DE4109187

Apparatus for positioning a rotary member such as a vehicle wheel at a balancing machine in such a way that the rotary member can be lifted into a position, at the level of the balancing machine measuring spindle, in which the longitudinal center lines of the measuring spindle and the rotary member are aligned with each other and the rotary member can be moved concentrically relative to the measuring spindle. The apparatus has two equal-length positioning arms which are pivotally connected at an apex point in a scissor-like arrangement and which are pivotable uniformly relative to each other about their connecting point in a plane which is perpendicular to the measuring spindle. The positioning arms connecting point is displaceable along a line which is perpendicular to the longitudinal center line of the measuring spindle and which coincides with the line bisecting the angle formed by the positioning arms. A support member for supporting the rotary member from below and an abutment member for bearing against the rotary member in its upper portion are mounted to respective ones of the positioning arms at mounting points such that upon displacement of the positioning arms in the opposite direction to the longitudinal center line of the measuring spindle, the mounting points of the support member and the abutment member move along a common straight line towards the longitudinal center line of the measuring spindle.