Patent ID: 7320610

Claim:
In combination: a power rail comprising a generally longitudinally extending profile having a pair of transversely confronting sides only one of which is formed with a longitudinally extending and inwardly open coding groove, the sides forming a longitudinally extending and open slot, and a pair of upper longitudinally extending and transversely spaced conductors on the profile sides; and an adapter comprising a body fittable to the rail, a switch shaft extending from the body along an axis and pivotal thereabout relative to the body between a removing position and an installed position, the shaft extending into the slot when the body is fitted to the rail, a pair of radially projecting contacts, and a radially projecting coding stud on the shaft, the shaft being rotatable in a first predetermined orientation of the body relative to the rail into the installed position with the coding stud engaging in the coding groove and the contacts engageable with the conductors, the other side of the profile being shaped so as to engage and prevent rotation of the shaft from the removing position into the installed position when the body is not in the first predetermined orientation relative to the rail.