Hollow bicycle crank and method for manufacturing same

Abstract

A crank arm for a bicycle includes a crank arm body having a pedal attachment hole on a first end thereof and a spindle attachment hole on a second end thereof. The crank arm body defines an elongated interior cavity, wherein the interior cavity is open to an exterior of the crank arm body. The opening can be used to access the cavity during and after manufacturing. In the method used to form the crank arm body according to the present invention, a sand mold core is positioned into a casting mold so that a melt space is formed around the sand mold core, molten metal is poured into the casting mold, and the molten metal is solidified to form a crank billet. Sand is preferably removed through an opening in the crank billet. This may be accomplished by drilling the crank billet to form the pedal attachment hole in a location that communicates with the sand mold and then removing sand through the pedal attachment hole.

Dependencies are inferred from the claim text.