Abstract: An upstanding post is provided having a follower guidingly mounted thereon for adjustable positioning therealong. A pull lever is pivotally supported at one end from the follower for limited oscillation about a horizontal axis transverse to the lever and the lever is disposed in position generally paralleling the post. The other end of the lever is notched for engagement with successive links of a pull chain and an elongated longitudinally extendable thrust member has one end anchored relative to the follower and the other end engaged with the lever at a point spaced from its axis of oscillation for angularly displacing the lever away from the first end of the thrust member. The follower includes anchor structure disposed in the plane of swinging movement of the lever and spaced horizontally from the latter in the direction opposite to the direction in which the thrust member is operative to displace the lever.