Spring, spring core and method for producing the same

Abstract

A spring for a spring core, wherein the spring has helical windings and a first end winding and a second end winding, wherein at least the first end winding has a free end and the free end has at least one passage and the opening of the passage is directed outwardly with respect to the end winding of the spring, is distinguished by the fact that the passage is inclined out of a horizontal plane preferably about an angle α in the compression direction of the spring.

What is claimed is: 
     
         1 . A spring core ( 1 ,  10 ) comprising at least two springs ( 2 ,  20 ) and at least two connecting springs ( 3 ), with which the at least two springs ( 2 ,  20 ) are connected, wherein the springs ( 2 ,  20 ) comprise spiral windings and a first end winding ( 201 ,  2001 ) and a second end winding ( 202 ,  2002 ), wherein at least the first end winding ( 201 ,  2001 ) has a free end ( 203 ,  2003 ) and the free end ( 203 ,  2003 ) has at least one passage ( 204 ,  2004 ) and an opening of the passage ( 204 ,  2004 ) is directed to the outside with respect to the end winding ( 201 ,  2001  or  202 ,  2002 ) of the spring ( 2 ,  20 ), wherein the passage ( 204 ,  2004 ) is inclined from a horizontal plane by an angle α in the compression direction of the spring ( 2 ,  20 ), wherein the angle α is 5° to 25°. 
     
     
         2 . The spring core ( 1 ,  10 ) according to  claim 1 , wherein the angle α is 10° to 15°. 
     
     
         3 . The spring core ( 1 ,  10 ) according to  claim 1 , wherein the passage ( 204 ,  2004 ) is V-shaped or U-shaped. 
     
     
         4 . The spring core ( 1 ,  10 ) according to  claim 1 , wherein the passage ( 204 ,  2004 ) is arranged in such a way in the free end ( 203 ,  2003 ) of the first end winding ( 201 ,  2001 ) or the second end winding ( 202 ) that an offset ( 213 ) is obtained between an apex ( 214 ) of the passage ( 204 ) and a central plane X-Y of the spring ( 2 ,  20 ) in the arrangement direction of the central axis of a connecting spring ( 3 ). 
     
     
         5 . The spring core ( 1 ,  10 ) according to  claim 1 , wherein the free end ( 203 ,  2003 ) has a curvature. 
     
     
         6 . The spring core ( 1 ,  10 ) according to  claim 1 , wherein the curvature of the free end ( 203 ,  2003 ) is smaller than the curvature of the remaining resilient windings of the spring ( 2 ,  20 ). 
     
     
         7 . The spring core ( 1 ,  10 ) according to  claim 1 , wherein the free end ( 203 ,  2003 ) in the assembled state of the spring core ( 1 ,  10 ) touches the inner diameter of the connecting spring ( 3 ) with a two-point contact or a three-point contact. 
     
     
         8 . The spring core ( 1 ,  10 ) according to  claim 1 , wherein that the last winding ( 209 ) before the end winding ( 201 ,  2001  or  202 ) has a section ( 210 ) in which the diameter of the last winding ( 209 ) increases continuously. 
     
     
         9 . The spring core ( 1 ,  10 ) according to  claim 1 , wherein the increase in the diameter for this section ( 210 ) is preferably in a range of 5% to 30%, particularly preferably from 15% to 20%, based on the diameter of the remaining resilient windings of the spring. 
     
     
         10 . (canceled) 
     
     
         11 . The spring core ( 1 ,  10 ) according to  claim 1 , wherein the orientation of the springs ( 2 ,  20 ) alternates per row or column, so that two adjacent springs ( 2 ,  20 ) are each connected in pairs with their free end ( 203 ,  2003 ) or with their indentation ( 205 ,  2005 ) of the first end winding ( 201 ,  2001 ) or the second end winding ( 202 ,  2002 ) by a connecting spring ( 3 ). 
     
     
         12 . The spring core ( 1 ,  10 ) according to  claim 1 , wherein the respective last spring ( 2 ,  20 ) of a row or a column of the spring core ( 1 ,  10 ) is oriented in such a way that it is arranged relative to the adjacent spring ( 2 ,  20 ) rotated by about 180° about its vertical axis. 
     
     
         13 . A method for producing a spring core ( 1 ,  10 ) according to  claim 1 , characterized by the following method steps:
 a) providing a spring steel wire;   b) producing the resilient windings and the first end winding ( 201 ,  2001 ) and the second end winding ( 202 ,  2002 ) of the spring ( 2 ,  20 ), and in each case the last resilient winding ( 209 ) before the first end winding ( 201 ,  2001 ) and the second end winding ( 202 ,  2002 ) with the respectively defined section ( 210 );   c) producing at least one bend, in particular a V-shaped or U-shaped passage ( 204 ,  2004 ) and/or the indentation ( 205 ,  2005 ) in the first end winding ( 201 ,  2001 ) of the spring ( 2 ,  20 );   d) connecting two respective springs ( 2 ,  20 ) at their respective first end winding ( 201 ,  2001 ) and at their respective second end winding ( 202 ,  2002 ) with a connecting spring ( 3 ) to form a spring core ( 1 ,  10 ).   
     
     
         14 . The method for producing a spring core ( 1 ,  10 ) according to  claim 13 , wherein after the method step c) the following method step takes place:
 producing at least one bend, in particular the V-shaped or U-shaped passage ( 204 ,  2004 ) and/or the indentation ( 205 ,  2005 ) in the second end winding ( 202 ,  2002 ) of the spring ( 2 ,  20 ).