Lay-in duct having side-bracing and wire-retaining means

Claim 1

A LAY-IN DUCT FOR RECEIVING ELECTRICAL WIRES, SAID LAYIN DUCT COMPRISING AN ELONGATED CHANNEL-SHAPED DUCT HAVING A BOTTOM WALL AND A PAIR OF OPPOSED GENERALLY PARALLEL SIDE WALLS, AND AN ELONGATED SIDE-BRACING AND WIRE-RETAINING MEMBER EXTENDING TRANSVERSELY OF SAID DUCT AND DISPOSED OPPOSITE SIDE BOTTOM WALL ADJACENT FREE END PORTIONS OF SAID SIDE WALLS, EACH OF SAID SIDE WALLS BEING PROVIDED ON AN OUTER SURFACE THEREOF WITH AN INDENTATION OPPOSITE AN INDENTATION ON AN OUTER SURFACE OF THE OTHER OF SAID SIDE WALLS, EACH OF A PAIR OF OPPOSITE END PORTIONS OF SAID MEMBER BEING PROVIDED WITH AN OUTER LEG PORTION ENGAGING AN OUTER SURFACE OF A RESPECTIVE ONE OF SAID SIDE WALLS AND AN INNER LEG PORTION ENGAGING AN INNER SURFACE OF THE RESPECTIVE ONE OF SAID SIDE WALLS, EACHOF SAID OUTER LEG PORTIONS BEING PROVIDED WITH AN INWARDLY PROJECTING PORTION RECEIVED IN A RESPECTIVE ONE OF SAID INDENTATIONS, EACH OF SAID SIDE WALLS BEING PROVIDED ON AN OUTER SURFACE THEREOF WITH A SHOULDER DEFINING AN EDGE OF THE INDENTATION THEREIN AND FACING TOWARD SAID BOTTOM WALLS, EACH OF SAID INWARDLY PROJECTING PORTIONS OF SAID OUTER LEG PORTIONS BEING PROVIDED WITH A SHOULDER FACING THE SHOULDER OF THE RESPECTIVE SIDE WALL, AND EACH OF SAID SIDE WALLS BEING PROVIDED ON AN OUTER SURFACE THEREOF WITH A CAMMING SURFACE FORMING AN END OF THE INDENTATION THEREIN IN A DIRECTION LONGITUDINALLY OF SAID DUCT, WHEREB Y SAID MEMBER MAY BE REMOVED FROM SAID DUCT BY FIRST MOVING THE MEMBER LONGITUDINALLY OF SAID DUCT TO FORCE SAID INWARDLY PROJECTING PORTIONS RESPECTIVELY OUT OF SAID INDENTATIONS BY MEANS OF SAID CAMMING SURFACES AND THEN PULLING SAID MEMBER OFF SAID DUCT IN A DIRECTION GENERALLY PERPENDICULAR TO SAID BOTTOM WALL.