Method and apparatus for securing a hazardous zone surrounding a moving tool

Abstract

A method and a sensor for the securing of a hazardous zone of a moving tool having a point of attack is disclosed. A monitored zone with a boundary surface is monitored whose cross-section extends along an arc of a circle or beyond it, wherein the center of the arc of a circle is arranged spaced apart from the point of attack of the tool in the direction of movement of the tool, and wherein the arc of a circle has a radius which is at least so large that the boundary surface of the monitored region extends—at least on the operator side—up to the point of attack of the tool or radially beyond the boundary surface.

1 - 29 . (canceled)  
     
     
         30 . A method of securing a hazardous zone ( 17 ) of a moved tool having a point of attack ( 27 ), in particular of a vertically downwardly moving upper tool ( 11 ) of a bending press, 
 wherein an optoelectronic sensor is moved with the tool ( 11 ) and monitors the hazardous zone and wherein, when an intervention into the hazardous zone is detected, a switching off process is triggered for a stopping of the tool movement,    comprising the steps of expanding a transmitted light beam of a transmitter device by means of an optical transmitting system and using a spatially resolving reception device having a matrix-like arrangement of reception elements, such that the optoelectronic sensor monitors a spatial volume ( 29 ).    
     
     
         31 . A method in accordance with  claim 30  wherein the spatially resolving reception device has a CCD or CMOS receiver.  
     
     
         32 . A method in accordance with  claim 30  wherein the spatial volume ( 29 ) is monitored at least along a closed boundary surface ( 31 ) of the spatial volume ( 29 ).  
     
     
         33 . A method in accordance with  claim 32  wherein the spatial volume ( 29 ) is monitored also within said boundary surface ( 31 ).  
     
     
         34 . A method in accordance with  claim 30  wherein the monitored spatial volume ( 29 ) has a boundary surface ( 31 ) which is convexly curved with respect to the point of attack ( 27 ) of the tool ( 11 ).  
     
     
         35 . A method in accordance with  claim 30  wherein the monitored spatial volume ( 29 ) is arranged in the direction of movement ( 15 ) of the tool ( 11 ) with respect to the point of attack ( 27 ) of the tool ( 11 ).  
     
     
         36 . A method in accordance with  claim 30  wherein the monitored spatial volume ( 29 ) has a boundary surface ( 31 ) which extends parallel to the direction of extent of the point of attack ( 27 ) of the tool ( 11 ).  
     
     
         37 . A method in accordance with  claim 30  wherein the monitored spatial volume ( 29 ) has a boundary surface ( 31 ) whose shape is matched to the shape of the tool ( 11 ), to the shape of a workpiece to be worked and/or to a geometrically determined preclusion of an intervention.  
     
     
         38 . A method in accordance with  claim 30  wherein the movement of the tool ( 11 ) is divided into a closing movement ( 15 ) and a subsequent, slower working movement.  
     
     
         39 . A method in accordance with  claim 38  wherein the transition from the closing movement ( 15 ) to the working movement takes place at a time at which the monitored spatial volume ( 29 ) directly adjoins the desired position of a workpiece ( 25 ) to be worked, or adjoins the de-sired position of a workpiece ( 25 ) to be worked at a spacing of less than 10 mm.  
     
     
         40 . A method in accordance with  claim 38  wherein the monitoring of the monitored spatial volume ( 29 ) is deactivated at the time of the transition from the closing movement ( 15 ) to the working movement.  
     
     
         41 . An optoelectronic sensor for the securing of a hazardous zone ( 17 ) of a moved tool having a point of attack ( 27 ), in particular a vertically downwardly moving upper tool ( 11 ) of a bending press; 
 at least comprising one transmitter device for transmitting a transmitted light beam in the direction of the hazardous zone, a reception device for detecting the transmitted light beam, and an evaluation device for triggering a switching off process on the detection of an intervention into the hazardous zone,    wherein the sensor can at least be partly moved with the tool ( 11 ); and    wherein the optoelectronic sensor is adapted to monitor a spatial volume ( 29 ), wherein the sensor comprises an optical transmitting system which expands the transmitted light beam of the transmitter device, and wherein the reception device is made spatially resolving having a matrix-like arrangement of reception elements.    
     
     
         42 . A sensor in accordance with  claim 41  wherein the spatially resolving reception device has a CCD or CMOS receiver.  
     
     
         43 . A sensor in accordance with  claim 41  wherein the optoelectronic sensor is adapted to monitor at least a closed boundary surface ( 31 ) of the spatial volume ( 29 ).  
     
     
         44 . A sensor in accordance with  claim 41  wherein the monitored spatial volume ( 29 ) has a boundary surface ( 31 ) which is convexly curved with respect to the point of attack ( 27 ) of the tool ( 11 ).  
     
     
         45 . A sensor in accordance with  claim 41  wherein the transmitter device has at least one laser diode or LED.