Variable height adjustable punch assembly having quick release stripper

Abstract

A punch assembly having infinite adjustment of the punch tool and quick release of the stripper plate. A punch assembly has a clutch mechanism that secures the central punch body after a depth adjustment has been made. The clutch includes two ball bearings with an expansion spring separating the two ball bearings. The spring forces the ball bearings outwardly thus engaging the central body of the punch and the inside wall of the outer casing. This arrangement effectively locks the punch from rotation in either direction. A set of locking cams, disposed directly opposite each other and including a surface with which one may apply an inward force and a set of fingers that have a sloped face that forces the ball bearings toward each other are operated to release the central body from its locked position. This results in infinite, rather than incremental, adjustment of the depth of the punch. As a consequence, when the punch tool is sharpened and its length dimension reduced, the height of the punch tool can be readily adjusted to account for the change in the length dimension of the punch tool. A quick release mechanism for a stripper plate assembly includes a locking ring having three arcuate grooves having radially increasing dimension and three locking clips which are circumferentially fixed relative to the locking ring. The locking clips engage the stripper plate. Upon rotation of the locking ring, the locking clips ride in the arcuate grooves which act as camming surfaces and open the locking clips, thereby releasing the stripper plate. As a result, a quick release is effected, with only the stripper plate itself being released. The mechanism otherwise remains assembled for insertion of a new stripper plate.