BOHREINRICHTUNG IN EINER BOHRANLAGE FUER PROFILSTAHLSTAEBE U. DGL.

摘要

A drilling device for drilling holes in structural steel shapes utilizes a control system having a pair of control pistons to set the drill bit at an optimum distance from the workpiece for repeated drilling of holes through material of a given thickness. The control device responds to position switches sensing the positions of the drill-feed cylinder and the control pistons.