Sheet holder for perforation press and method for moving sheet holder

Abstract

The present invention relates to a perforating press for perforating sheet material comprising a feeding means for feeding sheet material in a first direction; at least one punch holder, wherein the punch holder extends in a second direction transverse to the first direction, and wherein the punch holder comprises at least one punch; a die, wherein the die comprises openings for receiving punches of the punch holder a transmission shaft for linear displacement of the punch holder in a stroke direction transverse to the first and second directions; and a discharge means for discharging perforated sheet material; wherein the perforating press comprises a sheet holder, wherein the sheet holder is positioned between the punch holder and the die according to the stroke direction, wherein the sheet holder is movable according to the stroke direction by the transmission shaft, and wherein the sheet holder comprises cut-outs for passage of punches of the punch holder. The invention also relates to a method and a use.

1 . Perforating press for perforating sheet material comprising a feeding means for feeding sheet material in a first direction; a punch holder, wherein the punch holder extends in a second direction transverse to the first direction, and wherein the punch holder comprises at least one punch; a die, wherein the die comprises openings for receiving punches of the punch holder; a transmission shaft for converting a rotary movement of the transmission shaft into a linear movement of the punch holder in a stroke direction transverse to the first direction and transverse to the second direction and a discharge means for discharging perforated sheet material; characterized in that the perforating press comprises a sheet holder, wherein the sheet holder is positioned between the punch holder and the die according to the stroke direction, wherein the sheet holder is movable according to the stroke direction by the transmission shaft, and wherein the sheet holder comprises cut-outs for passage of punches of the punch holder. 
     
     
         2 . Perforating press according to  claim 1 , characterized in that a distance over which the sheet holder is movable by the transmission shaft according to the stroke direction is at most 60% of a distance over which the punch holder is movable by the transmission shaft according to the stroke direction. 
     
     
         3 . Perforating press according to  claim 1  or  2 , characterized in that the sheet holder and the punch holder have a fixed position relative to each other according to the first direction and the second direction. 
     
     
         4 . Perforating press according to any of the previous  claims 1 - 3 , characterized in that the punch holder is movable by the transmission shaft according to the stroke direction according to a linear path between a first extreme point and a second extreme point, and that the sheet holder is movable by the transmission shaft according to the stroke direction according to a linear path between a third extreme point and a fourth extreme point, the first extreme point and the third extreme point being farthest from the die, and wherein a distance according to the stroke direction between the first extreme point and the third extreme point is adjustable. 
     
     
         5 . Perforating press according to  claim 4 , characterized in that there is a rotation of at least 20° and at most 40° of the transmission shaft between the first extreme point and the third extreme point. 
     
     
         6 . Perforating press according to any of the previous  claims 1 - 5 , characterized in that the perforating press comprises a ram element, wherein the ram element is positioned between the transmission shaft and the sheet holder, wherein the ram element is movable by the transmission shaft according to the stroke direction, wherein the perforating press further comprises guide elements for guiding the sheet holder and the ram element according to the stroke direction, and wherein between the sheet holder and the ram element at least one hydraulic cylinder is positioned for preloading the sheet holder in the direction of the die. 
     
     
         7 . Perforating press according to  claim 6 , characterized in that a first port of the at least one hydraulic cylinder is connected to a first side of an accumulator. 
     
     
         8 . Perforating press according to  claim 7 , characterized in that a back pressure on a second side of the accumulator is adjustable. 
     
     
         9 . Perforating press according to one of the preceding  claims 7 - 8 , characterized in that the pressure at the first port of the at least one hydraulic cylinder is adjustable. 
     
     
         10 . Method for moving a sheet holder from a perforating press including:
 feed sheet material according to a first direction;   perforating the sheet material by moving a punch holder in a stroke direction by a transmission shaft, wherein the punch holder extends in a second direction transverse to the first direction, wherein the punch holder comprises at least one punch, wherein the transmission shaft converts a rotary movement of the transmission shaft into a linear displacement of the punch holder in the stroke direction, transverse to the first direction and transverse to the second direction, and wherein the at least one punch is moved through the sheet material into a die, wherein the die comprises openings for receiving punches of the punch holder;   repeat previous steps until a predetermined pattern of perforations is established in the sheet material;   
       characterized in that a sheet holder is moved according to the stroke direction by the transmission shaft, wherein the sheet holder is positioned according to the stroke direction between the punch holder and the die, and wherein the at least one punch of the punch holder is moved through a cut-out in the sheet holder into the die. 
     
     
         11 . Method according to  claim 10 , characterized in that the punch holder is moved by the transmission shaft according to the stroke direction according to a linear path between a first extreme point and a second extreme point, and that the sheet holder is moved by the transmission shaft according to the stroke direction according to a linear path between a third extreme point and a fourth extreme point, the first point and the third point being farthest from the die, and a distance according to the stroke direction between the first extreme point and the third extreme point being set before feeding the sheet material. 
     
     
         12 . Method according to  claim 11 , characterized in that the fourth extreme point is set so that the sheet holder does not touch the sheet material. 
     
     
         13 . Method according to  claim 11 , characterized in that the fourth extreme is set such that the sheet holder presses against the sheet material after the at least one punch of the punch holder perforates the sheet material and the sheet holder continues to press at least against the sheet material until the at least one punch of the punch holder is removed from the sheet material. 
     
     
         14 . Method according to  claim 11 , characterized in that the fourth extreme point is set such that the sheet holder presses against the sheet material before the at least one punch of the punch holder perforates the sheet material and the sheet holder continues to press at least against the sheet material until the at least one punch of the punch holder is removed from the sheet material. 
     
     
         15 . Use of a perforating press according to one of  claims 1 - 9  and/or a method according to one of  claims 10 - 14  for the manufacturing of grilles for household appliances.