Mechanism for controlling form roll movement in spin flow necking machine

Abstract

A method and apparatus for spin flowing necking-in a D&I can is disclosed wherein an externally located free-spinning form roll is moved radially inward and axially against the outside wall of the open end of a trimmed can. A spring loaded interior support slide roll moves under the forming force of the form roll preferably through a cam control surface which controls the forming force acting thereon as the form roll advances radially inward as it slides along a sloped forming surface of a second free roll mounted axially inwardly adjacent the slide roll. To minimize the plug diameter variation between successively necked cans, the radially inward movement of the form roll is halted at a predetermined radial location via contact between the form roll support bracket with a form roll stop bracket. This prevents excessive form roll forces generated during radial inward advancing movement from acting against the second roll in a manner possibly causing undesirable radial movement thereof with correspondingly excessive plug diameter variation or wearing of coating material on interior necked-in can surfaces located between the form roll and the second roll.