US2092627A

US2092627A - Carbon brush

Info

Publication number: US2092627A
Application number: US18599A
Authority: US
Inventors: Roy L Adams
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1935-04-27
Filing date: 1935-04-27
Publication date: 1937-09-07
Anticipated expiration: 1954-09-07

Description

R. L. ADAMS CARBON Bnusfl' Sept. 7, 1937.

Filed April 27, 1935 w. ;s rm Wmodour mi t f w Patented Sept. 7, 1937 CARBON BBUSH Roy' L. Adams. Schenectady, N. Y., asaiznor to General Electric Company, a corporation of New York v Application Api-ii 27, 1935, serial No. 18,599 i 3Claima.

The present invention relates to a method for ioining copper to carbon and more particularly to carbon brushes for dynamo electric machines and a method for making the same.

One of the objects of the present invention is to provide a low resistance connection between a carbon brush and the flexible conductor usually employed to carry current to or from the brush.

The novel features which are characteristic of my invention are set forth with particularity in the appended claims. The inventlon itself however will best be understood from reference to the following specification when considered in-connection with the accompanying drawing in which Flg. 1 is a view in elevation of a carbon brush embodying the features of my invention, while Fix. 2 is a cross sectional view of a modified form of my invention.

In carrying out my invention I apply a layer of flnely divided copper to a carbon block l. The block and copper are then heated at an elci'ated temperature, for example about 600 C.-to 800 C., but below the melting point of the copper, while pressure is simultaneously ,applied to the copper to force it into the adjacent pores of the carbon and to weld the copper particles into a solid mass 2. During the heating process, any sulphur in the carbon block I ris to the upper surface thereof and forms a compound with a portion of the copper providing thereby an intermediate layer I of copper sulphide. A flexlble connector l may be secured to the welded copper mass 2 in a manner well known in the art.

Instead of applying pulverled copper to the carbon block as hereinbefore indicated, it usually will be found preferable to apply a cupreous material such as pulverized copper sulphide directly to the carbon block and to heat the copper sulphide and carbon block to a temperature of .about 600 to 800' C. while pressure is simultaneously applied to the copper sulphide. An excess of copper sulphide is employed so that theadjacent pores of the carbon block will be fllled or imprenated and a layer of copper sulphide oorrespondinz to layer 8 of Fig. 1 provided on top of the carbon. A copper plate corresponding to the welded copper mass 2 may then be secured to the layer of copper sulphide in any desired manner, for example by brazing, after which a flexible conductor 4 may be secured to 5 the copper plate. The intermediate layer of copper sulphide is secured to the carbon with such great tenacity that if :an attempt is' made to separate'the copper sulphide from the carbon the break will occur in the carbon rather than at the junction of the copper sulphide layer and the carbon.

Instead of applying flnely divided copper or I copper sulphide to the entire upper surface of the carbon block I may provide an opening in the upper surface of a carbon brush 5 and fill it with pulverized copper or copper sulphide 6 into which a flexible conductor 'l may be inserted after which pressure and heat may be applied to the pulverized material as hereinbefore set forth.

While my invention is partlcularly adapted for use in connection with commutator brushes it will be obvious that it is not limited to such use and that it may be employed in connection with carbon contacts and the like or in any device where a particularly strong connection between copper and carbon is desired.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A carbon block provided with a layer of cop-- per sulphide thereon, the pores of said block adjacent said layer being impregnated with said sulphide.

which comprises applying pulverizedl copper sulphide to a carbon block, heating the block and copper sulphide at an elevated temperature, while pressure is simultaneously applied to the copper sulphide.

' BOY L. ADAMS.