Method of making a carbon commutator

Abstract

A method of making a carbon commutator is provided. The method includes the steps of providing a planar substrate having a series of current-carrying regions; providing a carbon base having a brush-contacting surface and a second opposite surface; substantially covering the second surface of the carbon base with a conductive plating to form an unslotted commutator body; applying a conductive bonding layer to the conductive plating; bonding the unslotted commutator body to the substrate; and cutting corresponding slots in the commutator body to form a series of commutator segments.

What is claimed is: 
     
       1. A method of making . .the.!. .Iadd.a .Iaddend.commutator comprising the steps of: providing a planar substrate having a series of current-carrying regions;   providing a carbon base having a brush-contacting surface and a second opposite surface;   substantially covering the second surface of the carbon base with a conductive plating to form an unslotted commutator body;   applying a conductive bonding layer to said conductive plating;   bonding the unslotted commutator body to the substrate; and   cutting corresponding slots in the commutator body to form a series of commutator segments.   
     
     
       2. The method of claim 1 wherein said step of providing a carbon base comprises molding fine-grain electrical grade carbon into a shape having at least two opposite surfaces. 
     
     
       3. The method of claim 1 wherein said first substantially covering step comprises plating the second surface of the carbon base with a first conductive material selected from a group consisting of nickel, copper, gold, silver, or alloys thereof to form a first conductive layer. 
     
     
       4. The method of claim 3 wherein said substantially covering step further comprises plating the first conductive layer with a material selected from a group consisting of copper, gold, silver, cadmium, chromium, or alloys thereof. 
     
     
       5. The method of claim 1 wherein said substantially covering step comprises the steps of plating the second surface of the carbon base with a first conductive material to form a first conductive layer and plating the first conductive layer with a second conductive material which is the same as the first conductive material. 
     
     
       6. The method of claim 1 wherein said first substantially covering step comprises the steps of plating the second surface of the carbon base with a first conductive material to form a first conductive layer and plating the first conductive layer with a second conductive material which is different than the first conductive material. 
     
     
       7. The method of claim 1 wherein said applying and said bonding steps comprise the steps of depositing an electrically conductive adhesive on the second conductive layer and adhesively fastening the unslotted commutator body to the substrate. 
     
     
       8. The method of claim 1 wherein said applying and bonding steps comprise the steps of depositing a low-melting conductive bonding material on the second conductive layer, placing the second conductive layer adjacent the substrate, and placing the unslotted commutator and the substrate in a heat-bonding environment. .Iadd. 
     
     
       9.  A method of making a commutator having a plurality of commutator sections with substantially coplanar brush contacting surfaces, comprising: providing a substrate having a substantially planar and conductive surface and a series of current carrying regions;   providing a carbon base having a substantially planar brush-contacting surface and a second substantially planar surface that is opposite from said first surface;   bonding said second surface to the conductive surface of said substrate; and   cutting slots in said carbon base to subdivide said base into a series of carbon base segments so that each carbon base segment defines a brush-contacting surface formed from said first surface, and each carbon base segment together with an associated current carrying region defines one of said commutator sections..Iaddend..Iadd.10. The method of claim 9, wherein said carbon base is toroidal in shape..Iaddend..Iadd.11. The method of claim 9, wherein said carbon base is formed from electrical grade carbon..Iaddend..Iadd.12. The method of claim 9, wherein said second surface is adhesively bonded to the conductive surface or said substrate   
     
     
        to provide an electromechanical bond..Iaddend..Iadd.13.  A method of making a commutator comprising the steps of: providing a preformed substrate having at least one substantially planar face with a conductive plate affixed thereto and conductive tangs extending from said conductive plate;   providing a preformed carbon base having a brush-contacting surface and a second opposite surface;   bonding said second opposite surface to said conductive plate;   bonding said carbon base to said substrate; and   cutting slots in said carbon base to subdivide said base into a series of carbon base segments so that each of said carbon base segment is isolated electrically from the other carbon base segments..Iaddend..Iadd.14. The method of claim 13 wherein each of said carbon base segments is electrically connected through said conductive plate to one of said tangs..Iaddend..Iadd.15. The method of claim 13 wherein said conductive plate has a thickness of about 0.15 mm to about 0.75 mm..Iaddend..Iadd.16. The method of claim 13 wherein wherein said conductive plate has a thickness of about 0.30 mm to about 0.60 mm..Iaddend..Iadd.17. The method of claim 13 wherein the step of providing a pre-formed carbon base comprises molding fine-grain electrical grade carbon..Iaddend.