Abstract: An electric discharge device has a conductive shell mounted in a non-conductive tube. A non-conductive collar can mount in the conductive shell. The collar includes an annular neck and an annular flange. The neck is encircled by a central annular groove located between a spaced pair of circumferential plateaus. The plateaus are radially dimensioned to fit in the conductive shell. The annular flange is coaxially affixed to and radially larger than the annular neck.

Abstract: An improved portable apparatus for moving and precisely placing a large and heavy object includes load support rails, aligned pairs of anchoring structures secured to and spaced longitudinally from one another along the rails, an actuator-supporting shoe movable along the support rails having lugs for releasably engaging one pair of the anchoring structures to hold the shoe in a stationary position, and an actuator extending between and connecting the shoe with the load movably supported on the rails. The improvements relate to the configuration of the shoe and to a pair of reinforced spaced anchoring pins which allow engagement with one or the other pin by the lugs on the shoe by merely reversing, or rotating 180.degree., the position of the shoe on the rails. In one position of the shoe with its lugs engaged with one of the pins, retraction of the actuator will produce movement of the load in one direction.

Abstract: A transportable heavy-lift apparatus for moving heavy objects comprising a base housing having a plurality of cylinder members vertically supported therein, the cylinder members having a load platform attached to their top ends, and a fluid actuating system disposed in the base housing for vertically moving the cylinder members and load platform. The cylinder members are so arranged such that their common lift vector is substantially aligned with the center of the base housing, and the base housing is constructed such that load forces experienced when moving heavy objects is equally distributed throughout the base housing to its floor plate. Swivel lugs disposed in the top end portions of the cylinder members connect the load platform thereto. The fluid actuating system permits the cylinder members to be independently rapidly elevated to a lift position for an object.

Abstract: The specification discloses an improved system for projecting and utilizing a light beam as a reference line for construction purposes. The system includes a light beam projection device mounted in a housing. A light path compensator is positioned within the housing and intercepts the beam of light emitted by the light beam projecting device and automatically corrects slight deviations of the light beam from true horizontal. A vertically adjustable leg is attached to the front end of the housing and a horizontally pivotable leg is attached to each side of the housing near the rear end of the housing to enable leveling and centering of the housing in a conduit or positioning and leveling on any surface. Structure is controllable from the rear of the housing to deflect the light beam in a vertical plane to vary the grade of the beam projected by the device. An indicator, readable from the rear of the housing, is provided for indicating the grade at which the light beam is projected.