Abstract: An expanding cone for securing to a reel includes an inner funnel shaped core with a wide end at a base attachable to a support shaft and tapering outwardly from the base. An enclosing body around the core having a plurality of windows. A respective blade at the core below each window and movable outwardly through the window to engage the interior of the mandrel upon the enclosing body moving toward the base of the core. A spring normally biasing the enclosing body off the core away from the base of the core. A pawl pivotally supported to the core engaging the collar of the enclosing body for preventing the enclosing body from being urged toward the base of the core by the installed mandrel. A lever movable to lift the pawl off the collar as the mandrel is installed on the enclosing body until the collar is free to be moved toward the base of the core.