Device and method for sequentially cold working and reaming a hole

Abstract

A device and a method are provided to allow a user to ream a hole to an accurate final diameter as desired, and at the same time, to cold work the hole to induce a beneficial residual stress that will enhance the life of the component by retarding the onset and growth of fatigue cracks in the hole. The basic design of the device has an elongated body having a forward end portion to extend through a hole to be reamed and cold worked, a reamer section formed on the circumference of the forward end portion to enlarge the hole, and a burnishing section formed on the circumference of the elongated body adjacent to the reamer. The burnishing section is operative to upset the material around the hole, so as to result in a residual stress beneficial to the hole. The reamer section is in the form of a plurality of cutting edges extending from a tip of the elongated body, while the burnishing section is also in the form of a plurality of cutting edges adjacent to the reamer section along the elongate body. The cutting edges of the reamer sections are parallel straight cutting edges or helical cutting edges. The cutting edges of the burnishing section are configured with an orientation opposite to that of the cutting edges of the reaming section. Therefore, when the cutting edges of the burnishing section are configured with the same profile as the cutting edges of the reamer section, the burnishing section is in the form of a backward reamer section.

Dependencies are inferred from the claim text.