Snap-on Technologies, Inc.

S.s. White Technologies, Inc.

Glenn A Rupp

A flexible shaft having at least one end formed to have a helical square shape, wherein successive cross-sections have square shapes progressively rotated with respect to each other. The overall rotation from where the square cross-section begins to the adjacent end of the shaft is preferably in the range of 10 to 20 degrees. The helical square end is preferably shaped by swaging utilizing helical square dies preferably made by electron discharge machining. When the helical square end of the flexible shaft is forced into a mating square opening of an end fitting, the helical square configuration of the shaft end causes it to be deformed and bind tightly in the fitting with an interference fit, thus reducing vibration and noise when the shaft is rotated. Instead of a helical square shape, the end of the flexible shaft may alternatively have another helical polygonal shape.

Flexible shaft with helical square end

A medullary rotational reaming apparatus includes an elongated, flexible, hollow, tubular shaft formed of a nickel-titanium alloy and having coupling portions at the opposite ends thereof. Each of a cutter head and a rotational drive coupling element has a hollow tubular coupling shank, each shank having a coupling inner surface which is quadrilobular in transverse cross section and is dimensioned to prevent free reception of a coupling portion of the shaft therein. The coupling portions of the shaft are axially press-fitted in permanent engagement, respectively, within the shanks of the cutter head and the drive coupling element, with said coupling portions being permanently deformed to the transverse cross section of the coupling inner surface of the shanks, thereby to fix the cutter head and the coupling element to the shaft solely by the press-fitted engagement of the coupling portions in the shanks.

Growing community of inventors

Highland Lakes, NJ, United States of America

Glenn A Rupp