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 conductor stringing block adapted to be threaded with a hauling line dropped by helicopter and having a suspension yoke connected at its ends to the opposite sides of the block frame. The yoke includes a threading passage which is normally closed by a latch effective to transmit load forces crosswire of the passage. The upper end of the threading passage is equipped with an outwardly and upwardly inclined extension to receive and feed a helicopter-dispensed hauling line into the passage. Upright extensions projecting downwardly from the lower end of the passage flex to pass a power line running board and guide the hauling line as it drops from the threading passage onto an underlying sheave of the stringing block. The yoke assembly is securable crosswise of the upper end of a conventional stringing block in lieu of the conventional suspension yoke thereby converting the conventional block to use with helicopter threading equipment.

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 grounding accessory for detachable assembly to a bundle conductor stringing block and having an independently supported grounding roller resiliently biased against a respective bundle conductor despite different sag conditions while the bundle conductors are being pulled into position along a power line. The separate rollers are pivotally supported for independent bodily movement about an axis of support means forming part of a U-shaped main bracket which bracket is spring biased in a direction to maintain each roller in pressure contact with an individual bundle conductor.