US Patent 7032797 Punching-depth adjusting device for use with a nailing gun

A punching-depth adjusting device for use with a nailing gun is adapted to cooperate with the conventional connecting device and has a scale sleeve (16), a sleeve (14), and a resilient C-ring (12). The scale sleeve (16) has an outer periphery and multiple cutouts (162) partially defined around the outer periphery. The sleeve (14) movably sleeves around the scale sleeve (16) and has a through hole (144) defined through the sleeve (14). The resilient C-ring (12) clips on the sleeve (14) and selectively engages with the scale sleeve (16) via the through hole (144). Thereby, the sleeve (14) is enabled to be located at different axial positions to arrange for a predetermined length of a nail to protrude from a workpiece.