Abstract: A fast action disconnect for releasably coupling parts together such as a power line stringing block and a conventional dog nut at the lower end of a power line insulator. The disconnect has a receiving socket for the dog nut insertable through one side of the disconnect and includes a barrier for releasably but positively locking the dog nut assembled to the disconnect. The barrier is movable between a retracted locking position and an extended release position permitting disassembly of a dog nut relative to the main body of the disconnect.

Abstract: A unitary grounding assembly for pivoting attachment astride a bundle conductor stringing block and provided with grounding rollers biased against the underside of the conductors. The legs of a roller supporting bracket are resilient and constructed to twist lengthwise thereof to accommodate differential sag of the conductors and to maintain the rollers in pressurized electrical contact with a respective one of the conductors.

Abstract: A bundle conductor stringing block having provision for threading the same with a conductor hauling line as the line is dispensed from an aircraft. For this purpose one side frame of the block is provided with a rotary gate having a slot to receive and transfer the hauling line into the block throat and onto a central sheave. The spring-biased gate is held cocked open by a latch released by entry of the hauling line into the slot whereby the gate rotates to its line discharge position. The block includes guard members positioned in the plane of the throat until pivoted to a position clear of the throat by entry of the conductor running board. To minimize the bending moment on the sheave shaft, the axis of the threading gate is located inwardly of a vertical plane through the exterior face of the underlying outer sheave of the block.