US2893640A

US2893640A - Rail bond and method of installing the same

Info

Publication number: US2893640A
Application number: US414100A
Authority: US
Inventors: Ralph T Lowerre
Original assignee: United States Steel Corp
Current assignee: United States Steel Corp
Priority date: 1954-03-04
Filing date: 1954-03-04
Publication date: 1959-07-07
Anticipated expiration: 1976-07-07

Description

July 7, 1959 R. LOWERRE 7 2,893,640

RAIL BOND AND METHOD OF INSTALLING THE SAME Filed March 4, 1954 2 Sheets-Sheet 1 R41. PH 2'. LOWE/7R5,

ln's Attorney.

July 7, 1959 R. T. LOWERRE RAIL BOND AND METHOD OF INSTALLING THE SAME 2 Sheets-Sheet 2 Filed March 4, 1954 v //V VE/V T0/'?.' HAL PH 7 LOWER/PE,

his Attorney.

United States Patent Ralph T. Lowerre, Bedford, Ohio, ne to United;

This invention relates to a rail bond and to a method of installing. he-same and s a alt-bo not mechanically attached to the rail. Mechanically attached rail bonds have; the; disadvantaged heing-difiicult and expcn i et ara y to the railthat-seas t hasbe proposedt'ofweld rail bonds to the Wh-ilmsnch bonds have, been utilized to some entent they also, have certain disadvantages which have pr vented thernfrom supplanting, mechanically applied nds. If} therail isnot preheated before welding on heat treated after welding-,1 theheat of the welding operation will cause the, stru'cture of the steel in the fail to change -to martensi'te, being detrimental to If rail; is preheated prior to installation of thehond, the cest is increased sdthat there is no advantage qver mechanically applied bonds. If the rail is heat treated after welding, the installed bond is damaged and its life seriously impaired.

It is therefore an object of my invention to provide a rail bond which can be readily and inexpensively applied to a rail without prior heating, without postheating after welding, and without drilling the rail as necessary for a mechanically applied bond.

Another object is to provide a method of making and attaching such a rail bond to a rail.

These and other objects will be more apparent after referring to the following specification and attached drawings, in which:

Figure 1 is a top plan view of a bond applied to a rail;

Figure 2 is a view showing the bond in one stage of its manufacture;

Figure 3 is a view of a terminal of the bond prior to its installation;

Figure 4 is a view taken on the line IVIV of Figure 3;

Figure 5 is a plan view of the equipment used in installing the bond;

Figure 6 is a sectional view taken on the line VI-Vl of Figure 5; and

Figure 7 is an end view of the mold of Figure 6 looking from the left hand end thereof.

Referring more particularly to the drawings, the reference numeral 2 indicates a flexible conductor which is preferably a stranded wire structure made of copper or bronze. A copper sleeve 4 is fastened to each end of the conductor 2 and a thin metal buffer plate 6 is fastened to the sleeve 4. Plate 6 has a generally elliptical portion 8 and a sleeve portion 10 which is wrapped around the sleeve 4 and mechanically locked in place. A sheet 12 'of material having a relatively low melting point with respect to plate 6, such as solder is attached to the portion 8 by bending its longitudinal edges 14 therearound as shown in Figure 4. Instead of applying the layer of solder mechanically it may be applied as a coating. The plate 6 need not be the exact shape shown, it being understood that it is only necessary to have a portion similar to portion 8 which can be fastened to the sleeve 4 in 2 anysuitahle manner. For example,, instead, of the rne chanical connectionshown the-parts. may. bebrgazed}. The, sleeves. 4.;canalso beomittedbut are. desirable in OI'dQr; to, keep the strands of. the member 2. fromspreading In assembling, the rail bond on the rails. R, a. mold. or apair. of.mo1ds.1.6.are provided. Each. mold includesa, crucible 1.8., asprite 20,. and. a cavity 22.. The cavity. 22 is open on theside toward the rail R and hasa notch 2.4. at one end forv receivingthe sleeve. 4, or 10-. A nt l nk p ti n 6 s p ov d d a oun e. mold cavity. adjacent the. rail. As shownin Figure. 5, two. mold's..16 ,are progvided sothat the bond can. be; attached, to, adjacentrail. ends-at. the same. time. The molds, 16;? are. attached. to a uyshaped member. 28 by means.- of. brackets 30, screws: 32 and bolts 34. A rod; 36. ex;=

tends from the base; of the. U.-shaped member 28, away;

from thev molds 16. A jaw. 38; having. a downwardly. extending portion 40 is slidablymounted.

onithe rod

3,6; A. n u t 42.fis mounted on the threadedend of the rod.3 6,. A, spring 44. is. arranged; on the rod 36. betweenthejavv. 38'. and, a member 46. which bears. againstthe nut. 42.. In fastening the rail, bondv to. the. rail ends, the molds, 16. are a-ttached.to.the. rail heads,.adjacent. the ends of the rail in, the desired position. as shown: in Figure. 5, the.

body of the. molds, and the; jaw portion 40.. grippingthe. railhead therebetween. The. spring 44.serv es.1 to urgev the jaw. 38. toward. the molds, 16. The force exerted by: the spring 4.4- may be; varied: by. loosening on tightening, the 11 1 42,, adjustment alsqserves; to. compensate; for different widths of rail heads. It will be understood that the exact construction of the molds 16 and the means for fastening the molds to the rail may vary. Suitable molds and clamping devices are shown in the patents to Cadwell Nos. 2,251,820, dated August 5, 1941, 2,262,755, dated November 18, 1941, and 2,276,- 823, dated March 17, 1942. One of the plates 6 is inserted in the cavity 22 of each of the molds, the plate 6 resting in the counterbored portion 26 with the sleeve 4 or 10 in the opening 24. In this position the solder 12 will be in contact with the rail. An exothermic welding mixture 48 is placed in the crucibles 18 with the sprues 20 being closed by means of a destructible seal 50. Ignition of the mixture 48 produces molten welding metal which destroys the seals 50 and discharges into the mold cavity 22 which is shaped to give the desired contour to the terminal fitting. This molten metal forms terminal fitting 52 which is integral with the buffer plate 6 and the end of the conductor 2. The heat of the molten metal in the cavity causes the solder to melt and fuses the plate 6 to the rail R. The buffer plate 6 is thin enough to enable suflicient heat to penetrate therethrough to carry out the soldering operation, but is of sufiicient thickness to prevent sufiicient heat from passing into the metal of the rail to change its structure. Various types of metal may be used in the plate 6 which is preferably formed of rolled material. For example, low carbon steel, austenitic stainless steel and copper have been used. In each case, plate 6 after its attachment to the rail will have a structure composed of small grains characteristic of worked metal in the portion adjacent the rail and a structure composed of large grains characteristic of the annealed metal in the remaining portion. The grains of the last portion will increase in size toward the surface thereof remote from the rail surface. If a steel buffer plate is used the portion adjacent the rail has a structure composed of pearlite in a matrix of ferrite and the remaining portion a structure composed of martensite in a matrix of ferrite with the martensite content increasing in percentage toward the surface remote from the rail. In the case of copper, the portion of the plate adjacent the rail has a structure composed of elongated grains characteristic of worked copper and the portion E ented. July 1.9.5.91

remote 'from the rail a structure composed of large equiaxed grains characteristic of annealed copper with the grains decreasing in size and changing from large equiaxed shape to elongated shape from the portion of the plate remote from the rail to the portion adjacent the rail. The thickness of plate 6 may vary somewhat but is preferably between about .035 and .050 inch.

While several embodiments of my invention have been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

p 1. The method of making and attaching a rail bond to a rail comprising placing a thin metal buifer plate against the rail with a soldering material between the plate and rail, placing a mold against the plate and around an electrical conductor, flowing molten metal into said mold to form a terminal fitting integral with the butter plate and the conductor, said soldering material having a melting point lower than the melting points of said buffer plate and said molten metal, and correlating the heat of the molten metal, the heat penetration through the buffer plate and the melting temperature of the soldering material to cause the heat from the molten metal to solder the plate to the rail without changing the metallurgical structure of the rail.

2. A rail bond connection comprising an electrical conductor, a buffer plate having solder on the face thereof adjacent the rail, and a cast metal terminal integrally united with one end of said conductor and said bufier plate, said solder having a melting point lower than the melting points of said buffer. plate and said cast metal, said bufi'er plate being interposed between said conductor and said rail and having at least coextensive contact with said cast metal terminal, said cast metal terminal at least partially surrounding said conductor end, said butter plate being connected to the said rail by said solder.

3. A rail bond connection according to claim 2 in which said bufier plate is made of steel with the portion thereof adjacent the rail having a structure composed of pearlite in a matrix o'f ferrite and the remaining portion a structure composed of martensite in a matrix of ferrite.

4. A rail bond connectionaccording to claim 2 in which said butter plate is made of copper with the portion thereof' adjacent the rail having a structure composed of elongated grains characteristic of worked copper and the portion remote from the rail having a structure composed of large equiaxed grains characteristic of annealed copper.

References Cited in the file of this patent UNITED STATES PATENTS Hicks Mar. 10, 1953