"Hole-in-one" metal punch drive unit

A combination pilot drill and drive assembly for use with one or more draw punches, comprising:

• a drill unit including a tubular casing and a drill chuck for holding a pilot drill rotatably mounted at one end thereof, said drill chuck including a hex head located inside said dirve casing;
• and
• a drive unit including a tubular large diameter first socket and a relatively smaller diameter second socket slidably engaged therein, said second socket being springloaded so as to be normally urged outwardly toward the open end of said first socket;
• said casing of said drill unit being sized to fit over said first socket of said drive unit, and said hex head of said drill chuck being sized to engage said first socket, whereby said drill unit may be selectively coupled to said drive unit for use of said drill and drive units in combination in a first mode of use as a pilot drill for drilling a pilot hole in a metal panel, and whereby said drill unit may be removed from said drive unit for use of said drive unit alone in a second mode of use to engage by means of one of said sockets a draw punch for punching a hole in a metal panel.