Patent ID: 6988388
Filing Date: 2006-01-24
Classification: B21H

Abstract:
1. In a thread rolling attachment adapted to be mounted on a machine tool and be selectively moved in an axial direction relative to a workpiece having a cylindrical surface upon which a thread is to be rolled, said attachment having a spring housing, a sun gear rotatably mounted on said spring housing, three planetary gears engaging said sun gear at equidistant locations thereabout, and a helical spring acting between said spring housing and said sun gear, the improvement comprising: a center plate having three circularly-spaced detents; a front plate having a central portion arranged in axially-spaced relation to said center plate and having three circularly-spaced lugs extending toward said center plate such that the distal end surfaces of said lugs are adapted to engage said center plate; a recess extending into each lug from said distal surface, each recess adapted to receive a respective one of said detents for angularly orienting said center and front plates relative to one another; three eccentric roll pins having their opposite marginal end portions journalled on said center and front plates, and spaced equally from one another about an imaginary circle; a thread roll rotatably mounted on each eccentric roll pin; and a plurality of fasteners operatively arranged to selectively hold said center and front plates together; whereby, when said thread rolling attachment is assembled, said front plate will have improved rigidity and will be less susceptible to deformation.