Abstract: A post broken off from a cap previously retained in human bony structure, such as a human tooth, is removed from a hole in the tooth within which the post has been retained, as by cement. The removal is effected by a hollow rotary drill having tooth cutters surrounding the post, said drill while rotating being urged into the hole until the cutters have released the post from the surrounding cement. Preferably an adjustable stop is provided within the drill to abut the outer end of the post when the cutters have reached the inner end thereof, to prevent damage to the root structure beyond the inner end of the post. The inner diameter of the drill closely fits the outer diameter of the post so that it acts as a guide for the cutters as they are urged into the hole within which the post is retained.

Abstract: The head portion of a railway car coupler is provided with forwardly projecting horizontal upper and lower shelves. The leading edge of the top shelf is angled upwardly and rearwardly to provide clearance for coupler droop. Additionally, the leading angle of the coupler can be extended upwardly to establish an improved relation between the leading edges of the mating couplers, thereby minimizing the tendency to have one leading edge slipping under the other during a droop condition of the couplers.