Wedge cam d is secured rigidly to upper die 1 which reciprocates vertically along axis x-x. Punch e punches a hole in strip material 4. In upward motion of wedge cam d, sliding member 2 moves to the right and hook a, connected to member 2 , pulls strip 4 to the next position. In downward motion of upper die 1, sliding member 2 returns to its initial position due to the action of spring 3, and hook a, due to its bevel, is raised above strip 4.
$483$SL,HP$