Brush assembly

Abstract

A brush assembly has a base with a member to secure the base to a motor end cap assembly. A brush housing is associated with the base. The brush housing includes first and second open ends. A brush, defining an axis, is slidably supported within the housing. The brush extends from one of the first and second open ends. The brush includes a surface with a spring retention plunge. The spring retention plunge defines an arcuate face angled relative to the axis. A biasing member exerts a force directly on the arcuate face to bias the brush into contract with a commutator. An electrical connection is made between the commutator and a power supply.

1 . A brush assembly for an electric motor having an end cap assembly and a commutator, comprising: 
 a base having a member for securing said base to the motor end cap assembly;    a brush housing associated with said base and having first and second open ends;    a brush, defining an axis, slidably supported within said housing between said first and second open ends, said brush extending from one of said first and second open ends, said brush including a surface having a spring retention plunge, said spring retention plunge defining an arcuate face angled relative to said axis on an angle greater than 0° and up to 15° and a wall formed in said surface for retaining contact of said biasing member with said spring retention plunge;    a biasing member having a contact end exerting a force directly on said arcuate face for biasing said brush within said housing for contact with the commutator, said contact end defining a line which extends across said arcuate face such that said contact end abuts said arcuate face along said line for prohibiting excessive movement of the contact end along an axis transverse to said brush axis; and    an electrical connector electrically coupled with said brush for electrical connection between the commutator and a power supply.    
   
   
       2 . (canceled)  
   
   
       3 . The brush assembly of  claim 1 , wherein a slope of said spring retention plunge enables transverse retention of said spring.  
   
   
       4 . A brush for an electric motor, comprising: 
 a body having a desired configuration for fitting within a housing, said body defining an axis; and    a spring retention plunge formed in a surface of said body, said plunge defining an arcuate face angled relative to a plane transverse to said axis, said surface at a terminal end of said body, wherein a slope of said arcuate face is greater than zero degrees and up to 15°, said arcuate face having a curvature sized to receive a spring such that the spring contacts the arcuate face along a line to prohibit excess movement of the spring on the arcuate surface for enabling spring force exerted thereon to be substantially constant as said body wears and a wall in said surface for retaining contact of a biasing member with said spring retention plunge.    
   
   
       5 . (canceled)  
   
   
       6 . The brush of  claim 4 , wherein said slope of said spring retention plunge enables transverse retention of a biasing member.  
   
   
       7 . A method of manufacturing a brush for an electric motor, comprising the steps of: 
 providing a brush blank defining an axis therethrough and having a top surface;    forming an arcuate spring retention plunge in said top surface having a slope relative to said axis; and    plunging one of a grinding disc and cutting wheel into said top surface.    
   
   
       8 . (canceled)  
   
   
       9 . The method of  claim 8 , further comprising the step of angling said one of a grinding disc and cutting wheel at an angle relative to said axis.  
   
   
       10 . The method of  claim 7 , further comprising the step of providing a diameter of said arcuate spring retention plunge, perpendicular to said axis, enabling lateral retention of a biasing member.  
   
   
       11 . The method of  claim 7 , further comprising the step of providing a degree of said slope of said spring retention plunge sufficient to enable transverse retention of a biasing member.