Die-side ejector device for workpieces in single-stage or multi-stage presses

Abstract

In a die-side ejector device for presses, a stationary press die cooperates with a press ram on a press frame in order to shape a blank introduced into a bore of the press die. An ejector pin is displaceably provided in a bore in the press frame, said ejector pin being biased against an ejector lever which is pivotable by an actuator lever between a starting position and a final ejection position and which is supported, on its side facing away from the ejector pin in its starting position, on a pressure piece on the press frame. The ejector lever is pivotably arranged on a carrier part, which is displaceable on the press frame, perpendicular to the longitudinal axis of the ejector pin and in parallel with the plane of pivot of the actuator lever, between two stops and is provided, in order to contact the pressure piece, with a shaped surface which may be brought into areal contact with a complementary shaped surface on the pressure piece, wherein both shaped surfaces maintain their areal, complementary contact in the starting position of the ejector pin even upon displacement of the carrier part.

1 . A die-side ejector device for workpieces in single-stage or multi-stage presses, wherein a stationary press die is provided on a press frame, said press die cooperating with a press ram for shaping a blank introduced into a bore of the press die, said device comprising an ejector pin slidably supported within a bore in the press frame, the die-side end of said ejector pin protruding into the bore of the press die and the other end thereof being biased against an ejector lever which is in turn pivotable, via an actuator lever driven by a cam gear, between a starting position, in which the die-side end of the ejector pin is retracted into the bore of the die, and a final ejection position, said ejector lever having its side facing away from the ejector pin in its starting position supported on a pressure piece mounted on the press frame, wherein the ejector lever is pivotably arranged on a carrier part, which is displaceable on the press frame, in a direction perpendicular to the longitudinal axis of the ejector pin and in parallel with the plane of pivot of the actuator lever, between two stops and which is provided, on its side facing the pressure piece, with a shaped surface for contact therewith, said shaped surface being designed for areal contact with a complementary shaped surface on the pressure piece, wherein both shaped surfaces maintain their areal, complementary contact in the starting position of the ejector lever even when the carrier part is being displaced.  
     
     
         2 . The ejector device as claimed in  claim 1 , wherein the shaped surface is provided with a convex curvature on the ejector lever and the complementary, concave shaped surface is provided on an otherwise cylindrical pressure piece.  
     
     
         3 . The ejector device as claimed in  claim 2 , wherein the pressure piece is pivotable about a central axis on a pressure plate mounted on the press frame.  
     
     
         4 . The ejector device as claimed in  claim 1 , wherein the carrier part for the ejector lever is a displaceable supporting pusher or supporting carriage.  
     
     
         5 . The ejector device as claimed in  claim 1 , wherein the ejector lever is provided as a two-armed lever, with the ejector pin contacting the end region of one lever arm and a rotatable roll being mounted on the end region of the other lever arm, said roll being supported against the actuator lever, which is provided, relative to the ejector lever, on the same side thereof as the ejector pin.  
     
     
         6 . The ejector device as claimed in  claim 1 , wherein the cam gear for the actuator lever comprises a cam disk mounted on an ejector shaft, on which cam disk there runs a roll rotatably mounted on the free end of the actuator lever, said actuator lever being biased against the cam disk in order to urge the roll against the cam disk.  
     
     
         7 . The ejector device as claimed in  claim 1 , wherein the ejector pin comprises a larger-diameter piston portion mounted in the bore in the press frame and provided as a displaceable piston and a subsequent smaller-diameter portion protruding into the bore of the press die, said portion being guided through a cover plate closing the bore in the press frame on the die side, and that the region between the larger-diameter piston portion and the cover plate of the bore in the press frame is connected to a pressure air supply line in order to bias the ejector pin against the actuator lever.  
     
     
         8 . The ejector device as claimed in  claim 1 , wherein a device for biasing the ejector lever against the actuator lever is provided, said device being independent of the ejector pin.  
     
     
         9 . The ejector device as claimed in  claim 8 , wherein the device for biasing the ejector lever consists of a piston arranged within a further bore in the press frame, said piston being spring-biased against the ejector lever and being supported by a sliding shoe on the side of the actuator lever facing the piston.  
     
     
         10 . A press comprising: 
 a press frame;    a press ram;    a stationary press die provided on the press frame, wherein said press die cooperates with the press ram for shaping a blank introduced into a bore of the press die;    an ejector pin slidably supported within a bore in a press frame, said ejector pin having a die-side end, second end, and a longitudinal axis, the die-side end protruding into the bore of a press die;    an ejector lever, wherein the ejector pin second end is biased against said lever, the lever being pivotable, via an actuator lever, between a starting position, wherein the ejector pin die-side end is retracted into the bore of the press die, and a final ejection position, and wherein the ejector lever presents an opposing face in relation to the ejector pin, said opposing face in the starting position supported on a pressure piece mounted on the press frame;    a carrier part, upon which the the ejector lever is pivotably arranged and having a side facing the pressure piece, said carrier part displaceable on the press frame, in a direction perpendicular to the longitudinal axis of the ejector pin and in parallel with the plane of pivot of the actuator lever, between two stops, said side facing the pressure piece having a shaped surface, said shaped surface designed for areal contact with a complementary shaped surface of the pressure piece, wherein both shaped surfaces maintain their areal, complementary contact in the starting position of the ejector lever when the carrier part is being displaced.    
     
     
         11 . The press as claimed in  claim 10 , wherein the shaped surface is provided with a convex curvature on the ejector lever and the complementary, concave shaped surface is provided on an otherwise cylindrical pressure piece.  
     
     
         12 . The press as claimed in  claim 11 , wherein the pressure piece is pivotable about a central axis on a pressure plate mounted on the press frame.  
     
     
         13 . The press as claimed in  claim 10 , wherein the carrier part for the ejector lever is a displaceable supporting pusher or supporting carriage.  
     
     
         14 . The press as claimed in  claim 10 , wherein the ejector lever is provided as a two-armed lever, with the ejector pin contacting the end region of one lever arm and a rotatable roll being mounted on the end region of the other lever arm, said roll being supported against the actuator lever, which is provided, relative to the ejector lever, on the same side thereof as the ejector pin.  
     
     
         15 . The press as claimed in  claim 10 , wherein the cam gear for the actuator lever comprises a cam disk mounted on an ejector shaft, on which cam disk there runs a roll rotatably mounted on the free end of the actuator lever, said actuator lever being biased against the cam disk in order to urge the roll against the cam disk.  
     
     
         16 . The press as claimed in  claim 10 , wherein the ejector pin comprises a larger-diameter piston portion mounted in the bore in the press frame and provided as a displaceable piston and a subsequent smaller-diameter portion protruding into the bore of the press die, said portion being guided through a cover plate closing the bore in the press frame on the die side, and that the region between the larger-diameter piston portion and the cover plate of the bore in the press frame is connected to a pressure air supply line in order to bias the ejector pin against the actuator lever.  
     
     
         17 . The press as claimed in  claim 10 , wherein a device for biasing the ejector lever against the actuator lever is provided, said device being independent of the ejector pin.  
     
     
         18 . The press as claimed in  claim 17 , wherein the device for biasing the ejector lever consists of a piston arranged within a further bore in the press frame, said piston being spring-biased against the ejector lever and being supported by a sliding shoe on the side of the actuator lever facing the piston.  
     
     
         19 . A die-side ejector device for workpieces in single-stage or multi-stage presses, wherein a stationary press die is provided on a press frame, said press die cooperating with a press ram for shaping a blank introduced into a bore of the press die, said device comprising an ejector pin slidably supported within a bore in the press frame, the die-side end of said ejector pin protruding into the bore of the press die and the other end thereof being biased against an ejector lever which is in turn pivotable, via an actuator lever driven by a cam gear, between a starting position, in which the die-side end of the ejector pin is retracted into the bore of the die, and a final ejection position, said ejector lever having its side facing away from the ejector pin in its starting position supported on a pressure piece mounted on the press frame, characterized in that the ejector lever is pivotably arranged on a carrier part, which is displaceable on the press frame, in a direction perpendicular to the longitudinal axis of the ejector pin and in parallel with the plane of pivot of the actuator lever, between two stops and which is provided, on its side facing the pressure piece, with a shaped surface for contact therewith, said shaped surface being designed for areal contact with a complementary shaped surface on the pressure piece, wherein both shaped surfaces maintain their areal, complementary contact in the starting position of the ejector lever even when the carrier part is being displaced.  
     
     
         20 . The ejector device as claimed in  claim 19 , wherein the ejector lever is provided as a two-armed lever, with the ejector pin contacting the end region of one lever arm and a rotatable roll being mounted on the end region of the other lever arm, said roll being supported against the actuator lever, which is provided, relative to the ejector lever, on the same side thereof as the ejector pin.