US2333506A - Apparatus for forming bearing metal surfaces on backing metals - Google Patents

Description

Nov. 2, 1943. 3M, ANGEL 2,333,506

APPARATUS FOR FORMING BEARING METAL SURFACES ON BACKING METALS Original Filed May 19, 1941 Patented Nov. 2, 1943 T T o mE APPARATUS For: FORMING BEARING' 1 METAL SURFACES 0N BACKING; MET

ALS

, OharlesM. Angel, Huntington, W. ;Va. Original application May 19, 1941,"S'erial, No.

' 394,202. Divided and this application ber 24, 1941, SerialNo. 420,210

p I 4 Claims. {clues-12 V This invention relates infgeneral to an irnproved apparatus for forming bearing surfaces or liners of copper alloys or the like on objects made'from a diflerent metal such as cast iron;

steel or the like. The present application is a division of my co-pending application Serial No. 394,202, filed May 19, 1941. 1 I More specifically, the'in'vention as shown herein is directed to an improved apparatus for forming and reconditioningshoe and wedge faces, 'hub liners, and journal brasseson locomotive driving boxes, by fusing a copper alloy or other suitable nonierrous metal to a backing offerrous metal. However, it will be understood that the apparatus may be employed for forming and reconditioning other locomotive and railroad car parts and bearings which are used for otherpurpo'ses.

I Heretofore, it has been the practice'to form shoe and wedge and hub liners on locomotive driving boxes, by pouring molten bronzefon-the backing metal and securing the bronze in place by means'of tap bolts and dovetail'sections' in the steel or other ferrous backing material. Considerable difiiculty has been experienced in" obtaining satisfactory, durable driving boxes when formed in this manner since "it has been found that the metal of the bearing surfaces or liners are not fused to'the backingmetal and 'thesur- No'vemprocess of forming liners by fusing the sa'rne'to the backing metal is additionally. improved by the application of excessiveamounts ofmolten bearing orlinermetaI to the backing" metal in sucha; manner that 'themolten metal flows freely past the surface-to which it is to be 'fused,"for a somewhat" prolonged period, of time, that is throughout the time of the pouring operation. A

further importantobjectof the invention is,

therefore, the provision'of' a means for obtaining this prolonged'period of flow Withoutnecessitat- 'ing'the exercise of greatskill on, the part of the operator whereby the liners ma beformed easily,

(rapidly, efliciently, and economically.

? A further object of the invention is the provision of a means for splitting the hub liner casting to allow for expansion and cohtraction'durmg; the pouring and subsequent cooling of the molten metal, 'and thus avoid cracking andsep- 1 aration from theibacking metal; andalso to allow' for movementof the driving box under impactin service should strains occur which would cause the liner to crack. e

Anotherobject ofthe invention is the provision in conjunction with the above apparatus, of 'an improved method of establishing or applying "an initial deposit of .the bearing alloy on the backing metal to improve the union of the parts.

faces crack, separate fromthe backing material during use or become loose around tap bolts and in dovetail sections, making early"replacementp necessary V V e I Accordingly, aprincipal object of' the in'stant invention is the provision of a means whereby the bearlng 'surfa'ces or liners are made an integralpart of the backing metal and an improved union between the two is obtained; a

- Another important object of the invention is 'theprovision' of improved"means whereby the liners maybe reconditioned by abuildin'g'up :method, this apparatus being used to predeter- 1 mine the'depth to which the bearingrmetal will be added so that a substantially accurate bearing formation is obtainedby a'cast'ingp'rocess which requires a minimum amount of skill on the part ofth'e'operator.

To attain the foregoing object, I have provided herein a'system of spillways' which permit exces- It will beunderstood that the apparatus herein described, may be applied for reconditioning worn bearings orliners as well as for thepreparation or formingof entirely new surface bearings, and that where the'surface to be covered by the bearing, driving box'surfaceflor like expressions are used, they are directed to either the actual surface'of the driving box proper or I bearings or liners I to the'w'orn surface of'old which are being reconditione Numerous otherobjectsand' advantages of-the invention will be apparent as it is better understood from the following description, which, when taken-in connection with the accompanyin drawing, discloses a* preferred embodiment sive amounts of molten metal to be applied to the backing metal or to the worn liningvmetal, these spillways taking away the-excess metal when a predetermined thicknessisobtained, and transmitting thetsame to'an ingot mold where it is available'forremelting.

- I, have found that the above recited additive o5 thereof;

'-In the drawing,

Figure l is a top plan used forfor-ming thedrive bearing on a locomotive driving box'; n

Fig, 2 is a side elevational View ratus shown in Fig. 1;- and I Fig: 3- is across sectional view taken on the of the appaof the molten metal.

line 3--3 of Fig. ,1, and showing the flow lines.

Referringto the drawing, and more particu-" Iarly'td Figs. 1, 2 and 3 thereof, the entire asview of the apparatus Y designated as- M:

sembly shown rests upon a suitable fireproof plate 10. A locomotive driving box H to be treated in accordance with the instant invention, is placed upon the plate In with the worn hub liner or hub liner surface extending upwardly from the plate 10. The driving box shown is' of: standard constructionand includes va body 12'', attachment-flanges- I3 and If3a: and attachment lugs l4. I A Preferably before the bearing parts are to the box H as hereinafter-described, thelbox is so treated as to deposit a filin-rof thezbearlihg alloy to the surfaces thereof. One method of accomplishing this is to place copper or copper alloy turnings upon the surfaces to a depth of to A and fuse the lsame -thereto with: a... carbon arc using approximately 158;?! amperes at It will be understood, however, that"- 80 volts. the current used may varywidely under varying conditions'of operation and of materialsb'eing' workedau-poni. Another methodistmuse abearingzalley brazingt rod'and apply-the film with; an

oxyacetylene torch... Another highly satisfactory methodis to electroplate; a film of bearing meta-lsuchas-copper or copperalloy to the surfaces. By so applying :a'; film of: the bearing meter to the: surfaces-,-. an initiaL-deposit obtained which. i-s:- securely fused and} unitedi with the; driving. box: surfaces so, that the laterunion of: the bearings.- proper to the driving -l. I- is facilitated. After; this initial layer-of bearing metal isformed the surface thereon is cleansed as by pick-ling; orv by bombardment with: steel shot, or blasted with an abrasive: material; or,

anyother suitable method ofcleansingthe sur-' face may be: employed. a The assembly shown in liligs. l ,-2 and?) is that vused in forming. the driving hearing. which is fused to tl ie' crown of: the? driving --box andvin cludes a casting band t5; the height. ofwhich is aboveythesurface 'ofi the hub-linerrto be: later Least.v Opposedto the crownsurface of the inside of the driving box and between; lugs thereof,is a-baked sand core Hi, the ring: face. of which; with saidcrownsurface serves asthe vertical walls of the bearingliner-mold: cavity formedadiacent the: cere l- 6;; the core' lil havirlg a lower section: l9 in which is formed an: ingot sump'moldifln f A After the preliminary treatment above described, in which) the initial filmi of bearing metal is formed on: the bearing surfaces: of the dr lvebox H; the box is 'placed'. uponzthe plate lli'wit'h the hub liner surface up. "After-the sandz cores t6 and i=8 have been' placed: in' position: the driving. box is then preferablypreheated to about 900 F.. thisbeing; accomplished; ,in

any desired manner asfor example, by torches .llgiz andli. 1

'- As preViOusIyexpIa-medQ there :are-

hortant- Iactorswhich concern the casting f I the bearing meta-1' on the surfacesof the driving box II. First, it is highly desirablethahthe molten metal be poured in excess-of the volume required for the bearing and that the'excess metal flow freely .past the surfacewherefusion occurs, thus maintaining the temperature of the surface at that. of: the molten metal. In using such a method" it is of course, necessary that the pathof flow of the molten. metal be. sodirected that continuous flow. ast said surface is obtained throughout the pouring operation .and

-' so that the excess metal. is properly disposed of without blocking off or damming JIpq the ilow;

Secondly, it is highly desirable that as the pouring progresses and the approximate dimensions of the desired bearing are reached," further in crease of the bearing dimensions cease and that the excess metal poured thereafter be disposed of after passing through the mold cavity. To the=-end'tl1at'the:abovecharacterjof flow be obtained spillwaysnare provided which-have predetermined levels and which afford an exit for Tthe excess of molten bearing metal and at the same timev determine the path of flow of the metalandeihsurei flow past the surface to which the bearingor liner is to be attached.

Figs. 1, 2 and 3 show a preferred system of spillwaysanw ducts for forming the driving bear- -ing s It wil1-be-see n from these figures that in thev present embodiment, the sand core I6 is prolryided. with a, duct' 24 which serves as a rising Another sand core 18 .is

column for the molten metal. connected at its bottom with the bottom of the driving bearina cavity l.1. preferably through a plurality ot-Yducts 25, 25; 2,1,. 28. and 2.9;. Atspillway an in turnleads fronr thetop of ithe'ductlfi into a downwardly graded. ductii l which in turn carries the molten bearing metal to; the ingot moldzfl I v V e I as):

' From the foregoing: it willbeseenr thatgafter the assembly is sufiicientlyh-heated by; torches 2|, 22..and-- 23, the molteneinetal 'may be poured into the drive bcarirrg mold cavity.- I].. from'thetop as shown at- 3 2 inJ igure The metal then follows the: path shown-by the"a-r,-rows, that-is,

through ducts 25, 26, Il '28 and za sinto the bottom of duct, '.I'hereupon the columnszof molten; metal -will rise-equally in, the cavity [1 and; qu en. due to the creation of,av hydraulic head through. ductsii to 23. inclusive, Thereafter the metal risesdn. each column tc=the height of thejbottom. o;f: therspillway 30,; wh ic hheight is; predetermined to determine the heightof the drive -bearing. up the casting ring; l5. From. the

the ingot-moldlll.

spillway 301 the: metal passes; through duet 3-1. to

With. the above described assemblyand system of ducts; and spillwaysg it. .will be seen' that,- the molten: metaI may-becontinuously added, 'bQgthe top ot mold cavity-Ltandmust necessarilyi pass entirely 'therethrough since the only exit; is at 5 *thebottom: thereof .2 Furthermora-g the :exact seen inFigs. v1: and SQ-is determinedaby the-level length; ofthe. drive bearing.- (height thereof .Jas

of the bottom of spillway 30, since the escape is caused by the existence of :the. above;:m entioned hydraulic head. I have found that generally the pouring. of 50%. excess molten' meta-lis. suflicient to insure 8n good union-between the bearing": metal and the driving-box surface, but it willibe understood that this 'quantity may bevaried intac- ,cordance with. varyingconditions. It 'is to be the pouring! operation shouldfolloW thepath defined. by the arrowsA, B, C, and-D-shown in noted: that the; preferreds'path. of the ladle during This' duct 24 is ably the bearing forming operations are performed in the order described herein.

It is to be understood that the forming operations are preceded by the earlier described formation of the initial thin layer or coating by any preferred or desired method, such as electrodeposition, whereupon the surface is suitably cleaned. This procedure may then be followed by a final fusion heating of the entire driving box II to create a strong union between the various bearing linings and the surfaces of the driving box.

It will be seen that with the apparatus herein described, the bearings will be of uniform and even strength and texture and will be fused to the driving box surfaces throughout their surface area. Furthermore, due to the method employed, the bearings will be free from fissures and weak spots where cracking and deterioration may occur.

It will be understood that whenever a bearing surface so applied becomes worn, it can be reconditioned and restored to its original size by employing the apparatus herein described. Care should be taken to have the part to be rebuilt cleaned and preheated to proper temperature before applying additional bearing metal. I

It is thought that the invention and many of its attendant advantages will be understood from' the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the devices mentioned herein without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the forms hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. In apparatus for forming a drive bearing for a locomotive driving box or the like, a mold cavity, the crown surface of the drive box constituting one wall of the cavity, a sand core between the legs of said driving box, said core having a surface opposing the crown surface of the driving box to provide, with said crown surface, a mold cavity conforming substantially to the configuration of the cross section of the drive hearing to be formed, an ingot sump in said sand core, a flow passage for conducting molten bearingmetal-from said cavity to said sump, said passage including a vertical rising column duct I in said sand core, a duct leading from the botdriving box as one wall, an ingot sump, a passage for conducting molten metal from said cavity to said sump, said passageincluding a duct which connects with the bottom of said'cavity, a rising column duct which connects with said last named duct and a duct for conductin molten metal from said rising column duct to said sump.

3. In apparatus for forming a drive bearing for a locomotive drive box or the like, a mold cavity having the inner crown-surface of the driving box as one wall, an ingot sump and a passage for conducting molten metal from said cavity to said sump, saidpassage including a plurality of ducts which connect with the bottom of said cavity throughout its horizontal length,

a rising column duct which connects with said wall thereof, said core being built up above the hub liner surface of said box, a casting ring mounted on the hub liner surface for building up the mold cavity above the level of the hub liner surface, and ducts for conducting molten metal away from said cavity, said ducts including an intermediate hydraulic column through which molten metal must pass upwardly when escaping from said cavity.

CHARLES M. ANGEL.

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