US1548466A

US1548466A - Brush for electrical machines

Info

Publication number: US1548466A
Application number: US479599A
Authority: US
Inventors: Hettinger Fred
Original assignee: Chas E Chapin & Co
Current assignee: Chas E Chapin & Co
Priority date: 1921-06-22
Filing date: 1921-06-22
Publication date: 1925-08-04
Anticipated expiration: 1942-08-04

Description

Aug. 4, 1925. 1,548,466

F. HETTINGER BRUSH FOR ELECTRICAL MACHINES Filed June 22, 1921 11v VENTOR /4 ZwL/v 8 ILA? TOkIVEYS Patented Ans". l- TEES.

UNITED STATES PATENT orrics.

FEED HETTINGER, OF RUTHERFORD, NEW (TIER-E3131", ASSIG-NOB, TO CHAS. E. CI-IAPIN n 60., A CORPORATION OF NEW YORK.

BRUSH, FQB, ELECTRICAL MACHINES.

Application filed June 22, 1921. Serial No. erases.

T 0 all to 710m it may concern Be it known that I, Finn) Hnrrnvenn, a citizen of the United States, residing at Rutherford, N. J, have invented certain new and useful improvements in Brushes] for Electrical Machines, of which the following is a clear, full, and exact description.

This invention relates to brushes for use in dynamos, motors and other electrical machines and to processes of making the same.

In one of the most common forms of brushes for electrical machines, the brushes are made of wire gauze folded and compressed into the desired shape to form a brush. In order to hold the commutator engaging ends of the wires of brushes of this character in place and prevent them from digging into or scratching the commutator, a lubricating metal, such as lead, is commonly applied to the brush in a molten condition and allowed to harden upon the same. Brushes of this type heretofore produced have had the lubricating metal applied to the brush so as to leave certain interstices in the body of the brush and often there are certain parts of the gauze of which the brush is composed contacting with the commuta tor, which are not covered with the lubricating metal. Thus, in the prior brush constructions, the lubricating material is not always effective in preventing the scratchingof the commutator and particles of the wires of the gauze are often dislodged by the engagement of the commutator with the brush, and enter the bearings of the commutator shaft, thereby causing a great deal of trouble. This latter difliculty has induced the use of solid metal brushes to a considerable extent, although such brushes are far more expensive than wire gauze brushes and in certain respects do not give as good results. in addition to the application of lubricating metal, such as lead, to the gauze, the end of the brush is often dipped in solder to hold the brush together.

Une object ofthe present invention is to produce a brush of thewire gauze type in which a lubricating metal is applied to the wires in a novel and improved manner, so as to prevent more effectively the digging of the wires into the commutator and the dis lodgement of small particles of wires from the brush and also so as to hold the brush together in a reliable manner. l/Vith this ob ject in view, a feature of the present invention consists in a brush having a lubricating metal applied to the wires so as to fill entirely the interstices between the same and form in connection with the wires a solid block. ,The application of the lubricating metal to the wires in this manner increases the effectiveness of the metal in holding the wires in place at the point at which they engage the commutator 'and also enables the lubricating metal to lubricate more thoroughly the point of contact of the brush with the commutator.

Another feature of the present invention consists in a brush, the body of which is formed of wire gauze and which has a solid or unbroken metallic layer on the exterior thereof, the surface of which is smooth and even, and which consists chiefly at least of the metal of which the wire gauze is formed. With a brush having a solid metallic layer of this character, there is practically no liability that small particles of the brush will become dislodged therefrom when the brush is in use, and the exterior of the brush will have substantially the same char acter and appearance as that of a solid metal brush made of the metal of which the gauze is formed.

Certain other features of the invention relate to the method employed in forming the solid exterior surface of the brush.

The invention also involves certain other novel and improved features hereinafter described and particularly pointed out in the claims, the advantages of which will be read ily understood and appreciated by those skilled in the art.

The invention will be readily understood from the accompanying drawings illustrating a brush embodying the invention in its preferred form and also illustrating certain steps in the process which is preferably followed in making the brush, taken in connection with the following detailed description of the brush and the process of making the same In the drawings, Fig. 1 is a perspective view of a strip of wire gauze wound into a flattened roll preparatory to forming a brush therefrom Fig. 2 is a perspective view of the roll of gauze after compression into the desired shape to form a brush g nseaeee Fig. 3 is a perspective view illustrating the manner in which the lubricating metal is applied to the brushes;

Fig. l is a perspective view of a brush a tier the lubricating metal has been applied thereto;

Fig. 5 is a perspective view illustrating the manner in which the exterior oi? the brush is finished after the application of the lubricating metal to the brush; and

Fig. 6 is a perspective view of a completed brush.

In making a brush in accordance with the present invention as preferably carried out, relatively narrow strip of wire screen or gauze made of copper, brass or other metallic wire and preferably cut on the bias, is wound into a roll such as that indicated at 2, Fig. 1, which may be either cylindrical in term or may be somewhat flattened, as shown in said figure, depending upon the shape which the brush is to have after compression. The roll of gauze is then subjected to a heavy pressure to compress the same into the desired brush form. Fig. 2 of the drawing illustrates the roll after compression to form a brush, indicated at t, of prismatic shape.

After the roll of gauze has been compressed into the desired shape, the lubricating or anti-friction metal is applied to the compressed block thus termed in such a manner to coat all of the surfaces ot the wires and to form in connection with said wires a solid block. The lubricating metal may be advantageously applied to the brush by immersing the brush in a bath ol this metal in a molten condition. In order to clean the surfaces of the wires of which the block is made and to provide a suitable flux for the lubricating metal, the block is first dipped or soaked in a suitable soldering solution. The block is then taken from the soldering solution and deposited in a bath consisting of the lubricating metal. Preterably the lubricating metal em )loyed is relatively soft as con'ipared with the metal cl which the wires of the brush are termed and should such as to have a relatively high degree of electrical conductivity and to give the proper lubricating cti cct. Pure lead has been found in practice to give highly satieitactory results although other metals or alloys having the proper qualities may be used in a molten condition. The block is soaked in this bath of molten metal long enough to allow the metal to penetrate all the interstices in the block and to cover the surfaces of all of the wires of which the block is formed. As illustrated in Fig. 3, the brushes l are immersed in a tank 6 containing a bath of the lubricating metal indicated at 8 in a molten condition. After having been soaked for asur'licient length oi time in the metal bath, the block is removed from the bath and allowed to cool so that the lubricating metal hardens and forms in connection with the wires ot the block, a solid metallic block, all of the lubricating metal being allowed to be retained within the body of the block. Fig. 4; shows one of the brushes after it has been removed from the bath at the lubricating metal and the metal has been allowed to harden thereon, the brush being indicated by the reference numeral 9.

illrtter the application. of the lubricating metal to the brush, the brush is preferably formed with a substantially solid metallic layer on the outside thereof, the outer surface at which is smooth and even, said layer consisting principally at least of the metal of which the wires of the brush are formed. The brush may be easily and cheaply pro vided with such a metallic layer by subjecting the exterior of the brush after the ap plication of the lubricating metal thereto to the-action of a polishingor abrading device. Fig. 5 of the drawings illustrates a series of? the blocks resting on a table 10 and being subjected to the action of a grinding or abrading wheel 12. During the abrading operation the metal of which the wires of the brush are composed is swaged and spread. over the exterior surface 01? the brush, thereby giving the brush a solid metallic exterior layer having a smooth even surface and composed almost entirely of this metal. When the brush is made of copper wire gauze, for example, the brush. alter the abrading operation will have substantially the appearance of a solid copper brush. Fig. 6 sh( vs a brush after the exterior thereof has been subjected to the action of an abrading device to form a layer of metal of the character described on the exterior of the brush, the brush being indicated by reference numeral 14-.

Brushes may be made in accordance with the present process with very little, if any, addition to the cost oil. manufacture as compared with an ordinary brush of the wire gauze ype and may be made much more cheaply than a solid metallic brush. On account of the manner in which the lulu'icating material is applied to and retained in the lillld'l, there is no necessity of dipping the brush in a soldering solutioi'i to hold the same together.

It is to be understood that the invention is not limited to the particular brush con struction or to the particular process of making the same illustrated and des ribed in the present application, but that the invention may be embodied in brushes ot di'l'titerent constructions and that the process may be varied from that described within the scope of the claims.

Having explained the nature and object of the invention and having specifically described a form in which the invention is preferably applied, what is claimed is:

1. A brush for electrical machines, comprising a series of conducting wires, and lubricating metal filling all of the interstices between the wires and forming in connection with said wires a solid block. I

2. A brush for electrical machines comprising a series of layers of wire gauze compressed into block form, and lubricating metal filling the interstices between the wires of the same layer and between the wires of adjacent layers to form a solid block.

A brush for electrical machines, comprising a coil of Wire gauze compressed into block fornnand lubricating metal filling the interstices between the wires of said block and forming in connection with said wires a solid block.

4. A brush for electrical machines, comprising wire gauze formed into a block and lubricating metal entirely filling the interstices between the wires of said block to form a solid block.

5. A brush for electrical machines comprising a section of wire gauze folded and compressed into a block and a lubricating metal filling the interstices between the wires of said block, said block having a smooth surfaced substantially solid metallic exterior layer principally composed of the metal of which said wires are formed.

6. A brush for electrical machines, comprising a section of wire gauze folded and compressed into a block the body of which is provided with a smooth surfaced substantially solid metallic exterior layer.

7. A brush for electrical machines comprising a section of wire gauze folded and compressed into a block and having a smooth surfaced substantially solid metallic exterior layer composed chiefly of the metal of which said wires are formed.

8. A brush for electrical machines comprising a section of wire gauze folded and compressed into block form and having the wires on the exterior thereof flattened and smoothed oil and the points between said wires filled in with metal composed chiefly at least of the. material of which said wires are formed to form a substantially smooth exterior surface.

9. A brush for electrical machines comprising a section of wire gauze made into block form and having the wires on the exterior thereof flattened and smoothed ofl and the points between said wires filled in with metal composed chiefly at least of the material of which said wires are formed to form a substantially smooth exterior surface.

10. A brush for electrical machines, the body of which is formed of wire gauze and having its outer part abraded to form a smooth surfaced substantially solid metallic exterior composed principally of the metal of which the wire gauze is formed.

11. The process of making a brush for electrical machines, which comprises folding a strip of wire gauze and compressing the same to form a block, treating the block with a soldering solution, soaking the block in a bath of pure molten lead and then abrading the exterior of the block to give the same a smooth exterior surface.

12. The process of making a) brush for electrical machines, which comprises folding a strip of wire gauze and compressing the same to form a block, and abrading the exterior of the block to give the same a smooth exterior surface.

13. A process of making a brush for elec trical machines which comprises as a step, abrading the exterior of a wire screen block so as to form a smooth surfaced, substantially solid exterior layer composed principally of the metal of which the screen is formed.

lt. A process 'of making a brush for electrical machines which includes as a step, applying a lubricating material to a wire screen block so as to fill entirely the interstices between the wires of the screen and form in connection with said wires a solid block.

15. A brush for electrical machines comprising a wire gauze foundation and lubrieating metal entirely filling the interstices between the wires of said gauze to form a solid metallic block.

16. A brush for electrical machines comprising a series of 'rouped wires arranged in brush form and compressed into a block and having its outer part abraded. to form a smooth surfaced substantially solid metal lic exterior layer.

Signed at Rutherford, N. J. this 17th day of June, 1921.

MR. FRED I-lETTlNGEl-t. l/Vitnesses M. GIRHER, FRANK B. MOREHEAD.