US2956256A - Arc electrode brush mechanism - Google Patents

Description

J) E a w W L SIS-14 FIPSSGZ Oct. 11, 1960 c. SHEER ARC ELECTRODE BRUSH MECHANISM Filed Nov. 19, 1957 INVENTOR CA ma 5 SHEER /Lm,

ATTORNEY ARC ELECTRODE BRUSH MECHANISM Charles Sheer, Teaneck, N.J., assignor to Sheer-Korman Associates, Inc, New York, N.Y., a corporation of Delaware Filed Nov. 19, 1957, Ser. No. 697,408

2 Claims. (Cl. '3399) This invention relates to a brush holder for use where current is fed to an electrode at high current densities, as for example in a hierarc (high erosion are).

With such an arc the high erosion of the anode makes it necessary to feed it forward at a high rate of speed. Moreover, especially where the anode contains salts of a poor conducting material, and the anode itself as a consequence is of a high resistance, it is highly desirable for the brushes to be as near to the anode face as possible. This has, however, presented practical problems since the temperature adjacent to the anode face may reach 10,000 C. or more.

It is important that the current be admitted to the electrode as close to the anode face as possible to avoid resistance losses in the electrode between the brushes and the are. This is particularly important where the anode has a large content of non-conducting or poorly conducting material, such as occurs in certain uses of the hierarc in chemical processes. In some cases, if the brush holder is too far from the anode face the material or form of the electrode may be seriously damaged by undue heating.

It is an object of this invention to provide a brush holder which can in itself assist in preventing undue rise in the temperature of the brush, and in this way the temperature of the electrode itself can be kept at an acceptable value.

This brush holder is suitable for brushes of different cross-sectional shapes, but it is particularly designed for use with a brush of square cross section, since with such a brush a uniform contact pressure may be maintained against an electrode throughout the area of contact. The brush here illustrated is therefore designed to operate with a square electrode.

The invention accordingly comprises the invention herein described and shown in the accompanying drawings in which Figure l is a perspective view of the brush holder with one brush removed, and one spring disassembled to better show the construction. Figure 2 is a perspective view of the brush retainer forming a part of the assembly brush holder, but showing the form of the cooling passage within it. Figure 3 is a section through one of the brush retainers showing its assemblage with the brush.

As here shown, the brush holder comprises bracket 10, to which four brush retainer blocks 11 are attached. Since these brush retainers are all of identical construction it will not be necessary to describe more than one. Each of these retainers as shown comprises a rectangular block, and these blocks are equally spaced around the periphery of the electrode 25. Each block on the side nearest to the electrode has a rectangular recess 12 shaped to receive a rectangular graphite or other carbon brush 13, which preferably fits snugly but slidably within the recess 12 fitting against the opposite faces of the retainer blocks 11. On the opposite side of the retainer there is preferably cut a groove 14 to receive a leaf spring 15. This leaf spring at its rim will bend downwardly as shown at 16, and is screwed to the retainer by a screw 17.

A a w Patented Oct. 11, 1960 An adjusting screw 18 passes through an opening 19 in the outer face of the retainer, and screws into the outer face of the carbon brush 13 as shown at 20. This screw has a head 21 underneath the spring 15, so that the leaf spring forces the carbon brush inwardly toward the axis of the brush holder. A pigtail 22 attached to the carbon brush 13 may be attached to the bracket 10 or to any other stationary part of the brush holder to give the maximum electrical conductivity to the brush.

Because of the very high temperature involved in a hierarc it is desirable to have means for cooling the retainer 11, and this is accomplished by providing a passage way 23 circuitously arranged within the brushholder, and a suitable cooling liquid or fluid is circulated within this passage way to prevent overheating of the retainer. The manner of distributing the cooling fluid within the retainer should be such as to secure the maximum trans for of heat from the brush to the cooling fluid. In Figure 2 there is shown in dotted lines the passage way which has been used, which carries considerable part of the cooling fluid path through that portion of the retainer which embraces the brush, but the particular contour of the passage way is not of significance.

From the foregoing construction it is felt that the use of the device will be obvious. The bracket 10 is mounted upon the arc frame in such position that the brushes will bear equally upon the electrode, and proper connections are made for the electric current and the cooling fluid.

What I claim:

1. A brush holder for a hierarc electrode comprising a frame adapted to support a plurality of brushes in radial position about an axis, a plurality of channel shaped members attached to said frame and radially disposed about said axis having channels open toward and parallel to the axis to hold said brushes, a brush radially slidable in each of said channels, a spring for urging each of said brushes inwardly towards the axis, each within its channel, and a circuitous passageway for cooling fluid extending through said members and having inlets and outlets for supplying cooling fluids thereto.

2. A brush holder for a hierarc electrode adapted for use with an electrode of rectangular cross section, comprising a frame adapted to support a plurality of brushes in radial position about an axis, a plurality of channel shaped members attached to said frame and radially disposed about said axis having channels open toward and parallel to the axis to hold said brushes, a brush radially slidable in each of said channels and having a flat undersurface to engage an electrode of rectangular cross section, a spring for urging each of said brushes inwardly toward the axis, each within its channel, and a circuitous passageway for cooling fluid extending through said members and having inlets and outlets for supplying cooling fluids thereto.

References Cited in the file of this patent UNITED STATES PATENTS 664,649 Kragh Dec. 25, 1900 728,273 Mix May 19, 1903 1,066,175 Barry July 1, 1913 1,076,054 Orr Oct. 21, 1913 1,594,398 Wolkofi Aug. 3, 1926 1,853,609 Goodspeed Apr. 12, 1932 2,121,578 Winter et a1. June 21, 1938 2,347,646 Smith May 2, 1944 2,703,372 Savage Mar. 1, 1955 FOREIGN PATENTS 226,517 Great Britain May 28, 1925

Images