Press-actuation system

Abstract

A press has upper and lower dies, an actuating element spaced vertically from one of the dies, and a platen carrying the one die and between the element and the one die. A membrane defines a closed chamber having one side operatively bearing vertically on the platen and an opposite side bearing vertically on the element. A fluid supply pressurizes the chamber and maintains in the chamber a predetermined pressure. An actuator connected to the element vertically displaces the element, platen, and one die.

1 . A press comprising: 
 upper and lower dies;    an actuating element spaced vertically from one of the dies;    a platen carrying the one die and between the element and the one die;    a membrane defining a closed chamber having one side operatively bearing vertically on the platen and an opposite side bearing vertically on the element;    supply means for pressurizing the chamber and maintaining in the chamber a predetermined pressure; and    drive means including an actuator connected to the element for vertically displacing the element, platen, and one die.    
   
   
       2 . The press defined in  claim 1  wherein the platen and element together form a compartment holding the membrane.  
   
   
       3 . The press defined in  claim 2  wherein the platen is provided with guide bars in which the element is vertically slidable.  
   
   
       4 . The press defined in  claim 2  wherein the platen is formed with a cavity open toward the element and holding the membrane.  
   
   
       5 . The press defined in  claim 1  wherein the supply means pressurizes the chamber with a gas.  
   
   
       6 . The press defined in  claim 5  wherein the membrane forms a bladder.  
   
   
       7 . The press defined in  claim 1 , further comprising: 
 a source of fluid under pressure;    a valve between the source and the chamber; and    control means connected to the valve and including a sensor connected to the chamber for determining a pressure therein for operating the valve according to a sensed pressure for maintaining the predetermined pressure in the chamber.    
   
   
       8 . The press defined in  claim 7  wherein the valve includes a pressure-reducing valve.  
   
   
       9 . The press defined in  claim 7  wherein the valve includes a proportional valve.  
   
   
       10 . The press defined in  claim 1  wherein the chamber is subdivided into a plurality of individually controllable compartments.  
   
   
       11 . The press defined in  claim 1 , further comprising 
 a second actuating element spaced vertically from the other of the dies;    a second platen carrying the other die and between the second element and the other die; and    a second membrane defining a closed chamber having one side operatively bearing vertically on the second platen and an opposite side bearing vertically on the second element, the supply means also pressurizing the second membrane.    
   
   
       12 . The press defined in  claim 1  wherein the supply means maintains in the chamber a substantially constant pressure regardless of a vertical position of the one die and element.