Bristles having varying stiffness

Abstract

Bristle stiffness is varied by allowing a support beam that carries the bristles to undergo torsional movement in response to brushing action. Torsional movement is achieved by allowing the support beam to be disconnected to the brush head along at least portions of the length of the support beam. In particularly preferred embodiments, brushes employing the varying stiffness techniques are made with bristle sub-assemblies that have at least one row of bristles connected to a base string or similar structure that functions as a support beam. The base string can be connected across an opening in the brush, and is thus connected at its opposite ends, or it can be connected at any number of spaced intervals, the number and length of spacing being selected to achieve a desired degree of stiffness.

What is claimed is:  
     
         1 . A brush comprising: 
 a brush head; and    a bristle sub-assembly having at least one row of bristles connected to a support beam, the support beam, along its length, being at least partially disconnected to the brush head and partially connected to the brush head.    
     
     
         2 . A brush according to  claim 1 , wherein the brush head has at least one outer surface, and the support beam is connected to the outer surface at least at spaced intervals.  
     
     
         3 . A brush according to  claim 1 , wherein the support beam is connected to the outer surface along at least a bond line that is substantially coincident with a line of tangency between the support beam and the outer surface.  
     
     
         4 . A brush according to  claim 1 , wherein the support beam is selected from the group consisting of a base string, a bond line and a glue line.