Abstract: Apparatus is disclosed for transporting heavy equipment such as welding current generators, a prime mover therefor, and associated devices or supplies, on and along a pipeline, the pipeline serving as a monorail. The apparatus, of elongated construction along the pipeline, is supported at one end and propelled along the line by power driven traction means engaging the top part of the pipeline. The opposite end of the apparatus is supported on a pair of laterally spaced swivel mounted wheels which engage the sides of the pipeline laterally away from and somewhat below the top of the line. The latter wheels give lateral support and stability to maintain the apparatus in a substantially upright position on the pipeline. Sensing means, such as a pendulum, mercury switch means, or equivalent, detect incipient tilting or motion towards instability and are used to steer the swivel mounted wheels, either directly or indirectly.

Abstract: Signals which contain components that vary with the lateral position of an electric welding instrument as it travels along a weld path between opposite work pieces are obtained from the arc or other heat source and are first processed to remove confusing or nonsignificant components. The processed signals are then compared or combined with each other, or with other signals of predetermined value, to obtain outputs which can be used to determine or control the lateral position or movement of the welding instrument along the weld path. Specifically, in electric arc welding of metals, signals from an electrical characteristic at the arc, such as arc current, which include a component indicative of lateral position of the welding instrument with respect to one or more sidewalls, are first filtered and processed to remove undesirable components.

Abstract: A pipe bending mandrel having a housing assembly of a plurality of interconnected, axially aligned segmented housing subassemblies, each of which has an internal taper, a plurality of spherical members spaced along a tension member and adapted to coact with the internal housing tapers, a plurality of axially extending flexible strips connected to the housing segments, and an actuator connected to the spherical members and the housings to move the spherical members into the internal housing tapers to expand the housings into pipe supporting position within a pipe to be bent. Suitable wheels are provided for moving the mandrel into, through and out of the pipe.

Abstract: A self-propelled arc welding device, which uses an inert gas within a primary zone to protect superheated metal from contact with atmospheric elements, is shielded with an outer compartment to protect against external air currents in the form of a portable shroud which closes off air currents along the work surface, at least partially. Particularly, for protecting girth welds in pipelines welded by a track-guided machine moving orbitally about the pipe, the compartment includes elements which make a substantially line contact with the pipe surface. The carriage which supports the welding device preferably carries the arc-enclosing shield. An observation window or opening for watching the arc is provided and free access to controls and adjustment means is permitted so that normal control operations are not hampered.

Abstract: Apparatus and method for welding girth joints in pipelines and similar structures, of the general type described and claimed in U.S. Pat. No. 3,806,694, is improved by adding to the normal or conventional head, on its frame, a second or supplemental welding head with its own independent wire electrode, electric power and shielding gas supply. The second head is mounted on an adjustable support for accommodating work pieces of different radius or for varying arc positions. Oscillating means for spreading the molten metal across the width of the joint, as normally provided for the single welding head in the patent mentioned, are adapted to operate the second head as well and to vary its amplitude of movement. Separate means are provided for adjusting the spacing between each head and the work and also for lateral adjustment to align the heads with the plane of the joint. By these means, the number of stations required for a multiple pass operation, on thick wall pipe, for example, may be reduced.