Impact test apparatus

Claim 1

IN APPARATUS FOR DETERMINING THE EFFECT OF IMPACT OF A TEST PROJECTILE UPON A TARGET OF TYPE INCLUDING; (A) A GUN OF THE TYPE HAVING A SMOOTH BORED BARREL ALONG WHICH THE TEST PROJECTILE IS IMPELLED UNDER FORCE OF PROPELLANT GASES BEHIND THE PROJECTILE, AND (B) A BARREL EXTENSION HAVING ITS REAR END ABUTTING THE MUZZLE OF SAID BARREL, (C) SAID BARREL EXTENSION HAVING A PLURALITY OF CO-EXTENSIVE ELONGATED GAS RELIEVING SLOTS EXTENDING THROUGH ITS WALL AND LONGITUDINALLY ALIGNED WITH THE AXIS OF THE BARREL EXTENSION AND EQUI-ANGULARLY SPACED ABOUT SAID AXIS, THE IMPROVEMENTS COMPRISING, SAID BARREL EXTENSION HAVING DISPOSED THEREALONG BETWEEN THE FRONT AND REAR ENDS OF THE SLOTS, (D) A LONGITUDINALLY EXTENDING SEQUENTIAL SERIES OF GAS EXPANSION CHAMBERS SURROUNDING THE BARREL EXTENSION AND COMMUNICATING WITH THE BORE THROUGH SAID SLOTS, (E) SAID SERIES OF CHAMBERS HAVING IN COOPERATIVE ASSOCIATION THEREWITH A SERIES OF RESTRICTED SLOT SETS DISPOSED AT A TRANSVERSE STATION LOCATED BETWEEN PAIRS OF ADJACENT CHAMBERS TO RESTRICT FORWARD PROPAGATION OF GAS THROUGH THE SLOTS, SAID RESTRICTED SLOT SETS COMPRISING A RESTRICTED SLOT MEANS DISPOSED IN EACH OF SAID EQUI-ANGULARLY SPACED SLOTS, EACH OF SAID RESTRICTED SLOT MEANS FORMING AN EXTENSION OF THE WALL SEPARATING THE CHAMBERS OF THE ADJACENT PAIR, WHEREBY EMERGENCE OF GASES FROM THE FRONT END OF THE BARREL EXTENSION PRIOR TO EMERGENCE OF THE TEST PROJECTILE IS SUBSTANTIALLY INHIBITED.