Enlarging tool for hub bores - uses axis parallel rollers forced into inclined position by tapered mandrel

摘要

The tool is for enlarging the bore on the inner ends of gudgeon pin bosses to prevent fissures at the boss ends due to slight deflection of the pin during operation. A shaft (3) is introduced into the bore of the boss (1) of the piston (2). Along this shaft a pressure roller (5) is slidingly fitted in the spacer (4) whose movement is effected by a shoulder (4'). The shaft has a zone(A) which is tapered, enlarging opposite to the thrust movement. Initially the enlarging madrel with spacer and pressure roller are arranged so that the roller inner ends are still not on the tapered part of the mandrel. The piston is then slid over the mandrel.