US2062795A - Manufacture of compound strip - Google Patents

Description

Dec. 1, 1936. R. D. PIKE 2,062,795

MANUFACTURE OF COMPOUND STRIP Filed May 4, 1931 2 Sheet s-Sheet 1 A TTORN E YS.

- R. D. PIKE 2,795

MANUFACTURE OF COMPOUND STRIP Filed May 4,. 1931 2 Shets-Sheet 2 Ill W Kiwi/x @J AVMZ M W 7% ATTORNEYS.

Patented Dec. 1, 1936 UNITED STATES MANUFACTURE OF COMPOUNDSTRIP Robert 1). Pike, Diablo, calm, assignor to Kalif Corporation, Emeryville, .Galif.,,a'corporation of Delaware Application May 4, 1931, Serial Nor-534,723 4 claims. (o1.- ill-70.2)

My invention relates generally to a method for the continuous manufacture of compound strips,

and specifically, to the manufacture of bronze lined steel strip in which the bronze liner is integrally welded or otherwise integrally united to one face of the steel strip andin some cases over one or both of the faces adjacent thereto or edges.

An object of my invention is to provide a method whereby a simple-single strip may be converted into a compound strip.

Another object of my invention is to provide a method for regulating the thickness of the ma-' terial applied to the original strip.

Another object of my invention is to provide a 'method for varying the thickness of the material applied to the original strip. Another object of my invention is to produce a compound strip, one element of which is of material having characteristics which make it suitable for use as a bearing surface, while the other element thereof is of stifier and stronger backing material. Another object of my invention is to provide a method for producing a strip of the character described for use in bearings wherein the bearing material is of a thickness only slightly in excess of that required for bearing purposes, so that only the minimum amount thereof need be machined away.

Other objects of my invention will be apparent on reading the appended description taken in connection with the accompanying drawings.

My invention comprises broadly the application of a metal heated to such a point that it will flow,

said application being preferably to a metallic strip with the use of means to control the thickness of the applied material and to make it substantially uniform before or at the time of hardening. The preferred method of accomplishing this result is to pass a strip of metal .through a bath of another metal in molten or fluent condition and to form what might be termed a wave of such fluent metal, which may be constant as to its dimensions 'and/or its position at the place 4 where the strip emerges from the molten metal,

and to cause the hardening or solidification of the material forming the wave as the strip to be coated passes therethrough and away from the bath. 4

On the accompanying drawings, I have illustrated more or less diagrammatically my method and the means which may be employed in practicing it. 55 Fig. 1 is an elevational view partly in section of a general schematic lay-out of the principal units of apparatus.

Fig. 2 is a longitudinal section of the spreader.

Fig. 3 is a plan view of Fig. 2.

Fig. 4 is a view looking in the direction of the 5 arrows IV-IV of Fig. 2.

Fig. 5 is a view similar to Fig.- 1 but of a modification.

Figs. -6, 7 and 8 are cross sectional views each of different products produced by my process. 10 Referring to Fig. 1, power rolls III are employed to drawa continuous strip or ribbon 30 to be coated, say of steel, through a furnace l l'which is so operated that the strip will emerge at a temperature at about 1470 to 1650 F. Control power 15.

rolls 12 are provided at the other side of the furnace, both sets of power rolls being so operated that the tension on the hot strip is maintained at a suitably low point. The strip may be fed into the furnace in any suitable manner and from any 20 suitablesource, but I prefer to feed it from rolls or reels I 3 up over the usual guide rolls l4; and I prefer to weld the end of a strip as it leaves the roll or reel l3 to the beginning of another roll strip in order that the process may be continuous 25 and without interruption.

Power rolls l5 are used in cooperation with the rolls l0 to provide and maintain a downwardly extending loop H5 in the steel strip, this loop remaining practically stationary "with re- 30 spect to theapparatus as the strip passes on. This loop passes beneath a diving board l1 which extends below the level of a bath of molten metal I8 in the pot or crucible l9 which is set in the furnace 20, which may be of any desired type, 35 to keep the molten metal at a suitable tempera: ture, which for special bearing bronze compositions is best 2000" to 2100 F.

I may use'bearing bronze mixtures consisting of about 25 to 30 parts by weight of lead, and 40 the balance copper, suflicient to make a total of 100 parts by weight of metal. I sometimes use a bronze containing lead and copper in about the proportions stated and also containing small amounts of other material, as for example, not 45 over 6% of tin or not over 3% of nickel. I prefer bronzes which, of course, have the desired bearing characteristics, and which are easily rolled out. Theuse of bronzes which contain little, if any, lead, and usually from 5 to 10% of 5 tin, 2% to 5% of zinc, and the balance copper, allowing, of course, for minor small amounts of accidental impurities, aid in producing a very desirable compound strip to be used 'for making bearings. Such bronzes I usually maintain molten at temperatures of about 2000" to'2100 F.

Molten flux 2| fioatson the bath of molten metal at the side of the diving board I! at which the strip enters. I have found a flux consisting of anhydrous borax 80 percent, cryolite percent, and boric acid, 10 percent, to be very'ef- 'fective and especially with respect to the particular metal mixtures above mentioned, and it .will be in a highly fluid condition at the temperature of the molten metal, since the melting point of such flux is about 1200 F.

I have also found it advantageous at times to place a fine layer of such flux in powdered form on the strip where it enters the furnace ll be-- type suitable for this purpose.

I provide a supporting or aligning surface 23 to guide the strip as it emerges from the fluid bath. I also provide a flat member 24 so positioned as to leave a relatively small opening 25 into which the fluent material flows as the strip to which the metal is to be applied passes upwardly past the aligning surface 23, and as the applied metal is carried upwardly by such strip, the fluid material is replenished from the bath through the opening 25 into the pool 26;- and I provide means for causing the metal in such pool to form what might be termed a wave 21 against the strip as it this by blowing the metal, and this I find maybe accomplished by means of one or more steam jets 28 which are so adjusted and arranged as to blow a continuous wave of molten metal onto the surface of the strip and which is thereby carried up and out of the bath by its adherence to the strip as it moves upwardly.

One-or more nozzles 29 for blowing any suitable cooling fiuid ontothe moving strip are provided, and this coolingfluid may be steam. It impinges onto the strip in a zone above the level of the bath of metal and solidifies or freezes the metal onto the face of the strip.

Ordinarily the resulting strip will be like that illustrated in Fig. 6 where 30 designates the steel backing and 3| designates the applied metal, for example, bronze bearing-metal. It will be seen from Fig. 6 that the two strips 30, 3| are each as wide as the other-and that they contact with each other at one face. It is sometimes desirable to have the applied metal 3| extend around over the edges of the backing strip 30 to form the parts 32, 33 (Figs. 6 and '7) which are integral with the part 3|, and to accomplish this I provide one or more steam nozzles 28 (Fig. 4)

at each edge of the strip. It will now be apparent that if part 32 is desired at one edge of the backing strip only, as illustrated in Fig. 8, then one or more nozzles 28 will be provided or used only at the edge of the strip which it is desired to cover.

The mere passage of the backing strip through the metal, as described above, serves to plate or coat the strip uniformly with a very thin layer of the coating material, and in the case of a steel strip to which a bearing bronze is applied this coat will be from 1/ 1000ths to 2/1000ths of an inch thick; but the nozzle action, as above described, will provide a layer of any desired thickness within practical limits for use as a bearing, and this thickness may be controlled by intensity of the blast, dimensions of the pool, dimensions of the opening 25, andby other condipasses upwardly. I prefer to do which is defined in the appended claims.

tions of operation as will now be apparent. A water spray 24 is generally provided for cooling the combined strip and this may then be passed through rolls of suitable design for forming into bearings'or it may be otherwise disposed of at least temporarily, as may be found desirable.

. My process may be used for applying a great many materials to many different backing materials, and when using my process in the'manu- .facture of steel backed bronze faced bearings I find the above described apparatus and method suitable.

Naturally variations will be made in details in using my process with respect to different maeriais.

In Fig. 5 I show a schematic train of equipment which I prefer for coating the steel or bronze backing strip-with Babbitt metal. The backingstrip 34 may be drawn from a rollv 35 and then passed through afurnace 36, from which it emerges at a temperature of about 500 to 600 F., and it then passes through the tinnlng bath31which generally comprises an iron tank 38 suitably heated by means (not shown) and which contains a bath of tin at a temperature of about 600 F. This tank is likewise provided with a diving board 39 on the entrance side of which there is confined abath of flux 40 which may be of any usual type used in theart of tinning.

The strip to which thebabbitt is to'be applied passes underneath theroll 4| and then out of the bath over the roll 42. The strip then passes into the second bath 43, consisting of molten Babbitt metal which is preferably maintained at a tem-.- perature; of 800 to 900 F. This bath may be provided with a diving board 44 anda fluxbath 45. Although it is not necessary to employ a flux bath over the babbitt if the tin bath be used, it

should be used if the tin bath is omitted. I prefer, however, to employ the tin bath and to move the-strip rapidly therefrom into the babbitt so as to prevent oxidization of the tin coating. To prevent such oxidization I may enclose the path of the strip from the point where it leaves the tin bath-to the point where it enters the babbitt bath or the flux over the babbitt and all such enclosure with a non-oxidizing atmosphere in order to completely prevent the formation of even the minute film of oxide on the newly tinned surface. On emerging from the babbitt bath the.

strip is subjected to the action of a lining nozzle and allied parts, as previously described with respect to Fig. 1, such parts being best illustrated in Fi 2.

It is to be understood, of course, that asubmerged roller M (Fig. 5) may be used in place-of the loop l6 (Fig. 1) and vice-versa, since both of these have the function of causing submergence of the backing strip to be coated.

Adherence of metal to any particular face of the strip may be prevented when desired by the application thereto of material which will adhere thereto and prevent contact of the metal therewith.

I have described specific embodiments of my invention inorder to illustrate it, but not as'a limitation thereof; and it is to, be understod that many changes may be made without departing from the spirit of the invention, the scope of Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. The method of forming a compoundstrip comprising a layer of iron or steel and a layer of plastic bronze directly bonded thereto, which method comprises maintaining a molten bath of said plastic bronze at a temperature of about 2000" F. to 2100 F., deforming the surface thereof into a sheet-like form, passing a strip of iron or steel through said molten metal and out therefrom in contact with said sheet-like form, and rapidly cooling the resulting plural layer strip.

2. The method of forming a compound strip comprising a layer of iron or steel and a layer of plastic bronze directly bonded thereto, which method comprises maintaining a molten bath of said plastic bronze at a temperature of about 2000 F. to 2100 F., deforming the surface thereof into a sheet-like form, passing a strip of iron or steel through said molten metal and out therefrom in contact with said sheet-like form, and

chilling the plural layer strip.

g3. The method which comprises forming a molten layer of bearing bronze on a strip 01 iron or steel under conditions to form a compound metal strip which will be unitary on cooling, which comprises passing said strip of iron or 4. The method which comprises forming a molten layer of plastic bronze on a strip of iron or steel under conditions to iorm'a compound metal strip which will be unitary on cooling, which comprises passing said strip of iron or steel into and outof a molten bath ofsaid plastic bronze and at the point of egressproviding and supporting with a gaseous blast on said strip of iron or steel as it moves along a molten layer of said plastic bronze which is too great-tor all said plastic bronze to remain unsupported in molten condition on said iron or'steel, and freezing said 20 molten metal before it can run 01!.

ROBERTD. m.

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