Adjustable punch assembly with releasable locking

A punch assembly comprising:

• a guide bushing;
• a punch driver received and axially guided by said guide bushing, said punch driver comprising an external splined index portion having a plurality of angularly spaced grooves elongated in an axial direction;
• a punch mounted for travel with said punch driver;
• a spring tube telescopically connected to said guide bushing for axially directed movement relative to said guide bushing;
• a stripper spring for biasing said spring tube in an axially extended direction relative to said guide bushing;
• a punch cap threadably mated with said punch driver for adjusting a combined axial length of said punch cap, said punch driver, and said punch assembly by rotation of said punch cap relative to said punch driver, said punch cap comprising a radially extending passage opposite said splined index portion of said punch driver;
• and
• a releasable locking means for engaging said punch cap and said punch driver to prevent rotation of said punch cap relative to said punch driver when said releasable locking means is in a locked position, said releasable locking means being selectively movable to an unlocked position to permit rotation of said punch cap relative to said punch driver for adjusting said combined axial length, said releasable locking means comprising a radially movable locking element partially received in a selected one of said plurality of grooves and in said passage to simultaneously engage said punch driver and said punch cap when said releasable locking means is in said locked position.