Sheet metal follower associated with a press for bending sheet metal

Abstract

A sheet metal follower associated with a press for bending a metal sheet, the follower being of the type comprising a pivot mechanism capable of causing the follower table to tilt, wherein a toothed wheel that is prevented from rotating is connected to a second toothed wheel by a cog belt, wherein the second toothed wheel pivots inside the cog belt, thereby causing the follower table to pivot about the rotary shaft, and wherein the upward and downward movements of the follower table are synchronized with its pivoting movement so that the plane in which the top support face of said table lies always includes the front edge of the matrix of the bending press.

1 / A sheet metal follower associated with a press for bending a metal sheet, comprising a gap frame, a stationary bottom table carrying a horizontal matrix of triangular section having a front edge and a vertically moving top table carrying a bending punch, said sheet metal follower comprising: 
 a vertical base plate guided horizontally along said bottom table of the bending press, and provided with at least one vertical rail;    a sliding support mounted to slide vertically on said at least one vertical rail of the base plate;    a first servo-motor;    a vertical drive mechanism comprising a wormscrew and a nut, the vertical nut co-operating with said first servo-motor and meshing with tapping of the nut fixed to the sliding support;    a follower table having a top support surface, said table being hinged so as to be capable of tilting about a horizontal shaft; and    a pivot mechanism mounted on said sliding support and capable of causing the follower table to tilt synchronously with the vertical movement of the sliding support so that the plane in which the top face of said follower table lies contains the front top edge of the matrix, said pivot mechanism comprising: 
 a second servo-motor;  
 a pivot shaft pivoted by means of said second servo-motor and gearing mounted on the sliding support;  
 a pivot arm having a first end keyed to the pivot shaft and a second end;  
 a rotary shaft mounted on the second end of said pivot arm to rotate freely;  
 at least one first toothed wheel mounted on said pivot shaft in such a manner as to remain stationary while said shaft pivots;  
 at least one second toothed wheel secured to said rotary shaft and co-operating with said first toothed wheel;  
 at least one connection arm secured to said second toothed wheel and to said follower table; and  
 a cog belt ;  
   wherein said first toothed wheel is connected to said second toothed wheel by said cog belt snugly engaging the teeth of the first and second toothed wheels, wherein said second toothed wheel turns, pivoting inside said cog belt under the action of said pivot arm moving said rotary shaft and said second toothed wheel along a circular arc, wherein the pivoting movement of said second toothed wheel secured to said follower table causes said table to pivot about the rotary shaft, and wherein the upward and downward movements of said follower table are synchronized with the pivoting movements thereof such that the plane in which the top support surface of said follower table lies always contains the front edge of the matrix of the bending press.    
     
     
         2 / A sheet metal follower according to  claim 1 , wherein said pivot shaft is supported in two bearings each mounted in a lateral support arm secured to the top portion of one or other of the vertical edges of the sliding support and directed towards the follower table, wherein said pivot shaft carries on either side of said pivot arm one of said first toothed wheels mounted rotate freely relative to the pivot arm, wherein on either side of the front end of said pivot arm situated adjacent to the follower table said rotary shaft is secured to one of said second toothed wheels coplanar with said corresponding first toothed wheel, wherein each second toothed wheel is fixed on a radial connection arm provided at the rear end of said follower table; said follower table further comprising a cog belt to interconnect one of said first toothed wheels and said second toothed wheel that is coplanar with said one of said first toothed wheels.  
     
     
         3 / A sheet metal follower associated with a press for bending a metal sheet comprising a gap frame, a stationary bottom table carrying a horizontal matrix of triangular section and a vertically moving top table carrying a bending punch, said sheet metal follower comprising: 
 a vertical base plate guided horizontally along said bottom table of the bending pres, said plate being provided with at least one vertical rail;    a sliding support mounted to slide vertically on said at least one vertical rail and provided with two vertical edges, each edge having a top portion;    a vertical drive mechanism comprising a wormscrew and a nut, the vertical nut co-operating with a first servo-motor and meshing with tapping of the nut fixed to the sliding support;    a follower table hinged so as to be capable of tilting about a horizontal shaft; and    a pivot mechanism mounted on the sliding support and capable of causing the follower table to tilt synchronously with the vertical movement of the sliding support so that the plane in which the top face of said follower table lies contains the front top edge of the matrix, said mechanism presenting: 
 a pivot shaft pivoted by means of a second servo-motor and gearing mounted on the sliding support;  
 a pivot arm having one end keyed to the pivot shaft and having its other end carrying a rotary shaft mounted to rotate freely;  
 at least one first toothed wheel mounted on the pivot shaft in such a manner as to be capable of remaining stationary while said shaft pivots;  
 at least one second toothed wheel secured to the rotary shaft and co-operating with said first toothed wheel; and  
 at least one connection arm secured to the second toothed wheel and to the follower table;  
   a lateral support arm secured to said top portion of one or other of the vertical edges of the sliding support and directed towards said follower table;    two bearings for supporting said pivot shaft, each bearing being mounted in said lateral support arm;    two first toothed wheels carried by said pivot shaft on either side of said pivot arm and mounted to rotate freely relative to said pivot arm;    two second toothed wheels, each second toothed wheel being coplanar with one of said first toothed wheels, said second toothed wheels being secured to said rotary shaft on either side of the front end of said pivot arm situated adjacent to said follower table;    two radial connection arms provided at the rear end of the follower table on which said second toothed wheels are fixed;    first and second roller chain means passing around respective pairs of said coplanar first and second toothed wheels;    wherein each first toothed wheel is associated with tensioning and repulsion means, where those associated with the first toothed wheel co-operating with the first chain act on the top strand of said chain in a first direction corresponding to the clockwise direction such that the rollers of the first chain means bear against the rear flanks of the teeth of the corresponding first toothed wheel, and where those means associated with the other first toothed wheel co-operating with said second chain act on the bottom strand thereof in a direction corresponding to the counterclockwise direction so that the rollers of the second chain means are pressed against the other flanks of the teeth of the corresponding other first toothed wheel.    
     
     
         4 / A sheet metal follower according to  claim 3 , wherein said tensioning and repulsion means comprise at least one oblong slot formed in the body of each first toothed wheel, at least one bearing peg fixed in a transverse housing of a support arm and having its free end penetrating in said slot, and a compression spring interposed in said slot between an end face thereof and the peg.  
     
     
         5 / A sheet metal follower according to  claim 3 , wherein said tensioning and repulsion means comprise at least one oblong slot formed in each support arm, at least one bearing peg fixed on each first toothed wheel and having its free end penetrating in said slot, and at least one compression spring interposed in said slot between an end face thereof and the peg.  
     
     
         6 / A sheet metal follower according to  claim 4 , wherein said tensioning and repulsion means comprise a plurality of slots formed in each of the first toothed wheels or in each of the support arms, a corresponding plurality of bearing pegs fixed in corresponding housings of each of the support arms or each of the first toothed wheels and having their free ends penetrating into corresponding slots, and a plurality of compression springs each interposed in a corresponding slot between an end face thereof and a peg.  
     
     
         7 / A sheet metal follower according to  claim 6 , wherein said slots and said transverse housings are uniformly distributed around said pivot shaft.  
     
     
         8 / A sheet metal follower according to  claim 1 , wherein said follower table is provided with an extender support removably mounted on the top end of said table.  
     
     
         9 / A sheet metal follower according to  claim 8 , wherein said extender support is generally H-shaped.  
     
     
         10 / A sheet metal follower according to  claim 8 , wherein said extender support comprises a crossbar parallel to the front face of the bending press and two side bars perpendicular to said front face, and wherein said follower table has a transverse recess provided with an intermediate fixing plate on which the crossbar of said extender support is mounted by means of a fixing bolt which passes through a hole in the crossbar, and in the oblong slot of said intermediate plate and is screwed into a nut that presses against the bottom face of said plate.  
     
     
         11 / A sheet metal follower according to  claim 10 , wherein said transverse recess further includes a fixed jaw, two moving jaws sliding on the bottom of the recess and a rear abutment block, and in addition to fixing on said intermediate plate, said crossbar of said extender support is clamped between said fixed jaw and said moving jaws.  
     
     
         12 / A sheet metal follower according to  claim 8 , wherein said top face of said extender support is provided with a ball bearing for supporting the metal sheet to be bent.