Workpiece blanking apparatus

A workpiece blanking apparatus comprising:

• a die;
• a pad for holding a plate of metal on said die;
• a blanking punch for depressing the plate on said die downwardly of the die to blank a workpiece out of the plate;
• a counterpunch vertically movably disposed in said die in confronting relationship to said blanking punch and movable downwardly with the workpiece blanked by said blanking punch;
• counterpunch urging means for normally urging said counterpunch upwardly;
• and
• holding means for holding said counterpunch in a lowered position after the workpiece is blanked by said blanking punch until said blanking punch is spaced from the workpiece, said pad is spaced from the plate, and said blanking punch and said pad are lifted to a predetermined position, and for releasing said counterpunch in said lowered position and allowing said counterpunch to displace said workpiece out of said die when said blanking punch and said pad are lifted to said predetermined position, wherein said holding means comprises:
• a pusher vertically movably disposed below said die for transmitting a biasing force from said counterpunch urging means to said counterpunch;
• a cam tiltably disposed between said pusher and said die, for preventing said pusher from ascending upon angular movement into an erected position and allowing said pusher to ascend upon angular movement into a tilted position;
• and
• cam driving means for angularly moving said cam into the erected position when said pusher is lowered in response to downward movement of said counterpunch depressed by said blanking punch, and for angularly moving said cam into the tilted position when said blanking punch and said pad are lifted to said predetermined position.

A workpiece blanking apparatus comprising:

• a die for supporting a plate of metal thereon;
• a blanking punch for depressing the plate downwardly of said die to blank a workpiece out of the plate;
• a counter punch vertically movably disposed in said die in confronting relationship to said blanking punch and movable downwardly with the workpiece blanked by said blanking punch;
• a pusher vertically movably disposed below said counter punch, said pusher providing a force directing said counter punch toward said blanking punch;
• and
• a blocking device engaging said pusher and movable between a first position and a second position, said blocking device permitting said pusher to move said counter punch toward said blanking punch when said blocking device is in said first position thereby permitting said counter punch to displace the blanked workpiece out of said die, and said blocking device preventing said pusher from moving said counter punch toward said blanking punch when said blocking device is in said second position thereby preventing said counter punch from displacing the blanked workpiece out of said die at a lowered position
• wherein said blocking device comprises a slider disposed for movement in a horizontal direction along an upper surface of said pusher,
• wherein said blocking device has a cam projecting from a lower surface thereof, and said pusher has a follower located on said upper surface thereof which is engagable with said cam of said blocking device, and
• wherein said follower comprises:
• a horizontal upper surface for engaging said cam when said cam is out of engagement with said follower and said slider is in said first position;
• a first slanted surface inclined continuously obliquely downwardly from said horizontal upper surface, for guiding said cam to slide from said horizontal upper surface;
• a horizontal lower surface contiguous to said first slanted surface for allowing said cam to slide horizontally thereon and said slider is in said second position;
• and
• a second slated surface inclined continuously obliquely upwardly from said horizontal lower surface in confronting relationship to said first slanted surface at a progressively increasing angle, for limiting sliding movement of said cam from said horizontal lower surface.

A workpiece blanking apparatus comprising:

• a die for supporting a plate of metal thereon;
• a blanking punch for depressing the plate downwardly of said die to blank a workpiece out of the plate;
• a counter punch vertically movably disposed in said die in confronting relationship to said blanking punch and movable downwardly with the workpiece blanked by said blanking punch;
• a pusher vertically movably disposed below said counter punch, said pusher providing a force directing said counter punch toward said blanking punch;
• and
• a blocking device engaging said pusher and movable between a first position and a second position, said blocking device permitting said pusher to move said counter punch toward said blanking punch when said blocking device is in first position thereby permitting said counter punch to displace the blanked workpiece out of said die, and said blocking device preventing said pusher from moving said counter punch toward said blanking punch when said blocking device is in said second position thereby preventing said counter punch from displacing the blanked workpiece out of said die at a lowered position,
• wherein said blocking device comprises a slider disposed for movement in a horizontal direction spaced above an upper surface of said pusher.