Abstract: A shaft attachment assembly for fastening a member to a shaft. The shaft has a receptacle end which includes an axial opening therein. A stud is provided for engagement with the receptacle end and has a body portion and a head portion. One of the stud and the receptacle end has surfaces forming a tapered cam surface terminating in a locking detent and the other of the stud and receptacle end has a transverse pin extending laterally therefrom. The member to be fastened to the shaft has an axial passageway therethrough positioned so that when the member is aligned with the receptacle end of the shaft, the passageway and the member will be aligned with the opening of the shaft. The body portion of the stud is extendable through the passageway and the member and the opening in the shaft to bring the pin into rotatable engagement with the cam surface.

Abstract: Device for assembling a first sectional bar onto a second sectional bar, comprising a tubular element positioned within the end of a hollow core of the first bar and having an elongated head portion adapted to be inserted into a groove of the second bar and locked within the said groove by means of a set screw threaded into a hole of said tubular element, said screw extending through an elongated opening of one face of the core of the first bar, whereby said element and said head portion may be fully retracted inside of said core of said first bar.

Abstract: A current limiting circuit breaker having for each pole, a pair of main contacts separable upon operation of a thermally and electromagnetically operable tripping device and a pair of auxiliary contacts for current limiting in series with the main contacts and in parallel with a transformable resistor having a positive temperature coefficient of resistance. The auxiliary contacts are separable when an electromagnet is energized by a fault current which simultaneously energizes a field magnet to produce a transverse magnetic field across the auxiliary contacts and the arc formed between them when separating. This simultaneous action of electromagnet and field magnet coacting for rapid contact separation and lengthening of the arc upon flow of a fault current serves to increase arc voltage almost instantaneously to that of the source, about which time the fault current is totally shunted into the resistor. One of the main contacts of each pole is carried by a movable contact blade.