electromagnetic field is used to take advantage of the induction heating. A wide susceptor is used to weld a current conducting substrate while avoiding bulk heating of the substrate. The unexpected property of current-conducting braid-tube susceptors, in which induction heating takes place at the center rather than at the edges of a flattened braid-tube susceptor, is used to obtain long continuous curved welds.

Abstract: A portable personal computer that utilizes a combination of an open ended card cage and a passive backplane with a double-sided staggered array of connectors that allows for the horizontal placement of a large number of computer circuit boards in a low profile design as well as allowing easy access to the circuit boards for repair and replacement The open ended cage design also affords adequate cooling of the circuit components in the confines of a portable case. By hinging the card cage to the portable case, increased accessibility to the circuit boards is afforded. A welding data acquisition and control system embodiment is described that utilizes the portable computer for the acquisition of welding data for use in either operator or automated welding control. The system is capable of utilizing a wide range of welding programs for a wide rang of welding processes.

Abstract: A method of forming or reforming a composite material comprises relatively rotating a pair of members (2,3) while urging them together under pressure so as to mix or remix together the materials (1) making up the composite. The urging direction is substantially parallel with the axis of relative rotation. The composite is then extruded (7).

Abstract: A method of joining a covering layer (9) onto a substrate (10) comprises placing part of the covering layer (9) on the substrate (10) with the remaining part of the covering layer spaced from the substrate so as to expose a region of contact (5) between the covering layer and substrate. A focussed power beam such as a laser or electron beam impinges on the contact region (5) so as to bond or fuse the substrate (10) and covering layer (9) together. The spaced part of the covering layer (9) is then moved towards the substrate (10) so as to change the position of the contact region (5) and the focussed power beam is caused to impinge on the new contact region. These steps are repeated until the covering layer is bonded or fused to the substrate.

Abstract: An electron beam welding system having improved deep penetration weld characteristics in which the electron beam is repeatedly deflected from an undeflected nominal position, as the beam traverses along a weld zone, to build up a heat distribution pattern in the vicinity of the weld zone. The heat distribution pattern is made up of a number of substantially distinct zones of different heat density with a preferred pattern comprising three zones with a space between the first and second zones. The third zone leads the second zone and the space trails the second zone in the direction of traversal of the beam with the maximum heat density occurring in the second zone.

Abstract: A method of bonding an electrical conductor to a contact of an integrated circuit (IC) device comprises bonding the conductor to a support member and to a contact of the IC device. The conductor is then severed to release the IC device and conductor from the support. This allows the IC device to be tested while connected to the support member and provides it with a conductor lead for connection to a carrier for use.

Abstract: A method of providing a material, typically a metal, surface on a substrate (1), comprises applying a consumable member (4) to the substrate (1) under pressure. The member (4) and substrate (1) are moved relative to one another along an arcuate path. Heat is generated at the interface between the member and the substrate so that material is laid down on the substrate along the path. The movement of the metal member (4) typically includes one or more cyclic components.

Abstract: A method of bonding a thermoplastic layer (22), such as APC-2, to a substrate (21) in which the thermoplastic layer (22) comprises electrical conductors such as carbon fibres, embedded in thermoplastic material such as PEEK. The method comprises placing the thermoplastic layer (22) in contact with the substrate (21); and inducing electric currents in the conductors whereby heat generated by the currents passing through the conductors causes thermoplastic material to bond the layer to the substrate.

Abstract: A method and apparatus for causing a beam of charged particles (4) to impinge on a surface of a workpiece (1,1A) along an impingement path (2) such as a weld joint line is described. The apparatus comprises an electron beam source (3); a first control assembly (24) for guiding the beam along the joint line (2) and for deflecting the beam at successive positions onto the joint line; and a second control assembly (22) into which the beam (4) is launched for deflecting the beam at selected positions into the first control assembly. In an embodiment, X-rays are generated and detected to monitor the condition of the weld.

Abstract: A method and apparatus for friction welding a pair of workpieces (45,46) is described. The apparatus comprises a drive assembly (30) for causing relative motion between the workpieces while urging the workpieces together. A load control assembly (20) is provided which is responsive, at least towards the end of a weld cycle, to the rate of motion of one workpiece relative to the other to cause the workpieces to be urged together under a force which increases as the rate of relative motion decreases.

Abstract: The invention provides a gas-shielded arc welding system using two side-by-side electrodes each of which is provided with current pulses superimposed on a respective background current level to maintain the desired controlled spray transfer mode of the weld metal without overheating effects. The pulses are supplied to the two arcs out of phase with one another to minimize interaction of their magnetic fields, but this alone is not sufficient to assure stability of the two arcs. In the system of the invention, one arc is designated as the master arc and the other as the slave arc. The master arc is stabilized by means of a feedback loop controlling its master pulse frequency. Each master pulse triggers a respective slave pulse after a preset time delay, in this way keeping corresponding master and slave pulses in synchronism.

Abstract: A charged particle collector assembly, particularly for use with an electron beam gun, is described. The assembly comprises a reflection member onto which electrons impinge in use, the reflection member being adapted substantially to absorb particles of one polarity and substantially to reflect particles of the other polarity. A sensor or collector is positioned to receive particles reflected from the reflection member and to generate a corresponding output signal.

Abstract: A charge particle beam generator is described which comprises an annular arrangement of filaments (6) which, when heated, emit electrons. A microprocessor controller (not shown) causes a voltage to be applied across each filament (6) in succession so as to cause the filament to generate electrons. An annular anode (9) is provided radially inwardly of the filaments (6) to accelerated electrons away from the filaments in the form of a beam towards a joint between a pair of workpieces to be welded.

Abstract: A welding monitor for use with a welding system is described. The monitor comprises a store (74) for storing at least two sets of predetermined acceptable ranges for one or more welding parameters such as voltage and current. A comparator bank (66,67) is provided for each parameter to compare the operating value of each parameter in use with the corresponding stored range or ranges. A display including sets of light emitting diodes (18-20) displays information relating to the stored ranges and operating values and is responsive to the comparator banks (66,67) to indicate the relationship between an operating value of at least one of the parameters and the corresponding predetermined range.

Abstract: A method of pulsed arc welding and an apparatus for carrying out the method, employ welding current pulses having an amplitude greater than the value of a background current. The arc voltage is sensed to provide a signal for controlling the frequency of the welding current pulses to counteract variations in electrode wire feed speed or spacing of the electrode from the workpiece.

Abstract: Shielded arc welding apparatus advances a consumable electrode towards a workpiece; applies a welding voltage between the electrode and the workpiece; and applies an auxiliary voltage between the electrode and the workpiece, whereby the auxiliary voltage initiates an arc between the electrode and the workpiece before the electrode engages the workpiece.

Abstract: A chuck assembly (8) is described comprising a plurality of external jaws (103) arranged in an annular configuration; and a corresponding plurality of internal jaws (122) positioned within a pipe (13) in use with the internal and external jaws in alignment. The jaws (103,122) are radially movable towards each other to grip the pipe wall therebetween. Each jaw (103,122) includes a gripping portion comprising a recess (128) or projection (127) respectively which cooperate to assist the gripping of the pipe wall by the chuck assembly (8).Examples of the use of these chuck assemblies in friction welding apparatus and pipeline construction apparatus are described.

Abstract: A method of monitoring a structure comprising the steps of:(a) transmitting a burst of acoustic energy through the structure from a transducer coupled to it,(b) detecting a received wave resulting from the burst at one or more transducers coupled to the structure, and(c) monitoring for any change in the structure after a given time (or event) by repeating the steps (a) and (b) with the coupling of the transducers being essentially unaltered, to detect a further received wave or waves; comparing the further received wave or waves with a corresponding reference received wave or waves; and determining for each comparison whether the received wave differs from the reference, any difference being indicative of the formation or growth of a defect in the overall acoustic path travelled by the acoustic energy.