Method for producing cutlery and a cutlery blanking tool

Abstract

The present invention is directed to a method of producing cutlery and a blanking tool to be used in said method of producing cutlery. In the method a sheet metal is placed on a die. The sheet metal is held fixed on the die by means of a holder. In a blanking stroke a punch cooperates with the die to form at least a part of a circumference of a cutlery blank in the sheet metal while the holder holds the sheet metal fixed on the die. Thereafter the sheet metal is released from the die. The blanking tool comprises an upper part in the form of a punch, an intermediate part in the form of a holder and a lower part in the form of a die. The blanking tool further comprises means to move the punch and the holder together as one unit towards the die during a first part of a blanking stroke for the punch. The punching tool comprises means to move the punch in relation to the holder during a second part of the blanking stroke for the punch. The holder abuts the sheet metal placed on the die during said second part of the blanking stroke for the punch.

1 . A method of producing cutlery, comprising
 placing sheet metal on a die;   holding the sheet metal fixed on the die by means of a holder;   making at least one blanking stroke by means of a punch cooperating with the die to form at least a part of a circumference of a cutlery blank in the sheet metal while the holder still holds the sheet metal fixed on the die; and   releasing the sheet metal from the die.   
     
     
         2 . The method of  claim 1 , wherein in a first part of the blanking stroke the holder and the punch move together towards the die, wherein in a second part of the blanking stroke the holder contacts the sheet metal and presses the sheet metal against the die while the punch is moved towards the holder and the die to finalize the blanking stroke and wherein the second part of the blanking stroke begins in that the holder contacts the sheet metal. 
     
     
         3 . The method of  claim 1 , wherein the circumference of the cutlery blank is formed in at least two separate blanking strokes, wherein a first part of the circumference is formed by means of a first blanking part in a first blanking stroke, and a second part of the circumference is formed by means of a second blanking part in a second blanking stroke. 
     
     
         4 . The method of  claim 1 , wherein one or more parts are blanked from the area of the sheet metal inside the circumference of the cutlery blank by means of one or more blanking strokes. 
     
     
         5 . The method of  claim 1 , wherein a cutlery blank formed by the at least one blanking stroke and separated from the sheet metal is placed in a deburring die having a die space with rounded inner edges, wherein the cutlery blank is pressed in the die space of the deburring die to obtain rounded edges in at least a portion of that periphery of the cutlery blank which was separated from the sheet metal. 
     
     
         6 . The method of  claim 5 , wherein said step of pressing the cutlery blank in the deburring die is separate from a subsequent step of giving the piece of cutlery its three dimensional form by exposing the cutlery blank to a forming tool and/or to hot forging. 
     
     
         7 . The method of  claim 1 , wherein the punch is provided with at least one blanking part that co-operates with a corresponding opening in the die, wherein a clearance between the at least one blanking part and the opening is in the range of 0.008 to 0.5 mm, and preferably between 0.01 mm and 0.4 mm, and most preferably between 0.01 mm and 0.02 mm. 
     
     
         8 . The method of  claim 1 , wherein the piece of cutlery is a fork, a knife or a spoon. 
     
     
         9 . A cutlery blanking tool adapted for being placed in a press producing cutlery, wherein the blanking tool comprises an upper part in the form of a punch, an intermediate part in the form of a holder and a lower part in the form of a die, wherein the blanking tool comprises means to move the punch and the holder together as one unit towards the die during a first part of a blanking stroke for the punch, and that the blanking tool comprises means to move the punch in relation to the holder during a second part of the blanking stroke for the punch, wherein the holder is adapted for abutting a sheet metal placed on the die during said second part of the blanking stroke for the punch and to hold the sheet metal against the die. 
     
     
         10 . The blanking tool of  claim 9 , wherein the punch has at least one blanking part that protrudes in a direction towards the holder and the die. 
     
     
         11 . The blanking tool of  claim 10 , wherein a first blanking part has the general shape of the piece of cutlery to be produced. 
     
     
         12 . The blanking tool of  claim 11 , wherein at least a second blanking part has the shape of a through opening and/or a notch to be formed in the final piece of cutlery. 
     
     
         13 . The blanking tool of  claim 9 , wherein the punch comprises guiding means received in openings of the holder and the die, which guiding means protrude from the punch in a direction towards the holder and the die. 
     
     
         14 . The blanking tool of  claim 13 , wherein the guiding means of the punch comprises two guiding blocks having a generally rectangular cross section. 
     
     
         15 . The blanking tool of  claim 13 , wherein the guiding means of the punch comprises four guiding pins, each placed adjacent one corner of the punch and protruding in a direction towards the holder and the die. 
     
     
         16 . The blanking tool of  claim 15 , wherein each guiding pin is received in a through opening of the holder and in an opening of the die. 
     
     
         17 . The blanking tool of  claim 8 , wherein springs are placed between the punch and the holder. 
     
     
         18 . The blanking tool of  claim 10 , wherein the holder has one or more openings for receiving the at least one blanking part of the punch during the second part of the stroke of the punch. 
     
     
         19 . The blanking tool of  claim 10 , wherein the die has one or more openings for receiving the at least one blanking of the punch during the second part of the stroke of the punch. 
     
     
         20 . The blanking tool of  claim 19 , wherein the clearance (x) between the one or more openings of the die and the corresponding at least one blanking parts of the punch is below 0.05 mm, and preferably below 0.02 mm.