Compression coil spring device having discontinuous support structure

Abstract

In a compression coil spring device, suitable for use in a strut wheel suspension system, including a coil wire wound into a coil having an end turn, the end turn is adapted to be supported by a spring seat at one or a plurality of discrete points. This can be accomplished either by providing a plurality of projections on the coil wire along the length of the coil wire of the end turn or by providing a plurality of projections for supporting the end turn at one or a plurality of discrete points of the spring seat. Thus, the spring demonstrates a same property with regard to the centroid of contact pressure or line of action of the spring force, and the spring constant without regard to the spring load as long as the spring end is supported by the same discrete contact point or points. In other words, the changes in the number of effective turns depending on the magnitude of the load can be minimized so that the relationship between the load and compression stroke can be made substantially linear, and the change in the angle of the axis of the spring force can be minimized. Also, in the above structure, the end turn contacts the spring seat only at the predetermined projections, and this minimizes the variation in the spring property, frictional resistance between the contacting members and bending moment relating to individual coil springs.

1 . A compression coil spring device including a coil wire wound into a coil having an end turn, wherein: 
 said end turn is adapted to be supported by a spring seat at one or a plurality of discrete points.    
   
   
       2 . A compression coil spring device according to  claim 1 , wherein said coil wire is provided with a plurality of projections arranged along the length of the coil wire of said end turn.  
   
   
       3 . A compression coil spring device according to  claim 2 , wherein said projections are defined by wavy parts of said coil wire.  
   
   
       4 . A compression coil spring device according to  claim 2 , wherein said projections are defined by enlarged parts of said coil wire.  
   
   
       5 . A compression coil spring device according to  claim 2 , wherein said projections are defined by annular members fitted on said coil wire.  
   
   
       6 . A compression coil spring device according to  claim 2 , wherein said projections are defined by projections formed on a tubular member which is fitted on said coil wire.  
   
   
       7 . A compression coil spring device according to  claim 1 , further comprises a spring seat which is provided with a plurality of projections for supporting said end turn at one or a plurality of discrete points.