US1102119A - Brush-holder for dynamo-electric machinery. - Google Patents

Description

A. AICHELE.

BRUSH HOLDER FOR DYNAMO ELECTRIC MACHINERY.

APPLICATION FILED MAY 4, 1912.

1,102,11 9; Patented June 30,1914.

M J/%% a UNITED STATES PATENT OFFICE.

ALBERT .AICHELE, OF BADEN, SWITZERLAND, ASSIGNOR T0 AKTIENGESELLSCHAFT BROWN, BOVERI & CIE., OF BADEN, SWITZERLAND.

BRUSH-HOLDER FOR DYNAMO-ELECTRIC MACHINERY.

To all whom it may concern:

Be it known that I, ALBERT AIoHELn, director, a citizen of the Swiss Republic, of Baden, Switzerland, have invented certain new and useful Improvements in and Relating to Brush-Holders for Dynamo-Electric Machinery, of which the following is a specification.

. This invention relates to brush holders for electrical machines.

Heretofore efforts have been directed to give carbon brushes for electrical machines as firm and as long a support as possible to enable them to maintain their position relatively to the commutator. This principle leads to long and comparatively heavy carbons. and brush holders, and owing to expansions due to heat or to other reasons seizing is liable to occur. Moreover the commutator must be perfectly round and be exactly centered if the good contact of the carbons with long supports is to be maintained.

The object of the present invention is to provide an improved brush holder efficient in action and free of the disadvantages asto weight and otherwise referred to above.

The invention consists in a brush holder in which the carbon or like brush as well as being free to follow irregularity in the commutator surface is also free for a certain distance to move at right angles along this surface.

The invention also consists in a brush holder in which a carbon or like brush is embraced by anarrow frame loosely fitting the carbon, a spring connection being pro vided to permit motion in the direction of the commutator but normally to maintain the brush in its mid position.

Referring to the accompanying drawings which illustrate one manner of carrying the invention into effect: Figure 1 .shows an elevation, andFig. 2 a plan of one construction of brush holding mechanism. Fig. 3 shows certain of the parts illustrated in Fig. 1 with the spring cooperating with the brush in its inoperative position and also (in dotted lines) in the position which it occupies when the brush is worn down. Fig. 4: shows a perspective view of a brush fitted with a modified form of spring.

LThe'form of the invention illustrated includes a brush holder the terminal piece a of which is mounted on' the brush rod (not Specification of Letters Patent.

Patented June 30, 1914..

Application filed May 4, 1912. Serial No. 695,169.

pulled downward by means of a. spiral spring 7. The lever 6 does not bear directly onthe 'brush d but through the medium of a sprlng rod or wire 9 hinged at one end to the lever 0 while its other en'dis attached to a plate It pressing on the brush and supported thereon,

The spring rod g can obviously be replaced by several such members while instead of it one or more plate springs, spiral springs, 01' others may beused so long as they are arranged to restore the brush to its normal position whenit is displaced therefrom.

The spring may also be directly attached to the carbon, so that the plate It is eliminated. I

In the modification shown in Fig. 4 the brush a is provided with'a flat plate spring 5 which is adapted to be pivotally connected to the lever 6 shown in Figs. 13. In this form the plate spring is secured directly to the brush a thereby eliminating the plate It, though the latter may be retained if desired.

The particular construction shown in the drawings are given by way of example and modifications in' the details may be made as desired.

It will be noted'that the main feature of the invention is the spring piece 9 which same to the normal position, while in a radial direction it is practically inelastic and allows the spring f to exert its full pressure. Thus the brush is under the action of at least two springs one of which exerts as usual contact pressure in a direction normal to the commutator while the other operates n a plane at right angles thereto. There 1s thus obtained a similar effect as if instead of carbon, an elastic material had been used. Further, this spring can be so formed that it counteracts an uneven wearing of thebrush. If the wear be not uniform the spring rod causes the pressure to become higher on the less worn edge, while at the most worn edge the pressure diminishes. An inclined position of the carbon which apart from the spring 9 is possible owing to the narrowness of the frame, can not therefore take place and the'axis of the carbon brush always remains radial since the action of the springs opposes any other position. On the other hand the carbon is able'exactly to follow any worn place and eccentricity of the commutator, always remaining in contact with the surface of the same since its mass may be kept small owing to the narrow and light guiding frame.

Having now described my invention what I claim as new and desire to secure by Letters Patent is 1. In dynamo electric machinery in combination a brush means loosely encircling the brush, a lever, a spring connecting said lever and said means together with a member connecting the lever and the brush rigid in the direction of contact pressure but flexible in the direction at right angles thereto; as set forth.

2. In dynamo electric machinery in combination a brush a bracket, an element rigidly attached to said bracket and loosely encircling the brush, a lever pivoted to the bracket, a spring member connecting the lever and the brush rigid in the direction of contact pressure but flexible in the direction at right angles thereto and a spiral spring connecting a pointbetween the pivot and said end of said lever with said encircling means as set forth.

3. In dynamo electric machinery in combination a brush means loosely encircling the brush, a lever, a spring connecting said lever and said means together with a spring wire connecting the lever and the brush rigid in the direction of contact pressure but flexible in the direction at right angles thereto; as set forth.

5. In dynamo electric machinery in combination a brush, means loosely encirclin the brush, a lever and a spring rod inserted between the lever and the brush substantially coinciding with the axis of said brush; as set forth.

5. In dynamo electric machinery in com? bination a brush, a narrow frame encircling said brush with slight clearance on all sides, a spring tending to force the brush in one direction and a further spring tending to force the brush in a direction at right angles thereto on displacement, said further spring being substantially rigid in the direction of pressure "of the first spring; as set forth.

6. In dynamo electric machinery in com bination a brush, a bracket,'an element rigidly attached to said bracket and encircling said brush onall sides with a slight and substantially uniform clearance, a lever pivoted to the bracket, a spiral spring connecting said lever to said bracket and a spring connecting said lever to said brush; as set forth.

In testimon whereof, I afiix my signature in presence 0 two witnesses.

ALBERT AICHELE.

Witnesses CARL GUBLER, AUGUST Rinses.

Images