Motor-driven bolster plate

In a press including a supporting frame, a bed mounted on the frame, a bolster plate, a first die member carried by the bolster plate, means for mounting the bolster plate on the bed for sliding movement between a work position in the press and a withdrawn load position out of the press, a ram, a second die member carried by the ram, means for mounting the ram on the frame for movement between a raised open position and a lowered closed position, and means for reciprocating the ram between its raised and lowered positions, the press operating to move the ram to its lowered position with the second die member in engagement with the first die member when the bolster plate is positioned at its work position, control means comprising:

• drive means for reciprocating the bolster plate between its work and load positions, said drive means including a motor, a clutch and a brake operatively interconnected;
• first sensing means for determining when the bolster plate is moved to its work position and being adapted to control operation of said clutch and said brake, whereby said first sensing means deenergizes said clutch and sets said brake to terminate movement of said bolster plate when said bolster plate is at its work position;
• second sensing means for determining when the bolster plate is moved to its load position and being adapted to control operation of said clutch and said brake, whereby said second sensing means deenergizes said clutch and sets said brake to terminate movement of said bolster plate when said bolster plate is at its load position;
• locking means for fixing the bolster plate against movement relative to the press and the ram, said locking means being actuated by said first sensing means when the bolster plate reaches its work position;
• first switch means for triggering the ram reciprocating means when said locking means has fixed the bolster plate to the press;
• means responsive to the operation of the ram for disengaging said locking means when the ram returns to its raised position;
• and
• second switch means for initiating withdrawal of the bolster plate from the press and being adapted to control operation of said clutch and said brake, whereby said second switch means releases said brake and engages said clutch to initiate movement of said bolster plate when said locking means is disengaged.

In a press including a supporting frame, a bed mounted on the frame, a bolster plate, a first die member carried by the bolster plate, means for mounting the bolster plate on the bed for sliding movement between a work position in the press and a withdrawn load position out of the press, a ram, a second die member carried by the ram, means for mounting the ram on the frame for movement between a raised open position and a lowered closed position, and means for reciprocating the ram between its raised and lowered positions, the press operating to move the ram to its lowered position with the second die member in engagement with the first die member when the bolster plate is positioned at its work position, a drive assembly for reciprocating the bolster plate between its work and load positions comprising:

• a motor;
• a crank having one end operatively connected to said motor, the other end being rotated circuitous about said one end;
• and
• a connecting member providing a translating connection between bolster plate and said other end of said crank, said translating connection converting radial motion into linear motion to harmonically reciprocate the bolster plate whereby the bolster plate is smoothly accelerated from a stopped position to maximum velocity and smoothly decelerated from maximum velocity to a stopped position.